Comparison between centrifugal and vertical vibro-compaction of high-lifted decomposed weathered granite sandy soil using a tracked vehicle

The aim of this research was to develop a new vibro-compaction machine by comparing experimentally and theoretically the effects of a tracked vehicle of total weight 9.8 kN mounted with a centrifugal or vertical oscillator on a high lifted decomposed weathered granite sandy soil. By measuring the amount of sinkage of the terrain surface, the dry density distribution with depth, the normal earth pressure distribution with depth, and the vertical and horizontal acceleration distribution with depth, the compacting effect of centrifugal and vertical vibro-tracked vehicles on the increment of dry density in a deep soil stratum were compared for a frequency of about 54 Hz. It was observed that the centrifugal vibro-tracked vehicle showed a 25% increase in the final amount of sinkage and a 11.3% increase in the maximum dry density of compacted soil compared to the vertical vibro-tracked vehicle. We believe that the centrifugal vibro-tracked vehicle can be shown from the analysis of the stress and acceleration propagation to be a better compaction machine at a high frequency of oscillation for a high lifted soil stratum when compared to conventional vertical vibro-tracked vehicles.     

Numerical investigation of laminar cross-flow non-premixed flames in the presence of a bluff-body

A knowledge of flame stability regimes in the presence of cylindrical bluff-bodies of various dimensions is essential to design non-premixed burners. The reacting flow field in such cases is reported to be three-dimensional and unsteady. In the literature, only a few experimental investigations with limited measurements are available. Therefore, in this work, a detailed numerical study of laminar cross-flow non-premixed methane–air flames in the presence of a square cylinder is presented. The flow, temperature, species and reaction fields have been predicted using a comprehensive transient three-dimensional reacting flow model with detailed chemical kinetics and variable thermo-physical properties, in order to get a good insight into the flame stabilisation phenomena. Further, analyses of quantities such as local equivalence ratio, cell Damköhler number, species velocity, net consumption rate of methane, which are not easily obtained through experiments even with detailed diagnostics, have been carried out. The influence of the flow field due to varying inlet velocity of the oxidiser, in the presence of the bluff-body, on flame anchoring location has been analysed in detail. Local equivalence ratio contours obtained from non-reacting flow calculations are seen to be quite useful in analysing the mixing process and in the prediction of flame anchoring locations when the flames are not separated. Cell Damköhler number has been calculated using cell size, species velocity of the fuel, which is a derived quantity, and the net reaction rate of the fuel. The flame zone, which is customarily inferred from the contours of temperature, CO and OH, is also shown to be predicted well by the contour line corresponding to a Damköhler number equal to unity. The net reaction rate of CH₄ and the net rates of two dominant reactions, which consume methane, show clearly the variation in the flame anchoring locations in these three cases. Further, the three-dimensionality of these flames are analysed by plotting the mean temperature contours in y–z planes. Finally, the unsteadiness in the separated flame case is analysed.     

Simultaneous quantification of ambrisentan,macitentan and sitaxentan in human plasma using UPLC–MS/MS

Endothelin receptor antagonists (ERAs) such as, ambrisentan, macitentan and sitaxentan are primarily used for the treatment of pulmonary arterial hypertension. Considering the rise in endothelin in pre-eclampsia, ERAs may also be useful in its treatment. To evaluate the pharmacokinetics of ERAs, a rapid ultra-performance liquid chromatography tandem mass spectrometry method was developed and validated to determine the concentration of ambrisentan, macitentan and sitaxentan in human plasma. Plasma samples were treated with methanol to induce protein precipitation. A chromatographic separation was performed on a C₁₈ column using a gradient of methanol–water containing 0.1% formic acid and 0.013% ammonium acetate and a flow rate of 0.5 ml/min. Multiple reaction monitoring was used for quantification. This method was validated in a linear range of 20.28–2028 μg/l for ambrisentan, 4.052–405.2 μg/l for macitentan and 205.4–10 270 μg/l for sitaxentan. The method was successfully validated according to US Food and Drug Administration guidelines to determine the concentrations of macitentan, ambrisentan and sitaxentan in human plasma. This method is now being used for study samples and clinical patient samples.     

Periodic solutions of the Navier�CStokes equations with the inhomogeneous time-dependent boundary data under the general flux condition

We consider the initial boundary value problem to the Navier–Stokes equations in a bounded domain with the inhomogeneous time-dependent data b(t) ? H^1/2(?W){\beta(t) \in H^{1/2}(\partial\Omega)} under the general flux condition. We establish a reproductive property for weak solutions of the Navier–Stokes equations. Here, the reproductive property is regarded as the generalization of the time periodicity. As an application, we can prove the existence of periodic weak solutions.     

Asymmetric induction in an intramolecular [2+2] photocycloaddition within chirally modified zeolite supercages

Photoirradiation of 1-cyano-2-(5-methyl-2-oxa-4-hexenyl)naphthalene, included in NaY zeolites along with chiral inductors, such as diethyl tartrate or phenylalaninol, gives an intramolecular [2+2] photocycloadduct with a maximum 15% ee. The degree of enantioselectivity was found to depend on the Si/Al ratio, the nature of the cations in the zeolites, the structure of the chiral inductors, and the molar ratio of substrate and chiral inductors.     

Yamadazyma Farinosa IFO 10896-Mediated Reduction of 4,4-Dimethoxy-2-Butanone as the Key-Step for the Preparation of 1,3-Diols with Unsymmetrical Substituents

(R)-4,4-Dimethoxy-2-butanol was prepared with the action of Yamadazyma farinosa IFO 10896 on 4,4-dimethoxy-2-butanone, and subsequently converted to (2R,4R)- and (2R,4S)-isomers of 6-hepten-2,4-diol by the treatment with allyl bromide and indium in aqueous solution.