Novel enhancement of the reducing ability of ytterbium diiodide by irradiation with near-UV light

Irradiation with near-UV light, dramatically enhances the reducing ability of ytterbium diiodide (YbI₂). Organic bromides, iodides, tosylates, and tellurides are reduced efficiently by a YbI₂-hv system, while these can not be reduced with YbI₂ in the dark.     

Selective lumping finite element method for nearshore current

A finite element method for the analysis of nearshore current, which is one of the principal currents in coastal seas, is presented in this paper. Because the nearshore current is induced by the variable distribution of the surface waves, it is necessary to analyse two main characteristics of the wave, i.e. direction and height. The current can be computed using the resulting wave characteristics. The present method makes it possible to employ procedures for which the same methods of solution are applicable for all basic equations of wave direction, height and current flow. The linear interpolation function is used for the discretization of spatial variables and a selective lumping two step explicit scheme is employed for the numerical integration in time. The numerical solutions obtained are compared with analytical, experimental and observed ones. From these comparative studies, it is concluded that the present finite element method provide a useful tool for the analysis of nearshore current.     

Chemoenzymatic synthesis of naturally occurring benzyl 6-O-glycosyl-beta-D-glucopyranosides

Direct beta-glucosidation between benzyl alcohol and D-glucose (5) using the immobilized beta-glucosidase from almonds with the synthetic prepolymer ENTP-4000 gave a benzyl beta-D-glucoside (1) in 53% yield. The coupling of the benzyl beta-D-glucopyranoside congener (8) derived from 1 with phenyl 2,3,4-tri-O-acetyl-1-thio-beta-D-xylopyranoside (9), ethyl 2,3,4-tri-O-acetyl-1-thio-alpha-L-rhamnopyranoside (13), and 2,3,4-tri-O-acetyl-alpha-L-arabinopyranosyl bromide (15) afforded 10, 14, and 16, respectively, as coupled products. Deprotection of 10, 14, and 16 provided the synthetic benzyl beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranoside (2), benzyl alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (3), and benzyl alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside (4), respectively.     

Multiple level finite element analysis and its applications to tidal current flow in Tokyo Bay

A finite element method for the analysis of a one level and a multiple level current flow is presented. The basic equations can be derived from the three-dimensional Navier-Stokes equations under the shallow water assumptions. The standard finite element method has been introduced using the linear interpolation function based on a triangular finite element. For each level, the finite element subdivisions are not required to be coincident. To integrate the discretized equations numerically in time, an improved two step explicit scheme is employed. The multiple level finite element method is applied to a tidal flow analysis of Tokyo Bay.The multiple level tidal flow analysis is performed at the entrance channel of Tokyo Bay. The density of water is assumed to be constant for each level. The vertical profiles of the numerical velocity are compared with those of the observed velocity. The flow directions and the order of velocity are both well in agreement with the observed data. The tidal flow pattern in Tokyo Bay has been shown to be expressed by the multiple level flow assuming that the density of seawater is levelwise constant.The numerical tidal flow computation of Tokyo Bay carried out using a one level model is compared with observed data. The one level numerical values will be used to specify the boundary conditions for the multiple level analysis. Both numerical and observed results correspond extremely well in this computation. The two dominant circulated residual flows have been computed, and they coincide with the observed facts.     

Two-dimensional wave run-up analysis by selective lumping finite element method

A new finite element technique for the analysis of wave run-up is presented in this paper. In this finite element approach, the movement of the shoreline is expressed by that of the nodal points at the wave front, and an auto mesh generation technique is effectively used. The present method is tested by the comparison with the experimental result of a channel with uniform slope, and two numerical examples are reported to show the efficiency of this method. As a final example, the tsunami run-up caused by the 1983 Nihonkai-Chubu earthquake is analysed and compared with actual records of the flooded area.