Search for: acetic-acid
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    A combined model for large scale batch culture MFC-digester with various wastewaters through different populations

    , Article Bioelectrochemistry ; Volume 106 , December , 2015 , Pages 298-307 ; 15675394 (ISSN) Karimi Alavijeh, M ; Yaghmaei, S ; Mardanpour, M. M ; Sharif University of Technology
    Elsevier  2015
    In this study, a new model of microbial fuel cell (MFC) was obtained for the first time. The modeled MFC was made using a combination of two approaches; the conduction-based method and two-step anaerobic digestion. Performance of the MFC was based on calculations for current evolution and polarization curves with different subsequent variables of the biofilm and anolyte. The model was able to make predictions for performance of the MFC for a simple substrate to more complex ones. The model was successfully validated with a variety of substrates (acetate, glucose and dairy wastewater) and the results were compared with previously published measurements. The model polarization results showed... 

    Effect of various carbon sources on biomass and lipid production of Chlorella vulgaris during nutrient sufficient and nitrogen starvation conditions

    , Article Bioresource Technology ; Volume 180 , 2015 , Pages 311-317 ; 09608524 (ISSN) Abedini Najafabadi, H ; Malekzadeh, M ; Jalilian, F ; Vossoughi, M ; Pazuki, G ; Sharif University of Technology
    In this research, a two-stage process consisting of cultivation in nutrient rich and nitrogen starvation conditions was employed to enhance lipid production in Chlorella vulgaris algal biomass. The effect of supplying different organic and inorganic carbon sources on cultivation behavior was investigated. During nutrient sufficient condition (stage I), the highest biomass productivity of 0.158. ±. 0.011. g/L/d was achieved by using sodium bicarbonate followed by 0.130. ±. 0.013, 0.111. ±. 0.005 and 0.098. ±. 0.003. g/L/d for sodium acetate, carbon dioxide and molasses, respectively. Cultivation under nitrogen starvation process (stage II) indicated that the lipid and fatty acid content... 

    Optimisation of a microwave-assisted method for extracting withaferin A from Withania somnifera Dunal. using central composite design

    , Article Phytochemical Analysis ; Volume 21, Issue 6 , 2010 , Pages 544-549 ; 09580344 (ISSN) Mirzajani, F ; Ghassempour, A ; Jalali-Heravi, M ; Mirjalili, M. H ; Sharif University of Technology
    Introduction - Recently, there have been growing attention on the modification and optimisation of new extraction and quantification methods, caused by the lack of environmentally friendly methodologies for the extraction of phytochemicals from complex matrices. In the case of pharmaceutical compounds, not only the extraction procedure but also the analysis method should be efficient, precise, fast and easy.Objectives - The essential pharmaceutical characteristics and trace concentration of withanolides led us to modify and optimise the previously reported extraction and quantification procedure for withaferin A (WA) as a candidate for withanolides.Matrial and methods - The WA from the... 

    Mass-transfer enhancement in single drop extraction in the presence of magnetic nanoparticles and magnetic field

    , Article AIChE Journal ; Volume 62, Issue 12 , 2016 , Pages 4466-4479 ; 00011541 (ISSN) Vahedi, A ; Molaei Dehkordi, A ; Fadaei, F ; Sharif University of Technology
    John Wiley and Sons Inc  2016
    Magnetite nanoparticles with an average particle size of 28.8 nm were synthesized, coated with oleic acid, and characterized using various techniques such as DLS, FT-IR, SEM, XRD, VSM, and UV-Vis analysis. A nanofluid consisting of synthesized nanoparticles and 5 wt % acetic acid in toluene as the dispersed phase was prepared and used in the chemical test system, Toluene-Acetic Acid-Water, for the single drop extraction in the presence and absence of an external oscillating magnetic field. Influences of various operating and design parameters such as nanoparticle concentration, drop diameter, and the applied current and frequency on the overall mass-transfer coefficients for the... 

    Fuzzy C-means clustering for chromatographic fingerprints analysis: A gas chromatography-mass spectrometry case study

    , Article Journal of Chromatography A ; Volume 1438 , 2016 , Pages 236-243 ; 00219673 (ISSN) Parastar, H ; Bazrafshan, A ; Sharif University of Technology
    Fuzzy C-means clustering (FCM) is proposed as a promising method for the clustering of chromatographic fingerprints of complex samples, such as essential oils. As an example, secondary metabolites of 14 citrus leaves samples are extracted and analyzed by gas chromatography-mass spectrometry (GC-MS). The obtained chromatographic fingerprints are divided to desired number of chromatographic regions. Owing to the fact that chromatographic problems, such as elution time shift and peak overlap can significantly affect the clustering results, therefore, each chromatographic region is analyzed using multivariate curve resolution-alternating least squares (MCR-ALS) to address these problems. Then,... 

    Liquid-Liquid equilibrium data, density, viscosity, and interfacial tension of ternary system (Toluene-Acetic Acid-Water) at 298.15 K: Experiment and correlation

    , Article Journal of Chemical and Engineering Data ; Volume 62, Issue 12 , 2017 , Pages 4133-4143 ; 00219568 (ISSN) Memari, M ; Molaei Dehkordi, A ; Seifkordi, A. A ; Sharif University of Technology
    Liquid-liquid equilibrium (LLE) data, density, viscosity, and interfacial tension for the ternary system of toluene-acetic acid-water were measured at 298.15 K and 101.7 kPa. The Othmer-Tobias and the Hand correlations were used to check the reliability of the experimental tie-lines. Moreover, the distribution coefficient and the separation factor were explored. It was found from the experimental results that a maximum separation factor value happens at an acetic acid mass fraction of 0.02 in the organic phase. Density, viscosity, and interfacial tension were correlated using the appropriate correlations such that the predicted results have excellent agreement with the experimental data. The... 

    NMR spectroscopy-based metabolomic study of serum in sulfur mustard exposed patients with lung disease

    , Article Biomarkers ; Volume 22, Issue 5 , 2017 , Pages 413-419 ; 1354750X (ISSN) Nobakht, B.F., M. Gh ; Arefi Oskouie, A ; Rezaei Tavirani, M ; Aliannejad, R ; Taheri, S ; Fathi, F ; Naseri, M. T ; Sharif University of Technology
    Taylor and Francis Ltd  2017
    Sulfur mustard (SM) is a vesication chemical warfare agent for which there is currently no antidote. Despite years of research, there is no common consensus about the pathophysiological basis of chronic pulmonary disease caused by this chemical warfare agent. In this study, we combined chemometric techniques with nuclear magnetic resonance (NMR) spectroscopy to explore the metabolic profile of sera from SM-exposed patients. A total of 29 serum samples obtained from 17 SM-injured patients, and 12 healthy controls were analyzed by Random Forest. Increased concentrations of seven amino acids, glycerol, dimethylamine, ketone bodies, lactate, acetate, citrulline and creatine together with the... 

    Synthesis and characterization of polyamide membrane for the separation of acetic acid from water using RO process

    , Article Membrane Water Treatment ; Volume 8, Issue 4 , 2017 , Pages 323-336 ; 20058624 (ISSN) Mirfarah, H ; Mousavi, S. A ; Mortazavi, S. S ; Sadeghi, M ; Bastani, D ; Sharif University of Technology
    Techno Press  2017
    The main challenge in many applications of acetic acid is acid dehydration and its recovery from wastewater streams. Therefore, the performance of polyamide thin film composite is evaluated to separate acetic acid from water. To reach this goal, the formation of polyamide layer on polysulfone support membrane was investigated via interfacial polymerization (IP) of meta-phenylenediamine (MPD) in water with trimesoyl chloride (TMC) in hexane. Also, the effect of synthesis conditions, such as concentration of monomers and curing temperature on separation of acetic acid from water were investigated by reverse osmosis process. Moreover, the separation mechanism was discussed. The solute... 

    Investigation the effect of super hydrophobic titania nanoparticles on the mass transfer performance of single drop liquid-liquid extraction process

    , Article Separation and Purification Technology ; Volume 176 , 2017 , Pages 107-119 ; 13835866 (ISSN) Hatami, A ; Bastani, D ; Najafi, F ; Sharif University of Technology
    Hydrophobic titania nanoparticles were synthesized by a novel in situ sol-gel method and applied in a single drop liquid-liquid extraction column to enhance the overall dispersed-phase mass transfer coefficient (Kod). The chemical system of toluene, acetic acid and water was used, and the direction of solute (acetic acid) mass transfer was from dispersed phase, including: toluene and acetic acid to the continuous phase of water. For such system, much of the mass transfer resistance exists in the dispersed phase, which is nonpolar organic liquid. Hence, modified titania nanoparticles (MTNP's), prepared by sol-gel route, in five different concentrations of 0.001–0.005 wt.% were added in the... 

    Ternary composite of TiO2 nanotubes/Ti plates modified by g-C3N4 and SnO2 with enhanced photocatalytic activity for enhancing antibacterial and photocatalytic activity

    , Article Journal of Photochemistry and Photobiology B: Biology ; Volume 178 , 2018 , Pages 124-132 ; 10111344 (ISSN) Faraji, M ; Mohaghegh, N ; Abedini, A ; Sharif University of Technology
    Elsevier B.V  2018
    A series of g-C3N4-SnO2/TiO2 nanotubes/Ti plates were fabricated via simple dipping of TiO2 nanotubes/Ti in a solution containing SnCl2 and g-C3N4 nanosheets and finally annealing of the plates. Synthesized plates were characterized by various techniques. The SEM analysis revealed that the g-C3N4-SnO2 nanosheets with high physical stability have been successfully deposited onto the surface of TiO2 nanotubes/Ti plate. Photocatalytic activity was investigated using two probe chemical reactions: oxidative decomposition of acetic acid and oxidation of 2-propanol under irradiation. Antibacterial activities for Escherichia coli (E. coli) bacteria were also investigated in dark and under UV/Vis... 

    New organic dyes with diphenylamine core for dye-sensitized solar cells

    , Article Journal of Materials Science: Materials in Electronics ; Volume 29, Issue 8 , April , 2018 , Pages 6323-6336 ; 09574522 (ISSN) Salimi Beni, A. R ; Karami, M ; Hosseinzadeh, B ; Ghahary, R ; Sharif University of Technology
    Springer New York LLC  2018
    In the current investigation, four novel donoracceptor type organic dyes including (DPA-Ba, DPA-Hy, DPA-Rh, DPA-Cy), are proposed and their photophysical and electrochemical properties as well as dye-sensitized solar cell performance are systematically investigated. Among these dyes diphenylamine is utilized as an-electron donor while barbituric acid, hydantoin, rhodanine-n-acetic acid and cyano acetic acid, are proposed as anchoring groups as dye-sensitized solar cells (DSSCs). The synthesized dyes are characterized using FT-IR, NMR, mass spectrometry, absorbance and electrochemical measurements. The photophysical, electrochemical and photovoltaic properties of the solar cells based on... 

    Metabolomics diagnostic approach to mustard airway diseases: A preliminary study

    , Article Iranian Journal of Basic Medical Sciences ; Volume 21, Issue 1 , 2018 , Pages 59-69 ; 20083866 (ISSN) Nobakht Mothlagh Ghoochani, B. F ; Aliannejad, R ; Oskouie, A. A ; Tavirani, M. R ; Kalantari, S ; Naseri, M. T ; Baghban, A. A ; Parastar, H ; Aliakbarzadeh, G ; Sharif University of Technology
    Mashhad University of Medical Sciences  2018
    Objective(s): This study aims to evaluate combined proton nuclear magnetic resonance (1H NMR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) metabolic profiling approaches, for discriminating between mustard airway diseases (MADs) and healthy controls and for providing biochemical information on this disease. Materials and Methods: In the present study, analysis of serum samples collected from 17 MAD subjects and 12 healthy controls was performed using NMR. Of these subjects, 14 (8 patients and 6 controls) were analyzed by GC-MS. Then, their spectral profiles were subjected to principal component analysis (PCA) and orthogonal partial least squares regression discriminant... 

    Oxidative desulfurization of Non-hydrotreated kerosene using hydrogen peroxide and acetic acid

    , Article Chinese Journal of Chemical Engineering ; Volume 17, Issue 5 , 2009 , Pages 869-874 ; 10049541 (ISSN) Molaei Dehkordi, A ; Sobati, M. A ; Nazem, M. A ; Sharif University of Technology
    The oxidative desulfurization of a real refinery feedstock (i.e., non-hydrotreated kerosene with total sulfur mass content of 0.16%) with a mixture of hydrogen peroxide and acetic acid was studied. The influences of various operating parameters including reaction temperature (T), acid to sulfur molar ratio (nacid/nS), and oxidant to sulfur molar ratio (nO/nS) on the sulfur removal of kerosene were investigated. The results revealed that an increase in the reaction temperature (T) and nacid/nS enhances the sulfur removal. Moreover, there is an optimum nO/nS related to the reaction temperature and the best sulfur removal could be obtained at nO/nS8 and 23 for the reaction temperatures of 25... 

    Generic extraction medium: From highly polar to non-polar simultaneous determination

    , Article Analytica Chimica Acta ; Volume 1066 , 2019 , Pages 1-12 ; 00032670 (ISSN) Zeinali, S ; Khalilzadeh, M ; Bagheri, H ; Sharif University of Technology
    Elsevier B.V  2019
    Sample preparation for non-target analysis is challenging due to the difficulty in the extraction of polar and non-polar analytes simultaneously. Most commercial solid sorbents lack the proper comprehensiveness for extraction of analytes with different physiochemical properties. A possible key is the combination of hydrophobic polymer and hydrophilic surface functional groups in solid based extraction methods in order to generate the susceptibility for retaining both polar and non-polar analytes. To pursue this goal, in this study, four polar groups including [sbnd]NH 2 , [sbnd]NO 2 , [sbnd]COOH, and [sbnd]COCH 3 were chemically bound to Amberlite XAD-4 substrate in order to prepare a... 

    Investigation of the impact of synthesized hydrophobic magnetite nanoparticles on mass transfer and hydrodynamics of stagnant and stirred liquid–liquid extraction systems

    , Article Chemical Engineering Research and Design ; Volume 147 , 2019 , Pages 305-318 ; 02638762 (ISSN) Hatami, A ; Azizi, Z ; Bastani, D ; Sharif University of Technology
    Institution of Chemical Engineers  2019
    The impact of modified magnetite nanoparticles (MMNPs)on hydrodynamics and mass transfer in liquid–liquid extraction process was assessed using a ternary chemical system of toluene-acetic acid–water. The organic phase which contained toluene and acetic acid was dispersed through water, and the mass transfer of acetic acid between two phases was investigated. The hydrophobic modified magnetite nanoparticles (MMNPs)prepared through an optimized in-situ method were added to the dispersed phase at different concentrations (0.001−0.005 wt%). Two separate conditions were provided in the experiments, i.e. stagnant and stirred continuous phase. The latter case was provided by a rotor at two... 

    Metabolomics analysis of the saliva in patients with chronic hepatitis b using nuclear magnetic resonance: A pilot study

    , Article Iranian Journal of Basic Medical Sciences ; Volume 22, Issue 9 , 2019 , Pages 1044-1049 ; 20083866 (ISSN) Gilany, K ; Mohamadkhani, A ; Chashmniam, S ; Shahnazari, P ; Amini, M ; Arjmand, B ; Malekzadeh, R ; Nobakht Motlagh Ghoochani, B. F ; Sharif University of Technology
    Mashhad University of Medical Sciences  2019
    Objective(s): Hepatitis B virus infection causes chronic disease such as cirrhosis and hepatocellular carcinoma. The metabolomics investigations have been demonstrated to be related to pathophysiologic mechanisms in many disorders such as hepatitis B infection. The aim of this study was to investigate the saliva metabolic profile of patients with chronic hepatitis B infection and to identify underlying mechanisms as well as potential biomarkers associated with the disease. Materials and Methods: Saliva from 16 healthy subjects and 20 patients with chronic hepatitis B virus were analyzed by nuclear magnetic resonance (NMR). Then, multivariate statistical analysis was performed to identify... 

    Simulation of methanol carbonylation reactor in acetic acid production plant: selection of an appropriate correlation for mass transfer coefficients

    , Article International Journal of Chemical Reactor Engineering ; Volume 17, Issue 4 , 2019 ; 15426580 (ISSN) Jafari, A. A ; Tourani, S ; Khorasheh, F ; Sharif University of Technology
    De Gruyter  2019
    This paper deals with mathematical modeling and simulation of methanol carbonylation reactor in acetic acid production plant that consisted of a continuous stirred tank reactor (CSTR), a flash drum, a Joule-Thomson valve, and a condenser. The model was based on material and energy balances that considered liquid-gas mass transfer, thermodynamics, and reactor hydrodynamics. The most important aspect of the model was the selection of an appropriate correlation for prediction of mass transfer coefficient. Several correlations were examined and comparison of the model results with plant data indicated that the correlation reported by Lemoine was most appropriate. The simulation results were... 

    Effect of slow biodegradable substrate addition on biofilm structure and reactor performance in two MBBRs filled with different support media

    , Article Environmental Technology (United Kingdom) ; Volume 41, Issue 21 , 2020 , Pages 2750-2759 Ashrafi, E ; Allahyari, E ; Torresi, E ; Andersen, H. R ; Sharif University of Technology
    Taylor and Francis Ltd  2020
    In this study, two moving-bed biofilm reactors (MBBR1 and MBBR2) filled with different size of carrier media (Kaldnes K1 and Kaldnes K1 micro, respectively) were subjected to soluble (sugar and sodium acetate (Ac)) substrate and mixture of soluble and particulate (particulate potato starch (PS)) substrate in a very high organic loading rate (12 kgCOD/m3·d) at different temperatures (26 and 15°C, in MBBR1 and MBBR2, respectively). The effects of carrier type and substrate on biofilm structure and reactor performance have been studied. Starch was removed by adsorption at the biofilm surface and hydrolyzed which caused substrate gradient in MBBR1, however, hydrolyzed uniformly within biofilm in... 

    Design, synthesis and application of imidazole-based organic dyes in dye sensitized solar cells

    , Article Journal of Electronic Materials ; Volume 49, Issue 6 , 2020 , Pages 3735-3750 Nabavi, S. M. J ; Alinezhad, H ; Hosseinzadeh, B ; Ghahary, R ; Tajbakhsh, M ; Sharif University of Technology
    Springer  2020
    Metal-free D–D–π–A type dyes (i.e., Car-Cy, Car-Rh, Dpa-Cy, and Dpa-Rh) were designed and synthesized for dye-sensitized solar cells (DSSCs). In the structure of the sensitized dyes, an imidazole ring is connected to a carbazole or diphenylamine moiety as a donor while cyanoacetic acid or rhodanine-3-acetic acid was introduced as an acceptor/anchor. The molecular structures of D–D–π–A type dyes were characterized using IR, NMR and MS spectral data. The optical, electrochemical, theoretical, light harvesting property, HOMO/LUMO levels, redox behavior, and photovoltaic properties of the synthesized dyes were evaluated. Among the fabricated photovoltaic devices based on the prepared dye, Dpa-Cy... 

    Self-assembly of dandelion-like hydroxyapatite nanostructures via hydrothermal method

    , Article Journal of the American Ceramic Society ; Volume 91, Issue 10 , 2008 , Pages 3292-3297 ; 00027820 (ISSN) Lak, A ; Mazloumi, M ; Mohajerani, M ; Kajbafvala, A ; Zanganeh, S ; Arami, H ; Sadrnezhaad, S. K ; Sharif University of Technology
    Self-assembled dandelion-like hydroxyapatite (HAp) nanostructures were successfully synthesized via a mild template-free hydrothermal process, using ethylenediaminetetraacetic acid (EDTA) as the surfactant. The obtained dandelion-like HAp nanostructures were between 5 and 8 μm in diameter and were composed of radially oriented nanorods with an average diameter of about 200 nm. The X-ray diffraction analysis and Fourier transform infrared spectroscopy were used to characterize the crystalline phase and purity of the synthesized nanostructures. The Brunauer-Emmett-Teller surface area of the dandelion-like nanostructures was measured to be about 39 m2/g. The results of thermal analysis revealed...