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1
Cáceres-Alonso, Mercedes, Miguel Costas, Lina Andreoli-Ball, and Donald Patterson. "Steric effects on the self-association of branched and cyclic alcohols in inert solvents. Apparent heat capacities of secondary and tertiary alcohols in hydrocarbons." Canadian Journal of Chemistry 66, no. 4 (1988): 989–98. http://dx.doi.org/10.1139/v88-165.
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Apparent heat capacities have been measured for fifteen branched and cyclic alcohols in dilute n-decane solution at 25 °C. The alcohols were 2-methyl-2-propanol, cyclohexanol, 3-methyl-3-pentanol, trans-, cis-, and mixed isomer 2-methylcyclohexanol, 1-methylcyclohexanol, 3-ethyl-3-pentanol, cyclooctanol, 3,7-dimethyl-1-octanol, 5-decanol, 4-propyl-4-heptanol, cyclododecanol, 5-butyl-5-nonanol, and 8-hexadecanol (in n-hexane). Excess heat capacities CpE throughout the concentration range were measured at 25 °C for: 1-hexanol + n-hexadecane (n-C16) and + 2,2,4,4,6,8,8-heptamethylnonane (br-C16), 4-propyl-4-heptanol, and 1-decanol + n-decane, 3-methyl-3-pentanol + n-C16 and + br-C16 and at 27 °C for cyclohexanol + n-C16 and + br-C16. Also, for 3-methyl-3-pentanol + n-decane CpE was measured at 10, 25, 40, and 50 °C. For a series of isomeric alcohols, the apparent molar heat capacities show a maximum against concentration which decreases and moves to higher alcohol concentration as the hydroxyl group on the alcohol becomes increasingly hindered, effectively reducing the alcohol self-association capabilities. This situation is also reflected by the heat capacities of the pure alcohols which increase strongly in magnitude in going from a linear 1-alcohol to an isomeric alcohol which has its hydroxyl group on a quaternary carbon atom. CpE of the mixtures are negative at low alcohol concentrations turning positive at increasingly higher alcohol concentrations as the steric hindrance on the hydroxyl group increases. Throughout most of the concentration range CpE for the branched or cyclic alcohols is considerably more positive than for the corresponding isomeric 1 -alcohol. For the highly hindered 3-methyl-3-pentanol CpE(T) passes through a maximum. All of the above behaviour is explained by the Treszczanowicz–Kehiaian model for self-associated liquids + inert solvents which has been applied to the present data. Equilibrium constants have been obtained for alcohol association and are sensitive to alcohol structure. At low alcohol concentrations, while for the linear 1-alcohols tetramers are the predominant species and dimer are almost absent, for the corresponding isomeric alcohols the concentration of tetramers is severely reduced and the lower species, i.e. trimers and dimers, are more important. For the highly hindered alcohols, monomers are the predominant species in dilute solution reflecting the decrease in self-association ability that steric hindrance of the hydroxyl group imposes on them.
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Zuo, Xu, and Hongtao Kao. "Numerical simulation of CO2 absorption by AMP solution in structured packing with different parameter condition." Thermal Science, no. 00 (2024): 62. http://dx.doi.org/10.2298/tsci231109062z.
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The FLUENT software is utilized in this research to simulate the carbon dioxide absorption process by 2-amino-2-methyl-1-propyl alcohol through numerical simulation. A mathematical model is established to represent the mass transfer process between the 2-amino-2-methyl-1-propyl alcohol solution and carbon dioxide. Various operating parameters, such as the molar fraction of the solution, gas mass fraction, pressure, and gas flow velocity, are investigated to calculate the absorption efficiency of carbon dioxide under different conditions. The distribution of the product reveals that the 2-amino-2-methyl-1-propyl alcohol carbamate product more readily infiltrates the surface of the unit model when the gas phase velocity is relatively low. In contrast, the product 2-amino-2-methyl-1-propyl alcohol carbamate tends to accumulate in the upper half of the unit model when the gas phase velocity is relatively high. Sixteen simulation conditions are summarized to determine the optimal parameters. These optimal parameters include a 2-amino-2-methyl-1-propyl alcohol molar fraction of 0.4, atmospheric pressure, a flue gas flow velocity of 0.0737 m/s, and a carbon dioxide mass fraction of 0.12. This research serves as a valuable reference for engineering applications related to carbon dioxide absorption using 2-amino-2-methyl-1-propyl alcohol solutions, providing essential technical support in the fight against climate change.
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Korobova, O. V., L. K. Samarska, S. L. Humenjuk, et al. "STUDY OF DIAZINONE IN MODEL PREPARATIONS BASED ON METHANOL AND ISOPROPANOL BY HIGHLY EFFICIENCY LIQUID CHROMATOGRAPHY (HPLC)." Scientific and Technical Bulletin оf State Scientific Research Control Institute of Veterinary Medical Products and Fodder Additives аnd Institute of Animal Biology 22, no. 2 (2021): 163–70. http://dx.doi.org/10.36359/scivp.2021-22-2.20.
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The aim of the study was to investigate the stability of diazinon in two model mixtures in which the active substance content is 10%. Methyl and isopropyl alcohols were used as a basis for the production of model solutions with diazinon. According to the recipe of model drugs, methyl or isopropyl alcohols make up about half of the content of drug components.
 The diazinon content was determined by reversed-phase high performance liquid chromatography (HPLC) on 3, 14 and 21 days for the model mixture with methyl alcohol and on 14 and 50 days for the mixture with isopropyl alcohol.
 A significant number of publications have been devoted to the study of the degradation of diazinon and other nonspecific organophosphorus pesticides under the influence of various factors. However, it remains relevant to study this process in mixtures of a certain composition, in particular in new veterinary drugs under development. This article presents a comparison of the results of determination the content of diazinon in model mixtures based on methyl and isopropyl alcohols.
 The analyzes were performed on a Knauer liquid chromatograph with a spectrophotometric detector equipped with a Luna® Omega Polar C 18 150 × 4.6 mm column filled with a 5 μm sorbent of Phenomenex particle size with a 4 × 3.0 mm universal C 18 protective column. Mobile phase: degassed mixture of acetonitrile: water in the ratio 65:35, flow rate 1.1 ml / min at a column temperature of 20 °C, detection at a wavelength of 245 nm, injection volume - 0.050 ml, time of one separation - 20 minutes.
 It was found that the content of diazinon on the 21st day of storage of the model mixture based on methyl alcohol is about 30 % of the applied, while on the 50th day of storage of the model mixture based on isopropyl alcohol – 97 %.
 As we found in previous studies, the use of methyl alcohol is a probable factor in the breakdown of diazinon in the drug. The appearance of the peak of one of the products of diazinon for 3 min of the chromatogram of solutions of the production experimental preparation and the model mixture made in the HPLC laboratory with the solvent methanol was noted. When replacing methanol with isopropanol, the chromatogram of the drug solution did not show the appearance of an additional peak, except for the peak identified as diazinon. The use of isopropyl alcohol does not reduce the concentration of diazinon in the model mixture, as in the case of methanol. The composition with isopropyl alcohol provides relative stability of the model mixture.
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Cheng-Gen, ZHANG, LI Wen-Zuo, and HUANG Ming-Bao. "Reaction of Methyl Alcohol with Thionyl Chloride in Solution." Acta Physico-Chimica Sinica 23, no. 03 (2007): 399–403. http://dx.doi.org/10.3866/pku.whxb20070322.
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Stephenson, W. Kirk, and Richard Fuchs. "Enthalpies of interaction of hydroxylic solutes with organic solvents." Canadian Journal of Chemistry 63, no. 9 (1985): 2535–39. http://dx.doi.org/10.1139/v85-419.
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Heats of solution of m-cresol, 1-butanol, 1-pentanol, t-amyl alcohol, and model compounds (toluene, ethyl ether, n-butyl methyl ether, t-butyl methyl ether) in 17 organic solvents (n-heptane, cyclohexane, carbon tetrachloride, 1,2-dichloroethane, α,α,α-trifluorotoluene, triethylamine, butyl ether, ethyl acetate, dimethylformamide, dimethyl sulfoxide, benzene, toluene, mesitylene, t-butyl alcohol, 1-octanol, methanol, 2,2,2-trifluoroethanol) have been combined with solute heats of vaporization to give solvation enthalpies (ΔH(v → S)). Dependencies of solute vs. model solvation enthalpy differences on solvent dipolarity–polarizability and hydrogen-bond-accepting basicity were determined via correlations with Taft–Kamlet solvatochromic parameters (π*, β, ξ).m-Cresol is a substantially stronger H-bond donor than 1-butanol, 1-pentanol, and t-amyl alcohol, and H-bonds to acceptor solvents including alcohols. Cresol acts as an H-bond acceptor with the strong H-bond donor solvent trifluoroethanol.
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Ma, Fengjie, Xiaolin Pu, Bo Wang, Jia Li, and Cheng Cao. "Preparation and evaluation of polyampholyte inhibitor DAM." RSC Adv. 7, no. 78 (2017): 49320–28. http://dx.doi.org/10.1039/c7ra08385h.
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In this study, polyampholyte inhibitor DAM was synthesized from three monomers, namely, diallyl dimethyl ammonium chloride, methyl allyl alcohol and 2-acrylamido-2-methyl propane sulfonic acid, by aqueous solution polymerization.
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Minato, Jun-ichi, and Kun'ichi Miyazawa. "C60 fullerene tubes as removable templates." Journal of Materials Research 21, no. 2 (2006): 529–34. http://dx.doi.org/10.1557/jmr.2006.0066.
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Crystalline microtubes (inner diameter 240–2100 nm) consisting of C60 fullerene molecules were prepared in the mixture of C60-saturated pyridine and isopropyl alcohol kept at 0 °C. Characterization by transmission electron microscopy showed a linear relationship between the outer diameter and the inner diameter for the C60 fullerene tubes. Optical observations suggested that the specimens already had tubular structure when they were grown in the solution. Deposition of guest crystals inside the C60 fullerene tubes was performed by the following procedure: (i) ultrasonic pulverization to obtain the C60 fullerene tubes with open ends, (ii) absorption of methyl alcohol solution of KBr into the tubes by the capillary attraction, and (iii) evaporation of methyl alcohol to precipitate KBr inside the tubes. Columnar KBr crystals were then obtained by dissolving the fullerene tube walls in toluene.
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Lahooti-Fard, Farzad, Mohammad Imani, and Ali Akbar Yousefi. "Solvent-dependent rheological behavior of concentrated solutions of a cationic acrylic terpolymer containing self-assembled chains." e-Polymers 15, no. 4 (2015): 279–83. http://dx.doi.org/10.1515/epoly-2015-0057.
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AbstractIt has been proved that alcohol molecules exist as cyclic and chain aggregates of different sizes in pure or mixed solvent systems. Here, it will be shown that these aggregates can radically change the rheological properties of a concentrated polymer solution containing self-assembled chains. In a previous study by the same authors, the existence of self-assembled structures in dilute solution of poly(dimethylaminoethyl methacrylate-co-methyl methacrylate-co-butyl methacrylate) in an alcoholic solvent mixture was shown according to small angle X-ray scattering results, showing that these structure were much more compact than those in acetone. This finding is based on the role of alcohol aggregates as physical cross-linkers. Here, the existence of self-assembled structures in concentrated solutions of the same terpolymer was confirmed by atomic force microscopy and rheology results both in acetone (a good solvent) and in a solvent mixture composed of acetone, ethanol and 1-propanol. For the terpolymer solutions in the solvent mixture, very little decrease in complex viscosity and shear thickening were observed at high strains and frequencies, respectively. It can be concluded that the alcohol aggregates can cause the formation of strong self-assembled structures that can even resist high shear forces or strains.
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Umegaki, T., Y. Enomoto, and Y. Kojima. "Metallic ruthenium nanoparticles for hydrogenation of supercritical carbon dioxide." Catalysis Science & Technology 6, no. 2 (2016): 409–12. http://dx.doi.org/10.1039/c5cy00994d.
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Lihanov, V. A., and O. P. Lopatin. "The toxicity study of diesel engines working on biofuels based on methyl alcohol." Izvestiya MGTU MAMI 12, no. 3 (2018): 51–57. http://dx.doi.org/10.17816/2074-0530-66837.
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The paper substantiates the need for the use of biofuels based on methyl alcohol in diesel engines. At the same time, such environmentally friendly energy sources as methanol and methyl ether of rapeseed oil were investigated. The physical and chemical properties of these biofuels are presented. In order to develop, determine and optimize the composition of environmentally friendly biofuels for diesel engines, their tests were carried out when working on methanol with methyl ether of rapeseed oil and methanol-fuel emulsion. It was experimentally established that the use of environmentally friendly biofuels in diesel engines is possible in the form of alcohol-fuel emulsions (methyl alcohol - 25%, detergent-dispersing additive succinimide C-5A - 0.5%, water - 7%, diesel fuel - 67.5%) and in the form of a separate supply of methyl alcohol (88%) and methyl ether of rapeseed oil (12%). When using methanol as a biofuel for diesel engines, it is possible to significantly reduce the emissions of soot particles and nitrogen oxides due to the fact that during the combustion of alcohol in the combustion chamber of diesel, less intermediate products (in relation to diesel fuel) are formed, contributing to the birth of acetylene and aromatic hydrocarbons, which lead to the formation of soot. Methyl alcohol, with its simpler structure and small molecule sizes, is one of the determining factors for more “pure combustion” of fuel. Experimental studies of diesel engines on environmentally friendly biofuels of the above compositions were carried out and a promising solution to improve their environmental performance was justified. When the diesel engine is working on a methanol-fuel emulsion, the content of nitrogen oxides in the exhaust gases is reduced by 41.3%, carbon black by 85.5%, carbon dioxide by 6.7%, carbon monoxide by 45.0%; when working on methanol and methyl ether of rapeseed oil, nitrogen oxides by 47.4%, carbon black by 90.4%, carbon oxide by 44.8%.
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Agboluaje, Maryam, Ibrahim Refai, Henry H. Manston, et al. "A comparison of the solution radical propagation kinetics of partially water-miscible non-functional acrylates to acrylic acid." Polymer Chemistry 11, no. 44 (2020): 7104–14. http://dx.doi.org/10.1039/d0py01356k.
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Rai, K. M. Lokanatha, K. B. Umesha, and M. A. Harish Nayaka. "Antioxidant and Antimicrobial Activity of 5-methyl-2-(5-methyl-1,3-diphenyl-1H-pyrazole-4-carbonyl)-2,4-dihydro-pyrazol-3-one." International Journal of Biomedical Science 5, no. 4 (2009): 359–68. http://dx.doi.org/10.59566/ijbs.2009.5359.
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Cycloaddition of nitrile imines 4 generated in situ by the catalytic dehydrogenation of diphenyl hydrazones 3 using Chloramine-T (CAT) as oxidant in glacial acetic acid with enolic form of ethyl acetoacetate 5 afforded Ethyl 3-aryl-5-methyl-1-phenyl-1H-pyrazol-4-carboxylate 6 in 80% yield. The said pyrazoles 6 refluxed with 80% hydrazine hydrate using absolute alcohol as solvent for about 2-3 hours to produce the respective 5-methyl-1,3-diphenyl-1H-pyrazole-4-carboxylic acid hydrazide 7. The alcoholic solution of pyrazole acid hydrazides on heating with ethyl acetoacetate 5 to give the 5-methyl-2-(5-methyl-1,3-diphenyl-1H-pyrazole-4-carbonyl)-2,4-dihydro-pyrazol-3-one 8. The synthesized compounds were found to exhibit good antimicrobial and antioxidant activity as evaluated by 1,1-diphenyl-2-picryl Hydrazyl (DPPH) radical scavenging, reducing power and DNA protection assays.
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Soloviev, Mikhail, and Valery Makaryin. "Modelling of structure and concentration characteristics of water-alcohol solutions." From Chemistry Towards Technology Step-By-Step 4, no. 4 (2023): 100–109. http://dx.doi.org/10.52957/2782-1900-2024-4-4-100-109.
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Water-alcohol solutions are widely used in pharmacy, food industry, engineering, etc. The study of their physical and chemical properties has a long history. Nevertheless, due to the complexity of these systems, there is still an interest in their research stimulated by the development of biochemistry in terms of the study and protection of the environment, global climate change, renewable energy resources and cosmochemistry. The purpose of the presented study is the quantum-chemical investigation of water clusters with methyl and ethyl alcohol molecules, as well as the modelling of concentration dependences of the excess molar volume of ethyl alcohol solution in water at different temperatures. Based on quantum-chemical calculations of paired and mixed complexes of water with methanol and ethanol, taking into account solvation effects, study reveals the formation of thermodynamically efficient complexes in liquid, in contrast to the ideal gas state, while in the mixture both individual solvated alcohol molecules and complexes will be in equilibrium. We noted a relative difference in the free energies of solvation of paired and mixed methanol and ethanol complexes. The paper proposes a technique for calculating the excess molar volume in water-alcohol mixtures by approximating the experimental dependences by Lejandre polynomials of the ninth degree. The calculation results showed high accuracy. Hence, continuous functions describe the dependences of the calculated coefficients of Lejandre polynomials on temperature.
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Patil, Mallikarjunagouda, Shridhar N. Mathad, Arun Y. Patil, et al. "Synthesis and Characterization of Microwave-Assisted Copolymer Membranes of Poly(vinyl alcohol)-g-starch-methacrylate and Their Evaluation for Gas Transport Properties." Polymers 14, no. 2 (2022): 350. http://dx.doi.org/10.3390/polym14020350.
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Poly(vinyl alcohol) (PVA) is an excellent membrane-forming polymer and can be modified with potato starch and methyl acrylate monomers to obtain copolymers with improved physical and chemical properties. The study presents the synthesis of poly(vinyl alcohol)-g-starch-poly(methyl acrylate) PVA-g-St-g-PMA copolymers using microwave irradiation technique and potassium persulfate initiator. Solution casting and solvent evaporation methods were adopted for the fabrication of polyvinyl alcohol-g-starch-acrylamide composite membranes. The synthesized graft copolymer was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and thermal analysis. The modified nanocomposite membranes were showed very promising results with the parameters permeability and selectivity. The nanocomposite membranes exhibited the advantages of easy handling and reuse.
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Purnavita, Sari, Cyrilla Oktaviananda, Sri Sutanti, Herman Yoseph Sriyana, Antonius Prihanto, and Antonio Mafeli. "Polymerization of Poly Methyl Methacrylate Using Emulsion Method and H2O2 as Initiator." Journal of Chemical Process and Material Technology 1, no. 2 (2022): 10. http://dx.doi.org/10.36499/jcpmt.v1i2.6642.
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This study aims to study the effect of the amount of initiator (H2O2) on the viscosity of the Polymethyl Methacrylate (PMMA) emulsion and the solids content. The treatment of independent variables is H2O2 by 1%, 2%, 3%, and 4%. This research procedure was carried out in a two-stage process. The first stage is the process to separate the inhibitor contained in the methyl methacrylate monomer by adding a 1 N concentration of NaOH solution, stirring until evenly distributed, then put into a separating funnel to separate pure methyl methacrylate from the inhibitor dissolved in alkaline solution. The second stage is the polymerization reaction process using the emulsion method. Dissolve the poly vinyl alcohol in hot water at 70oC, put the poly vinyl alcohol solution into a three-neck flask, which is equipped with a stirrer and a hot plate heater, add the initiator and up to 60oC, then add the methyl methacrylate monomer with stirring and heating at room temperature 100oC for 1 hour. The resulting product is a thick poly methyl methacrylate emulsion, has a milky white color, and has good adhesion. Furthermore, the viscosity test was carried out using ford cup number 4 and the solids content test. The results showed that the more initiators added, the higher the viscosity and the higher the solids content.
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Abdullah, Abdullah, Triyono Triyono, and Bambang Setiaji. "Preparation of Peleted Ni-Pt/Zeolite for Conversion of Amyl and Isoamyl Alcohol to Hydrocarbon." Indonesian Journal of Chemistry 1, no. 2 (2010): 53–62. http://dx.doi.org/10.22146/ijc.21944.
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Catalysts with Ni and Pt as active metals in peleted zeolite were used for conversion of amyl alcohol, isoamyl alcohol and their mixture to hydrocarbon compounds. The catalysts were prepared by impregnation the peleted zeolite in NiCl2.6H2O and PtCI4 solution, while stirring for 24 hours then followed by oxidation with 02 gas at 350 °C for 2 hours and reduced by hydrogen gas at 400 °C for 1 hour. Ni and Pt in catalysts were determined by MS, specific surface area, total pore volume and gas sorption analyzer NOVA-1000 determined pore radius average. Determination of catalysts acidity was carried out by absorption of ammonia method. The activity of catalysts was evaluated in a micro reactor by flow system. Experimental temperature by varied between 300 and 400 °C with the increment of 25 °C. Products were analyzed by gas chromatographic and mass spectrometric method. The result shows that Ni-Pt/zeolite is more active than Ni/zeolite can be used for converting all of the alcohol. Products for conversion are 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, cyclopentane, 3-methyl-1-butanaldehide and acetone. The highest conversion was observed on isoamyl alcohol (31.37%) at 400 °C.
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Zhang, Wang Xi. "Characterization of Polyvinyl Alcohol-Polyaniline Blend Films." Applied Mechanics and Materials 44-47 (December 2010): 2191–94. http://dx.doi.org/10.4028/www.scientific.net/amm.44-47.2191.
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In this study a solution-blend method is adopted to prepare conductive polyvinyl alcohol (PVA) and polyaniline doped with dodecyl benzene sulfonic acid (PVA/PANI-DBSA) blend films. Emeraldine base (EB)-type polyaniline (PANI) is dissolved in N-methyl-2-pyrrolidinone (NMP) and then blended with PVA/dodecyl benzene sulfonic acid (DBSA) solution by various amounts. The morphological structures and characterized of the films were observed via scanning electronic microscopy (SEM), thermogravimetric analysis (TGA) and X-ray powder diffraction (XRD). Electrical properties of the blends were characterized by means of electrical conductivity measurements. It is found that the electrical conductivity and the thermal degradation onset temperature of the PVA/PANI-DBSA blend film are increased as the amount of PANI-DBSA is increased.
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Malikova, N. N., N. I. Alizade, and T. M. Nagiev. "CATALASE AND PEROXIDASE BIOMIMETIC SENSOR BASED ON Ag-ELECTRODE." Azerbaijan Chemical Journal, no. 4 (November 14, 2023): 40–47. http://dx.doi.org/10.32737/0005-2531-2023-4-40-47.
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Research has been carried out on the development of a biomimetic sensor of the catalase and peroxidase type to determine trace amounts of peroxide hydrogen and low concentrations of ethyl alcohol in an aqueous solution. By potentiometric research, the physicochemical feature of the catalase and peroxidase biomimetic sensor was studied, the transducer of which was Ag. Rapid and accurate determination of hydrogen peroxide is very important, but no less important side of this issue is associated with the determination of trace amounts of C2H5OH in aqueous media of various origins. The need to develop express methods for determining the concentration of C2H5OH in aqueous solutions follows from the requirements for the quality of wine and alcohol products. As you know, the taste and drinking qualities of the product depend on the ratio of methyl and ethyl alcohols. In this work, biomimetic sensors of the catalase and peroxidase types based on an Ag electrode were developed for determining trace amounts of hydrogen peroxide and ethanol. Biomimetic sensors of the catalase and peroxidase types based on an Ag electrode have been developed for the determination of microquantities of hydrogen peroxide and ethyl alcohol. The applicability of a biomimetic sensor for determining trace concentrations of hydrogen peroxide, as well as for determining microquantities of ethyl alcohol in an aqueous solution with a low detection limit, high sensitivity, wide recognition range, high stability, and repeated use, is shown. The developed and synthesized biomimetic sensor of the catalase and peroxidase types based on TPhPFe3+/Al2O3/Ag have high sensitivity, stability, and do not lose their activity for a long time
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CHERKASHINA, N. I., D. V. PUSHKARSKAYA, D. A. RYZHIKH, and R. A. LYUBUSHKIN. "INFLUENCE OF AQUEOUS AND ALCOHOL ENVIRONMENT ON THE PROCESS OF SUSPENSION POLYMERIZATION OF METHYL METHACRYLATE." Herald of Technological University 27, no. 11 (2024): 46–50. https://doi.org/10.55421/1998-7072_2024_27_11_46.
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In this work, the effect of the chemical properties of liquid media on the process of suspension polymerization of methyl methacrylate and the size of the resulting colloidal particles under the thermal effect of elevated temperatures and physical acceleration of the process are studied. The process of suspension polymerization based on methyl methacrylate is considered in an aqueous medium (H2O) and in an alcohol medium, namely, in ethyl alcohol (CH3CH2OH) under the same parameters: solution heating temperature, pressure, air humidity and ambient temperature in the laboratory. The results of measuring the dispersion of the formed colloidal particles during polymerization in each medium are presented. Every 10 min. a sample was taken from the solution for comparative analysis. The sizes of colloidal particles were determined using a Zetatrac particle size analyzer from Microtrac Inc. (Montgomeryville, Pennsylvania, USA). A comparative analysis of the monomer conversion rates in different media was carried out using the calculation method at different time intervals of the experiment. Particle size in the first 10 min. in an aqueous medium is 0.121 μm, which is 30 times larger than the size of a colloidal particle in an alcohol medium at the same time. According to the results of the study, the conversion process of methyl methacrylate monomer occurs according to three Harkinson periods, in an aqueous medium, the conversion efficiency is 8% higher than in a medium with ethyl alcohol. Also, in an aqueous medium, the rate of the process of colloidal particle formation is higher and the molecular weight of colloidal particles is higher at any time interval. The process of colloidal particle formation in an alcohol suspension occurs more smoothly. A sharp increase in molecular weight is observed after 3.5 hours from the beginning of the experiment.
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Karalkeviciene, Rasa, Eva Raudonyte-Svirbutaviciene, Justina Gaidukevic, Aleksej Zarkov та Aivaras Kareiva. "Solvothermal Synthesis of Calcium-Deficient Hydroxyapatite via Hydrolysis of α-Tricalcium Phosphate in Different Aqueous-Organic Media". Crystals 12, № 2 (2022): 253. http://dx.doi.org/10.3390/cryst12020253.
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In the present work, the effects of various organic solvents (solvent nature and fraction within the solution) and solvothermal conditions on the formation of calcium-deficient hydroxyapatite (CDHA) via hydrolysis of α-tricalcium phosphate (α-TCP) are investigated. The wet precipitation method is applied for α-TCP synthesis, and the hydrolysis reaction is performed in solutions with different water-to-organic solvent ratios under solvothermal conditions at 120 °C for 3 h and at 200 °C for 5 h. Ethyl alcohol, isopropyl alcohol, and butyl alcohol did not inhibit the hydrolysis of α-TCP, while methyl alcohol and ethylene glycol have a more prominent inhibitory effect on the hydrolysis, hence the formation of single-phased CDHA. From all the solvents analysed, ethylene glycol has the highest impact on the sample morphology. Under certain water to ethylene glycol ratios and solvothermal conditions, samples containing a significant fraction of rods are obtained. However, samples prepared with ethylene glycol are characterised by a particularly low BET surface area.
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Stanc, Yannick Le, and Maurice Le Corre. "L'o-nitrobenzylidènediméthylsulfuranne: synthèse, réactivité." Canadian Journal of Chemistry 63, no. 11 (1985): 2958–60. http://dx.doi.org/10.1139/v85-490.
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In aqueous solution, o-nitrobenzyldimethylsulfonium bromide and the corresponding ylid give, depending upon the conditions, o-nitrobenzyl alcohol, o-nitrobenzylsulfide, or methyl o-hydroxymethylbenzyl sulfide. The o-nitrophenyloxiranes may be obtained by the reaction of nitrobenzylidenedimethylsulfurane with aldehydes in a two-phase aqueous sodium hydroxide/dichloromethane system.
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Whitfield, Dennis M., M. Younus Meah, and Jiří J. Křepinský. "Ultrasonic Agitation Accelerates cis-Glycosylation with Heterogeneous Promoters." Collection of Czechoslovak Chemical Communications 58, no. 1 (1993): 159–72. http://dx.doi.org/10.1135/cccc19930159.
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Ultrasonic agitation increases the yield of glycosylations with donors such as 3,4,6-tri-O-acetyl-2-azido-2-deoxy-α-D-galactopyranosyl chloride using the heterogeneous promoters silver zeolite, cadmium zeolite or a mixture of silver perchlorate and silver carbonate on celite. The stereospecificity of the glycosylation depends on the nature of the alcohol to be glycosylated, the nature of the solid support and the solvent. Glycosylation catalyzed by silver zeolite in toluene solutions of the donor 3,4,6-tri-O-acetyl-2-deoxy-2-phtalimido-β-D-glucopyranosyl bromide, that usually produce trans-β-glycosides, yield cis-glycosides with unreactive alcohols. In these unreactive alcohols, e.g. methyl 2-O-benzoyl-4,6-O-benzilidene-β-D-galactopyranoside and benzyl 3,4,6-tri-O-benzyl-α-D-mannopyranoside, the hydroxyls to be glycosylated are hydrogen-bonded to a cis vicinal oxygen. This feature was evident in their AM1 minimized conformations and was indicated by the solution J(OH,CH) 1H NMR coupling constants.
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Chang, Hui-Yi, Chao-Ching Chang, and Liao-Ping Cheng. "Preparation of hydrophobic nanofibers by electrospinning of PMMA dissolved in 2-propanol and water." MATEC Web of Conferences 264 (2019): 03004. http://dx.doi.org/10.1051/matecconf/201926403004.
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In this study, we adopted rubbing alcohol (2-propanol/water = 7.8/2) as the solvent to prepare hydrophobic poly(methyl methacrylate) (PMMA) nanofibers (with submicron scale diameters) by electrospinning. In the literature, the general solvents, such as acetone, tetrahydrofuran, chloroform, toluene, etc., to dissolve PMMA are harmful and not environmentally friendly. 2-Propanol and water are both not hazardous to humans and the environment. PMMA dissolved in rubbing alcohol can be electrospun near room temperature. The solutions were heated at ~60 °C and allowed to cool to room temperature. Controlling the solution concentration and electrospinning parameters, fibers with diameters of 0.65~0.85 μm were obtained. The electrospun PMMA mats were hydrophobic with contact angles > 130 ° and showed good water resistance.
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BYKOV, D. S., YU V. SHULEVICH, T. P. BOGDANOVA, E. G. DUKHANINA, A. V. NAVROTSKII, and I. A. NOVAKOV. "MATRIX POLYMERIZATION OF TRIMETHYL[METHACRYLOXYETHYL]AMMONIUM METHYL SULFATE ON SODIUM DODECYL SULFATE MICELLES IN DILUTE SOLUTIONS." IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY, no. 12(295) (December 2024): 136–44. https://doi.org/10.35211/1990-5297-2024-12-295-136-144.
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The effect of dodecyl alcohol on the micelle formation of sodium dodecyl sulfate has been studied by fluorescence spectrophotometry, conductometry and tensometry, and critical concentrations of micelle formation corresponding to the formation of spherical and aspherical micelles have been determined. Polymerization of trimethyl[methacryloxyethyl]ammonium methyl sulfate on sodium dodecyl sulfate micelles containing dodecyl alcohol was carried out. The viscosimetry method determined the characteristic viscosities of synthesized polyelectrolytes. Synthesized polyelectrolytes on micelles are characterized by higher values of characteristic viscosity than polyelectrolytes obtained in aqueous solution in the absence of surfactants. The difference in the values of the characteristic viscosity is due to the effect of dodecyl alcohol on the size and shape of sodium dodecyl sulfate micelles.
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Kobayashi, Shinjiro, Qin Qin Zhu, and Wolfram Schnabel. "Reactions of Substituted Vinyl Cations in Acetonitrile Solution as Studied by Flash Photolysis." Zeitschrift für Naturforschung B 43, no. 7 (1988): 825–29. http://dx.doi.org/10.1515/znb-1988-0707.
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Vinyl cations I+, I+b, I+c of the structure R′2C=CR″ (I+a: R′ = R″ = anisyl; I+b R′ = phenyl.R″ = anisyl. I+c: R′ - methyl.R″ = anisyl) were generated by flash photolysis of corresponding bromides. Lifetime measurements yielded the following: substitution of aromatic groups in 2-position by methyl groups largely improved the electrophilicity of the vinyl cations. The nucleophilicity of typical compounds (ketone, ester, alcohol, olefin) was measured.
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Sharanda, M. E., A. M. Mylin, O. Yu Zinchenko, and V. V. Brei. "Vapor-phase oxidation of propylene glycol-methanol mixture to methyl lactate on CeO2/Al2O3 catalyst." Catalysis and Petrochemistry, no. 34 (2023): 86–91. http://dx.doi.org/10.15407/kataliz2023.34.086.
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The vapor-phase oxidation of mixtures of propylene glycol with methanol and ethanol to methyl and ethyl lactate, respectively, on supported CeO2/Al2O3 catalyst at 210-2500С was investigated. Air oxygen and a flow reactor with a fixed catalyst bed were used. A 20% solution of propylene glycol in alcohol was supplied to the reactor inlet. Oxidation of propylene glycol in the presence of methanol occurs according to the overall reaction CH3CHOHCH2OH +O2 + СН3OH = CH3CHOHCOOСН3 +2H2O. First, hydroxyacetone is formed, which is further oxidized to pyruvic aldehyde, which adds alcohol to form a hemiacetal. Next, this hemiacetal is rearranged according to Cannizzaro into methyl lactate. At 2200C and catalyst load < 2 mmol PG/gcat/h, the selectivity for methyl lactate reached 70 wt.% at 100% propylene glycol conversion. In the presence of ethanol, the formation of a significant amount of acetaldehyde and its aldol condensation products, as well as the formation of diethoxyethane, was observed. Therefore, the selectivity for ethyl lactate at 100% propylene glycol conversion did not exceed 45%.
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Ikeda, Ayumi, Chie Abe, Wakako Matsuura, and Yasuhisa Hasegawa. "Development of Methanol Permselective FAU-Type Zeolite Membranes and Their Permeation and Separation Performances." Membranes 11, no. 8 (2021): 627. http://dx.doi.org/10.3390/membranes11080627.
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The separation of non-aqueous mixtures is important for chemical production, and zeolite membranes have great potential for energy-efficient separation. In this study, the influence of the framework structure and composition of zeolites on the permeation and separation performance of methanol through zeolite membranes were investigated to develop a methanol permselective zeolite membrane. As a result, the FAU-type zeolite membrane prepared using a solution with a composition of 10 SiO2:1 Al2O3:17 Na2O:1000 H2O showed the highest permeation flux of 86,600 μmol m−2 s−1 and a separation factor of 6020 for a 10 wt% methanol/methyl hexanoate mixture at 353 K. The membrane showed a molecular sieving effect, reducing the single permeation flux of alcohol with molecular size for single-component alcohols. Moreover, the permeation flux of methanol and the separation factor increased with an increase in the carbon number of the alcohols and methyl esters containing 10 wt% methanol. In this study, the permeation behavior of FAU-type zeolite membranes was also discussed based on permeation data. These results suggest that the FAU-type zeolite membrane has the potential to separate organic solvent mixtures, such as solvent recycling and membrane reactors.
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Kutuzova, T. M., O. M. Kuznetzova, and R. A. Akhmedyanova. "Cation-exchange resins as heterogeneous catalysts for the synthesis of 1,3-butadiene from propylene and formaldehyde." Chimica Techno Acta 8, no. 2 (2021): 20218201. http://dx.doi.org/10.15826/chimtech.2021.8.2.01.
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The possibility of using the cation-exchange resin Lewatit K2420 as a catalyst for the synthesis of 1,3-butadiene from isopropyl alcohol and formaldehyde solution in one technological stage has been shown. The regularities of the process have been established and the influence of the formaldehyde form (a cyclic trimer 1,3,5-trioxane and a 37% solution in water) on the composition of the reaction mass and the yield of the main and by-products has been assessed. It has been shown that the Lewatit K2420 heterogeneous catalyst showed catalytic activity in all reactions occurring in the synthesis of 1,3-butadiene, including the decomposition of 1,3,5-trioxane, dehydration of isopropyl alcohol into propylene, condensation of propylene and formaldehyde, dehydration of 3-butene-1-ol, decomposition of 4-methyl-1,3-dioxane, etc.
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Adoor, S. G., L. S. Manjeshwar, K. S. V. Krishna Rao, B. V. K. Naidu, and T. M. Aminabhavi. "Solution and solid-state blend compatibility of poly(vinyl alcohol) and poly(methyl methacrylate)." Journal of Applied Polymer Science 100, no. 3 (2006): 2415–21. http://dx.doi.org/10.1002/app.23337.
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Park, Chul Min, Won Ju Ahn, Woong Kyu Jo, et al. "Supported CuO and ZnO Catalyst for Hydrogenation of Carbon Dioxide to Methyl Alcohol." Advanced Materials Research 550-553 (July 2012): 396–99. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.396.
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If the surface of the titanium chips (TC) was modified by thermal treatment under air atmosphere, it could be reused as catalyst support or photocatalytic materials. TC-supported CuO and ZnO catalysts were prepared by impregnation (IMP) method and co-precipitation (CP) method using cupric nitrate and zinc nitrate solution as precursors. Loading of CuO and ZnO on TC was 40.6wt% and 50.3wt%, respectively. The catalytic activity for CO2 hydrogenation was investigated using a flow-typed reactor under various pressures. Conversion of carbon dioxide to methyl alcohol over the CuO-ZnO/TC catalyst by CP and IMP methods were ca. 22% and ca. 10%, respectively. Conversion of carbon dioxide over CuO-ZnO/TC catalyst by CP method was increased with increasing reaction temperature in ranging of 15atm to 30 atm. Maximum selectivity and yield to methyl alcohol over CuO-ZnO/TC catalyst at 250°C were ca. 90% at 20 atm and ca. 18.2% at 30 atm, respectively.
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Hoogenboom, Richard, C. Remzi Becer, Carlos Guerrero-Sanchez, Stephanie Hoeppener, and Ulrich S. Schubert. "Solubility and Thermoresponsiveness of PMMA in Alcohol-Water Solvent Mixtures." Australian Journal of Chemistry 63, no. 8 (2010): 1173. http://dx.doi.org/10.1071/ch10083.
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To reduce the environmental burden of polymer processing, the use of non-toxic solvents is desirable. In this regard, the improved solubility of poly(methyl methacrylate) (PMMA) in ethanol/water solvent mixtures is very appealing. In this contribution, detailed investigations on the solubility of PMMA in alcohol/water solvent mixtures are reported based on turbidimetry measurements. PMMA revealed upper critical solution temperature transitions in pure ethanol and ethanol/water mixtures. However, around 80 wt-% ethanol content a solubility maximum was observed for PMMA as indicated by a decrease in the transition temperature. Moreover, the transition temperatures increased with increasing PMMA molar mass as well as increasing polymer concentration. Careful analysis of both heating and cooling turbidity curves revealed a peculiar hysteresis behaviour with a higher precipitation temperature compared with dissolution with less than 60 wt-% or more than 90 wt-% ethanol in water and a reverse hysteresis behaviour at intermediate ethanol fractions. Finally, the transfer of poly(styrene)-block-poly(methyl methacrylate) block copolymer micelles from the optimal solvent, i.e. aqueous 80 wt-% ethanol, to almost pure water and ethanol is demonstrated.
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Liu, Zhao Wei, Yu Fei Tang, Kang Zhao, and Heng Zhang. "Producing Nano-Porous TiO2 Fibers by Electrospinning with Phase Separation." Materials Science Forum 847 (March 2016): 218–23. http://dx.doi.org/10.4028/www.scientific.net/msf.847.218.
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TiO2 photocatalyst plays an important role in the degradation of sewage and cleaning the air. nanoporous TiO2 fibers have excellent photocatalytic properties due to their high porosity and specific surface area. Based on DMF and alcohol as solvent, nanoporous TiO2 fibers were produced by electrospinning with phase separation. The spinning dope advance rate, DMF/alcohol ratio and calcination temperature were investigated on the influence of micro-structure, porous structure, phase composition and photocatalytic performance of the nanoporous TiO2 fibers. It showed that nanoporous anatase TiO2 fibers had surface pores at 20nm by 550°C calcination. And when the proportion of DMF and alcohol was 1:3, the BET Surface Area of nanoporous TiO2 fibers was 40.75m2/g. They get photocatalytic degradation rate of 85.2% to 20mg·L-1 methyl orange solution after 35 min.
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Soloviev, Mikhail, and Valery Makaryin. "Modelling of structure and concentration characteristics of water-alcohol solutions." From Chemistry Towards Technology Step-By-Step 4, no. 4 (2023): 19–28. http://dx.doi.org/10.52957/2782-1900-2024-4-4-19-28.
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Water-alcohol solutions are widely used in pharmacy, food industry, engineering, etc. The study of their physical and chemical properties has a long history. Nevertheless, due to the complexity of these systems, there is still an interest in their research stimulated by the development of biochemistry in terms of the study and protection of the environment, global climate change, renewable energy resources and cosmochemistry. The purpose of the presented study is the quantum-chemical investigation of water clusters with methyl and ethyl alcohol molecules, as well as the modelling of concentration dependences of the excess molar volume of ethyl alcohol solution in water at different temperatures. Based on quantum-chemical calculations of paired and mixed complexes of water with methanol and ethanol, taking into account solvation effects, study reveals the formation of thermodynamically efficient complexes in liquid, in contrast to the ideal gas state, while in the mixture both individual solvated alcohol molecules and complexes will be in equilibrium. We noted a relative difference in the free energies of solvation of paired and mixed methanol and ethanol complexes. The paper proposes a technique for calculating the excess molar volume in water-alcohol mixtures by approximating the experimental dependences by Lejandre polynomials of the ninth degree. The calculation results showed high accuracy. Hence, continuous functions describe the dependences of the calculated coefficients of Lejandre polynomials on temperature.
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Podda, Enrico, Eleanor Dodd, Massimiliano Arca, et al. "N,N′-Dipropyloxamide." Molbank 2024, no. 1 (2023): M1753. http://dx.doi.org/10.3390/m1753.
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N,N′-Dipropyloxamide (1) was synthesised by the reaction between diethyloxalate and n-propylamine in ethanol. Compound 1 was fully characterised by both microanalytical (elemental analysis, melting point determination) and spectroscopic means (FT-IR and NMR spectroscopy). Crystals suitable for single crystal X-ray diffraction were isolated by the slow evaporation of a methyl alcohol solution of the compound. The resulting crystal structure shows the prominent role exerted by intermolecular hydrogen bonds in the crystal packing.
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Feitosa, Fernanda Alves, Mateus Guimarães Lage Reggiani, and Rodrigo Máximo de Araújo. "Removable partial or complete dentures exposed to beverages and mouthwashes: evaluation of microhardness and roughness." Revista de Odontologia da UNESP 44, no. 4 (2015): 189–94. http://dx.doi.org/10.1590/1807-2577.0049.
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<title>Abstract</title><sec><title>Purpose</title><p>To evaluate microhardness and roughness of denture base polymethylmethacrylate resinn exposed to acid beverages and mouthwashes.</p></sec><sec><title>Material and method</title><p>Rectangular samples (n=80) were prepared from poly (methyl methacrylate) (PMMA). They were divided into 8 groups and had the initial microhardness and Knoop roughness measured. Samples of each group were immersed for 10 min into a test solution (coffee, lemon juice, chlorhexidine gluconate, red wine, cola-based soft drink, vinegar or antiseptic with and without alcohol) and after stored in artificial saliva for 23 h and 50 min, completing a period of 24 h. This procedure was performed for 14 consecutive days and after this period the microhardness and surface roughness measurements were made again. Data were statistically analyzed using ANOVA non parametric, Kruskal-Walis and the Dunn´s test for microhardness and the t-Student and ANOVA for roughness.</p></sec><sec><title>Result</title><p>For microhardness there were found statistically significant differences among the chlorhexidine gluconate solution, antiseptic without alcohol and cola-based soft drink. For roughness was observed that the mean values between the initial period and after immersion in the test products differed statistically in all groups, without difference among groups.</p></sec><sec><title>Conclusion</title><p>The microhardness of poly(methyl methacrylate) was affected by continue exposition to chlorhexidine gluconate, antiseptic without alcohol and cola-based soft drink. The roughness of poly(methyl methacrylate) is negatively influenced by the exposure to all tested products. It may be concluded that both, microhardness and roughness, were affected by the treatments.</p></sec>
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Kashparova, Vera P., Irina B. Ilchibaeva, Nina V. Smirnova, Efim Sh Kagan, Elena N. Shubina, and Irina Yu Zhukova. "PROMOTING EFFECT OF PYRIDINE BASES ON INDIRECT ELECTROCHEMICAL OXIDATION OF ALCOHOLS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, no. 9 (2019): 33–39. http://dx.doi.org/10.6060/ivkkt.20196209.5923.
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The effect of pyridine on the reaction of indirect electrochemical oxidation of alcohols to carbonyl compounds by the catalytic system of 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxyl - iodine in a two-phase aqueous-organic medium: methylene chloride - an aqueous solution of sodium bicarbonate (pH 8.6) was studed. It was shown that the process of indirect electrochemical oxidation of alcohols is accelerated by 1.5–2 times in the presence of pyridine. The corresponding aldehydes and ketones are formed with a high yield (75-95%) after passing 2-2.2 F of electricity. Additionally, the effect of other pyridine bases (2,6-lutidine, 4-acetylpyridine, 2-methyl-5-ethylpyridine, collidine) on indirect electrochemical oxidation of alcohols was studied using the example of 1-octanol. The absence of significant differences in the promoting action of pyridine bases was established and it was shown that in all cases the octanol is obtained with a high yield and coulombic efficiency (90-95 %). A mechanism for the reaction of indirect electrochemical oxidation of alcohols with the participation of 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxyl and pyridine bases is proposed. The promoting effect of pyridine (or other pyridine bases) consists in the formation of an intermediate complex between the base, oxoammonium cation and alcohol. The formation of the complex facilitates the rapid transfer of the proton from the alcohol to the pyridine base and the hydride ion to the oxoammonium cation with the formation of the corresponding carbonyl compound from the alcohol. The preparative methods for the electrochemical synthesis of carbonyl compounds from aliphatic, cyclic, aromatic, heterocyclic alcohols including synthesis of 2,5-diformylfuran from 5-hydroxymethylfurfuralin using the two-phases catalytic system of 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxyl - potassium iodide in the presence of pyridine bases, are proposed.
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Vosooghian, Hakimeh, and Mohammad Hossein Habibi. "Photooxidation of Some Organic Sulfides under UV Light Irradiation Using Titanium Dioxide Photocatalyst." International Journal of Photoenergy 2007 (2007): 1–7. http://dx.doi.org/10.1155/2007/89759.
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The photocatalytic oxidation of three organic sulfide compounds (thioethers); methyl phenyl sulfide (MPS), benzyl phenyl sulfide (BPS), and diphenyl sulfide (dPS) using titanium dioxide (TiO2) photocatalyst suspension under UV light irradiation in aqueous-acetonitrilic (5/95), was studied. Three types of experiments were carried out: (a) the solution was eliminated from atmospheric oxygen by a flow of argon before irradiation, (b) the solution was irradiated with continuous bubbling of oxygen, and (c) the irradiation was carried out at neutral atmospheric oxygen conditions. Results showed that the process will proceed in the presence of pure oxygen much better than atmospheric oxygen or in the absence of oxygen. In fact, no detectable products were observed in the presence of atmospheric oxygen or argon flux. Besides the main products such as methyl phenyl sulfoxide, benzyl phenyl sulfoxide, diphenyl sulfoxide, diphenyl disulfide, benzaldehyde, phenyl propyl sulfide, and n-buthyl phenyl sulfide, trace concentrations of dibenzyl, biphenyl, thiophenol, benzyl alcohol, benzene, benzyl phenyl sulfone, diphenyl sulfone, and methyl phenyl sulfone were detected. Thus in summary, this study provides an example of specific, controlled oxidative chemistry in organic substrates adsorbed on photoactivatedTiO2surface.
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Takeuchi, Kazuma, Akihiro Kamaguchi, Muneaki Nabeta, Syuji Fujii, Yoshinobu Nakamura, and Takeo Iida. "Morphology and Viscoelastic Properties of Poly(Vinyl Chloride)/ Poly(Vinyl Alcohol) Incompatible Blends." Polymers and Polymer Composites 15, no. 5 (2007): 371–77. http://dx.doi.org/10.1177/096739110701500504.
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The effects of the pre-mixing method and degree of saponification poly(vinyl alcohol) (PVA) on the morphology of poly(vinyl chloride) (PVC)/PVA blends were investigated. Two pre-mixing methods were employed: a powder method and an aqueous solution method. In the powder method, both components were blended in powder form before melt kneading using a mixing roll. In the aqueous solution method, the PVC powder was added to an as-prepared PVA aqueous solution, followed by drying and then pounding before melt kneading. In the case of PVA with a degree of saponification of 98 mol%, PVA domains several hundred μm across were dispersed in the PVC matrix in the powder method system, whereas finer PVA domains with sizes ranging from sub μm to several μm were observed in the aqueous solution method. In the cases of PVA with saponification degrees of 88 and 78 mol%, domain sizes of several tens of μm were observed for both powder and solution methods. This indicates that there was no apparent influence of pre-mixing method on the domain size. When poly(methyl methacrylate) (PMMA) was added to the PVC/PVA blend, smaller PVA domains (with sizes ranging from 5 to 10 μm) were observed in both powder and solution method systems than without the PMMA. Viscoelastic properties showed specific interactions between PVC and PMMA, and between PMMA and PVA.
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Abraham, Bernard M., Kenjiro Miyano, and John B. Ketterson. "Static shear modulus of a methyl cellulose solution and viscoelasticity of a polyvinyl alcohol solution at the air/water interface." Journal of Colloid and Interface Science 107, no. 1 (1985): 264–66. http://dx.doi.org/10.1016/0021-9797(85)90170-5.
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WEERAPOL, Yotsanan, and Pornsak SRIAMORNSAK. "Differences in Viscoelasticity of Ophthalmic Polymer Solution after Sterilization." Walailak Journal of Science and Technology (WJST) 17, no. 7 (2020): 686–97. http://dx.doi.org/10.48048/wjst.2020.6341.
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Polymer solution has been used for increasing viscosity of ophthalmic solution in order to prolong the retention of active drug in the eye. The ophthalmic solution must be sterilized, which may affect the rheology properties of viscosity-inducing polymers. The aim of this study was to investigate the effect of sterilization treatment on viscosity-inducing agents (i.e., poloxamer, polyvinyl alcohol; (PVA), methyl cellulose (MC), polyvinylpyrrolidone (PVP) and carbomer). The effect of membrane filtration and steam sterilization or autoclaving (121 °C, 15 Ib/inch2, 15 min) were determined. A rheometer was used to investigate the viscosity and viscoelastic properties between treated and untreated polymer solutions. The power law model, consistency index (k), and power law index (n) of polymer solution viscosity were compared. For viscoelastic properties, storage modulus and loss modulus were examined. The results demonstrated that, viscosity of carbomer and MC solution (1 and 2 %) were changed after steam sterilization. No difference in viscosity was observed for PVP, PVA and poloxamer solution, between untreated and treated samples. The storage and loss moduli of PVA solution after autoclaving were not different when comparing with the untreated polymer solution. From this study, it could be concluded that the sterilization treatment influenced the viscosity behavior and viscoelastic properties of polymer solution used as viscosity-inducing agent in ophthalmic solution. Therefore, the selection of polymer and sterilization method should be carefully considered.
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Abdel-Karim, R., M. Ramadan, and S. M. El-Raghy. "Morphology and Electrochemical Characterization of Electrodeposited Nanocrystalline Ni-Co Electrodes for Methanol Fuel Cells." Journal of Nanomaterials 2018 (August 7, 2018): 1–13. http://dx.doi.org/10.1155/2018/9870732.
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An electrocatalytic electrode surface was developed for alcoholic fuel cell by electrodeposition of Ni-Co alloy on a 301 stainless steel substrate. Material characterization by EDX and XRD confirmed deposition of Ni-Co alloy on stainless steel surfaces with a cobalt content of 15–35%. SEM showed nodular and/or angular particles with some subparticles embedded within the coarse nodules. Increasing the deposition current density as well as deposition time leads to deposition of Ni-Co alloys characterized by coarse angular morphology with lower cobalt content. The electrocatalytic activity of the coated electrodes was characterized by potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) tests in anodic solution for electrochemical oxidation of methanol. Polarization study showed very much higher current density for the coated electrode compared to bare stainless steel. According to the EIS test in 1 M methyl alcohol acidic solution, it was found that polarization resistance of the coated sample was much lower compared to the bare substrate. The electrical equivalent circuit at the metal solution interface was found to be matching Randle with Warburg resistance. The results of the CV test showed higher peaks for alcohol oxidation and oxygen reduction compared to the bare substrate. The alloy coating with increased effective surface area leads to enhancement in the electrocatalytic activity of the electrodes. The alloys deposited at current densities of 50 and 80 mA/cm2 for 30 minutes (15–16% Co) had higher catalytic activity of the Ni-Co nanocrystalline deposits for methanol oxidation for direct methanol fuel cells, than those under other deposition conditions.
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Bykov, Denis S., Yulia V. Shulevich, Ekaterina G. Dukhanin, Alexander V. Navrotskii, and Ivan A. Novakov. "INTERACTION OF TRIMETHYL[METHACRYLOYLOXYETHYL]AMMONIUM METHYL SULFATE WITH SODIUM DODECYL SULFATE AND PROPERTIES OF THE RESULTING POLYELECTROLYTES." ChemChemTech 68, no. 7 (2025): 114–24. https://doi.org/10.6060/ivkkt.20256807.7198.
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Radical template polymerization is a promising method for synthesizing polyelectrolytes, allowing controlling simultaneously both the molecular weight and polydispersity of polymers. The use of surfactant micelles instead of traditionally used macromolecular templates allows solving the main problem of matrix synthesis – isolation of the obtained polymer. In this work, the influence of the cationic monomer - trimethyl[methacryloyloxyethyl]ammonium methyl sulfate and dodecyl alcohol contained in the oppositely charged surfactant - sodium dodecyl sulfate, on its micelle formation was studied by the methods of fluorescence spectrophotometry, solubilization of the oil-soluble dye Oil Yellow OB, capillary viscometry, conductometry and tensometry. Critical micelle concentrations corresponding to the formation of spherical, spheroidal micelles, as well as cylindrical micelles forming a network of entanglements, have been determined. It has been established that temperature, while having little effect on the values of the first and second critical micelle concentrations, has a noticeable effect on the value of the third critical micelle concentration. Radical matrix polymerization of trimethyl[methacryloyloxyethyl]ammonium methyl sulfate on spheroidal sodium dodecyl sulfate micelles has been carried out under conditions of an equimolar monomer/sodium dodecyl sulfate ratio in the presence of 2,2'-azobis(2-methylpropionamidine) dihydrochloride as a radical polymerization initiator. The characteristic viscosities of the synthesized polyelectrolytes and the Huggins constants in a sodium nitrate solution have been determined by capillary viscometry. Polyelectrolytes synthesized on micelles are characterized by higher values of intrinsic viscosity than polyelectrolytes obtained in aqueous solution in the absence of surfactants. The difference in the values of intrinsic viscosity is due to the mutual influence of dodecyl alcohol and trimethyl[methacryloyloxyethyl]ammonium methyl sulfate on the size and shape of sodium dodecyl sulfate micelles. For citation: Bykov D.S., Shulevich Yu.V., Dukhanina E.G., Navrotsky A.V., Novakov I.A. Interaction of trimethyl[methacryloyloxyethyl]ammonium methyl sulfate with sodium dodecyl sulfate and properties of the resulting polyelectrolytes. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 7. P. 114-124. DOI: 10.6060/ivkkt.20256807.7198.
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Akiyama, Kensuke, Yuu Motoizumi, Tetsuya Okuda, Hiroshi Funakubo, Hiroshi Irie, and Yoshihisa Matsumoto. "Synthesis and Photocatalytic Properties of Iron Disilicide/SiC Composite Powder." MRS Advances 2, no. 8 (2017): 471–76. http://dx.doi.org/10.1557/adv.2017.221.
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ABSTRACTSemiconducting iron disilicide (β-FeSi2) island grains of 50-100 nanometers in size were formed on the surface of Au-coated 3C-SiC powder by metal-organic chemical vapor deposition. On the surface of 3C-SiC powder, the Au-Si liquidus phase was obtained via a Au-Si eutectic reaction, which contributed to the formation of the β-FeSi2 island grains. This β-FeSi2/SiC composite powder could evolve hydrogen (H2) from methyl-alcohol aqueous solution under irradiation of visible light with wavelengths of 420-650 nm.
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Juliarnita, I. Gede Aditya, Rositayanti Hadisoebroto, and Astri Rinanti. "Bioethanol production from mixed culture microalgae biomass with temperature hydrolysis variation." MATEC Web of Conferences 197 (2018): 13010. http://dx.doi.org/10.1051/matecconf/201819713010.
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This preliminary study aims to exploit the biomass of microalgae Chlorella vulgaris; Scenedesmus obliquus; and Chlorococcum sp. in the form of a mixed culture as raw material of alternative fuels. Microalgae were cultivated in the artificial growth medium of PHM (Provasoli Haematococcus Media) for 9 days to reach the exponential phase. Hydrolysis was carried out at a temperature variation of (oC) 25; 80; 100; 120; 140; 160 within 30 minutes by adding hydrochloric acid. Biomass fermentation by adding 50% (v/v) Saccharomyces cerevisiae for 5 day to produce alcohol compounds. The last stage is separation of the alcohol compounds from another compounds by distillation. The result showed that carbohydrate levels with color change indicator in luff schoorl solution at hydrolysis and fermentation stages severely were 12.20 mg/L. Carbohydrate levels in fermentation stage produced 17% (v/v) alcohol compounds while in the distillation stage, 98% (v/v) alcohol will be separated into intermediate compounds such as linoleic acid and methyl alcohol as a characteristic of bioethanol. At 80oC of hydrolysis temperature, 58% bioethanol was produced. Further research is needed, since the preliminary study proves the mixed culture of microalgae is potentially to be utilized in producing bioethanol.
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Ikumapayi, O. M. "Performance Analysis of Tellus 68 Lubricating Oil On Shiroro Hydro Power Turbo Generator." J. of Advancement in Engineering and Technology 5, no. 2 (2017): 05. https://doi.org/10.5281/zenodo.3826093.
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Shiroro Power Station, Niger State, Nigeria had not been able to effectively generate its own quota of electricity to the Nigerian National grid because of frequent shut down of the turbo generators as a result overheating within the Upper guide bearing (UGB)with the use of Tellus 68 oil for lubrication of the generating units. This work involved laboratory evaluation of the performance characteristics of Tellus 68 to determine the effects on the temperature variation within the lower and upper guide bearing of the hydro unit. The procedures involved in the experiment were: determination of viscosity; flash point, pour point, neutralization number; water and ash contents. The equipment used for the tests consist of Chan U-Tube Viscometer; Pesky- Martens Closed Flash Tester; Brian Weigh Cylindrical Test Jar; Armfield Potentiometric Titrimeter; Pyrox Water Content Apparatus; Bausch and Loub Evaporating Crucible Electric and Muffle Furnace. Reagents used includes Alcohol, Potassium Hydroxide (KOH); Phenolphthalein Solution; Methyl Orange Solution; Alkali Blue Solution ; Ethyl Alcohol; Toluene; N-Xylene; Silicone Oil; Premium Motor Spirit; Chlorobenzene; Solid Carbon Dioxide; Ethanol; Pyrogallol and Zinc Oxide. The results experiments conducted through a series of ASTM/IP tests when compared with manufacturer’s specification shows that Tellus 68 Oil is suitable for effective lubrication of hydro power turbo generators.
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Mariem M. A.AL-Abas and Jassem. M. Nasser. "OPTIMAL CONDITIONS FOR EXTRACTION PHENOLIC COMPOUNDS AND FLAVONOIDS FROM MILLET BRAN AND STUDYING SOME OF THEIR BIOLOGICAL ACTIVITY." IRAQI JOURNAL OF AGRICULTURAL SCIENCES 56, Special (2025): 57–67. https://doi.org/10.36103/d7vwy494.
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The aim of this research is to determine the optimal conditions for extracting phenols and flavonoids from the bran of Iraqi proso millet and Ukrainian foxtail millet, whole and defatted, and studying some of their biological characteristics. Petroleum ether, methyl alcohol (60% and 80%), distilled water, and ethyl alcohol at concentrations of 60, 80, 90, and 99% were used as extraction solutions. The flavonoid content was estimated using the Rutin standard curve, and the phenolic content was determined using the Folin-Ciocateau method based on the gallic acid standard curve. The results showed that the concentration of phenolic compounds and flavonoids in proso millet bran extracts were (770.56, 865.38, 1059.94, 883.16, 722.17, 726.12, 587.79, 400.69) µg/g and (188.26, 196.26, 353.60, 671.38, 96.94, 93.60, 117.60, 300.60) µg /g, respectively, and in Ukrainian millet bran extracts (889.08, 1034.80, 1182.00, 1331.17, 1008.19, 990.42, 592.85, 581.43) µg /g and (302.94, 484.26, 758.94, 940.32, 188.26, 97.60, 217.60, 554.94) µg/g respectively. The highest phenolic and flavonoids compounds concentrations were achieved when ethyl alcohol (99%) as extraction solution was used for Ukrainian millet. Therefore, this treatment was adopted in conducting the free radical scavenging test, at different concentrations (0.125, 0.250, 0.500, 0.750, 0.800) mg/ml, as RSA were (24.68, 40.18, 67.56, 81.98, 89.55%), respectively, compared to ascorbic acid at the same concentrations, which were (40.14, 57.34, 73.46, 89.93, 99.55%).
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Kadem, Burak Yahya. "Studying the properties of ternary PEDOT:PSS thin films for solar cell application." Nanomaterials and Energy 14, no. 2 (2025): 1–10. https://doi.org/10.1680/jnaen.24.00014.
Full textAbstract:
Poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester–based organic solar cell is used to investigate the effects of treated poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic-acid (PEDOT:PSS) as a hole transport layer. This layer is treated with different alcohol solutions based on the polarity and mixture. The variation in the polarity of alcohol and their effects on the organic solar cell parameters and behavior were studied and evaluated using different techniques such as atomic force microscopy with the aid of using WSxM software involving the application of two-dimensional fast Fourier transforms analysis. Contact angle measurement is also used to measure the hydrophilicity and hydrophobicity of the PEDOT:PSS solution on the top of substrates. An interdigitated electrode is employed to measure the electrical conductivity of the PEDOT:PSS layers; such results are significant in the solar cell application. The latter is characterized using I–V characteristics and IPCE measurement and the results revealed a good enhancement in the solar cell performance with good stability. Inverted structure is also demonstrated, and the results suggest that the treated PEDOT:PSS layer is promising in the field of inverted OSCs.
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Koysuren, Ozcan. "Preparation and characterization of polyvinyl alcohol/carbon nanotube (PVA/CNT) conductive nanofibers." Journal of Polymer Engineering 32, no. 6-7 (2012): 407–13. http://dx.doi.org/10.1515/polyeng-2012-0068.
Full textAbstract:
Abstract The aim of this study was to prepare polyvinyl alcohol/carbon nanotube (PVA/CNT) conductive nanofibers by the electrospinning process. Prior to composite preparation, carbon nanotubes are dispersed homogeneously in N-methyl-2-pyrrolidone (NMP) and mixed with a PVA solution. A series of PVA/CNT films and nanofibers with various CNT compositions are prepared. Electrical conductivity and specific capacitance of spin-coated PVA/CNT films and electrospun PVA/CNT fibers increase with an increase in CNT content. Electrospun PVA/CNT nanofibers with a larger electrode surface result in a higher specific capacitance when compared with spin-coated PVA/CNT films. According to the morphology analysis, homogeneous and highly porous PVA/CNT mats containing 50–300 nm diameter nanofibers are obtained by the electrospinning process.
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Lobanova, V. V., F. I. Vismont, and S. V. Gubkin. "Significance of the activity of liver arginase and Kupffer cells in the detoxification processes and the thyroid status formation in rats under alcoholic intoxication of different severity." Doklady of the National Academy of Sciences of Belarus 66, no. 1 (2022): 76–82. http://dx.doi.org/10.29235/1561-8323-2022-66-1-76-82.
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Modern medicine faces the problem of a steady growth of alcoholic pathology. As you know, morbidity and mortality with a regular consumption of alcoholic beverages is associated with the toxic effects of ethanol on the most important human organs and, first of all, on the liver. To date, a sufficient number of facts are accumulated, indicating the importance of liver arginase and Kupffer cells in vital processes in health and disease. The aim of the study was to elucidate the significance of the activity of liver arginase and Kupffer cells in the detoxification processes and the thyroid status formation in rats with chronic ethanol intoxication of different severity. In rat experiments using modern physiological, biochemical research methods and a pharmacological approach, it was found that liver arginase and Kupffer cells participate in changes in the liver detoxification function and the thyroid status formation induced by chronic ethanol intoxication. The activity of liver arginase and Kupffer cells determines the severity of detoxification processes and the thyroid status formation in chronic alcohol intoxication. The direction and severity of changes in the arginase activity and the liver detoxification function during chronic alcoholism depends on the severity of chronic alcohol intoxication. Under the influence of daily intragastric administration for 60 days, a 30 % aqueous solution of ethanol (3.5 g 92 % ethanol per kg of body weight) in animals inhibited the activity of liver arginase and the detoxification function, but the introduction of a 10 % aqueous solution of ethanol (1.0 g 92 % ethanol per kg of body weight) within 2 months leads to an increase in the activity of liver arginase and detoxification processes. Kupffer cells depression by GdCl3 as the action in the body of the NO-synthase inhibitor methyl ester NG-nitro-L-arginine weakens and the arginase inhibitor Nω-hydroxy-nor-L-arginine contributes to the development of characteristic changes in the processes of detoxification and triiodothyronine level in plasma during chronic alcohol intoxication caused by intragastric introduction of ethanol at a dose of 3.5 g/kg for 60 days.
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Shi, Wen Ying, Hong Bin Li, and Rong Zhou. "Preparation and Characterization of the Sulfonated Polymer/Non-Woven Fiber Composite Catalytic Membrane for Esterification." Applied Mechanics and Materials 628 (September 2014): 44–47. http://dx.doi.org/10.4028/www.scientific.net/amm.628.44.
Full textAbstract:
A novel composite catalytic membrane as heterogeneous acid catalyst for biodiesel production was prepared from zirconium sulfate (Zr (SO4)2) and sulfonated poly (vinyl alcohol) (SPVA) solution supported on/inside PET non-woven fabrics by the phase inversion method. Membrane structure was characterized by Field Emission scanning electron microscope (FESEM). The effect of polymer concentration on membrane morphologies was investigated. The catalytic performance of the composite membrane demonstrated an increasing from 73.04% to 56.72% with the increasing the membranes porosities increased from 37% to 68%. And the optimum molar ratio of methanol/oleic acid to produce methyl esters was 3:1.