Search

A handheld refractometer (HHR) is a versatile instrument in the chemistry lab or in the workplace. It is also inexpensive enough (

The separation of a ternary mixture containing methyl methacrylate (MMA)-methanol-water is challenging owing to MMA forming a ternary azeotrope with methanol and water. Herein, water was employed a...

The solubilities of fluoxetine hydrochloride (FH) in pure solvents including methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, s-butanol, n-pentanol, i-pentanol, acetone, 2-butanone,...

A copper-catalyzed one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-ones with diboronic acid as a reductant in an aqueous medium is described. Various 2,3-dihydroquinazolin-4(1H)-ones were prepared with good functional-group tolerance in good yields under mild conditions from readily available 2-nitrobenzonitriles and various carbonyl compounds.

The aqueous phase hydrogenation of furfural to cyclopentanone over a NiFe bimetallic catalyst was investigated for the efficient utilization of biomass-derived compounds. Catalyst characterization ...

High-performance separation and purification present essential obstacles for the application of biosurfactant mannosylerythritol lipids (MEL) in many fields. In this study, we developed an extraction process, which efficiently isolates MEL from fermentation broth with the solvent system methanol/water/n-hexane. At pH 2, extraction with methanol/water/n-hexane at a ratio of 2:1:1 recovers about 80% MEL, and the following extraction with methanol/water/n-hexane at ratio of 3:1:1 can further recover about 14% MEL. After that, MEL were purified using a methanol/n-hexane mixture with a ratio of 1:1. The whole presented extraction process recovers over 90% MEL with high purity, excellent surface activities, excellent surface activity (reduce the surface tension of water to below 28 mN/m at a concentration of 15 mg/L), and high emulsification activity (E24 of 85–96%). This efficient and easy-to-operate separation process has the potential to contribute to industrial applications of MEL in many fields requiring high purity.

The present study considers a tubular reformer packed with CuO/ZnO/Al2O3 catalyst and heater tubes. Five different fuels are considered, namely four methanol-water fuels with molar ratios of 40%:60...

The use of methanol–water mixtures as solvents for sample preparations is common in many instrumental analytical procedures for compound quantification at trace concentration levels. The reliability of the analytical method depends upon several factors including consistency of instrumental setup and calibration, quality of standards used and operator’s lab actions, among others. This proposal describes a student-centered project that relates the concept of molar partial volume and transfer it to an actual and relevant lab situation which aims at promoting critical thinking in undergraduate chemistry students. Through its implementation, students are asked to reflect on the impact that a simple laboratory operation (such as the way of preparing a hydroalcoholic mixture) may have on the accuracy of a pesticide quantification, namely, thiabendazole, using native molecular fluorescence determination.

The first dissociation constant of piperazinium ion has been determined by the emf method in five methanol-water solvents (10 to 70 wt % MeOH) at 25 °C and in three solvents (10, 20, and 50 wt % MeOH) from 10 to 40 °C. From the variation of the dissociation constant with temperature, the changes of enthalpy, entropy, and heat capacity were derived and compared with similar data for piperazinium ion in water. The variation of pK, ΔS°, and [Formula: see text] have been used to interpret the effect of the double positive charge on the solute-solvent interactions as compared to the effect exhibited by a single positive or a negative charge.

The interaction of Methylene blue with Cetylpyridinium chloride (CPC) in a series of solvents containing 0.1, 0.2 and 0.3 volume fractions of methanol in water were studied at room temp (300±2 K) by UV-Vis spectrophotometer. The CPC concentrations were varied from 0.2 x 10-3 to 2 x 10-3 mol dm-3. A fixed dye concentration of 2.5 x 10-5 mol dm-3 was used for this purpose. The spectrum analysis was performed for both the dye solution and mixtures containing dye and surfactant of different concentrations. The dye solution showed the absorbance maximum at 664 nm and a shoulder at 610 nm. In 0.3 volume fraction of methanol as solvent, the dye and surfactant mixed solution showed a shift in peak values towards shorter wavelength (blue shift) from peak of the dye solution. The shift in peak increased with increase in surfactant concentration up to 0.6 x10-3 mol dm-3, beyond which no further shift increment occurred. In the case of 0.1 and 0.2 volume fractions of methanol in water, no shift in peak was found at all concentrations of dye and surfactant. The absorbance of dye and surfactant mixed solution decreased gradually in 0.2 volume fraction of methanol with increase in surfactant concentration, whereas no significant change in absorbance was seen in 0.1 volume fraction of methanol. The shift decreased gradually with decrease in methanol concentration in the solvent.

The trained version of modified Wilson model is proposed employing solubility data of 41 drugs and/or drug-like compounds in methanol + water mixtures at various temperatures. For covering the physicochemical properties of the solute to provide a QSPR model, the Abraham solvation parameters of solutes are combined with the modified Wilson model. The mean relative deviations for the correlated data are 32.5% and 27.1%, respectively for the modified Wilson model and its combined version with Abraham solvation parameters. Furthermore, an attempt is also made to correlate the solubility data with the modified Wilson model combined with van't Hoff equation and the Abraham general solvation parameters to provide a full predictive model for drug solubility prediction in methanol + water mixtures at various temperatures.

The aim of this study is to develop the trained versions of Yalkowsky and Jouyban-Acree models for the prediction of drug solubility in the binary aqueous mixtures of methanol (MeOH) at various temperatures. To provide a full predictive model, the Abraham solvation parameters of solutes are combined with the proposed models. The solubility data of 41 drug and/or drug-like compounds with different polarities and structural features covering the total drug-like space are fitted by these models. The generally trained models provide reasonable estimation of the solubility behavior of drugs and can be helpful in the pharmaceutical industry.

H 2 evolution from photocatalytic decomposition by liquid phase plasma was examined over Ag-loaded photocatalysts. The effect of methanol addition into water was estimated in the photocatalytic water splitting. Photocatalytic activity of perovskite was also assessed in the photocatalytic water splitting. H 2 was evolved in the photocatalytic splitting of water by reacting of active species. The photocatalytic activity for H 2 generation of TiO 2 prepared by sol-gel method was higher than that of commercial TiO 2 photocatalyst. The rate of H 2 evolution was progressed with Ag loading on TiO 2 photocatalysts. The addition of methanol into water brought to a significant enhancement of H 2 evolution. The methanol acted as an electron donor to increase the amount of H 2 production.

The oscillatory circulation inside an evaporating methanol – water mixture drop at various surrounding temperatures, is reported. The cyclic acceleration and deceleration of the flow inside and around the center of the drop, is termed oscillatory circulation. The volume fraction of methanol in the mixture was varied and the evaporation was recorded at various surrounding temperatures. The study finds that the oscillation diminishes as the temperature of the surrounding increases. The peak (i.e., maxima) frequency of the oscillation among all the volume fraction tested, is observed to be a strong function of the surrounding temperature. The variation of frequency with volume fraction shows that the peak shifts to the higher side of the volume fraction as the temperature is increased. The combined effect of the thermal Marangoni, solutal Marangoni, and solutal Rayleigh convection, was found to control the oscillatory circulation process.

The circulation inside various evaporating methanol – water drops in an inert and quiescent environment, is studied. The circulation is visualized using laser. An oscillatory internal circulation resulting from the opposing effects of thermal and solutal Marangoni convection is observed. The speeding up and slowing down of the convection roll (as visualized from the path-lines of the seeding particles) in the drop interior and around the centre, is termed oscillation. The circulation demonstrates novel feature for various methanol – water drops. The frequency of oscillation increases up to a volume fraction of 0.5 of methanol, and reduces afterwards. From the variation of Marangoni and Rayleigh numbers with volume fraction, it is demonstrated that the variation in frequency results from the complex interaction between the thermal Marangoni, solutal Marangoni, and solutal Rayleigh convection. The opposing effect of the thermal Marangoni and solutal Marangoni convection tries to enhance the oscillatory internal circulation, whereas, the solutal Rayleigh convection makes the circulation steadier. Hence, the frequency increases with the volume fraction initially (up to 0.5), but reduces afterwards. The characteristics of the circulation predominantly depend on the solutal Marangoni convection.

A technological scheme for drying binary solutions, which allows separating two-component solutions and complex systems using molecular size difference (molecular sieves), has been designed. Analysis of modern adsorbents produced by the domestic chemical industry was carried out, and the optimal parameters of the investigated zeolite adsorbents were determined for the regeneration and cooling processes that accompany the restoration of the adsorption properties of the adsorbents used. A mathematical model for calculating the adsorption of a water-methanol mixture on solid adsorbents has been developed and can be used for other processes, for example, for the drying of alcoholic solutions with components of polyhydric alcohols and water. A technique for calculating the separation units for binary systems is proposed.

available on the full text PDF.

Random copolymer gels of N -isopropylacrylamide (NIPAM) and N -ethylacrylamide (NEAM) were synthesized in using different monomer compositions in 1:1 methanol-water mixtures and in pure water. The samples were characterized by cononsolvency study in methanol-water mixtures at various temperatures by swelling ratio measurements. It is observed that with the variation of the temperature and monomer compositions in the synthesis reaction mixture, the cononsolvency properties varied significantly. But the variation in the solvents compositions by keeping monomer compositions fixed does not affect the cononsolvency much. All results can be explained on the basis of the differences in thermoresponsive character or difference in the hydrophilicity of PNIPAM and PNEAM in water, preferential adsorption of the solvents by polymer networks, solvent-solvent interactions, heterogeneity of the polymer networks synthesized at different solvent compositions and at different temperatures, difference in their morphological properties, etc.

A combination of temperature-dependent Raman spectroscopy and quantum chemistry calculation was employed to investigate the blue shift of CH3 stretching vibration in methanol–water mixtures. It shows that the conventional O–H···O hydrogen bonds do not fully dominate the origin of the C–H blue shift and the weak C–H···O interactions also contribute to it. This is consistent with the temperature-dependent results, which reveal that the C–H···O interaction is enhanced upon increasing the temperature, leading to further C–H blue shift in observed spectra at high temperature. This behavior is in contrast with the general trend that the conventional O–H···O hydrogen bond is destroyed by the temperature. The results will shed new light onto the nature of the C–H···O interaction and be helpful to understand hydrophilic and hydrophobic interactions of amphiphilic molecules in different environments.

Mathematical representations reported by Li et al. for a number of cosolvency models are carefully examined concerning the models’ abilities to predict the solubility of maltitol in binary aqueous mixtures of methanol and ethanol at various temperatures. Some further recommendations on computational methods are also provided to be employed in the future research works. Preferential solvation of the solution was also investigated to provide better understanding of the dissolution process.

Methyl, ethyl and propyl parabens equilibrium solubility was determined in (methanol + water) binary mixtures at 298.15 K. The mole fraction solubility of these compounds increased in 503 (from 2.40 × 10−4 to 0.121), 1377 (from 9.86 × 10−5 to 0.136) and 4597 (from 3.73 × 10−5 to 0.171) times when passing from neat water to neat methanol, for methyl, ethyl and propyl parabens, respectively. All these solubility values were correlated with the Jouyban-Acree model. Preferential solvation parameters by methanol (δx1,3) of these parabens were derived from their thermodynamic solution properties using the inverse Kirkwood-Buff integrals (IKBI) method. For all compounds δx1,3 values are negative in water-rich mixtures but positive in mixtures with methanol mole fraction greater than 0.32. It is conjecturable that in the former case the hydrophobic hydration around non-polar groups of parabens plays a relevant role in the solvation. Besides, the preferential solvation of these solutes by methanol in mixtures of similar co-solvent compositions and in methanol-rich mixtures could be explained in terms of the higher basic behaviour of methanol.

В докладе представлены результаты моделирования термодинамических свойств бинарного раствора вода-метанол методом Монте-Карло на основе оптимизированных потенциалов межмолекулярного взаимодействия. Полученный массив данных сравнивался с, имеющимся для данной смеси, многоконстантным уравнением состояния. Отклонения данных моделирования от расчетных по уравнению состояния близки к погрешностям экспериментального определения соответствующих свойств. Показано, что предлагаемый подход может быть использован в дальнейшем для моделирования термодинамических свойств перспективных рабочих тел абсорбционных преобразователей теплоты, для которых имеется недостаток экспериментальных данных.

The surface activity and the process of micellization of sodium dodecyl sulfate (SDS) with methylene blue (MB) in a methanol-water mixed solvent system were investigated by tensiometry and conductometry at 298.15 K. The measurements of surface tension and conductivity of SDS-MB complex were carried up to 0.3 volume fractions of methanol because the resulting complex appeared turbid above 0.3 volume fractions of methanol. The critical micelle concentration (CMC) of the SDS was determined from both tensiometry and conductometry. The CMC of SDS increased with the increasing volume fraction of methanol due to the inclusion of methanol in the micelles and decreased in the presence of methylene blue due to the reduction of electrostatic repulsion within the anionic moiety of SDS by the positive charge of the added dye. Different properties like surface excess concentration Γ max , minimum surface area A min , Gibbs free energy of micellization Δ G m o , surface pressure ( π CMC ), efficiency of a surfactant ( p C 20 ), packing parameter P , and standard free energy interfacial adsorption Δ G ads o of SDS in the absence/presence of MB were calculated. On the basis of Δ G m o values, it was noticed that the increasing volume fraction of methanol disfavors the micellization of SDS, while the presence of MB increased the efficiency of SDS making the micellization process more spontaneous.

The micellization behavior of cetyltrimethylammonium bromide (CTAB) in water , 0.1, 0.2, 0.3, and 0.4 volume fractions of methanol at 298.15, 308.15, 318.15, and 323.15 K were investigated by surface tension measurements. The effect of methanol on values of critical micelle concentration (cmc), free energies of micellization ΔGmo, and surface properties viz. maximum surface excess concentration Γmax, area occupied by per surfactant molecule Amin, surface pressure πcmc, solution surface tension γcmc, solvent surface tension (γo), free energies of adsorption ΔGadso, the efficiency of adsorption (pC20), effective Gibbs free energy ΔGeffo, and free energy of surface at equilibrium (Gmin) were investigated using surface tension values. Other parameters such as the packing parameter (P), aggregation number (N), concentration of surfactant in the bulk phase (C20), relation between Amin and πcmc, and correlation of slopes dγ/d log C, γo/γcmc, Γ/Γmax, cmc/C20, ΔGadso/ΔGmo, and cmc/pC20 with the volume fraction of methanol are calculated and discussed in the light of the experiment done.

C25H28N6O7Zn, triclinic, P1̄ (no. 2), a = 7.8073(19) Å, b = 11.350(3) Å, c = 15.515(4) Å, α = 95.006(2)°, β = 101.828(3)°, γ = 102.050(4)°, V = 1303.8(5) Å3, Z = 2, R gt(F) = 0.0429, wR ref(F 2) = 0.1153, T = 153(2) K.

The refractive index of the methanol-water mixture depending on the wavelength at different concentrations was determined by our experimental method using a Michelson interferometer system. A comparative study of Gladstone-Dale, Arago–Biot and Newton relations for predicting the refractive index of a liquid has been carried out to test their validity for the methanol-water mixture with the different concentrations 30%, 40%, 50%, 60%, 80%, and 100%. The comparison shows the good agreement between our experimental results and the results in the expressions studied over the wavelength range approximately from 450 to 850 nm. Full Text: PDF References S. Sharma, P.B. Patel, R.S. Patel, "Density and Comparative Refractive Index Study on Mixing Properties of Binary Liquid Mixtures of Eucalyptol with Hydrocarbons at 303.15, 308.15 and 313.15 K", E-Journal of Chemistry 4(3), 343 (2007). CrossRef A. Gayathri, T. Venugopal, R. Padmanaban, K. Venkatramanan, R. Vijayalakshmi, "A comparative study of experimental and theoretical refractive index of binary liquid mixtures using mathematical methods", IOP Conf. Series: Materials Science and Engineering 390, 012116 (2018). CrossRef A. Jahan, M.A. Alam, M.A.R. Khan, S. Akhtar, "Refractive Indices for the Binary Mixtures of N, N-Dimethylformamide with 2-Butanol and 2-Pentanol at Temperatures 303.15 K, 313.15 K, and 323.15 K", American Journal of Physical Chemistry 7(4), 55 (2018). CrossRef N. An, B. Zhuang, M. Li, Y. Lu, Z. Wang, "Combined Theoretical and Experimental Study of Refractive Indices of Water–Acetonitrile–Salt Systems", J. Phys. Chem. B 119(33), 10701 (2015). CrossRef M. Upadhyay, S.U. Lego, "Refractive Index of Acetone-Water mixture at different concentrations", American International Journal of Research in Science, Technology, Engineering & Mathematics 20(1), 77 (2017). CrossRef T.H. Barnes, K.Matsumoto, T. Eiju, K. Matsuda, N. Ooyama, "Grating interferometer with extremely high stability, suitable for measuring small refractive index changes", Appl. Opt. 30, 745 (1991). CrossRef B. W. Grange, W. H. Stevenson, R. Viskanta, "Refractive index of liquid solutions at low temperatures: an accurate measurement", Applied Optics 15(4), 858 (1976). CrossRef P. Hlubina, "White-light spectral interferometry with the uncompensated Michelson interferometer and the group refractive index dispersion in fused silica", Optics Communications 193(1-6), 1 (2001). CrossRef P. Hlubina, W. Urbanczyk, "Dispersion of the group birefringence of a calcite crystal measured by white-light spectral interferometry", Meas. Sci. Technol. 16(6), 1267 (2005). CrossRef P. Hlubina, D. Ciprian, L. Knyblova, "Direct measurement of dispersion of the group refractive indices of quartz crystal by white-light spectral interferometry", Optics Communications 269(1), 8 (2007). CrossRef S. R. Kachiraju, D. A. Gregory, "Determining the refractive index of liquids using a modified Michelson interferometer", Optics & Laser Technology 44(8), 2361 (2012). CrossRef F. Gladstone, D. Dale, "XXXVI. On the influence of temperature on the refraction of light", Philos. Trans. R. Soc. 148, 887 (1858). CrossRef D.F.J. Arago, J.B. Biot, Mem. Acad. Fr. 15, 7 (1806). CrossRef Kurtz S S and Ward A L J, "The refractivity intercept and the specific refraction equation of Newton. I. development of the refractivity intercept and comparison with specific refraction equations", Franklin Inst. 222, 563-592 (1936). CrossRef K. Moutzouris, M. Papamichael, S. C. Betsis, I. Stavrakas, G. Hloupis, D. Triantis, "Refractive, dispersive and thermo-optic properties of twelve organic solvents in the visible and near-infrared", Appl. Phys. B 116, 617 (2013). CrossRef S. Kedenburg, M. Vieweg, T. Gissibl, H. Giessen, "Linear refractive index and absorption measurements of nonlinear optical liquids in the visible and near-infrared spectral region", Opt. Mater. Express 2(11), 1588 (2012). CrossRef

A series of platinum-zeolite based catalysts were prepared by reduction of Pt-salt with a methanol-water mixture using individual HY-zeolite or its modified composites both as protective agents and catalyst supports. The prepared composites have been tested as catalysts in n-C10-hydroconversion reaction in the range of temperature 180–270 °C and at atmospheric pressure. Different parallel and consecutive isomerization and cracking reactions take place in hydroconversion of n-decane over prepared catalysts producing different mono- and multi-isomers and cracked products. The impact of the temperature and conversion degree to the distribution of hydroconversion products has been studied. Special attention was paid to synthesis of high-octane fuel components from n-decane.

The mole fraction solubility of phenacetin (PNC) in methanol + water binary solvent mixtures at 298.15 K was determined along with density of the saturated solutions. All these solubility values were correlated with the Jouyban–Acree model. Preferential solvation parameters of PNC by methanol (δx1,3) were derived from their thermodynamic solution properties using the inverse Kirkwood–Buff integrals (IKBI) method. δx1,3 values are negative in water-rich mixtures but positive in methanol mole fraction of >0.32. It is conjecturable that in the former case the hydrophobic hydration around non-polar groups of PNC plays a relevant role in the solvation. The higher solvation by methanol in mixtures of similar cosolvent compositions and methanol-rich mixtures could be explained in terms of the higher basic behaviour of methanol.

Equilibrium solubility of sodium naproxen (Na·NAP), procaine hydrochloride (PC·HCl), and lysine clonixinate (Lys·Clon), was determined in methanol + water mixtures at 298.15 K. Mole fraction solubility of Na·NAP increases from neat water ( x 3 = 1.71 × 10 − 2 ) to reach a maximum in the mixture with w 1 = 0.90 ( x 3 = 5.05 × 10 − 2 ); the solubility of PC·HCl increases from neat water ( x 3 = 9.68 × 10 − 2 ) to reach a maximum in the mixture with w 1 = 0.20 ( x 3 = 0.1032); whereas, the solubility of Lys·Clon increases from neat water ( x 3 = 3.54 × 10 − 2 ) to reach a maximum in the mixture with w 1 = 0.60 ( x 3 = 6.33 × 10 − 2 ). The generated solubility data are mathematically represented by using the Jouyban-Acree model with very good error level (average of 1.2% for molar solubilities). In addition, the apparent specific volumes at saturation of these drugs were also calculated in all the mixtures under study using the measured densities of the saturated solutions. In this way, the average apparent volumes at saturation in these mixtures could be considered as follows: 0.699 cm 3 g − 1 for Na·NAP, 0.821 cm 3 g − 1 for PC·HCl, and 0.730 cm 3 g − 1 for Lys·Clon.

Dynamical features of hydrogen bonds in methanol–water mixtures have been analysed in terms of lifetime in the wide range of conditions, including supercritical states, using a molecular dynamics simulation with flexible potential models. Hydrogen bond characteristics in methanol–water mixtures were investigated by considering the combination of molecular species and donor–acceptor of hydrogen-bonded molecules. The hydrogen bond lifetimes mainly depend on temperature, and those in supercritical condition were about 1/10th of that at ambient condition. Focusing on the composition dependence of the hydrogen bond lifetime, the unique behaviour of that resulting from hydration structure was observed. Moreover, the molecular combination, which showed the largest hydrogen bond lifetime, was different for ambient and high temperature and high pressure conditions. The relationship between hydrogen bond lifetime and molar volume was also calculated to discuss the hydrogen bond lifetime in terms of the coll...

Viscosities and self-diffusion coefficients of methanol–water mixtures were calculated via molecular dynamics simulation from 298.2 to 476.2 K and at pressures up to 40 MPa. The periodic perturbation method (non-equilibrium molecular dynamics) and the Green-Kubo method with three-site flexible potential models were adopted for evaluating the viscosities and the diffusion coefficients, respectively. The calculated viscosities and diffusion coefficients of methanol–water mixtures agreed qualitatively with literature experimental values. The three-site flexible potential models used in this study provided similar performance to the previous studies that used rigid models. Results correlated with the Stokes–Einstein relation show the possibility that the effective hydrodynamic radii were approximately constant for the studied condition and might be little affected by the clathrate-type structure at lower methanol compositions.

A gravimetric method was used to determine the solubility of maltitol in five pure solvents, methanol–water mixtures, and ethanol–water mixtures at different temperatures from 298.15 to 323.15 K. At a given temperature, the solubility of maltitol in the five pure solvents follows this order: 2-propanol < ethanol < methanol < DMF < water. Compared with the modified Van’t Hoff equation, the modified Apelblat equation presents a better consistence with the solubility of maltitol in different pure solvents. The solubility of maltitol increases with rising temperature, but decreases with the increase of the initial mole fraction of methanol or ethanol. It is found that the modified Apelblat equation can give better correlation results in methanol–water mixtures and ethanol–water mixtures than the combined nearly ideal binary solvent/Redlich–Kister equation or the two kinds of Jouyban–Acree models.

Two bipyridinium-bearing Cu(II) coordination polymers, [Cu(BCbpy)(ox)(H 2 O)]·H 2 O ( 1 ) and [Cu 2 (BCbpy) 2 (ox) 2 ]·3H 2 O·DMF ( 2 ), have been synthesized and structurally characterized. Upon solvent modulation, the structure transformation from a closely-packed 1D chain to a 2D laminar network with parallelogram-shaped channels can be achieved. More interestingly, the charge separated skeleton of BCbpy ligand incorporated in compound 2 makes the pore space polarized, endowing it with different adsorption abilities for methanol, water and ethanol vapors.

C36H33NO10, monoclinic, P21/c (no. 14), a = 14.113(7) Å, b = 17.883(9) Å, c = 12.724(7) Å, β = 108.218(9)°, V = 3050(3) Å3, Z = 4, R gt(F) = 0.0788, wR ref(F 2) = 0.1967, T = 293 K.

C62H80Mn2N16O18, triclinic, P1̅ (no. 2), a = 11.3232(10) Å, b = 12.879(2) Å, c = 13.035(2) Å, α = 84.854(17)°, β = 69.317(16)°, γ = 73.929(13)°, V = 1708.8(4) Å3, Z = 1, R gt(F) = 0.0320, wR ref(F 2) = 0.0860, T = 113 K.

Mechanical mixtures of platinum-loaded and bare anatase, rutile and brookite TiO2 polymorphs were studied in the photocatalytic production of hydrogen (PHER) in methanol-water slurries. Mixtures of TiO2 and Pt/TiO2 materials show non-additivity of catalytic properties as a function of the nature of titania polymorphs involved. Addition of bare rutile or brookite to Pt/anatase leads to a drop of the PHER rate. By contrast, addition of bare anatase improves PHER activity of both Pt/rutile and Pt/brookite. These observations are coherently explained by directional transfer of long-live stored electrons between the particles in suspensions. Hydrogen release in the dark after addition of Pt/TiO2 to pre-illuminated bare TiO2 give evidence that such transfer is fast and have a pronounced directionality. The accumulated electrons are preferentially transferred from anatase to rutile or to brookite. A simple mechanistic framework and a phenomenological kinetic model are proposed that correctly describe the observed variations of PHER rates.

Raman spectroscopy was used for rapid in-situ measurement of alcohols in ethanol-methanol-water ternary systems. Mass fractions of the individual components were determined using calibration curves for binary systems of ethanol-water, methanol-water, and ethanol-methanol. Calibration curves were constructed by calculating the ratio of the Raman peak intensity of a component and that of an external standard (acetonitrile). Assuming additivity of the spectra, simultaneous equations were written, and mass fractions of ethanol, methanol, and water in the ternary solutions were determined by solving the system of equations through calculating an inverse matrix. The relative errors between the mass fractions obtained from the Raman spectra and those obtained from mass measurements were

In the current study, four Onobrychis species, O. albiflora Hub.-Mor., O. argyrea Boiss. subsp. argyrea Boiss., O. galegifolia Boiss., and O. tournefortii (Willd.) Desv. were collected from Anatolia to be evaluated for their antidiabetic activities. Methanol water extracts of the aerial parts were used for experiments. An alloxan-induced diabetic mice test model was used. Phytochemical analysis of the tested extracts was investigated using the HPLC method. The highest activity was observed with treatment of O. albiflora aerial part extract. Significant decrements were detected in the blood glucose levels as follows: 180.83±47.48 and 252.83±50.47mg/dL at 100 mg/kg and 200 mg/kg doses of O. albiflora, respectively, when compared to the isotonic saline solution control group, eliciting a blood glucose level of 494.20±27.32. Among the tested standard compounds, rutin and isoquercetin were detected in the examined species. The highest amount of rutin (1.1981±0.0017%) and isoquercetin (0.7318±0.0197%) were found in O. albiflora and O. argyrea subsp. argyrea, respectively. Antidiabetic activities of the tested Onobrychis species seem to indicate a possible correlation with their rutin and isoquercetin contents. Therefore, rutin and isoquercetin may be the antidiabetic compounds that contribute to the antidiabetic activity of the tested Onobrychis species.

Steady-state and time-resolved fluorescence techniques were used to study the excited-state proton transfer (ESPT) from an irreversible photoacid, 1-naphthol-3,6-disulfonate (1NP36DS), to methanol-water mixtures. We found that at χ

Celery fraction research (Apium graveolens L.) was carried out to determine the ability of the sedation effect of celery fraction compared to celery extracts which have been known to have the ability to effect the previous sedation. This study aims to find out which fraction has the best sedation effect. This study was an experimental study with a Completely Randomized Design (CRD) consisting of 5 treatments and 5 replications. Test animals divided into 5 treatment groups namely negative control group (CMC Na 1%), celery extract group 200mg /kg and 3 treatment groups n-hexane fraction, ethyl acetate, and methanol water fraction with a dose of 200 mg /kg . The sedation effect test was carried out using the Traction Test and Fireplace Testmethods. Quantitative data observed were the length of time the mice fell and the length of time the mice went out of the heated tube/glass. The results of the analysis showed that the celery fraction had a better sedation effect than the extract, and the methanol water fraction 200 mg/kg was the most effective fraction in causing sedation effects.

The title compound, which crystallized as a methanol and water solvate, C24H41NO5·CH4O·H2O, was obtained by heterologous expression of the brasilicardin gene cluster in the bacterium Amycolatopsis japonicum. In the crystal, the components are linked by numerous hydrogen bonds, generating a three-dimensional network.