Simulation of shockwave propagation with a thermal lattice Boltzmann model

A two‐dimensional 19‐velocity (D2Q19) lattice Boltzmann model which satisfies the conservation laws governing the macroscopic and microscopic mass, momentum and energy with local equilibrium distribution order O(u⁴) rather than the usual O(u³) has been developed. This model is applied to simulate the reflection of shockwaves on the surface of a triangular obstacle. Good qualitative agreement between the numerical predictions and experimental measurements is obtained. As the model contains the higher‐order terms in the local equilibrium distribution, it performs much better in terms of numerical accuracy and stability than the earlier 13‐velocity models with the local equilibrium distribution accurate only up to the second order in the velocity u. Copyright © 2003 John Wiley & Sons, Ltd.     

Study on organic pollution parameters for dyes and dyeing auxiliaries

Analytical and Bioanalytical Chemistry -     

Complete removal of paint from metal surface by ablation with a TEA CO2 laser

For high-speed metal surface cleaning, we applied TEA CO₂ laser pulses to ablate painted materials on metal surfaces and examined the efficiency of removal under different surface and irradiation conditions. Surfaces treated with a line-focused laser beam were analyzed with an energy dispersive X-ray analyzer and inspected with optical microscopic observation. Although paints were selectively ablated from the metal surface, the cleaning efficiency was found to depend on surface conditions of substrates. An application of a small amount of dimethyl formamide was effective for completely removing of resin without scorching the surface.     

Nucleon transfer in highly mass-asymmetric reaction systems between197au and relatively light projectiles in the energy region below 10 MeV/u

Mechanisms of heavy-ion induced nuclear reactions in mass-asymmetric systems were studied by focusing on the nucleon transfer reaction. Excitation functions and projected mean recoil ranges for the target-like products in³⁷-,¹⁶O-,¹⁴N-, and¹²C-induced reactions on¹⁹⁷Au were measured by means ofγ-ray spectrometry. The energy range studied was near the Coulomb barrier of the systems with incident energies below 10 MeV/u. Nucleon transfer reactions were discussed by distinguishing the products from quasi-elastic transfer (QET) and those from deep inelastic transfer (DIT). The tendency towards equilibration of theN/Z value and the energy damping, which are the characteristic features of DIT, were found in the production of Au isotopes. Observations are consistent with the generally accepted concept that QET takes place along a trajectory near the Coulomb trajectory. QET was made to be connected with the interaction radius and most of the cross section ratios were reproduced well by an extended tunneling model.     

Pulsar magnetic moment decay due to radiation damping and the pulsar in SN 1987 A

Summary A new theory is proposed to account for the decay of the pulsar magnetic moment in terms of radiation damping mechanism. Detailed comparisons with the up-to-date pulsar observations are made. The theory is then applied to binary radio pulsars thereby resolving the dilemma concerning the ages and the magnetic fields of the pulsars PSR 0655+64 and PSR 1855+09. Finally a prediction is made concerning the period and period derivative of the pulsar in SN 1987 A.

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Riassunto Si propone una nuova teoria per spiegare il decadimento dell’impulso magnetico delle pulsar in termini di un meccanismo di smorzamento delle radiazioni. Si fanno confronti dettagliati con osservazioni attuali di pulsar. Si applica quindi la teoria a radio pulsar binarie risolvendo cosí il dilemma che concerne le età e i campi magnetici delle pulsar PSR 0655+64 e PSR 1855+09. Infine si fa una previsione sul periodo e sulla derivata del periodo della pulsar nella SN 1987 A.

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Резюме Предлагается новая теория для оббяснения уменьшения магнитного момента пульсара в терминах механизма радиационного затухания. Проводятся подробные сравнения с наблюдениями пульсаров. Затем эта теория применяется к двойным радио-пульсарам, чтобы решить дилемму, касаюшуюся возрастов и магнитных полей пульсаров PSR 0655+64 и PSR 1855+09. В заключение делаются предсказания относительно периода и производной периода для пульсара в SN 1987 A.

     

The first x-ray structure determination of a -phosphaethylene: -2-phenyl-1-(2,4,6-tri-t-butylphenyl)phosphaethylene

The sterically protected -phosphaethylene, -2-phenyl-1-(2,4,6-tri-t-butylphenyl)phosphaethylene (1-Z), was analyzed by X-ray crystallography.     

Reaction cross sections and radii of A=17 and A=20 isobars

Reaction cross sections and root-mean-square (rms) radii of A=17 and A=20 isobars are calculated by using a simplified Glauber model and spherical and deformed Hartree-Fock (HF) wave functions. The small separation energy effect is discussed on the reaction cross sections of A=17 isobars and possible proton halo in ¹⁷Ne by using modified spherical HF wave functions. The calculated rms mass radii of A=20 isobars are increased appreciably by the deformation effect and show a similar irregular pattern as a function of the isospin to that of the observed radii.     

Behavior of pionic hydrogen atoms in liquid organic compounds

Negative pion transfer from pionic hydrogen to other heavier atoms was studied in some liquid organic compounds. The pion capture probability on hydrogen at a particular site in the molecules was obtained using deuterated compounds for alcohols and carboxylic acids. The transfer process to carbon atoms in different chemical states was also studied in the mixtures of C₆ H₁₂ or C₆ H₆+ CCl₄. These methods revealed that the pionic hydrogen atoms originating from hydrogen in different chemical environments showed different behavior. The transfer process was discussed using a large mesomolecular model combined with an external transfer process. This revised version was published online in August 2006 with corrections to the Cover Date.