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    Developing a mathematical model for Ibuprofen's controlled release accounting for solubility and diffusion effects

    , Article Computer Aided Chemical Engineering ; Volume 26 , 2009 , Pages 737-742 ; 15707946 (ISSN); 9780444534330 (ISBN) Vafajoo, L ; Kazemeini, M ; Baroodi, P ; Jezowski J ; Thullie J ; Sharif University of Technology
    2009
    Abstract
    In this research a mathematical model for controlled drug delivery of Ibuprofen has been developed which accounts for physical kinetics based upon variations of the drug concentration, size and release time for a spherical drug pill. Through this model, the drug release for three sizes of the active ingredient including; 213nm (representing existence of only diffusion limitations), 515nm (representing existence of only solubility limitations) and 367nm (representing both diffusion and solubility limitations) was calculated. Theoretical amounts of the drug after two hours of release are calculated to be 95.3, 99.5 and 95.5 percent, respectively. Comparison of theoretical and experimental data... 

    Comparison of ozonation and aeration methods in removal of naphthalene from aqueous solution

    , Article Asian Journal of Chemistry ; Volume 25, Issue 16 , 2013 , Pages 9135-9137 ; 09707077 (ISSN) Derikvand, E ; Borghei, S. M ; Hassani, A. H ; Mirbagheri, S. A ; Javid, A. H ; Sharif University of Technology
    2013
    Abstract
    High molecular mass of naphthalene make it non-biodegradable and the biological methods for treated the pollutant are much time consuming. In this paper, two methods of ozonation and aeration are used to remove naphthalene. Because of the industrial wastewater has a great range of pH, in this study different concentrations of soluble naphthalene are placed in variable pH conditions, different contact times and changes in amount of aeration and ozonation. ANOVA results indicated a significant difference between two methods. The average removal of naphthalene by use of ozonation is 55 % and 37 % for aeration. As results, the best conditions that naphthalene are removed is in acidic environment... 

    Oil-soluble drag-reducing polymers [electronic resource]

    , Article Journal of polymer materials ; December 1994, Volume 11, Number 4; Page(s) 239 To 247 Zohurian Mehr, M. J. (Mohammad Jalal) ; Pourjavadi, A ; Nadali, M ; Sharif University of Technology
    Abstract
    This article reviews the oil-soluble polymeric drag-reducing agents (DRAs) with an outlook to their large-scale application in petroleum industry. A general discussion on mechanism of the DR phenomenon and mechanical degradation of the drag reducers in turbulent flow is offered with an emphasis on the molecular parameters. Furthermore, low charge density associating polymers, as a new class of oil-soluble flow improvers, are described  

    Natural gas sweetening using ionic liquids, experiment and modeling

    , Article CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES, 25 August 2012 through 29 August 2012 ; August , 2012 Safavi, M ; Ghotbi, C ; Jalili, A. H ; Taghikhani, V ; Sharif University of Technology
    2012
    Abstract
    A discussion covers the general descriptions and basic properties of ionic liquids (IL); main application areas, e.g., solvent replacement, purification of gases, homogenous and heterogeneous catalysis, biological reactions media, and removal of metal ions; and results of the research and works relating to gas solubility measurement and thermodynamic modeling of gas solubility with focus on acid gas solubility in IL. This is an abstract of a paper presented at the CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (Prague, Czech Republic... 

    Solubility of H2S in 1-(2-hydroxyethyl)-3-methylimidazolium ionic liquids with different anions

    , Article Fluid Phase Equilibria ; Volume 298, Issue 2 , November , 2010 , Pages 303-309 ; 03783812 (ISSN) Sakhaeinia, H ; Taghikhani, V ; Jalili, A. H ; Mehdizadeh, A ; Safekordi, A. A ; Sharif University of Technology
    2010
    Abstract
    The solubility of hydrogen sulfide in a series of 1-(2-hydroxyethyl)-3-methylimidazolium ([HOemim]+)-based ionic liquids (ILs) containing different anions, viz. hexafluorophosphate ([PF6]-), trifluoromethanesulfonate ([OTf]-), and bis-(trifluoromethyl)sulfonylimide ([Tf2N]-) at temperatures ranging from 303.15 to 353.15K and pressures of up to about 1.8MPa was measured by a volumetric based static apparatus. The solubility data were correlated using two models: (1) the Krichevsky-Kasarnovsky equation and (2) the extended Henry's law combined with the Pitzer's virial expansion for the excess Gibbs energy. Henry's law constants (at zero pressure) in mole-fraction and molality scales were... 

    Solubility of CO2 in 1-(2-hydroxyethyl)-3-methylimidazolium ionic liquids with different anions

    , Article Journal of Chemical Thermodynamics ; Volume 42, Issue 6 , June , 2010 , Pages 787-791 ; 00219614 (ISSN) Jalili, A. H ; Mehdizadeh, A ; Shokouhi, M ; Sakhaeinia, H ; Taghikhani, V ; Sharif University of Technology
    2010
    Abstract
    The solubility of carbon dioxide in a series of 1-(2-hydroxyethyl)-3-methylimidazolium ([hemim]+) based ionic liquids (ILs) with different anions, viz. hexafluorophosphate ([PF6]-), trifluoromethanesulfonate ([OTf]-), and bis-(trifluoromethyl)sulfonylimide ([Tf2N]-) at temperatures ranging from 303.15 K to 353.15 K and pressures up to 1.3 MPa were determined. The solubility data were correlated using the Krichevsky-Kasarnovsky equation and Henry's law constants were obtained at different temperatures. Using the solubility data, the partial molar thermodynamic functions of solution such as Gibbs free energy, enthalpy, and entropy were calculated. Comparison showed that the solubility of CO2... 

    Model study on the kinetics of scale removal due to ultrasonic radiation

    , Article 73rd European Association of Geoscientists and Engineers Conference and Exhibition 2011: Unconventional Resources and the Role of Technology. Incorporating SPE EUROPEC 2011 ; Volume 7 , 2011 , Pages 5657-5659 ; 9781617829666 (ISBN) Sherafati, M ; Hemmati, N ; Mashayekhi, L ; Sharif University of Technology
    Abstract
    Scale formation is one of the major problems in oilfields. Removal of scales is a difficult process due to their relative hardness and low solubility. Therefore it is valuable to find a method which can remove damages caused by scales. Ultrasonic radiation is known have the sufficient energy to remove the scales. Our purpose is to investigate the role of ultrasound on permeability increments due to scale removal. Some experiments were carried out to find these effects and observed that ultrasound has increased volumetric mass transfer, concentration and solubility limits. We also worked on a model presented by Tahmasebi et. al[2010] and applied changes on it to make it able to predict... 

    Rigorous modeling of gypsum solubility in Na-Ca-Mg-Fe-Al-H-Cl-H2O system at elevated temperatures

    , Article Neural Computing and Applications ; Volume 25, Issue 3 , September , 2014 , pp 955-965 ; ISSN: 09410643 Safari, H ; Gharagheizi, F ; Lemraski, A. S ; Jamialahmadi, M ; Mohammadi, A. H ; Ebrahimi, M ; Sharif University of Technology
    Abstract
    Precipitation and scaling of calcium sulfate have been known as major problems facing process industries and oilfield operations. Most scale prediction models are based on aqueous thermodynamics and solubility behavior of salts in aqueous electrolyte solutions. There is yet a huge interest in developing reliable, simple, and accurate solubility prediction models. In this study, a comprehensive model based on least-squares support vector machine (LS-SVM) is presented, which is mainly devoted to calcium sulfate dihydrate (or gypsum) solubility in aqueous solutions of mixed electrolytes covering wide temperature ranges. In this respect, an aggregate of 880 experimental data were gathered from... 

    Solubility of H2S in ionic liquids [hmim][PF6], [hmim][BF4], and [hmim][Tf2N]

    , Article Journal of Chemical Thermodynamics ; Volume 41, Issue 9 , 2009 , Pages 1052-1055 ; 00219614 (ISSN) Rahmati Rostami, M ; Ghotbi, C ; Hosseini Jenab, M ; Ahmadi, A. N ; Jalili, A. H ; Sharif University of Technology
    2009
    Abstract
    The solubility of hydrogen sulphide in three ionic liquids, viz. 1-hexyl-3-methylilmidazolium hexafluorophosphate ([hmim][PF6]), 1-hexyl-3-methylimidazolium tetrafluoroborate ([hmim][BF4]), and 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([hmim][Tf2N]), at temperatures ranging from 303.15 K to 343.15 K and pressures up to 1.1 MPa were determined. The solubility values were correlated using the Krichevsky-Kasarnovsky equation and Henry's constants were obtained at different temperatures. Partial molar thermodynamic functions of solvation such as standard Gibbs free energy, enthalpy, and entropy were calculated from the solubility results. Comparison of the values obtained... 

    Solubility calculation of oil-contaminated drill cuttings in supercritical carbon dioxide using statistical associating fluid theory (PC-SAFT)

    , Article Chemical Engineering and Technology ; Volume 31, Issue 1 , 2008 , Pages 66-70 ; 09307516 (ISSN) Esmaeilzadeh, F ; Goodarznia, I ; Daneshi, R ; Sharif University of Technology
    2008
    Abstract
    Supercritical fluid extraction is a new technology that could be effectively used to treat oil-contaminated drill cuttings generated during drilling for oil and gas. In this work, the solubility of oil-contaminated drill cuttings in supercritical carbon dioxide is obtained by an experimental flow type apparatus. The solubility was measured at 200 bar pressure, over a temperature range of 55-79.5°C. The measured solubility and experimental data for oil in drill cuttings were correlated using the PC-SAFT, PR and SRK EOS models, without any adjustable parameters. Average absolute derivations of less than 15.1 %, 98.7 %, and 99.3 % are achieved between predicted and experimental values for the... 

    Identify Cross Product Division Algebra

    , M.Sc. Thesis Sharif University of Technology Daryaei, Ali (Author) ; Mahdavi Hezavehi, Mohammad (Supervisor)
    Abstract
    In the present thesis, we study on the structure of the solvable, supersoluble, nilpotent, and irreducible structures of the subgroups. The main purpose of the present thesis is to represent a criterion given for D to be a supersoluble (nilpotent) crossed product division algebra in terms of subgroup of the multiplicative group D* of D. It is shown that the D is supersoluble (nilpotent) crossed product, if and only if D* contains an irreducible abelian-by-supersoluble (nilpotent) subgroup. Furtetmore, we review and discuss the structure of the crossed product division algebra, D, with the solvable irreducible subgroup, D*, and finally we extend our results for the semi-cross product of the... 

    Paclitaxel/β-CD-g-PG inclusion complex: An insight into complexation thermodynamics and guest solubility

    , Article Journal of Molecular Liquids ; Volume 208 , August , 2015 , Pages 145-150 ; 01677322 (ISSN) Zarrabi, A ; Vossoughi, M ; Sharif University of Technology
    Elsevier  2015
    Abstract
    Paclitaxel as one of the most effective anticancer drugs has low aqueous solubility. This inevitably reveals its commercial formulation in Cremophor EL®/ethanol mixture. However, this formulation leads to several severe side effects such as hypersensitivity reactions, neurotoxicity and nephrotoxicity. Inclusion complexation has been introduced as a practical approach in increasing paclitaxel aqueous solubility. To this end, a hybrid nanocarrier system based on hyperbranched polyglycerol and β-cyclodextrin is designed with key components uniquely structured at nanoscale and evaluated according to medical requirements. Paclitaxel is included in the hydrophobic cavity of cyclodextrin as guest... 

    Solubility of H2S in ionic liquids 1-Ethyl-3-methylimidazolium Hexafluorophosphate ([emim][PF6]) and 1-Ethyl-3-methylimidazolium Bis(trifluoromethyl)sulfonylimide ([emim][Tf2N])

    , Article Journal of Chemical and Engineering Data ; Volume 55, Issue 12 , 2010 , Pages 5839-5845 ; 00219568 (ISSN) Sakhaeinia, H ; Jalili, A. H ; Taghikhani, V ; Safekordi, A. A ; Sharif University of Technology
    2010
    Abstract
    The solubility of hydrogen sulfide gas in ionic liquids (ILs) 1-ethyl-3-methylimidazolium hexafluorophosphate ([emim][PF6]) at temperatures from (333.15 to 363.15) K and 1-ethyl-3-methylimidazolium bis(trifluoromethyl)sulfonylimide ([emim][Tf2N]) at temperatures ranging from (303.15 to 353.15) K and pressures up to about 2.0 MPa was measured using a volumetric based static apparatus. The solubility data were correlated using two models: the Krichevsky - Kasarnovsky (KK) equation, and the extended Henry's law combined with the Pitzer's virial expansion for the excess Gibbs energy. Henry's law constants (at zero pressure) were obtained at different temperatures from the obtained experimental... 

    Soluble butyl substituted copper phthalocyanine as alternative hole-transporting material for solution processed perovskite solar cells

    , Article Electrochimica Acta ; Volume 212 , 2016 , Pages 929-933 ; 00134686 (ISSN) Sfyri, G ; Chen, Q ; Lin, Y. W ; Wang, Y. L ; Nouri, E ; Xu, Z. X ; Lianos, P ; Sharif University of Technology
    Elsevier Ltd 
    Abstract
    Copper phthalocyanine can effectively act as alternative small molecule hole transporting material in perovskite solar cells. In order to produce solution processed devices, a soluble copper phtalocyanine has been synthesized by n-butyl substitution and it was compared to commercially available tert-butyl substituted copper phthalocyanine. It was found that the configuration of the butyl chain plays a very important role in film conductivity and in the subsequent efficiency of solar cells, n-bytyl derivative being the most effective hole transporter. Such a result is due to the fact that n-butyl derivative allows better packing of the molecules in the film and stronger π-π interaction  

    Microscopic structure and solubility predictions of multifunctional solids in supercritical carbon dioxide: a molecular simulation study

    , Article Journal of Physical Chemistry B ; Volume 121, Issue 7 , 2017 , Pages 1660-1674 ; 15206106 (ISSN) Noroozi, J ; Paluch, A. S ; Sharif University of Technology
    Abstract
    Molecular dynamics simulations were employed to both estimate the solubility of nonelectrolyte solids, such as acetanilide, acetaminophen, phenacetin, methylparaben, and lidocaine, in supercritical carbon dioxide and understand the underlying molecular-level driving forces. The solubility calculations involve the estimation of the solute's limiting activity coefficient, which may be computed using conventional staged free-energy calculations. For the case of lidocaine, wherein the infinite dilution approximation is not appropriate, we demonstrate how the activity coefficient at finite concentrations may be estimated without additional effort using the dilute solution approximation and how... 

    Solubility of H2S in ionic liquids [bmim][PF6], [bmim][BF4], and [bmim][Tf2N]

    , Article Journal of Chemical and Engineering Data ; Volume 54, Issue 6 , 2009 , Pages 1844-1849 ; 00219568 (ISSN) Jalili, A. H ; Rahmati Rostami, M ; Ghotbi, C ; Hosseini Jenab, M ; Ahmadi, A. N ; Sharif University of Technology
    2009
    Abstract
    The solubility of hydrogen sulfide in three ionic liquids, 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf 2N]), at temperatures ranging from (303.15 to 343.15) K and pressures up to 1 MPa was determined. The solubility data were correlated using the Krichevsky-Kasarnovsky equation, and Henry's law constants at different temperatures were obtained. From the solubility data, the partial molar thermodynamic functions of solution such as Gibbs energy, enthalpy, and entropy were calculated. Comparison showed that the solubility of H2S in these... 

    Correlation and prediction of small to large sized pharmaceuticals solubility, and crystallization in binary and ternary mixed solvents using the UNIQUAC-SAC model

    , Article Fluid Phase Equilibria ; Volume 519 , 2020 Yousefi Seyf, J ; Asgari, M ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    The recently reported UNIversal QUAsiChemical Segment Activity coefficient (UNIQUAC-SAC) model [developed by Haghtalab and Yousefi Seyf Ind. Eng. Chem. Res. 2015, 54, 8611] provides a practical thermodynamic framework to be used in VLE, LLE, and SLE calculations. The UNIQUAC-SAC model has the advantage of being independent of area (q) and volume (r) structural parameters used in the combinatorial part. While the UNIFAC or UNIFAC-DMD could not apply to the 47% (44 of 94) of the studied molecules because of the undefined groups. Here, the numbers of solvents with identified segment numbers were extended from 82 to 130 with a slight refinement to the previous values. The model parameters... 

    Effect of the heteroatom presence in different positions of the model asphaltene structure on the self-aggregation: MD and DFT study

    , Article Journal of Molecular Liquids ; Volume 334 , 2021 ; 01677322 (ISSN) Ekramipooya, A ; Mirzaee Valadi, F ; Farisabadi, A ; Gholami, M. R ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    In this study, a series of heteroatoms including nitrogen, oxygen, and sulfur were added to different positions of the model asphaltene structure to study the effect of the heteroatom presence in the self-aggregation of the model asphaltenes. Molecular Dynamics was used to calculate Solubility Parameters, Radial Distribution Function, and Relative Solubility Parameters. Additionally, Reactivity Parameters, Electrostatic Potential, Reduced Density Gradient, and Independent Gradient Model were calculated using the Density Functional Theory to further investigate the Molecular Dynamics results. This study indicated that heteroatoms' diversity and their positions in the model asphaltene... 

    Synthesis, Characterization and Spectroscopic Studies of Novel Mono and bi Nuclear Zinc(II), Palladium(II) and Cobalt(II) Schiff Base Complexes: Reactivity and Interaction

    , Ph.D. Dissertation Sharif University of Technology Askarizadeh, Elham (Author) ; Mohammadi Boghaei, Davar (Supervisor)
    Abstract
    Due to study of reactivity and interaction of Schiff base complexes, as models of biological system such as vitamin B (B6 and B12) and enzyme (cytochtome c oxidase), some mono and binuclear Zn(II), Pd(II) and Co(II) Schiff base complexes were synthesized and characterized. As a model for vitamin B6, tridentate Schiff base ligands derived from the condensation of water soluble aldehyde with the amino acids (glycine, L-alanine, L-valine, L-leucine and L-phenylalanine) in the presence of Zn (OAc)2.2H2O give rise to the formation of five new water soluble Zn(II) complexes. The IR spectra of these complexes show that, there are prominent stretching vibration of the azomethine band (HC=N) at... 

    Increased Expression of Flagellins Recombinant Soluble form by Chemical Chaperon

    , M.Sc. Thesis Sharif University of Technology Bakhtiarvand, Bahador (Author) ; Yaghmaei, Soheila (Supervisor) ; Tarahomjoo, Shirin (Supervisor)
    Abstract
    Flagella is the organelle involved in motility of Salmonella and plays an important role in colonization of Salmonella. Flagellins is the structural subunits of flagellar filament that is known as an adjuvant. Recombinant production of flagellin of S. enteritidis is advantageous due to the removal of pathogenic microorganism from the production process and improved process safety. E.coli is an appropriate host for the expression of recombinant proteins. However, its major obstacle is the formation of inclusion bodies. Inclusion bodies are aggregated inactive proteins and the recovery of proteins in the active form from these aggregates usually has a low yield. Therefore, the objective of our...