Nucleon mean free path in nuclear matter based on nuclear Schwinger-Dyson formalism

A mean free path of nucleon moving through nuclear matter with kinetic energy of more than 100MeV is formulated based on the bare vertex nuclear Schwinger-Dyson (BNSD) method in the Walecka model. The self-energy which is derived from the higher order diagrams more than the forth order includes the Feynman part of propagator of energetic nucleon and grows up rapidly as an increase of kinetic energy. To avoid too large growth of these diagrams, meson propagators are modified by introducing some form factors to take account of a internal structure of hadron. It is confirmed that the mean free path calculated by the BNSD method agrees good with experimental data if a reasonable form factor is chosen, i.e., a dipole (quadrupole) type of form factor with a cut-off parameter about 750 MeV $\sim$ 1000 MeV (1200 MeV $\sim$ 1500 MeV)

Partially-disordered photonic-crystal thin films for enhanced and robust photovoltaics

We present a general framework for the design of thin-film photovoltaics based on a partially-disordered photonic crystal that has both enhanced absorption for light trapping and reduced sensitivity to the angle and polarization of incident radiation. The absorption characteristics of different lattice structures are investigated as an initial periodic structure is gradually perturbed. We find that an optimal amount of disorder controllably introduced into a multi-lattice photonic crystal causes the characteristic narrow-band, resonant peaks to be broadened resulting in a device with enhanced and robust performance ideal for typical operating conditions of photovoltaic applications.Comment: 5 pages, 4 figure

Vacuum Effects and Compressional Properties of Nuclear Matter in Cutoff Field Theory

Including the vacuum effects, the compressional properties of nuclear matter are studied in the cutoff field theory. Under the Hartree approximation, the low-energy effective Lagrangian is derived in the framework of the renormalization group methods. The coefficients are determined in a way where the physical results hardly depend on the value of the cutoff which is conveniently introduced into the theory. It is shown that, to reproduce the empirical data of the nucleus incompressibility, the compressibility of the nuclear matter is favorable to be 250$\sim$350MeV.Comment: PACS numbers, 21.65.+

Effects of specific cultivar usage and preparation methods in Japanese potato starches.

Potato starch is one of the important agricultural products in Hokkaido, the northernmost and second largest island of Japan. The aim of this study was to evaluate the effects of cultivars and starch preparation methods on the quality parameters of Japanese potato starch. Potato starches from four cultivars, Hokkaikogane, Eniwa, Benimaru and Norin No. 1, grown over a period of several years in Hokkaido were used. The starches produced with tap water in a local starch factory and with distilled water in a laboratory were investigated for phosphorus content, median granule size and peak viscosity and breakdown as determined with a Rapid Visco Analyzer (RVA). Among the starch samples used in this study, significant differences were observed across starch quality parameters. We investigated the differences in quality parameters as an effect of individual cultivars. The starch median granule size among potato cultivars varied in the following order: Benimaru (43.1 μm) > Hokkaikogane (39.1 μm) ≈Eniwa (38.2 μm) > Norin No. 1 (33.9 μm). We found that starches of Hokkaikogane and Eniwa, both with a measurably higher phosphorus content, displayed significantly higher peak viscosity and breakdown than those of Benimaru and Norin No. 1. We also examined the effect that the preparation method has on starch quality parameters within the same potato cultivar. We found that the starch preparation method had a little or no influence on phosphorus content. Median granule size was also completely independent on the preparation method. The RVA evaluation revealed that, even within the same cultivar, starches produced in a factory showed lower peak viscosity and breakdown than those produced in a laboratory

Measurement of AGN dust extinction based on the near-infrared flux variability of WISE data

We present the measurement of the line-of-sight extinction of the dusty torus for a large number of obscured active galactic nuclei (AGNs) based on the reddening of the colour of the variable flux component in near-infrared (NIR) wavelengths. We collected long-term monitoring data by $\textit{Wide-field Infrared Survey Explorer (WISE)}$ for 513 local AGNs catalogued by the $\mathit{Swift/}$BAT AGN Spectroscopic Survey (BASS) and found that the multi-epoch NIR flux data in two different bands (WISE $W1$ and $W2$) are tightly correlated for more than 90% of the targets. The flux variation gradient (FVG) in the $W1$ and $W2$ bands was derived by applying linear regression analysis, and we reported that those for unobscured AGNs fall in a relatively narrow range, whereas those for obscured AGNs are distributed in a redder and broader range. The AGN's line-of-sight dust extinction ($A_V$) is calculated using the amount of the reddening in the FVG and is compared with the neutral hydrogen column density ($N_{\rm{}H}$) of the BASS catalogue. We found that the $N_{\rm{}H}/A_V$ ratios of obscured AGNs are greater than those of the Galactic diffuse interstellar medium (ISM) and are distributed with a large scatter by at most two orders of magnitude. Furthermore, we found that the lower envelope of the $N_{\rm{}H}/A_V$ of obscured AGNs is comparable to the Galactic diffuse ISM. These properties of the $N_{\rm{}H}/A_V$ can be explained by increase in the $N_{\rm{}H}$ attributed to the dust-free gas clouds covering the line of sight in the broad-line region.Comment: 11 pages, 7 figures, published in MNRA

Effective meson masses, effective meson-nucleon couplings and neutron star radii

Using the generalized mean field theory, we have studied the relation among the effective meson masses, the effective meson-nucleon couplings and the equation of state (EOS) in asymmetric nuclear matter. If the effective omega-meson mass becomes smaller at high density, the EOS becomes stiffer. However, if we require that the omega-meson mean field is proportional to the baryon density, the effective omega-nucleon coupling automatically becomes smaller at the same time as the effective omega-meson mass becomes smaller. Consequently, the EOS becomes softer. A similar relation is found for the effective rho-meson mass and the effective rho-nucleon coupling. We have also studied the relation among the effective meson masses, the effective meson-nucleon couplings and a radius R of a neutron star. The R depends somewhat on the value of the effective omega-meson mass and the effective omega-nucleon coupling.Comment: 29pages, 24 figure

Quark condensate in nuclear matter based on Nuclear Schwinger-Dyson formalism

The effects of higher order corrections of ring diagrams for the quark condensate are studied by using the bare vertex Nuclear Schwinger Dyson formalism based on $\sigma$-$\omega$ model. At the high density the quark condensate is reduced by the higher order contribution of ring diagrams more than the mean field theory or the Hartree-Fock

Factors affecting the digestibility of raw and gelatinized potato starches.

The enzymatic digestibilities of raw and gelatinized starches in various potato starches, as well as sweet potato, cassava, and yam starches, were estimated, along with other starch properties, such as the phosphorus content, median granule size, and rapid visco analyzer (RVA) pasting properties. Furthermore, correlation coefficients were calculated between the hydrolysis rates (HR) by amylase and other starch quality parameters. A larger granule size was closely associated with a lower HR in raw starch, while the HR in gelatinized starch did not correlate with the median granule size. An increase in phosphorus content resulted in a definitely lower HR in raw starch and tended to decrease the HR in gelatinized starch for the composite of potato and other starches. In contrast, no correlation coefficients of the phosphorus content with the HRs in raw and gelatinized starches were observed within potato starches. Starches with higher peak viscosity and breakdown showed a lower HR in raw starch, while few or no effects of these RVA parameters on the HR in gelatinized starch were observed for the composite of potato and other starches or among potato starches, respectively