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    Potentiometric membrane sensors based on zirconyl(IV) phthalocyanine for detection of sulfosalicylic acid

    , Article Talanta ; Volume 63, Issue 2 , 2004 , Pages 371-376 ; 00399140 (ISSN) Shahrokhian, S ; Taghani, A ; Hamzehloei, A ; Mousavi, S. R ; Sharif University of Technology
    Elsevier  2004
    A metallophthalocyanine complex with zirconium(IV) ion in the center (as an oxo-zirconium, Zr=O, group) was used in poly vinyl chloride (PVC) membranes for the selective detection of 5-sulfosalicylic acid (SSA). The resulting electrodes demonstrate Nernstian responses over a wide range of sulfosalicylic acid concentration (10-6 to 10-1 mol dm-3) with a slope of about -29 mV per decade. The influence of lipophilic ion-exchanger sites on the response properties of the electrodes was investigated. The optimal potentiometric response was observed for the electrode in the presence of about 150 mol% of cationic additive (relative to ionophore) in the phase membrane. The electrodes have a fast... 

    The MSA and the individual ionic activity coefficients

    , Article Iranian Journal of Science and Technology, Transaction B: Technology ; Volume 27, Issue 2 , 2003 , Pages 247-252 ; 03601307 (ISSN) Taghikhani, V ; Modarress, H ; Khoshkbarchi, M. K ; Vera, J. H ; Sharif University of Technology
    The mean spherical approximation (MSA) has been applied to accurately correlate the activity coefficients of individual ions in aqueòus solutions of single 1:1 electrolytes. In order to account for changes in the hydration of the ions, the size parameters of the ions are considered to be composition dependent. The values of the size parameters show that the hydration of the ions decreases as the electrolyte concentration increases. Results obtained from the full MSA and from a simplified version of MSA (SMSA), were compared. The use of the simplified version had a small effect on the final results and dramatically reduced the computation of the effort  

    Stabilities and isomeric equilibria in aqueous solution of monomeric metal ion complexes of adenosine 5′-diphosphate (ADP3-) in comparison with those of adenosine 5′-monophosphate (AMP2-)

    , Article Chemistry - A European Journal ; Volume 9, Issue 4 , 2003 , Pages 881-892 ; 09476539 (ISSN) Bianchi, E. M ; Sajadi, S. A. A ; Song, B ; Sigel, H ; Sharif University of Technology
    Under experimental conditions in which the self-association of the adenine phosphates (AP), that is, of adenosine 5′-monophosphate (AMP2-) and adenosine 5′-diphosphate (ADP3-), is negligible, potentiometric pH titrations were carried out to determine the stabilities of the M(H;AP) and M(AP) complexes where M2+=Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, or Cd2+ (25°C; I = 0.1m, NaNO3). It is concluded that in the M(H;AMP)+ species M2+ is bound at the adenine moiety and in the M(H;ADP) complexes at the diphosphate unit; however, the proton resides in both types of monoprotonated complexes at the phosphate residue. The stabilities of nearly all the M(AMP) and M(ADP)- complexes are... 

    Measurement of activity coefficients of amino acids in aqueous electrolyte solutions: Experimental data for the systems (H2O + NaBr + glycine) and (H2O + NaBr + L-valine) at T = 298.15 K

    , Article Journal of Chemical Thermodynamics ; Volume 35, Issue 9 , 2003 , Pages 1553-1565 ; 00219614 (ISSN) Khavaninzadeh, A ; Modarress, H ; Taghikhani, V ; Khoshkbarchi, M. K ; Sharif University of Technology
    Academic Press  2003
    Electrochemical cells with two ion-selective electrodes, a cation ion-selective electrode against an anion ion-selective electrode, were used to measure the activity coefficient of amino acids in aqueous electrolyte solutions. Activity coefficient data were measured for (H2O + NaBr + glycine) and (H2O + NaBr + L-valine) at T = 298.15 K. The maximum concentrations of sodium bromide, glycine, and L-valine were (1.0, 2.4, and 0.4) mol · kg-1, respectively. The results show that the presence of an electrolyte and the nature of both the cation and the anion of the electrolyte have significant effects on the activity coefficients of amino acid in aqueous electrolyte solutions  

    Activity coefficients of electrolyte and amino acid in the systems (water + potassium chloride + DL-valine) at T = 298.15 K and (water + sodium chloride + L-valine) at T = 308.15 K

    , Article Journal of Chemical Thermodynamics ; Volume 34, Issue 8 , 2002 , Pages 1297-1309 ; 00219614 (ISSN) Khavaninzadeh, A ; Modarress, H ; Taghikhani, V ; Khoshkbarchi, M. K ; Sharif University of Technology
    The activity coefficient data were reported for (water + potassium chloride + DL-valine) at T = 298.15 K and (water + sodium chloride + L-valine) at T = 308.15 K. The measurements were performed in an electrochemical cell using ion-selective electrodes. The maximum concentrations of the electrolytes and the amino acids studied were 1.0 molality and 0.4 molality, respectively. The results of the activity coefficients of DL-valine are compared with the activity coefficients of DL-valine in (water + sodium chloride + DL-valine) system obtained from the previous study. The results show that the presence of an electrolyte and the nature of its cation have a significant effect on the activity... 

    Vanadyl and molybdenyl phthalocyanines as ionophores for salicylate-selective membranes coated on graphite electrodes

    , Article Analytical Letters ; Volume 34, Issue 5 , 2001 , Pages 661-674 ; 00032719 (ISSN) Firooz, A. R ; Amini, M. K ; Tangestaninejad, S ; Shahrokhian, S ; Sharif University of Technology
    Salicylate selective electrodes based on oxo(phthalocyanato)-vanadium(IV) [VO(Pc), vanadyl phthalocyanine] and oxo(phthalocyanato)molybdenum(IV) [MoO(Pc), molybdenyl phthalocyanine] are described. The electrodes were prepared by incorporating the ionophores into plasticized poly(vinyl chloride) membranes, which were directly coated on the surface of graphite electrodes. The resulting electrodes demonstrate Nernstian responses over a wide linear range (10-7-10-1 M) salicylate. The electrodes have a fast response time, submicromolar detection limit, and could be used over the pH range of 6-9. The proposed sensors revealed selectivity for salicylate over a number of common inorganic and organic... 

    Optical slab waveguides based on ion exchange method: Fabrication, test, characterization and mathematical profiling

    , Article Iranian Journal of Science and Technology, Transaction B: Technology ; Volume 24, Issue 1 , 2000 , Pages 122-123 ; 03601307 (ISSN) Rashidian, B ; Sheikhi, M. H ; Sharif University of Technology
    In this paper the fabrication, testing and results of inverse profiling of optical slab waveguides in glass are reported. This is the first successful report of fabricating ion exchange optical waveguides in Iran. © Shiraz University  

    Characterization of ionic composition of TSP and PM10 during the Middle Eastern Dust (MED) storms in Ahvaz, Iran

    , Article Environmental Monitoring and Assessment ; Volume 184, Issue 11 , November , 2012 , Pages 6683-6692 ; 01676369 (ISSN) Shahsavani, A ; Naddafi, K ; Jaafarzadeh Haghighifard, N ; Mesdaghinia, A ; Yunesian, M ; Nabizadeh, R ; Arhami, M ; Yarahmadi, M ; Sowlat, M. H ; Ghani, M ; Jonidi Jafari, A ; Alimohamadi, M ; Motevalian, S. A ; Soleimani, Z ; Sharif University of Technology
    Because of the recent frequent observations of major dust storms in southwestern cities in Iran such as Ahvaz, and the importance of the ionic composition of particulate matters regarding their health effects, source apportionment, etc., the present work was conducted aiming at characterizing the ionic composition of total suspended particles (TSP) and particles on the order of ∼10 μm or less (PM10) during dust storms in Ahvaz in April-September 2010. TSP and PM10 samples were collected and their ionic compositions were determined using an ion chromatography. Mean concentrations of TSP and PM10 were 1,481.5 and 1,072.9 μg/m 3, respectively. Particle concentrations during the Middle Eastern... 

    Selective Adsorption of Li+Ion on Lithium Adsorbents

    , M.Sc. Thesis Sharif University of Technology Hajipour, Hengameh (Author) ; Askari, Masoud (Supervisor)
    Interest in lithium sources has been increasing because of wide applications of the metal in high-energystorage lithium batteries and its compounds in otherfields.Lithium appears in lake, brines and several minerals such as spodumene, petallite, and lepidolite. Several methods such as ion exchange (adsorption), solvent extraction, and coprecipitation have been investigated for the extraction of lithium from seawater, brine, and geothermal water. The adsorption method is suitable for recovery of lithium from seawater because certain inorganicion-exchange materials show extremely high selectivity for lithium ions only.The objective of this study is to evaluate the applicability of nano... 

    Comparison of thermochemistry of aspartame (artificial sweetener) and glucose

    , Article Carbohydrate Research ; Volume 344, Issue 1 , 2009 , Pages 127-133 ; 00086215 (ISSN) Rashidian, M ; Fattahi, A ; Sharif University of Technology
    We have compared the gas phase thermochemical properties of aspartame (artificial sweetener) and α- and β-glucose. These parameters include metal ion affinities with Li+-, Na+-, K+-, Mg+2-, Ca+2-, Fe+2-, Zn+2-ions, and chloride ion affinity by using DFT calculations. For example, for aspartame, the affinity values for the above described metal ions are, respectively, 86.5, 63.2, 44.2, 255.4, 178.4, 235.4, and 300.4, and for β-glucose are 65.2, 47.3 32.9, 212.9, 140.2, 190.1, and 250.0 kcal mol-1, respectively. The study shows differences between the intrinsic chemistry of aspartame and glucose. © 2008 Elsevier Ltd. All rights reserved  

    Comparison of acidity and metal ion affinity of D-Glucosamine and N-acetyl-D-glucosamine, a DFT study

    , Article Journal of Molecular Graphics and Modelling ; Volume 98 , April , 2020 Mosapour Kotena, Z ; Fattahi, A ; Sharif University of Technology
    Elsevier Inc  2020
    The derivatives of glucose such as glucosamine (β-D-GlcN) and N-acetyl-D-β-glucosamine (GlcNAc) are significant in several biological systems. D-GlcN has been used widely to treat osteoarthritis in humans and animal models as well as GlcNAc has been proposed as a treatment for autoimmune diseases. The DFT/B3LYP/6–311++G (d,p) method as well as QTAIM and NBO analyses were used to the acidity values of D-GlcN and GlcNAc sugars and their complexes with alkali ions in the gas phase. The Li+, Na+ and K+ prefer bi-dentate chelate in these complexes. The computed results indicate that metal ion affinity (MIA) in GlcNAc is higher than that in D-GlcN. There are direct correlations between the MIA... 

    On the formation of SWCNTs and MWCNTs by arc-discharge in aqueous solutions: The role of iron charge and counter ions

    , Article Fullerenes Nanotubes and Carbon Nanostructures ; Volume 19, Issue 4 , 2011 , Pages 317-328 ; 1536383X (ISSN) Gheytani, S ; Shervin, S. H ; Simchi, A ; Sharif University of Technology
    Single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) were synthesized in aqueous solutions containing FeCl2, FeCl3, FeSO4 and Fe2(SO4) 3. The effects of iron charge and the counter ions on the formation of carbon nanotubes (CNTs) were investigated. Thermogravimetric (TG) analysis indicated that carbon multilayer structures including CNTs and multishell graphite particles were formed in deionized (DI) water without the iron precursor. SWCNTs were also synthesized in the presence of the iron ions. It was also found that the mole ratio of [Fe2+]/[Fe3+] in the solution has a significant influence on the purity of CNTs and the process yield. The highest yield was... 

    A practical scheme to involve degradation cost of lithium-ion batteries in Vehicle-to-Grid applications

    , Article IEEE Transactions on Sustainable Energy ; Volume 7, Issue 4 , Volume 7, Issue 4 , 2016 , Pages 1730-1738 ; 19493029 (ISSN) Farzin, H ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc 
    This paper concentrates on degradation of electric vehicle (EV) lithium-ion batteries in vehicle-to-grid (V2G) programs and proposes a practical wear cost model for EVs charge scheduling applications. As the first step, all the factors affecting the cycle life of lithium-ion batteries are identified and their impacts on degradation process are investigated. Subsequently, a general model for battery loss of cycle life is devised incorporating all the pertinent factors associated with charging and discharging activities in V2G applications. Modeling the battery wear cost as a series of equal-payments over the cycle life, a mechanism for calculating the cost incurred by EV users due to... 

    Ion-pair extraction-reaction of calcium using Y-shaped microfluidic junctions: An optimized separation approach

    , Article Chemical Engineering Journal ; Volume 334 , 2018 , Pages 2603-2615 ; 13858947 (ISSN) Foroozan Jahromi, P ; Karimi Sabet, J ; Amini, Y ; Sharif University of Technology
    Elsevier B.V  2018
    In this research, a continuous microsolvent extraction-reaction was developed for the efficient separation of calcium ion. This study gives a preliminary possible practical application of microfluidic devices in chemical exchange reaction for enrichment of 48Ca stable isotope. For this purpose, in the first stage, the hydrodynamic behavior of two immiscible liquids in a simple Y-shaped microfluidic junction is experimentally investigated, and then ion-pair extraction-reaction of Ca2+ using picric acid as a counter-ion and dicyclohexano-18-crown-6 (DC18C6) as a lipophilic ionophore is studied in this microfluidic and conventional batch method. The impact of main process parameters, including... 

    Study on modification of colloidal silica surface with magnesium ions

    , Article Journal of Colloid and Interface Science ; 2009 , Pages 379-383 ; 00219797 (ISSN) Karami, A ; Sharif University of Technology
    The prepared colloidal silica via ion exchange was modified by adding Mg+2 ions in the surface growth process of colloidal silica. The particle size of the modified colloidal silica was decreased by increasing the seed concentration, whereas that of colloidal silica was slightly increased as the seeds concentration exceed 15 wt%. But the trend of changes in surface area was completely reversed. Magnesium ions on surface of the modified colloidal silica were identified by the measurement of energy-dispersive X-ray spectrometry (EDS). After modifying with Mg+2 ions, the iso-electric point (IEP) of colloidal silica in pH ∼ 2 without modification, disappears over the whole pH range. © 2008... 

    Synthesis of Luminescent Carbon Dots for Selectivity Study Towards Metal Ions

    , M.Sc. Thesis Sharif University of Technology Ghasemi, Nazer Hossein (Author) ; Hormozi-Nezhad, Mohammad Reza (Supervisor)
    Today, the use of graphene quantum dots has been very much considered due to easy synthesis methods, strong fluorescence emission, and many sources of synthesis. In this study, the effect of changing capping agent of graphene quantum dots toward iron (Ⅲ), copper (Ⅱ) and mercury (Ⅱ) ions was studied. The linear range of response of the graphene quantum dots synthesized with ethylenediamine for mercury (Ⅱ) and iron (Ⅲ) ions was 10-70 µM, and this sensor also responded to Cu (Ⅱ) ions. Urea synthesized graphene quantum dots also responded to all three ions. The linear range of the response for mercury (Ⅱ) , iron (Ⅲ) and copper (Ⅱ) ions was 5-25, 10-70 and 120-120 μM respectively. The linear... 

    Prediction of the aqueous solubility of BaSO4 using pitzer ion interaction model and LSSVM algorithm

    , Article Fluid Phase Equilibria ; Vol. 374, issue , July , 2014 , p. 48-62 ; ISSN: 03783812 Safari, H ; Shokrollahi, A ; Jamialahmadi, M ; Ghazanfari, M. H ; Bahadori, A ; Zendehboudi, S ; Sharif University of Technology
    Deposition of barium sulfate (or BaSO4) has already been recognized as a devastating problem facing process industries and oilfield operations, mainly owing to its low solubility in aqueous solutions. Predicting and also preventing the overall damage caused by BaSO4 precipitation requires a profound knowledge of its solubility under different thermodynamic conditions. The main aim of this study is to develop a solubility prediction model based on a hybrid of least squares support vector nachines (LSSVM) and coupled simulated annealing (CSA) aiming to predict the solubility of barium sulfate over wide ranges of temperature, pressure and ionic compositions. Results indicate that predictions of... 

    Purification and zymography of lipase from aspergillus Niger PTCC5010

    , Article International Journal of Engineering, Transactions B: Applications ; Volume 28, Issue 8 , 2015 , Pages 1115-1123 ; 1728-144X (ISSN) Ghamari, M ; Alemzadeh, I ; Tabatabaee Yazdi, F ; Vossoughi, M ; Varidi, M ; Sharif University of Technology
    Materials and Energy Research Center  2015
    In this study, Lipase from Aspergillus Niger after extraction of medium culture was precipitated with different percentages of acetone and purified by ion exchange chromatography using SP-Sepharose HP and Q-Sepharose HP. The process of purification of the enzyme was studied by electrophoresis and the molecular weight was detected and determined by Zymography using overlying containing phenol red and Rhodamine B. The results showed that the vast majority of lipase from this strain has been precipitated by 70% saturation acetone, and leads to the 1.67 fold the purified enzyme, with special activities 32.8 U. mg-1 and efficiency of 38.5%. Using two-phase chromatography, enzyme specific activity... 

    Synergy effects of ions, resin, and asphaltene on interfacial tension of acidic crude oil and low-high salinity brines

    , Article Fuel ; Volume 165 , 2016 , Pages 75-85 ; 00162361 (ISSN) Lashkar Bolooki, M ; Riazi, M ; Ayatollahi, S ; Zeinol Abedini Hezave, A ; Sharif University of Technology
    Elsevier Ltd 
    It is well established that the heavy oil components including asphaltenes and resins play vital roles on the interfacial tension (IFT) of acidic crude oil (ACO) and aqueous solutions. Therefore, this experimental work is designed to investigate the possible synergism between salt ions, resin, and asphaltene on the IFT of ACO/low and high salinity brines containing MgCl2/NaCl and CaCl2. The results demonstrate that a complex ion of MgCl2 - resin component created in the solution could occupy the sites at the interface at high MgCl2 concentration. However, the results show that on the contrary, the molecular arrangement of MgCl2 and asphaltene at low and high MgCl2 concentration could be... 

    Electrical conductivity of methylimidazolium hexafluorophosphate ionic liquid in the presence of colloidal silver nano particles with different sizes and temperatures

    , Article Journal of Physical Chemistry C ; Volume 121, Issue 39 , 2017 ; 19327447 (ISSN) Taherkhani, F ; Kiani, S ; Sharif University of Technology
    American Chemical Society  2017
    Colloidal nanoparticle could be used for recognition location of tumors and cancer tissue. A simulation of molecular dynamic for colloidal silver nanoparticles (Ag NPs) based on density functional theory (DFT) potential parametrization with different sizes in 1-ethyl-3-methylimidazolium hexafluorophosphate [EMim][PF6] ionic liquid was performed. Then, using Green Kubo formalism, diffusion coefficient for Ag NPs in IL and in the gas phase was calculated. We also calculated diffusion coefficients of anions and cations for pure IL and IL in the presence of different sizes of Ag NPs at different temperatures. The findings showed that the diffusion coefficient of anions and cations increases in...