Ebulliometric determination and prediction of (vapor + liquid) equilibria for binary and ternary mixtures containing alcohols (C1–C4) and dimethyl carbonate

(Vapor + liquid) equilibrium (VLE) data for a ternary mixture, namely {methanol + propan-1-ol + dimethyl carbonate (DMC)}, and four binary mixtures, namely an {alcohol (C₃ or C₄) + DMC}, containing the binary constituent mixtures of the ternary mixture, were measured at p = (40.00 to 93.32) kPa using a modified Swietoslawski-type ebulliometer. The experimental data for the binary systems were correlated using the Wilson model. The Wilson model was also applied to the ternary system to predict the VLE behavior using parameters from the binary mixtures. The modified UNIFAC (Dortmund) model was also tested for the predictions of the VLE behavior of the binary and ternary mixtures. In addition, the experimental VLE data for the ternary and constituent binary mixtures were correlated using the extended Redlich–Kister (ERK) model, which can completely represent the azeotropic points. For the ternary system, a comparison of the experimental and the predicted or correlated boiling points obtained using the Wilson and ERK models showed that the ERK model is more accurate. The valley line, i.e., the curve which divides the patterns of vapor–liquid tie lines, was found in the (methanol + propan-1-ol + DMC) system. This valley line could be represented by the ERK model. Finally, the composition profile for simple distillation of this ternary mixture was obtained by analysis of the residue curves from the estimated Wilson parameters of the constituent binary mixtures.     

Heat‐Induced Morphological Transformation of Supramolecular Nanostructures by Retro‐Diels–Alder Reaction

Controlling the morphology of supramolecular nanostructures in response to external stimuli is an important challenge in the development of functional soft materials. Here we show that a morphological transformation from 2D nanosheets to a network of 1D nanofibers is triggered by heating, which induces molecular conversion of a bolaamphiphile to a hydrogelator by means of a retro‐Diels–Alder reaction, thereby producing a new heat‐set supramolecular hydrogel. We anticipate that our design will be a starting point for more sophisticated supramolecular systems that integrate the thermodynamics of molecular assembly and the kinetics of chemical reactions to create complex supramolecular nanostructures.     

Morphology and mechanical properties of ultrahigh-molecular-weight polyethylene films prepared from solutions in mixtures of diphenyl and diphenylether as co-solvent

In an attempt to check solvent dependence of drawability of ultra high-molecular-weight polyethylene films, gels were prepared from diphenyl/diphenylether solution, which is well known as -solvent. The content of diphenyl in the mixed solvent was chosen to be 25 wt%. Rapid gelation occurred when the solution had been cooled down to temperature lower than 147°C. The gel shrunk drastically with the further decrease of temperature and formed a bulk specimen. The maximum draw ratio was 20 and the corresponding Young's modulus reached 27 GPa. The value of Young's modulus was higher than the maximum value of melt film stretched up to 30 times, but it was much lower than the value of film which was prepared by gelation from decalin solution and was elongated up to 300. Thus, it turned out that the drastic shrinkage in the process of rapid gelation hampers a suitable level of the entanglement mesh that effectively transmits the drawing force.     

A novel method for the assay of alpha-glucosidase inhibitory activity using a multi-channel oxygen sensor.

The quantification of glucose by using a multi-channel dissolved oxygen (DO) meter (DOX96) with immobilized glucose oxidase (GOD) and mutarotase (MUT) was performed. An evaluation of the inhibitory activities for alpha-glucosidase (AGH) by modifying our batch-type pseudo-in vivo assay system [Oki et al.; Biol Pharm. Bull., 2000, 232, 1084] was also performed using a DOX96. When 45 U/well GOD and 18.75 U/well MUT were immobilized on the surface of a gelatin membrane on the electrodes, the response shown by the decrease percent of DO (%) obtained with 8 electrode wells in the same row was linear with the glucose concentration up to 3.3 mM and a correlation coefficient larger than 0.9. To estimate the AGH inhibitory activity, AGH-immobilized Sepharose supports in the well of a silent screen plate were used. The IC50 values of acarbose and 1-deoxynojirimycin, a medicinal inhibitor for diabetes, were 0.70 +/- 0.08 microM and 0.40 +/- 0.13 microM, respectively, and coincided well with those by a pseudo-in vivo assay.     

New synthetic reaction by electrolysis malonic acid as a ketone synthon

Malonic acid derivatives(gem-dicarboxylic acids) were converted to the corresponding ketones by the electrolysis. The reaction was employed for the synthesis of jasmones.     

Phase transition in metal hexammine complexes—i the I.R. spectra of Ni(NO3)26NH31

Far i.r. spectra of Ni(NO₃)₂6NH₃ were recorded above and below the order-disorder phase transition at T_c = 243 K. The results are compared to the spectra of the isomorphous crystal NiCl₂6NH₃, which has no transition in the same temperature range. The antisymmetric stretching vibration of the ammonias shows a broken degeneracy below T_c for Ni(NO₃)₂6NH₃. No broken degeneracy was observed in the nickel-nitrogen vibration of the |Ni(NH₃)₆|²⁺ clusters. The discussion of our results lends support to the assumption that the phase transition is due to the collective freezing of the degrees of rotation of the ammonias.     

Determination and correlation of binary vapor-liquid equilibrium data

The Chao modification of the Redlich-Kister equation for correlating liquid activity coefficients is further modified to facilitate the evaluation of the constants. The determination of liquid activity coefficients at infinite dilutions by means of an ebulliometer with the consideration of vapor hold-up in the condenser is proposed. Both of these proposals are equally applicable to isothermal data and to isobaric data.For the purpose of illustration, vapor-liquid equilibrium data for the binary system acetone-methanol together with the azeotropic point and the liquid activity coefficients at infinite dilutions were determined at 760 Torr. The validity of the correlated data was confirmed with the enthalpies of mixing data at saturation, available in the literature.     

Electrical CT image reconstruction technique for powder flow in petroleum refinery process

A new reconstruction method called sampled pattern matching (SPM) was applied to the image reconstruction of an electrical capacitance computed tomography in powder flow in a vertical pipe for petroleum refinery process. This new method is able to achieve stable convergence without the use of an empirical value. Experiments were carried out using fluid catalytic cracking (FCC) catalysts as powder with two air volume flow rates and four powder volume flow rates to measure the capacitance of a pipe cross section. The SPM method is compared with conventional methods in terms of volume fraction, residual capacitance, and correlation capacitance. Overall, the SPM method proved superior to conventional methods without any empirical value because SPM achieves accurate reconstruction by using an objective function that is calculated as the inner product calculation between the experimental capacitance and the reconstructed image capacitance.     

Synthetic Studies on Vitamin D Analogues VI. A New Synthesis of 25-Hydroxycholesterol from Lithocholic Acid

The conversion of lithocholic acid (1) into 25-hydroxycholesterol (10) via methyl 3β-hydroxy-5-cholenate (6) is described.