Numerical analysis of finite amplitude motion of waves and a moored floating body under severe storm conditions

The motion of a moored floating body under the action of wave forces, which is influenced by fluid forces, shape of the floating body and mooring forces, should be analysed as a complex coupled motion system. Especially under severe storm conditions or resonant motion of the floating body it is necessary to consider finite amplitude motions of the waves, the floating body and the mooring lines as well as non-linear interactions of these finite amplitude motions. The problem of a floating body has been studied on the basis of linear wave theory by many researchers. However, the finite amplitude motion under a correlated motion system has rarely been taken into account. This paper presents a numerical method for calculating the finite amplitude motion when a floating body is moored by non-linear mooring lines such as chains and cables under severe storm conditions.     

Approximate Solution of the Saha Equation — Temperature as an Explicit Function of Particle Densities

The Saha equation for a plasma in thermodynamic equilibrium (TE) is approximately solved to give the temperature as an explicit function of population densities. It is shown that the derived expressions for the Saha temperature are valid approximations to the exact solution. An application of the approximate temperature to the calculation of TE plasma parameters is also described.     

Almost Hermitian structures induced from a Kähler structure which has constant holomorphic sectional curvature

We obtain a non-Kähler almost Hermitian manifold of constant holomorphic sectional curvature by changing the almost complex structure in a Kähler manifold of constant holomorphic sectional curvature.

     

X-ray damage characterization in BaLiF3,KMgF3 and LiCaAlF6 complex fluorides

Two-inch sized KMgF₃,BaLiF₃ and LiCaAlF₆ (LiCAF) single crystals were grown by the Czochralski method under a CF₄ atmosphere. X-ray irradiation was used to carry out a comparative study of induced optical absorption phenomena and colour centre creation in the ultra-violet and visible spectral regions. The integral of the induced absorption spectra is significantly lower in LiCAF with respect to the other studied materials. It is found that the amplitude of the F-absorption band is suppressed more than a factor of 3 by Mg-doping. For Mg-doped crystals, the optimum doping concentration is about 0.2 mol% of Mg²⁺.     

Reaction kinetics and pathway of hydrothermal decomposition of aspartic acid

The kinetics and pathway of hydrothermal decomposition of aspartic acid were studied using a continuous‐flow tubular reactor. The reaction was carried out in the temperature range of 200–260°C and at a pressure of 20 MPa. Deamination was the primary reaction, indicated by the presence of significant amount of ammonia, fumaric acid, or maleic acid in the products. Other reaction products were pyruvic acid, malic acid, and traces of succinic and lactic acid. Traces of alanine were also detected, showing the possibility of decomposing high‐molecular weight amino acids to obtain simple amino acids such as glycine or alanine. Results on the effect of reaction parameters demonstrated that decomposition of aspartic acid is highly temperature dependent under hydrothermal conditions. For a slight temperature difference of 60°C (from 200 to 260°C), the first‐order reaction rate constants of 0.003 significantly increased to 0.231 s^?1. The activation energy was 144 kJ/mol, as calculated by the Arrhenius equation. No significant effect was exhibited by other reaction parameters such as pH and pressure. The results are useful in controlling the hydrolysis of proteinaceous materials toward high yield of aspartic acid under hydrothermal conditions. © 2007 Wiley Periodicals, Inc. 39: 175–180, 2007     

The effect of surface modification with silane coupling agent on suppressing the photo-catalytic activity of fine TiO2 particles as inorganic UV filter

The effect of surface modification with 3-aminopropyltriethoxysilane (APTES) and n-propyltriethoxysilane (PTES) on photo-catalytic activity and UV-shielding ability of fine TiO₂ particles were investigated. The number of surface groups (N_R) [nm⁻²] which shows the density of modifier on TiO₂ surface was calculated from the results of elemental analysis and BET measurement. The modified samples of which N_R are different were obtained by changing the concentration of modifier. When the photo-catalytic activity and UV-shielding ability of modified samples were evaluated, it was found that APTES was more effective modifier than PTES to obtained samples with low photo-catalytic activity and high UV-shielding ability. This is probably because the adsorption mechanisms on TiO₂ surface between modifiers were different and N_R is a key factor to control the performances of fine TiO₂ particles. The result of zeta potential showed that surface character of modified samples was varied by changing N_R. It suggested from these results that N_R affected the photo-catalytic activity and UV-shielding ability because N_R changed surface character of modified samples.     

Imprinting by hot embossing in polymer substrates using a template of silica glass surface-structured by the ablation of LIBWE method

Laser-induced backside wet etching (LIBWE) of silica glass plates was performed to fabricate an imprinting template for hot embossing in polymer substrates such as polystyrene and silicone resin. Well-defined inverse surface-micropatterns of gratings and grid arrays on the substrates were produced by the hot embossing using a surface-structured silica glass as the template. These results indicate that the LIBWE method allows us to generate robust glass molding tools that exhibit the inverse shapes of the intended microstructures. PACS 52.38.Mf; 68.47.Mn; 81.05.Kf; 81.05.Lg; 83.50.Uv     

Breakage of λ-DNA by inorganic tin and organotin compounds as environmental pollutants

In proportion to the environmental pollution problems caused by organotin compounds, the genotoxicities of tin compounds in the environments have become of interest so as to estimate their safety in recent years. In this work, isolated λ-DNA (double-strand DNA) was incubated with inorganic tin(II) and tin(IV) and five organotin compounds [n-butyltin trichloride, di(n-butyltin) dichloride, methyltin trichloride, dimethyltin dichloride and trimethyltin chloride] in reaction systems both with and without hydrogen peroxide (H₂O₂) content. The tin compounds tested in this study did not induce DNA breakage in the absence of hydrogen peroxide. Divalent inorganic tin (SnCl₂) and tetravalent inorganic tin (SnCl₄) caused DNA breakage in the presence of hydrogen peroxide (10 mM), and the DNA damage activity of inorganic tin was much more potent in divalent inorganic tin (SnCl₂) than in tetravalent inorganic tin (SnCl₄). Divalent inorganic tin (SnCl₂) induced DNA breakage in a concentration-dependent fashion at concentrations greater than 0.1 mM of SnCl₂ in the presence of hydrogen peroxide (10 mM). DNA breakage was not caused by n-butyltin compounds and methyltin compounds either in the presence or in the absence of hydrogen peroxide.     

Nuclearity of a nonnegative definite integral kernel on a separable metric space

The aim of this paper is to characterize the nuclearity of an integral operator, defined by a continuous non-negative definite square integrable kernel on a separable metric space, in terms of the integrability of the trace of the kernel function. Nuclearity here plays a role forU-statistics.