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    Exact hydrodynamic description of pilot plant Oldshue-Rushton contactor: a case study with the introduction of selenium and tellurium into reaction system

    , Article International Journal of Environmental Analytical Chemistry ; Volume 102, Issue 16 , 2022 , Pages 4191-4207 ; 03067319 (ISSN) Shakib, B ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
    Taylor and Francis Ltd  2022
    Abstract
    In this paper, the hydrodynamic behaviour of the chemical reaction system (selenium, tellurium, and TBP) was interpreted in the Oldshue-Rushton extraction column. The optimum operating parameters for extracting the selenium and tellurium from chloride medium were carried out by using the batch experiments. The feed acidity of 5 molar and solvent phase with 20% (v/v) TBP in kerosene were optimised to examine the hydrodynamic parameters of the mentioned column. The impacts of operating variables such as rotor speed, inlet aqueous phase velocity, and inlet solvent phase velocity on the dispersed phase hold-up, mean drop size, slip velocity, drop size distribution, and extraction rate were... 

    Spectroscopic Study and Characterizing of Selenium Dioxide Complex with Pyridoxine(PN-Se):Interaction Between (PN-Se)and Bovine Serum Albumin

    , M.Sc. Thesis Sharif University of Technology Jamali, Moein (Author) ; Mohamadi Boghaei, Davar (Supervisor)
    Abstract
    Temporary existence of some molecules like medicines in body and also existence of diagnostic agents in biological systems and study of the interactions of biomolecules with these agents is a matter of interest. It also may have an important role in design and synthesis of new drugs. Serum Albumin is the most abundant protein in circulation system in the body. So far, many studies about the interaction of this protein with different compounds have been undertaken. The aim of this paper was to synthesize selenium complex and analyze its potential biochemical activity in vitro. The concrete work falls into two parts:(1) to synthesize the selenium-pyridoxine compound (PNSe) (2) to probe into... 

    Investigation on the Ability of Pseudomonas Putida Bacterium for Biosorption of Se(IV) from the Aqueous Solutions

    , M.Sc. Thesis Sharif University of Technology Esmaeili Doabsari, Fatemeh (Author) ; Outokesh, Mohammad (Supervisor) ; Keshtkar, Alireza (Supervisor) ; Sohbatzadeh, Hozhabr (Co-Supervisor)
    Abstract
    In this study, biosorption of selenium by Pseudomonas putida bacteria was investigated in both single and binary uptake systems. Bacteria cells were immobilized in the chitosan beads, to study impact of microorganism entrapment on the sorption capacity of the fabricated adsorbent. Uptake capacity increased by the entrapped bacterial weight percent up to 20 wt. %; but thereafter, sorption capacity gradually leveled off with an increase in the loading percentage of the bacterial cells.The effects of the three process variables including pH (2-6), biomass dosage (0.5-2.5 g/L) and initial concentration of selenium (50-250 mg/L) on the uptake performance of adsorbent were investigated, and... 

    Proficiency of tellurium extraction in pulsed disc and doughnut columns

    , Article Separation Science and Technology (Philadelphia) ; Volume 56, Issue 18 , 2021 , Pages 3092-3105 ; 01496395 (ISSN) Shakib, B ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
    Taylor and Francis Ltd  2021
    Abstract
    In this research, the separation of tellurium from selenium was studied from chloride solution by TBP extractant. In the batch experiments, the experimental findings indicated that the feed acidity, TBP concentration, and contact time were optimized to achieve the high separation factor. In continuous mode of pulsed disc and doughnut column, the impacts of operating parameters have been discussed on the distribution coefficients of selenium and tellurium, and mass transfer enhancement. A new model for predicting Koca was proposed in terms of holdup values, Sherwood, Reynolds, and Schmidt numbers, which has an acceptable agreement with the mass transfer data. © 2020 Taylor & Francis Group,... 

    Exact hydrodynamic description of pilot plant Oldshue-Rushton contactor: a case study with the introduction of selenium and tellurium into reaction system

    , Article International Journal of Environmental Analytical Chemistry ; 2020 Shakib, B ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
    Taylor and Francis Ltd  2020
    Abstract
    In this paper, the hydrodynamic behaviour of the chemical reaction system (selenium, tellurium, and TBP) was interpreted in the Oldshue-Rushton extraction column. The optimum operating parameters for extracting the selenium and tellurium from chloride medium were carried out by using the batch experiments. The feed acidity of 5 molar and solvent phase with 20% (v/v) TBP in kerosene were optimised to examine the hydrodynamic parameters of the mentioned column. The impacts of operating variables such as rotor speed, inlet aqueous phase velocity, and inlet solvent phase velocity on the dispersed phase hold-up, mean drop size, slip velocity, drop size distribution, and extraction rate were... 

    Spectrophotometric Study of Formation of Donor-Acceptor Adducts of Selenium Dioxide with Amines and Pyridine like Bases

    , M.Sc. Thesis Sharif University of Technology Saniepay, Mersedeh (Author) ; Mohammadi Boghaei, Davar (Supervisor)
    Abstract
    Donor-acceptor adducts of selenium dioxide were formed with tree aromatic amines, two aliphatic amines and tree pyridine like bases. Characterization of these adducts were done through UV-Vis Spectrophotometer and IR Spectrophotometer and NMR Spectroscopy. In addition, the stoichiometry of these adducts were identified by elemental analysis (CHN). To approve the existence of selenium, Atomic absorption instrument was used.The results obtained from the entioned methods show that the adduct formation between selenium dioxide with amines and pyridine like bases are in following order: p-phenylen diamine.SeO2>NH5.SeO2,en.SeO2,cyclohexylamine.SeO2,... 

    Relationship between serum level of selenium and metabolites using 1hnmr-based metabonomics in parkinson's disease

    , Article Applied Magnetic Resonance ; Volume 44, Issue 6 , January , 2013 , Pages 721-734 ; 09379347 (ISSN) Fathi, F ; Kyani, A ; Darvizeh, F ; Mehrpour, M ; Tafazzoli, M ; Shahidi, G ; Sharif University of Technology
    2013
    Abstract
    Parkinson's disease (PD) is a neurodegenerative disease, which is not easily diagnosed using clinical tests and the discovery of proper methods would be a major step towards a successful diagnosis. In the present study, we employed metabolic profiling using proton nuclear magnetic resonance spectroscopy to find metabolites in serum, which are helpful for the diagnosis of PD. Classification of PD and healthy subject was done using random forest. Serum levels of selenium measured by atomic absorption spectrometry in PD group were lower than the serum selenium levels in the control group. The metabolites causing selenium changes in PD patients were identified using random forest, and a model... 

    A metabonomics investigation of multiple sclerosis by nuclear magnetic resonance

    , Article Magnetic Resonance in Chemistry ; Volume 51, Issue 2 , DEC , 2013 , Pages 102-109 ; 07491581 (ISSN) Mehrpour, M ; Kyani, A ; Tafazzoli, M ; Fathi, F ; Joghataie, M. T ; Sharif University of Technology
    2013
    Abstract
    Multiple sclerosis (MS) is a nervous system disease that affects the fatty myelin sheaths around the axons of the brain and spinal cord, leading to demyelination and a broad range of signs and symptoms. MS can be difficult to diagnose because its signs and symptoms may be similar to other medical problems. To find out which metabolites in serum are effective for the diagnosis of MS, we utilized metabolic profiling using proton nuclear magnetic resonance spectroscopy (1H-NMR). Random forest (RF) was used to classify the MS patients and healthy subjects. Atomic absorption spectroscopy was used to measure the serum levels of selenium. The results showed that the levels of selenium were lower in... 

    Investigation of precursors concentration in spray solution on the optoelectronic properties of CuInSe2 thin films deposited by spray pyrolysis method

    , Article Journal of Materials Science: Materials in Electronics ; 2020 Hashemi, M ; Ghorashi, S. M. B ; Tajabadi, F ; Taghavinia, N ; Sharif University of Technology
    Springer  2020
    Abstract
    Copper indium selenide CuInSe2(CISe) thin films were deposited by chemical spray pyrolysis (CSP) method of CuInS2(CIS) and subsequent selenization process. To study the effects of solution concentration, we prepared different precursors solution of CIS including different amount of indium salts from 0.025 to 0.100 M with In/Cu 1.25 and S/In 4. These results propose that solution concentration is critical for inflecting the morphological, optical, electrical, and electrochemical characteristics of solution-processed CISe films and device performance. The studied morphological properties of deposited samples were homogenous, crack-free with large grains in indium salt concentrations more than... 

    Investigation of precursors concentration in spray solution on the optoelectronic properties of CuInSe2 thin films deposited by spray pyrolysis method

    , Article Journal of Materials Science: Materials in Electronics ; Volume 32, Issue 21 , 2021 , Pages 25748-25757 ; 09574522 (ISSN) Hashemi, M ; Ghorashi, S. M. B ; Tajabadi, F ; Taghavinia, N ; Sharif University of Technology
    Springer  2021
    Abstract
    Copper indium selenide CuInSe2(CISe) thin films were deposited by chemical spray pyrolysis (CSP) method of CuInS2(CIS) and subsequent selenization process. To study the effects of solution concentration, we prepared different precursors solution of CIS including different amount of indium salts from 0.025 to 0.100 M with In/Cu 1.25 and S/In 4. These results propose that solution concentration is critical for inflecting the morphological, optical, electrical, and electrochemical characteristics of solution-processed CISe films and device performance. The studied morphological properties of deposited samples were homogenous, crack-free with large grains in indium salt concentrations more than... 

    Rapid quantitative elemental analysis using artificial neural network for case study of Isfahan Miniature Neutron Source Reactor

    , Article Journal of Radioanalytical and Nuclear Chemistry ; Volume 331, Issue 11 , 2022 , Pages 4479-4487 ; 02365731 (ISSN) Asgari, A ; Hosseini, S. A ; Sharif University of Technology
    Springer Science and Business Media B.V  2022
    Abstract
    In this study, new method for NAA purposes at 30 kW Isfahan MNSR is suggested. An algorithm based on ANN is proposed to quantitatively predict the unknown elements with no need standard sample. A three-layer feed-forward ANN with back-propagation algorithm has been used to determine concentration of selenium and fluorine in Multiple Sclerosis patients and healthy people blood samples. Predicted concentration of elements show good agreement between new method and experiment results. The correlation coefficient between the experimentally determined and predicted values are 0.99104 and 0.99364, respectively. This method is a rapid and precise approach for elemental analysis. © 2022, Akadémiai... 

    NiSe2Nanoparticles supported on halloysite sheets as an efficient electrocatalyst toward alkaline oxygen evolution reaction

    , Article Energy and Fuels ; Volume 36, Issue 23 , 2022 , Pages 14331-14340 ; 08870624 (ISSN) Taherinia, D ; Hatami, H ; Mirzaee Valadi, F ; Akbarzadeh, E ; Sharif University of Technology
    American Chemical Society  2022
    Abstract
    The oxygen evolution reaction (OER) with its sluggish kinetics has imposed a significant barrier to the sustainable and green generation of hydrogen fuel (via electrolysis of water) and the development of metal-air batteries. In this study, we report an efficient and novel OER electrocatalyst based on NiSe2nanoparticles (NPs) and the naturally abundant halloysite clay mineral. The NiSe2/halloysite nanocomposite (NiSe2/H) was prepared by a simple one-step hydrothermal route. The electrocatalytic performance of the as-synthesized nanocomposite and its components (pristine NiSe2and halloysite) toward OER in 1.0 KOH solution was examined. The NiSe2/H nanocomposite exhibited a significantly... 

    Equatorial magnetoplasma waves

    , Article Physical Review B ; Volume 105, Issue 20 , 2022 ; 24699950 (ISSN) Finnigan, C ; Kargarian, M ; Efimkin, D. K ; Sharif University of Technology
    American Physical Society  2022
    Abstract
    Due to its rotation, Earth traps a few equatorial ocean and atmospheric waves, including Kelvin, Yanai, Rossby, and Poincaré modes. It has been recently demonstrated that the mathematical origin of equatorial waves is intricately related to the nontrivial topology of hydrodynamic equations describing oceans or the atmosphere. In the present work, we consider plasma oscillations supported by a two-dimensional electron gas confined at the surface of a sphere or a cylinder. We argue that in the presence of a uniform magnetic field, these systems host a set of equatorial magnetoplasma waves that are counterparts to the equatorial waves trapped by Earth. For a spherical geometry, the equatorial... 

    Morphological manipulation of solvothermal prepared CdSe nanostructures by controlling the growth rate of nanocrystals as a kinetic parameter

    , Article Journal of Electronic Materials ; Volume 41, Issue 11 , 2012 , Pages 3050-3055 ; 03615235 (ISSN) Zarghami, V ; Mohammadi, M. R ; Fray, D. J ; Sharif University of Technology
    2012
    Abstract
    The morphological manipulation, structural characterization, and optical properties of different cadmium selenide (CdSe) nanostructures are reported. Two different CdSe nanostructures, i.e., nanorods and nanoparticles, were grown by controlling the concentration of precursors (i.e., cadmium nitrate and selenium dioxide) in ethanolamine solvent. By manipulating the kinetic parameter of the process (i.e., growth rate) under constant growth driving force (i.e., degree of supersaturation), the morphology of CdSe nanostructures can be tailored from nanorods to nanoparticles. The optical properties of CdSe nanostructures were investigated using ultraviolet-visible (UV-vis) spectroscopy. The... 

    Synthesis of new 2-aryl-4-chloro-3-hydroxy-1H-indole-5,7-dicarbaldehydes via Vilsmeier-Haack reaction

    , Article Journal of Heterocyclic Chemistry ; Volume 47, Issue 2 , 2010 , Pages 463-467 ; 0022152X (ISSN) Eftekhari Sis, B ; Zirak, M ; Akbari, A ; Hashemi, M. M ; Sharif University of Technology
    2010
    Abstract
    (Chemical Equation Presented) New 2-aryl-4-chloro-3-hydroxy-1H-indole-5,7- dicarbaldehydes were synthesized in three steps from acetophenone derivatives. By oxidation of acetophenones to aryl glyoxals using selenium dioxide and condensation with acetylacetone in the presence of ammonium acetate in water 3-acetyl-5-aryl-4-hydroxy-2-methyl-1H-pyrrols were obtained. 2-Aryl-4-chloro-3-hydroxy-1H-indole-5,7-dicarbaldehydes were synthesized via Vilsmeier-Haack reaction of pyrrole derivatives in moderate yields  

    Self-supported nanoporous Zn–Ni–Co/Cu selenides microball arrays for hybrid energy storage and electrocatalytic water/urea splitting

    , Article Chemical Engineering Journal ; Volume 375 , 2019 ; 13858947 (ISSN) Hosseini, H ; Shahrokhian, S ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    The phase-pure multiple ternary or quaternary metal selenides in energy boosting, have not been reported yet. Here, self-supported porous crystalline Zn–Ni–Co/Cu selenides microballs arrays were constructed by selenation of the designed tubular Cu(OH)2 arrays decorated with ultrathin Zn–Co–Ni tri-metallic hydroxide on carbon cloth substrate. For this rational engineering, a novel precursor sample was firstly prepared by conversion of deposited Cu layer to hollow tubular Cu(OH)2 arrays on carbon cloth, then, Zn-Co–Ni layered ternary hydroxides with a thin layer structure was deposited around this tubular arrays. The selenation with an exciting morphology change from amorphous tube to highly... 

    Pure sulfide Cu2ZnSnS4 layers through a one-step low-temperature PLD technique: Insight into simulation on modified back contact to overcome the barrier of MoS2

    , Article Materials Science and Engineering B: Solid-State Materials for Advanced Technology ; Volume 262 , 2020 Heidariramsheh, M ; Haghighi, M ; Dabbagh, M. M ; Mahdavi, S. M ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    Targeting on the selenium free, pure sulfide kesterite compound (CZTS) allows retention of the higher band gap nontoxic absorber for a single-junction solar cell. In this work, CZTS thin films were deposited by the PLD method and the Structural/optical properties, as well as Mott–Schottky analysis, were studied at different substrate temperatures. Without undergoing the sulfurization process, the single-phase CZTS thin film is prepared at 300 ℃. In the second step, a numerical simulation is performed using the solar cell capacitance simulator to study the effect of the grading layer of MoS(Se)2 on the rear side of pure sulfide kesterite based solar cells. The device with a MoSe2 coated... 

    Photovoltaic performance and electrochemical impedance spectroscopy analysis of CdS/CdSe-sensitized solar cell based on surfactant-modified ZnS treatment

    , Article Applied Physics A: Materials Science and Processing ; Volume 126, Issue 6 , 2020 Samadpour, M ; Dehghani, M ; Parand, P ; Natagh Najafi, M ; Parvazian, E ; Sharif University of Technology
    Springer  2020
    Abstract
    Among the various approaches, ZnS treatment is the most convenient method for reducing the charge recombination in quantum dot-sensitized solar cells (QDSSCs). Here an improved method of ZnS treatment is explained for efficiency enhancement in QDSSCs. To get to the goal of device performance improvement, it is essential to have a uniform deposited layer. We utilized Triton X-100 (TX-100) as a surfactant to the convenient aqueous precursors during ZnS deposition by successive ionic layer adsorption and reaction method. It helps to decrease in contact angle and increase in wettability of the aqueous precursor and results in a more uniform deposited layer. The effect of modified ZnS treatment... 

    The performance of pulsed scale-up column for permeable of selenium and tellurium ions to organic phase, case study: Disc and doughnut structure

    , Article Chemical Engineering and Processing - Process Intensification ; Volume 157 , 2020 Shakib, B ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    A research investigation of the overall mass transfer coefficients, holdup and mean drops of dispersed phase as well as slip and characteristic velocities were carried out in the pulsed scale-up column with disc and doughnut structure for extraction of tellurium and selenium from a hydrochloric acid medium with TBP extractant. The impact of operating conditions containing the pulse intensity, inlet aqueous and solvent phase velocities have been studied on the mass transfer rates, and the special column characteristic. By considering the reactive extraction situations, modified models were derived for predicting of holdup, d32, and slip velocity in this extractor. The axial diffusion model... 

    Magnetoelastic coupling enabled tunability of magnon spin current generation in two-dimensional antiferromagnets

    , Article Physical Review B ; Volume 104, Issue 18 , 2021 ; 24699950 (ISSN) Bazazzadeh, N ; Hamdi, M ; Park, S ; Khavasi, A ; Mohseni, S. M ; Sadeghi, A ; Sharif University of Technology
    American Physical Society  2021
    Abstract
    We theoretically investigate the magnetoelastic coupling (MEC) and its effect on magnon transport in two-dimensional antiferromagnets with a honeycomb lattice. MEC coefficients along with magnetic exchange parameters and spring constants are computed for monolayers of transition-metal trichalcogenides with Néel magnetic order (MnPS3 and VPS3) and zigzag order (CrSiTe3, NiPS3, and NiPSe3) by ab initio calculations. Using these parameters, we predict that the spin-Nernst coefficient is significantly enhanced due to magnetoelastic coupling. Our study shows that although Dzyaloshinskii-Moriya interaction can produce spin-Nernst effect in these materials, other mechanisms such as magnon-phonon...