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Sample records for 1-propanol

  1. Study on Ionization Energies of 3-Amino-1-propanol

    Ke-dong Wang; Ying-bin Jia; Zhen-jiang Lai; Yu-fang Liu

    2011-01-01

    Fourteen conformers of 3-amino-1-propanol as the minima on the potential energy surface are examined at the MP2/6-311++G** level. Their relative energies calculated at B3LYP,MP3 and MP4 levels of theory indicated that two most stable conformers display the intramolecular OH…N hydrogen bonds. The vertical ionization energies of these conformers calculated with ab initio electron propagator theory in the P3/aug-cc-pVTZ approximation are in agreement with experimental data from photoelectron spectroscopy. Natural bond orbital analyses were used to explain the differences of IEs of the highest occupied molecular ortibal of conformers. Combined with statistical mechanics principles, conformational distributions at various temperatures are obtained and the temperature dependence of photoelectron spectra is interpreted.

  2. Effect Of Polar Component(1-Propanol On The RelativeVolatility Of The Binary System N-Hexane - Benzene

    Khalid Farhod Chasib Al-Jiboury

    2008-01-01

    Full Text Available Vapor-liquid equilibrium data are presented for the binary systems n-hexane - 1-propanol, benzene - 1-propanol and n-hexane – benzene at 760 mm of mercury pressure. In addition ternary data are presented at selected compositions with respect to the 1-propanol in the 1-propanol, benzene, n-hexane system at 760 mmHg. The results indicate the relative volatility of n-hexane relative to benzene increases appreciably with addition of 1-propanol

  3. Dehydration pathways of 1-propanol on HZSM-5 in the presence and absence of water

    Zhi, Yuchun; Shi, Hui; Mu, Linyu; Liu, Yue; Mei, Donghai; Camaioni, Donald M.; Lercher, Johannes A.

    2015-12-23

    The Brønsted acid-catalyzed gas-phase dehydration of 1-propanol (0.075-4 kPa) was studied on zeolite H-MFI (Si/Al = 26, containing minimal amounts of extraframework Al moieties) in the absence and presence of co-fed water (0-2.5 kPa) at 413-443 K. It is shown that propene can be formed from monomeric and dimeric adsorbed 1-propanol. The stronger adsorption of 1-propanol relative to water indicates that the reduced dehydration rates in the presence of water are not a consequence of the competitive adsorption between 1-propanol and water. Instead, the deleterious effect is related to the different extents of stabilization of adsorbed intermediates and the relevant elimination/substitution transition states by water. Water stabilizes the adsorbed 1-propanol monomer significantly more than the elimination transition state, leading to a higher activation barrier and a greater entropy gain for the rate-limiting step, which eventually leads to propene. In a similar manner, an excess of 1-propanol stabilizes the adsorbed state of 1-propanol more than the elimination transition state. In comparison with the monomer-mediated pathway, adsorbed dimer and the relevant transition states for propene and ether formation are similarly, while less effectively, stabilized by intrazeolite water molecules. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, and was performed in part using the Molecular Sciences Computing Facility (MSCF) in the William R. Wiley Environmental Molecular Sciences Laboratory, a DOE national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located and the Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for DOE.

  4. Photodissociation dynamics of 1-propanol and 2-propanol at 193.3 nm

    193.3-nm photodissociation dynamics of jet-cooled 1-propanol and 2-propanol and their partially deuterated variants are examined by using the high-n Rydberg-atom time-of-flight technique. Isotope labeling studies show that O-H bond fission is the primary H-atom production channel in the ultraviolet photodissociation of both 1-propanol and 2-propanol. Center-of-mass (c.m.) product translational energy release of the RO-H dissociation channel is large, with T>=0.78 for H+1-propoxy (n-propoxy) and 0.79 for H+2-propoxy (isoproxy). Maximum c.m. translational energy release yields an upper limit of the O-H bond dissociation energy: 433±2 kJ/mol in 1-propanol and 435±2 kJ/mol in 2-propanol. H-atom product angular distribution is anisotropic (with β≅-0.79 for 1-propanol and -0.77 for 2-propanol), suggesting an electronic transition moment perpendicular to the H-O-C plane and a short excited-state dissociation lifetime (less than a rotational period). Information about photodissociation dynamics and bond energies of the partially deuterated propanols are also obtained. The 193.3-nm photodissociation dynamics of 1-propanol and 2-propanol are nearly identical to each other and are similar to those of methanol and ethanol. This indicates a common RO-H dissociation mechanism: after the nO→σ*(O-H)/3s excitation localized on the H-O-C moiety, the H atom is ejected promptly in the H-O-C plane in a time scale shorter than a rotational period of the parent molecule, and it dissociates along the O-H coordinate on the repulsive excited-state potential-energy surface with a large translational energy release

  5. UNIQUAC activity coefficient model for the systems of 1-propanol + water and 2-propanol + water

    Numuang, C.; Kaewsichan, L.

    2005-01-01

    Predictions of vapor liquid equilibria and azeotrope conditions of binary systems of 1-propanol+ water and 2-propanol+water at 30, 60, and 100 kPa were conducted in this work. UNIQUAC activity coefficient and ideal gas models represented behavior of the systems in liquid phase and vapor phase respectively. Experimental data collected from the literature (Gobaldon et al., 1996 and Marzal et al., 1996) were used to calculate energy interaction parameters of the UNIQUAC activity coefficient mode...

  6. Molecular conformation and structural correlations of liquid D-1-propanol through neutron diffraction

    A Sahoo; S Sarkar; P S R Krishna; V Bhagat; R N Joarder

    2008-07-01

    An analysis of neutron diffraction data of liquid deuterated 1-propanol at room temperature to extract its molecular conformation is presented. Being a big molecule with twelve atomic sites, the analysis is tricky and needs careful consideration. The resulting molecular parameters are compared with electron diffraction (gas phase), X-ray diffraction (liquid phase) and MD simulation results. Information about the hydrogen-bonded intermolecular structure in liquid is extracted and nature of the probable molecular association suggested.

  7. Optimization of lipase-catalyzed enantioselective production of 1-phenyl 1-propanol using response surface methodology.

    Soyer, Asli; Bayraktar, Emine; Mehmetoglu, Ulku

    2010-01-01

    Optically active 1-phenyl 1-propanol is used as a chiral building block and synthetic intermediate in the pharmaceutical industries. In this study, the enantioselective production of 1-phenyl 1-propanol was investigated systematically using response surface methodology (RSM). Before RSM was applied, the effects of the enzyme source, the type of acyl donor, and the type of solvent on the kinetic resolution of 1-phenyl 1-propanol were studied. The best results were obtained with Candida antartica lipase (commercially available as Novozym 435), vinyl laurate as the acyl donor, and isooctane as the solvent. In the RSM, substrate concentration, molar ratio of acyl donor to the substrate, amount of enzyme, temperature, and stirring rate were chosen as independent variables. The predicted optimum conditions for a higher enantiomeric excess (ee) were as follows: substrate concentration, 233 mM; molar ratio of acyl donor to substrate, 1.5; enzyme amount, 116 mg; temperature, 47 °C; and stirring rate, 161 rpm. A verification experiment conducted at these optimized conditions for maximum ee yielded 91% for 3 hr, which is higher than the predicted value of 83%. The effect of microwave on the ee was also investigated and ee reached 87% at only 5 min. PMID:21108142

  8. UNIQUAC activity coefficient model for the systems of 1-propanol + water and 2-propanol + water

    Numuang, C.

    2005-12-01

    Full Text Available Predictions of vapor liquid equilibria and azeotrope conditions of binary systems of 1-propanol+ water and 2-propanol+water at 30, 60, and 100 kPa were conducted in this work. UNIQUAC activity coefficient and ideal gas models represented behavior of the systems in liquid phase and vapor phase respectively. Experimental data collected from the literature (Gobaldon et al., 1996 and Marzal et al., 1996 were used to calculate energy interaction parameters of the UNIQUAC activity coefficient model by non-linear regression method. The obtained parameters were not dependent on temperature and mole fraction; however, those parameters were dependent on pressure of the system. The mean absolute error of vapor mole fraction of alcohol and water were in the range 3.86-4.65% and 2.33-3.28% respectively for the binary system of 1-propanol +water. The mean absolute error of vapor mole fraction of alcohol and water were in the range 1.93-2.06% and 1.47-1.94% respectively for the binary system of 2-propanol+water. The thermodynamics consistency test proved that the UNIQUAC activity coefficient model was satisfied very well with Gibbs- Duhem equation.

  9. Fluid Phase Topology of Benzene + Cyclohexane + 1-Propanol at 101.3 kPa

    Andrade, R. S.; Iglesias, M.

    2015-07-01

    Isobaric vapor-liquid equilibria for the benzene + cyclohexane + 1-propanol ternary mixture were experimentally investigated at atmospheric pressure. Data were tested and considered thermodynamically consistent by means of the McDermott and Ellis method. The experimental results showed that this ternary mixture is completely miscible and exhibits three binary minimum homogeneous azeotropes and a ternary minimum azeotrope at the studied conditions. Satisfactory results were obtained for correlation of equilibrium compositions with the UNIQUAC equation and also for prediction with the UNIFAC method. In both cases, low root-mean-square deviations of the vapor mole fraction and temperature were calculated. The capability of 1-propanol as a modified distillation agent at atmospheric conditions is discussed in terms of thermodynamic topological analysis. However, because of the complex topology of the ternary mixture, it leads to a distillation scheme with two columns specifying ternary azeotrope recycling and difficult operation. Thus, this compound is not recommended as a separation agent for the binary benzene + cyclohexane azeotrope.

  10. Enthalpy of solution of CO2 in aqueous solutions of 2-amino-2-methyl-1-propanol

    The enthalpies of solution of CO2 in aqueous solution of 2-amino-2-methyl-1-propanol (AMP) 15 wt% and 30 wt% were measured at 322.5 K and pressures range from (0.2 to 5) MPa using a flow calorimetric technique. The gas solubilities were simultaneously determined from the calorimetric data. The solubilities were compared to available literature values obtained by direct measurements. The experimental enthalpies of solution were compared to the values derived from the literature vapor liquid equilibrium data. This work provides calorimetric data that will be used later for the development of a thermodynamic model to predict both solubilities and enthalpies of solution of acid gases in aqueous amine solutions

  11. Intermolecular interactions in mixtures of ethyl formate with methanol, ethanol, and 1-propanol on density, viscosity, and ultrasonic data

    Elangovan, S.; Mullainathan, S.

    2014-12-01

    Density (ρ), viscosity (η), and ultrasonic velocity ( U) have been measured for binary mixtures of ethyl formate with methanol, ethanol, and 1-propanol at 303 K. From the experimental data, adiabatic compressibility (β), acoustic impedance ( Z), viscous relaxation time (τ), free length ( L f), free volume ( V f), internal pressure (πi), and Gibbs free energy (Δ G) have been deduced. It is shown that strength of intermolecular interactions between ethyl formate with selected 1-alcohols were in the order of methanol < ethanol < 1-propanol.

  12. Novel Dehalogenase Mechanism for 2,3-Dichloro-1-Propanol Utilization in Pseudomonas putida Strain MC4

    Arif, Muhammad Ilan; Samin, Ghufrana; van Leeuwen, Jan G. E.; Oppentocht, Jantien; Janssen, Dick B.

    2012-01-01

    A Pseudomonas putida strain (MC4) that can utilize 2,3-dichloro-1-propanol (DCP) and several aliphatic haloacids and haloalcohols as sole carbon and energy source for growth was isolated from contaminated soil. Degradation of DCP was found to start with oxidation and concomitant dehalogenation catal

  13. Solvatochromism and preferential solvation in mixtures of Methanol with Ethanol, 1-Propanol and 1-Butanol

    Masoumeh Sayadian

    2014-12-01

    Full Text Available The spectral shift of 4-nitroaniline was determined in pure methanol, ethanol, 1-propanol and 1-butanol and binary mixtures of methanol with other 1-alkanols at 25 ⁰C by UV-vis spectroscopy. The effect of specific and non-specific solute-solvent interactions on the spectral shift was investigated by using the linear solvation energy relationship concept. A multiple linear regression analysis was used to correlate the spectral shift with microscopic Kamlet-Taft parameters (a, b and p* in pure solvents. Results indicate that the spectral shift is highly related with the specific solute-solvent interactions. In binary mixtures, a nonideal behavior of spectral shift was observed respective to the analytical mole fraction of alcohols; indicating preferential solvation. The spectral shifts were fitted to a known preferential solvation model named solvent exchange model to calculate the preferential solvation parameters. The preference of solute to be solvated by one of the solvating species relative to others was explained in terms of solvent-solvent and solute-solvent interactions.

  14. Production of the aroma chemicals 3-(methylthio)-1-propanol and 3-(methylthio)-propylacetate with yeasts.

    Etschmann, M M W; Kötter, P; Hauf, J; Bluemke, W; Entian, K-D; Schrader, J

    2008-09-01

    Yeasts can convert amino acids to flavor alcohols following the Ehrlich pathway, a reaction sequence comprising transamination, decarboxylation, and reduction. The alcohols can be further derivatized to the acetate esters by alcohol acetyl transferase. Using L: -methionine as sole nitrogen source and at high concentration, 3-(methylthio)-1-propanol (methionol) and 3-(methylthio)-propylacetate (3-MTPA) were produced with Saccharomyces cerevisiae. Methionol and 3-MTPA acted growth inhibiting at concentrations of >5 and >2 g L(-1), respectively. With the wild type strain S. cerevisiae CEN.PK113-7D, 3.5 g L(-1) methionol and trace amounts of 3-MTPA were achieved in a bioreactor. Overexpression of the alcohol acetyl transferase gene ATF1 under the control of a TDH3 (glyceraldehyde-3-phosphate dehydrogenase) promoter together with an optimization of the glucose feeding regime led to product concentrations of 2.2 g L(-1) 3-MTPA plus 2.5 g L(-1) methionol. These are the highest concentrations reported up to now for the biocatalytic synthesis of these flavor compounds which are applied in the production of savory aroma compositions such as meat, potato, and cheese flavorings. PMID:18597084

  15. Enthalpies of dilution of glycine and L-alanine in aqueous 1-propanol solutions at T = 298.15 K

    The dilution enthalpies of glycine and L-alanine in aqueous 1-propanol solutions have been measured by a mixing-flow microcalorimeter at T = 298.15 K. The homogeneous enthalpic interaction coefficients of the two zwitterions have been calculated according to the analysis of the excess enthalpy suggested by Friedman [J. Solution Chem. 1 (1972) 387-390]. The enthalpic pairwise interaction coefficients h2 of glycine are negative and pass through a minimum with increasing 1-propanol content in mixed solvents, while those of L-alanine decrease from positive to negative. The variations of the enthalpic pairwise interaction coefficients are interpreted in terms of solute - solute and solute - solvent interactions

  16. Quantitative NMR spectroscopy of binary liquid mixtures (aldehyde + alcohol) Part I: Acetaldehyde + (methanol or ethanol or 1-propanol)

    Highlights: • Formation of hemiacetal/poly(oxymethylene) hemiacetals in liquid binary mixtures. • Acetaldehyde and a low molecular alcohol (methanol or ethanol or 1-propanol). • Quantitative 13C NMR spectroscopy at temperatures between (255 and 295) K. • Hemiacetals are the predominant species. • (Acetaldehyde + methanol (50 + 50)) at 255 K: hemiacetal (polymers) >80% (≈10%). -- Abstract: Aldehydes react with alcohols to hemiacetals and poly(oxymethylene) hemiacetals. The chemical reaction equilibria of such reactions, in particular in the liquid state, can have an essential influence on the thermodynamic properties and related phenomena like, for example, on the vapour + liquid phase equilibrium. Therefore, thermodynamic models that aim to describe quantitatively such phase equilibria have to consider the chemical reaction equilibrium in the coexisting phases. This is well known in the literature for systems such as, for example, formaldehyde and methanol. However, experimental information on the chemical reaction equilibria in mixtures with other aldehydes (than formaldehyde) and alcohols is extremely scarce. Therefore, quantitative NMR spectroscopy was used to investigate the chemical reaction equilibria in binary mixtures of acetaldehyde and a single alcohol (here either methanol, ethanol or 1-propanol) at temperatures between (255 and 295) K. The results reveal that the majority of the constituents of the mixture is present as hemiacetal and the first two poly(oxymethylene) hemiacetals: in an equimolar mixture of (acetaldehyde + methanol or ethanol or 1-propanol), between about 90% at T = 255 K and about 75% at 295 K. The mole-fraction based chemical reaction equilibrium constants for the formation of those species were determined and some derived properties are reported

  17. Complementary vapor pressure data for 2-methyl-1-propanol and 3-methyl-1-butanol at a pressure range of (15 to 177) kPa

    Bejarano, Arturo; Quezada, Nathalie [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (Chile); Fuente, Juan C. de la [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (Chile)], E-mail: juan.delafuente@usm.cl

    2009-09-15

    The vapor pressure of pure 2-methyl-1-propanol and 3-methyl-1-butanol, components called congeners that are present in aroma of wine, pisco, and other alcoholic beverages, were measured with a dynamic recirculation apparatus at a pressure range of (15 to 177) kPa with an estimated uncertainty <0.2%. The measurements were performed at temperature ranges of (337 to 392) K for 2-methyl-1-propanol and (358 to 422) K for 3-methyl-1-butanol. Data were correlated using a Wagner-type equation with standard deviations of 0.09 kPa for the vapor pressure of 2-methyl-1-propanol and 0.21 kPa for 3-methyl-1-butanol. The experimental data and correlation were compared with data selected from the literature.

  18. Molecular probe dynamics and free volume in organic glass-formers and their relationships to structural relaxation: 1-propanol

    A joint study of the rotational dynamics and free volume in amorphous 1-propanol (1-PrOH) as a prototypical monohydroxy alcohol by electron spin resonance (ESR) or positron annihilation lifetime spectroscopy (PALS), respectively, is reported. The dynamic parameters of the molecular spin probe 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and the annihilation ones of the atomic ortho-positronium (o-Ps) probe as a function of temperature are compared. A number of coincidences between various effects in the ESR and PALS responses at the corresponding characteristic ESR and PALS temperatures were found suggesting a common origin of the underlying dynamic processes that were identified using viscosity (VISC) in terms of the two-order parameter (TOP) model and broadband dielectric spectroscopy (BDS) data. (paper)

  19. Prebiotic Polymerization: Oxidative Polymerization of 2,3 Dimercapto-1- Propanol on the Surface of Iron(III) Hydroxide Oxide

    Weber, Arthur L.

    1995-01-01

    The oxidation of 2,3-dimercapto-1-propanol by ferric ions on the surface of iron(III) hydroxide oxide (Fe(OH)O) yielded polydisulfide oligomers. This polymerization occurred readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron(III) hydroxide oxide (20 mg, 160 micromole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the FE(OH)O phase. Reactions carried out at the same ratio of dithiol to FE(OH)O but at higher dithiol concentrations gave higher yields of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis is discussed.

  20. Prebiotic polymerization: Oxidative polymerization of 2, 3-dimercapto-1-propanol on the surface of iron(III) hydroxide oxide

    Weber, Arthur L.

    1995-01-01

    The oxidation of 2, 3-dimercapto-1-propanol by ferric ions on the surface of iron(III) hydroxide oxide (Fe(OH)O) yielded polydisulfide oligomers. This polymerization occurred readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron(III) hydroxide oxide (20 mg, 160 micromole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the Fe(OH)O phase. Reactions carried out at the same ratio of dithiol to Fe(OH)O but at higher dithiol concentrations gave higher yields of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis is discussed.

  1. Experimental and theoretical excess molar enthalpies of ternary and binary mixtures containing 2-Methoxy-2-Methylpropane, 1-propanol, heptane

    Highlights: • Experimental enthalpies for the ternary system MTBE + propanol + heptane were measured. • No experimental ternary values were found in the currently available literature. • Experimental enthalpies for the binary system propanol + heptane were measured. • Excess molar enthalpies are positive over the whole range of composition. • The ternary contribution is also positive, and the representation is asymmetric. -- Abstract: Excess molar enthalpies, at the temperature of 298.15 K and atmospheric pressure, have been measured for the ternary system {x1 2-Methoxy-2-Methylpropane (MTBE) + x2 1-propanol + (1 − x1 − x2) heptane}, over the whole composition range. Also, experimental data of excess molar enthalpy for the involved binary mixture {x 1-propanol + (1 − x) heptane} at the 298.15 K and atmospheric pressure, are reported. We are not aware of any previous experimental measurement of excess enthalpy in the literature for the ternary system presented in this study. Values of the excess molar enthalpies were measured using a Calvet microcalorimeter. The ternary contribution to the excess enthalpy was correlated with the equation due to Morris et al. (1975) [15], and the equation proposed by Myers–Scott (1963) [14] was used to fitted the experimental binary mixture measured in this work. Additionally, the experimental results are compared with the estimations obtained by applying the group contribution model of UNIFAC, in the versions of Larsen et al. (1987) [16] and Gmehling et al. (1993) [17]. Several empirical expressions for estimating ternary properties from binary results were also tested

  2. Aqueous Solubility of Piperazine and 2-Amino-2-methyl-1-propanol plus Their Mixtures Using an Improved Freezing-Point Depression Method

    Fosbøl, Philip Loldrup; Neerup, Randi; Waseem Arshad, Muhammad; Tecle, Zacarias; Thomsen, Kaj

    2011-01-01

    In this work the solid–liquid equilibrium (SLE) and freezing-point depression (FPD) in the electrolytic binary aqueous systems piperazine (PZ, CAS No. 110-85-0) and aqueous 2-amino-2-methyl-1-propanol (AMP, CAS No. 124-68-5) were measured. The FPD and solubility were also determined in the ternar...

  3. A thermodynamic study of 1-propanol-glycerol-H2O at 25 degrees C: Effect of glycerol on molecular organization of H2O

    Parsons, M.T.; Westh, Peter; Davies, J.V.; Trandum, Christa; To, E.C.H.; Chiang, W.M.; Yee, E.G.M.; Koga, Y.

    2001-01-01

    The excess chemical potential, partial molar enthalpy, and volume of 1-propanol were determined in ternary mixtures of 1-propanol-glycerol-H2O at 25degreesC. The mole fraction dependence of all these thermodynamic functions was used to elucidate the effect of glycerol on the molecular organization...... of H2O. The glycerol molecules do not exert a hydrophobic effect on H2O. Rather, the hydroxyl groups of glycerol, perhaps by forming clusters via its alkyl backbone with hydroxyl groups pointing outward, interact with H2O so as to reduce the characteristics of liquid H2O. The global hydrogen bond...... probability and, hence, the percolation nature of the hydrogen bond network is reduced. In addition, the degree of fluctuation inherent in liquid H2O is reduced by glycerol perhaps by participating in the hydrogen bond network via OH groups. At infinite dilution, the pair interaction coefficients in enthalpy...

  4. Reprint of ''Quantitative NMR spectroscopy of binary liquid mixtures (aldehyde + alcohol). Part II: (Propanal or butanal or heptanal) + (methanol or ethanol or 1-propanol)''

    Highlights: • Formation of hemiacetal/poly(oxymethylene) hemiacetals in liquid binary mixtures. • Aldehyde (1-propanal or 1-butanal or 1-heptanal) and alcohol (methanol or ethanol or 1-propanol). • Quantitative 13C NMR spectroscopy at temperatures between (255 and 295) K. • High conversion rate to hemiacetals. • (1-Propanal + 1-propanol (50 + 50)) at 273 K: mole fraction of hemiacetal (polymers) ≈55% (≈6%). -- Abstract: The chemical reactions of aldehydes with alcohols to (hemiacetals and poly(oxymethylene) hemiacetals) have an essential influence on the thermodynamic properties and related phenomena like, for example, the vapor + liquid phase equilibrium of such liquid mixtures. This is well known in the literature for systems such as, for example, formaldehyde and methanol. Experimental information on the chemical reaction equilibria in mixtures with aldehydes other than formaldehyde and alcohols is extremely scarce. Therefore, in the first part of this series, quantitative NMR spectroscopy was used to investigate the chemical reaction equilibrium in binary liquid mixtures of acetaldehyde and an alcohol (methanol or ethanol or 1-propanol) at temperatures between (255 and 295) K. That work is here extended to three other aldehydes, viz. (1-propanal, 1-butanal and 1-heptanal). The results confirm the expectations from the first part of this series, i.e., that the majority of the constituents of the mixture is present as hemiacetal and the first two poly(oxymethylene) hemiacetals. For example, in an equimolar liquid mixture of {1-heptanal + methanol (or + ethanol or + 1-propanol)} at T = 273 K about 88% (or 81% for both other alcohols) of the aldehyde is bound to hemiacetal and the first two poly(oxymethylene) hemiacetals, i.e., the conversion rates are nearly the same as in the previous investigations with acetaldehyde instead of 1-heptanal. In the series investigated of combinations of aldehydes and alcohols, the particular aldehyde has only a small

  5. Viscosities and refractive indices of binary systems acetone+1-propanol, acetone+1,2-propanediol and acetone+1,3-propanediol

    Živković Emila M.

    2014-01-01

    Full Text Available Viscosities and refractive indices of three binary systems, acetone+1-propanol, acetone+1,2-propanediol and acetone+1,3-propanediol, were measured at eight temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15, 323.15K and at atmospheric pressure. From these data viscosity deviations and deviations in refractive index were calculated and fitted to the Redlich-Kister equation. The viscosity modelling was done by two types of models: predictive UNIFAC-VISCO and ASOG VISCO and correlative Teja-Rice and McAlister equations. The refractive indices of binary mixtures were predicted by various mixing rules and compared with experimental data. [Projekat Ministarstva nauke Republike Srbije, br. 172063

  6. Excess parameters for binary mixtures of ethyl benzoate with 1-propanol, 1-butanol and 1-pentanol at T=303, 308, 313, 318, and 323 K

    Sreehari Sastry, S.; Babu, Shaik; Vishwam, T.; Parvateesam, K.; Sie Tiong, Ha.

    2013-07-01

    Various thermo-acoustic parameters, such as excess isentropic compressibility (KsE), excess molar volume (VE), excess free length (LfE), excess Gibb's free energy (ΔG*E), and excess Enthalpy (HE), have been calculated from the experimentally determined data of density, viscosity and speed of sound for the binary mixtures of ethyl benzoate+1-propanol, or +1-butanol, or +1-pentanol over the entire range of composition at different temperatures (303, 308, 313, 318 and 323 K). The excess functions have been fitted to the Redlich-Kister type polynomial equation. The deviations for excess thermo-acoustic parameters have been explained on the basis of the intermolecular interactions present in these binary mixtures.

  7. Thermodynamic properties of solutions of sodium di-hydrogen phosphate in (1-propanol + water) mixed-solvent media over the temperature range of (283.15 to 303.15) K

    Sadeghi, Rahmat [Department of Chemistry, University of Kurdistan, Pasdran Street, Sanandaj, Kurdistan 66135 (Iran, Islamic Republic of)], E-mail: rsadeghi@uok.ac.ir; Parhizkar, Hana [Department of Chemistry, University of Kurdistan, Pasdran Street, Sanandaj, Kurdistan 66135 (Iran, Islamic Republic of)

    2008-06-15

    The apparent molar volume and apparent molar isentropic compressibility of solutions of sodium di-hydrogen phosphate (NaH{sub 2}PO{sub 4}) in (1-propanol + water) mixed-solvent media with alcohol mass fractions of 0.00, 0.05, 0.10, and 0.15 are reported over the range of temperature (283.15 to 303.15) K at 5 K intervals. The results were fitted to a Redlich-Mayer type equation from which the apparent molar volume and apparent molar isentropic compressibility of the solutions at the infinite dilution were also calculated at the working temperature. The results show a positive transfer volume of NaH{sub 2}PO{sub 4} from an aqueous solution to an aqueous 1-propanol solution. The apparent molar isentropic compressibility of NaH{sub 2}PO{sub 4} in aqueous 1-propanol solutions is negative and it increases with increasing the concentration of NaH{sub 2}PO{sub 4}, 1-propanol, and temperature. Electrical conductivity and refractive index of the solutions are also studied at T = 298.15 K. The effects of the electrolyte concentration and relative permittivity of the medium on the molar conductivity were also investigated.

  8. Excess molar volumes and viscosities of binary mixtures of some polyethers with 1-propanol at 288.15, 298.15, and 308.15 K

    Amalendu Pal; Anil Kumar

    2004-01-01

    Excess molar volumes ($V_{m}^{E}$) and viscosities () have been measured as a function of composition for binary liquid mixtures of 1-propanol, C3H7OH, with diethylene glycol diethyl ether (bis(2-ethoxyethyl)ether), C2H5(OC2H4)2OC2H5, and diethylene glycol dibutyl ether (bis(2-butoxyethyl)ether), C4H9(OC2H4)2OC4H9, at 288.15, 298.15, and 308.15 K and at atmospheric pressure. The excess volume results included the following mixing quantities at all range of concentrations and at equimolar concentrations: , volume expansivity; ( $V^{E}_{m}$/ ), and ( /) at 298.15 K. The obtained results were then compared with the calculated values by using the Flory theory of liquid mixtures. The theory predicts the values rather well, while the calculated values of ( $V^{E}_{m}$/ ) and ( /) show variation with alkyl chain length of the polyether. The results are discussed in terms of order or disorder creation. From the viscosity data, deviations in viscosity ( ) have been calculated. These values are negative over the entire range of composition. The results for $V^{E}_{m}$, and are discussed in terms of interaction between components.

  9. Evidence of the weakness of the OH⋯F hydrogen bond from a conformational study of 3-fluoro-1-propanol by microwave spectroscopy

    Caminati, Walther

    1982-03-01

    The rotational spectra of the OH and OD isotopic species have been observed for three rotamers of 3-fluoro-1-propanol. One of them (HBC form) displays an internal hydrogen bond with a distorted chair conformation of the six-membered ring. The other two rotamers have the oxygen atom gauche with respect to the C 2C 3 bond, the hydroxyl hydrogen trans with respect to the C 1C 2 bond and the fluorine atom gauche (GGT form) and trans (TGT form), respectively, with respect to the C 2C 1 bond. The energies of the vibrational ground states of the HBC and TGT forms are ˜0.4 and 1.0 kcal/mole higher than that of the GGT form, respectively (from relative intensity measurements). The hydrogen bond is therefore rather weak in this compound. With compounds capable of forming OH⋯O or OH⋯N bonds, the conformation appropriate for hydrogen bonding is normally the most stable form. Several excited states have been analyzed for the TGT and GGT rotamers in order to have additional data with respect to the potential function for the internal rotation about the C 3C 2 bond.

  10. Solvent structure effects on solvated electron reactions in mixed solvents: negative ions in 1-propanol-water and 2-propanol-water

    In models of the kinetics of chemical reactions in solution the solvent is commonly assumed to be a uniform continuum. An example is the Smoluchowski-Debye-Stokes-Einstein equation for the rate constant k2 of a bimolecular reaction between charged or polar species: k2 κRTfrr/1.5ηrd where κ = probability that a reactant encounter pair will react, R = gas constant, T = temperature, f = Coulombic interaction factor, rr = effective radius for reaction, η = solvent viscosity, and rd = effective radius for mutual diffusion. The equation is useful in evaluating effects of bulk-fluid properties on reaction rates. Residual effects are attributed to more specific solvent behaviour. Rate constants and activation energies E2 of reactions of solvated electrons es- with NO3- and CrOr2- ions vary with the composition of 1-propanol-water and 2-propanol-water mixed solvents. Plots of k2η/fT against solvent composition are nonlinear and change with solvent pair and with reactant pair. Measured molar conductivities Λ0(Li+, NO3-) and Λ0(2Li+, CrO42-) indicate the solvent dependence of rd for the mutual diffusion of Li+ and NO3- or CrO42-. The liquid structure influences both the rate of diffusion of the reactants and the probability of reaction of a reactant encounter pair. (author)

  11. D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol alters cellular cholesterol homeostasis by modulating the endosome lipid domains.

    Makino, Asami; Ishii, Kumiko; Murate, Motohide; Hayakawa, Tomohiro; Suzuki, Yusuke; Suzuki, Minoru; Ito, Kazuki; Fujisawa, Tetsuro; Matsuo, Hirotami; Ishitsuka, Reiko; Kobayashi, Toshihide

    2006-04-11

    D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP) is a frequently used inhibitor of glycosphingolipid biosynthesis. However, some interesting characteristics of D-PDMP cannot be explained by the inhibition of glycolipid synthesis alone. In the present study, we showed that d-PDMP inhibits the activation of lysosomal acid lipase by late endosome/lysosome specific lipid, bis(monoacylglycero)phosphate (also called as lysobisphosphatidic acid), through alteration of membrane structure of the lipid. When added to cultured fibroblasts, D-PDMP inhibits the degradation of low-density lipoprotein (LDL) and thus accumulates both cholesterol ester and free cholesterol in late endosomes/lysosomes. This accumulation results in the inhibition of LDL-derived cholesterol esterification and the decrease of cell surface cholesterol. We showed that D-PDMP alters cellular cholesterol homeostasis in a glycosphingolipid-independent manner using L-PDMP, a stereoisomer of D-PDMP, which does not inhibit glycosphingolipid synthesis, and mutant melanoma cell which is defective in glycolipid synthesis. Altering cholesterol homeostasis by D-PDMP explains the unique characteristics of sensitizing multidrug resistant cells by this drug. PMID:16584188

  12. Experimental and theoretical investigation of solubility of carbon dioxide in concentrated aqueous solution of 2-amino-2-methyl-1-propanol and piperazine

    Highlights: ► New VLE data of CO2 in aqueous 40 wt.% and 50 wt.% (AMP + PZ), experimental and modelling. ► Solid precipitation observed in 50 wt.% (AMP + PZ) below 318 K and at high loading. ► CO2 cyclic capacity of concentrated (AMP + PZ) at low CO2 partial pressure range. ► Relation among CO2 cyclic capacity, total solution molality and partial pressure. ► Model predicted heat capacity, pH and amine volatility of (CO2 + AMP + PZ + H2O) system. - Abstract: In this work, new experimental results for the (vapour + liquid) equilibrium (VLE) of CO2 in piperazine (PZ)-activated concentrated aqueous 2-amino-2-methyl-1-propanol (AMP) are presented for the temperature range of (303 to 328) K and PZ concentration range of (2 to 8) wt.%, keeping the total amine concentration in the solution at 40% and 50 wt.%. The partial pressures of CO2 are in the range of (0.2 to 1500) kPa. The electrolyte non-random two-liquid (ENRTL) theory has been used to develop the VLE model for the quaternary system (CO2 + AMP + PZ + H2O) to describe the equilibrium behaviour of the solution. The CO2 cyclic capacity of these solvents is determined between the rich and lean CO2 loadings. It is found that the CO2 cyclic capacity increases with the addition of PZ in aqueous AMP and also with the increase in AMP concentration in the aqueous solution. However, solid precipitation has been observed for 50 wt.% total amine concentration below T = 318 K for all relative compositions of AMP and PZ in the solvent at higher CO2 loading. The model results of equilibrium composition, pH of the loaded solution and amine volatility of the mixed solvent system, are also presented.

  13. Solubility and thermodynamic modeling of hydrogen sulfide in aqueous (diisopropanolamine + 2-amino-2-methyl-1-propanol + piperazine) solution at high pressure

    Highlights: • The (DIPA + AMP + Piperazine) systems are investigated. • A high pressure equilibrium cell is used for solubility measurement. • Piperazine improves H2S solubility in the (DIPA + AMP) system at high loading. • Electrolyte-NRTL is used for modeling of (H2S + DIPA + AMP + PZ) systems. - Abstract: Natural gas as a clean source of energy contains several contaminates such as CO2 and H2S that is treated through a natural gas purification unit in gas industry. Moreover, for design and construction of gas contactor equipment, it is necessary to obtain experimental values of solubility for H2S and CO2 in aqueous amine/alkanolamines. In this work, the solubility of H2S in the blended aqueous diisopropanolamine (DIPA), 2-amino-2-methyl-1-propanol (AMP) and piperazine (Pz) are measured using a static high pressure apparatus through volumetric method. The values are measured at fixed 45 mass per cent of total amine so that the solubility of H2S in the present system is investigated under isothermal conditions at T = (313.15, 328.15 and 343.15) K and in the pressure range of (0.1 to 2.1) MPa. The experimental results are presented as the partial pressure of H2S against acid gas loading (moles H2S per total moles of amine). Also for modeling the solubility of H2S in the blended amine/alkanolamines, the Electrolyte-NRTL activity coefficient function is applied to the correlation and prediction of the partial pressure of H2S versus the acid gas loading. Considering the present results at the given conditions, it is observed that in the low gas loading region, the effect of enhancing Pz on the solubility of H2S is very low, but at high gas loading the absorption of H2S is intensified by enhancing mass fraction of Pz in alkanolamine

  14. Excess enthalpies of ternary mixtures of (oxygenated additives + aromatic hydrocarbon) mixtures in fuels and bio-fuels: (Dibutyl-ether + 1-propanol + benzene), or toluene, at T = (298.15 and 313.15) K

    Highlights: • New excess enthalpy data for ternary mixtures of (dibutyl ether + aromatic hydrocarbon + 1-propanol) are reported. • 2 ternary systems at T = (298.15 and 313.15) K were measured by means of an isothermal flow calorimeter. • 230 data were fitted to a Redlich–Kister rational equation. • Intermolecular and association effects involved in these systems have been discussed. - Abstract: New experimental excess molar enthalpy data of the ternary systems (dibutyl ether + 1-propanol + benzene, or toluene), and the corresponding binary systems at T = (298.15 and 313.15) K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the binary and ternary systems show endothermic character at both temperatures. The experimental data for the systems have been fitted using the Redlich–Kister rational equation. Considerations with respect the intermolecular interactions amongst ether, alcohol and hydrocarbon compounds are presented

  15. Partial molar volumes of organic solutes in water. XII. Methanol(aq), ethanol(aq), 1-propanol(aq), and 2-propanol(aq) at T = (298 to 573) K and at pressures up to 30 MPa

    Density data for dilute aqueous solutions of methanol, ethanol, 1-propanol, and 2-propanol are presented together with partial molar volumes at infinite dilution calculated from the experimental data. The measurements were performed at from T = (298.15 up to 573.15) K and at pressure close to the saturated vapor pressure of water, at p = 30 MPa and at pressure between these limits. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter

  16. Excess molar enthalpies of ethylformate and (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) at T=(298.15 and 308.15)K and p=(5 and 10)MPa

    A high-pressure flow-mixing isothermal microcalorimeter is used to determine the excess molar enthalpies of five binary systems for ethylformate and (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) at T=(298.15 and 308.15) K and p=(5 and 10)MPa. The smooth values calculated by Redlich-Kister equation of HmE are also compared with the experimental results

  17. The buffering-out effect and phase separation in aqueous solutions of EPPS buffer with 1-propanol, 2-propanol, or 2-methyl-2-propanol at T = 298.15 K

    Highlights: ► Buffering-out is a new liquid–liquid phase separation containing biological buffer. ► EPPS buffer-induced phase separation of aqueous solutions of aliphatic alcohols. ► Phase diagrams of EPPS + water + 1-propanol/2-propanol/2-methyl-2-propanol are studied. ► EPPS breaks the 1-propanol + water and 2-methyl-2-propanol + water azeotropes. ► The (liquid + liquid) equilibria can be well correlated by the NRTL model. - Abstract: Buffering-out is a new liquid–liquid phase separation phenomenon observed in mixtures containing a buffer as a mass separating agent. The (liquid + liquid) equilibrium (LLE) and (solid + liquid + liquid) equilibrium (SLLE) data were measured for the ternary systems {3-[4-(2-hydroxyethyl)piperazin-1-yl]propanesulfonic acid (EPPS) buffer + 1-propanol, 2-propanol, or 2-methyl-2-propanol + water} at T = 298.15 K under atmospheric pressure. The phase boundary data were fitted to an empirical equation relating to the concentrations of organic solvent and buffer. The effective excluded volume (EEV) values of EPPS were obtained from the phase boundary data. The phase-separation abilities of the investigated aliphatic alcohols were discussed. The reliability of the experimental tie-lines was satisfactorily confirmed by the Othmer–Tobias correlation. The experimental tie-lines data for the ternary systems have been correlated using the NRTL activity coefficient model. The separation of these aliphatic alcohols from their azeotropic aqueous mixtures is of particular interest to industrial process. The addition of the EPPS as an auxiliary agent breaks the (1-propanol + water) and (2-methyl-2-propanol + water) azeotropes. The possibility of using the new phase separation systems in the extraction process is demonstrated by using different dyestuffs.

  18. Volumetric, transport, and acoustic properties of binary mixtures of 2-methyl-1-propanol with hexadecane and squalane at T = (298.15, 303.15, and 308.15) K: Experimental results, correlation, and prediction by the ERAS model

    Density ρ, speed of sound u, and viscosity η of the binary systems 2-methyl-1-propanol + hexadecane and 2-methyl-1-propanol + squalane (2,6,10,15,19,23-hexamethyltetracosane) have been measured over the entire range of composition at T = (298.15, 303.15, and 308.15) K and atmospheric pressure using a vibrating tube densimeter and sound analyzer Anton Paar model DSA-5000 and Ubbelohde suspended level viscometer. Excess molar volume VmE, excess molar isentropic compressibility KS,mE, and deviations of the speed of sound uD from their ideal values uid and excess thermal expansion coefficient αE were evaluated from the experimental results obtained. These derived properties were fitted to variable-degree polynomials. Further, the Extended Real Associated Solution (ERAS) model has been applied to VmE for the present binary mixtures along with (2-methyl-1-propanol + hexane, + octane and + decane) and the findings are compared with the experimental results.

  19. Densities and speeds of sound for binary mixtures of (1,3-dioxolane or 1,4-dioxane) with (2-methyl-1-propanol or 2-methyl-2-propanol) at the temperatures (298.15 and 313.15) K

    This paper reports densities and speeds of sound for the binary mixtures of (1,3-dioxolane or 1,4-dioxane) with (2-methyl-1-propanol or 2-methyl-2-propanol) at the temperatures (298.15 and 313.15) K. Excess volumes and excess isentropic compressibility coefficients have been calculated from experimental data and fitted by means of a Redlich-Kister type equation. The ERAS model has been used to calculate the excess volumes of the four systems at both temperatures

  20. Thermodynamics of mixtures containing amines. XIV. C{sub pm}{sup E} of benzylamine with heptane at 293.15 K or with methanol, 1-propanol or 1-pentanol at 293.15–308.15 K

    Páramo, Ricardo; Alonso, Víctor; González, Juan Antonio, E-mail: jagl@termo.uva.es; García de la Fuente, Isaías; Casanova, Carlos; Cobos, José Carlos

    2014-06-01

    Graphical abstract: - Highlights: • C{sub pm}{sup E}s are reported for benzylamine + heptane, +methanol, +1-propanol, +1-pentanol systems. • The heptane solution shows a W-shaped C{sub pm}{sup E} concentration dependence. • This reveals the existence of strong non-random effects in that mixture. • Systems with 1-alkanols are characterized by large and positive C{sub pm}{sup E} values. • This remarks that self-association/solvation effects are predominant in such systems. - Abstract: Molar excess heat capacities, C{sub pm}{sup E}, are reported for the benzylamine + heptane mixture at 293.15 K and for methanol, 1-propanol or 1-pentanol + benzylamine systems at 293.15–308.15 K. These values were determined from isobaric molar heat capacities obtained with a Setaram Micro DSC II microcalorimeter using a scanning method. The heptane solution shows a W-shaped C{sub pm}{sup E} concentration dependence, which reveals the existence of strong non-random effects. Systems including 1-alkanols are characterized by large and positive C{sub pm}{sup E} values. This remarks that self-association and/or solvation effects are predominant in such solutions. On the other hand, their C{sub pm}{sup E} curves are skewed towards higher mole fractions of the alcohol, which might be ascribed to the existence of more interactions between unlike molecules in that region.

  1. Experimental excess molar properties of binary mixtures of (3-amino-1-propanol + isobutanol, 2-propanol) at T = (293.15 to 333.15) K and modelling the excess molar volume by Prigogine–Flory–Patterson theory

    Highlights: ► Density and viscosity of binary mixtures of propanol derivatives were measured at T = (293.15 to 333.15) K. ► The excess molar properties were calculated from these experimental data and correlated by Redlich–Kister equation. ► The PFP model was applied for correlating the excess molar volumes. - Abstract: Density and viscosity of binary mixtures of (x13-amino-1-propanol + x2isobutanol) and (x13-amino-1-propanol + x22-propanol) were measured over the entire composition range and from temperatures (293.15 to 333.15) K at ambient pressure. The excess molar volumes and viscosity deviations were calculated and correlated by the Redlich–Kister (RK) equation. The thermal expansion coefficient and its excess value, isothermal coefficient of excess molar enthalpy, and excess partial molar volumes were determined by using the experimental values of density and are described as a function of composition and temperature. The excess molar volumes are negative over the entire mole fraction range for both mixtures and increase with increasing temperature. The excess molar volumes obtained were correlated by the Prigogine–Flory–Patterson (PFP) model. The viscosity deviations of the binary mixtures are negative over the entire composition range and decrease with increasing temperature.

  2. Measurement and modeling of densities and sound velocities of the systems [poly(propylene glycol)+methanol, +ethanol, +1-propanol, +2-propanol and +1-butanol] at T=298.15K

    Experiments have been performed at T=298.15K to measure the density and sound velocity of the systems [poly(propylene glycol)+methanol, +ethanol, +1-propanol, 2-propanol and +1-butanol] over the whole range of composition. From these measurements, values of the excess molar volume (Vmex) and excess molar isentropic compression, Ks,mex, equal to -(-bar Vmex/-bar p)s were calculated. The excess molar volume for all of these systems were found to be negative and decreases in magnitude as size of alcohol increases, except for 2-propanol solutions for which the magnitude of the excess volume is higher than that of 1-butanol solutions. Expressions for VmexandKs,mex of polymer solutions were obtained for the model of Flory-Huggins and the polymer non-random two liquid (NRTL) model. These expressions were used to fit the experimental VmexandKs,mex data of the investigated systems

  3. Dynamic and kinematic viscosities, excess volumes and excess Gibbs energies of activation for viscous flow in the ternary mixture {1- propanol+ N,N-dimethylformamide + chloroform} at temperatures between 293.15 K and 323.15 K

    Hassein-bey-Larouci, A., E-mail: hasseinbey@yahoo.fr [Laboratoire Thermodynamique et Modélisation Moléculaire, Faculté de Chimie, Université des Sciences et de la Technologie Houari Boumediene, B.P. 32, El-Alia, 16111 Bab-Ezzouar, Alger (Algeria); Igoujilen, O.; Aitkaci, A. [Laboratoire Thermodynamique et Modélisation Moléculaire, Faculté de Chimie, Université des Sciences et de la Technologie Houari Boumediene, B.P. 32, El-Alia, 16111 Bab-Ezzouar, Alger (Algeria); Segovia, J.J.; Villamañán, M.A. [TERMOCAL Research Group, Escuela de Ingenierías Industriales, Universidad de Valladolid, Paseo del Cauce, 59, 47011 Valladolid (Spain)

    2014-08-10

    Highlights: • Many engineering applications require quantitative thermodynamic data of the fluids. • Excess properties of mixtures are important in the understanding of mixing process. • The results are used to explain the molecular interaction in the mixtures. - Abstract: Dynamic and kinematic viscosities, and densities of the ternary mixture {x_1 propanol + x_2 DMF + x_3 chloroform} and of the three corresponding binary systems have been measured at 293.15, 303.15, 313.15 and 323.15 K and atmospheric pressure. The thermophysical properties, viscosity deviations (Δη), kinematic viscosity (γ), excess Gibbs energies of activation of viscous flow (G*{sup E}) and excess molar volumes (V{sup E}) have been calculated from experimental values of dynamic viscosity, η, and density, ρ. The different results have been correlated by the Redlich–Kister equation for the binary mixtures and the Cibulka equation for equation for the ternary ones.

  4. Densities and volumetric properties of (N-(2-hydroxyethyl)morpholine + ethanol, + 1-propanol, + 2-propanol, + 1-butanol, and + 2-butanol) at (293.15, 298.15, 303.15, 313.15, and 323.15) K

    Densities of binary mixtures of N-(2-hydroxyethyl)morpholine with ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol were measured over the entire composition range at temperatures from (293.15 to 323.15) K and atmospheric pressure using a vibrating-tube densimeter. The excess molar volumes, VE were calculated from density data and fitted to the Redlich-Kister polynomial equation. Apparent molar volumes, partial molar volume at infinite dilution and the thermal expansion coefficient of the mixtures were also calculated. The VE values were found to be negative over the entire composition range and at all temperatures studied and become less negative with increasing carbon chain length of the alkanols

  5. Dynamic and kinematic viscosities, excess volumes and excess Gibbs energies of activation for viscous flow in the ternary mixture {1- propanol+ N,N-dimethylformamide + chloroform} at temperatures between 293.15 K and 323.15 K

    Highlights: • Many engineering applications require quantitative thermodynamic data of the fluids. • Excess properties of mixtures are important in the understanding of mixing process. • The results are used to explain the molecular interaction in the mixtures. - Abstract: Dynamic and kinematic viscosities, and densities of the ternary mixture {x1 propanol + x2 DMF + x3 chloroform} and of the three corresponding binary systems have been measured at 293.15, 303.15, 313.15 and 323.15 K and atmospheric pressure. The thermophysical properties, viscosity deviations (Δη), kinematic viscosity (γ), excess Gibbs energies of activation of viscous flow (G*E) and excess molar volumes (VE) have been calculated from experimental values of dynamic viscosity, η, and density, ρ. The different results have been correlated by the Redlich–Kister equation for the binary mixtures and the Cibulka equation for equation for the ternary ones

  6. Spectroscopic investigations of new binuclear transition metal complexes of Schiff bases derived from 4,6-diacetylresorcinol and 3-amino-1-propanol or 1,3-diamino-propane

    Emara, Adel A. A.; Saleh, Akila A.; Adly, Omima M. I.

    2007-11-01

    The bifunctional carbonyl compound; 4,6-diacetylresorcinol (DAR) serves as precursor for the formation of different Schiff base ligands, which are either di- or tetra-basic with two symmetrical sets of either O 2N or N 2O tridentate chelating sites. The condensation of 4,6-diacetylresorcinol with 3-amino-1-propanol (3-AP) or 1,3-diaminopropane (DAP), yields the corresponding hexadentate Schiff base ligands, abbreviated as H 4L a and H 2L b, respectively. The structures of these ligands were elucidated by elemental analyses, IR, mass, 1H NMR and electronic spectra. Reaction of the Schiff base ligands with copper(II), nickel(II), cobalt(II), zinc(II), cadmium(II), iron(III), chromium(III), vanadyl(IV) and uranyl(VI) ions in 1:2 molar ratio afforded the corresponding transition metal complexes. A variety of binuclear complexes for the metal complexes were obtained with the ligands in its di- or tetra-deprotonated forms. The structures of the newly prepared complexes were identified by elemental analyses, infrared, electronic, mass, 1H NMR and ESR spectra as well as magnetic susceptibility measurements and thermal gravimetric analysis (TGA). The bonding sites are the azomethine and amino nitrogen atoms, and phenolic and alcoholic oxygen atoms. The metal complexes exhibit different geometrical arrangements such as square planar, tetrahedral, square pyramid and octahedral arrangement.

  7. Excess molar enthalpies of {diethyl oxalate + (methanol, + ethanol, + 1-propanol, and + 2-propanol)} at T = (288.2, 298.2, 313.2, and 328.2) K and p = 101.3 kPa

    Highlights: • The excess molar enthalpies for four binary systems of diethyl oxalate + alcohols were determined. • The densities of the diethyl oxalate at different temperature were measured. • The excess molar enthalpies increase with temperature and the molecular size of the alcohols. • The experimental data were correlated by two local-composition models (NRTL and UNIQUAC). -- Abstract: A flow-mixing isothermal microcalorimeter was used to measure excess molar enthalpies for four binary systems of {diethyl oxalate + (methanol, + ethanol, + 1-propanol, and + 2-propanol)} at T = (288.2, 298.2, 313.2, and 328.2) K and p = 101.3 kPa. The densities of the diethyl oxalate at different temperature were measured by using a vibrating-tube densimeter. All systems exhibit endothermic behaviour over the whole composition range, which means that the rupture of interactions is energetically the main effect. The excess molar enthalpies increase with temperature and the molecular size of the alcohols. The experimental results were correlated by using the Redlich–Kister equation and two local-composition models (NRTL and UNIQUAC)

  8. Apparent molar volumes and apparent molar heat capacities of dilute aqueous solutions of ethanol, 1-propanol, and 2-propanol at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa

    Apparent molar volumes Vphi and apparent molar heat capacities Cp,phi have been determined for dilute aqueous solutions of ethanol, 1-propanol, and 2-propanol at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa. The molalities investigated ranged from 0.05 mol·kg-1 to 1.0 mol·kg-1. We used a vibrating tube densimeter (DMA 512P, Anton PAAR, Austria) to determine the densities and volumetric properties. Heat capacities were obtained using a twin fixed-cell, power-compensation, differential-output, temperature-scanning calorimeter (NanoDSC 6100, Calorimetry Sciences Corporation, American Fork, UT, USA). The results were fit by regression to equations that describe the surfaces (Vphi,T,m) and (Cp,phi,T,m). Infinite dilution partial molar volumes V20 and heat capacities C0p,2 were obtained over the range of temperatures by extrapolation of these surfaces to m=0 mol·kg-1

  9. Excess molar enthalpies and excess molar volumes of formamide + 1-propanol or 2-propanol and thermodynamic modeling by Prigogine–Flory–Patterson theory and Treszczanowicz–Benson association model

    Highlights: ► Measured HmE and VmE data of formamide + propanol were interpreted in terms of PFP theory. ► Treszczanowicz–Benson association model was also applied to these binary systems. ► The calculated HmE and VmE values compared well with corresponding experimental data. ► Extent of H-bonding in formamide and propanol in their mixture was reflected in ΔhH0 and KH. - Abstract: Excess molar enthalpies (HmE) at 298.15 K and 308.15 K and excess molar volumes (VmE) at 308.15 K for formamide (1) + 1-propanol or 2-propanol (2) mixtures have been measured over the entire composition range. The excess enthalpies and excess volumes data have been utilized to study the thermodynamics of molecular interactions in terms of Prigogine–Flory–Patterson theory and Treszczanowicz–Benson association model with a Flory contribution term. In this paper, this Treszczanowicz–Benson association model was applied, for the first time, to binary mixtures containing both components associated (propanol and formamide) through hydrogen bonding. In both the cases, when either of formamide or propanol was assumed to be associated, the calculated HmE and VmE values compared well with corresponding experimental data. Extent of inter-molecular H-bonding in formamide and propanol in their binary mixtures was also reflected in their molar enthalpy of association of H-bonding ΔhH0 and association constant KH

  10. Enthalpy of absorption and limit of solubility of CO2 in aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol, 2-[2-(dimethyl-amino)ethoxy] ethanol, and 3-dimethyl-amino-1-propanol at T = (313.15 and 353.15) K and pressures up to 2 MPa

    In order to study the influence of amine structure on absorption of carbon dioxide, enthalpies of solution of CO2 in 2.50 mol . L-1 aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol (THAM), 2-[2-(dimethyl-amino)ethoxy] ethanol (DMAEOE), and 3-dimethyl-amino-1-propanol (DMAP) were measured. The enthalpies of solution are determined as function of gas loading charge (moles of CO2/mole of amine), at temperatures (313.15 and 353.15) K, and pressures range from (0.5 to 2) MPa. Measurements were carried out using a flow calorimetric technique. CO2 solubilities in the aqueous solutions of amine are derived from calorimetric data. Molar volumes of aqueous amine solutions required to handle calorimetric data were determined at 303.15 K using a vibrating tube densimeter. Experimental enthalpies of solution are discussed on the basis of amines alkalinity.

  11. Enthalpy of absorption and limit of solubility of CO{sub 2} in aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol, 2-[2-(dimethyl-amino)ethoxy] ethanol, and 3-dimethyl-amino-1-propanol at T = (313.15 and 353.15) K and pressures up to 2 MPa

    Rodier, Laurence; Ballerat-Busserolles, Karine [Clermont Universite, Universite Blaise Pascal, Laboratoire de Thermodynamique et Interactions Moleculaires, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6272, Laboratoire de Thermodynamique et Interactions Moleculaires, F-63173 Aubiere (France); Coxam, Jean-Yves, E-mail: j-yves.coxam@univ-bpclermont.f [Clermont Universite, Universite Blaise Pascal, Laboratoire de Thermodynamique et Interactions Moleculaires, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6272, Laboratoire de Thermodynamique et Interactions Moleculaires, F-63173 Aubiere (France)

    2010-06-15

    In order to study the influence of amine structure on absorption of carbon dioxide, enthalpies of solution of CO{sub 2} in 2.50 mol . L{sup -1} aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol (THAM), 2-[2-(dimethyl-amino)ethoxy] ethanol (DMAEOE), and 3-dimethyl-amino-1-propanol (DMAP) were measured. The enthalpies of solution are determined as function of gas loading charge (moles of CO{sub 2}/mole of amine), at temperatures (313.15 and 353.15) K, and pressures range from (0.5 to 2) MPa. Measurements were carried out using a flow calorimetric technique. CO{sub 2} solubilities in the aqueous solutions of amine are derived from calorimetric data. Molar volumes of aqueous amine solutions required to handle calorimetric data were determined at 303.15 K using a vibrating tube densimeter. Experimental enthalpies of solution are discussed on the basis of amines alkalinity.

  12. Henry's law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol

    Henry's law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol in the temperature range of 250 K to 330 K were measured by a gas stripping method and partial molar excess enthalpies were calculated from the activity coefficients. A rigorous formula for evaluating the Henry's law constants from the gas stripping measurements was used for the data reduction of these highly volatile mixtures. The uncertainty is about 2% for the Henry's law constants and 3% for the estimated infinite dilution activity coefficients. In the evaluation of the infinite dilution activity coefficients, the nonideality of the solute such as the fugacity coefficient and Poynting correction factor cannot be neglected, especially at higher temperatures. The estimated uncertainty of the infinite dilution activity coefficients includes 1% for nonideality

  13. [Bim]Ac离子液体+醇二元混合体系的体积和黏度性质研究%Volumetric and Viscosity Properties of 1-Butylimidazolium Acetate Ionic Liquid/Methanol, Ethanol or 1-Propanol Binary Mixtures

    许映杰; 俞超红; 鲁越青

    2015-01-01

    1-Butylimidazolium acetate ([Bim]Ac) ionic liquid was synthesized, and the structure was characterized by1H-NMR,13C-NMR, and IR spectroscopy. Density and viscosity of [Bim]Ac+methanol, [Bim]Ac+ethanol, and [Bim]Ac+1-propanol binary mixtures were measured over an entire range of molar fraction at T=303.15 K under atmospheric pressure using a vibrating U-shaped sample tube densimeter and Ubbelohde Suspended-level viscometer, respectively. Excess molar volumes (VE), apparent molar volumes (Vfi), partial molar volumes (Vm,i), and excess partial molar volumes (VEm,i) of the studied systems were calculated with the density data. Viscosity deviations (Δη) of the studied systems were obtained from the viscosity data.VE andΔηwere fitted by Redlich-Kister equation, respectively. The results show that theVE values of the three studied systems are negative over the entire composition range, and a minimum value is reached with mole fraction of [Bim]Acx1=0.3~0.4. TheΔηvalues of the above-mentioned systems are also negative over the entire composition range, and a minimum value is reached withx1=0.4~0.5. TheVE orΔη values of the studied systems follow an order of [Bim]Ac+methanol < [Bim]Ac+ethanol < [Bim]Ac+1-propanol, which indicates that the interaction between [Bim]Ac and alkanol increases with the increase of alkanol polarity. TheVE andΔη values can be well fitted with Redlich-Kister equation.%合成了1-丁基咪唑醋酸盐([Bim]Ac)离子液体,通过1H-NMR、13C-NMR和IR对其结构进行了表征。在303.15 K和常压下,采用U形振荡管密度计测定了[Bim]Ac+甲醇、乙醇和正丙醇二元体系的密度,用乌氏黏度计测定了体系的黏度。由密度数据计算得到了体系的超额摩尔体积(VE)、表观摩尔体积(Vfi )、偏摩尔体积(V m,i )和超额偏摩尔体积( EV m,i ),由黏度数据获得了体系的混合黏度变化(∆h),并采用Redlich-Kister方程分别关联了VE、∆h与组成的关系。结果表明:

  14. Regeneration of 2-amino-2-methyl-1-propanol used for carbon dioxide absorption

    2008-01-01

    To improve the efficiency of the carbon dioxide cycling process and to reduce the regeneration energy consumption, a sterically hindered amine of 2-amino-2-methyl-1- propranol (AMP) was investigated to determine its regeneration behavior as a CO2 absorbent. The CO2 absorption and amine regeneration characteristics were experimentally examined under various operating conditions. The regeneration efficiency increased from 86.2% to 98.3% during the temperature range of 358 K to 403 K. The most suitable regeneration temperature for AMP was 383 K, in this experiment condition, and the regeneration efficiency of absorption/regeneration runs descended from 98.3% to 94.0%. A number of heat-stable salts (HSS) could cause a reduction in CO2 absorption capacity and regeneration efficiency. The results indicated that aqueous AMP was easier to regenerate with less loss of absorption capacity than other amines, such as, monoethanolamine (MEA), diethanolamine (DEA), diethylenetriamine (DETA), and N-methyldiethanolamine (MDEA).

  15. Density measurements under pressure for the binary system 1-propanol plus toluene

    Zeberg-Mikkelsen, Claus Kjær; Andersen, Simon Ivar

    2005-01-01

    seven isobars up to 30 MPa. The uncertainty of the reported densities is less than 0.05%. The measured data has been used to study the influence of temperature, pressure, and composition on the isothermal compressibility and the isobaric thermal expansivity as well as the excess molar volume, which...

  16. PIV Measurement of Transient 3-D (Liquid and Gas Phases) Flow Structures Created by a Spreading Flame over 1-Propanol

    Hassan, M. I.; Kuwana, K.; Saito, K.

    2001-01-01

    In the past, we measured three-D flow structure in the liquid and gas phases that were created by a spreading flame over liquid fuels. In that effort, we employed several different techniques including our original laser sheet particle tracking (LSPT) technique, which is capable of measuring transient 2-D flow structures. Recently we obtained a state-of-the-art integrated particle image velocimetry (IPIV), whose function is similar to LSPT, but it has an integrated data recording and processing system. To evaluate the accuracy of our IPIV system, we conducted a series of flame spread tests using the same experimental apparatus that we used in our previous flame spread studies and obtained a series of 2-D flow profiles corresponding to our previous LSPT measurements. We confirmed that both LSPT and IPIV techniques produced similar data, but IPIV data contains more detailed flow structures than LSPT data. Here we present some of newly obtained IPIV flow structure data, and discuss the role of gravity in the flame-induced flow structures. Note that the application of IPIV to our flame spread problems is not straightforward, and it required several preliminary tests for its accuracy including this IPIV comparison to LSPT.

  17. Comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin and the Hawaiian marine algae, Chaetoceros, for potential broad-spectrum control of anaerobically grown lactic acid bacteria

    The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen and may also contain foodborne or opportunistic human pathogens as well as bacteria capable of causing mastitis in cows. Thus, there is a need to develop broad-spectrum therapies that are effecti...

  18. Effects of constituent ions of a phosphonium-based ionic liquid on molecular organization of H2O as probed by 1-propanol

    Morita, Takeshi; Miki, Kumiko; Ayako, Nitta; Ohgi, Hiroyo; Westh, Peter

    2015-01-01

    Aqueous solutions of tetrabutylphosphonium trifluoroacetate, [P4444]CF3COO, exhibit a liquid-liquid phase transition with a lower critical solution temperature. Herein, we characterized the constituent ions, [P4444](+) and CF3COO(-), in terms of their effects on the molecular organization of H2O on...... typical imidazolium-based cation, [C4mim](+). Self-aggregation of [P4444](+) was found to occur in an aqueous solution of [P4444]CF3COO above 0.0080 mole fraction of the IL....

  19. In vitro comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin(R), and the Hawaiian marine algae, Chaetoceros, activity against anaerobically grown Staphylococcus aureus

    Mastitis is a common illness of dairy cattle and is very costly, economically, to the dairy farmer. Thus, there is a need to develop broad-spectrum therapies that are effective while not leading to unacceptably long antibiotic withdrawal times. The effects of the CH4-inhibitors nitroethane (2 mg/m...

  20. Thermodynamic and acoustical properties of mixtures p-anisaldehyde—alkanols (C1-C4)—2-methyl-1-propanol at 303.15 K

    Saini, Balwinder; Kumar, Ashwani; Rani, Ruby; Bamezai, Rajinder K.

    2016-07-01

    The density, viscosity and speed of sound of pure p-anisaldehyde and some alkanols, for example, methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, and the binary mixtures of p-anisaldehyde with these alkanols were measured over the entire composition range at 303.15 K. From the experimental data, various thermodynamic parameters such as excess molar volume ( V E), excess Gibbs free energy of activation (Δ G*E), and deviation parameters like viscosity (Δη), speed of sound (Δ u), isentropic compressibility (Δκs), are calculated. The excess as well as deviation parameters are fitted to Redlich—Kister equation. Additionally, the viscosity data for the systems has been used to correlate the application of empirical relation given by Grunberg and Nissan, Katti and Chaudhari, and Hind et al. The results are discussed in terms of specific interactions present in the mixtures.

  1. Interaction of some hydrophobic amino acids, peptides, and protein with aqueous 3-chloro-1,2-propanediol and 3-chloro-1-propanol: Biophysical studies

    Keswani, Neelam [Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India); Kishore, Nand, E-mail: nandk@chem.iitb.ac.i [Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India)

    2011-04-15

    Research highlights: Thermodynamic properties of amino acids, peptides and protein determined in solution. The solvents chosen were 3-chloropropan-1-ol and 3-chloropropan-1,2-diol. {yields}The results enabled understanding the interactions quantitatively in these systems affecting the protein stability. Fine details of interactions provided in-depth analysis. - Abstract: The apparent molar volume V{sub 2,{phi},} apparent molar isentropic compressibility K{sub S,2,{phi},} and heat of dilution (q) of aqueous glycine, alanine, {alpha}-amino butyric acid, valine, leucine, diglycine, triglycine, and hen egg white lysozyme have been determined in aqueous solutions of 3-chloropropano-1-ol and 3-chloropropan-1,2-diol solutions at T = 298.15 K. These data have been used to calculate the infinite dilution standard partial molar volume V{sub 2,m}{sup 0}, partial molar isentropic compressibility K{sub S,2,m}{sup 0}, and enthalpy of dilution {Delta}{sub dil}H{sup o} of the amino acids and peptides in aqueous 3-chloropropano-1-ol and 3-chloropropan-1,2-diol, and the standard partial molar quantities of transfer of the amino acids and peptides to the aqueous alcohol and diol solutions. The linear correlation of V{sub 2,m}{sup 0} for a homologous series of amino acids has been utilized to calculate the contribution of the charged end groups (NH{sub 3}{sup +},COO{sup -}), CH{sub 2} group and other alkyl chains of the amino acids to the values of V{sub 2,m}{sup 0}. The results on the standard partial molar volumes of transfer, compressibility and enthalpy of dilution from water to aqueous alcohol and diol solutions have been correlated and interpreted in terms of ion-polar, ion-hydrophobic, and hydrophobic-hydrophobic group interactions. The heat of dilution of these amino acids, peptides, and hen egg white lysozyme measured in aqueous solutions of 3-chloropropano-1-ol and 3-chloropropan-1,2-diol by using isothermal titration calorimetry along with the volumetric, compressibility, and calorimetric results on amino acid and peptides have been correlated to understand the nature of interactions operating in these systems.

  2. In vitro comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin(R), and the Hawaiian marine algae, Chaetoceros, activity against anaerobically grown Staphylococcus aureus

    The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen and may also contain foodborne or opportunistic human pathogens as well as causative agents of mastitis in cows. Thus, there is a need to develop broad-spectrum therapies that are effective while...

  3. 超临界正丙醇回收炭纤维增强环氧树脂复合材料%Recycling of carbon fibers in epoxy resin composites using supercritical 1-propanol

    严华; 吕春祥; 经德齐; 常春报; 刘纳新; 侯相林

    2016-01-01

    研究了降解温度、反应时间和添加剂对超临界正丙醇中炭纤维增强环氧树脂基复合材料回收的影响.利用扫描电镜、热重、X射线光电子能谱、接触角和单丝拉伸对回收炭纤维进行表征.结果表明,随温度的升高,复合材料降解速率加快,但回收炭纤维力学性能略微降低.随反应时间的延长,复合材料降解速率降低,回收炭纤维力学性能降低.1%质量含量的KOH能明显提高复合材料的回收效率.伴随KOH含量增加,复合材料降解速率没有明显提高,而使回收炭纤维力学性能变差.合适的反应条件对回收具有清洁表面、良好热稳定性和力学性能完好保留的炭纤维至关重要.回收炭纤维表面化学的微弱变化使回收炭纤维同环氧树脂的接触角略增加.超临界正丙醇是一种回收炭纤维复合材料的有效方法.

  4. 1,2-Oxathiolane - A Photoelectron Spectroscopic Study

    Jørgensen, F. S.; Carlsen, Lars

    1983-01-01

    Der cyclische Sulfensureester 1,2-Oxathiolan (1) wurde durch milde Thermolyse von 3-(Phthalimidothio)-1-propanol (2) gewonnen und durch Photoelektronen-Spektroskopie identifiziert.- Die Möglichkeiten zur photoelektronenspektroskopischen Bestimmung der Konformation von Sulfensureestern werden...

  5. Volumetric properties of binary mixtures of ionic liquid 1-butyl-3-methylimidazolium octylsulfate with water or propanol in the temperature range of 278.15K to 328.15K

    Densities of 1-butyl-3-methylimidazolium octylsulfate ([bmim][OcOSO3]) solutions in water and 1-propanol have been measured with an oscillating-tube densimeter at temperatures from 278.15K to 328.15K. From these densities, apparent molar volumes Vφ of [bmim][OcOSO3] in both solvents have been calculated, and its dependence on the molality has been treated with the Redlich and Meyer equation. Debye-Huckel limiting slopes for 1-propanol at working temperatures have been calculated, and apparent molar volumes of [bmim][OcOSO3] at infinite dilution Vφo in both solvents have been evaluated. The partial molar volume at infinite dilution of [bmim][OcOSO3] in water is higher than in 1-propanol and augments when the temperature augments. On the other hand, the partial molar volume at infinite dilution of [bmim][OcOSO3] in 1-propanol decreases when the temperature augments

  6. Characterization of volatile compounds of “Drenja”, an alcoholic beverage obtained from the fruits of cornelian cherry

    VELE TEŠEVIĆ; NINOSLAV NIKIĆEVIĆ; SLOBODAN MILOSAVLJEVIĆ; DANICA BAJIĆ; VLATKA VAJS; IVAN VUČKOVIĆ; LJUBODRAG VUJISIĆ; IRIS ĐORĐEVIĆ; MIROSLAVA STANKOVIĆ; MILOVAN VELIČKOVIĆ

    2009-01-01

    In this study, volatile compounds were analyzed in five samples of home-made spirit beverage made by the distillation of fermented fruits of cornelian cherry (Cornus mas L.). The major volatile compounds, besides ethanol, identified and quantified were: methanol, acetaldehyde, 1-propanol, ethyl acetate, 2-methyl-1-propanol, 1-butanol, amyl alcohols, 1-hexanol and 2-phenylethanol. The minor volatiles were submitted to liquid–liquid extraction with dichloromethane and analyzed by gas chromatogr...

  7. Measurement and correlation of solubility of Tetracycline hydrochloride in six organic solvents

    Highlights: ► The solubility of Tetracycline hydrochloride (TCH) in six organic solvents was determined. ► Apelblat, NRTL and UNIQUAC models were used to correlate the experimental data. ► Superior correlation was achieved with NRTL model. - Abstract: The solubility of Tetracycline hydrochloride (TCH) in methanol, ethanol, 1-propanol, 1-butanol, acetone, and acetonitrile, was measured using a static method from (283.15 to 318.15) K. The solubility of TCH decreased in the order of methanol, ethanol, 1-propanol, 1-butanol, acetone, and acetonitrile. With increasing temperature, the solubility of TCH increased in ethanol, 1-propanol, 1-butanol, acetone, and acetonitrile but decreased in methanol. Moreover, the experimental solubility data were correlated by the modified Apelblat equation, NRTL and UNIQUAC models, respectively. And the calculated data by NRTL model showed better agreement with experimental values than the modified Apelblat equation and UNIQUAC model.

  8. Measurement and correlation of critical properties for binary mixtures and ternary mixtures containing gasoline additives

    Highlights: • A high-pressure view cell was used to measure the critical properties of mixtures. • Three binary mixtures’ and three ternary mixtures’ critical properties were reported. • The experimental data of each system covered the whole mole fraction range. • The critical properties of the ternary mixtures were predicted with the PR–WS model. • Empirical equations were used to correlate the experimental results. - Abstract: The critical properties of three binary mixtures and three ternary mixtures containing gasoline additives (including methanol + 1-propanol, heptane + ethanol, heptane + 1-propanol, methanol + 1-propanol + heptane, methanol + 1-propanol + methyl tert-butyl ether (MTBE), and ethanol + heptane + MTBE) were determined by a high-pressure cell. All the critical lines of binary mixtures belong to the type I described by Scott and van Konynenburg. The system of methanol + 1-propanol showed little non-ideal behavior due to their similar molecular structures. The heptane + ethanol and heptane + 1-propanol systems showed visible non-ideal behavior for their great differences in molecular structure. The Peng–Robinson equation of state combined with the Wong–Sandler mixing rule (PR–WS) was applied to correlate the critical properties of binary mixtures. The critical points of the three ternary mixtures were predicted by the PR–WS model with the binary interaction parameters using the procedure proposed by Heidemann and Khalil. The predicted critical temperatures were in good agreement with the experimental values, while the predicted critical pressures differed from the measured values. The experimental values of binary mixtures were fitted well with the Redlich–Kister equation. The critical properties of ternary mixtures were correlated with the Cibulka’s equation, and the critical surfaces were plotted using the Cibulka’s equations

  9. Solubility of pyrene in binary alcohol + cyclohexanol and alcohol + 1-pentanol solvent mixtures at 299.2 K

    McHale, M.E.R.; Horton, A.S.M.; Padilla, S.A.; Trufant, A.L.; De La Sancha, N.U.; Vela, E.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1996-11-01

    Experimental solubilities are reported for pyrene dissolved in five binary alcohol + cyclohexanol and seven binary alcohol + 1-pentanol solvent mixtures at 26 C. Alcohol cosolvents include 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol, and 2-pentanol. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the 12 systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being on the order of 0.5%.

  10. Solubility of anthracene in binary alcohol + 2-methoxyethanol solvent mixtures

    McHale, M.E.R.; Powell, J.R.; Kauppila, A.S.M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1996-01-01

    Experimental solubilities are reported for anthracene dissolved in seven binary mixtures containing 2-methoxyethanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-octanol, 2-methyl-1-propanol, and 3-methyl-1-butanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined Nearly Ideal Binary Solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the seven systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being on the order of 0.5%.

  11. Phase equilibrium in systems with ionic liquids: An example for the downstream process of the Biphasic Acid Scavenging utilizing Ionic Liquids (BASIL) process. Part I: Experimental data

    Highlights: ► Phase equilibrium for a downstream process in sustainable chemical technology. ► Biphasic Acid Scavenging Utilizing Ionic Liquids (BASIL) Process. ► SLE, LLE, and SLLE of (NaCl + water + 1-propanol + 1-MIM) and its ternary subsystems. ► Experimental phase equilibrium data at temperatures between 298 K and 333 K. - Abstract: Experimental results are presented for the (liquid + liquid), (solid + liquid) and (solid + liquid + liquid) equilibria occurring in the downstream process of a typical example for the Biphasic Acid Scavenging Utilizing Ionic Liquids (BASIL)-processes. In a BASIL process an organic base is used to catalyze a chemical reaction and, at the same time, to scavenge an acid that is an undesired side product of that reaction. The particular example of a BASIL process treated here is the reaction of 1-butanol and acetylchloride to butylacetate and hydrochloric acid, where the acid is scavenged by the organic base 1-methyl imidazole (1-MIM) resulting in the ionic liquid 1-methyl imidazolium chloride. The reaction results in a two-phase system as butylacetate and the ionic liquid reveal a large liquid–liquid miscibility gap. The organic base has to be recovered. This is commonly achieved by treating the ionic liquid–rich liquid phase with an aqueous solution of sodium hydroxide (i.e., converting the ionic liquid to the organic base) and extracting the organic base by an appropriate organic solvent (e.g., 1-propanol). The work presented here deals in experimental work with the (liquid + liquid), (solid + liquid) and (solid + liquid + liquid) phase equilibria that are encountered in such extraction processes. Experimental results are reported for temperatures between about 298 K and 333 K: for the solubility of NaCl in several solvents (1-propanol, 1-MIM), (water + 1-MIM), (1-propanol + 1-MIM), (water + 1-propanol), and (water + 1-propanol + 1-MIM) and for the (liquid + liquid) equilibrium as well as for the (solid + liquid

  12. Regioselective alkane hydroxylation with a mutant AlkB enzyme

    Koch, Daniel J.; Arnold, Frances H.

    2012-11-13

    AlkB from Pseudomonas putida was engineered using in-vivo directed evolution to hydroxylate small chain alkanes. Mutant AlkB-BMO1 hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. Mutant AlkB-BMO2 similarly hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. These biocatalysts are highly active for small chain alkane substrates and their regioselectivity is retained in whole-cell biotransformations.

  13. Synergic effects in the extraction of paracetamol from aqueous NaCl solution by the binary mixtures of diethyl ether and low molecular weight primary alcohols

    Nikolić, G. M.; Živković, J. V.; Atanasković, D. S.; Nikolić, M. G.

    2013-12-01

    Liquid-liquid extraction of paracetamol from aqueous NaCl solutions was performed with diethyl ether, 1-propanol, 1-butanol, isobutanol, 1-pentanol, and binary mixtures diethyl ether/1-propanol, diethyl ether/1-butanol, and diethyl ether/isobutanol. Among the pure solvents investigated in this study best extraction efficacy was obtained with 1-butanol. Synergic effects in the extraction with binary mixtures was investigated and compared with some other systems used for the extraction of poorly extractable compounds. Results obtained in this study may be of both fundamental and practical importance.

  14. Effects of select nitrocompounds on in vitro ruminal fermentation during conditions of limiting or excess added reductant

    Ruminal methane (CH4) production results in losses of up to 12% of gross energy intake and contributes nearly 20% of the United States’ annual emission of this greenhouse gas. We report the effects of 2-nitro-1-propanol (NPOH), 3-nitro-1-propionic acid (NPA), nitroethane (NE) and 2-nitroethanol (NE...

  15. Use of isothermal titration calorimetry to study the interaction of short-chain alcohols with lipid membranes

    Trandum, Christa; Westh-Andersen, Peter; Jørgensen, Kent; Mouritsen, Ole G.

    ganglioside (GM(1)) were investigated at temperatures above, and below, the main phase-transition temperature of DMPC. The alcohols used were ethanol, 1-propanol, and 1-butanol. The calorimetric results reveal that the interaction of short-chain alcohols with the lipid bilayer is endothermic and strongly...

  16. The Mobile Phase Motion in Ascending Micellar Thin-Layer Chromatography with Normal-Phase Plates

    Boichenko, Alexander P.; Makhno, Iryna V.; Renkevich, Anton Yu.; Loginova, Lidia P.

    2011-01-01

    The physical chemical characteristics (surface tension and viscosity) of micellar mobile phases based on the cationic surfactant cetylpiridinium chloride and additives of alcohols (ethanol, 1-propanol, 1-butanol, 1-pentanol) have been obtained in this work. The effect of mobile phase properties on t

  17. Significance of volatile compounds produced by spoilage bacteria in vacuum-packed cold-smoked salmon ( Salmo salar ) analyzed by GC-MS and multivariate regression

    Jørgensen, Lasse Vigel; Huss, Hans Henrik; Dalgaard, Paw

    2001-01-01

    , 1- penten-3-ol, and 1-propanol. The potency and importance of these compounds was confirmed by gas chromatography- olfactometry. The present study provides valuable information on the bacterial reactions responsible for spoilage off-flavors of cold-smoked salmon, which can be used to develop...

  18. Cluster formation restricts dynamic nuclear polarization of xenon in solid mixtures

    Kuzma, N. N.; Pourfathi, M.; Kara, H.;

    2012-01-01

    During dynamic nuclear polarization (DNP) at 1.5 K and 5 T, Xe-129 nuclear magnetic resonance (NMR) spectra of a homogeneous xenon/1-propanol/trityl-radical solid mixture exhibit a single peak, broadened by H-1 neighbors. A second peak appears upon annealing for several hours at 125 K. Its...

  19. Selective Adsorption of Water from Mixtures with 1-Alcohols by Exploitation of Molecular Packing Effects in CuBTC

    J.J. Gutiérrez-Sevillano; S. Calero; R. Krishna

    2015-01-01

    The selective removal of water from mixtures with methanol, ethanol, and 1-propanol is an important task in the processing industries. With the aid of configurational-bias Monte Carlo simulations of unary and mixture adsorption, we establish the potential of CuBTC for this separation task. For opera

  20. Solubility of anthracene and pyrene in binary alcohol + alcohol solvent mixtures

    Zvaigzne, A.I.; McHale, M.E.R.; Powell, J.R.; Kauppila, A.S.M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1995-11-01

    Solid-liquid equilibrium data of organic nonelectrolyte systems are becoming increasingly important in the petroleum industry, particularly in light of present trends toward heavier feedstocks and known carcinogenicity/mutagenicity of many of the larger polycyclic aromatic compounds. Experimental solubilities are reported for anthracene dissolved in binary 1-octanol + 2-propanol, 2-butanol + 1-butanol, 1-octanol + 1-butanol, 3-methyl-1-butanol + 1-propanol, and 2-methyl-1-propanol + 1-butanol mixtures at 25 C, and for pyrene dissolved in binary solvent mixtures containing 2-ethyl-1-hexanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-octanol, 2-methyl-1-propanol, and 3-methyl-1-butanol at 26 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the 12 systems studied, the combined NIBS/Redlich-Kister equation was found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being on the order of 0.4%. Slightly larger deviations were noted in the case of the modified Wilson equation.

  1. Solid–liquid equilibria for binary and ternary systems with the Cubic-Plus-Association (CPA) equation of state

    Fettouhi, André; Thomsen, Kaj

    2010-01-01

    A systematic investigation of the CPA model's performance within solid-liquid equilibria (SLE) in binary mixtures (methane + ethane, methane + heptane, methane + benzene, methane + CO2, ethane + heptane, ethane + CO2, 1-propanol + 1,4-dioxane, ethanol + water, 2-propanol + water) is presented. Th...

  2. Ruminal fermentation of anti-methanogenic nitro- and nitrate-containing forages in vitro

    Nitrate, 3-nitro-1-propionic acid (NPA), and 3-nitro-1-propanol (NPOH) can accumulate in forages and be poisonous to animals if fed at high enough amounts. These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied li...

  3. High-sensitivity titration microcalorimeter

    Velikov, A. A.; Grigoryev, S. V.; Chuikin, A. V.

    2015-02-01

    A differential titration microcalorimeter for studying intermolecular interactions in solutions has been designed. To increase the speed of the instrument, the dynamic correction method has been used. It has been shown that electrical calibration of the microcalorimeter is consistent with its chemical calibration. The use of the instrument for measuring the integral heats of dilution of 1-propanol has been demonstrated.

  4. Experimental validation of a rate-based model for CO2 capture using an AMP solution

    Gabrielsen, Jostein; Svendsen, H. F.; Michelsen, Michael Locht;

    2007-01-01

    Detailed experimental data, including temperature profiles over the absorber, for a carbon dioxide (CO"2) absorber with structured packing in an integrated laboratory pilot plant using an aqueous 2-amino-2-methyl-1-propanol (AMP) solution are presented. The experimental gas-liquid material balance...

  5. AGONISTIC SENSORY EFFECTS OF AIRBORNE CHEMICALS IN MIXTURES: ODOR, NASAL PUNGENCY, AND EYE IRRITATION

    Threshold responses of odor, nasal pungency (irritation), and eye irritation were measured for single chemicals (1-propanol, 1-hexanol, ethyl acetate, heptyl acetate, 2-pentanone, 2-heptanone, toluene, ethyl benzene, and propyl benzene) and mixtures of them (two three-component m...

  6. One pot direct synthesis of amides or oxazolines from carboxylic acids using Deoxo-Fluor reagent

    Kangani, Cyrous O.; Kelley, David E.

    2005-01-01

    A mild and highly efficient one pot–one step condensation and/or condensation–cyclization of various acids to amides and/or oxazolines using Deoxo-Fluor reagents is described. Parallel syntheses of various free fatty acids with 2-amino-2, 2-dimethyl-1-propanol resulted with excellent yields.

  7. Mass balance evaluation of alcohol emission from cattle feed

    Silage on dairy farms has been recognized as an important source of volatile organic compounds (VOCs) to the atmosphere, and therefore a contributor to tropospheric ozone. Considering reactivity and likely emission rates, ethanol, 1-propanol, and acetaldehyde probably make the largest contribution t...

  8. Correlation for fitting multicomponent vapor-liquid equilibria data and prediction of azeotropic behavior

    Khalid Farhod Chasib Al-Jiboury

    2007-01-01

    Full Text Available Correlation equations for expressing the boiling temperature as direct function of liquid composition have been tested successfully and applied for predicting azeotropic behavior of multicomponent mixtures and the kind of azeotrope (minimum, maximum and saddle type using modified correlation of Gibbs-Konovalov theorem. Also, the binary and ternary azeotropic point have been detected experimentally using graphical determination on the basis of experimental binary and ternary vapor-liquid equilibrium data.In this study, isobaric vapor-liquid equilibrium for two ternary systems: “1-Propanol – Hexane – Benzene” and its binaries “1-Propanol – Hexane, Hexane – Benzene and 1-Propanol – Benzene” and the other ternary system is “Toluene – Cyclohexane – iso-Octane (2,2,4-Trimethyl-Pentane” and its binaries “Toluene – Cyclohexane, Cyclohexane – iso-Octane and Toluene – iso-Octane” have been measured at 101.325 KPa. The measurements were made in recirculating equilibrium still with circulation of both the vapor and liquid phases. The ternary system “1-Propanol – Hexane – Benzene” which contains polar compound (1-Propanol and the two binary systems “1-Propanol – Hexane and 1-Propanol – Benzene” form a minimum azeotrope, the other ternary system and the other binary systems do not form azeotrope.All the data passed successfully the test for thermodynamic consistency using McDermott-Ellis test method (McDermott and Ellis, 1965.The maximum likelihood principle is developed for the determination of correlations parameters from binary and ternary vapor-liquid experimental data which provides a mathematical and computational guarantee of global optimality in parameters estimation for the case where all the measured variables are subject to errors and the non ideality of both vapor and liquid phases for the experimental data for the ternary and binary systems have been accounted.The agreement between prediction and experimental data is

  9. Characterization of volatile compounds of “Drenja”, an alcoholic beverage obtained from the fruits of cornelian cherry

    VELE TEŠEVIĆ

    2009-02-01

    Full Text Available In this study, volatile compounds were analyzed in five samples of home-made spirit beverage made by the distillation of fermented fruits of cornelian cherry (Cornus mas L.. The major volatile compounds, besides ethanol, identified and quantified were: methanol, acetaldehyde, 1-propanol, ethyl acetate, 2-methyl-1-propanol, 1-butanol, amyl alcohols, 1-hexanol and 2-phenylethanol. The minor volatiles were submitted to liquid–liquid extraction with dichloromethane and analyzed by gas chromatography and gas chromatography/ /mass spectrometry (GC/MS. A total of 84 compounds were identified. The most abundant compounds were straight-chain free fatty acids, ethyl esters of C6–C18 acids, limonene, 2-phenylethanol and 4-ethylphenol. Most of the compounds found in the “Drenja” spirits investigated in this study are similar to those present in other alcoholic beverages.

  10. Solubility of anthracene in binary alcohol + 2-pentanol and alcohol + 4-methyl-2-pentanol solvent mixtures

    Powell, J.R.; McHale, M.E.R.; Kauppila, A.S.M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1996-07-01

    Experimental solubilities are reported for anthracene dissolved in 16 binary mixtures containing either 2-pentanol or 4-methyl-2-pentanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 1-octanol, 2-methyl-1-propanol and 3-methyl-1-butanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the 16 systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being 0.3% and 0.5% for the combined NIBS/Redlich-Kister and modified Wilson equations, respectively.

  11. Solubility of anthracene in binary alcohol + 2-ethyl-1-hexanol solvent mixtures

    Powell, J.R.; McHale, M.E.R.; Kauppila, A.S.M.; Otero, P.; Jayasekera, M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1995-11-01

    Solid-liquid equilibrium data of organic nonelectrolyte systems are becoming increasingly important in the petroleum industry, particularly in light of present trends toward heavier feedstocks and known carcinogenicity/mutagenicity of many of the larger polycyclic aromatic compounds. Experimental solubilities are reported for anthracene dissolved in seven binary mixtures containing 2-ethyl-l-hexanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-octanol, 2-methyl-1-propanol, and 3-methyl-1-butanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the seven systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values on the order of 0.6%.

  12. Influência do dióxido de enxofre e cultivares de videira na formação de alguns compostos voláteis e na qualidade sensorial do destilado de vinho Influence of sulfur dioxide and grape varieties at the formation of some volatile compounds and at the sensory quality of the wine distillate

    Marco Antonio SALTON

    2000-12-01

    Full Text Available Com o objetivo de estudar o efeito do SO2 e das cultivares de videira - Herbemont, Couderc 13, Trebbiano e Isabel - na composição química e na qualidade sensorial do destilado de vinho, efetuaram-se microvinificações e posterior destilação dos vinhos na safra de 1996. As análises dos compostos voláteis foram feitas através de cromatografia gasosa e a avaliação sensorial dos destilados foi efetuada pelo grupo de degustação da Embrapa Uva e Vinho. Os resultados mostraram que o SO2 favoreceu a formação de etanal nas cultivares estudadas. Observou-se também um aumento na soma dos álcoois superiores em função do SO2, exceto para o destilado da cv. Isabel. Constatou-se que o destilado de Isabel se caracterizou por apresentar teor mais elevado de metanol e mais baixo de 1-propanol, possivelmente devido ao sistema de vinificação. O destilado de Isabel, juntamente com o de Couderc 13, apresentou teores mais baixos de 2-metil-1-propanol, 3-metil-1-butanol e da soma dos álcoois superiores. O destilado de Trebbiano apresentou teor mais elevado de 2-metil-1-propanol e juntamente com o de Herbemont teores mais elevados de 1-propanol, 2-metil-1-butanol, 3-metil-1-butanol e na soma dos álcoois superiores. A avaliação sensorial evidenciou que o SO2 influenciou na qualidade de aroma, no gosto agradável e na qualidade geral dos destilados das cultivares Herbemont e Trebbiano. O de Herbemont se caracterizou por apresentar menor qualidade de aroma, gosto agradável, tipicidade e qualidade geral. Apresentou, ainda, nota mais elevada para aroma e gosto indesejáveis.With the aim of studying the influence of SO2 and grape varieties - Herbemont, Couderc 13, Trebbiano and Isabella, on the chemical composition and sensory quality of wine distillates, some microvinification and posterior distillation of wines were made, at the harvest of 1996. The analyses of volatile components were made through gas chromatography and the sensory evaluation of

  13. Densities and viscosities of binary mixtures of {dimethylsulfoxide+aliphatic lower alkanols (C1-C3)} at temperatures from T=303.15K to T=323.15K

    Densities and viscosities for dimethylsulfoxide (DMSO) with methanol, ethanol, 1-propanol, and 2-propanol have been measured as a function of mole fraction at T=(303.15, 308.15, 313.15, 318.15, and 323.15)K and atmospheric pressure. From the measurements, excess molar volumes (VmE), excess viscosities (ηE), and Grunberg and Nissan interaction parameters (ε) have been calculated. The excess parameters are fitted to a Redlich-Kister equation. Excess molar volumes (VmE) are negative for (DMSO+methanol, +ethanol) systems throughout the whole range of composition. The (DMSO+1-propanol) system shows both positive and negative excess molar volumes and (DMSO+2-propanol) shows positive excess molar volume, hardly any negative value is observed in alcohol rich-region. The excess viscosities and interaction parameters of all the mixtures are negative except for the (DMSO+methanol) system which is positive

  14. Measurement and modeling of high-pressure (vapour + liquid) equilibria of (CO2 + alcohol) binary systems

    An apparatus based on a static-analytic method assembled in this work was utilized to perform high pressure (vapour + liquid) equilibria measurements with uncertainties estimated at 2 + 1-propanol), (CO2 + 2-methyl-1-propanol), (CO2 + 3-methyl-1-butanol), and (CO2 + 1-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 12) MPa. For all the (CO2 + alcohol) systems, it was visually monitored to insure that there was no liquid immiscibility at the temperatures and pressures studied. The experimental results were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapour + liquid) equilibria compositions were found to be in good agreement with the experimental values with deviations for the mol fractions <0.12 and <0.05 for the liquid and vapour phase, respectively.

  15. In Situ Enrichment of Phosphopeptides on MALDI Plates Functionalized by Reactive Landing of Zirconium(IV)–n-Propoxide Ions

    Blacken, Grady R.; Volný, Michael; Vaisar, Tomáš; Sadílek, Martin; Tureček, František

    2007-01-01

    We report substantial in situ enrichment of phosphopeptides in peptide mixtures using zirconium oxide coated plates for detection by MALDI-TOF mass spectrometry. The novel feature of this approach rests on the specific preparation of zirconium oxide coatings using reactive landing on stainless steel support of gas-phase positive ions produced by electrospray of zirconium(IV)–n-propoxide solutions in 1-propanol. Reactive landing was found to produce durable functionalized surfaces for selectiv...

  16. Sequential polymerization of ethylene oxide, ε-caprolactone and l-lactide: A one-pot metal-free route to tri- and pentablock terpolymers

    Zhao, Junpeng

    2014-01-01

    Metal-free polymerization of ethylene oxide (EO) catalyzed by a relatively mild phosphazene base (t-BuP2) was proven feasible, which enabled the one-pot sequential polymerization of EO, ε-caprolactone, and l-lactide. Using either 3-phenyl-1-propanol or water as an initiator, the corresponding triblock or pentablock terpolymers were easily prepared. © 2014 the Partner Organisations.

  17. Characterisation of volatile compounds in an alcoholic beverage produced by whey fermentation

    Dragone, Giuliano; Mussatto, Solange I.; Oliveira, J.M.; Teixeira, J.A.

    2009-01-01

    An alcoholic beverage (35.4% v/v ethanol) was produced by distillation of the fermented broth obtained by continuous whey fermentation with a lactose-fermenting yeast Kluyveromyces marxianus. Forty volatile compounds were identified in this drink by gas chromatography. Higher alcohols were the most abundant group of volatile compounds present, with isoamyl, isobutyl, 1-propanol, and isopentyl alcohols being found in highest quantities (887, 542, 266, and 176 mg/l, respectively). Ethyl acetate...

  18. The Extraction of Caffeine from Tea: An Old Undergraduate Experiment Revisited

    Murray, Scott D.; Hansen, Peter J.

    1995-09-01

    The extraction of caffeine from tea leaves is a common organic chemistry experiment. A water/1-propanol/sodium chloride ternary system was found to be a suitable replacement for the more traditional water/organochlorine solvent systems. Approximately 80% of the caffeine in the tea leaves can be recovered as crude caffeine. The ternary system employs chemicals which are not only less expensive, but also less toxic.

  19. Gas-Chromatographic Analysis of Major Volatile Compounds Found in Traditional Fruit Brandies from Transylvania, Romania

    Teodora Emilia RUSU COLDEA; Carmen SOCACIU; Maria PARV; Vodnar, Dan

    2011-01-01

    In the current study, the major volatile compounds from three categories of traditional fruit brandies (plum, apple and pear) were characterized by gas-chromatography (GC-FID). There were collected 26 samples from different locations of Transylvania (Romania), all made by traditional technologies involving fermentation in barrels and distillation in copper stills. The major volatile compounds, besides ethanol, identified and quantified were: acetaldehyde, ethyl acetate, methanol, 1-propanol, ...

  20. Gas-chromatographic analysis of some volatile congeners in different types of strong alcoholic fruit spirits

    Kostik, Vesna; Memeti, Shaban; Bauer, Biljana

    2013-01-01

    Beside ethyl alcohol, the major active component of alcoholic beverages, almost all alcoholic drinks contain volatile and non-volatile substances called congeners. They are present in different concentrations depending on beverage type and manufacturing methods. In the current study, the major volatile compounds besides ethanol as: methanol, ethyl acetate, 1-propanol (n-propanol), 2-propanol (i-propanol), 1-butanol(n-butanol), i-butanol (2-methylpropan-1-ol), n-amyl alcohol (n-pentanol), i-am...

  1. Metabolic Engineering of Microorganisms for the Production of Higher Alcohols

    Choi, Yong Jun; Lee, Joungmin; Jang, Yu-Sin; Lee, Sang Yup

    2014-01-01

    ABSTRACT Due to the increasing concerns about limited fossil resources and environmental problems, there has been much interest in developing biofuels from renewable biomass. Ethanol is currently used as a major biofuel, as it can be easily produced by existing fermentation technology, but it is not the best biofuel due to its low energy density, high vapor pressure, hygroscopy, and incompatibility with current infrastructure. Higher alcohols, including 1-propanol, 1-butanol, isobutanol, 2-me...

  2. Magnetic susceptibilities of bynary non-electrolyte mixtures

    Molar magnetic susceptibilities are determined by the Goy method for the following two systems: 1-propanol + methyl acetate and 2-propanol + methyl acetate at 298 K where the three molecules are polar and the alcohol molecules are associated in their pure state. Excess diamagnetic susceptibilties are calculated to obtain information about possible interactions. Diamagnetic suscetibilities were related with molecular polarizabilities by Boyer-Donzelot's equation and compared with experimental results. (author)

  3. Systematic study of the thermal diffusion in associated mixtures

    Polyakov, P.; Wiegand, S.

    2008-01-01

    We performed systematic temperature and concentration dependent measurements of the Soret coefficient in different associated binary mixtures of water, deuterated water, dimethyl sulfoxide (DMSO), methanol, ethanol, acetone, methanol, 1-propanol, 2-propanol, and propionaldehyde using the so-called thermal diffusion forced Rayleigh scattering method. For some of the associating binary mixtures such as ethanol/water, acetone/water, and DMSO/water, the concentration xw+/- at which the Soret coef...

  4. (Vapor + liquid) equilibria of the binary mixtures of m-cresol with C1-C4 aliphatic alcohols at 95.5 kPa

    Bubble point temperatures at 95.5 kPa, over the entire composition range, are measured for the binary mixtures formed by m-cresol with: methanol, ethanol, 1-propanol, 2-propanol, and n-, iso-, sec-, and tert-butanols - using a Swietoslawski-type ebulliometer. The liquid phase composition - bubble point temperature measurements are well represented by the Wilson model. (Vapor + liquid) equilibria predicted from the model are presented

  5. Characterization of Volatile Components in Makgeolli, a Traditional Korean Rice Wine, with or without Pasteurization, During Storage

    Sang Hoon Song; Young-Suk Kim; Sang Mi Lee; Hye-Jung Park

    2013-01-01

    Changes in the volatile components of unpasteurized and pasteurized makgeolli during 30 days of storage were investigated by gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry (GC-O). A total of 11 odor-active compounds such as 3-methyl-1-butanol (isoamyl alcohol), 2-methyl-1-butanol, 2,3-butanediol, butanoic acid, 3-methylbutanoic acid (isovaleric acid), 2-methylbutanoic acid, 3-(methylthio)-1-propanol (methionol), 2-phenylethanol, ethyl decanoate, ethyl dodecanoate, and ethyl ...

  6. Reaction Mechanism and Kinetics of Aqueous Solutions of Primary and Secondary Alkanolamines and Carbon Dioxide

    BAVBEK, Olgac; ALPER, Erdoğan

    1999-01-01

    The mechanism and kinetics of the reaction between aqueous solutions of CO2 and the alkanolamines 1-amino-2-propanol, 3-amino-1-propanol,2-methyl aminoethanol and 2-ethyl aminoethanol were investigated using a stopped flow technique. It was found that the reaction orders according to power law kinetics were between 1.1 and 2.0, depending on the alkanolamine and the concentration ranges investigated. This fractional order was therefore considered to be further evidence that carbamate ...

  7. Experimental study of thermodynamic and transport properties of binary mixtures of poly(ethylene glycol) diacrylate and alcohols at different temperatures

    Vuksanović Jelena M.; Radović Ivona R.; Šerbanović Slobodan P.; Kijevčanin Mirjana Lj.

    2015-01-01

    Experimental density r, refractive index nD and viscosity h data of three binary systems of poly(ethylene glycol) diacrylate (PEGDA) + ethanol, + 1-propanol, and + 1-butanol were measured at eight temperatures from (288.15 to 323.15) K, with temperature step of 5 K, and at atmospheric pressure. The experimental data were correlated as a function of PEGDA mole fraction and temperature. Densities and refractive indices of the investigated mixtures could be fi...

  8. Alcohol and water adsorption in zeolitic imidazolate frameworks

    Zhang, Ke

    2013-01-01

    Alcohol (methanol, ethanol, 1-propanol, 2-propanol and 1-butanol) and water vapor adsorption in zeolitic imidazolate frameworks (ZIF-8, ZIF-71 and ZIF-90) with similar crystal sizes was systematically studied. The feasibility of applying these ZIF materials to the recovery of bio-alcohols is evaluated by estimating the vapor-phase alcohol-water sorption selectivity. © 2013 The Royal Society of Chemistry.

  9. Enzymatic resolution of (R,S)-ibuprofen and (R,S)-ketoprofen by microbial lipases from native and commercial sources Resolução enzimática do (R,S)-ibuprofeno e (R,S)-cetoprofeno por lipases microbianas de fontes nativas e comerciais

    Patrícia de Oliveira Carvalho; Fabiano Jares Contesini; Masaharu Ikegaki

    2006-01-01

    The enantioselectivity (E) of native lipases from Aspergillus niger, Aspergillus terreus, Fusarium oxysporum, Mucor javanicus, Penicillium solitum and Rhizopus javanicus in the resolution of (R,S)-ibuprofen and (R,S)-ketoprofenenantiomers by esterification reaction with 1-propanol in isooctane was compared with known commercial Candida rugosa (Sigma) and Candida antarctica (Novozym®435) lipases. In the resolution of (R,S)-ibuprofen, C. rugosa lipase showed good selectivity (E = 12) while Novo...

  10. Synthesis of Non-Cytotoxic Poly(Ester-Amine) Dendrimers as Potential Solubility Enhancers for Drugs: Methotrexate as a Case Study

    Patricia Guadarrama; María Teresa Ramírez Apan; Jorge A. Cruz-Morales; Delia Soto-Castro

    2010-01-01

    This study describes the synthesis of two new families of dendrimers based on the esterification of N-alkylated 3-amine-1-propanol with two different cores, adipic acid (1st and 2nd generations) and ethylenediamine (generation 1.5), both with carboxylic acid end groups, offering a wide variety of further modifications at the periphery. According to the cytotoxic evaluation of the dendrimers and their possible degradation products within cell lines, these materials could be considered as innoc...

  11. Intermolecular Interactions in Ternary Glycerol–Sample–H2O

    Westh, Peter; Rasmussen, Erik Lumby; Koga, Yoshikata

    2011-01-01

    -butanol (TBA), 1-propanol (1P), urea (UR), NaF, NaCl, NaBr, NaI, and NaSCN were used. It was found that hydrophobes (TBA and 1P) reduce the values of HGly-GlyEHEGly--Gly considerably, but a hydrophile (UR) had very little effect on HGly-GlyEHEGly--Gly. The results with Na salts indicated that there have very...

  12. Indirectly suspended droplet microextraction of water-miscible organic solvents by salting-out effect for the determination of polycyclic aromatic hydrocarbons.

    Daneshfar, Ali; Khezeli, Tahere

    2014-12-01

    A simple and low-cost method that indirectly suspended droplet microextraction of water-miscible organic solvents (ISDME) by salting-out effect before high-performance liquid chromatography and ultraviolet (HPLC-UV) detection was used for the determination of polycyclic aromatic hydrocarbons (PAHs) in different samples. The ISDME is a combination of salting-out extraction of water-miscible organic solvent and directly suspended droplet microextraction (DSDME). Ninety-five microliters water-miscible organic solvent (1-propanol) was added to a 500-µL sample. A homogeneous solution was formed immediately. To produce a steady vortex at the top of the solution, the sample was agitated at 700 rpm using a magnetic stirrer. By the addition of ammonium sulfate (saturated solution) to the homogeneous solution, 1-propanol was separated and collected at the bottom of the steady vortex. Finally, 20 µL 1-propanol was injected into HPLC-UV. The effects of important parameters such as water-miscible organic solvent (type and volume), type of salt, and extraction time were evaluated. Under optimum conditions, the method has a good linear calibration range (0.1 µg/L-300 µg/L), coefficients of determination (R(2) > 0.998), low limits of detection (between 0.02 µg/L and 0.27 µg/L), and acceptable recovery (>85.0%). PMID:25242239

  13. Modelling of volumetric properties of binary and ternary mixtures by CEOS, CEOS/GE and empirical models

    BOJAN D. DJORDJEVIC

    2007-12-01

    Full Text Available Although many cubic equations of state coupled with van der Waals-one fluid mixing rules including temperature dependent interaction parameters are sufficient for representing phase equilibria and excess properties (excess molar enthalpy HE, excess molar volume VE, etc., difficulties appear in the correlation and prediction of thermodynamic properties of complex mixtures at various temperature and pressure ranges. Great progress has been made by a new approach based on CEOS/GE models. This paper reviews the last six-year of progress achieved in modelling of the volumetric properties for complex binary and ternary systems of non-electrolytes by the CEOS and CEOS/GE approaches. In addition, the vdW1 and TCBT models were used to estimate the excess molar volume VE of ternary systems methanol + chloroform + benzene and 1-propanol + chloroform + benzene, as well as the corresponding binaries methanol + chloroform, chloroform + benzene, 1-propanol + chloroform and 1-propanol + benzene at 288.15–313.15 K and atmospheric pressure. Also, prediction of VE for both ternaries by empirical models (Radojković, Kohler, Jackob–Fitzner, Colinet, Tsao–Smith, Toop, Scatchard, Rastogi was performed.

  14. Fiber content of diet affects exhaled breath volatiles in fasting and postprandial state in a pilot crossover study.

    Raninen, Kaisa J; Lappi, Jenni E; Mukkala, Maria L; Tuomainen, Tomi-Pekka; Mykkänen, Hannu M; Poutanen, Kaisa S; Raatikainen, Olavi J

    2016-06-01

    Our pilot study examined the potential of exhaled breath analysis in studying the metabolic effects of dietary fiber (DF). We hypothesized that a high-fiber diet (HFD) containing whole grain rye changes volatile organic compound (VOC) levels in exhaled breath and that consuming a single meal affects these levels. Seven healthy men followed a week-long low-fiber diet (17 g/d) and HFD (44 g/d) in a randomized crossover design. A test meal containing 50 g of the available carbohydrates from wheat bread was served as breakfast after each week. Alveolar exhaled breath samples were analyzed at fasting state and 30, 60, and 120 minutes after this meal parallel to plasma glucose, insulin, and serum lipids. We used solid-phase microextraction and gas chromatography-mass spectrometry for detecting changes in 15 VOCs. These VOCs were acetone, ethanol, 1-propanol, 2-propanol, 1-butanol, acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid, 2-methylbutyric acid, hexanoic acid, acetoin, diacetyl, and phenol. Exhaled breath 2-methylbutyric acid in the fasting state and 1-propanol at 120 minutes decreased (P = .091 for both) after an HFD. Ingestion of the test meal increased ethanol, 1-propanol, acetoin, propionic acid, and butyric acid levels while reducing acetone, 1-butanol, diacetyl, and phenol levels. Both DF diet content and having a single meal affected breathVOCs. Exploring exhaled breath further could help to develop tools for monitoring the metabolic effects of DF. PMID:27188907

  15. Selective deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo{sub 2}C) surfaces

    Xiong, Ke [Catalysis Center for Energy Innovation, Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716 (United States); Yu, Weiting [Chemical Engineering, Columbia University, New York, NY 10027 (United States); Chen, Jingguang G., E-mail: jgchen@columbia.edu [Chemical Engineering, Columbia University, New York, NY 10027 (United States)

    2014-12-30

    Highlights: • Mo{sub 2}C surface can deoxygenate propanal and 1-propanol to produce propene through a similar intermediate (propoxide or η{sup 2}(C,O)-propanal). • Mo{sub 2}C surface can deoxygenate furfural and furfuryl alcohol to make 2-methylfuran through a 2-methylfuran-like intermediate. • The presence of furan ring modifies the selectivity between deoxygenation and hydrogenation/dehydrogenation pathways. - Abstract: The selective deoxygenation of aldehydes and alcohols without cleaving the C-C bond is crucial for upgrading bio-oil and other biomass-derived molecules to useful fuels and chemicals. In this work, propanal, 1-propanol, furfural and furfuryl alcohol were selected as probe molecules to study the deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo{sub 2}C) prepared over a Mo(1 1 0) surface. The reaction pathways were investigated using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The deoxygenation of propanal and 1-propanol went through a similar intermediate (propoxide or η{sup 2}(C,O)-propanal) to produce propene. The deoxygenation of furfural and furfuryl alcohol produced a surface intermediate similar to adsorbed 2-methylfuran. The comparison of these results revealed the promising deoxygenation performance of Mo{sub 2}C, as well as the effect of the furan ring on the selective deoxygenation of the C=O and C-OH bonds.

  16. Trapped electrons in crystalline cyclodextrin matrices

    The formation of trapped electrons was found in crystalline matrices of several α-cyclodextrin inclusion complexes γ-irradiated at 77 K. ESR signals of the trapped electrons were structureless single-line spectra, for which width depended on the included molecules: 1.7, 0.5 and 1.5 mT for H2O, D2O and 1-propanol included in cyclodextrin molecule, respectively. Optical absorption spectra were essentially structureless broad bands with the absorption maxima at 530 and 410 nm for the H2O and 1-propanol complexes, and were bleached homogeneously with light of wavelength longer than the absorption maxima. No trapped electron was formed in the cyclodextrin-neopentane complex. The G values of photobleached entities, assigned mainly to the trapped electrons, were found to be 1.7 and 1.8 for the D2O and 1-propanol complexes, respectively. These results indicate that the electrons are trapped in the inner cavity of the α-cyclodextrin molecule about 0.5 nm diameter, together with the included molecules, and imply that the trapped electrons can be found even in crystalline matrices, if they have pre-existing traps available to localize the radiation-generated electrons. The trapped electrons in the present matrices, providing a model of electron trapping in better-known environments, were compared with those in amorphous matrices so far reported. (author)

  17. Selective deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) surfaces

    Highlights: • Mo2C surface can deoxygenate propanal and 1-propanol to produce propene through a similar intermediate (propoxide or η2(C,O)-propanal). • Mo2C surface can deoxygenate furfural and furfuryl alcohol to make 2-methylfuran through a 2-methylfuran-like intermediate. • The presence of furan ring modifies the selectivity between deoxygenation and hydrogenation/dehydrogenation pathways. - Abstract: The selective deoxygenation of aldehydes and alcohols without cleaving the C-C bond is crucial for upgrading bio-oil and other biomass-derived molecules to useful fuels and chemicals. In this work, propanal, 1-propanol, furfural and furfuryl alcohol were selected as probe molecules to study the deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) prepared over a Mo(1 1 0) surface. The reaction pathways were investigated using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The deoxygenation of propanal and 1-propanol went through a similar intermediate (propoxide or η2(C,O)-propanal) to produce propene. The deoxygenation of furfural and furfuryl alcohol produced a surface intermediate similar to adsorbed 2-methylfuran. The comparison of these results revealed the promising deoxygenation performance of Mo2C, as well as the effect of the furan ring on the selective deoxygenation of the C=O and C-OH bonds

  18. Densities and derived thermodynamic properties of binary (alkanol + boldine) mixtures in the compressed liquid region

    Highlights: ► We measured densities for {alkanol (ethanol or 1-propanol) + boldine} mixtures. ► Liquid densities are reported in the ranges of (1 to 20) MPa and (313 to 363) K. ► Thermodynamic derived properties were calculated using an empirical correlation. ► Extrapolated densities at atmospheric pressure agree with the literature data. - Abstract: In this work, densities of two binary systems of {alkanol (ethanol and 1-propanol) + boldine} are measured at temperatures from (313 to 363) K and pressures up to 20 MPa using an Anton Paar vibrating tube densimeter. Each (alkanol + boldine) system was prepared at five diluted compositions with respect to the alkaloid. These are (x2 = 0.0012, 0.0074, 0.0136, 0.0196, 0.0267) and (x2 = 0.0018, 0.0046, 0.0077, 0.0112, 0.0142) mixed in ethanol and 1-propanol, respectively. Experimental densities are correlated using an empirical 6-parameter equation with deviations within 0.04%. Extrapolated densities at atmospheric pressure agree with the literature data. Isobaric expansivity, isothermal compressibility, thermal pressure coefficient, and internal pressure have been calculated.

  19. A spectroscopic and theoretical study in the near-infrared region of low concentration aliphatic alcohols.

    Beć, Krzysztof B; Futami, Yoshisuke; Wójcik, Marek J; Ozaki, Yukihiro

    2016-05-11

    The near-infrared (NIR) spectra of low-concentration (5 × 10(-3) M) solutions in CCl4 of basic aliphatic alcohols, methanol, ethanol, and 1-propanol were, for the first time, calculated by second-order vibrational perturbation theory computations and were compared with the corresponding experimental data. Density functional theory (DFT) using single hybrid (B3LYP) and double hybrid (B2PLYP) density functionals and their derivatives with additional empirical dispersion correction (B3LYP-D3 and B2PLYP-D, respectively) and second order Møller-Plesset perturbation theory were used in combination with selected basis sets including fairly new basis sets from the "spectroscopic" SNS family, double-ζ SNSD and triple-ζ SNST basis sets. Each time, anharmonic vibrational modes and intensities were calculated by using second-order vibrational perturbation theory. The effect of solvent cavity on the calculated results was included by the application of a self-consistent reaction field with a polarized continuum model. Ethanol and 1-propanol have conformational isomerism; following a conformational analysis, theoretical spectra of all isomers were calculated and their final predicted NIR spectra were obtained as Boltzmann-averaged spectra of resolved conformers. For ethanol and 1-propanol, the observed broadening of the overtone band of the OH stretching mode was well reflected by the differences in the position of the relevant band among conformational isomers of these alcohols; the effect of solvent on broadening was also discussed. Detailed band assignments in the experimental NIR spectra of the studied alcohols were proposed based on the calculation of potential energy distributions. The final accuracy of the predicted NIR spectra for each of the theoretical methods was estimated based on the errors in calculated frequencies of overtones and combination bands. PMID:27137865

  20. Electron solvation in liquid alcohols. Effect of microscopic liquid structure

    Complete text of publication follows. Numerous theoretical works show that excess electrons in polar liquids can localize in cavities in which the surrounding solvent molecules create an attractive potential well. These cavities are called the pre-existing traps. Existence of the preformed traps in liquids is also suggested by results of the femtosecond time-resolved studies on the solvated electron. Thus, theoretical description of the pre-existing traps in various liquids is important for understanding the process of primary electron localization in these media. In the present work the structure of liquid alcohols, obtained by computer simulation, has been analyzed in order to identify the regions that can serve as pre-existing sites for primary localization of an excess electron. The calculations were performed for two alcohols: 1-propanol and 2-propanol, at 298 K. Configurations of molecules for each liquid sample were generated in a classical Molecular Dynamics Simulations. The static and dynamical properties of the traps have been investigated and described in terms of the statistical distributions of their geometrical parameters and their lifetimes, respectively. Moreover, we have connected these properties with the local structure of the medium around the traps. Our general conclusions are as follows: (1) electron traps in 1-propanol (generally in primary alcohols) are deeper in comparison with traps in 2-propanol (secondary alcohols), (2) electron solvation process in 1-propanol, in contrast to 2-propanol, does not involve breaking of hydrogen bonding net, (3) and they are consistent with the experimental results of Zhang et al. (Radiat. Phys. Chem., 1999, 54, 433) for electrons localized in those matrices

  1. Vapour pressures and osmotic coefficients of binary mixtures of 1-ethyl-3-methylimidazolium ethylsulfate and 1-ethyl-3-methylpyridinium ethylsulfate with alcohols at T = 323.15 K

    Osmotic coefficients of binary mixtures containing alcohols (ethanol, 1-propanol, and 2-propanol) and the ionic liquids 1-ethyl-3-methylimidazolium ethylsulfate and 1-ethyl-3-methylpyridinium ethylsulfate were determined at T = 323.15 K. Vapour pressure and activity coefficients of the studied systems were calculated from experimental data. The extended Pitzer model modified by Archer, and the modified NRTL model (MNRTL) were used to correlate the experimental data, obtaining standard deviations lower than 0.012 and 0.031, respectively. The mean molal activity coefficients and the excess Gibbs free energy of the studied binary mixtures were calculated from the parameters obtained with the extended Pitzer model of Archer.

  2. Potassium sorbate reduces production of ethanol and 2 esters in corn silage

    Hafner, Sasha; Franco, Roberta B; Kung, Limin;

    2014-01-01

    The objective of this work was to evaluate the effects of biological and chemical silage additives on the production of volatile organic compounds (VOC; methanol, ethanol, 1-propanol, methyl acetate, and ethyl acetate) within corn silage. Recent work has shown that silage VOC can contribute to poor...... air quality and reduce feed intake. Silage additives may reduce VOC production in silage by inhibiting the activity of bacteria or yeasts that produce them. We produced corn silage in 18.9-L bucket silos using the following treatments: (1) control (distilled water); (2) Lactobacillus buchneri 40788...

  3. Modeling of CO2 absorber using an AMP solution

    Gabrielsen, Jostein; Michelsen, Michael Locht; Stenby, Erling Halfdan;

    2006-01-01

    Abstract: An explicit model for carbon dioxide (CO2) solubility in an aqueous solution of 2-amino-2-methyl-1-propanol (AMP) has been proposed and an expression for the heat of absorption of CO2 has been developed as a function of loading and temperature. A rate-based steady-state model for CO2 ab...... absorption of CO2 into an AMP solution in a packed tower and validated against pilot-plant data from the literature. (c) 2006 American Institute of Chemical Engineers....

  4. Effects of potassium sorbate and Lactobacillus plantarum MTD1 on production of ethanol and other volatile organic compounds in corn silage

    Hafner, Sasha D.; Windle, Michelle; Merrill, Caitlyn;

    2015-01-01

    evaluate the effect of additives on production of nine silage VOC in corn silage, including compounds thought to contribute to poor air quality or affect feed intake (alcohols: methanol, ethanol, 1-propanol; esters: methyl acetate, ethyl acetate, ethyl lactate; and aldehydes: acetaldehyde, valeraldehyde...... results provide additional evidence that potassium sorbate is an effective additive for reducing production of ethanol and ethyl esters in corn silage. Combining potassium sorbate with L. plantarum may provide additional benefits, although the persistence of this effect for silages with higher VOC...

  5. DINAMIKA NASTAJANJA VIŠJIH ALKOHOLOV IN ESTROV V FERMENTIRANIH PIJAČAH IZ JEČMENOVEGA, KVINOJINEGA IN AJDOVEGA SLADU

    Brečko, Natalija

    2014-01-01

    Namen diplomskega dela je bila uvedba in validacija analizne metode za določanje višjih alkoholov in estrov v pivu in pivu podobnih pijačah v odvisnosti od surovine in zaporednega števila fermentacij. Omenjene spojine v pivu nastajajo kot stranski produkti med procesom fermentacije in prispevajo predvsem k aromi piva tako v pozitivnem kot v negativnem smislu. Pomembnejši alkoholi v pivu, ki smo jih določali so: metanol, 1-propanol, izobutanol (IUPAC nomenklatura: 2-metilpropan-1-ol), 2-met...

  6. Characteristic of Nitron for Use as a Chemical Sensor in Studies of the Upper Atmosphere

    Meadows, Kapres; Wright, Cassandra K.; Sims, S. C.; Morris, V. R.

    1997-01-01

    We are investigating the use of nitron as a potential chemical sensor for nitric acid and other electron deficient nitrogen oxides. Solutions of nitron in 1-propanol, toluene, and chloroform have been tested for use on a piezoelectric quartz crystal microbalance. We are testing various solvents and metal cations which can maximize the lifetime and reaction specificity of nitron so that they may be used as chemical coatings for stratospheric measurement of trace gases. Results of the work to date will be shown, and future direction discussed.

  7. Self-reduction of a copper complex MOD ink for inkjet printing conductive patterns on plastics.

    Farraj, Yousef; Grouchko, Michael; Magdassi, Shlomo

    2015-01-31

    Highly conductive copper patterns on low-cost flexible substrates are obtained by inkjet printing a metal complex based ink. Upon heating the ink, the soluble complex, which is composed of copper formate and 2-amino-2-methyl-1-propanol, decomposes under nitrogen at 140 °C and is converted to pure metallic copper. The decomposition process of the complex is investigated and a suggested mechanism is presented. The ink is stable in air for prolonged periods, with no sedimentation or oxidation problems, which are usually encountered in copper nanoparticle based inks. PMID:25482984

  8. A novel route to synthesis of glycerol dimethyl ether from epichlorohydrin with high selectivity

    The effective utilization of glycerol, a by-product in the production of biodiesel, into useful chemicals is desirable from the viewpoint of green chemistry. With this in mind, a novel and highly selective route to synthesizing glycerol dimethyl ether (2,3-dimethoxy-1-propanol), a potential fuel additive, from glycerol was proposed. This route uses both glycerol and methanol as starting materials, takes epichlorohydrin as an intermediate product, and utilizes HCl as a recycling agent. Hereinto, the key step of this route is the reaction between epichlorohydrin and methanol to produce 2,3-dimethoxy-1-propanol which is identified by GC–MS, ESI-MS, IR and NMR. The thermodynamics of this reaction was analyzed and the result showed that the thermodynamics of a reaction was favorable and a high product yield was expected. The effect of various parameters such as kind of acid catalyst, molar ratio of epichlorohydrin to methanol, reaction temperature and reaction time was studied. Among various acid catalysts investigated, the acidic ionic liquid [HSO3-b-N(CH3)3]HSO4 exhibited the highest activity and selectivity: conversion of epichlorohydrin of 100% and selectivity of 2,3-dimethoxy-1-propanol of 99% at 393 K, 10 h, an initial pressure of 0.1 MPa and a molar ratio of catalyst:ECH:CH3OH of 0.01:1:5. After the reaction, [HSO3-b-N(CH3)3]HSO4 was separated by vacuum distillation and then reused for the next cycle directly. The results showed that the product selectivity remained at about 94% but the conversion of epichlorohydrin dropped to 75% after being used five times. Subsequently, a reaction mechanism for the synthesis of 2,3-dimethoxy-1-propanol from epichlorohydrin and methanol was proposed. - Highlights: • Epichlorohydrin was converted effectively into glycerol dimethyl ether used as potential fuel additive. • The selectivity of 99% and the conversion of 100% under the mild reaction condition. • The reaction was high product selectivity and yield, mild

  9. Hydrogenotrophic Methanogenesis by Moderately Acid-Tolerant Methanogens of a Methane-Emitting Acidic Peat

    Horn, Marcus A.; Matthies, Carola; Küsel, Kirsten; Schramm, Andreas; Drake, Harold L.

    2003-01-01

    The emission of methane (1.3 mmol of CH4 m−2 day−1), precursors of methanogenesis, and the methanogenic microorganisms of acidic bog peat (pH 4.4) from a moderately reduced forest site were investigated by in situ measurements, microcosm incubations, and cultivation methods, respectively. Bog peat produced CH4 (0.4 to 1.7 μmol g [dry wt] of soil−1 day−1) under anoxic conditions. At in situ pH, supplemental H2-CO2, ethanol, and 1-propanol all increased CH4 production rates while formate, aceta...

  10. Synthesis of Non-Cytotoxic Poly(Ester-Amine Dendrimers as Potential Solubility Enhancers for Drugs: Methotrexate as a Case Study

    Patricia Guadarrama

    2010-11-01

    Full Text Available This study describes the synthesis of two new families of dendrimers based on the esterification of N-alkylated 3-amine-1-propanol with two different cores, adipic acid (1st and 2nd generations and ethylenediamine (generation 1.5, both with carboxylic acid end groups, offering a wide variety of further modifications at the periphery. According to the cytotoxic evaluation of the dendrimers and their possible degradation products within cell lines, these materials could be considered as innocuous. In preliminary studies, the synthesized dendrimers proved to be potential enhancers of solubility of highly hydrophobic drugs, like methotrexate, widely used in chemotherapy.

  11. New Chiral Metal Cluster Systems for Catalytic Asymmetric Syntheses of Chiral Alcohols

    LI Yan-yun; CHEN Jian-shan; YANG Chuan-bo; DONG Zhen-rong; LI Bao-zhu; ZHANG Hui; GAO Jing-xing; TAKAO Ikariya

    2004-01-01

    The efficient chiral Ru3(CO)12 systems were prepared in situ from Ru3(CO)12 and various chiral diiminoor diamino-diphosphine tetradentate ligands. The systems have been used for the asymmetric transfer hydrogenation of propiophenone in 2-propanol, leading to 1-phenyl-1-propanol in a 98% yield and 96% e.e. The IR study suggests that the carbonyl hydride anion [HRu3(CO)11]- most probably exists as a principal species under the reaction conditions. The high chiral efficiency may be due to the synergetic effect produced by the neighboring ruthenium atoms and a special chiral micro-environment involving the polydentate ligand and the Ru3 framework.

  12. Determination and correlation of the solubility of four Brønsted-acidic ionic liquids based on benzothiazolium cations in six alcohols

    Highlights: • Solubility of four acidic benzothiazolium cations-based ILs was measured. • The solubilities vary with the polarity of the solvent. • The solubility of some ILs is with “temperature-sensitive” property. • The measured solubilities were correlated by Apelblat model and λh model. • The dissolution enthalpy and entropy of ILs were calculated using the van’t Hoff equation. - Abstract: Solubilities of four acidic ionic liquids based on benzothiazolium cations in six alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-1-propanol) from at temperatures from (253 to 384) K were determined using a static equilibrium method under atmospheric pressure. The modified Apelblat equation and λh equation were employed to correlate the experimental data with good agreement. The solubilities of ILs increase with increasing temperature. It is interesting to find that the solubility of some ILs in alcohols are with “temperature-sensitive” properties. The solubility is related with the polarity and molecular structures of the solvent, as well as the strength of hydrogen bonding between alcohols and anionic groups of ILs. The dissolution enthalpy and entropy of ILs were calculated by the van’t Hoff equation. This study provides useful information for further research and application of the ionic liquids

  13. FTIR/PCA study of propanol in argon matrix: the initial stage of clustering and conformational transitions

    FTIR spectra of 1-propanol in an argon matrix were studied in the range 11 to 30 K. Principal component analysis of dynamic FTIR spectra and nonlinear band shape fitting has been carried out. The peaks of monomer, open dimer, mixed propanol-water dimer and those of higher H-bond clusters have been resolved and analyzed. The attribution of certain FTIR peaks has been supported by proper density functional theory calculations. Analyzing dependences of the integral band intensities of various aggregates on temperature it has been deduced that in the initial stage of clustering monomers and dimers are the basic building blocks forming higher H-bond clusters. The peaks assigned to two conformers of monomers and mixed propanol-water dimers were investigated processing the temperature dependences of their integral intensities in Arrhenius plot. The obtained values of 0.18 kJ.mol-1 for propanol monomer and 0.26 kJ.mol-1 for mixed dimer are well comparable with the energy differences between the global minimum conformation of 1-propanol (Gt) and some other energetically higher structures (Tt or Tg).

  14. Solvothermal synthesis and characterization of tungsten oxides with controllable morphology and crystal phase

    Graphical abstract: Display Omitted Research highlights: → Morphology and crystal phase of tungsten oxides depend on the solvothermal reaction solvents. The specific surface area and optical absorption depend on the morphology and crystal phase. Crystallinity has more important effects on photocatalytic activity than specific surface area. - Abstract: Tungsten oxides with various morphologies and crystal phases were synthesized by solvothermal reactions at 200 deg. C for 7-12 h using different solvents. The morphology and crystal phase of tungsten oxides changed depending on the solvents, i.e., spherical particles of ca. 1 μm in diameter consisting of nanowires, spindle shaped bundles of ca. 1 μm in length consisting of nanowires and accumulations consisting of micrometer sized plates and/or rods of tungsten oxides were obtained using ethanol, 1-propanol and water-ethanol mixed solution, respectively. When water-ethanol mixed solution was used, the crystallinity of tungsten oxide increased but the specific surface area greatly decreased. Crystallinity of tungsten oxides had more important effects on the NO degradation under light irradiation. The product using 42.9 vol.% water-ethanol mixed solvent consisted of the mixture of anhydrous tungsten oxide and hydrous tungsten oxide with preferential orientation of (0 0 2) plane and small band gap energy (2.43 eV), and showed higher photocatalytic degradation of NO even though it had a much smaller specific surface area than those prepared using ethanol and 1-propanol.

  15. Electron beam induced synthesis of uranium dioxide nanoparticles: Effect of solvent composition

    Rath, M. C.; Keny, S. J.; Naik, D. B.

    2016-09-01

    The effect of various compositions of solvents was investigated on the electron beam induced synthesis of uranium dioxide, UO2 nanoparticles. The synthesis was carried out at different pHs from 2 to 7 in the aqueous solutions containing 10 mM uranyl nitrate and 10% 2-propanol. The formation of UO2 nanoparticles was found to occur only in the pH range from 2.5 to 3.7. Experiments were also carried out in the aqueous solutions containing various other alcohols (10% v/v) such as methanol, ethanol, 1-propanol, 1-butanol or tert-butanol as well as in solutions containing 10 mM sodium formate at pH 3.4. The formation of UO2 nanoparticles in the aqueous solutions was found to occur only in the presence of ethanol, 1-propanol, 2-propanol or 1-butanol. It is therefore confirmed that the electron beam induced synthesis of UO2 nanoparticles strongly depends on the solvent compositions as well as the pH of the medium.

  16. Microemulsion System for Topical Delivery of Thai Mango Seed Kernel Extract: Development, Physicochemical Characterisation and Ex Vivo Skin Permeation Studies

    Jiraporn Leanpolchareanchai

    2014-10-01

    Full Text Available A microemulsion system containing Thai mango seed kernel extract (MSKE, cultivar “Fahlun” was developed and characterised for the purpose of topical skin delivery. The MSKE-loaded microemulsions were prepared by using the spontaneous emulsification method. Isopropyl myristate (IPM was selected as the oil phase. A polyoxyethylene sorbitan monooleate and sorbitan monododecanoate (1:1, w/w system was used as the surfactant phase; an aqueous mixture of different cosurfactants (absolute ethanol, 96.3% v/v ethanol, 1-propanol, 2-propanol or 1,2-propanediol at a weight ratio of 1:1 was used as the aqueous phase. Among the cosurfactants studied, the 1-propanol aqueous mixture had the largest microemulsion region (48.93% in the pseudo-ternary phase diagram. Microemulsions containing 1% MSKE demonstrated good physicochemical stability during a six-month study period at 25 ± 2 °C/60% ± 5% RH. The ex vivo skin permeation study demonstrated that the microemulsions exhibited a potent skin enhancement effect allowing MSKE to penetrate skin layers up to 60-fold higher compared with the control. Neither skin irritation nor skin corrosion was observed in ex vivo studies. The present study revealed that IPM-based microemulsion systems may be promising carriers to enhance skin penetration and delivering MSKE for topical treatment.

  17. Ideal Gas thermodynamic properties of simple alkanols

    The ideal gas thermodynamic properties (C /SUP o/ /SUB p/ , S /SUP o/ (T)-S0(O) and H /SUP o/ (T)-H /SUP o/ (0)) of methanol (CH3OH), ethanol (C2H5OH), 1-propanol (CH3CH2CH2OH), and 2-propanol ((CH3)2CHOH) over the temperature range 0 to 1500 K at 1.01325-bar (1-atm) pressure are calculated by the statistical mechanical method, employing the recent molecular and spectroscopic constants. The internal rotational contributions to the thermodynamic properties caused by the presence of -CH3,-C2H5, and -OH rotors in these molecules are evaluated using an internal rotational partition function formed by the summation of internal rotational energy levels for each rotor. In the calculation of the thermodynamic properties of ethanol (g) and 1-propanol (g), we adopted a molecular model that the vapor of each compound contains an equilibrium mixture of trans and gauche isomers. The existence of such isomers was observed spectroscopically in recent years. Our calculated results, such as C /SUP o/ /SUB p/ and S /SUP o/ (T)-S /SUP o/ (0), agree with available experimental values

  18. Thermodynamic properties of binary liquid mixtures of diethylenetriamine with alcohols at different temperatures

    Highlights: → Thermodynamic study of diethylenetriamine + 2-methyl-1-propanol, +2-propanol or +1-butanol have been made. → Excess molar volumes and isentropic compressibility were determined. → Types of interactions were discussed based on derived properties. - Abstract: Densities, ρ, viscosities, η, and speeds of sound, u, were measured for the binary liquid mixtures containing diethylenetriamine with 2-methyl-1-propanol, 2-propanol and 1-butanol at 293.15, 298.15, 303.15, 308.15 and 313.15 K. From density and speed of sound data, excess molar volumes, VmE and deviations in isentropic compressibility, Δκs, and speed of sound, Δu have been evaluated. Viscosity data were used to compute deviations in viscosity and excess Gibbs energy of activation of viscous flow ΔG*E at 298.15, 303.15 and 308.15 K. A Redlich-Kister type equation was applied to fit the excess molar volumes and deviations in isentropic compressibility, speed of sound and viscosity data. The viscosity data have been correlated with the equations of Grunberg-Nissan, Tamura-Kurata, Heric-Brewer and of Hind et al. All the binary systems of the present study have negative values of excess molar volumes and deviations in isentropic compressibility over whole composition range and at all temperatures which indicates strong interactions between the components of binary mixtures.

  19. Thermochemistry of the solution of β-alanine in (H2O + alcohol) mixtures at 298.15 K

    Highlights: • Enthalpies of β-alanine dissolution have been measured in aqueous solution of MeOH, EtOH, 1-PrOH and 2-PrOH. • Measured data were reported as functions of composition of water + alcohol mixtures. • Enthalpy coefficients of pairwise interactions have been analyzed in terms of McMillan–Mayer theory. - Abstract: The enthalpies of the solution of β-alanine in H2O + (methanol, ethanol, 1-propanol and 2-propanol) mixtures with alcohol content up to 0.4 mol fractions, have been determined calorimetrically at T = 298.15 K. The standard enthalpies of the solution and transfer of β-alanine from water to aqueous alcohol have been calculated. The effect of structure properties of a mixed solvent on specified enthalpy characteristics of β-alanine is discussed. The enthalpy coefficients of pairwise interactions between β-alanine and alcohol molecules have been computed. It has been found that these coefficients become increasingly positive in methanol, ethanol, 1-propanol, and 2-propanol sequence. A comparative analysis of thermodynamic characteristics of dissolution of β-alanine and D,L-α-alanine in the mixtures studied has been made

  20. Structure and thermodynamics of core-softened models for alcohols

    Munaò, Gianmarco, E-mail: gmunao@unime.it [Dipartimento di Fisica e di Scienze della Terra, Università degli Studi di Messina, Viale F. Stagno d’Alcontres 31, 98166 Messina (Italy); Urbic, Tomaz [Department of Chemistry and Chemical Technology, Chair of Physical Chemistry, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana (Slovenia)

    2015-06-07

    The phase behavior and the fluid structure of coarse-grain models for alcohols are studied by means of reference interaction site model (RISM) theory and Monte Carlo simulations. Specifically, we model ethanol and 1-propanol as linear rigid chains constituted by three (trimers) and four (tetramers) partially fused spheres, respectively. Thermodynamic properties of these models are examined in the RISM context, by employing closed formulæ for the calculation of free energy and pressure. Gas-liquid coexistence curves for trimers and tetramers are reported and compared with already existing data for a dimer model of methanol. Critical temperatures slightly increase with the number of CH{sub 2} groups in the chain, while critical pressures and densities decrease. Such a behavior qualitatively reproduces the trend observed in experiments on methanol, ethanol, and 1-propanol and suggests that our coarse-grain models, despite their simplicity, can reproduce the essential features of the phase behavior of such alcohols. The fluid structure of these models is investigated by computing radial distribution function g{sub ij}(r) and static structure factor S{sub ij}(k); the latter shows the presence of a low−k peak at intermediate-high packing fractions and low temperatures, suggesting the presence of aggregates for both trimers and tetramers.

  1. Influence of reaction conditions and type of alcohol on biodiesel yields and process economics of supercritical transesterification

    Highlights: • Transesterification in supercritical methanol, ethanol and 1-propanol investigated. • Effect of alcohol, reaction temperature, pressure and time on yields analyzed. • Temperature has the highest impact on yield, followed by time and pressure. • Direct material and energy costs for each of the production alternatives estimated. • Lowest costs are achieved at highest yields even at very low oil prices. - Abstract: Experiments with transesterification of rapeseed oil in supercritical alcohols (methanol, ethanol and 1-propanol) were carried out in a batch reactor at various reaction temperatures (250–350 °C), working pressure (8–12 MPa), reaction time, and constant 42:1 alcohol to oil molar ratio. Influence of different alcohols and reaction conditions on biodiesel yield was investigated using linear multiple regression models. Temperature had the highest impact on yields, followed by reaction time and pressure. With increased molecular weight of alcohols, relative importance of temperature for explanation of yields decreased and relative importance of time and pressure increased. Economic assessment has revealed that transesterification in supercritical methanol has the lowest direct material and energy costs. Yield has crucial impact on process economics. Direct costs decrease with increase in biodiesel yields. Even at very low prices of oil feedstock the lowest cost is achieved at the highest yield

  2. Microemulsion system for topical delivery of thai mango seed kernel extract: development, physicochemical characterisation and ex vivo skin permeation studies.

    Leanpolchareanchai, Jiraporn; Padois, Karine; Falson, Françoise; Bavovada, Rapepol; Pithayanukul, Pimolpan

    2014-01-01

    A microemulsion system containing Thai mango seed kernel extract (MSKE, cultivar "Fahlun") was developed and characterised for the purpose of topical skin delivery. The MSKE-loaded microemulsions were prepared by using the spontaneous emulsification method. Isopropyl myristate (IPM) was selected as the oil phase. A polyoxyethylene sorbitan monooleate and sorbitan monododecanoate (1:1, w/w) system was used as the surfactant phase; an aqueous mixture of different cosurfactants (absolute ethanol, 96.3% v/v ethanol, 1-propanol, 2-propanol or 1,2-propanediol) at a weight ratio of 1:1 was used as the aqueous phase. Among the cosurfactants studied, the 1-propanol aqueous mixture had the largest microemulsion region (48.93%) in the pseudo-ternary phase diagram. Microemulsions containing 1% MSKE demonstrated good physicochemical stability during a six-month study period at 25 ± 2 °C/60% ± 5% RH. The ex vivo skin permeation study demonstrated that the microemulsions exhibited a potent skin enhancement effect allowing MSKE to penetrate skin layers up to 60-fold higher compared with the control. Neither skin irritation nor skin corrosion was observed in ex vivo studies. The present study revealed that IPM-based microemulsion systems may be promising carriers to enhance skin penetration and delivering MSKE for topical treatment. PMID:25347456

  3. On-line concentration sample stacking coupled with water-in-oil microemulsion electrokinetic chromatography.

    Huang, Hsi-Ya; Liu, Wan-Ling; Singco, Brenda; Hsieh, Shih-Huan; Shih, Yung-Han

    2011-10-21

    This study describes for the first time, the ability of a normal stacking mode (NSM) on-line concentration step coupled with water-in-oil (W/O) microemulsion electrokinetic chromatography (MEEKC), using six common penicillin antibiotics (oxacillin, penicillin V, penicillin G, nafcillin, ampicillin, and amoxicillin) as test analytes. Optimization of penicillin separation in the conventional W/O MEEKC system demonstrated that change in the type and concentration of the oil phase (1-butanol) and column temperature had a pronounced effect on the separation. With the subsequent development of the NSM coupled with W/O MEEKC, improved separation and detection sensitivities were observed when an organic solvent plug (1-propanol; 1.04 cm) was placed between the W/O microemulsion and the sample solutions. This could be attributed to the solution viscosity difference between the aqueous sample zone and the organic solvent plug causing the penicillin to be stacked in this 1-propanol plug. The optimal NSM W/O MEEKC provided about 12-fold increase in detection sensitivity compared with conventional sample injection (50 mbar, 3 s). Finally, this proposed method was successfully applied in the analyses of several food samples (porcine organs) spiked with penicillin. PMID:21689819

  4. Influence of the composition of aqueous-alcohol solvents on the thermodynamic characteristics of L-phenylalanine dissolution at 298.15 K

    Badelin, Valentin G. [Laboratory of Thermodynamics of Solutions of Non-electrolytes and Biologically Active Substances, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045, Ivanovo (Russian Federation); Smirnov, Valeriy I., E-mail: vis@isc-ras.ru [Laboratory of Thermodynamics of Solutions of Non-electrolytes and Biologically Active Substances, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045, Ivanovo (Russian Federation)

    2011-11-10

    Highlights: Black-Right-Pointing-Pointer Enthalpies of L-phenylalanine dissolution have been measured in aqueous methanol, ethanol, 1-propanol and 2-propanol. Black-Right-Pointing-Pointer The measured data were reported as functions of composition of water + alcohol mixtures. Black-Right-Pointing-Pointer Enthalpy coefficients of pair-wise interactions have been analyzed in terms of McMillan-Mayer theory. Black-Right-Pointing-Pointer A comparative analysis of the characteristics of dissolution of L-phenylalanine and some other L-amino acids in the similar systems has been made. - Abstract: The enthalpies of L-phenylalanine dissolution in aqueous methanol, ethanol, 1-propanol and 2-propanol have been determined by calorimetry at 298.15 K and alcohol mole fractions up to x{sub 2} {approx}0.4. The standard enthalpies of solution {Delta}{sub sol}H Degree-Sign and transfer {Delta}{sub tr}H Degree-Sign from water to the mixed solvent as well as the enthalpy coefficients of L-phenylalanine-alcohol pair-wise interactions were calculated. The interrelation of the enthalpies of dissolution and transfer for L-phenylalanine with structural features of alcohols has been determined. A comparative analysis of the thermodynamic characteristics of dissolution of L-phenylalanine and some other amino acids (glycine, L-alanine, L-threonine and L-valine) in the mixtures studied has been made.

  5. Measurement and modeling of high-pressure (vapour + liquid) equilibria of (CO{sub 2} + alcohol) binary systems

    Gutierrez, Jorge E.; Bejarano, Arturo [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (Chile); Fuente, Juan C. de la, E-mail: juan.delafuente@usm.c [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (Chile); Centro Regional de Estudios en Alimentos Saludables, Blanco 1623, Valparaiso (Chile)

    2010-05-15

    An apparatus based on a static-analytic method assembled in this work was utilized to perform high pressure (vapour + liquid) equilibria measurements with uncertainties estimated at <5%. Complementary isothermal (vapour + liquid) equilibria results are reported for the (CO{sub 2} + 1-propanol), (CO{sub 2} + 2-methyl-1-propanol), (CO{sub 2} + 3-methyl-1-butanol), and (CO{sub 2} + 1-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 12) MPa. For all the (CO{sub 2} + alcohol) systems, it was visually monitored to insure that there was no liquid immiscibility at the temperatures and pressures studied. The experimental results were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapour + liquid) equilibria compositions were found to be in good agreement with the experimental values with deviations for the mol fractions <0.12 and <0.05 for the liquid and vapour phase, respectively.

  6. Gas-Chromatographic Analysis of Major Volatile Compounds Found in Traditional Fruit Brandies from Transylvania, Romania

    Teodora Emilia RUSU COLDEA

    2011-11-01

    Full Text Available In the current study, the major volatile compounds from three categories of traditional fruit brandies (plum, apple and pear were characterized by gas-chromatography (GC-FID. There were collected 26 samples from different locations of Transylvania (Romania, all made by traditional technologies involving fermentation in barrels and distillation in copper stills. The major volatile compounds, besides ethanol, identified and quantified were: acetaldehyde, ethyl acetate, methanol, 1-propanol, 2-butanol, iso-butylic alcohol, alcool amyl active, iso-amylic alcohol, 1-butanol and furfural. For each type of brandy, positive but no significant correlations between methanol and furfural concentrations in plum and apple brandy were noticed. To evaluate the differences in composition regarding the geographical origin of plum brandies and to analyze the composition of plum, apple and pear brandies it has been compared the mean values (MVP, MVA and MVPe obtained for each volatile. For plum brandies it has been observed differences among the mean values of each volatile, in samples originating from counties Cluj, Bistriţa-Năsăud and Maramureş. For methanol, acetaldehyde and 1-propanol the MVP Cluj values were significantly higher than MVP Bistriţa-Năsăud. For iso-butylic alcohol, amyl active alcohol, iso-amylic alcohol the MVP Cluj values were significantly higher than for Bistriţa-Năsăud and Maramureş, while for ethyl acetate and furfural the MVP Bistriţa-Năsăud were significantly higher than MVP Cluj and MVP Maramureş. When compared the mean values of volatiles in plum vs apple vs pear brandies, for ethyl acetate, methanol, 2-butanol, 1-propanol and 1-butanol, the MVPe values were significantly higher than MVA, for furfural, amyl active and iso-amylic alcohols, while for acetaldehyde the MVPe values were significantly higher than MVP. Methanol represented the major volatile component, characteristic to fruit brandies, released by enzymatic

  7. Odorous gaseous emissions as influence by process condition for the forced aeration composting of pig slaughterhouse sludge

    Highlights: • The gaseous emissions produced by various composting process conditions were characterized and quantified. • Nine compounds were potentially odorous: TMA, NH3, 2-pentanone, 1-propanol-2-methyl, acetophenone and sulphur forms. • The tested composting process conditions reduced odour emissions by a factor of 5–10. • A reduction of 105 to 106 is required to reach an odour threshold limit at peak event emissions. • Both aeration rate and bulking agent had the most impact on reducing odour emissions. - Abstract: Compost sustainability requires a better control of its gaseous emissions responsible for several impacts including odours. Indeed, composting odours have stopped the operation of many platforms and prevented the installation of others. Accordingly, present technologies collecting and treating gases emitted from composting are not satisfactory and alternative solutions must be found. Thus, the aim of this paper was to study the influence of composting process conditions on gaseous emissions. Pig slaughterhouse sludge mixed with wood chips was composted under forced aeration in 300 L laboratory reactors. The process conditions studied were: aeration rate of 1.68, 4.03, 6.22, 9.80 and 13.44 L/h/kg of wet sludge; incorporation ratio of 0.55, 0.83 and 1.1 (kg of wet wood chips/kg of wet sludge), and; bulking agent particles size of <10, 10 < 20 and 20 < 30 mm. Out-going gases were sampled every 2 days and their composition was analysed using gas chromatography coupled with mass spectrometry (GC–MS). Fifty-nine compounds were identified and quantified. Dividing the cumulated mass production over 30 days of composting, by odour threshold, 9 compounds were identified as main potential odour contributors: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone, 1-propanol-2-methyl, dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide and acetophenone. Five gaseous compounds were correlated with both aeration rate and bulking agent to

  8. Odorous gaseous emissions as influence by process condition for the forced aeration composting of pig slaughterhouse sludge

    Blazy, V., E-mail: vincent.blazy@irstea.fr [Irstea, UR GERE, 17 Avenue de Cucillé, CS 64427, F-35044 Rennes (France); Guardia, A. de, E-mail: amaury.de-guardia@irstea.fr [Irstea, UR GERE, 17 Avenue de Cucillé, CS 64427, F-35044 Rennes (France); Benoist, J.C; Daumoin, M. [Irstea, UR GERE, 17 Avenue de Cucillé, CS 64427, F-35044 Rennes (France); Lemasle, M.; Wolbert, D. [Laboratoire Sciences Chimiques de Rennes - équipe Chimie et Ingénierie des Procédés, UMR 6226 CNRS, ENSCR, Avenue du Général Leclerc, 35700 Rennes (France); Barrington, S., E-mail: suzellebarrington@sympatico.ca [Irstea, UR GERE, 17 Avenue de Cucillé, CS 64427, F-35044 Rennes (France); Concordia University, Department of Building, Civil and Environmental Engineering, 1455 de Maisonneuve, Montréal, QC H3G 1M8 (Canada)

    2014-07-15

    Highlights: • The gaseous emissions produced by various composting process conditions were characterized and quantified. • Nine compounds were potentially odorous: TMA, NH{sub 3}, 2-pentanone, 1-propanol-2-methyl, acetophenone and sulphur forms. • The tested composting process conditions reduced odour emissions by a factor of 5–10. • A reduction of 10{sup 5} to 10{sup 6} is required to reach an odour threshold limit at peak event emissions. • Both aeration rate and bulking agent had the most impact on reducing odour emissions. - Abstract: Compost sustainability requires a better control of its gaseous emissions responsible for several impacts including odours. Indeed, composting odours have stopped the operation of many platforms and prevented the installation of others. Accordingly, present technologies collecting and treating gases emitted from composting are not satisfactory and alternative solutions must be found. Thus, the aim of this paper was to study the influence of composting process conditions on gaseous emissions. Pig slaughterhouse sludge mixed with wood chips was composted under forced aeration in 300 L laboratory reactors. The process conditions studied were: aeration rate of 1.68, 4.03, 6.22, 9.80 and 13.44 L/h/kg of wet sludge; incorporation ratio of 0.55, 0.83 and 1.1 (kg of wet wood chips/kg of wet sludge), and; bulking agent particles size of <10, 10 < 20 and 20 < 30 mm. Out-going gases were sampled every 2 days and their composition was analysed using gas chromatography coupled with mass spectrometry (GC–MS). Fifty-nine compounds were identified and quantified. Dividing the cumulated mass production over 30 days of composting, by odour threshold, 9 compounds were identified as main potential odour contributors: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone, 1-propanol-2-methyl, dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide and acetophenone. Five gaseous compounds were correlated with both aeration rate and

  9. Method for producing high surface area chromia materials for catalysis

    Gash, Alexander E.; Satcher, Joe; Tillotson, Thomas; Hrubesh, Lawrence; Simpson, Randall

    2007-05-01

    Nanostructured chromium(III)-oxide-based materials using sol-gel processing and a synthetic route for producing such materials are disclosed herein. Monolithic aerogels and xerogels having surface areas between 150 m.sup.2/g and 520 m.sup.2/g have been produced. The synthetic method employs the use of stable and inexpensive hydrated-chromium(III) inorganic salts and common solvents such as water, ethanol, methanol, 1-propanol, t-butanol, 2-ethoxy ethanol, and ethylene glycol, DMSO, and dimethyl formamide. The synthesis involves the dissolution of the metal salt in a solvent followed by an addition of a proton scavenger, such as an epoxide, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively.

  10. Fast online emission monitoring of volatile organic compounds (VOC) in wastewater and product streams (using stripping with direct steam injection).

    Schocker, Alexander; Lissner, Bert

    2012-03-01

    Open-loop stripping analysis (also referred to as dynamic headspace) is a very flexible and robust technology for online monitoring of volatile organic compounds in wastewater or coolant. However, the quality and reliability of the analytical results depend strongly on the temperature during the stripping process. Hence, the careful and constant heating of the liquid phase inside the stripping column is a critical parameter. In addition, this stripping at high temperatures extends the spectrum of traceable organics to less volatile and more polar compounds with detection limits down to the ppm-level. This paper presents a novel and promising approach for fast, efficient, and constant heating by the direct injection of process steam into the strip medium. The performance of the system is demonstrated for temperatures up to 75 °C and traces of various hydrocarbons in water (e.g., tetrahydrofuran, methanol, 1-propanol, n-butanol, ethylbenzene). PMID:22186871

  11. Osmotic coefficients of binary mixtures of 1-butyl-3-methylimidazolium methylsulfate and 1,3-dimethylimidazolium methylsulfate with alcohols at T = 323.15 K

    Measurements of osmotic coefficients of BMimMSO4 (1-butyl-3-methylimidazolium methylsulfate) and MMimMSO4 (1,3-dimethylimidazolium methylsulfate) with ethanol, 1-propanol, and 2-propanol at T = 323.15 K are reported in this work. Vapour pressure and activity values for the binary systems studied are obtained from experimental results. The osmotic coefficients are correlated using the extended Pitzer model modified by Archer and the modified NRTL (MNRTL) model. The standard deviations obtained with both models are lower than 0.013 and 0.060, respectively. The parameters obtained with the extended Pitzer model of Archer are used to calculate the mean molal activity coefficients and the excess Gibbs free energy of the binary mixtures

  12. Vapour pressures, osmotic and activity coefficients for binary mixtures containing (1-ethylpyridinium ethylsulfate + several alcohols) at T = 323.15 K

    Osmotic coefficients of binary mixtures containing several primary and secondary alcohols (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) and the pyridinium-based ionic liquid 1-ethylpyridinium ethylsulfate were determined at T = 323.15 K using the vapour pressure osmometry technique. From the experimental results, vapour pressure and activity coefficients can be determined. For the correlation of osmotic coefficients, the extended Pitzer model modified by Archer, and the modified NRTL (MNRTL) model were used, obtaining deviations lower than 0.017 and 0.047, respectively. The mean molal activity coefficients and the excess Gibbs free energy for the binary mixtures studied were determined from the parameters obtained with the extended Pitzer model modified by Archer.

  13. Derived thermodynamic properties of alcohol + cyclohexylamine mixtures

    IVONA R. RADOVIĆ

    2010-02-01

    Full Text Available Thermal expansion coefficients, α, excess thermal expansion coefficients, αE, isothermal coefficients of pressure excess molar enthalpy, (∂HE/∂pT,x, partial molar volumes, , partial molar volumes at infinite dilution, , partial excess molar volumes, , and partial excess molar volumes at infinite dilution, , were calculated using experimental densities and excess molar volumes, , data. All calculations are performed for the binary systems of cyclohexylamine with 1-propanol or 1-butanol or 2-butanol or 2-methyl-2-propanol. The Redlich–Kister polynomial and the reduced excess molar volume approach were used in the evaluation of these properties. In addition, the aim of this investigation was to provide a set of various volumetric data in order to asses the influence of temperature, chain length and position of hydroxyl group in the alcohol molecule on the molecular interactions in the examined binary mixtures.

  14. Transient infrared temperature measurements of liquid-fuel surfaces: results of studies of flames spread over liquids.

    Konishi, T; Ito, A; Saito, K

    2000-08-20

    An infrared thermograph technique with an 8-12-microm spectral range was used to measure transient two-dimensional profiles of liquid (1-propanol) surface temperatures. An IR camera was placed over the liquid, allowing us to observe the fuel surface through propanol vapor. To use this technique, one must know the emissivity of the liquid surface and the IR absorption of both the liquid propanol and the propanol vapor. The emissivity of the liquid propanol was determined with a fine thermocouple temperature measurement, IR absorption with the propanol vapor was calibrated with a blackbody source, and IR absorption with a liquid propanol was theoretically estimated. The accuracy of our infrared thermograph technique proved to be better than 97% in detecting the liquid-surface temperature with a temperature sensitivity of 0.1 degrees C and a time response of 30 ms. PMID:18350009

  15. Significance of volatile compounds produced by spoilage bacteria in vacuum-packed cold-smoked salmon ( Salmo salar ) analyzed by GC-MS and multivariate regression

    Jørgensen, Lasse Vigel; Huss, Hans Henrik; Dalgaard, Paw

    2001-01-01

    Changes were studied in the concentration of 38 volatile compounds during chilled storage at 5 degreesC of six lots of commercially produced vacuum-packed cold-smoked salmon and sterile cold-smoked salmon. The majority of volatile compounds produced during spoilage of cold-smoked salmon were......-carboxaldehyde produced by autolytic activity. Only a few of the volatile compounds produced during spoilage of cold-smoked salmon had an aroma value high enough to indicate contribution to the spoilage off- flavor of cold-smoked salmon. These were trimethylamine, 3- methylbutanal, 2-methyl-1-butanol, 3-methyl-1-butanol......, 1- penten-3-ol, and 1-propanol. The potency and importance of these compounds was confirmed by gas chromatography- olfactometry. The present study provides valuable information on the bacterial reactions responsible for spoilage off-flavors of cold-smoked salmon, which can be used to develop...

  16. Densities, excess molar volumes, speeds of sound and isothermal compressibilities for {l_brace}2-(2-hexyloxyethoxy)ethanol + n-alkanol{r_brace} systems at temperatures between (288.15 and 308.15) K

    Pal, Amalendu [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)], E-mail: palchem@sify.com; Gaba, Rekha [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)

    2008-05-15

    The densities, {rho} and the speeds of sound, u, for {l_brace}2-(2-hexyloxyethoxy)ethanol (C{sub 6}E{sub 2}) + methanol, +1-propanol, +1-pentanol, and +1-heptanol{r_brace} have been measured as a function of composition using an Anton-Paar DSA 5000 densimeter at temperatures (288.15, 293.15, 298.15, 303.15, and 308.15) K and atmospheric pressure over the whole concentration range. The {rho} and u values were used to calculate excess molar volumes, V{sup E}, and excess molar isentropic compressibility, K{sub S,m}{sup E}, respectively. Also, thermal expansivity, {alpha}, partial molar volume, V-bar{sub i}, and partial molar volume of the components at infinite dilution, V-bar{sub i}{sup 0}, have been calculated. The variation of these properties with composition and temperature of the mixtures are discussed in terms of molecular interactions.

  17. Rapid preparation and characterization of methacrylate-based monoliths for chromatographic and electrophoretic separation.

    Fan, Li-Qun; Zhang, Yu-Ping; Gong, Wen-Jun; Qu, Ling-Bo; Lee, Kwang-Pill

    2010-01-01

    Butyl-methacrylate-based porous monoliths were rapidly prepared in the fused-silica capillary with a 10-cm stripe of polyimide removed from its exterior. The photopolymerization could be carried out in 150 s using ethylene glycol dimethacrylate as a cross-linking agent; 1-propanol, 1,4-butanediol, and water as tri-porogenic solvents; and Irgacure 1800 as a photo-initiator. The effect of different morphologies on the efficiency and retention properties was investigated using pressure-assisted CEC (p-CEC), CEC, and low pressure-assisted liquid chromatography modes (LPLC). Baseline separation of the model analytes was respectively achieved including thiourea, toluene, naphthalene, and biphenyl with the lowest theoretical height up to 8.0 microm for thiourea in the mode of p-CEC. Furthermore, the influence of the tri-porogenic solvents on the morphology of methacrylate-based monoliths was systematically studied with mercury intrusion porosimetry and scanning electron microscopy. PMID:20515536

  18. Synthesis of functionalized poly(ester carbonate) with laminin-derived peptide for promoting neurite outgrowth of PC12 cells.

    Xing, Dongming; Ma, Lie; Gao, Changyou

    2014-10-01

    Maleimide-functionalized poly(ester carbonate)s are synthesized by ring-opening copolymerization of furan-maleimide functionalized trimethylene carbonate (FMTMC) with L-lactide and a subsequent retro Diels-Alder reaction. The maleimide groups on poly(ester carbonate)s are amenable to Michael addition with thiol-containing molecules such as 3-mercapto-1-propanol, 2-aminoethanethiol hydrochloride, and mercaptoacetic acid under mild conditions, enabling the formation of biodegradable materials with various functional groups (e.g., hydroxyl, amine, and carboxyl). In particular, the maleimide-functionalized poly(ester carbonate) is clicked with a laminin-derived peptide CQAASIKVAV. In vitro culture of PC12 cells shows that the maleimide-functionalized polymers, especially the CQAASIKVAV-grafted one, could support cell proliferation and neurite outgrowth. The maleimide-functionalized poly(ester carbonate)s provide a versatile platform for diverse functionalization and have comprehensive potential in biomedical engineering. PMID:24962245

  19. Characterization of Volatile Components in Makgeolli, a Traditional Korean Rice Wine, with or without Pasteurization, During Storage

    Sang Hoon Song

    2013-05-01

    Full Text Available Changes in the volatile components of unpasteurized and pasteurized makgeolli during 30 days of storage were investigated by gas chromatography-mass spectrometry (GC-MS and GC-olfactometry (GC-O. A total of 11 odor-active compounds such as 3-methyl-1-butanol (isoamyl alcohol, 2-methyl-1-butanol, 2,3-butanediol, butanoic acid, 3-methylbutanoic acid (isovaleric acid, 2-methylbutanoic acid, 3-(methylthio-1-propanol (methionol, 2-phenylethanol, ethyl decanoate, ethyl dodecanoate, and ethyl tetradecanoate were determined in both the pasteurized and unpasteurized makgeolli during 30 days of storage. Although there were no significant differences in the concentrations of odor-active compounds at the initial storage time, most of odor-active compounds were more significantly increased in unpasteurized makgeolli compared to the pasteurized one during the storage period.

  20. A re-appraisal of the concept of ideal mixtures through a computer simulation study of the methanol-ethanol mixtures

    Požar, Martina; Lovrinčević, Bernarda; Zoranić, Larisa; Mijaković, Marijana; Sokolić, Franjo; Perera, Aurélien

    2016-08-01

    Methanol-ethanol mixtures under ambient conditions of temperature and pressure are studied by computer simulations, with the aim to sort out how the ideality of this type of mixtures differs from that of a textbook example of an ideal mixture. This study reveals two types of ideality, one which is related to simple disorder, such as in benzene-cyclohexane mixtures, and another found in complex disorder mixtures of associated liquids. It underlines the importance of distinguishing between concentration fluctuations, which are shared by both types of systems, and the structural heterogeneity, which characterises the second class of disorder. Methanol-1propanol mixtures are equally studied and show a quasi-ideality with many respect comparable to that of the methanol-ethanol mixtures, hinting at the existence of a super-ideality in neat mono-ol binary mixtures, driven essentially by the strong hydrogen bonding and underlying hydroxyl group clustering.

  1. Quantum-chemical modeling of energy parameters and vibrational spectra of chain and cyclic clusters of monohydric alcohols

    The specific peculiarities of alcohols such as heightened viscosity, boiling temperature and surface tension can be explained by the capability of their molecules to form relatively stable associates named clusters due to hydrogen bonding. In present work the stability of different chain-like and cyclic clusters of methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol and 1-hexanol was investigated by means of quantum-chemical simulation and particular by recently developed DFT exchange–correlation functional M06-2X. The relative stability of the cluster structure was evaluated by the total energy per molecule at low temperatures (where all alcohols exist in solid state) and by the changing of the free Gibbs energy upon cluster formation at the room temperature. For the verification of revealed results the conformity of calculated IR spectra of the most stable cluster structures with the experimental IR spectra at different temperatures was analyzed.

  2. Influence of cyclodextrin on the UCST- and LCST-behavior of poly(2-methacrylamido-caprolactam-co-(N,N-dimethylacrylamide

    Alexander Burkhart

    2014-08-01

    Full Text Available The monomer 2-methacrylamido-caprolactam (4 was synthesized from methacryloyl chloride (3 and racemic α-amino-ε-caprolactam (2. Copolymerization of 4 with N,N-dimethylacrylamide (5 was carried out by a free-radical mechanism using 2,2’-azobis(2-methylpropionitrile (AIBN as an initiator. The new copolymers show a lower critical solution temperature (LCST in water and an upper critical solution temperature (UCST in ethanol, 1-propanol, and 1-butanol. The solubility properties of the copolymers can be influenced significantly by the addition of randomly methylated β-cyclodextrin (CD. The complexation of the copolymers with CD, was confirmed by the use of ROESY-NMR-spectroscopy.

  3. Application of Surfactant Micellar Solutions as Extractants and Mobile Phases for TLC-Determination of Purine Bases and Doping Agents in Biological Liquids

    Daria Victorovna Yedamenko

    2015-04-01

    Full Text Available Separation of caffeine and its metabolites (theophylline and theobromine and doping agents (spironolactone, propranolol, and ephedrine and determination of caffeine in serum sample and propranolol and ephedrine in urine were studied on normal-phase thin layers (“Sorbfil-UV-254”. Aqueous organic solvents and aqueous micellar surfactant solutions were compared as the mobile phases for separation. The acceptable separation of purine bases and doping agents was achieved by micellar Thin Layer Chromatography and normal-phase Thin Layer Chromatography. Anionic surfactant solution with added 1-propanol was the best eluent as for caffeine, theophylline, and theobromine separation, as for doping agents. The best characteristics of caffeine extraction from serum, and propranolol and ephedrine from urine were achieved when micellar eluent based on non-ionic Tween-80 surfactant was used. DOI: http://dx.doi.org/10.17807/orbital.v7i1.632

  4. Measurement and Correlation for Solubility of Diosgenin in Some Mixed Solvents

    陈飞雄; 赵明蕊; 冯露; 任保增

    2014-01-01

    The solubility data of diosgenin in mixed systems of ethanol+1-propanol (1︰1), ethanol+1-butanol (1︰1), ethanol+isobutyl alcohol (1︰1), methanol+isobutyl alcohol (1︰1), methanol+isobutyl alcohol (1︰4), ethanol+1-pentanol (1︰1) and carbon tetrachloride were measured over the temperature range from 289.15 K to 334.15 K by a laser monitoring observation technique at atmospheric pressure, with all mixtures mixed by volume ratio. The Apelblat equation, the ideal solution model, and theλh equation are used to correlate the solubility data. The results show that the three models agree well with the experimental data, providing essential support for industrial design and further theoretical study.

  5. The Simulation of High Pressure Nucleation Experiments in Diffusion Cloud Chamber

    Fisenko, Sergey P

    2007-01-01

    For high- pressure nucleation experiments in upward diffusion cloud chamber, there is the great deviation of predictions of classical nucleation theory from experimental results; the discrepancy is more than 10 orders of magnitude of nucleation rate. Experimental data for 1-propanol vapor are under investigation in this paper. It was shown that mathematical model of a single droplet growth and motion semi- quantitatively explained all experimentally discovered regularities. For explanations low nucleation rate versus high supersaturation, the coalescence mechanism in gaseous phase has been proposed. As result of coalescence the vast majority of newly formed clusters evaporate and restore vapor density and temperature profile in DCC. The observed picture with low nucleation rate is result of diffusion interaction between small clusters and droplets in nucleation zone for high- pressure nucleation experiments.

  6. Measurements and modeling of VLLE at elevated pressures

    Laursen, Torben

    has traditionally been considered very time consuming. This work aims at developing and operating an equipment which allows routine measurements of both VLE and VLLE, in the temperature range of 25-45°C and pressure range of 1-100 bar. This has been done by taking advantage of on-line sampling and......The analysis of multiphase systems at elevated pressure is of great interest both from an academic side and an industrial point of view. The literature contains limited data for such systems, and the measurement of the composition of the different phases of multiphase systems at elevated pressures...... pure component calibration. Samples from the different liquid phases in the high-pressure cell is taken using a moveable needle. The systems investigated have been a combination of the components: CO2, N2, di-methyl ether (DME), water, methanol, ethanol and 1-propanol. 41 isotherms have been measured...

  7. Liquid-feed flame spray pyrolysis synthesis of oxide nanopowders for the processing of ceramic composites

    Taylor, Nathan John

    In the liquid-feed flame spray pyrolysis (LF-FSP) process, alcohol solutions of metalloorganic precursors are aerosolized by O2 and combusted. The metal oxide combustion products are rapidly quenched (researchers to further refine microstructural size. LF-FSP flame temperatures were mapped using different alcohols with different heats of combustion: methanol, ethanol, 1-propanol, and n-butanol. The effect of different alcohols on particle size and phase was determined through studies on Al2O3, Y2O3 and TiO2 nanopowders. The final studies describe the morphology of composite nanopowders produced in the WO3-TiO2 and CuO-TiO2 systems. The composite nanopowders have novel morphology, and may offer novel electronic, optical, or catalytic properties.

  8. Solubility and phase behavior of binary systems containing salts based on transitional metals

    Highlights: • Solubilities of salts were enhanced by temperature increase. • For all studied systems activity coefficients lower then unity were observed. • Melting point depression of 20 K was observed for [bmim]3[GdCl6]. -- Abstract: Tri(1-ethyl-3-methylimidazolium) gadolinium hexachloride ([emim]3[GdCl6]), tri(1-butyl-3-methylimidazolium) hexagadolinium chloride ([bmim]3[GdCl6]), di(tetramethylammonium) manganese tetrachloride ([TMA]2[MnCl4]) and cholinium tetrachloroferrate ([Chol][FeCl4]) were synthetized and their solubility in water, ethanol, 1-propanol and 1-butanol were determined as a function of temperature. Activity coefficients were calculated and their comparison with ideal solutions is discussed. The experimental data were correlated successfully by means of the semi-empirical Grant equation. In addition, melting point depression effect of high pressure carbon dioxide was studied

  9. Solubility of anthracene in binary alcohol + 3-methoxy-1-butanol solvent mixtures

    McHale, M.E.R.; Horton, A.S.M.; Padilla, S.A.; Trufant, A.L.; Sancha, N.U. De La; Vela, E.; Powell, J.R.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1997-01-01

    Experimental solubilities are reported for anthracene dissolved in ten binary mixtures containing 3-methoxy-1-butanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-methyl-1-butanol, 4-methyl-2-pentanol, 1-octanol, and 2-ethyl-1-hexanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the ten systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being 0.4% and 0.5% for the combined NIBS/Redlich-Kister and modified Wilson equations, respectively.

  10. Solubility of anthracene in binary alcohol + 2-propoxyethanol solvent mixtures

    McHale, M.E.R.; Powell, J.R.; Kauppila, A.S.M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

    1996-03-01

    Solid-liquid equilibrium data of organic nonelectrolyte systems are becoming increasingly important in the petroleum industry, particularly in light of present trends toward heavier feedstocks and known carcinogenicity/mutagenicity of many of the larger polycyclic aromatic compounds. Experimental solubilities are reported for anthracene dissolved in seven binary mixtures containing 2-propoxyethanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 1-octanol, and 3-methyl-1-butanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the seven systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values being on the order of 0.5%.

  11. Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4-triazine-5-one: Synthesis, characterization, catalytic and antibacterial studies

    AYALOOR SUBRAMANIAN RAMASUBRAMANIAN

    2011-01-01

    Full Text Available Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4-triazine-5-one with metal precursors, such as Cu(II, Ni(II, Co(II and Pd(II, were synthesized and characterized by physico–chemical and spectroscopic techniques. All the complexes are of the ML type. Based on analytical, spectral data and magnetic moments, the Co(II and Ni(II complexes were assigned octahedral geometries, while the Cu (II and Pd(II complexes square planar. A study on the catalytic oxidation of benzyl alcohol, cyclohexanol, cinnamyl alcohol, 2-propanol and 2-methyl-1-propanol was performed with N-methylmorpholine-N-oxide (NMO as co-oxidant. All the complexes and their parent organic moiety were screened for their biological activity on several pathogenic bacteria and were found to possess appreciable bactericidal properties.

  12. Prebiotic Oxidative Polymerization of 2,3 Dimercaptopropanol on the Surface of Iron(III) Hydroxide Oxide

    Weber, Arthur L.

    1994-01-01

    The oxidation of 2,3-Dimercapto-1-propanol by ferric ions on the surface of iron (III) hydroxide oxide yielded polydisulfide polymers. This polymerization occured readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron (III) hydroxide oxide (20 mg, 160 micro mole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the mineral phase. Reactions at higher dithiol concentrations with the same ratio of dithiol to mineral gave a higher yield of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis will be discussed.

  13. Complex formation equilibria of some beta-amino-alcohols with lead(II) and cadmium(II) in aqueous solution.

    Canepari, S; Carunchio, V; Castellano, P; Messina, A

    1998-12-01

    A study of complex formation equilibria of some beta-amino-alcohols with lead(II) and cadmium(II) ions at 25 degrees C and in 0.5 M KNO(3) is reported. The amino-alcohols considered are 2-amino-1-propanol, 2-amino-1-butanol, 2-amino-1-pentanol and 2-amino-1,3-propanediol. sec-Buthylamine and 2-amino-1-methoxy-propane have been also considered for comparison. The results are discussed in terms of ligand structure, paying attention to the number of hydroxyl groups and to the length of the alkyl residual. A weak contribution of the alcoholic oxygen in the coordination of cadmium(II) and the presence of a mixed hydroxyl species in lead(II) containing systems are hypothesized. PMID:18967412

  14. Solvent effects on stress corrosion cracking of zirconium and Zircaloy-4 in iodine

    Localized corrosion (pitting, intergranular attack and stress corrosion cracking) of Zircaloy-4 and its principal component, zirconium, was investigated in solutions of iodine in different alcohols (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol and 1-octanol). Intergranular attack was found in all of the solutions tested, and the attack velocity increases when the size of the alcohol molecule decreases. In some cases it was found that intergranular attack is accompanied by pitting. Slow strain-rate experiments showed that the propagation rate of stress corrosion cracks also depends on the size of the solvent molecule. From these results it may be inferred that the cause of the variation in the velocity is the steric hindrance of the alcohol molecules. The surface mobility SCC mechanism may account for these results. (author)

  15. Enhancement of radiopharmaceutical excretion by chemical interventions

    The goal was to find methods of decreasing the radiation dose after radionuclide studies, by giving a compound that will increase the rate of excretion of the radionuclide. Sprague - 1 Dawley rats were given Tc-99m pertechnetate, Ga-67 citrate or Tl-201 chloride intravenously followed at intervals of 1 to 24 hours by one of the following compounds: desferroxamine (DFO), 2,3-dimercapto-1-propanol (BAL), triethylene tetraamine hexaacetic acid (TETHA), stannous tartarate, bleomycin (BLEO), 2,3-dimercaptosuccinic acid (DMSA), diethylene-triaminepentaacetic acid (DTPA), DTPA+SnCl.2H2O, dihydroxybenzoic acid (DHB), and ferric-cyanoferrate (IT)(Prussian blue, PB). All the agents except PB are chelators. Some of these agents enhance excretion through the urinary tract (DFO), while most are excreted through the bile. PB was shown to increase Cs excrection through the G.I. tract

  16. Composição físico-química do vinho Bordô de Flores da Cunha, RS, elaborado com uvas maturadas em condições de baixa precipitação Physicochemical composition of Bordô wines from Flores da Cunha, RS, made with grapes matured in low rain conditions

    Francine Maria Tecchio

    2007-10-01

    Full Text Available O Bordô é, depois do Isabel, o vinho de mesa de maior importância econômica na Serra Gaúcha, pois existe um considerável segmento de mercado que o aprecia, especialmente por seu sabor frutado e por sua cor intensa e matiz violeta. Devido a isso e às condições de estiagem que ocorreram no verão de 2005, quando as chuvas corresponderam a 38% da normal climatológica, analisaram-se vinhos Bordô do município de Flores da Cunha, RS, um dos mais importantes produtores da Serra Gaúcha. Os vinhos analisados eram varietalmente puros e elaborados segundo a tecnologia de cada vinícola. Avaliaram-se 39 variáveis, das quais os resultados mais expressivos foram os seguintes: álcool 10,58% v/v; acidez total 91meq L-1; acidez volátil 7,3meq L-1; pH 3,21; extrato seco 24,24g L-1; açúcares redutores 2,90g L-1; extrato seco reduzido 22,34g L-1; cinzas 2,09g L-1; ácido tartárico 5,35g L-1; DO 420 0,480; DO 520 1,296; DO 620 0,184; taninos 1,41g L-1; antocianinas 778,8mg L-1; etanal 14,9mg L-1; acetato de etila 59,3mg L-1; metanol 290,9mg L-1; 1-propanol 24,9mg L-1; 2-metiL-1-propanol 40,6mg L-1; 2-metiL-1-butanol 45,9mg L-1; 3-metiL-1-butanol 149,1mg L-1; soma dos álcoois superiores 260,5mg L-1; e K 953mg L-1.The Bordô, after Isabel, is the table wine presenting the greater economic importance in the Serra Gaúcha region, because there is a segment of the market that likes its characteristics, specially its fruity flavor, color intensity, and violet hue. Due to these aspects and to the very dry climatic conditions in the 2005 summer, where rain represented 38% of the climatological normal, Bordô wines were analyzed from the commune of Flores da Cunha, RS, Brazil, one of the most important producers of the Serra Gaúcha region. Analyzed wines were varietal ones and made according to the technology of each winery. Thirty nine variables were evaluated and the average parameters of the most expressive ones were the following: alcohol 10.58% v

  17. Capture of carbon dioxide by amine-impregnated as-synthesized MCM-41

    Jianwen Wei; Lei Liao; Yu Xiao; Pei Zhang; Yao Shi

    2010-01-01

    The novel carbon dioxide (CO2) adsorbents with a high capture efficiency were prepared through impregnating the as-synthesized MCM-41 with three kinds of amines,namely diethylenetdamine (DETA),tdethylenetetramine (TETA) and 2-amino-2-methyl-1-propanol (AMP).The resultant samples were characterized by small angle X-ray diffraction and low temperature N2 adsorption.The synthesis way not only saves the energy or extractor to remove the template but also is environmentally friendly due to the absence of the potential pollutants such as toluene.CO2 capture was investigated in a dynamic packed column.The sample impregnated by TETA showed the highest adsorption capacity,approximately 2.22 mmol/g at 60℃ due to its highest amino-groups content among the three amines,The CO2 adsorption behavior was also investigated with the deactivation model,which showed an excellent prediction for the breakthrough curves.

  18. Kinetics study of CO2 absorption in AMP and Piperazine solutions

    Usman, Muhammad

    2012-01-01

    Kinetics of CO2 in AMP (2-amino 2-methyl 1-propanol) with concentration of 0.1/0.5/1.0/2.0/3.0/4.0 M, 3M AMP with CO2 loadings of 0.15/0.22/0.29 and 0.1/0.5/1.0/1.5M piperazine solutions were measured at a temperature range of 25-70oC. The AMP system was measured at 1KPa pressure of CO2 while CO2- loaded AMP and piperazine were measured at different partial pressures that range from 1-9KPa. The experiments for AMP system were performed in string of disc contactor while PZ system was measured ...

  19. Henry’s constants and activity coefficients of some organic solutes in 1-butyl,3-methylimidazolium hydrogen sulfate and in 1-methyl,3-trimethylsilylmethylimidazolium chloride

    Highlights: ► New solubility data are reported for two ionic liquids. ► Density data are reported. ► Thermo-gravimetric analysis data are obtained. - Abstract: Using a customized capillary gas–liquid chromatography column, Henry’s constants and activity coefficients at infinite dilution are reported for benzene, toluene, ethyl acetate, 1,4-dioxane, 1,2-dimethoxyethane, acetonitrile, nitromethane, tetrahydrofuran, chloroform, methanol, ethanol, and 1-propanol in ionic liquids 1-butyl,3-methylimidazolium hydrogen sulfate [BMIM][HSO4] and 1-methyl,3-trimethylsilylmethylimidazolium [SiMIM][Cl] chloride from 313 to 413 K. These acidic ionic liquids may provide suitable media for acid-catalyzed chemical reactions.

  20. Catalytic activity of carbon nanotubes in the conversion of aliphatic alcohols

    Zhitnev, Yu. N.; Tveritinova, E. A.; Chernyak, S. A.; Savilov, S. V.; Lunin, V. V.

    2016-06-01

    Carbon nanotubes (CNTs) obtained via the catalytic pyrolysis of hexane at 750°C were studied as the catalysts in conversion of C2-C4 alcohols. The efficiency of CNTs as catalysts in dehydration and dehydrogenation of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and tert-butanol was studied by means of pulse microcatalysis. The surface and structural characteristics of CNTs are investigated via SEM, TEM, DTA, BET, and XPS. CNTs are shown to be effective catalysts in the conversion of alcohols and do not require additional oxidative treatment. The regularities of the conversion of aliphatic alcohols, related to the properties of the CNTs surface and the structure of the alcohols are identified.

  1. Effect of water content on the stress corrosion cracking susceptibility of Zircaloy-4 in iodine-alcoholic solutions

    The stress corrosion cracking (SCC) susceptibility of Zircaloy-4 (UNS R60804) was studied in 10 g/L iodine dissolved in various alcohols: methanol, ethanol, 1 propanol, 1-butanol, 1-pentanol and 1-octanol. SCC was observed in all the systems studied and it was found that the higher the size of alcohol molecule, the lower the SCC susceptibility. The existence of intergranular attack -controlled by the diffusion of the active species- is a condition for the SCC process to occur. In the present work the inhibiting effect of water on the SCC susceptibility of Zircaloy-4 in iodine-alcoholic solutions was also investigated and the results showed that the minimum water content to inhibit the SCC process depends on the type of alcohol used as a solvent. (author)

  2. Enhancement of radiopharmaceutical excretion by chemical interventions

    Oster, Z.H.; Som, P.; Brill, A.B.; Sacker, D.F.; Atkins, H.L.

    1982-01-01

    The goal was to find methods of decreasing the radiation dose after radionuclide studies, by giving a compound that will increase the rate of excretion of the radionuclide. Sprague - 1 Dawley rats were given Tc-99m pertechnetate, Ga-67 citrate or Tl-201 chloride intravenously followed at intervals of 1 to 24 hours by one of the following compounds: desferroxamine (DFO), 2,3-dimercapto-1-propanol (BAL), triethylene tetraamine hexaacetic acid (TETHA), stannous tartarate, bleomycin (BLEO), 2,3-dimercaptosuccinic acid (DMSA), diethylene-triaminepentaacetic acid (DTPA), DTPA+SnCl.2H/sub 2/O, dihydroxybenzoic acid (DHB), and ferric-cyanoferrate (IT)(Prussian blue, PB). All the agents except PB are chelators. Some of these agents enhance excretion through the urinary tract (DFO), while most are excreted through the bile. PB was shown to increase Cs excrection through the G.I. tract. (ACR)

  3. Excess Molar Volume and Apparent Molar Volume of Binary Mixtures of 2—Methyl—3—buten—2—ol with 1—Alcohol at 298.15K

    LIUDixia; LIHaoran; 等

    2002-01-01

    Excess molar volumes (VmE) of binary mixtures of 2-methyl-3-buten-2-ol[CH3C(OH)(CH3)CHCH2] with four 1-alcohols:methanol,ethanol,1-propanol and 1-butanol at 298.15K and atmospheric pressure are derived from density measurements with a vibrating-tube densimeter.All the excess volumes are negative in the systems over the entire composition range. The results are correlated with the Redlich-Kister equation.The effects of chain length of 1-alcohols on VmE are discussed.The apparent molar volumes of 2-methyl-3-buten-2-ol and 1-alcohols are calculated respectively.

  4. Chemical isomeric effects on propanol glassy structures

    Cuello, G J; Bermejo, F J; Cabrillo, C

    2002-01-01

    We have studied the structure of both propanol isomers in their glassy and crystalline states by neutron diffraction. The glass-transition temperatures of 1- and 2-propanol are about 98 and 115 K, respectively and, surprisingly, even larger differences are observed for the melting temperatures of the stable crystals, which are 148 and 185 K, respectively. Their supercooled liquid phases show rather different relaxation spectra, 1-propanol manifesting strong deviations from Debye behavior, whereas 2-propanol shows a far weaker effect. We discuss the spectra obtained for the static structure factor and the static pair correlation function D(r). There is a noticeable difference in the position of the first sharp diffraction peak, which clearly indicates a density change, well correlated with the period of the intermolecular oscillations shown by D(r). (orig.)

  5. Use of a flor velum yeast for modulating colour, ethanol and major aroma compound contents in red wine.

    Moreno, Juan; Moreno-García, Jaime; López-Muñoz, Beatriz; Mauricio, Juan Carlos; García-Martínez, Teresa

    2016-12-15

    The most important and negative effect of the global warming for winemakers in warm and sunny regions is the observed lag between industrial and phenolic grape ripeness, so only it is possible to obtain an acceptable colour when the ethanol content of wine is high. By contrast, the actual market trends are to low ethanol content wines. Flor yeast growing a short time under velum conditions, decreases the ethanol and volatile acidity contents, has a favorable effect on the colour and astringency and significantly changes the wine content in 1-propanol, isobutanol, acetaldehyde, 1,1-diethoxiethane and ethyl lactate. The Principal Component Analysis of six enological parameters or five aroma compounds allows to classify the wines subjected to different velum formation conditions. The obtained results in two tasting sessions suggest that the flor yeast helps to modulate the ethanol, astringency and colour and supports a new biotechnological perspective for red winemakers. PMID:27451159

  6. A study on corrosion resistant graphene films on low alloy steel

    Sai Pavan, A. S.; Ramanan, Sutapa Roy

    2016-04-01

    Graphene nanosheets were produced after synthesizing graphene oxide via Hummer's method and a modified Hummer's method. The obtained graphene after reduction was dispersed in 1-propanol to get a coating solution. Mild steel coupons were coated with the graphene solution via dip coating method. Corrosion studies were carried out at different environments like water (pH 6.0), HCl (0.1 N), NaCl (3.5 wt%) and NaOH (1 M). Tafel analysis showed a reduction in the corrosion rate up to 99 % after three layer deposition with the graphene developed using the modified Hummer's method. X-ray diffraction and Raman Spectroscopy confirmed the presence of graphene.

  7. Application of the ERAS model to volumetric properties of binary mixtures of banana oil with primary and secondary alcohols (C1-C4) at different temperatures

    The densities of binary mixtures of {isoamyl acetate + alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol)}, including those of pure liquids, over the entire composition range were measured at temperatures (293.15 to 333.15) K and atmospheric pressure by means of a vibrating-tube densimeter. The excess molar volume, VmE, thermal expansion coefficients, α, and their excess values, αE, were calculated from density data. The VmE values are positive over the entire range of composition and temperature and become more positive with increasing temperature for all of the mixtures except for the (isoamyl acetate + methanol) mixture. The VmE values were correlated by Redlich-Kister equation and the extended real associated solution (ERAS) model was used for describing VmE values at T = 303.15 K.

  8. Transition from van-der-Waals to H Bonds dominated Interaction in n-Propanol physisorbed on Graphite

    Wolff, Matthias; Huber, Patrick; Knorr, Klaus; Volkmann, Ulrich G; 10.1103/PhysRevLett.106.156103

    2011-01-01

    Multilayer sorption isotherms of 1-propanol on graphite have been measured by means of high-resolution ellipsometry within the liquid regime of the adsorbed film for temperatures ranging from 180 to 260 K. In the first three monolayers the molecules are oriented parallel to the substrate and the growth is roughly consistent with the Frenkel-Halsey-Hill-model (FHH) that is obeyed in van-der-Waals systems on strong substrates. The condensation of the fourth and higher layers is delayed with respect to the FHH-model. The fourth layer is actually a bilayer. Furthermore there is indication of a wetting transition. The results are interpreted in terms of hydrogen-bridge bonding within and between the layers.

  9. Thermodynamic behavior of binary mixtures CnMpyNTf2 ionic liquids with primary and secondary alcohols

    Highlights: ► Osmotic coefficients of alcohols with CnMpyNTf2 (n = 2, 3, 4) are determined. ► Experimental data were correlated with Extended Pitzer model of Archer and MNRTL. ► Mean molal activity coefficients and excess Gibbs free energies were calculated. ► The results have been interpreted in terms of interactions. - Abstract: In this paper, the osmotic and activity coefficients and vapor pressures of the binary mixtures containing the ionic liquids 1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, C2MpyNTf2, and 1-methyl-3-propylpyridinium bis(trifluoromethylsulfonyl)imide, C3MpyNTf2, with 1-propanol, or 2-propanol and the ionic liquid 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, C4MpyNTf2, with 1-propanol or 2-propanol or 1-butanol or 2-butanol were determined at T = 323.15 K using the vapor pressure osmometry technique. The influence of the structure of the alcohol and of the ionic liquid on both coefficients and vapor pressures is discussed and a comparison with literature data on binary mixtures containing ionic liquids with different cations and anion is also performed. Besides, the results have been interpreted in terms of solute–solvent and ion–ion interactions. The experimental osmotic coefficients were correlated using the Extended Pitzer model of Archer and the Modified Non-Random Two Liquids model obtaining standard deviations lower than 0.059 and 0.102 respectively, and the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated.

  10. Effects of solvent hydrogen bonding, viscosity, and polarity on the dispersion and alignment of nanofluids containing Fe2O3 nanoparticles

    Christensen, Greg; Younes, Hammad; Hong, Haiping; Smith, Pauline

    2015-12-01

    It has been shown that the alignment of Iron (III) oxide (Fe2O3) nanoparticles in water (H2O) can enhance the thermal conductivity of nanofluids. To better understand solvent effects such as hydrogen bonding, viscosity, and polarity, nanofluids were prepared by mixing Fe2O3 nanoparticles and various solvents (water, ethanol, 1-propanol, isopropanol, 2-propanone, hexane, cyclohexane, ethylene glycol, glycerol, etc.), and the dispersions and alignments of the Fe2O3 nanoparticles in these solvents with and without an applied magnetic field were investigated using an optical microscope. The microscope images indicated that inter-molecule hydrogen bonding of the solvents with one OH group (water, ethanol, 1-propanol, and isopropanol) could help to disperse and align the Fe2O3 nanoparticles. The intra-molecular hydrogen bonding causes a dramatic increase in viscosity for fluids with multiple OH groups, such as ethylene glycol (C2H6O2) and glycerol (C3H8O3), and makes the Fe2O3 nanoparticles dispersion and alignment difficult. Adding water to those fluids could lead to significantly reduced viscosity and make the particles disperse and align well. Polarity studies indicated that higher polarity yields better dispersion and alignment of the Fe2O3 nanoparticles. Thermal studies showed that thermal conductivity of nanofluids containing metal oxide particles with hydrogen bonding in solvents is enhanced compared to the theoretically calculated data. Intermolecular hydrogen bonding between water and ethylene glycol increases the thermal conductivity of nanofluids while decreasing the fluid viscosity. The results also well explain why 50 wt. % water/50 wt. % ethylene glycol is an excellent commercial coolant. Since high thermal conductivity enhancement with minimal viscosity increase is the primary goal of heat transfer nanofluids, this current research may open new doors to better understanding of the fundamental nature of nanofluids.

  11. Conversion of 1,3-Propylene Glycol on Rutile TiO2(110)

    Chen, Long; Li, Zhenjun; Smith, R. Scott; Kay, Bruce D.; Dohnalek, Zdenek

    2014-10-09

    The adsorption of 1,3-propylene glycol (1,3-PG) on partially reduced TiO2(110) and its conversion to products have been studied by a combination of molecular beam dosing and temperature programmed desorption (TPD). When the Ti surface sites are saturated by 1,3-PG, ~80% of the molecules undergo further reactions to yield products that are liberated during the TPD ramp. In contrast to ethylene glycol (EG) and 1,2- propylene glycol (1,2-PG) that yield only alkenes and water at very low coverages (< 0.05 ML), two additional products, HCHO and C2H4, along with propylene (CH3CHCH2) and water are observed for 1,3-PG. Identical TPD line shapes and desorption yields for HCHO and C2H4 suggest that these products result from C-C bond cleavage and are coupled. At higher 1,3-PG coverages (> 0.1 ML), propanal (CH3CH2CHO) and two additional products, 1-propanol (CH3CH2CH2OH) and acrolein (CH2CHCHO), are observed. The desorption of 1-propanol is found to be coupled with the desorption of acrolein, suggesting that these products are formed by the disproportionation of two 1,3-PG molecules. The coverage dependent TPD results further show that propylene formation dominates at low coverages (< 0.3 ML), while the decomposition and disproportionation channels increase rapidly at higher coverages and reach yields comparable to that of propylene at the 1,3-PG saturation coverage of 0.5 ML. The observed surface chemistry clearly shows how the molecular structure of glycols influences their reaction pathways on oxide surfaces.

  12. Avaliação de mosto de uva fermentado Evaluation of fermented grape must

    Maria Eugênia de Oliveira Mamede

    2007-06-01

    Full Text Available O objetivo deste estudo foi determinar a concentração de compostos voláteis nos mostos de uva Chardonnay e Pinot Noir fermentados pela Pichia membranaefaciens, como também analisar as fases de crescimento da levedura durante a fermentação a 15 e 20 °C. Compostos voláteis majoritários da fermentação como: etanol, acetato de etila, acetato de isoamila, acetaldeido, 1-propanol, isobutanol e álcool isoamílico foram isolados e quantificados pelo sistema de "Purge and Trap". A fermentação conduzida a 15 °C mostrou ser mais adequada na produção de acetato de etila, com valores inferiores a 200 mg.L-1 (131,3 e 147,0 mg.L-1 nos mostos Pinot Noir e Chardonnay, respectivamente, enquanto que a 20 °C a produção foi de 286,0 e 270,0 mg.L-1 nos mostos Pinot Noir e Chardonnay, respectivamente.The aim of this study was to determine the concentration of volatile compounds in Chardonnay and Pinot Noir grape musts. The study also aims to analyze yeast growth phases during fermentation at 15 and 20 °C. Major volatile compounds of fermentation such as ethanol, ethyl acetate, isoamyl acetate, acetaldehyde, 1-propanol, 3-methyl butanol and 2-methyl butanol were isolated and quantified using the Purge and Trap system. Fermentation carried out at 15 °C was more appropriate in the production of ethyl acetate (131.3 and 147.0 mg.L-1 in the Pinot Noir and Chardonnay musts, respectively, whilst at 20 °C the production was of 286.0 and 270.0 mg.L-1 in the Pinot Noir and Chardonnay musts respectively.

  13. Studies of solvent effects on reaction dynamics using ultrafast transient absorption spectroscopy

    Harris, Don Ahmasi

    Ultrafast transient absorption spectroscopy was used to investigate the solvent dependent reaction dynamics of two prototypical chemical systems: (1) The ring-opening reaction of 1,3-cyclohexadiene, the isolated chromophore in Provitamin D, and (2) The photolysis of various Vitamin B12 cofactors. We investigated the influence of solvent polarity on the ground state conformational relaxation of 1,3,5-cis hexatriene subsequent to the ring opening of 1,3-cyclohexadiene in methanol and 1-propanol solvents. Comparisons to the conformational relaxation in alkane solvents studied earlier demonstrated a surprising influence of solvent polarity on single bond isomerization. Temperature dependent transient absorption measurements were performed on 1,3,5-cis hexatriene in cyclohexane and 1-propanol to determine the effect of solvent polarity on the activation energy barrier for ground state single bond isomerization. These measurements conclude that the polar solvent lowers the energy barrier for single bond isomerization allowing conformational relaxation to proceed faster in alcohol solvents compared to alkane solvents. With no perceived polar transition state for single bond isomerization, this result disagrees with the conventional view of solvation and differentiates the single bond isomerization dynamics of polyenes from alkanes. Transient absorption spectroscopy was also utilized to study the solvent effects in the photolysis of various B12 cofactors in different environments. We investigated the solvent dependent photolysis of adenosylcobalamin, methylcobalamin, and cyanocobalamin in water and ethylene glycol as a function of solvent temperature. In comparing the radical cage escape of adenosylcobalamin and cyanocobalamin, we determined a larger than expected hydrodynamic radii for the diffusing radicals in water compared to ethylene glycol, thus making necessary a revised perspective of solvent interaction with the diffusing radical. In addition, we investigated the

  14. Investigations of primary and secondary amine carbamate stability by 1H NMR spectroscopy for post combustion capture of carbon dioxide

    Highlights: ► Carbamate stability constants of series of amines have been measured at (288 to 318) K. ► Standard molar enthalpies and entropies have been determined by van’t Hoff analyses. ► A ΔHmo-ΔSmo plot for carbamate formation gives a linear relationship. ► This relationship provides a guide for the selection of amines for PCC applications. ► Stereochemical effects and intramolecular H-bonding affect carbamate formation. - Abstract: Carbamate formation is one of the major chemical reactions that can occur in solution in the capture of CO2 by amine-based solvents, and carbamate formation makes a significant enthalpy contribution to the absorption-desorption of CO2 that occurs in the absorber/stripper columns of the PCC process. Consequently, the formation of carbamates of selected series of primary and secondary amines over the temperature range (288 to 318) K has been investigated by equilibrium 1H NMR studies, and the stability constants (K9) for the equilibrium: RNH2+HCO3-⇄K9RNHCOO-+H2O are reported. van’t Hoff analyses have resulted in standard molar enthalpies, ΔHmo, and entropies, ΔSmo, of carbamate formation. A ΔHmo-ΔSmo plot generates a linear correlation for carbamate formation (providing a mean standard molar free energy, ΔGmo, for carbamate formation of about −7 kJ · mol−1), and this relationship helps provide a guide to the selection of an amine(s) solvent for CO2 capture, in terms of enthalpy considerations. A linear ΔHmo-ΔSmo plot also occurs for carbamate protonation. The formation of the carbamates has been correlated with systematic changes in composition and structure, and steric effects have been identified by comparing molecular geometries obtained using density functional B3LYP/6-311++G(d,p) calculations. Trends in steric effects have been identified in the series of compounds monoethanolamine (MEA), 1-amino-2-propanol, 2-amino-1-propanol (AP) and 2-amino-2-methyl-1-propanol (AMP). In the case of 2

  15. Determination and correlation of solubility of tylosin tartrate in alcohol mixtures

    Graphical abstract: Data on (solid + liquid) equilibrium of tylosin tartrate in {methanol + (ethanol, 1-propanol or 2-propanol)} solvents was measured over temperature range from (278.15 to 323.15) K under atmospheric pressure by a gravimetric method. From the experimental results, it can be seen that solubility of tylosin tartrate increases with increasing mass fraction of methanol in mixed solvents at a constant temperature, and increases with increasing temperature at the same mass fraction. The solubility of tylosin tartrate in methanol is higher than in methanol mixture solvents, and in 2-propanol is the lowest. The solubility data were correlated well with modified Apelblat equation, λh equation and van’t Hoff equation, and that modified Apelblat equation was more accurate than λh equation and van’t Hoff equation. Further, the standard enthalpy, standard entropy and standard Gibbs free energy of solution of tylosin tartrate in mixed solvents were calculated according to solubility data and model parameters with modified Apelblat equation and van’t Hoff equation. - Highlights: • The solubility of tylosin tartrate in selected solvents has been obtained in this work. • The results show that the three models agree well with the experimental data. • The modified Apelblat model were more accurate than λh model and van’t Hoff model. • The dissolution enthalpy and entropy of tylosin tartrate were calculated from the solubility data. - Abstract: Data on (solid + liquid) equilibrium of tylosin tartrate in {methanol + (ethanol, 1-propanol or 2-propanol)} solvents will provide essential support for industrial design and further theoretical studies. In this study, the solubility of tylosin tartrate in alcohol mixtures was measured over temperature range from (278.15 to 323.15) K under atmospheric pressure by a gravimetric method. From the experimental results, the solubility of tylosin tartrate in selected solvents noted above was found to increase with

  16. Identification of intact high molecular weight glutenin subunits from the wheat proteome using combined liquid chromatography-electrospray ionization mass spectrometry.

    Bert Lagrain

    Full Text Available The present paper describes a method for the identification of intact high molecular weight glutenin subunits (HMW-GS, the quality determining proteins from the wheat storage proteome. The method includes isolation of HMW-GS from wheat flour, further separation of HMW-GS by reversed-phase high-performance liquid chromatography (RP-HPLC, and their subsequent molecular identification with electrospray ionization mass spectrometry using a quadrupole-time-of-flight mass analyzer. For HMW-GS isolation, wheat proteins were reduced and extracted from flour with 50% 1-propanol containing 1% dithiothreitol. HMW-GS were then selectively precipitated from the protein mixture by adjusting the 1-propanol concentration to 60%. The composition of the precipitated proteins was first evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with Coomassie staining and RP-HPLC with ultraviolet detection. Besides HMW-GS (≥65%, the isolated proteins mainly contained ω5-gliadins. Secondly, the isolated protein fraction was analyzed by liquid chromatography-mass spectrometry. Optimal chromatographic separation of HMW-GS from the other proteins in the isolated fraction was obtained when the mobile phase contained 0.1% trifluoroacetic acid as ion-pairing agent. Individual HMW-GS were then identified by determining their molecular masses from the high-resolution mass spectra and comparing these with theoretical masses calculated from amino acid sequences. Using formic acid instead of trifluoroacetic acid in the mobile phase increased protein peak intensities in the base peak mass chromatogram. This allowed the detection of even traces of other wheat proteins than HMW-GS in the isolated fraction, but the chromatographic separation was inferior with a major overlap between the elution ranges of HMW-GS and ω-gliadins. Overall, the described method allows a rapid assessment of wheat quality through the direct determination of the HMW-GS composition and

  17. Enzymatic resolution of (R,S-ibuprofen and (R,S-ketoprofen by microbial lipases from native and commercial sources Resolução enzimática do (R,S-ibuprofeno e (R,S-cetoprofeno por lipases microbianas de fontes nativas e comerciais

    Patrícia de Oliveira Carvalho

    2006-09-01

    Full Text Available The enantioselectivity (E of native lipases from Aspergillus niger, Aspergillus terreus, Fusarium oxysporum, Mucor javanicus, Penicillium solitum and Rhizopus javanicus in the resolution of (R,S-ibuprofen and (R,S-ketoprofenenantiomers by esterification reaction with 1-propanol in isooctane was compared with known commercial Candida rugosa (Sigma and Candida antarctica (Novozym®435 lipases. In the resolution of (R,S-ibuprofen, C. rugosa lipase showed good selectivity (E = 12 while Novozym®435 (E = 6.7 and A. niger (E = 4.8 lipases had intermediate selectivities. Other enzymes were much less selective (E around 2.3 and 1.5, under tested conditions. After preliminary optimization of reaction conditions (water content, enzyme concentration and presence of additives the enantioselectivity of native A. niger lipase could be enhanced substantially (E = 15. All tested lipases showed low selectivity in the resolution of (R,S-ketoprofen because poor ester yields and low enantiomeric excess of the acid remaining were achieved.A enantioseletividade (E das lipases nativas de Aspergillus niger, Aspergillus terreus, Fusarium oxysporum, Mucor javanicus, Penicillium solitum e Rhizopus javanicus na resolução dos enantiômeros do (R,S-ibuprofeno e (R,S-cetoprofeno na reação de esterificação com 1-propanol em isoctano foi comparada com as lipases comerciais de Candida rugosa (Sigma e Candida antarctica (Novozym®435. A lipase de C. rugosa mostrou boa enantioseletividade (E = 12 comparada com as da Novozym®435 (E = 6.7, de A. niger (E=4.8 e com as outras lipases que foram muito menos seletivas (E por volta de 2.3 e 1.5 na resolução do (R,S-ibuprofeno, dentro das condições testadas. Após uma otimização preliminar das condições da reação (conteúdo de água, concentração da enzima e presença de aditivos a enantioseletividade da lipase de A. niger pôde ser substancialmente aumentada (E = 15. Todas as lipases testadas mostraram baixa

  18. Protonation thermodynamics of some aminophenol derivatives in NaCl(aq) (0 ≤ I ≤3 mol . kg-1) at T = 298.15 K

    Highlights: → Protonation thermodynamics of four aminophenol derivatives were determined. → Dependence on ionic strength was analysed by using different models. → Neutral species activity coefficient was determined by distribution measurements. → Acid-base behaviour of this ligand class was modelled. - Abstract: The acid-base properties of four aminophenol derivatives, namely m-aminophenol (L1), 4-amino-2-hydroxytoluene (L2), 2-amino-5-ethylphenol (L3) and 5-amino-4-chloro-o-cresol (L4), are studied by potentiometric and titration calorimetric measurements in NaCl(aq) (0 ≤ I ≤ 3 mol . kg-1) at T = 298.15 K. The dependence of the protonation constants on ionic strength is modelled by the Debye-Hueckel, SIT (Specific ion Interaction Theory) and Pitzer equations. Therefore, the values of protonation constants at infinite dilution and the relative interaction coefficients are calculated. The dependence of protonation enthalpies on ionic strength is also determined. Distribution (2-methyl-1-propanol/aqueous solution) measurements allowed us to determine the Setschenow coefficients and the activity coefficients of neutral species. Experimental results show that these compounds behave in a very similar way, and common class parameters are reported, in particular for the dependence on ionic strength of both protonation constants and protonation enthalpies.

  19. Study of surface tension and surface properties of binary systems of DMSO with long chain alcohols at various temperatures

    Highlights: • Surface tension of binary mixtures of alcohol/DMSO determined. • Surface mole fraction and surface thermodynamic parameters were calculated. • The surface tension data of binary mixtures were correlated with FLW, LWW and MS models. -- Abstract: Surface tensions of binary mixtures of DMSO (dimethyl sulphoxide) with a series of long chain aliphatic alcohols (1-propanol, 1-butanol, and 1-hexanol) were measured as a function of composition using the ring detachment method in the temperature range between (288.15 and 328.15) K. The surface tension results are used to describe quantitatively the nature, properties, and compositions of surface layers in binary liquid mixtures. The temperature influence on the behaviour of surface tensions and surface properties of binary mixtures has often been used to obtain information about solute structural effects on DMSO. The surface tension of the above mentioned binary systems were correlated with empirical and thermodynamic based models. The average relative error obtained from the comparison of experimental and calculated surface tension values for 15 binary systems with three models is less than 1%. In addition to finding more information about the surface structure of binary mixtures, surface mole fraction was calculated using an extended Langmuir model (EL). The temperature dependence of σ at fixed composition of solutions was used to estimate surface enthalpy, Hs, and surface entropy, Ss. The results provide information on the molecular interactions between the unlike molecules that exist at the surface and the bulk

  20. A Sphingolipid Inhibitor Induces a Cytokinesis Arrest and Blocks Stage Differentiation in Giardia lamblia▿

    Sonda, Sabrina; Štefanić, Saša; Hehl, Adrian B.

    2008-01-01

    Sphingolipid biosynthesis pathways have recently emerged as a promising target for therapeutic intervention against pathogens, including parasites. A key step in the synthesis of complex sphingolipids is the glucosylation of ceramide, mediated by glucosylceramide (GlcCer) synthase, whose activity can be inhibited by PPMP (1-phenyl-2-palmitoylamino-3-morpholino-1-propanol). In this study, we investigated whether PPMP inhibits the proliferation and differentiation of the pathogenic parasite Giardia lamblia, the major cause of parasite-induced diarrhea worldwide. PPMP was found to block in vitro parasite replication in a dose-dependent manner, with a 50% inhibitory concentration of 3.5 μM. The inhibition of parasite replication was irreversible at 10 μM PPMP, a concentration that did not affect mammalian cell metabolism. Importantly, PPMP inhibited the completion of cell division at a specific stage in late cytokinesis. Microscopic analysis of cells incubated with PPMP revealed the aberrant accumulation of cellular membranes belonging to the endoplasmic reticulum network in the caudal area of the parasites. Finally, PPMP induced a 90% reduction in G. lamblia differentiation into cysts, the parasite stage responsible for the transmission of the disease. These results show that PPMP is a powerful inhibitor of G. lamblia in vitro and that as-yet-uncharacterized sphingolipid biosynthetic pathways are potential targets for the development of anti-G. lamblia agents. PMID:18086854

  1. A sphingolipid inhibitor induces a cytokinesis arrest and blocks stage differentiation in Giardia lamblia.

    Sonda, Sabrina; Stefanic, Sasa; Hehl, Adrian B

    2008-02-01

    Sphingolipid biosynthesis pathways have recently emerged as a promising target for therapeutic intervention against pathogens, including parasites. A key step in the synthesis of complex sphingolipids is the glucosylation of ceramide, mediated by glucosylceramide (GlcCer) synthase, whose activity can be inhibited by PPMP (1-phenyl-2-palmitoylamino-3-morpholino-1-propanol). In this study, we investigated whether PPMP inhibits the proliferation and differentiation of the pathogenic parasite Giardia lamblia, the major cause of parasite-induced diarrhea worldwide. PPMP was found to block in vitro parasite replication in a dose-dependent manner, with a 50% inhibitory concentration of 3.5 muM. The inhibition of parasite replication was irreversible at 10 muM PPMP, a concentration that did not affect mammalian cell metabolism. Importantly, PPMP inhibited the completion of cell division at a specific stage in late cytokinesis. Microscopic analysis of cells incubated with PPMP revealed the aberrant accumulation of cellular membranes belonging to the endoplasmic reticulum network in the caudal area of the parasites. Finally, PPMP induced a 90% reduction in G. lamblia differentiation into cysts, the parasite stage responsible for the transmission of the disease. These results show that PPMP is a powerful inhibitor of G. lamblia in vitro and that as-yet-uncharacterized sphingolipid biosynthetic pathways are potential targets for the development of anti-G. lamblia agents. PMID:18086854

  2. Toxicity in relation to mode of action for the nematode Caenorhabditis elegans: Acute-to-chronic ratios and quantitative structure-activity relationships.

    Ristau, Kai; Akgül, Yeliz; Bartel, Anna Sophie; Fremming, Jana; Müller, Marie-Theres; Reiher, Luise; Stapela, Frederike; Splett, Jan-Paul; Spann, Nicole

    2015-10-01

    Acute-to-chronic ratios (ACRs) and quantitative structure-activity relationships (QSARs) are of particular interest in chemical risk assessment. Previous studies focusing on the relationship between the size or variation of ACRs to substance classes and QSAR models were often based on data for standard test organisms, such as daphnids and fish. In the present study, acute and chronic toxicity tests were performed with the nematode Caenorhabditis elegans for a total of 11 chemicals covering 3 substance classes (nonpolar narcotics: 1-propanol, ethanol, methanol, 2-butoxyethanol; metals: copper, cadmium, zinc; and carbamates: methomyl, oxamyl, aldicarb, dioxacarb). The ACRs were variable, especially for the carbamates and metals, although there was a trend toward small and less variable ACRs for nonpolar narcotic substances. The octanol-water partition coefficient was a good predictor for explaining acute and chronic toxicity of nonpolar narcotic substances to C. elegans, but not for carbamates. Metal toxicity could be related to the covalent index χm2r. Overall, the results support earlier results from ACR and QSAR studies with standard freshwater test animals. As such C. elegans as a representative of small soil/sediment invertebrates would probably be protected by risk assessment strategies already in use. To increase the predictive power of ACRs and QSARs, further research should be expanded to other species and compounds and should also consider the target sites and toxicokinetics of chemicals. PMID:25994998

  3. Measurement and modeling of osmotic coefficients of binary mixtures (alcohol + 1,3-dimethylpyridinium methylsulfate) at T = 323.15 K

    Research highlights: → The osmotic coefficients of binary mixtures (alcohol + ionic liquid) were determined. → The measurements were carried out with a vapor pressure osmometer at 323.15 K. → The Pitzer-Archer, and the MNRTL models were used to correlate the experimental data. → Mean molal activity coefficients and excess Gibbs free energies were calculated. - Abstract: Measurement of osmotic coefficients of binary mixtures containing several primary and secondary alcohols (1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol) and the pyridinium-based ionic liquid 1,3-dimethylpyridinium methylsulfate were performed at T = 323.15 K using the vapor pressure osmometry technique, and from experimental data, vapor pressure, and activity coefficients were determined. The extended Pitzer model modified by Archer, and the NRTL model modified by Jaretun and Aly (MNRTL) were used to correlate the experimental osmotic coefficients, obtaining standard deviations lower than 0.017 and 0.054, respectively. From the parameters obtained with the extended Pitzer model modified by Archer, the mean molal activity coefficients and the excess Gibbs free energy for the studied binary mixtures were calculated. The effect of the cation is studied comparing the experimental results with those obtained for the ionic liquid 1,3-dimethylimidazolium methylsulfate.

  4. Synthesis and characterization of a tetranuclear copper(Ⅱ) complex with a chiral Schiff base ligand

    Hua Xiang; Long Jiang; Huan-Yong Li; Xiao-Dan Zheng; YU Li

    2013-01-01

    The title complex l-[CuⅡ4(Hvap)2(vap)2(MeOH)2](ClO4)2 1 has been synthesized and characterized by EA,IR,TGA,solid-state CD spectra and X-ray single-crystal analyses (I-H2vap:a Schiff base ligand derived from the condensation of o-vanillin and 1-2-amino-3-phenyl-1-propanol).Complex 1 crystallizes in monoclinic system,chiral space group P21 with a=10.4257(18),b=21.695(4),c=15.721(3) (A),β =94.443(3)°,V=3545.1 (11) (A)3,Z =2,Cu4C7oH78N4O22Cl2,Mr =1652.42,Dc =1.548 g/cm3,F(0 0 0) =1704 and μ(MoKα) =1.338 mm-1.The final R =0.0682 and wR =0.1420 for 6170 observed reflections with I > 2σ(Ⅰ) and R =0.1775 and wR =0.1830 for all data.The structure of complex 1 contains a boat-shaped {Cu4O4} motif.The solid-state CD spectra confirm the chiral nature of complex 1.

  5. Production of CaCO3/hyperbranched polyglycidol hybrid films using spray-coating technique.

    Malinova, Kalina; Gunesch, Manfred; Montero Pancera, Sabrina; Wengeler, Robert; Rieger, Bernhard; Volkmer, Dirk

    2012-05-15

    Biomineralizing organisms employ macromolecules and cellular processing strategies in order to produce highly complex composite materials such as nacre. Bionic approaches translating this knowledge into viable technical production schemes for a large-scale production of biomimetic hybrid materials have met with limited success so far. Investigations presented here thus focus on the production of CaCO(3)/polymer hybrid coatings that can be applied to huge surface areas via reactive spray-coating. Technical requirements for simplicity and cost efficiency include a straightforward one-pot synthesis of low molecular weight hyperbranched polyglycidols (polyethers of 2,3-epoxy-1-propanol) as a simple mimic of biological macromolecules. Polymers functionalized with phosphate monoester, sulfate or carboxylate groups provide a means of controlling CaCO(3) particle density and morphology in the final coatings. We employ reactive spray-coating techniques to generate CaCO(3)/hybrid coatings among which vaterite composites can be prepared in the presence of sulfate-containing hyperbranched polyglycidol. These coatings show high stability and remained unchanged for periods longer than 9 months. By employing carboxylate-based hyperbranched polyglycidol, it is possible to deposit vaterite-calcite composites, whereas phosphate-ester-based hyperbranched polyglycidol leads to calcite composites. Nanoindentation was used to study mechanical properties, showing that coatings thus obtained are slightly harder than pure calcite. PMID:22386308

  6. Potencial de biocatálise enantiosseletiva de lipases microbianas Potential of enantioselective biocatalysis by microbial lipases

    Patrícia de O. Carvalho

    2005-08-01

    Full Text Available Microbial lipases have a great potential for commercial applications due to their stability, selectivity and broad substrate specificity because many non-natural acids, alcohols or amines can be used as the substrate. Three microbial lipases isolated from Brazilian soil samples (Aspergillus niger; Geotrichum candidum; Penicillium solitum were compared in terms of their stability and as biocatalysts in the enantioselective esterification using racemic substrates in organic medium. The lipase from Aspergillus niger showed the highest activity (18.2 U/mL and was highly thermostable, retaining 90% and 60% activity at 50 ºC and 60 ºC after 1 hour, respectively. In organic medium, this lipase provided the best results in terms of enantiomeric excess of the (S-active acid (ee = 6.1% and conversion value (c = 20% in the esterification of (R,S-ibuprofen with 1-propanol in isooctane. The esterification reaction of the racemic mixture of (R,S-2-octanol with decanoic acid proceeded with high enantioselectivity when lipase from Aspergillus niger (E = 13.2 and commercial lipase from Candida antarctica (E = 20 were employed.

  7. Ternary DNA chip based on a novel thymine spacer group chemistry.

    Yang, Yanli; Yildiz, Umit Hakan; Peh, Jaime; Liedberg, Bo

    2015-01-01

    A novel thymine-based surface chemistry suitable for label-free electrochemical DNA detection is described. It involves a simple two-step sequential process: immobilization of 9-mer thymine-terminated probe DNAs followed by backfilling with 9-mer thymine-based spacers (T9). As compared to commonly used organic spacer groups like 2-mercaptoethanol, 3-mercapto-1-propanol and 6-mercapto-1-hexanol, the 9-mer thymine-based spacers offer a 10-fold improvement in discriminating between complementary and non-complementary target hybridization, which is due mainly to facilitated transport of the redox probes through the probe-DNA/T9 layers. Electrochemical measurements, complemented with Surface Plasmon Resonance (SPR) and Quartz Crystal Microbalance (QCM-D) binding analyses, reveal that optimum selectivity between complementary and non-complementary hybridization is obtained for a sensing surface prepared using probe-DNA and backfiller T9 at equimolar concentration (1:1). At this particular ratio, the probe-DNAs are preferentially oriented and easily accessible to yield a sensing surface with favorable hybridization and electron transfer characteristics. Our findings suggest that oligonucleotide-based spacer groups offer an attractive alternative to short organic thiol spacers in the design of future DNA biochips. PMID:25465760

  8. Polypeptide-based aerosol nanoparticles: self-assembly and control of conformation by solvent and thermal annealing.

    Rahikkala, Antti; Junnila, Susanna; Vartiainen, Ville; Ruokolainen, Janne; Ikkala, Olli; Kauppinen, Esko; Raula, Janne

    2014-07-14

    Nanoconfined self-assemblies within aerosol nanoparticles and control of the secondary structures are shown here upon ionically complexing poly(L-lysine) (PLL) with dodecylbenzenesulfonic acid (DBSA) surfactant and using solvents chloroform, 1-propanol, or dimethylformamide. Different solvent volatilities and drying temperatures allowed tuning the kinetics of morphology formation. The supramolecular self-assembly and morphology were studied using cryo-TEM and SEM, and the secondary structures, using FT-IR. Highly volatile chloroform led to the major fraction of α-helical conformation of PLL(DBSA), whereas less volatile solvents or higher drying temperatures led to the increasing fraction of β-sheets. Added drugs budesonide and ketoprofen prevented β-sheet formation and studied PLL(DBSA)-drug nanoparticles were in the α-helical conformation. Preliminary studies showed that ketoprofen released with a slower rate than budesonide which was hypothesized to result from different localization of drugs within the PLL(DBSA) nanoparticles. These results instruct to prepare polypeptide aerosol nanoparticles with internal self-assembled structures and to control the secondary structures by aerosol solvent annealing, which we foresee to be useful, e.g., toward controlling the release of poorly soluble drug molecules. PMID:24848300

  9. Alternative chromatographic system for the quality control of lipophilic technetium-99m radiopharmaceuticals such as [99mTc(MIBI6]+

    D.P. Faria

    2015-01-01

    Full Text Available Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [99mTc(MIBI6]+ as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol:chloroform (25:75, Whatman 3MM paper and ethanol:chloroform (25:75, and the more expensive ITLC-SG and 1-propanol:chloroform (10:90 were suitable systems for the direct determination of radiochemical purity of [99mTc(MIBI6]+ since impurities such as 99mTc-reduced-hydrolyzed (RH, 99mTcO4 - and [99mTc(cysteine2]- complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines.

  10. Molar excess enthalpies at T = 298.15 K for (1-alkanol + dibutylether) systems

    Mozo, Ismael; Garcia De La Fuente, Isaias [G.E.T.E.F., Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, 47071 Valladolid (Spain); Gonzalez, Juan Antonio, E-mail: jagl@termo.uva.e [G.E.T.E.F., Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, 47071 Valladolid (Spain); Cobos, Jose Carlos [G.E.T.E.F., Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, 47071 Valladolid (Spain)

    2010-01-15

    Molar excess enthalpies, H{sub m}{sup E}, at T = 298.15 K and atmospheric pressure have been measured using a microcalorimeter Tian-Calvet for the (methanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-octanol, or 1-decanol + dibutylether) systems. Experimental results have been compared with those obtained from the ERAS, DISQUAC, and Dortmund UNIFAC models. DISQUAC and ERAS yield similar H{sub m}{sup E}, results. Larger differences between experimental and calculated H{sub m}{sup E}, values are obtained from UNIFAC. ERAS represents quite accurately the excess molar volumes, V{sub m}{sup E}, of these systems. The excess molar internal energy at constant volume, U{sub V,m}{sup E}, is nearly constant for the solutions with the longer 1-alkanols. This points out that the different interactional contributions to this magnitude are counterbalanced. Interactions between unlike molecules are stronger in methanol systems. The same behaviour is observed in mixtures with dipropylether.

  11. ZrO2 coatings on stainless steel by aerosol thermal spraying

    Zirconia coatings, with a wide range of thickness (1 to 80 μ) have been obtained by spraying a ZrO2 sol with an oxyacetylenic flame, on stainless steel substrates. The sol was prepared by mixing Zr-n-propoxide and acetic acid in order to obtain a zirconium oxyacetate precipitate, which was filtrated, washed with 1-propanol, dryed and subjected to an hydrothermal treatment. A new sol-gel based ceramic deposition process , aerosol thermal spraying was developed based on previous thermal spray work. A compressed air spray gun was used to produce a fine aerosol flow which was injected in the flame of the thermal spray torch and deposited on polished and sand blasted substrates. This original technique allows simultaneous spraying, drying and partial sintering of the zirconia nanometric particles. The maximum working temperature necessary to yield a resistant coating is 1000 deg C. This method produced crack-free homogeneous layers of monoclinic ZrO2 with good adhesion to the substrate and low porosity, as shown by X-ray diffraction and scanning electron microscopy. Oxidation test, carried out by heat treatments in air atmosphere at 800 deg C indicated good protection, mainly for low thickness coatings deposited in polished substrates. This original deposition technique offers several advantages when compared with classical thermal spraying techniques, such as plasma spraying. Copyright (1998) AD-TECH - International Foundation for the Advancement of Technology Ltd

  12. Volumetric, acoustic, and viscometric studies of molecular interactions in binary mixtures of dipropylene glycol dimethyl ether with 1-alkanols at 298.15 K

    Pal, Amalendu [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)], E-mail: palchem@sify.com; Gaba, Rekha [Department of Chemistry, Kurukshetra University, Kurukshetra 136 119 (India)], E-mail: rekhagaba@gmail.com

    2008-05-15

    In this work densities, {rho}, ultrasonic speeds, u, and viscosities, {eta}, have been measured over the whole composition range for the binary mixtures of dipropylene glycol dimethyl ether (DPGDME) with ethanol, 1-propanol, 1-pentanol, and 1-heptanol at 298.15 K along with the properties of the pure components. By using the experimental values of {rho}, u, and {eta}, excess molar volume, V{sub m}{sup E}, deviations in viscosity, {delta}{eta}, excess free energy of activation for viscous flow, {delta}G*{sup E}, excess molar isentropic compressibility, K{sub S,m}{sup E}, deviation of the speeds of sound, u{sup D}, from their ideal values u{sup id} in an ideal mixtures, apparent molar volume, and apparent molar compressibility, V-bar{sub {phi}}{sub ,i}{sup 0} and K-bar{sub {phi}}{sub ,i}{sup 0} of the components at infinite dilution have been calculated. Finally, the experimental viscosity data have been correlated by the methods of Grunberg-Nissan, Hind, Tamura-Kurata, Chaudhry, Auslaender, Heric, and with McAllister correlations.

  13. Rapid and sensitive analysis of three polyphenols in tobacco by CE using homemade C(4)D with a mini detection cell.

    Xie, Fuwei; Zhang, Yanhao; Zheng, Bo; Xu, Feifei; Su, Jianpo; Lu, Yanyan; Zeng, Fanya; Zhang, Bin; Guo, Yaxiao; Zhang, Shusheng

    2012-08-01

    A rapid, sensitive, and practical CE with C(4) D detection was developed for the analysis of three polyphenols (rutin, scopoletin, and chlorogenic acid) in tobacco samples. The constructed mini detection cell (12 mm × 10 mm × 10 mm) of C(4) D featured with small inner cell volume (∼2 nL), smaller noise (<0.9 mV), repeatability, high strength and durableness. Three polyphenols were ultrasonically extracted with methanol-water (70:30, v/v) solution following SPE cleanup. The CE method was optimized with the running buffer of 150 mmol L(-1) 2-amino-2-methyl-1-propanol (pH 11.2), and the applied separation voltage of +20 kV over a capillary of 50 μm id × 375 μm od × 50 cm (38 cm to the C(4) D window, 41.5 cm to the UV detector window), which gave a baseline separation of three polyphenols within ca. 6 min. The method provided the limits of quantification (S/N = 10) at about 0.08-0.15 μg g(-1) for three polyphenols, whereas the overall recoveries ranged from 82% to 88%. The proposed method has been successfully applied to measure three polyphenols in the actual tobacco samples, and their contents were calculated and evaluated. PMID:22887165

  14. Gene cloning and catalytic characterization of cold-adapted lipase of Photobacterium sp. MA1-3 isolated from blood clam.

    Kim, Young Ok; Khosasih, Vivia; Nam, Bo-Hye; Lee, Sang-Jun; Suwanto, Antonius; Kim, Hyung Kwoun

    2012-12-01

    A lipase-producing Photobacterium strain (MA1-3) was isolated from the intestine of a blood clam caught at Namhae, Korea. The lipase gene was cloned by shotgun cloning and encoded 340 amino acids with a molecular mass of 38,015 Da. It had a very low sequence identity with other bacterial lipases, with the exception of that of Photobacterium lipolyticum M37 (83.2%). The MA1-3 lipase was produced in soluble form when Escherichia coli cells harboring the gene were cultured at 18°C. Its optimum temperature and pH were 45°C and pH 8.5, respectively. Its activation energy was calculated to be 2.69 kcal/mol, suggesting it to be a cold-adapted lipase. Its optimum temperature, temperature stability, and substrate specificity were quite different from those of M37 lipase, despite the considerable sequence similarities. Meanwhile, MA1-3 lipase performed a transesterification reaction using olive oil and various alcohols including methanol, ethanol, 1-propanol, and 1-butanol. In the presence of t-butanol as a co-solvent, this lipase produced biodiesel using methanol and plant or waste oils. The highest biodiesel conversion yield (73%) was achieved using waste soybean oil and methanol at a molar ratio of 1:5 after 12 h using 5 units of lipase. PMID:22841866

  15. Oxidation, Reduction, and Condensation of Alcohols over (MO3)3 (M=Mo, W) Nanoclusters

    Fang, Zongtang; Li, Zhenjun; Kelley, Matthew S.; Kay, Bruce D.; Li, Shenggang; Hennigan, Jamie M.; Rousseau, Roger J.; Dohnalek, Zdenek; Dixon, David A.

    2014-10-02

    The reactions of deuterated methanol, ethanol, 1-propanol, 1-butanol, 2-propanol, 2-butanol and t-butanol over cyclic (MO3)3 (M = Mo, W) clusters were studied experimentally with temperature programmed desorption (TPD) and theoretically with coupled cluster CCSD(T) theory and density functional theory. The reactions of two alcohols per M3O9 cluster are required to provide agreement with experiment for D2O release, dehydrogenation and dehydration. The reaction begins with the elimination of water by proton transfers and forms an intermediate dialkoxy species which can undergo further reaction. Dehydration proceeds by a β hydrogen transfer to a terminal M=O. Dehydrogenation takes place via an α hydrogen transfer to an adjacent MoVI = O atom or a WVI metal center with redox involved for M = Mo and no redox for M = W. The two channels have comparable activation energies. H/D exchange to produce alcohols can take place after olefin is released or via the dialkoxy species depending on the alcohol and the cluster. The Lewis acidity of the metal center with WVI being larger than MoVI results in the increased reactivity of W3O9 over Mo3O9 for dehydrogenation and dehydration.

  16. Adsorption and Reaction of C1-C3 Alcohols over CeOx(111) Thin Films

    D Mullins; S Senanayake; T Chen

    2011-12-31

    This study reports the interaction of methanol, ethanol, 1-propanol, and 2-propanol with well-ordered CeO{sub 2}(111) thin film surfaces. All of the alcohols adsorb at low temperature by forming alkoxy and hydroxyl species on the surface. On fully oxidized CeO{sub 2}(111), recombination occurs between some of the alkoxys and hydroxyls, resulting in alcohol desorption near 220 K. At the same temperature, some of the surface hydroxyls disproportionate to produce water and the loss of lattice O. The remaining alkoxys react above 550 K. The primary alcohols favor dehydrogenation products (aldehydes). There is a net loss of O from the system, resulting in a reduction of the ceria. The secondary alcohol, 2-propanol, undergoes primarily dehydration, producing propene with no net change in the cerium oxidation state. Reduced CeO{sub x}(111) competes with the gaseous products for available O. Little or no water is produced. The reaction selectivity for the C{sub 2} and C{sub 3} alcohols shifts toward favoring dehydration products. The loss of O from the alcohols leads to oxidation of the reduced ceria. Compared with the oxidized surface, the alkene desorption shifts to lower temperature, whereas the aldehyde desorption shifts to higher temperature. This indicates that, on the reduced surface, it is easier to break the C-O bond but more difficult to break the O-substrate bond.

  17. Comparative studies on the alcohol types presence in Gracilaria sp. and rice fermentation using Sasad

    Mansa, R.; Mansuit, H.; Sipaut, C. S.; Yee, C. F.; Yasir, S. M.

    2016-06-01

    Alternative fuel sources such as biofuels are needed in order to overcome environmental problem caused by fossil fuel consumption. Currently, most biofuel are produced from land based crops and there is a possibility that marine biomass such as macroalgae can be an alternative source for biofuel production. The carbohydrate in macroalgae can be broken down into simple sugar through thermo-chemical hydrolysis and enzymatic hydrolysis. Dilute-acid hydrolysis was believed to be the most available and affordable method. However, the process may release inhibitors which would affect alcohol yield from fermentation. Thus, this work was aimed at investigating if it is possible to avoid this critical pre-treatment step in macroalgae fermentation process by using Sasad, a local Sabahan fermentation agent and to compare the yield with rice wine fermentation. This work hoped to determine and compare the alcohol content from Gracilaria sp. and rice fermentation with Sasad. Rice fermentation was found containing ethanol and 2 - methyl - 1 - propanol. Fermentation of Gracilaria sp. had shown the positive presence of 3 - methyl - 1 - butanol. It was found that Sasad can be used as a fermentation agent for bioalcohol production from Gracilaria sp. without the need for a pretreatment step. However further investigations are needed to determine if pre-treatment would increase the yield of alcohol.

  18. Application of integrated comprehensive/multidimensional gas chromatography with mass spectrometry and olfactometry for aroma analysis in wine and coffee.

    Chin, Sung-Tong; Eyres, Graham T; Marriott, Philip J

    2015-10-15

    Component coelution in chromatographic analysis complicates identification and attribution of individual odour-active volatile molecules in complex multi-component samples. An integrated system incorporating comprehensive two-dimensional gas chromatography (GC × GC) and multidimensional gas chromatography (MDGC), with flame ionisation, olfactometry and mass spectrometry detection was developed to circumvent data correlation across different systems. Identification of potent odorants in Shiraz wine and the headspace of ground coffee are demonstrated as selected applications. Multiple solid-phase microextraction (SPME) sampling with GC-O located odour-active regions; GC × GC established the complexity of odour-active regions; MDGC provided high-resolution separation for each region; simultaneous 'O' and MS detection completed the analysis for target resolved peaks. Seven odour regions in Shiraz were analysed with MDGC-O/MS detection, revealing 11 odour volatiles through matching of mass spectrometry and retention indices from both separating dimensions, including acetic acid; octen-3-ol; ethyl octanoate; methyl-2-oxo-nonanoate; butanoic acid, 2-methylbutanoic acid, and 3-methylbutanoic acid; 3-(methylthio)-1-propanol; hexanoic acid; β-damascenone; and ethyl-3-phenylpropanoate. A capsicum odour in ground coffee was identified as 2-methoxy-3-isobutylpyrazine with a 5-fold increase in S/N of the odorant when acquired using a 6-time cumulative SPME sampling approach. PMID:25952879

  19. Characterization of key odorants in Chinese chixiang aroma-type liquor by gas chromatography-olfactometry, quantitative measurements, aroma recombination, and omission studies.

    Fan, Haiyan; Fan, Wenlai; Xu, Yan

    2015-04-15

    Chixiang aroma-type liquor is extensively welcomed by consumers owing to its typical fatty aroma, particularly in southern China. To our knowledge, no comprehensive characterization of aroma and flavor from chixiang aroma-type liquor has been published. It is still a confused question which components are the most important in characterizing its unique aroma. A total of 56 odorants were identified in chixiang aroma-type liquor by aroma extract dilution analysis (AEDA), and in different quantitative measurements, 34 aroma compounds were further demonstrated as important odorants according to odor activity values (OAVs). Furthermore, this research suggested that the aroma of chixiang aroma-type finished liquor could be successfully reconstituted by mixing 34 aroma compounds in the concentrations measured. Omission experiments further confirmed (E)-2-nonenal as the key odorant and revealed the significance of (E)-2-octenal and 2-phenylethanol for the overall aroma of chixiang aroma-type liquor. 3-(Methylthio)-1-propanol (methionol), diethyl 1,7-heptanedioate (diethyl pimelate), diethyl 1,8-octanedioate (diethyl suberate), and diethyl 1,9-nonanedioate (diethyl azelate), identified as the characteristic aromas of chixiang aroma-type liquor in 1995, had no effects on aroma based on omission/addition experiments. PMID:25797496

  20. Safety Evaluation of the Grape Marc Spirit by GC-FID Analysis

    Teodora Coldea

    2013-11-01

    Full Text Available There were investigated grape marc spirits regarding their safety on consumers. Major volatile compounds which present risk to human health (such as methanol, furfural, and acetaldehyde and ethyl alcohol content were compared to European Union Regulation and other values found in previous studies.  The aim of our study was to evaluate the safety of grape marc spirits considering their content in major volatile compounds by comparison with the requirements of European Union Regulation. We investigated the ethyl alcohol content by electronic densimetry and 10 major volatile compounds (acetaldehyde, ethyl acetate, methanol, 1-propanol, 1-butanol, 2-butanol, isobutyl alcohol, isoamyl alcohol, amyl active alcohol and furfural by Gas Chromatography coupled with Flame Ionization Detector. We used reference chemicals to identify these compounds and 3-pentanol as internal standard to quantify the volatiles. Results were compared with the requirements of European Union Regulation. All major volatile compounds registered values in accordance to EU Regulation and the grape pomace spirits samples do not present any kind of risk for consumption.

  1. Thermodynamic properties of binary mixtures of 2,2,2-trifluoroethanol with water or alkanols at T=298.15K

    Minamihonoki, Takashi [Graduate School of Science and Engineering, Tokyo Denki University, Hatoyama, Hiki-gun, Saitama 350-0394 (Japan)]. E-mail: taka-mi@m4.kcn.ne.jp; Ogawa, Hideo [Graduate School of Science and Engineering, Tokyo Denki University, Hatoyama, Hiki-gun, Saitama 350-0394 (Japan); Nomura, Hiroyasu [Graduate School of Science and Engineering, Tokyo Denki University, Hatoyama, Hiki-gun, Saitama 350-0394 (Japan); Murakami, Sachio [Frontier Research and Development Center, Tokyo Denki University, Hatoyama, Hiki-Gun, Saitama 350-0394 (Japan)

    2007-07-01

    Excess molar enthalpies (H{sub m}{sup E}) and excess molar volume (V{sub m}{sup E}) at T=298.15K for binary mixtures of {l_brace}2,2,2-trifluoroethanol (TFE)+water or alcohols (methanol, ethanol, 1-propanol){r_brace} were obtained by calorimetry and densimetry. Excess molar enthalpies for the (TFE+water) system showed endothermic mixing, except for the low TFE concentration range (x{sub 1}<0.1) in which they showed exothermic one. On the other hand, excess molar volumes for this system were negative over the whole range of concentration. Excess molar enthalpies for all the (TFE+alcohol) systems were exothermic over the whole range of concentration and decrease in absolute value with increase of the carbon number of the alkyl group in the alcohol molecules (n{sub C}). Excess molar volumes were positive over the whole range of concentration and increase with n{sub C}. Moreover, we estimated excess partial molar enthalpy (H{sub m,i}{sup E,{approx}}) and volume (V{sub m,i}{sup E,{approx}}) at infinite dilution from the experimental results. These results were discussed qualitatively from the viewpoint of the intermolecular interactions in the pure component liquids and the mixtures.

  2. Transmission of low-energy electrons (0-15eV) through thin films of ethers, ketones, alcohols, and ice

    The transmission of low-energy electrons (0-15 eV) through 10-100 A films of ethers, ketones, alcohols, and ice has been studied. Structures are indicated by electron current Isub(t) transmitted through a thin film as a function of the incident electron energy Vsub(i), displayed as dIsub(t)/dVsub(i), vs. V sub(i). With increasing the film thickness, a decrease of the height of the first peak (due to injection of electrons in the film) and an appearance of a second peak are observed for ethers and alcohols. The energies of quasifree electron state Vsub(o) are determined by measuring the energy of the second peak from the first peak for solid diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-pentanol, 1-hexanol, and 1-nonanol. For acetone, diethyl ketone, dimethyl sulfoxide, and ice, neither a decrease of the first peak nor an appearance of a second peak is observed, indicating that these compounds have negative Vsub(o) values. From the energy of the onsets of broad negative peaks appeared at asymptotically equls 14 eV for ethers and alcohols, the solid phase ionization energies Isub(s) and the polarization energies of cations P+ by the solid media are determined. (author)

  3. Anoxic radiation protection of bacterial spores in suspension

    Several compounds (nine alcohols, sodium formate, and CO2 gas) have been tested for an ability to alter the anoxic radiation sensitivity of Bacillus megaterium spores, irradiated in suspension. Some of the additives protected (allyl alcohol, ethanol, glycerol, methanol, 1-propanol, 2-propanol, sodium formate and CO2); some did not (1-amyl alcohol, benzyl alcohol, and t-butanol). A correlation exists between anoxic radiation protection and the ability of the additive to react with a water-derived radical and form a radical at the α-hydroxy position. Only those additives that form a radical at this site showed an ability to protect. As a test of the relevance of this correlation between radiation protection and the formation of an α-hydroxy radical, OH competition experiments were run between methanol and t-amyl alcohol. These results showed that methanol partially loses its ability to protect when the competition for OH favors t-amyl alcohol about 4.3:1. These initial results suggest that the correlation is significant, although the exact mechanisms for protection are not known

  4. Multiple pesticide analysis in wine by MEKC combined with solid-phase microextraction and sample stacking.

    Ravelo-Pérez, Lidia M; Hernández-Borges, Javier; Borges-Miquel, Teresa M; Rodríguez-Delgado, Miguel A

    2007-11-01

    In this work, a new method for the determination in white wines of 12 pesticides widely used in vine cultivars (namely, carbendazim, pirimicarb, metalaxyl, pyrimethanil, procymidone, nuarimol, azoxystrobin, tebufenozide, fenarimol, benalaxyl, penconazole, and tetradifon) using solid-phase microextraction (SPME) and MEKC with diode-array detection (DAD) was developed. The MEKC buffer consisted of 100 mM sodium tetraborate and 30 mM SDS at pH 8.5 with 6% v/v 1-propanol. Reversed-electrode polarity stacking mode (REPSM) was applied as on-line preconcentration strategy. In order to carry out an effective and sensitive determination of these pesticides in wine samples, an off-line SPME procedure was optimized by means of an experimental design. After studying the extraction performance of different SPME coatings, PDMS/divinylbenzene (PDMS/DVB) fibers were found the most appropriate for the extraction of most of these pesticides. Carbendazim and metalaxyl could not be extracted from wine samples. Calibration curves for extracted standards and fortified white wines were studied in order to determine the presence of a matrix effect. The combination of both preconcentration procedures (SPME and REPSM) allowed the determination of ten of these pesticides in white wines at concentrations between 0.054 and 0.113 mg/L. (i.e., levels well below the maximum residue limits (MRLs) allowed for these compounds in wine grapes). Ten homemade wines were they analyzed with the optimized method demonstrating the usefulness of the proposed procedure. PMID:17957661

  5. Use of Organic Solvents to Extract Organochlorine Pesticides (OCPs) from Aged Contaminated Soils

    YE Mao; JIN Xin; JIANG Xin; YANG Xing-Lun; SUN Ming-Ming; BIAN Yong-Rong; WANG Fang; GU Cheng-Gang; WEI Hai-Jiang; SONG Yang; WANG Lei

    2013-01-01

    Problems associated with organochlorine pesticide (OCP)-contaminated sites in China have received wide attention.To solve such problems,innovative ex-situ methods of site remediation are urgently needed.We investigated the feasibility of the extraction method with different organic solvents,ethanol,1-propanol,and three fractions of petroleum ether,using a soil collected from Wujiang (WJ),China,a region with long-term contamination of dichlorodiphenyltrichloroethanes (DDTs).We evaluated different influential factors,including organic solvent concentration,washing time,mixing speed,solution-to-soil ratio,and washing temperature,on the removal of DDTs from the WJ soil.A set of relatively better parameters were selected for extraction with 100 mL L-1 petroleum ether (60-90 ℃):washing time of 180 min,mixing speed of 100 r min-1,solution-to-soil ratio of 10:1,and washing temperature of 50 ℃.These selected parameters were also applied on three other seriously OCP-polluted soils.Results demonstrated their broad-spectrum effectiveness and excellent OCP extraction performance on the contaminated soils with different characteristics.

  6. Acid Lipase from Candida viswanathii: Production, Biochemical Properties, and Potential Application

    Alex Fernando de Almeida

    2013-01-01

    Full Text Available Influences of environmental variables and emulsifiers on lipase production of a Candida viswanathii strain were investigated. The highest lipase activity (101.1 U was observed at 210 rpm, pH 6.0, and 27.5°C. Other fermentation parameters analyzed showed considerable rates of biomass yield ( g/h. Addition of soybean lecithin increased lipase production in 1.45-fold, presenting lipase yield ( of 10.061 U/g. Crude lipase presented optimal activity at acid pH of 3.5, suggesting a new lipolytic enzyme for this genus and yeast in general. In addition, crude lipase presented high stability in acid conditions and temperature between 40 and 45°C, after 24 h of incubation in these temperatures. Lipase remained active in the presence of organic solvents maintaining above 80% activity in DMSO, methanol, acetonitrile, ethanol, acetone, 1-propanol, isopropanol, and 2-propanol. Effectiveness for the hydrolysis of a wide range of natural triglycerides suggests that this new acid lipase has high potential application in the oleochemical and food industries for hydrolysis and/or modification of triacylglycerols to improve the nutritional properties.

  7. Acid lipase from Candida viswanathii: production, biochemical properties, and potential application.

    de Almeida, Alex Fernando; Tauk-Tornisielo, Sâmia Maria; Carmona, Eleonora Cano

    2013-01-01

    Influences of environmental variables and emulsifiers on lipase production of a Candida viswanathii strain were investigated. The highest lipase activity (101.1 U) was observed at 210 rpm, pH 6.0, and 27.5°C. Other fermentation parameters analyzed showed considerable rates of biomass yield (Y L/S = 1.381 g/g), lipase yield (Y L/S = 6.892 U/g), and biomass productivity (P X = 0.282 g/h). Addition of soybean lecithin increased lipase production in 1.45-fold, presenting lipase yield (Y L/S ) of 10.061 U/g. Crude lipase presented optimal activity at acid pH of 3.5, suggesting a new lipolytic enzyme for this genus and yeast in general. In addition, crude lipase presented high stability in acid conditions and temperature between 40 and 45°C, after 24 h of incubation in these temperatures. Lipase remained active in the presence of organic solvents maintaining above 80% activity in DMSO, methanol, acetonitrile, ethanol, acetone, 1-propanol, isopropanol, and 2-propanol. Effectiveness for the hydrolysis of a wide range of natural triglycerides suggests that this new acid lipase has high potential application in the oleochemical and food industries for hydrolysis and/or modification of triacylglycerols to improve the nutritional properties. PMID:24350270

  8. Measurements and equation-of-state modelling of thermodynamic properties of binary mixtures of 1-butyl-1-methylpyrrolidinium tetracyanoborate ionic liquid with molecular compounds

    Highlights: • Solubility data for 10 molecular solvents in [BMPYR][TCB] are reported. • Excess enthalpies for 7 molecular solvents in [BMPYR][TCB] are given. • Thermodynamic modelling with PC-SAFT equation of state is presented. - Abstract: This paper presents a comprehensive thermodynamic study of binary mixtures formed by 1-butyl-1-methylpyrrolidinium tetracyanoborate ionic liquid and hydrocarbons (n-heptane, benzene, toluene, ethylbenzene), thiophene and alcohols (methanol, ethanol, 1-propanol, 1-butanol, 1-hexanol, 1-octanol, 1-decanol and 1-dodecanol). An impact of chemical structure of molecular compounds on their solubility in the ionic liquid and excess enthalpies of mixing is discussed. Furthermore, modelling of the measured properties by using perturbed-chain statistical associating fluid theory (PC-SAFT) is presented. The theory is applied in both correlative and semi-predictive mode involving temperature-dependent binary corrections fitted to infinite dilution activity coefficients. Solubility curves and excess enthalpies are captured by the model with a reasonable accuracy, when semi-predictive strategy is adopted. Moreover, (liquid + liquid) equilibrium phase diagram in ternary system composed of the investigated ionic liquid, thiophene and n-heptane is predicted with PC-SAFT and then the calculations are confronted with available experimental data. The results indicate that the approach proposed can be perceived as an interesting tool for reproducing the thermodynamic behaviour disclosed by such complex systems as those based on ionic liquids

  9. Neighboring Hetero-Atom Assistance of Sacrificial Amines to Hydrogen Evolution Using Pt-Loaded TiO2-Photocatalyst

    Masahide Yasuda

    2014-05-01

    Full Text Available Photocatalytic H2 evolution was examined using Pt-loaded TiO2-photocatalyst in the presence of amines as sacrificial agents. In the case of amines with all of the carbon attached to the hetero-atom such as 2-aminoethanol, 1,2-diamonoethane, 2-amino-1,3-propanediol, and 3-amino-1,2-propanediol, they were completely decomposed into CO2 and water to quantitatively evolve H2. On the other hand, the amines with both hetero-atoms and one methyl group at the β-positions (neighboring carbons of amino group such as 2-amino-1-propanol and 1,2-diaminopropane were partially decomposed. Also, the photocatalytic H2 evolution using amines without the hetero-atoms at the β-positions such as ethylamine, propylamine, 1-butylamine, 1,3-diaminopropane, 2-propylamine, and 2-butylamine was inefficient. Thus, it was found that the neighboring hetero-atom strongly assisted the degradation of sacrificial amines. Moreover, rate constants for H2 evolution were compared among amines. In conclusion, the neighboring hetero-atom did not affect the rate constants but enhanced the yield of hydrogen evolution.

  10. Oxidation of 2-propanol ligands during collision-induced dissociation of a gas-phase uranyl complex

    van Stipdonk, Michael J.; Chien, Winnie; Anbalagan, Victor; Gresham, Garold L.; Groenewold, Gary S.

    2004-10-01

    We demonstrate, by way of multi-stage tandem mass spectrometry and extensive deuterium labeling, that 2-propanol is converted to acetone, and 2-propoxide to acetaldehyde, when monopositive 2-propanol-coordinated uranyl-ligand cations are subjected to collision-induced dissociation in the gas-phase environment of an ion trap mass spectrometer. A species with formula [(UO2OCH(CH3)2)(HOCH(CH3)2)]+, derived from dissociation of the gas-phase precursor [(UO2NO3)(HOCH(CH3)2)3]+ eliminates two H atoms and CH3 in consecutive stages to generate a monopositive complex composed of the U(V) species UO2+ coordinated by acetone and acetaldehyde, i.e. [UO2+(OC(CH3)2)(OC(H)CH3)]. Dissociation of this latter ion resulted in elimination of the two coordinating carbonyl ligands in two consecutive dissociation stages to leave UO2+. Analogous reactions were not observed for uranyl complexes containing 1-propanol or 2-methyl-2-propanol, or for cationic complexes with divalent metals such as Ni2+, Co2+, Pb2+ and Ca2+. One explanation for these reactions is bond insertion by the metal center in the bis-ligated uranyl complex, which would be expected to have an LUMO consisting of unoccupied 6d-orbitals that would confer transition metal-like behavior on the complex.

  11. Lipid substrate specificity of phosphatidylethanolamine N-methyltransferase of Tetrahymena

    The ciliate protozoan Tetrahymena thermophila forms about 60% of its phosphatidylcholine by methylation of phosphatidylethanolamine with S-adenosylmethionine using the enzyme phosphatidylethanolamine N-methyltransferase. Analogues of ethanolamine or of ethanolamine phosphate are incorporated into the phospholipids of Tetrahymena when cells are cultured in their presence. These compounds, 3-amino-1-propanol, 2-aminoethylphosphonate, 3-aminopropylphosphonate and N,N-dimethylaminoethylphosphonate replace from 50 to 75% of the ethanolamine phosphate in phosphatidylethanolamine. However, analysis of the phospholipids of lipid-altered Tetrahymena showed that none of the phosphatidylethanolamine analogues had been converted to the corresponding phosphatidylcholine analogue. No incorration of [14C-CH3]methionine into the phosphatidylcholine analogues could be demonstrated in vivo, nor was label from [3H-CH3]S-adenosylmethionine incorporated in virto. Thus, only phosphatidylethanolamine and its monomethyl and dimethyl derivatives have been found to be substrates for the phosphatidylethanoiamine N-methyltransferase. The enzyme therefore requires a phospholipid substrate containing an ester linkage between the alkylamine and phosphorus, with the amino group required to be β to the alcohol

  12. Metabolism and disposition of propylene glycol monomethyl ether (PGME) beta isomer in male rats

    Male Fischer 344 rats were given a single po dose of approximately 1 or 8.7 mmol/kg of radiolabelled propylene glycol monomethyl ether (PGME) beta isomer (2-methoxy-1-propanol). After dosing, expired air, excreta, and tissues were analyzed for 14C activity and metabolites in urine were isolated and identified. Approximately 70 to 80% of the 14C was excreted in urine while about 10 to 20% was eliminated as 14CO2 within 48 hr after dosing. The major urinary metabolite was 2-methoxypropionic acid, which accounted for approximately 93 and 79% of the radioactivity in urine from high- and low-dose animals, respectively. A glucuronide conjugate of the PGME beta isomer was also identified in urine; this metabolite accounted for approximately 3 to 4% of the radioactivity in the urine at both dosages. These results indicate that the PGME beta isomer is metabolized via different routes to different types of metabolites in comparison to the PGME alpha isomer. While the two isomers are biotransformed differently, there is a substantial toxicological data base which clearly shows that the commercial grade PGME mixture (2 to 5% beta isomer) has a low degree of biological activity

  13. Volumetric, acoustic, and viscometric studies of molecular interactions in binary mixtures of dipropylene glycol dimethyl ether with 1-alkanols at 298.15 K

    In this work densities, ρ, ultrasonic speeds, u, and viscosities, η, have been measured over the whole composition range for the binary mixtures of dipropylene glycol dimethyl ether (DPGDME) with ethanol, 1-propanol, 1-pentanol, and 1-heptanol at 298.15 K along with the properties of the pure components. By using the experimental values of ρ, u, and η, excess molar volume, VmE, deviations in viscosity, Δη, excess free energy of activation for viscous flow, ΔG*E, excess molar isentropic compressibility, KS,mE, deviation of the speeds of sound, uD, from their ideal values uid in an ideal mixtures, apparent molar volume, and apparent molar compressibility, V-barφ,i0 and K-barφ,i0 of the components at infinite dilution have been calculated. Finally, the experimental viscosity data have been correlated by the methods of Grunberg-Nissan, Hind, Tamura-Kurata, Chaudhry, Auslaender, Heric, and with McAllister correlations

  14. Volatile compounds in whole meal bread crust: The effects of yeast level and fermentation temperature.

    Nor Qhairul Izzreen, M N; Hansen, Se S; Petersen, Mikael A

    2016-11-01

    The influence of fermentation temperatures (8°C, 16°C, and 32°C) and yeast levels (2%, 4%, and 6% of the flour) on the formation of volatile compounds in the crust of whole meal wheat bread was investigated. The fermentation times were regulated to optimum bread height for each treatment. The volatile compounds were extracted by dynamic headspace extraction and analyzed by gas chromatography-mass spectrometry. The results were evaluated using multivariate data analysis and ANOVA. In all crust samples 28 volatile compounds out of 58 compounds were identified and the other 30 compounds were tentatively identified. Higher fermentation temperatures promoted the formation of Maillard reaction products 3-methyl-1-butanol, pyrazine, 2-ethylpyrazine, 2-ethyl-3-methylpyrazine, 2-vinylpyrazine, 3-hydroxy-2-butanone, 3-(methylsulfanyl)-propanal, and 5-methyl-2-furancarboxaldehyde whereas at lower temperature (8°C) the formation of 2- and 3-methylbutanal was favored. Higher levels of yeast promoted the formation of 3-methyl-1-butanol, 2-methyl-1-propanol and 3-(methylsulfanyl)-propanal, whereas hexanal was promoted in the crust fermented with lower yeast level. PMID:27211683

  15. Influence of the Hydrothermal Method Growth Parameters on the Zinc Oxide Nanowires Deposited on Several Substrates

    Concepción Mejía-García

    2014-01-01

    Full Text Available We report the synthesis of ZnO nanowires grown on several substrates (PET, glass, and Si using a two-step process: (a preparation of the seed layer on the substrate by spin coating, from solutions of zinc acetate dihydrate and 1-propanol, and (b growth of the ZnO nanostructures by dipping the substrate in an equimolar solution of zinc nitrate hexahydrate and hexamethylenetetramine. Subsequently, films were thermally treated with a commercial microwave oven (350 and 700 W for 5, 20, and 35 min. The ZnO nanowires obtained were characterized structurally, morphologically, and optically using XRD, SEM, and UV-VIS transmission, respectively. XRD patterns spectra revealed the presence of Zn(OH2 on the films grown on glass and Si substrates. A preferential orientation along c-axis directions for films grown on PET substrate was observed. An analysis by SEM revealed that the growth of the ZnO nanowires on PET and glass is better than the growth on Si when the same growth parameters are used. On glass substrates, ZnO nanowires less than 50 nm in diameter and between 200 nm and 1200 nm in length were obtained. The ZnO nanowires band gap energy for the films grown on PET and glass was obtained from optical transmission spectra.

  16. Measurement, correlation and dissolution thermodynamics of biological active chalcone in organic solvents at different temperatures

    Highlights: • Solubility of chalcone in maximum in non-polar solvent chloroform. • Among different alcohols, Solubility is maximum in 1-butanol and minimum in methanol. • The positive ΔH and ΔG suggest endothermic and spontaneous dissolution process. • The negative entropy in THF and ethyl acetate suggests more ordered structure in these solutions. • The positive entropy suggests less ordered structure in solutions. - Abstract: The present study reports the synthesis, characterization and solubility of (E)-2-(4-chlorobenzylidene)-3,4-dihydronaphthalen-1(2H)-one. The compound was synthesized by standard process. The purity was monitored by TLC and confirmation of structure was done by using mass, IR and 1H NMR spectral techniques. Further, solubility study of this synthesized compound was conducted in methanol, ethanol, 1-propanol, 1-butanol, tetrahydrofuran (THF), ethyl acetate (EA), acetone (AC) and chloroform (CF) at temperatures ranging from (293.15 to 323.15) K under atmospheric pressure. Further, the solubility data were correlated against temperature and were found to increase with temperature. The modified Apelblat and Buchowski–Ksiazczak λh equations were used to correlate the experimental solubility data. Further, some thermodynamic parameters such as dissolution enthalpy (ΔH), Gibbs free energy (ΔG) and entropy (ΔS) of mixing have also been calculated. The positive enthalpy and Gibbs free energy values suggest the dissolution process to be endothermic and spontaneous

  17. Role of α-Helical Structure in Organic Solvent-Activated Homodimer of Elastase Strain K

    Chee Fah Wong

    2011-09-01

    Full Text Available Recombinant elastase strain K overexpressed from E. coli KRX/pCon2(3 was purified to homogeneity by a combination of hydrophobic interaction chromatography and ion exchange chromatography, with a final yield of 48% and a 25-fold increase in specific activity. The purified protein had exhibited a first ever reported homodimer size of 65 kDa by SDS-PAGE and MALDI-TOF, a size which is totally distinct from that of typically reported 33 kDa monomer from P. aeruginosa. The organic solvent stability experiment had demonstrated a stability pattern which completely opposed the rules laid out in previous reports in which activity stability and enhancement were observed in hydrophilic organic solvents such as DMSO, methanol, ethanol and 1-propanol. The high stability and enhancement of the enzyme in hydrophilic solvents were explained from the view of alteration in secondary structures. Elastinolytic activation and stability were observed in 25 and 50% of methanol, respectively, despite slight reduction in α-helical structure caused upon the addition of the solvent. Further characterization experiments had postulated great stability and enhancement of elastase strain K in broad range of temperatures, pHs, metal ions, surfactants, denaturing agents and substrate specificity, indicating its potential application in detergent formulation.

  18. Effect of water miscible organic solvents on p-nitrophenol hydroxylase (CYP2E1 activity in rat liver microsomes

    Pranali G Patil

    2015-01-01

    Full Text Available Organic solvents used for solubilization of the substrates/NCEs are known to affect the activity of cytochrome P450 enzymes. Further, this effect varies with the solvents used, the substrates and CYP450 isoforms in question. In the present study, we have investigated the effect of ten commonly used water miscible organic solvents (methanol, ethanol, 1-propanol, 2-propanol, acetonitrile, acetone, dimethyl sulphoxide, N,N-dimethyl formamide, dioxane and polyethylene glycol 400 on p-nitrophenol hydroxylase activity at 0, 0.1, 0.25, 0.5, 0.75 and 1% v/v concentration in rat liver microsomes. All the solvents studied showed concentration dependent inhibition of the p-nitrophenol hydroxylase activity except acetonitrile which showed activation of the activity at concentration range studied. Out of ten solvents studied, dioxane was found to be the most inhibitory solvent (inhibition >90% at 0.25% v/v concentration. Overall, solvents like dimethyl sulphoxide, dimethyl formamide and dioxane appeared to be unsuitable for characterizing p-nitrophenol hydroxylase (CYP2E1-mediated reactions due to a high degree of inhibition. On the other hand, methanol and acetonitrile at concentrations <0.5% v/v appeared to be appropriate solvents for substrate solubilization while evaluating CYP2E1-mediated catalysis. The results of this study imply that caution should be exercised while choosing solvents for dissolution of substrate during enzyme studies in liver microsomes.

  19. Inhibition of ceramide glucosylation sensitizes lung cancer cells to ABC294640, a first-in-class small molecule SphK2 inhibitor.

    Guan, Shuhong; Liu, Yuan Y; Yan, Tingzan; Zhou, Jun

    2016-08-01

    Sphingosine kinase 2 (SphK2) is proposed as a novel oncotarget for lung cancer. Here, we studied the anti-lung cancer cell activity by ABC294640, a first-in-class SphK2 inhibitor. We showed that ABC294640 suppressed growth of primary and A549 human lung cancer cells, but sparing SphK2-low lung epithelial cells. Inhibition of SphK2 by ABC294640 increased ceramide accumulation, but decreased pro-survival sphingosine-1-phosphate (S1P) content, leading to lung cancer cell apoptosis activation. Significantly, we show that glucosylceramide synthase (GCS) might be a major resistance factor of ABC294640. The GCS inhibitor 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) or GCS shRNA/siRNA knockdown facilitated ABC294640-induced ceramide production and lung cancer cell apoptosis. Reversely, forced overexpression of GCS reduced ABC294640's sensitivity, resulting in decreased ceramide accumulation and apoptosis induction in A549 cells. These findings provide further evidences to support that targeting SphK2 by ABC294640 may be a rational treatment option for lung cancer. Ceramide glucosylation inhibition may further sensitize lung cancer cells to ABC294640. PMID:27221045

  20. PERPINDAHAN PANAS DAN MASSA PADA PENGEMBUNAN CAMPURAN METANOL-PROPANOL-UDARA DALAM KONDENSOR TEGAK

    Sarto Sarto

    2012-02-01

    Full Text Available Pengembunan campuran uap dan gas melibatkan mekanisme perpindahan panas dan massa secara simultan yang sangat rumit sehingga pendekatan teoritis terhadap peristiwanya belum cukup untuk diterapkan pada perancangan kondensor. Penelitian ini dimaksudkan untuk memperoleh persamaan semi-empirik yang sederhana dan cukup teliti sebagai dasar memperkirakan koefisien perpindahan panas dan massa proses pengembunan campuran metanol(1-propanol(2-udara. Percobaan pengembunan dilakukan di dalam kondensor pipa ganda tegak sepanjang 1,7 m. Ukuran pipa luar dan dalam berturut-turut sebesar 50 mm dan 25 mm. Campuran uap dan gas dialirkan dari atas melalui anulus sedangkan air pendingin dialirkan di dalam pipa dari bawah sehingga sistem menjadi berlawanan arah. Data percobaan meliputi kecepatan alir dan suhu air pendingin, komposisi dan suhu campuran uap-gas, kecepatan alir dan suhu kondensat, kecepatan alir udara, dan tekanan sistem. Koefisien perpindahan panas dan massa dievaluasi melalui model matematik yang disusun berdasarkan neraca massa dan panas yang diselesaikan secara simultan. Hasil penelitian dinyatakan dalam bentuk bilangan tak berdimensi yaitu Nu=19,9297(1-yn2,9164Re0,8142Pr1/3. Adapun hubungan fungsional bilangan Sherwood yang merupakan bentuk bilangan tak berdimensi koefisien perpindahan massa dinyatakan dengan persamaan Sh1=15,1042(1-yn2,9696Re0,8068Sc1/3 dan Sh2=5,7227(1-yn2,9916Re0,8113 Sc1/3

  1. Proteinase-producing halophilic lactic acid bacteria isolated from fish sauce fermentation and their ability to produce volatile compounds.

    Udomsil, Natteewan; Rodtong, Sureelak; Tanasupawat, Somboon; Yongsawatdigul, Jirawat

    2010-07-15

    Halophilic lactic acid bacteria were isolated from fish sauce mashes fermented at 1 to 12 months. Seven out of sixty-four isolates were selected according to their proteolytic activity and growth at 25% NaCl for characterization and investigation of volatile compound production. All selected isolates were Gram-positive cocci with pairs/tetrads and grew at 0-25% NaCl, pH 4.5-9.0. Results of 16S rRNA gene sequence analysis showed 99% homology to Tetragenococcus halophilus ATCC 33315. The restriction fragment length polymorphism (RFLP) patterns of all isolates were also similar to those of T. halophilus ATCC 33315. These isolates were, thus, identified as T. halophilus. All isolates hydrolyzed fish protein in the medium containing 25% NaCl. Intracellular aminopeptidase of 7 isolates exhibited the highest activity of 2.85-3.67 U/ml toward Ala-p-nitroanilide (Ala-pNA). T.halophilus strains MS33 and M11 showed the highest alanyl aminopeptidase activity (Phalophilus MS33 and MRC5-5-2 were 1-propanol, 2-methylpropanal, and benzaldehyde, corresponding to major volatile compounds in fish sauce. T.halophilus appeared to play an important role in volatile compound formation during fish sauce fermentation. PMID:20541276

  2. Osmotic coefficients and apparent molar volumes of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid in alcohols

    Highlights: • Physical and osmotic properties of [HMim][TfO] in alcohols are reported. • Apparent molar properties and osmotic coefficients were obtained. • Apparent molar volumes were fitted using a Redlich–Meyer type equation. • The osmotic coefficients were modeled with the Extended Pitzer and the MNRTL models. -- Abstract: In this work, density for the binary mixtures of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate in alcohols (1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol) was measured at T = 323.15 K and atmospheric pressure. From this property, the corresponding apparent molar volumes were calculated and fitted to a Redlich–Meyer type equation. For these mixtures, the osmotic and activity coefficients, and vapor pressures of these binary systems were also determined at the same temperature using the vapor pressure osmometry technique. The experimental osmotic coefficients were modeled by the Extended Pitzer model of Archer. The parameters obtained in this correlation were used to calculate the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures

  3. Osmotic and apparent molar properties of binary mixtures alcohol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid

    Highlights: ► Osmotic and physical properties of binary mixtures {alcohol + [BMim][TfO]} were measured. ► From experimental data, apparent molar properties and osmotic coefficients were calculated. ► The apparent properties were fitted using a Redlich–Meyer type equation. ► The osmotic coefficients were correlated using the Extended Pitzer model. -- Abstract: In this work, physical properties (densities and speeds of sound) for the binary systems {1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate} were experimentally measured from T = (293.15 to 323.15) K and at atmospheric pressure. These data were used to calculate the apparent molar volume and apparent molar isentropic compression which were fitted to a Redlich–Meyer type equation. This fit was used to obtain the corresponding apparent molar properties at infinite dilution. On the other hand, the osmotic and activity coefficients and vapor pressures of these binary mixtures were also determined at T = 323.15 K using the vapor pressure osmometry technique. The Extended Pitzer model of Archer was employed to correlate the experimental osmotic coefficients. From the parameters obtained in the correlation, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated

  4. Alternative chromatographic system for the quality control of lipophilic technetium-99m radiopharmaceuticals such as [99mTc(MIBI)6]+

    Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [99mTc(MIBI)6]+ as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol: chloroform (25:75), Whatman 3MM paper and ethanol:chloroform (25:75), and the more expensive ITLC-SG and 1-propanol: chloroform (10:90) were suitable systems for the direct determination of radiochemical purity of [99mTc(MIBI)6]+ since impurities such as 99mTc-reduced-hydrolyzed (RH), 99mTcO4- and [99mTc(cysteine)2]- complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines. (author)

  5. Effect of the temperature on the physical properties of the pure ionic liquid 1-ethyl-3-methylimidazolium methylsulfate and characterization of its binary mixtures with alcohols

    Highlights: • Physical properties of the pure [EMim][MSO4] ionic liquid. • Physical and excess properties of its binary mixtures with alcohols. • The excess properties were fitted using the Redlich–Kister equation. • The effect of temperature on the VE, and KS,mE was analyzed. - Abstract: Experimental density, speed of sound, refractive index and viscosity data of the pure ionic liquid 1-ethyl-3-methylimidazolium methylsulfate, [EMim][MSO4], were measured as a function of temperature from T = (293.15 to 343.15) K, every 5 K, and atmospheric pressure. Density, speed of sound and refractive index data were satisfactorily correlated with a linear equation, while viscosity data were fitted to the Vogel–Fulcher–Tamman (VFT) equation. Besides, from the experimental density values, the thermal expansion coefficient, α, was calculated. Furthermore, density and speed of sound for the binary systems of {methanol, or ethanol, or 1-propanol, or 2-propanol, or 1-butanol, or 1-pentanol + [EMim][MSO4]} were experimentally determined over the whole composition range, at T = (288.15, 298.15 and 308.15) K and p = 0.1 MPa. These properties were used to calculate the corresponding excess molar volumes and excess molar isentropic compressions, which were satisfactorily fitted to the Redlich–Kister equation. Finally, a comparison with available literature data was also carried out and the obtained results are discussed in terms of interactions and structure factors in these binary mixtures

  6. Determination and modelling of osmotic coefficients and vapour pressures of binary systems 1- and 2-propanol with CnMimNTf2 ionic liquids (n = 2, 3, and 4) at T = 323.15 K

    Highlights: → Osmotic coefficients of 1- and 2-propanol with CnMimNTf2 (n = 2, 3, and 4) are determined. → Experimental data were correlated with extended Pitzer model of Archer and MNRTL. → Mean molal activity coefficients and excess Gibbs free energies were calculated. → Effect of the anion is studied comparing these results with literature. - Abstract: The osmotic and activity coefficients and vapour pressures of binary mixtures containing 1-propanol, or 2-propanol and imidazolium-based ionic liquids with bis(trifluoromethylsulfonyl)imide as anion (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C2MimNTf2, 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, C3MimNTf2, and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, C4MimNTf2) were determined at T = 323.15 K using the vapour pressure osmometry technique. The experimental osmotic coefficients were correlated using the extended Pitzer model modified by Archer and the MNRTL model, obtaining standard deviations lower than 0.033 and 0.064, respectively. The mean molal activity coefficients and the excess Gibbs free energy for the mixtures studied were calculated from the parameters of the extended Pitzer model modified by Archer. Besides the effect of the alkyl-chain of the cation, the effect of the anion can be assessed comparing the experimental results with those previously obtained for imidazolium ionic liquids with sulphate anions.

  7. Is there any sense to investigate volumetric and acoustic properties of more binary mixtures containing Ionic Liquids?

    Highlights: • Calculations of excess quantities of binary mixtures of IL + molecular solvent. • Analysis of excess properties for mixtures in order to find some regularities. • Balankina’s functions as tool to systematize excesses of IL + solvent mixtures. • Discussion of calculated absolute and relative excesses. • Prediction of absolute and relative excesses for similar binary systems. - Abstract: The excess speed of sound, excess molar volume and excess molar isentropic compressibility of 52 binary mixtures containing Ionic Liquids at T = 298.15 K were calculated using selected literature speed of sound and density data. The second components were alcohols: methanol, or ethanol, or 1-propanol, or 2-propanol, or 1-butanol or other solvents: acetone, acetonitrile, tetrahydrofuran, dichloromethane and dimethylsulfoxide. The Balankina’s relative excesses, Xbal, i.e. the ratios between excess and ideal quantities XE/Xid were also determined to reduce the structural impact of pure components to absolute excesses. Analysis of quantities determined shows some patterns for concentration dependences of large groups of mixtures; thus, the scheme for influence of anion or cation of Ionic Liquids and solvent on Balankina’s relative excesses was proposed. It seems that presented analysis provide the knowledge about absolute and relative excess quantities for other mixtures without doing the experimental work. It is also visible that analysis of excess molar quantities and Xbal parameters can support the interpretation of interactions which occur between Ionic Liquids and solvent

  8. Osmotic coefficients of alcoholic mixtures containing BMpyrDCA: Experimental determination and correlation

    Graphical abstract: - Highlights: • Osmotic coefficients of alcohols with BMpyrDCA ionic liquid are determined. • Experimental data were correlated with Extended Pitzer model of Archer and MNRTL. • Mean molal activity coefficients and excess Gibbs free energies were calculated. • The results have been interpreted in terms of interactions. - Abstract: The vapour pressure osmometry technique (VPO) has been used to obtain the osmotic coefficients of the binary mixtures of the primary and secondary alcohols 1-propanol, 2-propanol, 1-butanol, 2-butanol and 1-pentanol with the ionic liquid 1-butyl-1-methylpyrrolidinium dicyanamide, BMpyrDCA. From these coefficients, the corresponding activity coefficients and vapour pressures of the mixtures have been also determined. The results have been discussed in terms of solute–solvent and ion–ion interactions and have been compared with those taken from literature in order to analyse the influence of the anion or cation constituting the ionic liquid. For the treatment of the experimental data, the Extended Pitzer model of Archer and the MNRTL model have been applied, obtaining standard deviations from the experimental osmotic coefficients lower than 0.015 and 0.065, respectively. From the parameters obtained with the Extended Pitzer model or Archer, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures have been calculated

  9. Vapour pressures and osmotic coefficients of binary mixtures containing alcohol and pyrrolidinium-based ionic liquids

    Highlights: • Osmotic coefficients of alcohols with pyrrolidinium ILs are determined. • Experimental data were correlated with extended Pitzer model of Archer and MNRTL. • Mean molal activity coefficients and excess Gibbs free energies were calculated. • The results have been interpreted in terms of interactions. -- Abstract: The osmotic and activity coefficients and vapour pressures of mixtures containing primary (1-propanol, 1-butanol and 1-pentanol) and secondary (2-propanol and 2-butanol) alcohols with pyrrolidinium-based ionic liquids (1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide, C4MpyrNTf2, and 1-butyl-1-methyl pyrrolidinium trifluoromethanesulfonate, C4MpyrTFO) have been experimentally determined at T = 323.15 K. For the experimental measurements, the vapour pressure osmometry technique has been used. The results on the influence of the structure of the alcohol and of the anion of the ionic liquid on the determined properties have been discussed and compared with literature data. For the correlation of the osmotic coefficients obtained, the Extended Pitzer model of Archer and the Modified Non-Random Two Liquids model were applied. The mean molal activity coefficients and the excess Gibbs energy for the studied mixtures were calculated from the parameters obtained in the correlation

  10. Correlation of Chemical and Physical Test Data for the Environmental Ageing of Tefzel (ETFE). Revised

    Morgan, G. J.; Campion, R. P.

    1997-01-01

    In a similar approach to that used for the previously issued correlation report for Coflon (CAPP/M.10), this report aims to identify any correlations between mechanical property changes and chemical/morphological changes for Tefzel, using information supplied in other MERL and TRI project reports. Differences identified with Coflon behaviour will be of scientific interest as well as appropriate to project applications, as Tefzel and Coflon are chemical isomers. Owing to the considerable chemical resistance of Tefzel, much of its testing so far has been based on mechanical properties. Where changes have occurred, chemical analysis can now be targeted more effectively. Relevant test data collated here include: tensile modulus and related properties, permeation coefficients, % crystallinity, some crack growth resistance measurements, and other observations where significant. Fluids based on methanol and amine (Fluid G), a mixture of methane, carbon dioxide and hydrogen sulphide gases plus an aqueous amine solution (Fluid F), and an aromatic oil mix of heptane, cyclohexane, toluene and 1-propanol (Fluid I) have affected Tefzel to varying degrees, and are discussed in some detail herein.

  11. Accelerated solvent extraction of alkylresorcinols in food products containing uncooked and cooked wheat.

    Holt, Monte D; Moreau, Robert A; DerMarderosian, Ara; McKeown, Nicola; Jacques, Paul F

    2012-05-16

    This research focuses on the overall extraction process of alkylresorcinols (ARs) from uncooked grains and baked products that have been processed with wheat, corn, rice, and white flour. Previously established extraction methods developed by Ross and colleagues, as well as a semiautomated method involving accelerated solvent extraction (ASE), were applied to extract ARs within freshly ground samples. For extraction of alkylresorcinols, nonpolar solvents such as ethyl acetate have been recommended for the extraction of uncooked foods, and polar solvents such as 1-propanol:water (3:1 v/v) have been recommended for the extraction of baked foods that contain rye, wheat, or other starch-rich grains. A comparison of AR extraction methods has been investigated with the application of gas chromatography and a flame ionization detector (GC-FID) to quantify the AR content. The goal of this research was to compare the rapid accelerated solvent extraction of the alkylresorcinols (ASE-AR) method to the previous manual AR extraction methods. Results for this study as well as the investigation of the overall efficiency of ASE-AR extraction with the use of a spiking study indicated that it can be comparable to current extraction methods but with less time required. Furthermore, the extraction time for ASE (approximately 40 min) is much more convenient and less tedious and time-consuming than previously established methods, which range from 5 h for processed foods to 24 h for raw grains. PMID:22530555

  12. Effect of acid catalysts and accelerated aging on the reaction of methanol with hydroxy-acetaldehyde in bio-oil

    Bhattacharya, P.

    2010-05-01

    Full Text Available Bio-oil is a promising alternative source of energy produced from fast pyrolysis of biomass. Increasing the viscosity of bio-oil during storage is a major problem that can be controlled by the addition of methanol or other alcohols. This paper reports the results of our investigation of the reactions of short chain alcohols with aldehydes and acids in bio-oil. The reaction of methanol with hydroxyacetaldehyde (HA to form the acetal was catalyzed by the addition of 7 x 10-4 M strong acids such as sulfuric, hydrochloric, p-toluene sulfonic acid, and methanesulfonic acid. HA formed 2,2-dimethoxyethanol (DME, and at 60 oC the equilibrium was reached in less than one hour. Smaller amounts of DME were formed in the absence of strong acid. HA, acetaldehyde, and propanal formed their corresponding acetals when reacted with methanol, ethanol, 1-propanol or 1-butanol. Esters of acetic acid and hydroxyacetic acid were observed from reactions with these same four alcohols. Other acetals and esters were observed by GC/MS analysis of the reaction products. The results from accelerated aging experiments at 90 oC suggest that the presence of methanol slows polymerization by formation of acetals and esters from low molecular weight aldehydes and organic acids.

  13. Analysis of methanol and ethanol in virgin olive oil

    Gómez-Coca, Raquel B.; Cruz-Hidalgo, Rosario; Fernandes, Gabriel D.; Pérez-Camino, María del Carmen; Moreda, Wenceslao

    2014-01-01

    This work provides a short and easy protocol that allows the analysis of both methanol and ethanol in the static headspace of olive oil. The procedure avoids any kind of sample pre-treatment beyond that of heating the oil to allow a maximum volatile concentration in the headspace of the vials. The method's LOD is 0.55 mg kg−1 and its LOQ is 0.59 mg kg−1. Advantages of this method are:•Simultaneous determination of methanol and ethanol (the pre-existing Spanish specification UNE-EN 14110 only analyses methanol).•No need of equipment modifications (standard split injectors work perfectly). Use of a highly polar capillary GC column, leading in most cases to chromatograms in which only three dominant peaks are present – methanol, ethanol, and propanol (that is extremely positive for easy interpretation of results).•Use of an internal standard (1-propanol) to determine the concentration of the analytes, reducing the presence of error sources. PMID:26150954

  14. Heterometallic Cu(II)-Dy(III) Clusters of Different Nuclearities with Slow Magnetic Relaxation.

    Modak, Ritwik; Sikdar, Yeasin; Cosquer, Goulven; Chatterjee, Sudipta; Yamashita, Masahiro; Goswami, Sanchita

    2016-01-19

    The synthesis, structures, and magnetic properties of two heterometallic Cu(II)-Dy(III) clusters are reported. The first structural motif displays a pentanuclear Cu(II)4Dy(III) core, while the second one reveals a nonanuclear Cu(II)6Dy(III)3 core. We employed o-vanillin-based Schiff base ligands combining o-vanillin with 3-amino-1-propanol, H2vap, (2-[(3-hydroxy-propylimino)-methyl]-6-methoxy-phenol), and 2-aminoethanol, H2vae, (2-[(3-hydroxy-ethylimino)-methyl]-6-methoxy-phenol). The differing nuclearities of the two clusters stem from the choice of imino alcohol arm in the Schiff bases, H2vap and H2vae. This work is aimed at broadening the diversity of Cu(II)-Dy(III) clusters and to perceive the consequence of changing the length of the alcohol arm on the nuclearity of the cluster, providing valuable insight into promising future synthetic directions. The underlying topological entity of the pentanuclear Cu4Dy cluster is reported for the first time. The investigation of magnetic behaviors of 1 and 2 below 2 K reveals slow magnetic relaxation with a significant influence coming from the variation of the alcohol arm affecting the nature of magnetic interactions. PMID:26702645

  15. Use of micellar liquid chromatography to analyze oxolinic acid, flumequine, marbofloxacin and enrofloxacin in honey and validation according to the 2002/657/EC decision.

    Tayeb-Cherif, K; Peris-Vicente, J; Carda-Broch, S; Esteve-Romero, J

    2016-07-01

    A micellar liquid chromatographic method was developed for the analysis of oxolinic acid, flumequine, marbofloxacin and enrofloxacin in honey. These quinolines are unethically used in beekeeping, and a zero-tolerance policy to antibiotic residues in honey has been stated by the European Union. The sample pretreatment was a 1:1 dilution with a 0.05M SDS at pH 3 solution, filtration and direct injection, thus avoiding extraction steps. The quinolones were eluted without interferences using mobile phase of 0.05M SDS/12.5% 1-propanol/0.5% triethylamine at pH 3, running at 1mL/min under isocratic room through a C18 column. The analytes were detected by fluorescence. The method was successfully validated according to the requirements of the European Union Decision 2002/657/EC in terms of: specificity, linearity (r(2)>0.995), limit of detection and decision limit (0.008-0.070mg/kg), lower limit of quantification (0.02-0.2mg/kg), detection capability (0.010-0.10mg/kg), recovery (82.1-110.0%), precision (effects, robustness (honey supplied by a local supermarket, and the studied antibiotics were not detected. Therefore, the method was rapid, simple, safe, eco friendly, reliable and useful for the routine analysis of honey samples. PMID:26920300

  16. Temperature dependence studies on the electro-oxidation of aliphatic alcohols with modified platinum electrodes

    Panadda Katikawong; Tanakorn Ratana; Waret Veerasai

    2009-05-01

    Temperature dependence on the electro-oxidation of methanol, ethanol and 1-propanol in 0.5 M H2SO4 were investigated with Pt and PtRu electrodes. Tafel slope and apparent activation energy were evaluated from the cyclic voltammetric data in the low potential region (0.3-0.5 V vs SHE). The CV results provided Tafel slopes for alcohols in the range of 200-400 mV dec-1 which indicated a difference in the rate determining step. The decrease in Tafel slope was only observed in the case of methanol for the Ru-modified Pt electrode. This indicates that Ru improves the rate of determining step for methanol while hindering it for the other alcohols. The electrochemical impedance spectroscopy was also used to evaluate the electro-oxidation mechanism of alcohols on these electrodes. The simulated EIS results provided two important parameters: charge transfer resistance () and inductance (). The $R^{-1}_{ct}$ and -1 represent the rate of alcohol electro-oxidation and rate of desorption of intermediate species, respectively. These values increased with the increasing of temperature. The results from two techniques were well agreed that the electro-oxidation of methanol was improved by raising the temperature and ruthenium modification.

  17. Identification of the degradation pathways of alkanolamines with TiO{sub 2} photocatalysis

    Lu, Chung-Shin, E-mail: cslu6@ntcnc.edu.tw [Department of General Education, National Taichung Nursing College, Taichung 403, Taiwan (China); Chen, Chiing-Chang [Department of Science Application and Dissemination, National Taichung University, Taichung 403, Taiwan (China); Mai, Fu-Der [Department of Biochemistry, School of Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Li, Hua-Kuang [Department of General Education, National Taichung Nursing College, Taichung 403, Taiwan (China)

    2009-06-15

    The present study deals with the photocatalytic degradation of the alkanolamine, 2-dimethylamino-2-methyl-1-propanol (DMAMP), in the presence of TiO{sub 2} particles and UV-A ({lambda} = 365 nm) radiation. The obtained results show complete oxidation of DMAMP after 20 h, and a little over 90% of DMAMP was mineralization after 64-h of treatment. The effects of the solution pH, catalyst loading, and anions on the photocatalytic degradation of DMAMP were investigated, as well as the reaction intermediates that were formed during treatment. To the best of our knowledge, this is the first time that reports the degradation pathways of DMAMP. A number of intermediates were identified by GC/MS techniques during the treatment of DMAMP, following three tentative degradation routes. The first one is based on the oxidation of the primary alcohol group leading to the formation of corresponding aldehyde and carboxylic acid. The second route is based on the rupture of the N-C bond to form 2-methylpropanal and acetone. The last degradation route is based on the cyclization of the {beta}-amino alcohol group to form the oxazolidine derivatives.

  18. Identification of the degradation pathways of alkanolamines with TiO2 photocatalysis

    The present study deals with the photocatalytic degradation of the alkanolamine, 2-dimethylamino-2-methyl-1-propanol (DMAMP), in the presence of TiO2 particles and UV-A (λ = 365 nm) radiation. The obtained results show complete oxidation of DMAMP after 20 h, and a little over 90% of DMAMP was mineralization after 64-h of treatment. The effects of the solution pH, catalyst loading, and anions on the photocatalytic degradation of DMAMP were investigated, as well as the reaction intermediates that were formed during treatment. To the best of our knowledge, this is the first time that reports the degradation pathways of DMAMP. A number of intermediates were identified by GC/MS techniques during the treatment of DMAMP, following three tentative degradation routes. The first one is based on the oxidation of the primary alcohol group leading to the formation of corresponding aldehyde and carboxylic acid. The second route is based on the rupture of the N-C bond to form 2-methylpropanal and acetone. The last degradation route is based on the cyclization of the β-amino alcohol group to form the oxazolidine derivatives.

  19. The Search for a Volatile Human Specific Marker in the Decomposition Process.

    E Rosier

    Full Text Available In this study, a validated method using a thermal desorber combined with a gas chromatograph coupled to mass spectrometry was used to identify the volatile organic compounds released during decomposition of 6 human and 26 animal remains in a laboratory environment during a period of 6 months. 452 compounds were identified. Among them a human specific marker was sought using principle component analysis. We found a combination of 8 compounds (ethyl propionate, propyl propionate, propyl butyrate, ethyl pentanoate, pyridine, diethyl disulfide, methyl(methylthioethyl disulfide and 3-methylthio-1-propanol that led to the distinction of human and pig remains from other animal remains. Furthermore, it was possible to separate the pig remains from human remains based on 5 esters (3-methylbutyl pentanoate, 3-methylbutyl 3-methylbutyrate, 3-methylbutyl 2-methylbutyrate, butyl pentanoate and propyl hexanoate. Further research in the field with full bodies has to corroborate these results and search for one or more human specific markers. These markers would allow a more efficiently training of cadaver dogs or portable detection devices could be developed.

  20. Oleic acid based heterolipid synthesis, characterization and application in self-microemulsifying drug delivery system.

    Kalhapure, Rahul S; Akamanchi, Krishnacharya G

    2012-04-01

    There is increasing demand for lipids owing to their use in formulating lipid based drug delivery systems of poorly soluble drugs. The present work discusses the synthesis, characterization of oleic acid based heterolipid and its use as oil in the development of self-microemulsifying drug delivery system (SMEDDS) for parenteral delivery. Synthesis was carried out by Michael addition of tert-butyl acrylate to 3-amino-1-propanol to obtain di-tert-butyl aminopropanol derivative. Reaction of this di-tert-butyl aminopropanol derivative with oleoyl chloride using p-dimethylaminopyridine as a coupling agent gave the desired heterolipid. It was characterized by (1)H NMR, (13)C NMR and MS to confirm the structure. It did not exhibit any measurable cytotoxicity, even up to 80μg/ml concentration. Application in parenteral drug delivery was explored using furosemide (FUR), a BCS class IV drug, as a model. FUR showed three times greater solubility in the heterolipid as compared to oleic acid. SMEDDSs were developed using heterolipid as oily phase, Solutol HS 15(®) as surfactant and ethanol as a co-surfactant. Developed SMEDDS could form spontaneous microemulsion on addition to various aqueous phases with mean globule size <70nm without any phase separation or drug precipitation even after 24h, and exhibited negligible hemolytic potential. PMID:22266534

  1. Protonation thermodynamics of some aminophenol derivatives in NaCl{sub (aq)} (0 {<=} I {<=}3 mol . kg{sup -1}) at T = 298.15 K

    Bretti, Clemente; De Stefano, Concetta; Foti, Claudia [Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Universita di Messina, Viale F. Stagno d' Alcontres, 31, I-98166 Messina (Vill. S. Agata) (Italy); Sammartano, Silvio, E-mail: ssammartano@unime.it [Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Universita di Messina, Viale F. Stagno d' Alcontres, 31, I-98166 Messina (Vill. S. Agata) (Italy); Vianelli, Giuseppina [Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Universita di Messina, Viale F. Stagno d' Alcontres, 31, I-98166 Messina (Vill. S. Agata) (Italy)

    2012-01-15

    Highlights: > Protonation thermodynamics of four aminophenol derivatives were determined. > Dependence on ionic strength was analysed by using different models. > Neutral species activity coefficient was determined by distribution measurements. > Acid-base behaviour of this ligand class was modelled. - Abstract: The acid-base properties of four aminophenol derivatives, namely m-aminophenol (L1), 4-amino-2-hydroxytoluene (L2), 2-amino-5-ethylphenol (L3) and 5-amino-4-chloro-o-cresol (L4), are studied by potentiometric and titration calorimetric measurements in NaCl{sub (aq)} (0 {<=} I {<=} 3 mol . kg{sup -1}) at T = 298.15 K. The dependence of the protonation constants on ionic strength is modelled by the Debye-Hueckel, SIT (Specific ion Interaction Theory) and Pitzer equations. Therefore, the values of protonation constants at infinite dilution and the relative interaction coefficients are calculated. The dependence of protonation enthalpies on ionic strength is also determined. Distribution (2-methyl-1-propanol/aqueous solution) measurements allowed us to determine the Setschenow coefficients and the activity coefficients of neutral species. Experimental results show that these compounds behave in a very similar way, and common class parameters are reported, in particular for the dependence on ionic strength of both protonation constants and protonation enthalpies.

  2. Degradation of carbofuran in water by solar photocatalysis in presence of photosensitizers.

    Kuo, W S; Chiang, Y H; Lai, L S

    2006-01-01

    The effect of the presence of photosensitizers, methylene blue (MB) and rose Bengal (RB), on the degradation of carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) in water in a solar photocatalytic system was investigated. It was found that as compared to MB, RB generally showed a stronger effect on the decomposition of carbofuran under comparable conditions. Among the conditions studied, adding 2 x 10(-6) M of RB, that corresponding to 2% of the initial concentration of carbofuran solution in the system, rendered the most effective degradation of carbofuran. As a result, a carbofuran removal percentage of 69.9%, a mineralization efficiency of 28.0%, and a microtoxicity reduction of 65.0% could be achieved. The degradation and mineralization of carbofuran was found to follow the pseudo-first order reaction kinetics. The decomposition mechanism of carbofuran was further investigated through identification of the intermediates to elaborate the influence of dye photosensitizer on the solar photocatalysis of carbofuran in water. On the basis of the intermediates identified, including carbofuran phenol, 3-hydroxy carbofuran phenol, and substituted alcohols (3-phenoxy 1-propanol, 2-ethyl 1-hexanol, 2-butoxyl ethanol), it appears that hydrolysis and hydroxylation were the two key mechanisms for decomposing carbofuran during the process of solar photocatalysis with the aid of dye photosensitizer. PMID:16893781

  3. Solvent sorting in (mixed solvent + electrolyte) systems: Time-resolved fluorescence measurements and theory

    Harun Al Rasidgazi; Hemant K Kashyap; Ranjit Biswas

    2015-01-01

    In this manuscriptwe explore electrolyte-induced modification of preferential solvation of a dipolar solute dissolved in a binary mixture of polar solvents. Composition dependence of solvation characteristics at a fixed electrolyte concentration has been followed. Binary mixtures of two different polarities have been employed to understand the competition between solute-ion and solute-solvent interactions. Time-resolved fluorescence Stokes shift and anisotropy have been measured for coumarin 153 (C153) in moderately polar (ethyl acetate + 1-propanol) and strongly polar (acetonitrile + propylene carbonate) binary mixtures at various mixture compositions, and in the corresponding 1.0M solutions of LiClO4. Both the mixtures show red shifts in C153 absorption and fluorescence emission upon increase of mole fraction of the less polar solvent component in presence of the electrolyte. In addition, measured average solvation times become slower and rotation times faster for the above change in the mixture composition. A semi-molecular theory based on solution density fluctuations has been developed and found to successfully capture the essential features of the measured Stokes shift dynamics of these complex multi-component mixtures. Dynamic anisotropy results have been analyzed by using both Stokes-Einstein-Debye (SED) and Dote-Kivelson-Schwartz (DKS) theories. The importance of local solvent structure around the dissolved solute has been stressed.

  4. Separation of Purine and Its Derivatives by Capillary Zone Electrophoresis

    ZengBai-zhao; ZhaoFa-qiong

    2003-01-01

    The separation of a group of 17 purine and its derivatives by capillary zone electrophoresis is presented. A systematic approach was used to study the effect of pH, buffer type, organic modifiers, applied potential, sodium dodecyl sulfate (SDS) and cyclodextrins on the separation of these purine derivatives. An ideal condition was found for their separation, which was 30 mmol/L sodium borate buffer (pH 9-9.5), 10% (V/V) methanol buffer modifier and 20 kV. Under this condition, the 17 purine derivatives were baseline separated and the linear correlation coefficient for adenine,uric acid and 2-thioxanthine was 0. 99 over two orders of magnitude. The variation of peak areas was less than 4.6%(n= 5) and that of migration times was in the range of 0%-3%, while the samples were injected hydrodynamically at a height of 15 cm and an injection time of 8-10 s. In addition,alcohol, 1-propanol, 1-butanol and acetonitrile were also effective additives in the separation. However, SDS and various β-cyclodextrin (β-CDs) were found to do no good to their separation.

  5. Separation of Purine and Its Derivatives by Capillary Zone Electrophoresis

    Zeng Bai-zhao; Zhao Fa-qiong

    2003-01-01

    The separation of a group of 17 purine and its derivatives by capillary zone electrophoresis is presented. A systematic approach was used to study the effect of pH, buff-er type, organic modifiers, applied potential, sodium dodecyl sulfate (SDS) and cyclodextrins on the separation of these pu-rine derivatives. An ideal condition was found for their se-paration, which was 30 mmol/L sodium borate buffer (pH 9-9.5), 10% (V/V) methanol buffer modifier and 20 kV. Un-der this condition, the 17 purine derivatives were baseline separated and the linear correlation coefficient for adenine,uric acid and 2-thioxanthine was 0. 99 over two orders of magnitude. The variation of peak areas was less than 4.6 %(n=5) and that of migration times was in the range of 0%-3%, while the samples were injected hydrodynamically at a height of 15 cm and an injection time of 8-10 s. In addition,alcohol, 1-propanol, 1-butanol and acetonitrile were also ef-fective additives in the separation. However, SDS and various β-cyclodextrin (β-CDs) were found to do no good to their se-paration.

  6. A capillary electrophoretic system based on a novel microemulsion for the analysis of coenzyme Q10 in human plasma by electrokinetic chromatography.

    Lucangioli, Silvia; Flor, Sabrina; Sabrina, Flor; Contin, Mario; Mario, Contin; Tripodi, Valeria; Valeria, Tripodi

    2009-06-01

    A new analytical method for determination of coenzyme Q10 (2,3-dimethoxy-5-methyl-6-decaprenyl-1,4-benzoquinone, CoQ10) in human plasma was developed based on CE using a double tensioactive microemulsion. CoQ10 was quantitatively extracted into 1-propanol/hexane and quantified by MEEKC. The microemulsion was prepared by mixing 1.4% w/w sodium bis(2-ethylhexyl) sulfosuccinate, 4% w/w cholic acid, 1% w/w octane, 8.5% w/w butanol, 0.1% w/w PVA and 85% w/w 10 mM Tris buffer at pH 9.0. The optimized electrophoretic conditions included the use of an uncoated silica capillary of 60 cm total length and 75 mum id, an applied voltage of 20 kV, room temperature and 214 nm ultraviolet detection. Selectivity, linearity, LOD, LOQ, precision and accuracy were evaluated as the parameters of validation. Owing to its simplicity and reliability, the proposed method can be an advantageous alternative to the traditional methodology for the quantitation of CoQ10 in human plasma with good accuracy and precision. PMID:19517432

  7. Plasma-polymerized films providing selective affinity to the polarity of vaporized organic solvents

    Plasma-polymerized films (PPFs) were fabricated as recognition membranes for a vapor-sensing device, and their affinity to vaporized organic solvents was evaluated with surface plasmon resonance. The affinity we intended to create is the selective sorption of the vaporized organic solvents depending on their polarity. For this purpose, acetonitrile, ethylenediamine (EDA), styrene, hexamethyldisiloxane (HMDSO), and hexamethyldisilazane were used to fabricate PPFs. Vaporized methanol, ethanol, and 1-propanol were used as high-polar solvents to be analyzed. Hexane, toluene, and p-xylene were used as low-polar solvents. As a result, the HMDSO-PPF with 97.3o of contact angle was found to provide affinity to the low-polar solvents. In contrast, the EDA-PPF with 7.1o of contact angle provided affinity to the high-polar solvents. Observations of the surface morphology of the HMDSO- and EDA-PPFs with a scanning electron microscope revealed that they are composed of nano-scale islands.

  8. Magic number effect on cluster formation of polyhydroxylated fullerenes in water-alcohol binary solution

    Nakamura, Yuji; Ueno, Hiroshi; Kokubo, Ken, E-mail: kokubo@chem.eng.osaka-u.ac.jp; Ikuma, Naohiko; Oshima, Takumi [Osaka University, Division of Applied Chemistry, Graduate School of Engineering (Japan)

    2013-06-15

    Due to the spherical shape with a diameter of ca. 1 nm, the aggregation behaviour of fullerene C{sub 60} is very interesting in view of the possible formation of magic number particle in a similar manner as metal cluster in gas phase. Herein, we report for the first time the magic number aggregation behaviours of polyhydroxylated fullerenol C{sub 60}(OH){sub 36} in water-alcohol (methanol, ethanol and 1-propanol) binary solution with increasing alcohol component. The diameters of particle were ca. 6-8 nm depending on the alcohol used. The particle sizes were precisely measured by the novel-induced grating method which is superior for the particle-size measurement in single-nano region (1-10 nm). The magic number cluster was also detected by scanning probe microscopy observation. However, such aggregation behaviours were not found in DMSO-alcohol system or for the use of less hydroxylated C{sub 60}(OH){sub 10}.

  9. Evaluation of glycidyl methacrylate-based monolith functionalized with weak anion exchange moiety inside 0.5 mm i.d. column for liquid chromatographic separation of DNA

    Aprilia Nur Tasfiyati

    2016-03-01

    Full Text Available In this study, the organic polymer monolith was developed as a weak anion exchanger column in high performance liquid chromatography for DNA separation. Methacrylate-based monolithic column was prepared in microbore silicosteel column (100 × 0.5 mm i.d. by in-situ polymerization reaction using glycidyl methacrylate as monomer; ethylene dimethacrylate as crosslinker; 1-propanol, 1,4-butanediol, and water as porogenic solvents, with the presence of initiator α,α′-azobisisobutyronitrile (AIBN. The monolith matrix was modified with diethylamine to create weak anion exchanger via ring opening reaction of epoxy groups. The morphology of the monolithic column was studied by SEM. The properties of the monolithic column, such as permeability, mechanical stability, binding capacity and pore size distribution, were characterized in detail. From the results of the characterization, monoliths poly-(GMA-co-EDMA with total monomer percentage (%T 40 and crosslinker percentage (%C 25 was found to be the ideal composition of monomer and crosslinker. It has good mechanical stability and high permeability, adequate molecular recognition sites (represented with binding capacity value of 36 mg ml−1, and has relatively equal proportion of flow-through pore and mesopores (37.2% and 41.1% respectively. Poly-(GMA-co-EDMA with %T 40 and %C 25 can successfully separate oligo(dT12–18 and 50 bp DNA ladder with good resolution.

  10. Fluorescent-protein stabilization and high-resolution imaging of cleared, intact mouse brains.

    Martin K Schwarz

    Full Text Available In order to observe and quantify long-range neuronal connections in intact mouse brain by light microscopy, it is first necessary to clear the brain, thus suppressing refractive-index variations. Here we describe a method that clears the brain and preserves the signal from proteinaceous fluorophores using a pH-adjusted non-aqueous index-matching medium. Successful clearing is enabled through the use of either 1-propanol or tert-butanol during dehydration whilst maintaining a basic pH. We show that high-resolution fluorescence imaging of entire, structurally intact juvenile and adult mouse brains is possible at subcellular resolution, even following many months in clearing solution. We also show that axonal long-range projections that are EGFP-labelled by modified Rabies virus can be imaged throughout the brain using a purpose-built light-sheet fluorescence microscope. To demonstrate the viability of the technique, we determined a detailed map of the monosynaptic projections onto a target cell population in the lateral entorhinal cortex. This example demonstrates that our method permits the quantification of whole-brain connectivity patterns at the subcellular level in the uncut brain.

  11. Photoisomerization mechanism of 1,1'-dimethyl-2,2'-pyridocyanine in the gas phase and in solution.

    Gao, Aihua; Zhang, Peiyu; Zhao, Meiyu; Liu, Jianyong

    2015-02-01

    The trans→cis and cis→trans photoisomerization mechanisms of 1,1'-dimethyl-2,2'-pyridocyanine have been investigated theoretically in the gas phase and in methanol. Two-dimensional potential energy surfaces were computed for the ground and first excited singlet states of the isolated molecule using complete active space self-consistent field method. Our computations suggest that the torsion around the central C-C bonds with carbon-out-of-plane motion is the preferred photoisomerization mechanism. In the gas phase, conical intersections were found near the minima of excited state. The excited-state decay follows a barrierless minimum-energy pathway before the molecule moves to the excited-state global minimum (minS1) and the system relaxes to the ground state through a conical intersection. In methanol, the system would first reach a stationary structure of C2 symmetry after the trans form is electronically excited. Solvent polarity effects were investigated in chloroform, dichloromethane, 1-propanol, ethanol, methanol, and water. There is a significant barrier between the stationary structure of C2 symmetry and minS1 in the excited state in high polarity solvents. Thus, Me-1122P has a much longer lifetime of the excited state in solvents of high polarity. PMID:25456657

  12. Photoisomerization mechanism of 1,1‧-dimethyl-2,2‧-pyridocyanine in the gas phase and in solution

    Gao, Aihua; Zhang, Peiyu; Zhao, Meiyu; Liu, Jianyong

    2015-02-01

    The trans→cis and cis→trans photoisomerization mechanisms of 1,1‧-dimethyl-2,2‧-pyridocyanine have been investigated theoretically in the gas phase and in methanol. Two-dimensional potential energy surfaces were computed for the ground and first excited singlet states of the isolated molecule using complete active space self-consistent field method. Our computations suggest that the torsion around the central Csbnd C bonds with carbon-out-of-plane motion is the preferred photoisomerization mechanism. In the gas phase, conical intersections were found near the minima of excited state. The excited-state decay follows a barrierless minimum-energy pathway before the molecule moves to the excited-state global minimum (minS1) and the system relaxes to the ground state through a conical intersection. In methanol, the system would first reach a stationary structure of C2 symmetry after the trans form is electronically excited. Solvent polarity effects were investigated in chloroform, dichloromethane, 1-propanol, ethanol, methanol, and water. There is a significant barrier between the stationary structure of C2 symmetry and minS1 in the excited state in high polarity solvents. Thus, Me-1122P has a much longer lifetime of the excited state in solvents of high polarity.

  13. Increased Electrochemical Oxidation Rate of Alcohols in Alkaline Media on Palladium Surfaces Electrochemically Modified by Antimony, Lead, and Tin

    Several adatoms (M = Sb, Sn, or Pb) were added to Pd nanoparticles and examined for the electrochemical oxidation of ethanol, 1-propanol, 2-propanol, ethylene glycol, propylene glycol, and glycerol. We observed a significant increase in oxidation rate on Pd-M for each of the adatoms in each of the fuels. For example, the oxidation rate of ethanol was 1.5 times greater on Pd-Pb and Pd-Sn as compared with the oxidation rate on Pd after 10 minutes of oxidation. However, even more notable is the behavior observed by the polyhydric alcohols that exhibit sluggish reaction kinetics even in alkaline media. For example, the oxidation rate of propylene glycol on Pd-Pb was observed to be 21 times greater than the oxidation rate on Pd after 10 minutes, and it was still 7.1 times greater after 12 hours. These results show particular promise for the potential of efficiently oxidizing bulkier and higher energy density alcohols in the alkaline direct liquid fuel cell. All three bimetallic surfaces induced an increase in oxidation rate with all alcohols as compared to the monometallic Pd. Based on analysis of our results, we attribute a significant amount of the increase in oxidation rate to the bifunctional effect and suggest a lesser role is played by the electronic effect

  14. Determination of alcohol compounds using corona discharge ion mobility spectrometry

    HAN Hai-yan; HUANG Guo-dong; JIN Shun-ping; ZHENG Pei-chao; XU Guo-hua; LI Jian-quan; WANG Hong-mei; CHU Yan-nan

    2007-01-01

    Ion mobility spectrometry (IMS) is a very fast, highly sensitive, and inexpensive technique, it permits efficient monitoring of volatile organic compounds like alcohols. In this article, positive ion mobility spectra for six alcohol organic compounds have been systematically studied for the first time using a high-resolution IMS apparatus equipped with a discharge ionization source. Utilizing protonated water cluster ions (H2O)nH+ as the reactant ions and clean air as the drift gas, alcohol organic compounds, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-pentanol and 2-octanol, all exhibit product ion characteristic peaks in their respective ion mobility spectrometry, that is a result of proton transfer reactions between the alcohols and reaction ions (H2O)nH+. The mixture of these alcohols, including two isomers, has been detected, and the result shows that they can also be distinguished effectively in the ion mobility spectrum. The reduced mobility values have been determined, which are in very well agreement with the traditional 63Ni-IMS experimental values. The exponential dilution method was used to calibrate the alcohol concentrations, and a detection limit available for the alcohols is in order of magnitude of a few ng/L.

  15. Experimental Measurement and Thermodynamic Modeling of the Solubility of Carbon Dioxide in Aqueous Alkanolamine Solutions in the High Gas Loading Region

    Suleman, Humbul; Maulud, Abdulhalim Shah; Man, Zakaria

    2016-09-01

    The solubility of carbon dioxide in aqueous alkanolamine solutions was investigated in the high gas loading region based on experimental measurements and thermodynamic modeling. An experimental phase equilibrium study was performed to evaluate the absorption of carbon dioxide in aqueous solutions of five representative alkanolamines, including monoethanolamine, diethanolamine, N-methyldiethanolamine, 2-amino-2-methyl-1-propanol and piperazine. The carbon dioxide loadings of these solutions were determined for a wide range of pressures (62.5 kPa to 4150 kPa), temperatures (303.15 K to 343.15 K) and alkanolamine concentrations (2 M to 4 M). The results were found to be largely consistent with those previously reported in the literature. Furthermore, a hybrid Kent-Eisenberg model was developed for the correlation of the experimental data points. This new model incorporated an equation of state/excess Gibbs energy model for determining the solubility of carbon dioxide in the high-pressure-high gas loading region. This approach also used a single correction parameter, which was a function of the alkanolamine concentration. The results of this model were in excellent agreement with our experimental results. Most notably, this model was consistent with other reported values from the literature.

  16. Alternative chromatographic system for the quality control of lipophilic technetium-99m radiopharmaceuticals such as [{sup 99m}Tc(MIBI){sub 6}]{sup +}

    Faria, D.P.; Buchpiguel, C.A.; Marques, F.L.N., E-mail: danielefaria1@gmail.com [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Departamento de Radiologia. Servico de Medicina Nuclear

    2015-10-15

    Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [{sup 99m}Tc(MIBI){sub 6}]{sup +} as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol: chloroform (25:75), Whatman 3MM paper and ethanol:chloroform (25:75), and the more expensive ITLC-SG and 1-propanol: chloroform (10:90) were suitable systems for the direct determination of radiochemical purity of [{sup 99m}Tc(MIBI){sub 6}]{sup +} since impurities such as {sup 99m}Tc-reduced-hydrolyzed (RH), {sup 99m}TcO4{sup -} and [{sup 99m}Tc(cysteine){sub 2}]{sup -} complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines. (author)

  17. Single-experiment simultaneous-measurement of elemental mass-attenuation coefficients of hydrogen, carbon and oxygen for 0.123-1.33 MeV gamma rays

    As it is inconvenient to use elements like hydrogen, carbon and oxygen in pure forms for measurement of their gamma mass-attenuation coefficients, the measurements are to be done indirectly, by using compounds of the elements or a mixture of them. We give here a simple method of measuring the total mass-attenuation coefficients μ/ρ of the elements in a compound simultaneously and in a single experiment through the measurements of the μ/ρ values of the concerned compounds and using the mixture rule. The method is applied for the measurement of μ/ρ of hydrogen, carbon and oxygen by using acetone, ethanol and 1-propanol. Our results (for Eγ=0.123-1.33 MeV) are seen to be in better agreement with the theoretical values of Hubbell and Seltzer (1995) [Hubbell J.H. and Seltzer S.M. (1995). Tables of X-ray mass attenuation coefficients and mass energy-absorption coefficients 1 keV to 20 MeV for elements Z=1 to 92 and 48 additional substances of dosimetric interest. NISTIR 5632] as compared to the results of El-Kateb and Abdul-Hamid (1991) [El-Kateb, A.H., Abdul-Hamid, A.S., 1991. Photon attenuation coefficient study of some materials containing hydrogen, carbon, and oxygen. Appl. Rad. Isot. 42, 303-307

  18. Protease activation in glycerol-based deep eutectic solvents

    Zhao, Hua; Baker, Gary A.; Holmes, Shaletha

    2011-01-01

    Deep eutectic solvents (DESs) consisting of mixtures of a choline salt (chloride or acetate form) and glycerol are prepared as easily accessible, biodegradable, and inexpensive alternatives to conventional aprotic cation-anion paired ionic liquids. These DES systems display excellent fluidity coupled with thermal stability to nearly 200 °C. In this work, the transesterification activities of cross-linked proteases (subtilisin and α-chymotrypsin), immobilized on chitosan, were individually examined in these novel DESs. In the 1:2 molar ratio mixture of choline chloride/glycerol containing 3% (v/v) water, cross-linked subtilisin exhibited an excellent activity (2.9 μmo l min−1 g−1) in conjunction with a selectivity of 98% in the transesterification reaction of N-acetyl-L-phenylalanine ethyl ester with 1-propanol. These highly encouraging results advocate more extensive exploration of DESs in protease-mediated biotransformations of additional polar substrates and use of DESs in biocatalysis more generally. PMID:21909232

  19. Highly conductive side chain block copolymer anion exchange membranes.

    Wang, Lizhu; Hickner, Michael A

    2016-06-28

    Block copolymers based on poly(styrene) having pendent trimethyl styrenylbutyl ammonium (with four carbon ring-ionic group alkyl linkers) or benzyltrimethyl ammonium groups with a methylene bridge between the ring and ionic group were synthesized by reversible addition-fragmentation radical (RAFT) polymerization as anion exchange membranes (AEMs). The C4 side chain polymer showed a 17% increase in Cl(-) conductivity of 33.7 mS cm(-1) compared to the benzyltrimethyl ammonium sample (28.9 mS cm(-1)) under the same conditions (IEC = 3.20 meq. g(-1), hydration number, λ = ∼7.0, cast from DMF/1-propanol (v/v = 3 : 1), relative humidity = 95%). As confirmed by small angle X-ray scattering (SAXS), the side chain block copolymers with tethered ammonium cations showed well-defined lamellar morphologies and a significant reduction in interdomain spacing compared to benzyltrimethyl ammonium containing block copolymers. The chemical stabilities of the block copolymers were evaluated under severe, accelerated conditions, and degradation was observed by (1)H NMR. The block copolymer with C4 side chain trimethyl styrenylbutyl ammonium motifs displayed slightly improved stability compared to that of a benzyltrimethyl ammonium-based AEM at 80 °C in 1 M NaOD aqueous solution for 30 days. PMID:27216558

  20. Volumetric and viscometric properties of binary mixtures of {methyl tert-butyl ether (MTBE) + alcohol} at several temperatures and p = 0.1 MPa: Experimental results and application of the ERAS model

    Highlights: → Binary mixtures of MTBE + alcohol have been studied. → Volumetric and viscometric properties have been determined at several temperatures. → Excess molar volumes have been used to test the applicability of the ERAS model. → The results are discussed in terms of chemical and structural effects. - Abstract: Densities and viscosities of binary mixtures of {methyl tert-butyl ether (MTBE) + methanol, or +ethanol, or +1-propanol, or +2-propanol, or +1-butanol, or +1-pentanol, or +1-hexanol} have been determined as a function of composition at several temperatures and atmospheric pressure. The temperatures studied were (293.15, 298.15, 303.15, and 308.15) K. The experimental results have been used to calculate the excess molar volume (VmE) and viscosity deviation (Δη). Both VmE and Δη values were negative over the entire range of mole fraction for all temperatures and systems studied. Moreover, the VmE values have been used to test the applicability of the Extended Real Associated Solution (ERAS) model.

  1. Solubilities of some organic solutes in 1-ethyl-3-methylimidazolium acetate. Chromatographic measurements and predictions from COSMO-RS

    Highlights: ► New solubility data are reported. ► Two experimental procedures for measuring solubilities are used. ► The experimental results from both procedures are compared. ► Experiments are compared with the theoretical calculations. - Abstract: Infinite-dilution activity coefficients and Henry’s constants for several organic solutes in 1-ethyl-3-methylimidazolium acetate [EMIM][Ac] were measured from T = 313 K to T = 413 K using two types of gas–liquid chromatography columns: packed columns and an open tubular wall-coated (OTWC) column. The organic solutes include n-hexane, 1-hexene, cyclohexane, heptane, benzene, toluene, ethyl acetate, tetrahydrofuran, 1,4-dioxane, acetonitrile, nitromethane, 1,2-methoxyethane, 1-propanol, 2-propanol, t-butanol and t-amyl alcohol. Results using packed columns are in good agreement with those using the OTWC column. However, there is a useful advantage associated with an OTWC column: for solutes such as alcohols, that have strong interactions with the stationary phase, measurements are faster due to their shorter retention time compared to those in packed columns.

  2. Comparisons of amine solvents for post-combustion CO{sub 2} capture: A multi-objective analysis approach

    Lee, Anita S; Eslick, John C; Miller, David C; Kitchin, John R

    2013-10-01

    Amine solvents are of great interest for post-combustion CO{sub 2} capture applications. Although the development of new solvents is predominantly conducted at the laboratory scale, the ability to assess the performance of newly developed solvents at the process scale is crucial to identifying the best solvents for CO{sub 2} capture. In this work we present a methodology to evaluate and objectively compare the process performance of different solvents. We use Aspen Plus, with the electrolyte-NRTL thermodynamic model for the solvent CO{sub 2} interactions, coupled with a multi-objective genetic algorithm optimization to determine the best process design and operating conditions for each solvent. This ensures that the processes utilized for the comparison are those which are best suited for the specific solvent. We evaluate and compare the process performance of monoethanolamine (MEA), diethanolamine (DEA), and 2-amino-2-methyl-1-propanol (AMP) in a 90% CO{sub 2} capture process from a 550 MW coal fired power plant. From our analysis the best process specifications are amine specific and with those specific, optimized specifications DEA has the potential to be a better performing solvent than MEA, with a lower energy penalty and lower capital cost investment.

  3. Simple cerium-triethanolamine complex: Synthesis, characterization, thermal decomposition and its application to prepare ceria support for platinum catalysts used in methane steam reforming

    Wattanathana, Worawat; Nootsuwan, Nollapan; Veranitisagul, Chatchai; Koonsaeng, Nattamon; Laosiripojana, Navadol; Laobuthee, Apirat

    2015-06-01

    Cerium-triethanolamine complex was synthesized by simple complexation method in 1-propanol solvent using cerium(III) chloride as a metal source and triethanolamine as a ligand. The structures of the prepared complex were proposed based on FT-IR, FT-Raman and ESI-MS results as equimolar of triethanolamine and cerium chelated complex having monomeric tricyclic structure with and without chloride anion as another coordinating group known as ceratrane. The complex was used as a precursor for ceria material done by thermal decomposition. XRD result revealed that when calcined at 600 °C for 2 h, the cerium complex was totally turned into pure ceria with cubic fluorite structure. The obtained ceria was then employed to synthesize platinum doped ceria catalysts for methane steam reforming. Various amounts of platinum i.e. 1, 3, 5 and 10 mol percents were introduced on the ceria support by microwave-assisted wetness impregnation using ammonium tetrachloroplatinate(II). The platinum-impregnated ceria powders were subjected to calcination in 10% hydrogen/helium atmosphere at 500 °C for 3 h to reduce platinum(II) to platinum(0). XRD patterns of the catalysts confirmed that the platinum particles doped on the ceria support were in the form of platinum(0). Catalytic activity test showed that the catalytic activities got higher as the amounts of platinum doped increased. Besides, the portions of coke formation on the surface of catalysts were reduced as the amounts of platinum doped increased.

  4. Avaliação cromatográfica de compostos voláteis de cachaças produzidas com leveduras de diferentes procedências Chromatographic evaluation of volatile compounds in brazilian sugar cane spirits produced with yeasts from different locations

    Paulo Henrique Alves da Silva

    2009-03-01

    Full Text Available Procurou-se neste trabalho produzir cachaças em escala de laboratório a partir de leveduras isoladas de alambiques de diferentes regiões de Minas Gerais, avaliando-se e comparando-se a composição química destas em relação a cachaças de marcas comerciais. Os alambiques selecionados para isolamento das leveduras produzem tradicionalmente cachaças com características artesanais, cujos procedimentos as diferenciam sensorial e quimicamente das cachaças industriais. Avaliou-se a cinética de algumas das fermentações com relação ao teor alcoólico e à acidez produzidos durante a fermentação e alguns mostos atingiram concentrações de etanol da ordem de 9 ºGL e acidez de 55 mg.100 mL-1. Os compostos avaliados por cromatografia gasosa foram acetaldeído, acetato de etila, metanol, 1-propanol, álcool isobutílico, álcool isoamílico, furfural e ácido acético. As concentrações mais elevadas foram de alcoóis superiores totais, preponderando o álcool isoamílico, e de ácido acético. A composição mostrou-se bastante variável (40,59 a 671,86 mg de ácido acético.100 mL-1 de álcool anidro e 20,68 a 178,6 mg de acetaldeído.100 mL-1 de álcool anidro, e foi contrastada com os limites legais estabelecidos pela legislação brasileira (Instrução Normativa nº 13, de 30/06/2005, do Ministério da Agricultura, Pecuária e Abastecimento.The aim of this study was to produce Brazilian sugar cane spirits (cachaça in a laboratory scale using yeasts isolated from distilleries of different regions in Minas Gerais state evaluating and comparing their chemical composition to those of commercial brands of cachaça. The selected distilleries are from the segment of cachaça artisanal production, which includes different sensorial and chemical procedures from the ones produced in an industrial scale. Some kinetic processes were evaluated analyzing the alcoholic content and acidity produced during fermentation. Some fermenting musts showed

  5. Glioma cell death induced by irradiation or alkylating agent chemotherapy is independent of the intrinsic ceramide pathway.

    Dorothee Gramatzki

    Full Text Available BACKGROUND/AIMS: Resistance to genotoxic therapy is a characteristic feature of glioma cells. Acid sphingomyelinase (ASM hydrolyzes sphingomyelin to ceramide and glucosylceramide synthase (GCS catalyzes ceramide metabolism. Increased ceramide levels have been suggested to enhance chemotherapy-induced death of cancer cells. METHODS: Microarray and clinical data for ASM and GCS in astrocytomas WHO grade II-IV were acquired from the Rembrandt database. Moreover, the glioblastoma database of the Cancer Genome Atlas network (TCGA was used for survival data of glioblastoma patients. For in vitro studies, increases in ceramide levels were achieved either by ASM overexpression or by the GCS inhibitor DL-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (PPMP in human glioma cell lines. Combinations of alkylating chemotherapy or irradiation and ASM overexpression, PPMP or exogenous ceramide were applied in parental cells. The anti-glioma effects were investigated by assessing proliferation, metabolic activity, viability and clonogenicity. Finally, viability and clonogenicity were assessed in temozolomide (TMZ-resistant cells upon treatment with PPMP, exogenous ceramide, alkylating chemotherapy, irradiation or their combinations. RESULTS: Interrogations from the Rembrandt and TCGA database showed a better survival of glioblastoma patients with low expression of ASM or GCS. ASM overexpression or PPMP treatment alone led to ceramide accumulation but did not enhance the anti-glioma activity of alkylating chemotherapy or irradiation. PPMP or exogenous ceramide induced acute cytotoxicity in glioblastoma cells. Combined treatments with chemotherapy or irradiation led to additive, but not synergistic effects. Finally, no synergy was found when TMZ-resistant cells were treated with exogenous ceramide or PPMP alone or in combination with TMZ or irradiation. CONCLUSION: Modulation of intrinsic glioma cell ceramide levels by ASM overexpression or GCS

  6. Scleroglucan compatibility with thickeners, alcohols and polyalcohols and downstream processing implications.

    Viñarta, Silvana C; Yossen, Mariana M; Vega, Jorge R; Figueroa, Lucía I C; Fariña, Julia I

    2013-02-15

    Thickening capacity and compatibility of scleroglucan with commercial thickeners (corn starch, gum arabic, carboxymethylcellulose, gelatin, xanthan and pectin), glycols (ethylene glycol and polyethylene glycol), alcohols (methanol, ethanol, 1-propanol and isopropanol) and polyalcohols (sorbitol, xylitol and mannitol) was explored. Exopolysaccharides (EPSs) from Sclerotium rolfsii ATCC 201126 and a commercial scleroglucan were compared. Compatibility and synergism were evaluated taking into account rheology, pH and sensory properties of different thickener/scleroglucan mixtures in comparison with pure solutions. S. rolfsii ATCC 201126 EPSs induced or increased pseudoplastic behaviour with a better performance than commercial scleroglucan, showing compatibility and synergy particularly with corn starch, xanthan, pectin and carboxymethylcellulose. Compatibility and a slight synergistic behaviour were also observed with 30% (w/v) ethylene glycol whereas mixtures with polyethylene glycol (PEG) precipitated. Scleroglucan was compatible with polyalcohols, whilst lower alcohols led to scleroglucan precipitation at 20% (v/v) and above. PEG-based scleroglucan downstream processing was compared to the usual alcohol precipitation. Downstream processed EPSi (with isopropanol) and EPS-p (with PEG) were evaluated on their yield, purity, rheological properties and visual aspect pointing to alcohol downstream processing as the best methodology, whilst PEG recovery would be unsuitable. The highest purified EPSi attained a recovery yield of ~23%, similar to ethanol purification, with a high degree of purity (88%, w/w vs. EPS-p, 8%, w/w) and exhibited optimal rheological properties, water solubility and appearance. With a narrower molecular weight distribution (M(w), 2.66×10(6) g/mol) and a radius of gyration (R(w), 245 nm) slightly lower than ethanol-purified EPSs, isopropanol downstream processing showed to be a proper methodology for obtaining a refined-grade scleroglucan. PMID

  7. Time-activity relationships to VOC personal exposure factors

    Edwards, Rufus D.; Schweizer, Christian; Llacqua, Vito; Lai, Hak Kan; Jantunen, Matti; Bayer-Oglesby, Lucy; Künzli, Nino

    Social and demographic factors have been found to play a significant role in differences between time-activity patterns of population subgroups. Since time-activity patterns largely influence personal exposure to compounds as individuals move across microenvironments, exposure subgroups within the population may be defined by factors that influence daily activity patterns. Socio-demographic and environmental factors that define time-activity subgroups also define quantifiable differences in VOC personal exposures to different sources and individual compounds in the Expolis study. Significant differences in exposures to traffic-related compounds ethylbenzene, m- and p-xylene and o-xylene were observed in relation to gender, number of children and living alone. Categorization of exposures further indicated time exposed to traffic at work and time in a car as important determinants. Increased exposures to decane, nonane and undecane were observed for males, housewives and self-employed. Categorization of exposures indicated exposure subgroups related to workshop use and living downtown. Higher exposures to 3-carene and α-pinene commonly found in household cleaning products and fragrances were associated with more children, while exposures to traffic compounds ethylbenzene, m- and p-xylene and o-xylene were reduced with more children. Considerable unexplained variation remained in categorization of exposures associated with home product use and fragrances, due to individual behavior and product choice. More targeted data collection methods in VOC exposure studies for these sources should be used. Living alone was associated with decreased exposures to 2-methyl-1-propanol and 1-butanol, and traffic-related compounds. Identification of these subgroups may help to reduce the large amount of unexplained variation in VOC exposure studies. Further they may help in assessing impacts of urban planning that result in changes in behavior of individuals, resulting in shifts in

  8. [Influences of uncommon isoenzymes on determination of alkaline phosphatase activity by dry-chemistry analyzers].

    Tozawa, T; Hashimoto, M

    2001-04-01

    Dry-chemistry(DC) analysis may be influenced by some matrix effects for measuring uncommon isoenzyme forms. Placental and intestinal alkaline phosphatase(AP) are overestimated by the VITROS DC, compared with results obtained with the wet-chemistry(WC) method of Bretaudiere, et al. using 2-amino-2-methyl-1-propanol (AMP) buffer, however, no such discrepancy between AP results in any DC method and that with a routine WC method recommended by Japanese Society of Clinical Chemistry in that 2-ethylaminoethanol(EAE) buffer is used, has been demonstrated. The type of buffer used affects differently the rates of AP isoenzymes activities. We therefore examined whether the presence of uncommon AP isoenzyme forms in serum caused aberrant DC results for AP in comparison with a routine WC method using EAE buffer. Here, serum samples with only liver AP and bone AP(n : 32); high-molecular-mass AP(n : 11); placental AP(n : 12); intestinal AP(n : 13) and immunoglobulin (Ig) bound AP(n : 12) were analyzed for total AP activity on three different DC analyzers: VITROS 700XR, FUJIDRYCHEM 5000, SPOTCHEM 4410 and a WC analyzer: HITACHI 7350. Values obtained in all of the DCs for sera containing only liver/bone AP agreed with those with the WC method. For sera containing placental AP, the VITROS values were higher than those with the WC method, while the FUJIDRYCHEM values and the SPOTCHEM values were lower. The VITROS values and the FUJIDRYCHEM values for sera containing intestinal AP were lower than those with the WC method, while the SPOTCHEM values were higher. All of the DCs did not affect high-molecular-mass AP and Ig bound liver/bone AP types of macro AP, but underestimated Ig bound intestinal type. Ig bound intestinal AP may be sieved by DC multilayer elements. PMID:11391954

  9. Picosecond spectral relaxation of curcumin excited state in toluene–alcohol mixtures

    Saini, R.K.; Das, K., E-mail: kaustuv@rrcat.gov.in

    2013-12-15

    Excited state photophysics of Curcumin in a binary solvent mixture of toluene and five different alcohols (Methanol, Ethanol, 1-Propanol, 1-Butanol and 1-Octanol) are compared with an instrument time resolution of ∼40 ps. As the alcohol mole-fraction is varied from zero to unity, the observed trends in the fluorescence quantum yield and lifetime of the pigment in toluene–alcohol mixtures changes significantly in going from Methanol to 1-Octanol. This is attributed to the different degree of modulation of the non-radiative rates associated with the excited state intermolecular H bonding between the pigment and the alcohol. Fluorescence decays taken at the red edge of the emission spectrum started to show measurable rise times (200–30 ps) the magnitude of which decreased gradually with increasing alcohol mole-fraction. As a consequence the solvation times in the binary mixture were observed to slow down considerably at certain solvent compositions compared to that in neat alcohol. However, in toluene-1-Octanol mixture, the rise times and corresponding solvation times did not show a dependence on the 1-Octanol mole-fraction. The observed results suggest that viscosity, polarity and hydrogen bonding property of the alcohol solvent plays an important role in the excited state processes of the pigment in toluene–alcohol mixture. -- Highlights: • Excited state photophysics of Curcumin in a binary solvent mixture of toluene and five different alcohols were studied. • The observed trends in the fluorescence properties are attributed to intermolecular H bonding between the pigment and the alcohol. • Except 1-Octanol, the average solvation times of the pigment were observed to depend upon alcohol mole-fraction. • Viscosity, polarity and hydrogen bonding play an important role in the excited state processes of the pigment.

  10. Separation of several alcohol-benzene mixtures by pervaporation through styrene graft polyethylene membranes

    The permeation of pure liquids, such as methanol, ethanol, 1-propanol, 2-propanol and benzene, and the permeability and selectivity of 50 vol% binary mixtures of these alcohols and benzene were investigated by pervaporation technique. The used membranes (21%, 40%, and 72% graftings) were obtained by graft polymerization of styrene to polyethylene film (thickness 10 μm) by γ-radiation. The permeation rates of each of these alcohols and benzene were measured by pervaporation through the graft membranes. Those of these alcohols were very small as well as those through the original membrane. On the other hand, the permeabilities for benzene through the graft membranes were larger than that through the original membrane. The temperature dependence of the permeation rate for benzene was expressed by Arrhenius-type relationships, and the apparent activation energies were calculated to be 10.7 (21%), 10.2 (40%) and 10.0 (72%) kcal/mol. In the permeation of 50 vol% several alcohol-benzene mixtures, the permeabilities through the graft membranes were also larger than that through the original membrane, and increased with the grafting. The temperature dependence of the permeation for these mixtures was showed by Arrhenius relationships, and the apparent activation energies were calculated to be in the range of 8.4∼11.0 kcal/mol. The separation factors of the graft membranes calculated from composition of the permeates were always smaller than that of the original membrane, but became larger with increase of molecular volume of alcohol in alcohol-benzene mixtures. (author)

  11. Thermodynamic Stability Analysis of Tolbutamide Polymorphs and Solubility in Organic Solvents.

    Svärd, Michael; Valavi, Masood; Khamar, Dikshitkumar; Kuhs, Manuel; Rasmuson, Åke C

    2016-06-01

    Melting temperatures and enthalpies of fusion have been determined by differential scanning calorimetry (DSC) for 2 polymorphs of the drug tolbutamide: FI(H) and FV. Heat capacities have been determined by temperature-modulated DSC for 4 polymorphs: FI(L), FI(H), FII, FV, and for the supercooled melt. The enthalpy of fusion of FII at its melting point has been estimated from the enthalpy of transition of FII into FI(H) through a thermodynamic cycle. Calorimetric data have been used to derive a quantitative polymorphic stability relationship between these 4 polymorphs, showing that FII is the stable polymorph below approximately 333 K, above which temperature FI(H) is the stable form up to its melting point. The relative stability of FV is well below the other polymorphs. The previously reported kinetic reversibility of the transformation between FI(L) and FI(H) has been verified using in situ Raman spectroscopy. The solid-liquid solubility of FII has been gravimetrically determined in 5 pure organic solvents (methanol, 1-propanol, ethyl acetate, acetonitrile, and toluene) over the temperature range 278 to 323 K. The ideal solubility has been estimated from calorimetric data, and solution activity coefficients at saturation in the 5 solvents determined. All solutions show positive deviation from Raoult's law, and all van't Hoff plots of solubility data are nonlinear. The solubility in toluene is well below that observed in the other investigated solvents. Solubility data have been correlated and extrapolated to the melting point using a semiempirical regression model. PMID:27238487

  12. The same microbiota and a potentially discriminant metabolome in the saliva of omnivore, ovo-lacto-vegetarian and Vegan individuals.

    De Filippis, Francesca; Vannini, Lucia; La Storia, Antonietta; Laghi, Luca; Piombino, Paola; Stellato, Giuseppina; Serrazanetti, Diana I; Gozzi, Giorgia; Turroni, Silvia; Ferrocino, Ilario; Lazzi, Camilla; Di Cagno, Raffaella; Gobbetti, Marco; Ercolini, Danilo

    2014-01-01

    The salivary microbiota has been linked to both oral and non-oral diseases. Scant knowledge is available on the effect of environmental factors such as long-term dietary choices on the salivary microbiota and metabolome. This study analyzed the microbial diversity and metabolomic profiles of the saliva of 161 healthy individuals who followed an omnivore or ovo-lacto-vegetarian or vegan diet. A large core microbiota was identified, including 12 bacterial genera, found in >98% of the individuals. The subjects could be stratified into three "salivary types" that differed on the basis of the relative abundance of the core genera Prevotella, Streptococcus/Gemella and Fusobacterium/Neisseria. Statistical analysis indicated no effect of dietary habit on the salivary microbiota. Phylogenetic beta-diversity analysis consistently showed no differences between omnivore, ovo-lacto-vegetarian and vegan individuals. Metabolomic profiling of saliva using (1)H-NMR and GC-MS/SPME identified diet-related biomarkers that enabled a significant discrimination between the 3 groups of individuals on the basis of their diet. Formate, urea, uridine and 5-methyl-3-hexanone could discriminate samples from omnivores, whereas 1-propanol, hexanoic acid and proline were characteristic of non-omnivore diets. Although the salivary metabolome can be discriminating for diet, the microbiota has a remarkable inter-individual stability and did not vary with dietary habits. Microbial homeostasis might be perturbed with sub-standard oral hygiene or other environmental factors, but there is no current indication that a choice of an omnivore, ovo-lacto-vegetarian or vegan diet can lead to a specific composition of the oral microbiota with consequences on the oral homeostasis. PMID:25372853

  13. Ruminal Fermentation of Anti-Methanogenic Nitrate- and Nitro-Containing Forages In Vitro

    Anderson, Robin C.; Ripley, Laura H.; Bowman, Jan G. P.; Callaway, Todd R.; Genovese, Kenneth J.; Beier, Ross C.; Harvey, Roger B.; Nisbet, David J.

    2016-01-01

    Nitrate, 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) can accumulate in forages and be poisonous to animals if consumed in high enough amounts. These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied little in this regard. Presently, we found that nitrate-, NPA-, or NPOH-containing forages effectively decreased methane production, by 35–87%, during in vitro fermentation by mixed cultures of ruminal microbes compared to fermentation by cultures incubated similarly with alfalfa. Methane production was further decreased during the incubation of mixed cultures also inoculated with Denitrobacterium detoxificans, a ruminal bacterium known to metabolize nitrate, NPA, and NPOH. Inhibition of methanogens within the mixed cultures was greatest with the NPA- and NPOH-containing forages. Hydrogen accumulated in all the mixed cultures incubated with forages containing nitrate, NPA or NPOH and was dramatically higher, exceeding 40 μmol hydrogen/mL, in mixed cultures incubated with NPA-containing forage but not inoculated with D. detoxificans. This possibly reflects the inhibition of hydrogenase-catalyzed uptake of hydrogen produced via conversion of 50 μmol added formate per milliliter to hydrogen. Accumulations of volatile fatty acids revealed compensatory changes in fermentation in mixed cultures incubated with the nitrate-, NPA-, and NPOH-containing forages as evidenced by lower accumulations of acetate, and in some cases, higher accumulations of butyrate and lower accumulations of ammonia, iso-buytrate, and iso-valerate compared to cultures incubated with alfalfa. Results reveal that nitrate, NPA, and NPOH that accumulate naturally in forages can be made available within ruminal incubations to inhibit methanogenesis. Further research is warranted to determine if diets can be formulated with nitrate-, NPA-, and NPOH-containing forages to achieve efficacious mitigation

  14. Development and validation of LC methods for the separation of misoprostol related substances and diastereoisomers.

    Kahsay, Getu; Song, Huiying; Eerdekens, Fran; Tie, Yaxin; Hendriks, Danny; Van Schepdael, Ann; Cabooter, Deirdre; Adams, Erwin

    2015-01-01

    Misoprostol is a synthetic prostaglandin E1 analogue which is mainly used for prevention and treatment of gastric ulcers, but also for abortion due to its labour inducing effect. Misoprostol exists as a mixture of diastereoisomers (1:1) and has several related impurities owing to its instability at higher temperatures and moisture. A simple and robust reversed phase liquid chromatographic (RPLC) method is described for the separation of the related substances and a normal phase (NP) LC method for the separation of misoprostol diastereoisomers. The RPLC method was performed using an Ascentis Express C18 (150 mm × 4.6 mm, 5 μm) column kept at 35 °C. The mobile phase was a gradient mixture of mobile phase A (ACN-H2O-MeOH, 28:69:3 v/v/v) and mobile phase B (ACN-H2O-MeOH, 47:50:3 v/v/v) eluted at a flow rate of 1.5 mL/min. UV detection was performed at 200 nm. The NPLC method was undertaken by using an XBridge bare silica (150 mm × 2.1 mm, 3.5 μm) column at 35 °C. The mobile phase contained 1-propanol-heptane-TFA (4:96:0.1%, v/v/v), pumped at a flow rate of 0.5 mL/min. UV detection was performed at 205 nm. This LC method can properly separate the two diastereoisomers (Rs > 2) within an analysis time of less than 20 min. Both methods were validated according to the ICH guidelines. Furthermore, these new LC methods have been successfully applied for purity control and diastereoisomers ratio determination of misoprostol bulk drug, tablets and dispersion. PMID:25880239

  15. Influence on the interaction by functional groups in some series of bicyclo (2,2,1) heptane derivatives

    In connection with investigations involving the interactions of substituted groups in the bicyclo (2,2,1) heptane molecules, the chemical reactivity and some physical properties of polyfunctional compounds have been studied. A new method for preparation of β-fenchylic derivatives is presented, the first described terpenic nitroxide radical have been prepared from oxazolidinic compounds. The stereochemistry of the base induced elimination reaction of 6-exo tosyl and 6-endo tosyl oxy epi-camphor is dependent of the geometry of these compounds. On the other hand, the results indicate that the most important part of the structure is the position of the carbonyl group. Tricyclenic and camphenic derivatives are obtained with different rates. An explanation for these results involve several possible basic abstractions of acid protons, and the competition between these different reactions. The oxazolidinic compounds are obtained by reacting 2-amino 2-methyl 1-propanol with norcamphor and norbornane-2,5 dione. The geometrical configuration of the different stereoisomers is deduced from the measured dipolar interaction parameter D. The cotton effects of the γ-diketones do not show any interaction between the two carbonyl groups, in the fenchylic and bornylic series. The two carbonyl bond angles of the substituted α-diketones do not seem to be sensitive to any substitution of an alkoxy group. So, a new quadrant rule is proposed; compatible results are obtained, except for a methyl group in the α position. At least, PMR studies of terpenic polyfunctional compounds demonstrate the influence of the substitution on the geometry of the carbon skeleton. A new coupling constant 4JHH is examined. (author)

  16. Pesticide analysis in rose wines by micellar electrokinetic chromatography.

    Ravelo-Pérez, Lidia M; Hernández-Borges, Javier; Borges-Miquel, Teresa M; Rodríguez-Delgado, Miguel Angel

    2007-12-01

    In this work, the determination of 11 pesticides (pirimicarb, metalaxyl, pyrimethanil, procymidone, nuarimol, azoxystrobin, tebufenozide, fenarimol, benalaxyl, penconazole, and tetradifon) in rose wines by micellar EKC (MEKC) using reversed electrode polarity stacking mode (REPSM) as online preconcentration strategy is described. The MEKC buffer consisted of 100 mM sodium tetraborate and 30 mM SDS at pH 8.5 with 6% v/v 1-propanol. A solid-phase microextraction (SPME) procedure using PDMS/divinylbenzene (PDMS/DVB) fibers was applied to extract the selected pesticides from the rose wine samples. The comparison between the calibration curves obtained from hydroalcoholic solutions (12% v/v ethanol) and from rose wines (matrix matched calibration) showed the existence of a strong matrix effect. Furthermore, a comparison with calibration curves obtained with white wine samples also showed significant differences for most of the analyzed pesticides. As a result, a matrix matched calibration was developed. Quantitative extraction from spiked wine samples was carried out in triplicate at two levels of concentration (range 0.18-6.00 mg/L). LODs between 0.040 and 0.929 mg/L were achieved, which are below the maximum residue limits (MRLs) established for wine grapes (except for pirimicarb) by the EU and Spain legislation as well as by the Codex Alimentarius. The established method - which is solvent free, cost effective, and fast - was also applied to the analysis of several homemade rose wine samples and a commercial one. Two of the selected pesticides were found in some of the analyzed samples. PMID:18027361

  17. Ruminal Fermentation of Anti-Methanogenic Nitrate- and Nitro-Containing Forages In Vitro.

    Anderson, Robin C; Ripley, Laura H; Bowman, Jan G P; Callaway, Todd R; Genovese, Kenneth J; Beier, Ross C; Harvey, Roger B; Nisbet, David J

    2016-01-01

    Nitrate, 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) can accumulate in forages and be poisonous to animals if consumed in high enough amounts. These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied little in this regard. Presently, we found that nitrate-, NPA-, or NPOH-containing forages effectively decreased methane production, by 35-87%, during in vitro fermentation by mixed cultures of ruminal microbes compared to fermentation by cultures incubated similarly with alfalfa. Methane production was further decreased during the incubation of mixed cultures also inoculated with Denitrobacterium detoxificans, a ruminal bacterium known to metabolize nitrate, NPA, and NPOH. Inhibition of methanogens within the mixed cultures was greatest with the NPA- and NPOH-containing forages. Hydrogen accumulated in all the mixed cultures incubated with forages containing nitrate, NPA or NPOH and was dramatically higher, exceeding 40 μmol hydrogen/mL, in mixed cultures incubated with NPA-containing forage but not inoculated with D. detoxificans. This possibly reflects the inhibition of hydrogenase-catalyzed uptake of hydrogen produced via conversion of 50 μmol added formate per milliliter to hydrogen. Accumulations of volatile fatty acids revealed compensatory changes in fermentation in mixed cultures incubated with the nitrate-, NPA-, and NPOH-containing forages as evidenced by lower accumulations of acetate, and in some cases, higher accumulations of butyrate and lower accumulations of ammonia, iso-buytrate, and iso-valerate compared to cultures incubated with alfalfa. Results reveal that nitrate, NPA, and NPOH that accumulate naturally in forages can be made available within ruminal incubations to inhibit methanogenesis. Further research is warranted to determine if diets can be formulated with nitrate-, NPA-, and NPOH-containing forages to achieve efficacious mitigation in

  18. Influence of Sol-Gel Conditions on the Growth of Thiol-Functionalized Silsesquioxanes Prepared by In Situ Water Production.

    Borovin, Evgeny; Callone, Emanuela; Papendorf, Benjamin; Guella, Graziano; Diré, Sandra

    2016-03-01

    Thiol-functionalized oligosilsesquioxanes have been synthesized by sol-gel chemistry via the in-situ water production (ISWP) approach, exploiting the esterification reaction of chloro-acetic acid and 1-propanol. The extent of hydrolysis-condensation of 3-Mercaptopropyltrimethoxysilane (McPTMS) has been studied by FT-IR and NMR spectroscopy, gel permeation chromatography (GPC) and MALDI-TOF techniques. The esterification reaction plays a key role in ruling out the oligomer structural development. In this work, we have investigated the influence of the theoretical amount of water available for the organosilane hydrolysis, defined by the ratio of chloro-acetic acid to McPTMS in the reaction mixture, and the role of different catalysts like trifluoroacetic acid (TFA) and dibutyldilauryltin (DBTL). The behavior of the catalyst is complex since, according to its nature, it may improve the kinetics of the sol-gel reactions and the esterification reaction as well. Comparing the reactions carried out with under-stoichiometric water content, the degree of condensation of the silsesquioxanes is higher if the reaction is catalyzed by TFA than by DBTL, because TFA may improve the kinetics of both hydrolysis-condensation and esterification reactions. The use of DBTL in under-stoichiometric and stoichiometric hydrolytic conditions raises the yield in ladder-like structures. The degree of condensation generally increases increasing the hydrolysis ratio as well as the yield in cage-like structures. However, when an over-stoichiometric amount of water is provided for the sol-gel reaction, condensation degree and ratio among cages and ladder-like structures appear unaffected by the employed catalyst. PMID:27455755

  19. Determinação das composições físico-químicas de cachaças do sul de minas gerais e de suas misturas Determination of the physical-chemical composition of homemade cachaças produced in the South of Minas Gerais and their mixtures

    Fernando José Vilela

    2007-08-01

    Full Text Available Este trabalho teve por objetivo a determinação da composição físico-química de cachaças artesanais produzidas no sul do Estado de Minas Gerais e suas misturas. Foram analisados os teores de etanol, acidez volátil, aldeídos, cobre, ésteres, álcoois superiores totais e metanol, além dos álcoois propanol-1, isobutanol e 3-metil-butanol-1. Os resultados apresentam o perfil peculiar desta bebida, que apresentou teores satisfatórios de álcoois superiores, ésteres e aldeídos. O teor de cobre apresenta-se como preocupante já que algumas amostras excederam o limite de 5 mg.L-1. A produção de misturas foi estudada e esta apresenta-se como uma alternativa viável ao produtor e cooperativas.The present study sought the physical-chemical composition of homemade cachaças produced in the south of the state Minas Gerais and of mixtures of the same cachaça samples. The ethanol, aldehyde, copper, higher alcohol, volatile acid and methanol concentrations were determined, in addition to the individual propanol, 2-methyl-1-propanol and 3-methyl-1-butanol concentrations. The results demonstrated the characteristic profile of this beverage, which presented satisfactory concentrations of higher alcohols, esters, and aldehydes. The copper concentrations of some samples exceeded the limit of 5 mg. L-1. The mixtures produced from some of the cachaça samples presented a viable alternative for the producers and cooperatives because the concentrations of the components were more adequate for exportation.

  20. Ion Mobility-Mass Spectrometry Reveals the Energetics of Intermediates that Guide Polyproline Folding

    Shi, Liuqing; Holliday, Alison E.; Glover, Matthew S.; Ewing, Michael A.; Russell, David H.; Clemmer, David E.

    2016-01-01

    Proline favors trans-configured peptide bonds in native proteins. Although cis/ trans configurations vary for non-native and unstructured states, solvent also influences these preferences. Water induces the all- cis right-handed polyproline-I (PPI) helix of polyproline to fold into the all- trans left-handed polyproline-II (PPII) helix. Our recent work has shown that this occurs via a sequential mechanism involving six resolved intermediates [Shi, L., Holliday, A.E., Shi, H., Zhu, F., Ewing, M.A., Russell, D.H., Clemmer, D.E.: Characterizing intermediates along the transition from PPI to PPII using ion mobility-mass spectrometry. J. Am. Chem. Soc. 136, 12702-12711 (2014)]. Here, we use ion mobility-mass spectrometry to make the first detailed thermodynamic measurements of the folding intermediates, which inform us about how and why this transition occurs. It appears that early intermediates are energetically favorable because of the hydration of the peptide backbone, whereas late intermediates are enthalpically unfavorable. However, folding continues, as the entropy of the system increases upon successive formation of each new structure. When PPII is immersed in 1-propanol, the PPII→PPI transition occurs, but this reaction occurs through a very different mechanism. Early on, the PPII population splits onto multiple pathways that eventually converge through a late intermediate that continues on to the folded PPI helix. Nearly every step is endothermic. Folding results from a stepwise increase in the disorder of the system, allowing a wide-scale search for a critical late intermediate. Overall, the data presented here allow us to establish the first experimentally determined energy surface for biopolymer folding as a function of solution environment.

  1. Effect of ether glycerol lipids on interleukin-1β release and experimental autoimmune encephalomyelitis.

    Boomkamp, Stephanie D; Byun, Hoe-Sup; Ubhi, Satvir; Jiang, Hui-Rong; Pyne, Susan; Bittman, Robert; Pyne, Nigel J

    2016-01-01

    We have assessed the effect of two ether glycerol lipids, 77-6 ((2S, 3R)-4-(Tetradecyloxy)-2-amino-1,3-butanediol) and 56-5 ((S)-2-Amino-3-O-hexadecyl-1-propanol), which are substrates for sphingosine kinases, on inflammatory responses. Treatment of differentiated U937 macrophage-like cells with 77-6 but not 56-5 enhanced IL-1β release; either alone or in the presence of LPS. The stimulatory effect of sphingosine or 77-6 on LPS-stimulated IL-1β release was reduced by pretreatment of cells with the caspase-1 inhibitor, Ac-YVAD-CHO, thereby indicating a role for the inflammasome. The enhancement of LPS-stimulated IL-1β release in response to sphingosine, but not 77-6, was reduced by pretreatment of cells with the cathepsin B inhibitor, CA074Me, indicating a role for lysosomal destabilization in the effect of sphingosine. Administration of 56-5 to mice increased disease progression in an experimental autoimmune encephalomyelitis model and this was associated with a considerable increase in the infiltration of CD4(+) T-cells, CD11b(+) monocytes and F4/80(+) macrophages in the spinal cord. 56-5 and 77-6 were without effect on the degradation of myc-tagged sphingosine 1-phosphate 1 receptor in CCL39 cells. Therefore, the effect of 56-5 on EAE disease progression is likely to be independent of the inflammasome or the sphingosine 1-phosphate 1 receptor. However, 56-5 is chemically similar to platelet activating factor and the exacerbation of EAE disease progression might be linked to platelet activating factor receptor signaling. PMID:26187854

  2. Oxovanadium(V) tetrathiacalix[4]arene complexes and their activity as oxidation catalysts.

    Hoppe, Elke; Limberg, Christian

    2007-01-01

    With the aim of modeling reactive moieties and relevant intermediates on the surfaces of vanadium oxide based catalysts during oxygenation/dehydrogenation of organic substrates, mono- and dinuclear vanadium oxo complexes of doubly deprotonated p-tert-butylated tetrathiacalix[4]arene (H4TC) have been synthesized and characterized: PPh4[(H2TC)VOCl(2)] (1) and (PPh4)2[{(H2TC)V(O)(mu-O)}2] (2). According to the NMR spectra of the dissolved complexes they both retain the structures adopted in the crystalline state, as revealed by single-crystal X-ray crystallography. Compounds 1 and 2 were tested as catalysts for the oxidation of alcohols with O(2) at 80 degrees C. Both 1 and 2 efficiently catalyze the oxidation of benzyl alcohol, crotyl alcohol, 1-phenyl-1-propanol, and fluorenol, and in most cases dinuclear complex 2 is more active than mononuclear complex 1. Moreover, the two thiacalixarene complexes 1 and 2 are in many instances more active than oxovanadium(V) complexes containing "classical" calixarene ligands tested previously. Complexes 1 and 2 also show significant activity in the oxidation of dihydroanthracene. Further investigations led to the conclusion that 1 acts as precatalyst that is converted to the active species PPh4[(TC)V==O] (3) at 80 degrees C by double intramolecular HCl elimination. For complex 2, the results of mechanistic investigations indicated that the oxidation chemistry takes place at the bridging oxo ligands and that the two vanadium centers cooperate during the process. The intermediate (PPh4)2[{H2TCV(O)}2(mu-OH)(mu-OC13H9)] (4) was isolated and characterized, also with respect to its reactivity, and the results afforded a mechanistic proposal for a reasonable catalytic cycle. The implications which these findings gathered in solution may have for oxidation mechanisms on the surfaces of V-based heterogeneous catalysts are discussed. PMID:17566134

  3. Preparation and characterization of poly-(methacrylatoethyl trimethylammonium chloride-co-vinylbenzyl chloride-co-ethylene dimethacrylate monolith

    Eko Malis

    2015-05-01

    Full Text Available A polymer monolithic column, poly-(methacrylatoethyltrimethylammonium chloride-co-vinylbenzyl chloride-co-ethylene dimethacrylate or poly-(MATE-co-VBC-co-EDMA was successfully prepared in the current study by one-step thermally initiated in situ polymerization, confined in a steel tubing of 0.5 mm i.d. and 1/16” o.d. The monoliths were prepared from methacrylatoethyltrimethylammonium chloride (MATE and vinylbenzyl chloride (VBC as monomer and ethylene dimethacrylate (EDMA as crosslinker using a binary porogen system of 1-propanol and 1,4-butanediol. The inner wall of steel tubing was pretreated with 3-methacryloxypropyl-trimethoxysilane (MAPS. In order to obtain monolith with adequate column efficiency and low flow resistance, some parameters such as total monomer concentration (%T and crosslinker concentration (%C were optimized. The morphology of this monolith was assessed by scanning electron microscopy (SEM. The properties of the monolithic column, such as permeability, binding capacity, and pore size distribution were also characterized in detail. From the results of the characterization of all monolith variation, monolith with %T 30 %C 50 and %T 35 %C 50 give the best characteristic. These monoliths have high permeability, adequate molecular recognition sites (represented with binding capacity value of over 20 mg/mL, and have over 80% flow through pores in their pore structure contribute to low flow resistance. The resulted monolithic columns have promising potential for dual mode liquid chromatography. MATE may contribute for anion-exchange while VBC may responsible for reversed-phase liquid chromatography.

  4. Deuterium isotopic effects connected with unimolecular and concerted mechanisms. The case of 1-deutero-2-chloro alcohols; Effets isotopiques du deuterium attaches a des mecanismes unimoleculaires et concertes. Cas des deutero-1-chloro-2 alcools

    Jambon, C

    1962-07-01

    After a bibliographic analysis of the probable causes of isotopic effects and their comparison, with the simplifications provided by the athermal model, a discussion of the isotopic effect of deuterium in organic molecules in terms of structural influences is presented, showing the important role of the C-D bond length which is shorter than the C-H bond length, and of the D atom's Van der Waals radius, shorter than that of the H atom. Kinetic measurements were carried out on some reactions involving the mechanisms proposed: unimolecular ionizations and halogen concentrates. The structural models chosen are: 2-chloro-cyclo-hexanols cis and trans 1-H and 2-D; 2-chloro-cyclo-pentanols cis trans 1-H and 1-D; 1-phenyl-l-chloro-2-propanol threo 2-H and 2-D. (author) [French] Apres une analyse bibliographique des causes probables d'effets isotopiques et leur comparaison, avec les simplifications qu'apporte le modele athermique, on a entrepris l'etude de la discussion isotopique du deuterium dans des molecules organiques en termes d'influences structurelles, cherchant a degager le role important de la longueur de la liaison C-D plus courte que C-H, et du rayon de Van der Waals de l'atome de D plus petit que celui de H. On a effectue des mesures cinetiques sur quelques reactions invoquant les mecanismes envisages: ionisations unimoleculaires et concentrees d'halogenes. Les modeles structuraux choisis sont: chloro 2 - cyclohexanols cis et trans H 1 et D 1; chloro 2 - cyclopentanols cis et trans H 1 et D 1; phenyl 1 - chloro 1 - propanol 2 threo H 2 et D 2. (auteur)

  5. Volatile sulphur compounds and pathways of L-methionine catabolism in Williopsis yeasts.

    Tan, Amelia W J; Lee, Pin-Rou; Seow, Yi-Xin; Ong, Peter K C; Liu, Shao-Quan

    2012-08-01

    Volatile sulphur compounds (VSCs) are important to the food industry due to their high potency and presence in many foods. This study assessed for the first time VSC production and pathways of L: -methionine catabolism in yeasts from the genus Williopsis with a view to understanding VSC formation and their potential flavour impact. Five strains of Williopsis saturnus (var. saturnus, var. subsufficiens, var. suavolens, var. sargentensis and var. mrakii) were screened for VSC production in a synthetic medium supplemented with L: -methionine. A diverse range of VSCs were produced including dimethyl disulphide, dimethyl trisulphide, 3-(methylthio)-1-propanal (methional), 3-(methylthio)-1-propanol (methionol), 3-(methylthio)-1-propene, 3-(methylthio)-1-propyl acetate, 3-(methylthio)-1-propanoic acid (methionic acid) and ethyl 3-(methylthio)-1-propanoate, though the production of these VSCs varied between yeast strains. W. saturnus var. saturnus NCYC22 was selected for further studies due to its relatively high VSC production. VSC production was characterised step-wise with yeast strain NCYC22 in coconut cream at different L: -methionine concentrations (0.00-0.20%) and under various inorganic sulphate (0.00-0.20%) and nitrogen (ammonia) supplementation (0.00-0.20%), respectively. Optimal VSC production was obtained with 0.1% of L: -methionine, while supplementation of sulphate had no significant effect. Nitrogen supplementation showed a dramatic inhibitory effect on VSC production. Based on the production of VSCs, the study suggests that the Ehrlich pathway of L: -methionine catabolism is operative in W. saturnus yeasts and can be manipulated by adjusting certain nutrient parameters to control VSC production. PMID:22370952

  6. Effect of the temperature on the physical properties of pure 1-propyl 3-methylimidazolium bis(trifluoromethylsulfonyl)imide and characterization of its binary mixtures with alcohols

    Highlights: ► The temperature dependence of the physical properties of [PMim][NTf2] was studied. ► Physical properties of its binary mixtures with alcohols were determined at 298.15 K. ► The thermal expansion coefficient of the pure ionic liquid was calculated. ► The heat capacity of the pure ionic liquid at 298.15 K was determined. ► The excess properties of binary mixtures were adjusted with Redlich–Kister equation. - Abstract: In this paper, physical properties of a high purity sample of the ionic liquid 1-propyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [PMim][NTf2], and its binary mixtures with methanol, ethanol, 1-propanol, and 2-propanol were measured at atmospheric pressure. The temperature dependence of density, refractive index and speed of sound (293.15 to 343.15) K and dynamic viscosity (298.15 to 343.15) K were studied at atmospheric pressure by conventional techniques for the pure ionic liquid. For its mixtures with alcohols, density, speed of sound, and refractive index were measured at T = 298.15 K over the whole composition range. The thermal expansion coefficient of the [PMim][NTf2] was calculated from the experimental results using an empirical equation, and values of the excess molar volume, excess refractive index, and excess molar isentropic compressibility for the binary systems at the above mentioned temperature, were calculated and fitted to the Redlich–Kister equation. The heat capacity of the pure ionic liquid at T = 298.15 K was determined using DSC.

  7. The same microbiota and a potentially discriminant metabolome in the saliva of omnivore, ovo-lacto-vegetarian and Vegan individuals.

    Francesca De Filippis

    Full Text Available The salivary microbiota has been linked to both oral and non-oral diseases. Scant knowledge is available on the effect of environmental factors such as long-term dietary choices on the salivary microbiota and metabolome. This study analyzed the microbial diversity and metabolomic profiles of the saliva of 161 healthy individuals who followed an omnivore or ovo-lacto-vegetarian or vegan diet. A large core microbiota was identified, including 12 bacterial genera, found in >98% of the individuals. The subjects could be stratified into three "salivary types" that differed on the basis of the relative abundance of the core genera Prevotella, Streptococcus/Gemella and Fusobacterium/Neisseria. Statistical analysis indicated no effect of dietary habit on the salivary microbiota. Phylogenetic beta-diversity analysis consistently showed no differences between omnivore, ovo-lacto-vegetarian and vegan individuals. Metabolomic profiling of saliva using (1H-NMR and GC-MS/SPME identified diet-related biomarkers that enabled a significant discrimination between the 3 groups of individuals on the basis of their diet. Formate, urea, uridine and 5-methyl-3-hexanone could discriminate samples from omnivores, whereas 1-propanol, hexanoic acid and proline were characteristic of non-omnivore diets. Although the salivary metabolome can be discriminating for diet, the microbiota has a remarkable inter-individual stability and did not vary with dietary habits. Microbial homeostasis might be perturbed with sub-standard oral hygiene or other environmental factors, but there is no current indication that a choice of an omnivore, ovo-lacto-vegetarian or vegan diet can lead to a specific composition of the oral microbiota with consequences on the oral homeostasis.

  8. Picosecond spectral relaxation of curcumin excited state in toluene–alcohol mixtures

    Excited state photophysics of Curcumin in a binary solvent mixture of toluene and five different alcohols (Methanol, Ethanol, 1-Propanol, 1-Butanol and 1-Octanol) are compared with an instrument time resolution of ∼40 ps. As the alcohol mole-fraction is varied from zero to unity, the observed trends in the fluorescence quantum yield and lifetime of the pigment in toluene–alcohol mixtures changes significantly in going from Methanol to 1-Octanol. This is attributed to the different degree of modulation of the non-radiative rates associated with the excited state intermolecular H bonding between the pigment and the alcohol. Fluorescence decays taken at the red edge of the emission spectrum started to show measurable rise times (200–30 ps) the magnitude of which decreased gradually with increasing alcohol mole-fraction. As a consequence the solvation times in the binary mixture were observed to slow down considerably at certain solvent compositions compared to that in neat alcohol. However, in toluene-1-Octanol mixture, the rise times and corresponding solvation times did not show a dependence on the 1-Octanol mole-fraction. The observed results suggest that viscosity, polarity and hydrogen bonding property of the alcohol solvent plays an important role in the excited state processes of the pigment in toluene–alcohol mixture. -- Highlights: • Excited state photophysics of Curcumin in a binary solvent mixture of toluene and five different alcohols were studied. • The observed trends in the fluorescence properties are attributed to intermolecular H bonding between the pigment and the alcohol. • Except 1-Octanol, the average solvation times of the pigment were observed to depend upon alcohol mole-fraction. • Viscosity, polarity and hydrogen bonding play an important role in the excited state processes of the pigment

  9. Measurement of nitrosamine and nitramine formation from NOx reactions with amines during amine-based carbon dioxide capture for postcombustion carbon sequestration.

    Dai, Ning; Shah, Amisha D; Hu, Lanhua; Plewa, Michael J; McKague, Bruce; Mitch, William A

    2012-09-01

    With years of full-scale experience for precombustion CO(2) capture, amine-based technologies are emerging as the prime contender for postcombustion CO(2) capture. However, concerns for postcombustion applications have focused on the possible contamination of air or drinking water supplies downwind by potentially carcinogenic N-nitrosamines and N-nitramines released following their formation by NO(x) reactions with amines within the capture unit. Analytical methods for N-nitrosamines in drinking waters were adapted to measure specific N-nitrosamines and N-nitramines and total N-nitrosamines in solvent and washwater samples. The high levels of amines, aldehydes, and nitrite in these samples presented a risk for the artifactual formation of N-nitrosamines during sample storage or analysis. Application of a 30-fold molar excess of sulfamic acid to nitrite at pH 2 destroyed nitrite with no significant risk of artifactual nitrosation of amines. Analysis of aqueous morpholine solutions purged with different gas-phase NO and NO(2) concentrations indicated that N-nitrosamine formation generally exceeds N-nitramine formation. The total N-nitrosamine formation rate was at least an order of magnitude higher for the secondary amine piperazine (PZ) than for the primary amines 2-amino-2-methyl-1-propanol (AMP) and monoethanolamine (MEA) and the tertiary amine methyldiethanolamine (MDEA). Analysis of pilot washwater samples indicated a 59 μM total N-nitrosamine concentration for a system operated with a 25% AMP/15% PZ solvent, but only 0.73 μM for a 35% MEA solvent. Unfortunately, a greater fraction of the total N-nitrosamine signal was uncharacterized for the MEA-associated washwater. At a 0.73 μM total N-nitrosamine concentration, a ~25000-fold reduction in concentration is needed between washwater units and downwind drinking water supplies to meet proposed permit limits. PMID:22831707

  10. Steam generator of Vandellos nuclear power station: Operational experience

    The Central Nuclear de Vandellos power station at Hospitalet del Infante, Spain, is a 500 MWe gas graphite moderated natural uranium reactor. The plant has generated over 46,000 million KWh over the past thirteen years of service. Throughout this service, the plant has suffered from THO phase erosion-corrosion damage in the steam generator sections of the system. The Vandellos steam generators are once-through units constructed of 1386 mild steel tubing (panels) each fabricated into a serpentine containing 83 horizontal passes. Four independent steam generator circuits are combined to feed two, 250 MWe turbines. Erosion-corrosion damage has caused panel element leakage in the evaporation of some tubing elements. The rate of erosion-corrosion damage has been modified through different operational changes since damage was first detected in 1975. This paper describes the different operating behavior of the four steam generators and an evaluation of damage through the expertise of different technical resource groups. The changes in plant operating technique discussed include hydrodynamic conditions and chemical treatment parameters. One of the most important changes in plant operation has been in the use of amines as alkaline agents. Solutions of ammonia were initially used for pH control of feedwater. In an effort to reduce erosion-corrosion levels below rates experienced using ammonia, a change was made to the use of morpholine, and more recently, a change to the use of AMP(2 amino-2-methyl-1-propanol) has shown favorable results. The paper outlines the overall behavior of steam generator function under plant transition conditions, and contrasts that behavior with current chemical parameters experienced using AMP treatment. Water chemistry characteristics are used to present an evaluation of the development of erosion-corrosion damages from 1976 through present operating conditions. (author)

  11. Wetting transition and pretransitional thin films in binary liquids: alcohol/perfluoromethylcyclohexane mixtures studied by x-ray reflectivity

    In this study the wetting transition at the liquid-vapour interface of binary organic liquid mixtures has been investigated by x-ray reflectivity. Mixtures of various isomeric alcohols with perfluoromethylcyclohexane (PFMC) served as model systems, with alcohol carbon numbers ranging from 1 to 4. Remarkably different pretransitional behaviour of the thin films below the wetting temperature was observed, which could be classified according to the carbon number. At two-phase coexistence, no pretransitional thin films could be detected for methanol and ethanol, whereas thin-to-thick-film transitions were found for propanol and butanol and their isomers. For 1-propanol and 2-propanol, the surface of the upper, alcohol-rich phase of the gravity-separated mixture displays a wetting transition at Tw = 31.5 deg. C and 38.3 deg. C, respectively, where the thickness of a PFMC-rich film jumps from less than 25 A to values exceeding the experimental resolution of about 1200 A. For 1-butanol, 2-butanol and i-butanol, we found pretransitional film thicknesses increasing up to 100 A, with wetting transitions at Tw = 45.0 deg. C, 34.2 deg. C and 40.1 deg. C, respectively. In the single-phase region, the study of adsorption isotherms above Tw revealed novel behaviour of the adsorbed PFMC-rich film. We observed both a growing film thickness and a significantly changing composition as the coexistence line was approached. Nevertheless, the variation of the excess adsorption with distance from coexistence could still be described by a power law. (author)

  12. Antioxidation Properties and Surface Interactions of Polyvinylpyrrolidone-Capped Zerovalent Copper Nanoparticles Synthesized in Supercritical Water.

    Morioka, Takuya; Takesue, Masafumi; Hayashi, Hiromichi; Watanabe, Masaru; Smith, Richard L

    2016-01-27

    Zerovalent copper nanoparticles (CuNPs) (diameter, 26.5 ± 9 nm) capped with polyvinylpyrrolidone (PVP) were synthesized in supercritical water at 400 °C and 30 MPa with a continuous flow reactor. The PVP-capped CuNPs were dispersed in distilled water, methanol, ethanol, 1-propanol, 2-propanol, butanol, and their mixed solvents to study their long-term stability. Temporal variation of UV-vis spectra and surface plasmon resonance were measured and showed that ethanol, the propanols, and butanol solvents provided varying degrees of oxidative protection for Cu(0). Fourier transform infrared spectroscopy showed that PVP adsorbed onto the surface of the CuNPs with a pyrrolidone ring of PVP even if the CuNPs were oxidized. Intrinsic viscosities of PVP were higher for solvents that provided antioxidation protection than those that give oxidized CuNPs. In solvents that provided Cu(0) with good oxidative protection (ethanol, the propanols, and butanol), PVP polymer chains formed large radii of gyration and coil-like conformations in the solvents so that they were arranged uniformly and orderly on the surface of the CuNPs and could provide protection of the Cu(0) surface against dissolved oxygen. In solvents that provided poor oxidative protection for Cu(0) (water, alcohol-water mixed solvents with 30% water), PVP polymer chains had globular-like conformations due to their relatively high hydrogen-bonding interactions and sparse adsorption onto the CuNP surface. Antioxidative properties of PVP-capped CuNPs in a solvent can be ascribed to the conformation of PVP polymer chains on the Cu(0) particle surface that originates from the interaction between polymer chains and its interaction with the solvent. PMID:26716468

  13. Synthesis of Biodiesel from the Oily Content of Marine Green Alga Ulva fasciata

    The present study is focused on the chemical transformation of oils derived from the marine green alga Ulva fasciata Delile to biodiesel. The transesterification of algal oil was performed with a variety of alcohols using Na metal and NaOH as catalysts. Transesterification of algal oil by mechanical stirring yielded significant biodiesel within an hour at 60 degree C with NaOH and at room temperature with Na metal. In addition, microwave irradiated transesterification produced significant amount of biodiesel with NaOH and Na metal within 1-5 minutes. However, reaction of sodium metal in microwave oven was highly exothermic and uncontrollable that could also damage the radiation source. The reactivity order of alcohols was found to be methanol > ethanol > benzyl alcohol > 1-propanol > 1-butanol > 1-pentanol > 1-hexanol > 2-propanol. Isopropyl alcohol was found to be least reactive due to steric hindrance. Benzyl alcohol was found to be more reactive than 1-propyl alcohol due to the electron withdrawing effect of benzene ring. The highest % conversion of FAME and FAEE were found to be 97% and 98% respectively using Na metal through mechanical stirring. Biodiesel production was confirmed by thin layer chromatography (TLC). Furthermore, the fuel properties including density, kinematics viscosity, high heating value, acid value, free fatty acid (%), cloud point and pour point of U. fasciata oil and all the esters were determined and compared with the standard limits of biodiesel. Fatty acid methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 1-pentyl and 1-hexyl esters showed the fuel properties within the biodiesel standard limits therefore all of them were considered as the substitute of biodiesel. On the other hand, the fuel properties of benzyl ester were found to be above the limits of biodiesel specifications and thus it could not be considered as biodiesel. This research article will be helpful to overcome the current challenges of energy crisis, global warming and

  14. Excited state charge transfer reaction in (mixed solvent + electrolyte) systems: Role of reactant-solvent and reactant-ion interactions

    Harun Al Rasid Gazi; Ranjit Biswas

    2011-05-01

    Fluorescence spectroscopic techniques have been used to study the excited state intramolecular charge transfer reaction of 4-(1-azetidinyl)benzonitrile (P4C) in two sets of mixed solvents, (1-propanol + ethyl acetate) and (propylene carbonate + acetonitrile), in the absence and presence of a strong electrolyte, lithium perchlorate. These two sets of mixed solvent systems represent binary solvent mixtures of low and high polarities, respectively. Density, sound velocity and viscosity measurements indicate that these two mixed solvent systems are structurally different. Stronger ion-reactant interaction is evidenced in the mole fraction independence of emission frequencies in electrolyte solutions of low polar binary solvent mixtures. For both these mixtures, the reaction driving force (- ) decreases with increase in mole fraction of the relatively less polar solvent component of the mixture. Interestingly, - increases significantly on addition of electrolyte in low polar mixtures and exhibits mixture composition dependence but, in contrast, - in high polar mixtures does not sense variation in mixture composition in presence of electrolyte. This insensitivity to mixture composition for high polar mixtures is also observed for the measured reaction time constant. In addition, the reaction time constant does not sense the presence of electrolyte in the high polar solvent mixtures. The reaction time constant in low polar mixtures, which becomes faster on addition of electrolyte, lengthens on increasing the mole fraction of the relatively less polar solvent component of the mixture. These observations have been qualitatively explained in terms of the measured solvent reorganization energy and reaction driving force by using expressions from the classical theory of electron transfer reaction.

  15. Metabolism of L-methionine linked to the biosynthesis of volatile organic sulfur-containing compounds during the submerged fermentation of Tuber melanosporum.

    Liu, Rui-Sang; Zhou, Huan; Li, Hong-Mei; Yuan, Zhan-Peng; Chen, Tao; Tang, Ya-Jie

    2013-12-01

    Tuber melanosporum, known as the black diamond of cuisine, is highly appreciated for its unique and characteristic aroma, which is mainly due to its volatile organic sulfur-containing compounds (VOSCs). In this work, by adding 5 g/L L-methionine to the fermentation medium, the activities of aminotransferase and α-ketoacid decarboxylase were significantly enhanced by 103 and 250%, respectively, while the activities of alcohol dehydrogenase and demethiolase were decreased by 277 and 39%. Then, the six VOSCs, i.e., methanethiol (MTL), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), 3-(methylthio)propanal (methional), and 3-(methylthio)-1-propanol (methionol), were first detected in the submerged fermentation of T. melanosporum. These results indicated that the biosynthesis of VOSCs was triggered by aminotransferase and α-ketoacid decarboxylase. The production of methional and methionol increased with the increased concentrations of L-methionine (i.e., 5, 10, 15, and 20 g/L) before day 4 of the culture protocol, and methionol was the major product in the Ehrlich pathway. The production of MTL was significantly decreased after day 4 with a significantly increased DMDS, and DMDS was the major product of the demethiolation pathway. Compared with the demethiolation pathway with a total flux of sulfur of 11.33-24.32 μM, the Ehrlich pathway with a total flux of sulfur of 6,149-10,330 μM was considered the major pathway for the biosynthesis of VOSCs. This is the first report linking the metabolism of L-methionine to the biosynthesis of VOSCs by the Ehrlich and demethiolation pathways during the submerged fermentation of T. melanosporum. PMID:24092005

  16. A combined experimental and computational investigation of excess molar enthalpies of (nitrobenzene + alkanol) mixtures

    Highlights: • Excess molar enthalpies for the binary mixtures of nitrobenzene + alkanols mixtures were measured. • The infinite dilution excess partial molar enthalpies were calculated using the ab initio methods. • The PCM calculations were performed. • The computed excess partial molar enthalpies at infinite dilution were compared to experimental results. - Abstract: Excess molar enthalpies (HmE) for the binary mixtures of {(nitrobenzene + ethanol), 1-propanol, 2-propanol, 1-butanol and 2-butanol} have been measured over the entire composition range at ambient pressure (81.5 kPa) and temperature 298 K using a Parr 1455 solution calorimeter. From the experimental results, the excess partial molar enthalpies (HiE) and excess partial molar enthalpies at infinite dilution (HiE,∞) were calculated. The excess molar enthalpies (HmE) are positive for all {nitrobenzene (1) + alkanol (2)} mixtures over the entire composition range. A state-of-the-art computational strategy for the evaluation of excess partial molar enthalpies at infinite dilution was followed at the M05-2X/6-311++G∗∗ level of theory with the PCM model. The experimental excess partial molar enthalpies at infinite dilution have been compared to the computational data of the ab initio in liquid phase. Integrated experimental and computational results help to clarify the nature of the intermolecular interactions in {nitrobenzene (1) + alkanol (2)} mixtures. The experimental and computational work which was done in this study complements and extends the general research on the computation of excess partial molar enthalpy at infinite dilution of binary mixtures

  17. Radiation sterilization of ephedrine in the solid state

    The effects of the e-beam ionising radiation of energy 9.96 MeV in doses 25-800 kGy on the stability of solid ephedrine hydrochloride (1R,2S)-(-)-2-methylamino-1-phenyl-1-propanol hydrochloride) have been studied. These effects have been observed using the following analytical methods: organoleptic (form, colour, smell, clarity of solution), scanning electron microscope SEM, pH measurement, chirality and water content measurement (Karl Fischer method), spectrometric methods (UV, FT-IR, EPR), chromatography (TLC), and combined chromatography (TLC-UV, GC-MS). Even the standard sterilisation dose of 25 kGy has been found to cause a change in colour from white to pale yellow, the appearance of free radicals in the concentration of 3.05 x 1015 spin g-1, and about 1% loss of the content. The effects of higher doses 50-800 kGy have shown that radiodegradation degree of the compound is proportional to the dose applied. The main product of radiodegradation, formed at a yield of G = 17.17 x 10-7 mol J-1, has been identified as 2-methylamino-1 phenyl-1-propanone (methcathinone, ephedrone), a psychoactive compound of the activity similar to that of amphetamine. For the above reasons ephedrine hydrochloride can not be subjected to radiative sterilisation with a dose of 25 kGy, however, assuming sufficiently low microbiological contamination of the initial substance, lower doses could be probably used for sterilisation purposes. Our results have not confirmed the earlier reports from 1970s on the resistance of ephedrine to ionising radiation in doses up to 60 kGy. (authors)

  18. Preparation of a polymeric ionic liquid-based adsorbent for stir cake sorptive extraction of preservatives in orange juices and tea drinks.

    Chen, Lei; Huang, Xiaojia

    2016-04-15

    In this study, a new polymeric ionic liquid-based adsorbent was prepared and used as the extraction medium of stir cake sorptive extraction (SCSE) of three organic acid preservatives, namely, p-hydroxybenzoic acid, sorbic acid and cinnamic acid. The adsorbent was synthesized by the copolymerization of 1-ally-3-vinylimidazolium chloride (AV) and divinylbenzene (DVB) in the presence of a porogen solvent containing 1-propanol and 1,4-butanediol. The effect of the content of monomer and the porogen solvent in the polymerization mixture on the extraction performance was investigated thoroughly. The adsorbent was characterized by infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. To obtain the optimal extraction conditions of SCSE/AVDVB for target analytes, key parameters including desorption solvent, adsorption and desorption time, ionic strength and pH value in sample matrix were studied in detail. The results showed that under the optimized conditions, the SCSE/AVDVB could extract the preservatives effectively through multiply interactions. At the same time, a simple and sensitive method by combining SCSE/AVDVB and high-performance liquid chromatography with diode array detection was developed for the simultaneous analysis of the target preservatives in orange juices and tea drinks. Low limits of detection (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target analytes were achieved within the range of 0.012-0.23 μg/L and 0.039-0.42 μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as relative standard deviation (RSD), and it was found that the values were all below 10%. Finally, the proposed method was used to detect preservatives in different orange juice and tea drink samples successfully. The recoveries were in the range of 71.9-116%, and the RSDs were below 10% in the all cases. PMID:27016436

  19. Development and characterization of dilutable self-microemulsifying premicroemulsion systems (SMEPMS as templates for preparation of nanosized particulates

    Lin SF

    2013-09-01

    Full Text Available Shen-Fu Lin,1 Ying-Chen Chen,2 Hsiu-O Ho,2 Wei-Yu Huang,2 Ming-Thau Sheu,2,3 Der-Zen Liu1,4 1Graduate Institute of Biomedical Materials and Tissue Engineering, College of Oral Medicine, 2School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan; 3Clinical Research Center and Traditional Herbal Medicine Research Center, Taipei Medical University Hospital, Taipei, Taiwan; 4Center for General Education, Hsuan Chuang University, Hsinchu, Taiwan Abstract: The utilization of self-microemulsifying premicroemulsion systems (SMEPMS as templates for preparing poorly water-soluble compounds in the nanosized range represents a promising strategy. Fenofibrate was formulated with n-butyl L-lactate, Tween 80, and a number of cosurfactants (ethanol, 1-propanol, and PEG 600, diluted with the water phase (either water or saccharide solution and then subjected to a freeze-drying (FD process to obtain SMEPMS nanosized particulates. Results demonstrated that the particle size after resuspension of these FD SMEPMS nanosized particulates in water was too large, so the addition of saccharide solutions (lactose, mannitol, glucose, sucrose, and trehalose as the solid carrier to prevent particles from aggregating seemed to be necessary and workable due to steric hindrance and repulsion. However, instability of these resuspended FD nanosized particulates after 30–90 minutes still occurred, and the addition of 0.5% sodium lauryl sulfate in the resuspending medium was able to retard the aggregation and maintain the particle size within the nano-range. Evaluation by scanning electron microscopy and X-ray powder diffraction also confirmed the results. It was concluded that using an SMEPMS formulation with PEG 600 as the cosurfactant, and in the presence of a suitable saccharide as an anticaking agent and FD process were able to produce fenofibrate nanoparticles. Keywords: fenofibrate, saccharides, freeze-drying, nanoparticles

  20. Properties of pure 1,1,3,3-tetramethylguanidine imidazole ionic liquid and its binary mixtures with alcohols at T = (293.15 to 313.15) K

    Highlights: • Densities and viscosities of [TMG]IM + alcohol mixtures were measured. • Coefficient of thermal expansion, molecular volume, standard entropy, and lattice energy were obtained. • Excess molar volumes and viscosity deviations were calculated and fitted to Redlich–Kister equation. • Other volumetric properties and excess Gibbs free energy of activation for viscous flow were deduced. • The intermolecular interactions between [TMG]IM and alcohols were analyzed. - Abstract: Densities and viscosities of the pure ionic liquid 1,1,3,3-tetramethylguanidine imidazole ([TMG]IM) and its binary mixtures with methanol, ethanol, 1-propanol, and 1-butanol were measured at temperatures from T = (293.15 to 313.15) K. The thermal expansion coefficient, molecular volume, standard entropy, and lattice energy of [TMG]IM were obtained from the experimental density value. The temperature dependence of the viscosity of [TMG]IM was fitted to the fluidity equation. Excess molar volumes VE and viscosity deviations Δη of the binary mixtures were calculated and fitted to the Redlich–Kister equation with satisfactory results. The result shows that the VE values of the binary mixtures are negative over the whole composition range, while Δη values have an S-shape deviation. Temperature has little effect on the VE of the systems, but it has significant effect on the Δη. Furthermore, the absolute values of VE for {[TMG]IM (1) + alcohol (2)} systems at the same temperature decrease with increasing carbon alkyl chain of the primary alcohol. Other derived properties, such as the apparent molar volumes, partial molar volumes, excess partial molar volumes, Gibbs free energy of activation for viscous flow, and excess Gibbs free energy of activation for viscous flow of the above-mentioned systems were also calculated

  1. Effects of new Torulaspora delbrueckii killer yeasts on the must fermentation kinetics and aroma compounds of white table wine

    Rocío eVelázquez

    2015-11-01

    Full Text Available Torulaspora delbrueckii is becoming widely recommended for improving some specific characteristics of wines. However, its impact on wine quality is still far from satisfactory at the winery level, mostly because it is easily replaced by S. cerevisiae-like yeasts during must fermentation. New T. delbrueckii killer strains were here isolated and selected for winemaking. They killed S. cerevisiae yeasts and were able to dominate and complete the fermentation of sterile grape must. Sequential yeast inoculation of non-sterile white must with T. delbrueckii followed by S. cerevisiae did not ensure T. delbrueckii dominance or wine quality improvement. Only a single initial must inoculation at high cell concentrations allowed the T. delbrueckii killer strains to dominate and complete the must fermentation to reach above 11% ethanol, but not the non-killer strains. None of the wines underwent malolactic fermentation as long as the must had low turbidity and pH. Although no statistically significant differences were found in the wine quality score, the S. cerevisiae-dominated wines were preferred over the T. delbrueckii-dominated ones because the former had high-intensity fresh fruit aromas while the latter had lower intensity, but nevertheless nice and unusual dried fruit/pastry aromas. Except for ethyl propanoate and 3-ethoxy-1-propanol, which were more abundant in the T. delbrueckii–dominated wines, most of the compounds with fresh fruit odour descriptors, including those with the greatest odour activity values (isoamyl acetate, ethyl hexanoate, and ethyl octanoate, were more abundant in the S. cerevisiae–dominated wines. The low relative concentrations of these fruity compounds made it possible to detect in the T. delbrueckii–dominated wines the low-relative-concentration compounds with dried fruit and pastry odours. An example was γ-ethoxy-butyrolactone which was significantly more abundant in these wines than in those dominated by S

  2. Supporting technology for the development of Controlled Ecological Life Support Systems (CELSS)

    Li, Ku-Yen; Yaws, Carl L.; Simon, William E.; Mei, Harry T.

    1995-01-01

    To support the development of Controlled Ecological Life Support Systems (CELSS) in the space program, a metabolic simulator has been selected for use in a closed chamber to test functions of the CELSS. This metabolic simulator is a catalytic reactor which oxidizes the methyl acetate to produce carbon dioxide and water vapor. In this project, kinetic studies of catalytic oxidation of methyl acetate were conducted using monolithic and pellet catalysts with 0.5% (by weight) platinum (Pt) on aluminum oxide (Al2O3). The reaction was studied at a pressure of one atmosphere and at temperatures varying from 160 C to 420 C. By-products were identified at the exit of the preheater and reactor. For the kinetic study with the monolithic catalyst, a linear regression method was used to correlate the kinetic data with zero-order, first-order and Langmuir-Hinshelwood models. Results indicate that the first-order model represents the data adequately at low concentrations of methyl acetate. For higher concentrations of methyl acetate, the Langmuir-Hinshelwood model best represents the kinetic data. Both rate constant and adsorption equilibrium constants were estimated from the regression. A Taguchi orthogonal array (L(sub 9)) was used to investigate the effects of temperature, flow rate, and concentration on the catalytic oxidation of methyl acetate. For the monolithic catalyst, temperature exerts the most significant effect, followed by concentration of methyl acetate. For the pellet catalyst, reaction temperature is the most significant factor, followed by gas flow rate and methyl acetate concentration. Concentrations of either carbon dioxide or oxygen were seen to have insignificant effect on the methyl acetate conversion process. Experimental results indicate that the preheater with glass beads can accomplish thermal cracking and catalytic reaction of methyl acetate to produce acetic acid, methanol, methyl formate, and 1-propanol. The concentration of all by-products was

  3. Regulation of SREBPs by Sphingomyelin in Adipocytes via a Caveolin and Ras-ERK-MAPK-CREB Signaling Pathway.

    Nehman Makdissy

    Full Text Available Sterol response element binding protein (SREBP is a key transcription factor in insulin and glucose metabolism. We previously demonstrated that elevated levels of membrane sphingomyelin (SM were related to peroxisome proliferator-activated receptor-γ (PPARγ, which is a known target gene of SREBP-1 in adipocytes. However, the role of SM in SREBP expression in adipocytes remains unknown. In human abdominal adipose tissue from obese women with various concentrations of fasting plasma insulin, SREBP-1 proteins decreased in parallel with increases in membrane SM levels. An inverse correlation was found between the membrane SM content and the levels of SREBP-1c/ERK/Ras/PPARγ/CREB proteins. For the first time, we demonstrate the effects of SM and its signaling pathway in 3T3-F442A adipocytes. These cells were enriched or unenriched with SM in a range of concentrations similar to those observed in obese subjects by adding exogenous natural SMs (having different acyl chain lengths or by inhibiting neutral sphingomyelinase. SM accumulated in caveolae of the plasma membrane within 24 h and then in the intracellular space. SM enrichment decreased SREBP-1 through the inhibition of extracellular signal-regulated protein kinase (ERK but not JNK or p38 mitogen-activated protein kinase (MAPK. Ras/Raf-1/MEK1/2 and KSR proteins, which are upstream mediators of ERK, were down-regulated, whereas SREBP-2/caveolin and cholesterol were up-regulated. In SM-unmodulated adipocytes treated with DL-1-Phenyl-2-Palmitoylamino-3-morpholino-1-propanol (PPMP, where the ceramide level increased, the expression levels of SREBPs and ERK were modulated in an opposite direction relative to the SM-enriched cells. SM inhibited the insulin-induced expression of SREBP-1. Rosiglitazone, which is an anti-diabetic agent and potent activator of PPARγ, reversed the effects of SM on SREBP-1, PPARγ and CREB. Taken together, these findings provide novel insights indicating that excess

  4. The effect of thiolated additives on the properties of wheat gluten based plastics, aqueous solutions and electrospun fibers

    Dong, Jing

    Wheat gluten (WG) is a promising substitute for petroleum-based plastics due to its unique ability to form a cohesive blend with viscoelastic properties once plasticized. Previous work blending WG with thiolated poly(vinyl alcohol) (TPVA) showed that both the strength and elongation of compression molded native WG bars can be improved via thiol/disulfide interchange reactions between WG and TPVA. In this study, the morphology of WG/TPVA blends was investigated by atomic force (AFM) and transmission electron microscopy (TEM), as well as by modulated dynamic scanning calorimetry (MDSC). Consistent with our earlier results, AFM and TEM imaging clearly indicated that TPVA is much more compatible with WG compared with poly(vinyl alcohol) (PVA) although there are still two phases in the blend: one WG rich phase and another TPVA rich phase. TPVA was also blended with WG in an aqueous solvent (1/1 (v/v) water/1-propanol mixture) to improve its solubility and spinnability. Control experiments were conducted with PVA and dithiothreitol (DTT) for comparison purposes. The concentration and the thiolation level of TPVA were also varied to explore the parameter space. The interactions of thiol groups from TPVA and soluble WG were found to be important during electrospinning. The fiber diameter became more uniform and the fiber quality increased very noticeably when TPVA was included. Furthermore, the time-dependent rheology behaviors of TPVA/WG and DTT/WG electrospinning solutions were investigated by using steady shear sweeps, oscillatory frequency sweeps, SE-HPLC and free -SH content determination. A two-step mechanism of interaction was proposed for DTT/WG and TPVA/WG solutions based on current results and other earlier studies. In comparison with WG and PVA/WG solutions, the reduction and reformation of disulfide linkages in both TPVA/WG and DTT/WG solutions were believed to play a key role in determining the rheological properties and molecular weight distribution of WG

  5. Isolation of radioactive strontium from natural samples. Separation of strontium from alkaline and alkaline earth elements by means of mixed solvent anion exchange

    This paper presents the results of studies which led to the procedures for the chromatographic separation of radioactive strontium from alkaline, earth-alkaline and other elements in natural samples, on columns filled with strong base anion exchangers using alcoholic solutions of nitric acid as eluents. It has been shown that potassium, caesium, calcium, barium, yttrium and strontium can be adsorbed on strong base anion exchangers of the Dowex and Amberlite type, which contain the quaternary ammonium group with nitrate as counter-ion, from solutions of nitric acid in alcohol. Adsorption strength increases in the order methanol 3 in methanol, while they are adsorbed from ethanol and propanol. The adsorption strength is influenced by the polarity of alcohol, by the concentration of nitrate and by pH. The strength with which strontium adsorbs on the exchangers increases in the interval from 0 to 0.25M NH4NO3 in methanol, after which it starts to decrease. Strontium adsorbs to the exchangers from the alcoholic solution of ammonium nitrate twice as strongly as from the alcoholic solution of nitric acid, while a fraction of water in pure alcohol exceeding 10% prevents adsorption. In the mixture of alcohol and nitric acid, the adsorption strength for calcium and strontium increases with the increase of the volume fraction of alcohol with a lower dielectric constant. The rate and strength of adsorption of ions on the exchanger also increase in the series 0.25M HNO3 in methanol 3 in ethanol 3 in 1-propanol for each individual ion, as well as in the Ca3 in methanol, 0.25M HNO3 in ethanol and 0.25M HNO3 in propanol. Separation is also possible from alcohol mixtures. Strontium separation is most difficult from calcium, while the efficiency of separation increases with a decrease of the polarity of the used alcohol or alcohol mixture. The first group elements of the periodic table are not separated from each other in this way, while the elements of the second group are

  6. Development of Sulfonated FEP / Nafion Hybrid Proton Exchange Membranes for PEFC

    Membrane Electrode Assemblies (MEAs) in polymer electrolyte fuel cells (PEFCs) are consisted of proton exchange membranes (PEMs), binder and Pt/C electrodes. In our previous work, the partial-fluorinated sulfonic acid membranes have been fabricated by pre EB-grafting method. However, in the PEFC operation at higher temperatures, the difference of thermo-physical properties in MEAs consists of obtained PEMs, Pt/C, electrodes and binder such as Nafion-dispersion would be induced de-lamination between the PEM and electrodes. The poor adhesion between PEM and electrodes causes higher membrane resistance and decreasing of PEFC performance. In this study, in order to get well-laminated MEA, PEMs based on partial-fluorinated sulfonic acid were fabricated by adding same polymeric components with binder materials. Fluorinated ethylene-propylene co-polymer (FEP) films (thickness: 25μm) were grafted with styrene monomer at 80 degree in liquid phase after EB irradiation under nitrogen gas atmosphere at room temperature, and then sulfonated by chlorosulfonic acid solution. The sulfonated FEP membranes (s-FEP) were milled to fine powders and the average diameter was 73.6μm. Then, s-FEP / Nafion hybrid membranes (FN) were obtained by mixing s-FEP powder with Nafion-dispersion and 1-propanol. The thickness of obtained FN was about 90μm. Ion exchange capacity (IEC) was measured by titration. IECs of FN and Nafion were 1.2 meq/g and 0.9 meq/g, respectively. MEA was fabricated by hot-pressing, and was measured by electrochemical spectroscopy. PEFC performances at 60 degree of FN, Nafion 112 and s-FEP were evaluated. The power density of FN at 500 mA/cm2 and the maximum power density were about 1.1 times higher than those of Nafion 112, respectively.The membrane resistance and ion conductivity (IC) of MEAs were measured by 4-electrode AC impedance method. Ohmic resistance and charge transfer resistance of FN were lower than those of s-FEP. These indicate that interface properties

  7. Photochemical ozone creation potentials for oxygenated volatile organic compounds: sensitivity to variations in kinetic and mechanistic parameters

    Jenkin, Michael E.; Hayman, Garry D.

    The sensitivity of Photochemical Ozone Creation Potentials (POCP) to a series of systematic variations in the rates and products of reactions of radical intermediates and oxygenated products is investigated for the C 4 alcohols, 1-butanol ( n-butanol) and 2-methyl-1-propanol ( i-butanol), using the recently developed Master Chemical Mechanism (MCM) as the base case. The POCP values are determined from the calculated formation of ozone in the boundary layer over a period of approximately five days along an idealised straight line trajectory, using a photochemical trajectory model and methodology described in detail previously. The results allow the relative impacts on calculated ozone formation of various classes of chemical reaction within the degradation chemistry to be assessed. The calculated POCP is found to be very insensitive to many of the changes investigated. However, it is found to be sensitive to variations in the rate coefficient for the initiating reaction with OH ( kOH), although the sensitivity decreases with increasing kOH. The POCP appears to vary approximately linearly with kOH at low values (i.e. kOH less than ca. 4×10 -13 cm 3 molecule -1 s -1), whereas at high reactivities (i.e. kOH greater than ca. 4×10 -11 cm 3 molecule -1 s -1), the calculated POCP value is comparatively insensitive to the precise value of kOH. The POCP is also very sensitive to mechanistic changes which influence the yields of unreactive oxygenated products (i.e. those with OH reactivities below ca. 10 -12 cm 3 molecule -1 s -1), for example acetone. The propensity of the organic compound to produce organic nitrates (which act as comparatively unreactive reservoirs for free radicals and NO x) also appears to have a notable influence on the calculated POCP. Recently reported information relevant to the degradation of oxygenated VOCs is then used to update the chemical schemes for the 17 alcohols and glycols, 10 ethers and glycol ethers, and 8 esters included in the MCM

  8. Facile synthesis of new nano sorbent for magnetic solid-phase extraction by self assembling of bis-(2,4,4-trimethyl pentyl)-dithiophosphinic acid on Fe{sub 3}O{sub 4}-Ag core-shell nanoparticles: Characterization and application

    Tahmasebi, Elham [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Yamini, Yadollah, E-mail: yyamini@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of)

    2012-12-05

    Graphical abstract: Self assembling of bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid on Fe{sub 3}O{sub 4}-Ag core-shell nanoparticles and application of it for solid phase extraction of PAHs. Highlights: Black-Right-Pointing-Pointer A novel sorbent for magnetic solid-phase extraction of PAHs was introduced. Black-Right-Pointing-Pointer Silver was coated on Fe{sub 3}O{sub 4} nanoparticles (MNPs) by reduction of AgNO{sub 3} with NaBH{sub 4}. Black-Right-Pointing-Pointer Bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid self-assembled on silver coated MNPs. Black-Right-Pointing-Pointer Size, morphology, composition and properties of the nanoparticles were characterized. Black-Right-Pointing-Pointer Extraction efficiency of the sorbent was investigated by extraction of five PAHs. - Abstract: A novel sorbent for magnetic solid-phase extraction by self-assembling of organosulfur compound, (bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid), onto the silver-coated Fe{sub 3}O{sub 4} nanoparticles was introduced. Due to the formation of covalent bond of S-Ag, the new coating on the silver surface was very stable and showed high thermal stability (up to 320 Degree-Sign C). The size, morphology, composition, and properties of the prepared nanoparticles have also been characterized and determined using scanning electron microscopy (SEM), energy-dispersive X-ray analyzer (EDX), dynamic light scattering (DLS), Fourier transform-infrared (FT-IR) spectroscopy, and thermal gravimetric analysis (TGA). Extraction efficiency of the new sorbent was investigated by extraction of five polycyclic aromatic hydrocarbons (PAHs) as model compounds. The optimum extraction conditions for PAHs were obtained as of extraction time, 20 min; 50 mg sorbent from 100 mL of the sample solution, and elution with 100 {mu}L of 1-propanol under fierce vortex for 2 min. Under the optimal conditions, the calibration curves were obtained in the range of 0.05-100 {mu}g L{sup -1} (R{sup 2} > 0.9980) and the

  9. Facile synthesis of new nano sorbent for magnetic solid-phase extraction by self assembling of bis-(2,4,4-trimethyl pentyl)-dithiophosphinic acid on Fe3O4-Ag core-shell nanoparticles: Characterization and application

    Graphical abstract: Self assembling of bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid on Fe3O4-Ag core-shell nanoparticles and application of it for solid phase extraction of PAHs. Highlights: ► A novel sorbent for magnetic solid-phase extraction of PAHs was introduced. ► Silver was coated on Fe3O4 nanoparticles (MNPs) by reduction of AgNO3 with NaBH4. ► Bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid self-assembled on silver coated MNPs. ► Size, morphology, composition and properties of the nanoparticles were characterized. ► Extraction efficiency of the sorbent was investigated by extraction of five PAHs. - Abstract: A novel sorbent for magnetic solid-phase extraction by self-assembling of organosulfur compound, (bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid), onto the silver-coated Fe3O4 nanoparticles was introduced. Due to the formation of covalent bond of S-Ag, the new coating on the silver surface was very stable and showed high thermal stability (up to 320 °C). The size, morphology, composition, and properties of the prepared nanoparticles have also been characterized and determined using scanning electron microscopy (SEM), energy-dispersive X-ray analyzer (EDX), dynamic light scattering (DLS), Fourier transform-infrared (FT-IR) spectroscopy, and thermal gravimetric analysis (TGA). Extraction efficiency of the new sorbent was investigated by extraction of five polycyclic aromatic hydrocarbons (PAHs) as model compounds. The optimum extraction conditions for PAHs were obtained as of extraction time, 20 min; 50 mg sorbent from 100 mL of the sample solution, and elution with 100 μL of 1-propanol under fierce vortex for 2 min. Under the optimal conditions, the calibration curves were obtained in the range of 0.05–100 μg L−1 (R2 > 0.9980) and the LODs (S/N = 3) were obtained in the range of 0.02–0.10 μg L−1. Relative standard deviations (RSDs) for intra- and inter-day precision were 2.6–4.2% and 3.6–8.3%, respectively. In

  10. Expression of verotoxin-1 receptor Gb3 in breast cancer tissue and verotoxin-1 signal transduction to apoptosis

    The prerequisite for the potential use of the bacterial toxin verotoxin-1 in the treatment of breast cancer was investigated by first determining the expression of its receptor Gb3 (CD77) in clinical breast cancer tissue specimens. We then examined the cytotoxicity and mechanism of apoptosis induction of Escherichia coli verotoxin-1 (VT-1) in two human breast cancer cell lines. Immunohistochemistry for Gb3 expression was performed on cryostat section from 25 breast cancer specimens. The human breast cancer cell lines T47D and MCF-7 were screened for Gb3 expression by flow cytometry. Fluorescein diacetate and LDH release was used to determine cell viability after VT-1 exposure. Apoptosis was studied by measuring caspase activity and DNA-fragmentation. Signal transduction studies were performed on T47D cells with immunoblotting. Gb3 expression was detected in the vascular endothelial cells of all tumours specimens, and in tumour cells in 17 of the specimens. We found no associations between tumour cell Gb3-expression and age, tumour size, TNM-classification, histological type, hormone receptor expression, or survival time. T47D cells strongly expressed Gb3 and were sensitive to the cytotoxicity, caspase activation and DNA fragmentation by VT-1, whereas MCF-7 cells with faint Gb3-expression were insensitive to VT-1. VT-1 (0.01 – 5 μg/L) exposure for 72 h resulted in a small percentage of viable T47D cells whereas the cytotoxicity of cells pre-treated with 2 μmol/L D, L-treo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (PPMP, an inhibitor of glucosylceramide synthesis) was eliminated (≤ 0.1 μg/L VT-1) or reduced (0.5 – 5 μg/L VT-1). VT-1 did not cause cellular LDH-release or cell cycle arrest. VT-1 induction of caspase-3 (0.1, 1, and 5 μg/L VT-1), -8, and -9 (1 and 5 μg/L VT-1) activity and DNA fragmentation of T47D cells was blocked by PPMP. Key components of MAP kinase signalling pathways that control mitochondrial function were investigated. VT-1 0

  11. Molecular interactions in binary mixtures of 1-butoxy-2-propanol with alcohols at different temperatures: A thermophysical and spectroscopic approach

    Highlights: • Binary mixtures of 1-butoxy-2-propanol with alcohols have been studied at different temperatures. • Strong H-bonding interactions between the components are confirmed that decreases with increasing chain length of alcohols. • Thermophysical and FT-IR spectroscopic studies strongly corroborate the experimental and computational analysis results. - Abstract: This paper reports densities (ρ) and speeds of sound (u) of 1-butoxy-2-propanol CH3(CH2)3OC3H6OH, 1-propanol CH3(CH2)2OH, 2-propanol (CH3)2CHOH, 1-butanol CH3(CH2)3OH and 2-butanol CH3CH2CH(OH)CH3 and their binary mixtures with 1-butoxy-2-propanol as a common component, measured at T = (293.15, 298.15, 303.15, 308.15 and 313.15) K over the entire composition range. These experimental values of density and speed of sound were used to calculate the values of excess molar volumes, VmE, deviations in molar isentropic compressibility Δκs and deviations in speed of sound uD. Further, experimental densities were used to estimate apparent molar volumes Vϕ,i, partial molar volumes V‾m,1, excess partial molar volumes V‾m,1E and their limiting values at infinite dilution Vϕ,i∞, V‾m,i∞ and V‾m,iE,∞ respectively. The variations observed in these properties, with composition and temperature, are discussed in terms of molecular interactions due to physical and chemical effects between the unlike molecules of the binary mixtures. These properties, especially excess functions, are found to be quite sensitive towards the intermolecular interactions in liquid mixtures. These excess functions and deviations have also been correlated using Redlich–Kister type polynomial equation by the method of least-squares for the estimation of the binary coefficients and the standard errors. FT-IR studies of these mixtures are also reported

  12. Volumetric Properties of Dilute Aqueous Solutions of 1- and 2-propanol to 50 MPa and 373.15 K

    Seitz, J.; Bahramian, J.; Blackwell, R.; Inaki, T.; York, D.; Schulte, M. D.

    2014-12-01

    The need to accurately model and understand reactions among organic compounds and biomolecules in solution is necessary to develop realistic chemical models for the reactions leading to the emergence of life and metabolic processes of extremophiles under elevated temperature and pressure conditions. Unfortunately, the scarcity of experimentally determined volumetric (and other) properties for important compounds at high temperatures and pressures leads to uncertainty in the calculation of reaction properties. Experimentally determined volumetric properties of aqueous solutions at non-standard conditions provide direct tests of current estimation methods and aid in the refinement of these methods. The goal of our research is to provide a database of experimentally determined volumetric properties. In previous studies, we have examined important organic molecules and biomolecules such as adenosine, coenzyme M and D-ribose. In this study, we investigate the volumetric properties of the structural isomers 1- and 2-propanol. 1-propanol (n-propanol) is a primary alcohol (CH3CH2CH2OH) and 2-propanol (isopropanol) is the simplest example of a secondary alcohol (CH3CHOHCH3). These compounds differ slightly in structure depending on to which carbon atom the hydroxyl group is bonded and will provide a sensitive test of current estimation methods and lead to more accurate predictions of the properties of complex aqueous systems at elevated temperatures and pressures. We obtained the densities of aqueous solutions of the alchohols using an Anton Paar DMA HP vibrating tube densimeter. Pressure was measured (pressure transducer) to an accuracy of ±0.01% and temperature was measured (integrated platinum thermometer) with an accuracy of ±0.05 K. Experimental uncertainty of density measurements is less than ±0.0001 g·cm-3. The partial molar volumes at infinite dilution (V∞) for 1- and 2-propanol were calculated from the measured densities and are shown in the figure at 0

  13. Lactivibrio alcoholicus gen. nov., sp. nov., an anaerobic, mesophilic, lactate-, alcohol-, carbohydrate- and amino-acid-degrading bacterium in the phylum Synergistetes.

    Qiu, Yan-Ling; Hanada, Satoshi; Kamagata, Yoichi; Guo, Rong-Bo; Sekiguchi, Yuji

    2014-06-01

    A mesophilic, obligately anaerobic, lactate-, alcohol-, carbohydrate- and amino-acid- degrading bacterium, designated strain 7WAY-8-7(T), was isolated from an upflow anaerobic sludge blanket reactor treating high-strength organic wastewater from isomerized sugar production processes. Cells of strain 7WAY-8-7(T) were motile, curved rods (0.7-1.0×5.0-8.0 µm). Spore formation was not observed. The strain grew optimally at 37 °C (range for growth was 25-40 °C) and pH 7.0 (pH 6.0-7.5), and could grow fermentatively on yeast extract, glucose, ribose, xylose, malate, tryptone, pyruvate, fumarate, Casamino acids, serine and cysteine. The main end-products of glucose fermentation were acetate and hydrogen. In co-culture with the hydrogenotrophic methanogen Methanospirillum hungatei DSM 864(T), strain 7WAY-8-7(T) could utilize lactate, glycerol, ethanol, 1-propanol, 1-butanol, L-glutamate, alanine, leucine, isoleucine, valine, histidine, asparagine, glutamine, arginine, lysine, threonine, 2-oxoglutarate, aspartate and methionine. A Stickland reaction was not observed with some pairs of amino acids. Yeast extract was required for growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite and Fe (III) were not used as terminal electron acceptors. The G+C content of the genomic DNA was 61.4 mol%. 16S rRNA gene sequence analysis revealed that the isolate belongs to the uncultured environmental clone clade (called 'PD-UASB-13' in the Greengenes database) in the bacterial phylum Synergistetes, showing less than 90% sequence similarity with closely related described species such as Aminivibrio pyruvatiphilus and Aminobacterium colombiense (89.7% and 88.7%, respectively). The major cellular fatty acids were iso-C(13 : 0), iso-C(15 : 0), anteiso-C(15 : 0), C(18 : 1), C(19 : 1), C(20 : 1) and C(21 : 1). A novel genus and species, Lactivibrio alcoholicus gen. nov., sp. nov. is proposed to accommodate strain 7WAY-8-7(T) ( = JCM 17151(T

  14. 苯酚-间甲酚-糠醛基炭气凝胶的制备及微结构控制%Preparation and microstructure control of carbon aerogels produced using m-cresol mediated sol-gel polymerization of phenol and furfural

    龙东辉; 张洁; 杨俊和; 胡子君; 李同起; 成果; 张睿; 凌立成

    2008-01-01

    以苯酚、间甲酚和糠醛为原料,在正丙醇溶剂中以盐酸为催化剂经溶胶-凝胶过程合成了醇凝胶,直接超临界正丙醇干燥得到有机气凝胶,在氮气保护下裂解制备出富含中孔的炭气凝胶.用IR、N2吸附、SEM、TEM等表征气凝胶的结构特征,考察了问甲酚苯酚摩尔比对凝胶结构的影响.结果发现:提高间甲酚的含量能够增强聚合物的交联密度,减小聚合物与溶剂的相溶性,缩短相分离时间,有利于得到较小的纳米颗粒和孔径的炭气凝胶.所制得的炭气凝胶平均中孔孔径随间甲酚含量的增加从47 nm逐渐减小至13 nm,BET比表面积和中孔孔容在m-C/P=0.33时达到最大值.%Carbon aerogels rich in mesopores were prepared by the sol-gel polycondensation of phenol, m-cresol, and furfural by an acid catalyst in a 1-propanol solution, followed by supercritical l-propanol drying and pyrolysis. The effect of the ratios of m-cresol to phenol (m-C/P) on the properties of aerogels was investigated. The aerogels were characte- rized by infrared spectroscopy, N2 adsorption, scanning and transmission electron microscopy. It was found that the microstructure of carbon aerogels could be adjusted by the m-C/P ratio. The average mesopore size of carbon aerogels decreased from 47 to 13 nm with increasing m-C/P ratio. The surface area calculated using the Brunauer-Emmett-Teller method, external surface area, and mesopore volume of carbon aerogels, all exhibited maxima at the m-C/P ratio of 0.33.

  15. A calorimetric and equilibrium investigation of the reaction {methyl ferulate(aq) + H2O(l) = methanol(aq) + ferulic acid(aq)}

    Microcalorimetry and high-performance liquid chromatography (HPLC) have been used to conduct a thermodynamic investigation of the reaction: {methyl ferulate(aq) + H2O(l) = methanol(aq) + ferulic acid(aq)}, as catalyzed by feruloyl esterase. Values of the apparent equilibrium constant K' = (29.6 ± 0.7) (T = 298.15 K, citrate buffer at pH 4.98, ionic strength I = 0.39 mol · kg-1) and of the calorimetrically determined enthalpy of reaction ΔrH(cal) = (4.0 ± 0.9) kJ · mol-1 (T = 298.15 K and citrate buffer at pH 4.81, I = 0.36 mol · kg-1) were measured. A chemical equilibrium model, together with pKs and standard enthalpies of reaction ΔrH0 for the H+(aq) binding reactions of the reactants and products, was then used to calculate the values K = (1.89 ± 0.06) . 10-4, ΔrHo = (7.3 ± 1.7) kJ · mol-1, ΔrGo = (21.25 ± 0.07) kJ · mol-1, and ΔrSo = - (46.8 ± 5.7) J · K-1 · mol-1 for the chemical reference reaction {methyl ferulate(aq) + H2O(l) = methanol(aq) + ferulic acid-(aq) + H+(aq)}. These values of K and ΔrHo are similar in magnitude to the corresponding values reported for the reaction {propyl gallate(aq) + H2O(l) = 3,4,5-trihydroxybenzoic acid-(aq) + 1-propanol(aq) + H+(aq)}. The results obtained in this study can be used in a chemical equilibrium model to calculate how K' and other standard transformed properties such as the standard transformed enthalpy ΔrH'o, standard transformed Gibbs free energy ΔrG'o, and the change in binding of H+(aq), ΔrN(H+), vary with the independent variables T, pH, and I.

  16. 溴化1-癸基-3-甲基咪唑离子液体+脂肪醇二元溶剂体系的物理化学性质%Physicochemical properties of binary mixtures {[C10 mim]Br + alcohol}

    张云霞; 李淑妮; 翟全国; 蒋育澄; 胡满成

    2015-01-01

    The density(ρ),refractive index(nD ),and dynamic viscosity(η),for the three binary solutions containing 1-decyl-3-methylimidazolium bromide([C10 mim]Br)and fatty alcohol{ethyl-ene glycol (EG),1,2-propanediol (PG),and 1-propanol (NPA)}were investigated,respectively at temperatures of 288.15~308.15 K and under ambient pressure.Additionally,the excess molar volume(V Em ),and deviation of the refractive index(ΔnD),were calculated and correlated using the Redlich-Kister polynomial equation.The variation of density,refractive index and viscosity with the composition was described by the polynomial equations.The influence of carbon-chain length and the hydroxyl number of the fatty alcohol,and the influence of the temperature on the physi-cochemical properties of the binary systems can be explained by the comparison of the experimen-tal results.%在大气压力0.1 MPa 及288.15~308.15 K 温度下测定了溴化1-癸基-3-甲基咪唑离子液体([C10 mim]Br)+脂肪醇{乙二醇(EG)/1,2-丙二醇(PG)/正丙醇(NPA)}三个二元体系的密度(ρ)、折光率(nD )和黏度(η)。计算获得了过量摩尔体积(V Em )和折光率偏差(Δn D ),并用 Redlich-Kister 方程对衍生性质数据进行拟合。密度、折光率和黏度值随组成的变化用多项式方程进行了拟合。通过对实验数据的比较,总结出脂肪醇的碳链长度和羟基个数以及温度等对物化性质的影响。

  17. Insights on Alterations to the Rumen Ecosystem by Nitrate and Nitrocompounds

    Latham, Elizabeth A.; Anderson, Robin C.; Pinchak, William E.; Nisbet, David J.

    2016-01-01

    Nitrate and certain short chain nitrocompounds and nitro-oxy compounds are being investigated as dietary supplements to reduce economic and environmental costs associated with ruminal methane emissions. Thermodynamically, nitrate is a preferred electron acceptor in the rumen that consumes electrons at the expense of methanogenesis during dissimilatory reduction to an intermediate, nitrite, which is primarily reduced to ammonia although small quantities of nitrous oxide may also be produced. Short chain nitrocompounds act as direct inhibitors of methanogenic bacteria although certain of these compounds may also consume electrons at the expense of methanogenesis and are effective inhibitors of important foodborne pathogens. Microbial and nutritional consequences of incorporating nitrate into ruminant diets typically results in increased acetate production. Unlike most other methane-inhibiting supplements, nitrate decreases or has no effect on propionate production. The type of nitrate salt added influences rates of nitrate reduction, rates of nitrite accumulation and efficacy of methane reduction, with sodium and potassium salts being more potent than calcium nitrate salts. Digestive consequences of adding nitrocompounds to ruminant diets are more variable and may in some cases increase propionate production. Concerns about the toxicity of nitrate's intermediate product, nitrite, to ruminants necessitate management, as animal poisoning may occur via methemoglobinemia. Certain of the naturally occurring nitrocompounds, such as 3-nitro-1-propionate or 3-nitro-1-propanol also cause poisoning but via inhibition of succinate dehydrogenase. Typical risk management procedures to avoid nitrite toxicity involve gradually adapting the animals to higher concentrations of nitrate and nitrite, which could possibly be used with the nitrocompounds as well. A number of organisms responsible for nitrate metabolism in the rumen have been characterized. To date a single rumen bacterium

  18. The promotional effects of cesium promoter on higher alcohol synthesis from syngas over cesium-promoted Cu/ZnO/Al2O3 catalysts

    Sun, Jie; Cai, Qiuxia; Wan, Yan; Wan, Shaolong; Wang, Li; Lin, Jingdong; Mei, Donghai; Wang, Yong

    2016-09-02

    In this study, the promotional effects of cesium promoter on higher alcohol (C2+OH) synthesis from syngas over Cs-Cu/ZnO/Al2O3 catalysts were investigated using a combined experimental and theoretical density functional theory (DFT) calculation method. In the presence of cesium, the C2+OH productivity increases from 77.1 g•kgcat-1•h-1 to 157.3 g•kgcat-1•h-1 at 583 K due to the enhancement of the initial C–C bond formation. Detailed analysis of chain growth probabilities (CGPs) confirms that initial C–C bond formation is the rate-determining step in the temperature range of 543-583 K. Addition of cesium promoter significantly increases the productivities of 2-methyl-1-propanol, while the CGPs values (C3* to 2-methyl-C3*) is almost unaffected. With the assistance of cesium promoter, the CGPs of the initial C–C bond formation step (C1* to C2*) could be increased from 0.13 to 0.25 at 583 K. DFT calculations indicate that the initial C–C bond formation is mainly contributed by the HCO+HCO coupling reaction over the ZnCu(211) model surface. In the presence of the Cs2O, the stabilities of key reaction intermediates such as HCO and H2CO are enhanced which facilitates both HCO+HCO and HCO+H2CO coupling reaction steps with lower activation barriers over the Cs2O-ZnCu(211) surface. The promotional effects of cesium on the C2+OH productivity are also benefited from the competitive CH+HCO coupling reaction over CH hydrogenation that leads to lower alkane formation. In addition, Bader charge analysis suggests that the presence of cesium ions would facilitate the nucleophilic reaction between HCO and H2CO for initial C–C bond formation. This work was supported by the National Natural Science Foundation of China (No. 91545114 and No. 91545203). We appreciate the joint PhD scholarship support from the China Scholarship Council. The authors would also like to thank the support from Collaborative Innovation Center of Chemistry for Energy Materials (2011-iChEM). DM

  19. Green LPG

    Hulteberg, Christian; Brandin, Jan; Leveau, Andreas (Biofuel-Solution AB, Limhamn (Sweden))

    2010-12-15

    readily available as the production of biofuels (from which glycerine is a side product) in the world has increased markedly over the last 10 year period. This glut in the glycerol production has also lowered worldwide prices of glycerine. Since the key step in producing energy gases from glycerol is the dehydration of glycerol to acrolein, this step has attracted much attention during the development work. The step has been improved during the performed work and the need for any regeneration of the catalyst has been significantly reduced, if not omitted completely. This improvement allows for a simple fixed bed reactor design and will save cost in reactor construction as well as in operating costs of the plant. The same conclusion can be drawn from the combination of the two functionalities (dehydration and hydrogenation) in designing a catalyst that promote the direct reaction of 1-propanol to propane in one step instead of two. The experiments with the decarbonylation of acrolein to form ethane show that the catalyst deactivation rates are quite rapid. The addition of noble metal to the catalyst seems to improve the longevity of the catalyst, but the coking is still too severe to provide for a commercially viable process. It is believed that there is a possible way forward for the decarbonylation of acrolein to ethane; it will however require additional time and resources spent in this area. In this work it has been shown that all of the catalytic steps involved in the production of propane from glycerol have sufficient longterm stability and endurance and it is motivated to recommend that the project continues to pilot plant testing stage

  20. A calorimetric and equilibrium investigation of the reaction {l_brace}methyl ferulate(aq) + H{sub 2}O(l) = methanol(aq) + ferulic acid(aq){r_brace}

    Goldberg, Robert N., E-mail: robert.goldberg@nist.go [Biochemical Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20876 (United States); Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Lang, Brian E., E-mail: brian.lang@nist.go [Biochemical Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20876 (United States); Selig, Michael J., E-mail: michael.selig@nrel.go [National Renewable Energy Laboratory, Biosciences Center, 1617 Cole Boulevard, Golden, CO 80401 (United States); Decker, Stephen R., E-mail: steve.decker@nrel.go [National Renewable Energy Laboratory, Biosciences Center, 1617 Cole Boulevard, Golden, CO 80401 (United States)

    2011-03-15

    Microcalorimetry and high-performance liquid chromatography (HPLC) have been used to conduct a thermodynamic investigation of the reaction: {l_brace}methyl ferulate(aq) + H{sub 2}O(l) = methanol(aq) + ferulic acid(aq){r_brace}, as catalyzed by feruloyl esterase. Values of the apparent equilibrium constant K' = (29.6 {+-} 0.7) (T = 298.15 K, citrate buffer at pH 4.98, ionic strength I = 0.39 mol {center_dot} kg{sup -1}) and of the calorimetrically determined enthalpy of reaction {Delta}{sub r}H(cal) = (4.0 {+-} 0.9) kJ {center_dot} mol{sup -1} (T = 298.15 K and citrate buffer at pH 4.81, I = 0.36 mol {center_dot} kg{sup -1}) were measured. A chemical equilibrium model, together with pKs and standard enthalpies of reaction {Delta}{sub r}H{sup 0} for the H{sup +}(aq) binding reactions of the reactants and products, was then used to calculate the values K = (1.89 {+-} 0.06) . 10{sup -4}, {Delta}{sub r}H{sup o} = (7.3 {+-} 1.7) kJ {center_dot} mol{sup -1}, {Delta}{sub r}G{sup o} = (21.25 {+-} 0.07) kJ {center_dot} mol{sup -1}, and {Delta}{sub r}S{sup o} = - (46.8 {+-} 5.7) J {center_dot} K{sup -1} {center_dot} mol{sup -1} for the chemical reference reaction {l_brace}methyl ferulate(aq) + H{sub 2}O(l) = methanol(aq) + ferulic acid{sup -}(aq) + H{sup +}(aq){r_brace}. These values of K and {Delta}{sub r}H{sup o} are similar in magnitude to the corresponding values reported for the reaction {l_brace}propyl gallate(aq) + H{sub 2}O(l) = 3,4,5-trihydroxybenzoic acid{sup -}(aq) + 1-propanol(aq) + H{sup +}(aq){r_brace}. The results obtained in this study can be used in a chemical equilibrium model to calculate how K' and other standard transformed properties such as the standard transformed enthalpy {Delta}{sub r}H'{sup o}, standard transformed Gibbs free energy {Delta}{sub r}G'{sup o}, and the change in binding of H{sup +}(aq), {Delta}{sub r}N(H{sup +}), vary with the independent variables T, pH, and I.

  1. Liquid biofuel production from volatile fatty acids

    Steinbusch, K.J.J.

    2010-03-19

    dominated by relatives of Clostridium kluyveri. VFA could also be reduced to alcohols. Acetic, propionic and butyric acids were biohydrogenated with hydrogen and acetic acid also with an electrode. Observed alcohol concentrations were 0.62 g L{sup -1} ethanol, 0.49 g L{sup -1} propanol and 0.27 g L{sup -1} n-butanol. Methanogenesis was successfully inhibited after thermal pre-treatment incubated at pH 6, while acetate reduction was enhanced. In the second study, ethanol (0.084 g L{sup -1}) was produced at the cathodic compartment of a bioelectrochemical system, in which the electron transport was mediated by methyl viologen. The ethanol production activity at the cathode was only of very short term, since the mediator irreversibly reacted at the surface of the cathode. Of the two VFA conversion processes, biohydrogenation and chain elongation, the latter was a more dominant process that consumes ethanol with acetate to medium chain fatty acids. With this technology, wet organic waste can be converted to biofuels carbon and energy efficient. The technology is promising due to the good fuel and separation properties of medium chain fatty acids, and the possibility to produce them at high concentrations and specific production rates comparable to other anaerobic conversions.

  2. Oxy-combustion of high water content fuels

    Yi, Fei

    As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low speed diesel-type engine. The proposed processes could provide alternative approaches to directly utilize fuels which intrinsically have high water content. A large amount of energy to remove the water, when the fuels are utilized in a conventional approach, is saved. The properties and difficulty in dewatering high water content fuels (e.g. bioethanol, microalgae and fine coal) are summarized. These fuels include both renewable and fossil fuels. In addition, the technique can also allow for low-cost carbon capture due to oxy-combustion. When renewable fuel is utilized, the whole process can be carbon negative. To validate and evaluate this concept, the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the fuels and the flame stability maps were obtained. Flame stability, as characterized by the blow-off limit -- the lowest O2 concentration when a flame could exist under a given oxidizer flow rate, was determined as a function of total oxidizer flow rate, fuel concentration and nozzle type. Furthermore, both the gas temperature contour and the overall ethanol concentration in the droplets along the

  3. The Production of Biodiesel from Cottonseed Oil Using Rhizopus oryzae Whole Cell Biocatalysts

    Athalye, Sneha Kishor

    accumulation of 15.6 g (dry cell wt)/L. A reduction in dynamic viscosity of the reaction mixture from 47.3 centipoise to 30.6 centipoise was observed. The impact of moisture addition to the reaction mixture and use of ethanol as acylating agent on R.oryzae BSP fatty acid alkyl ester production was also tested. The presence of 10 wt % moisture in the reaction system had a significant effect (p ≤ 0.05) on the transesterification reaction with ethanol unlike methanol. Fatty acid ethyl ester concentration tripled from 39.3 to 129.1 g/L when moisture was added during transesterification .When oil to acyl acceptor ratio was increased from 1:3 and 1:6 to determine effect of excess alcohol on conversion, an ester conversion of 128.1 g/L for methanol and 129.1 g/L for ethanol were observed. Use of excess amount of acylating agent had a significant adverse effect (p ≤ 0.05) on the overall FAAE production due to deactivation of lipases on contact with large amounts of insoluble alcohol in the oil phase of the reaction. The effect of short chain alcohols on the enzymatic transesterification of cottonseed oil using freeze dried Rhizopus oryzae biomass was examined with and without water addition using methanol, ethanol, 1-Propanol and 1-Butanol at various molar ratios. 1- Butanol in the absence of water resulted in a significantly higher (p . 0.1) conversion of cottonseed oil to 12.5 % fatty acid butyl esters (FABEs). Addition of 10 % water to the reaction mixture significantly reduced (p ≤ 0.1) conversion. No significant difference (p > 0.1) between the conversions was observed for time points after 24 h for a 72 h reaction. 1- Butanol in ratios higher than 3:1 to cottonseed oil had a significant impact (p ≤ 0.1) on conversion. Increasing the amount of biomass used during the reaction lead to significantly higher conversion (p ≤ 0.1). The highest conversion of 27.9 % was observed for the transesterification reaction between cottonseed oil and 1-Butanol, in a 1:6 molar ratio, in

  4. Oxygenates vs. synthesis gas

    Kamil Klier; Richard G. Herman; Alessandra Beretta; Maria A. Burcham; Qun Sun; Yeping Cai; Biswanath Roy

    1999-04-01

    Methanol synthesis from H{sub 2}/CO has been carried out at 7.6 MPa over zirconia-supported copper catalysts. Catalysts with nominal compositions of 10/90 mol% and 30/70 mol% Cu/ZrO{sub 2} were used in this study. Additionally, a 3 mol% cesium-doped 10/90 catalyst was prepared to study the effect of doping with heavy alkali, and this promoter greatly increased the methanol productivity. The effects of CO{sub 2} addition, water injection, reaction temperature, and H{sub 2}/C0 ratio have been investigated. Both CO{sub 2} addition to the synthesis gas and cesium doping of the catalyst promoted methanol synthesis, while inhibiting the synthesis of dimethyl ether. Injection of water, however, was found to slightly suppress methanol and dimethyl ether formation while being converted to CO{sub 2} via the water gas shift reaction over these catalysts. There was no clear correlation between copper surface area and catalyst activity. Surface analysis of the tested samples revealed that copper tended to migrate and enrich the catalyst surface. The concept of employing a double-bed reactor with a pronounced temperature gradient to enhance higher alcohol synthesis was explored, and it was found that utilization of a Cs-promoted Cu/ZnO/Cr{sub 2}O{sub 3} catalyst as a first lower temperature bed and a Cs-promoted ZnO/Cr{sub 2}O{sub 3} catalyst as a second high-temperature bed significantly promoted the productivity of 2-methyl-1-propanol (isobutanol) from H{sub 2}/CO synthesis gas mixtures. While the conversion of CO to C{sub 2+} oxygenates over the double-bed configuration was comparable to that observed over the single Cu-based catalyst, major changes in the product distribution occurred by the coupling to the zinc chromite catalyst; that is, the productivity of the C{sub 1}-C{sub 3} alcohols decreased dramatically, and 2-methyl branched alcohols were selectively formed. The desirable methanol/2-methyl oxygenate molar ratios close to 1 were obtained in the present double

  5. Rapid fabrication of aluminum nitride with high thermal conductivity by millimeter-wave heating method

    Full text: Aluminum nitride has been interested for the usage of heat-sink substrate in the semiconductor device on account of its high thermal conductivity. But aluminum nitride is not so easily sintered similarly as other nitrides. Polycrystalline bulk aluminum nitride is generally sintered by adding some sintering aids. However, high sintering temperature around 2000 deg C is still required for attaining full densification with the conventional sintering method. In the present study, we show millimeter-wave heating method is the rapid and low temperature process for producing aluminum nitride with high thermal conductivity. Importance in the selection of sintering aid is indicated in the millimeter-wave sintering of aluminum nitride. The relation between thermal conductivity and microstructure is also discussed. AlN powder with the average size of 1μm (Mitsui Kagaku, MAN-2) was used as the starting raw material and Y2O3 or Yb2O3 (Shin-etsu Kagaku, average size; 0.25μm and 1.2μm, UU- and RU-grades, respectively) were used as sintering aids, respectively. After mixing AlN powder and sintering aid at a desired content, the mixed powder with 1-propanol and dispersant was milled for 20 hr with alumina balls in an alumina pot. The milled powder was shaped to the circular disk with 40 mm in diameter and 4-5 mm in thickness by slip-casting method. After drying enough, the slip-casted body was calcined at 600 deg C for 1 h in nitrogen atmosphere. The calcined body was sintered in nitrogen without hydrogen or with several % hydrogen by using millimeter-wave heating method. Millimeter-wave heating was performed in a multi-mode applicator (Fuji Denpa Kogyo, FGS-10-28) combined with a high power 28 GHz gyrotron generator. Density of sintered body was calculated from measured size and weight, and when the relative density was over 90%, the precise density was measured by Archimedean method using oleic acid as immersion liquid. Thermal conductivity of sintered body was