Branching ratio for preionization and predissociation of a superexcited state of a diatomic molecule

The branching ratio for preionization and predissociation is studied qualitatively on the basis of a previously proposed simplisitc classical probabilistic model of the superexcited states of molecules. The isotope effect is also discussed.     

Ultrasonic relaxation and volumetric studies of micelle-monomer exchange process in aqueous solutions of sodium and cesium perfluorooctanoates

Ultrasonic absorption measurements of aqueous solutions of sodium perfluorooctanoate (SPFO) and of cesium perfluorooctanoate (CsPFO) were carried out in the frequency range 0.2–90 MHz at 25°C. A single ultrasonic relaxation process is observed in all solutions investigated. The observed relaxation process should be ascribed to a “fast” relaxation process due to an exchange of surfactant monomer between micelle and bulk solution. The mean dissociation rate constant and the magnitude of the volume difference due to the exchange process are determined by applying the relations derived by Aniansson and Wall and by Teubner, respectively. The ratio of the aggregation number of the micelle to the mean dissociation rate constant is reduced to about one-half and the volume difference decreases when the counterion of the perfluorooctanoate changes from Na⁺ to Cs⁺. Precise density measurements were also carried out to support information obtained from the ultrasonic relaxation study. Magnitudes of the volume difference estimated from the two independent studies above are in approximate agreement with each other. However, the volume difference determined from the density measurements is slightly larger than that determined by ultrasonic study and almost independent of the species of the counterion.     

Appreciation of a collisional-radiative model for the description of an inductively coupled argon plasma

The collisional-radiative model has been applied to the argon ICP discharge in order to elucidate the excitation mechanism in the plasma. The population density distributions of 25 argon energy levels were calculated under a steady-state approximation by using the literature values of electron number density, 5 × 10 ¹⁴cm^?3 and electron temperature, 9000 K. In the case of an optically thin plasma, in which the induced absorption can be neglected, the calculated population densities showed an overpopulation for low lying states, and were very close to LTE values for the upper levels. These results suggest the following excitation mechanisms in the argon ICP; corona model for lower levels and ladder-like excitation and ionization by electron impact for upper levels. According to the present calculation, the non-overpopulation of argon metastable can be interpreted by the interconversion between metastable and radiative states. It has been found that the induced absorption of resonance lines in an optically thick plasma and the motion of species in an inhomogeneous plasma have significant effects on the population densities. The non-linear processes by collision between heavy particles were not predominant compared to electron impact processes.     

Orthogonal wavelet analysis of turbulent wakes behind various bluff bodies

The multi-scale structures of turbulent wakes generated by three kinds of bluff body, i.e. circular cylinder, square cylinder and compound of cylinder and square (CS) cylinders, have been experimentally investigated in this paper. Firstly, the instantaneous velocity fields and vorticity were measured by the high-speed PIV technique in a circulating water channel. The instantaneous streamlines and corresponding normalized vorticity contours are obtained at a Reynolds number of 5600. Then one- and two-dimensional wavelet multi-resolution technique was used to analyze the instantaneous velocities and vorticity measured by the high-speed PIV. The turbulence structures were separated into a number of subsets based on their central frequencies, which are linked with the turbulence scales. The instantaneous vorticity and Reynolds shear stresses of various scales were examined and compared between the three generators. It is found that the large-scale turbulent structure makes the largest contribution to the vorticity and Reynolds shear stresses for the three wake generators and exhibits a strong dependence upon the initial conditions or the wake generators. The large-scale vorticity and the sizes of vortex in the circular and square cylinders are larger than those in the CS cylinder wake. The contributions to the Reynolds shear stresses from the large-scale turbulent structures account for 90-96% to the measured maximum Reynolds shear stresses for the three wakes. However, the small-scale structures make less contribution to the vorticity and Reynolds shear stresses.     

Parallel computing of radiative transfer in relativistic jets using Monte Carlo method

We present numerical attempts of radiative transfer in a relativistic scattering flow that can produce gamma rays using a three-dimensional Monte Carlo code. We prepared an initial background flowfield obtained from hydrodynamical simulation of a relativistic jet in which Thomson scattering dominates compared to absorption, and solved the radiative transfer equation for the background evolved by a simple expansion model. Since a large number of sample particles is required for an accurate computation, we have parallelized the Monte Carlo code in order to obtain solutions in a practical computational time even for a long-term simulation coupled with a time-dependent flowfield. Using this code, higher parallel efficiency is achieved with larger number of particles. The obtained light curve from the simple model shows a signal of the transition from the opaque post-shock flow to the transparent regime as the flow expands, and the high-energy photons are generated by not only the Doppler boosting but also the inverse Compton scattering.     

Improved omnibus test statistic for normality

We propose a new omnibus test statistic for normality based on the Jarque–Bera test statistic. We give the exact first four moments of the null distribution for the statistic using a computer algebra system. Our proposed statistic is an improvement of Jarque–Bera test statistic. Then the cumulants of the standardized statistic satisfy the Cornish–Fisher assumption. We give a normalizing transformation of the statistic based on the Wilson–Hilferty transformation.     

AF Embeddability of Crossed Products of AT Algebras by the Integers and Its Application

We will show that the crossed products of unital simple real rank zero AT algebras by the integers are AF embeddable. This is a generalization of Brown's AF embedding theorem. As an application, we will prove the AF embeddability of crossed product algebras arising from certain minimal dynamical systems induced by two commuting homeomorphisms.     

AIC for the non-concave penalized likelihood method

Annals of the Institute of Statistical Mathematics - Non-concave penalized maximum likelihood methods are widely used because they are more efficient than the Lasso. They include a tuning parameter...     

Prethick Subcategories of Modules and Characterizations of Local Rings

This article studies characterizing local rings in terms of homological dimensions. The key tool is the notion of a prethick subcategory which we introduce in this article. Our methods recover the theorems of Salarian, Sather-Wagstaff, and Yassemi.