Search for: acetic-acid
Total 47 records
Oxidative Desulfurization of Gas Condensate, M.Sc. Thesis Sharif University of Technology ; Seifkordi, Ali Akbar ; Bazmi, Mansour ; Ghaedian, Maryam
Due to increasing environmental concern, special interest has been paid to reduction of organosulfur compounds in transportaion fuels. The sulfur- containing compounds are converted into sulfur oxide, i.e, SOx , during combustion, which is a major source of acid rain and air pollution.Gas condensate is a mixture consisting primarily of pentanes and heavier hydrocarbons which is recovered as a liquid from natural gas. It is a proper hydrocarbon source for producing gasoline, kerosene and gas oil in refineries. In this reseach a gas condensate was used as feedstock for studing oxidative desulfurization (ODS). The influence of various parameters of desulforization including the reaction...
Preparation a Polymeric Membrane for Dehydration of Acetic Acid, M.Sc. Thesis Sharif University of Technology ; Mousavi, Abbas ; Bastani, Dariush
The separation ofacetic acids in binary water solutions hasbeenstudied using a reverse osmosis (RO) membrane. Thin film composite polyamide membrane is used in this study.Thin-film composite (TFC) membrane was prepared through the interfacial polymerization between m-phenylenediamine (MPD) and trimesoyl chloride (TMC) on the polysulphone support membrane.The solute permeation was carried out under applied pressure of 5 bar at 25°C. In this work the effect of various synthesis conditions on the membrane performance was investigated. Parametric studies were conducted by varyingconcentration of reactants, reaction time, curing time and curing temperature. By suitable combination of these...
Characterization of Micromixing and Determination of Mass-Transfer Coefficient in a new Double-Spinning-Disk Contactor, M.Sc. Thesis Sharif University of Technology ; Molaei Dehkordi, Asghar
High mixing efficiency and high liquid-liquid mass transfer rate are two key features of spinning disk contactors. This work presents the experimental investigation of mixing and liquid-liquid mass transfer characteristics in a new double coaxial spinning disks contactor. The micromixing efficiency was investigated using a standard system of competitive parallel reaction known as iodide/iodate test reaction. The influences of various operating conditions such as the rotational speed of the disks, the direction of rotation, the feed radial location, the feed distribution pattern, the distance between the disks, and the feed flow rate on the mixing quality were examined carefully. The obtained...
Kinetic Study of Carbonylation of Methanol Using Homogenous Iridium Catalyst, M.Sc. Thesis Sharif University of Technology ; Kazemeini, Mohammad ; Mhammad Rezaee, Alireza
Homogenous carbonylation of methanol is a major way to acetic acid. In this study central composite design (CCD) at five level (-1.63, -1, 0, +1, +1.63) combined with response surface methodology (RSM) have been applied to optimize carbonylation of methanol using ruthenium promoted iridium catalyst in homogenous phase. The effect of seven process variables including; temperature, pressure, iridium, ruthenium, methyl iodide, methyl acetate and water concentrations as well as, their interactions were modeled. The determined R2 values greater than 0.9 for the rate, methane, carbon dioxide and hydrogen formation data, confirmed quadratic equation properly fitted obtained experimental data. The...
Generic extraction medium: From highly polar to non-polar simultaneous determination, Article Analytica Chimica Acta ; Volume 1066 , 2019 , Pages 1-12 ; 00032670 (ISSN) ; 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...
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) ; 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...
Column and batch study of haloacetic acids adsorption onto granular activated carbon, Article Research Journal of Chemistry and Environment ; Volume 15, Issue 2 , Jun , 2011 , Pages 866-872 ; 09720626 (ISSN) ; Mousavi, S. M ; Soltanieh, M ; Seif, K. A. K ; Sharif University of Technology
The granular activated carbon (GAC) was used as an adsorbent for its ability to remove haloacetic acids (HAAs) from drinking water by batch and column experiments. Various thermodynamic parameters, such as ΔG°, ΔH° and ΔS° have been calculated. The thermodynamics of HAAs onto GAC system indicates spontaneous and exothermic nature of the process. The ability of GAC to adsorb HAAs in a fixed bed column was investigated as well. The effect of operating parameters such as flow rate and inlet HAAs concentration on the sorption characteristics of GAC was investigated. The total adsorbed quantities, equilibrium uptakes and total removal percents of HAAs related to the effluent volumes were...
Effect of hydrogen bonds on pK a values: Importance of networking, Article Journal of the American Chemical Society ; Volume 134, Issue 25 , 2012 , Pages 10646-10650 ; 00027863 (ISSN) ; Abedin, A ; Fattahi, A ; Kass, S. R ; Sharif University of Technology
The pK a of an acyclic aliphatic heptaol ((HOCH 2CH 2CH(OH)CH 2) 3COH) was measured in DMSO, and its gas-phase acidity is reported as well. This tertiary alcohol was found to be 10 21 times more acidic than tert-butyl alcohol in DMSO and an order of magnitude more acidic than acetic acid (i.e., pK a = 11.4 vs 12.3). This can be attributed to a 21.9 kcal mol -1 stabilization of the charged oxygen center in the conjugate base by three hydrogen bonds and another 6.3 kcal mol -1 stabilization resulting from an additional three hydrogen bonds between the uncharged primary and secondary hydroxyl groups. Charge delocalization by both the first and second solvation shells may be used to facilitate...
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) ; 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...
Dna-Rna hybrid (R-loop): From a unified picture of the mammalian telomere to the genome-wide profile, Article Cells ; Volume 10, Issue 6 , 2021 ; 20734409 (ISSN) ; Sharifi Zarchi, A ; Kianmehr, L ; Sharif University of Technology
Local three-stranded DNA/RNA hybrid regions of genomes (R-loops) have been detected either by binding of a monoclonal antibody (DRIP assay) or by enzymatic recognition by RNaseH. Such a structure has been postulated for mouse and human telomeres, clearly suggested by the identification of the complementary RNA Telomeric repeat-containing RNA “TERRA”. However, the tremendous disparity in the information obtained with antibody-based technology drove us to investigate a new strategy. Based on the observation that DNA/RNA hybrids in a triplex complex genome co-purify with the double-stranded chromosomal DNA fraction, we developed a direct preparative approach from total protein-free cellular...
A cheap, simple, and versatile method for acetylation of alcohols and phenols and selective deprotection of aromatic acetates under solvent-free condition, Article Synthetic Communications ; Volume 35, Issue 3 , 2005 , Pages 483-491 ; 00397911 (ISSN) ; Saidi, M. R ; Sharif University of Technology
Acyclic and cyclic acetates of various alcohols and phenols were obtained in excellent yields under mild reaction conditions in the presence of a catalytic amount of sodium hydroxide under solvent-free conditions and microwave irradiation. Selective deprotection of acetate group from the corresponding phenolic compounds was carried out in the presence of LiClO4· 2H2O. Copyright © Taylor & Francis, Inc
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) ; 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,...
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) ; 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...
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) ; 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...
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 ; Alinezhad, H ; Hosseinzadeh, B ; Ghahary, R ; Tajbakhsh, M ; Sharif University of Technology
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...
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) ; 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...
The stereoselective synthesis of tetrahydrothiopyrano[2,3-b]indole skeletons via tandem reaction of indoline-2-thiones to Baylis-Hillman adduct acetates, Article Tetrahedron ; Volume 69, Issue 38 , September , 2013 , Pages 8169-8173 ; 00404020 (ISSN) ; Foroushani, B. K ; Sobhani, M ; Masoud, N ; Khodabakhshi, M. R ; Weng, N. S ; Sharif University of Technology
Indoline-2-thiones (5) were applied as 1,3-dinucleophiles in a tandem reaction with Baylis-Hillman adduct acetates (4) to give novel tetrahydrothiopyrano[2,3-b]indole skeletons (6). The effect of different solvents, bases, and catalysts on the yields and stereochemical outcome was studied in detail. The results indicated that acetonitrile as solvent and K 2CO3 as base, under reflux conditions, were the optimum conditions. Products 6a-6l were obtained in high diastereoselectivity and yield (up to 94%)
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) ; 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...
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) ; 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...
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) ; 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...