Monte Carlo Calculation of Neutrons Transmitted through Matter

The neutron Monte Carlo code, CYGNUS, which is written in Fortran IV has been shown. This code can easily be used for several limitted geometries and requires considerably less computing time than O5R. In this paper, two methods of calculation are described : one by weight method and the other by collision density method, and the two techniques for determination of the anisotropic scattering angle in the center-of-mass system, i.e., Legendre expansion and Coveyou technique, and the method for determination of the excited level in the inelastic scattering are also described. The results calculated with CYGNUS code are compared with the numerical solution by PALLAS code for the sealer flux in water and graphite spheres, and with experimental spectra for the angular neutron flux in water and iron shields. The agreement obtained between the CYGNUS calculations and numerical or experimental results is good

Study on a New Train Control System in the IoT Era: From the Viewpoint of Safety2.0

Safety2.0 which advocates cooperative safety is attracting attention. Assuming that Industry4.0 proposed by the German authorities is an IoT-based production revolution, Safety2.0 is a Japanese-originated proposal that seeks to create a more flexible and sophisticated safety by introducing Internet of Things (IoT) into production sites. This chapter introduces the concepts of Safety2.0 and its spread internationally, focusing on the activities of IGSAP, a Safety2.0 promoter. Furthermore, we look back on the conventional train control from the viewpoint of Safetyx.x and look at the appearance of the train control suitable for Safety2.0 using IoT. As a result, in this chapter, we propose a simple and smart train control system unified train control system (UTCS), in which a train control system is realized in a hierarchical structure of a logic layer, a network layer, and a terminal layer, and discuss its processing method

Single-photon interference over 150-km transmission using silica-based integrated-optic interferometers for quantum cryptography

We have demonstrated single-photon interference over 150 km using time-division interferometers for quantum cryptography, which were composed of two integrated-optic asymmetric Mach-Zehnder interferometers, and balanced gated-mode photon detectors. The observed fringe visibility was more than 80% after 150-km transmission.Comment: 10 pages, 2 figures, submitted to Electronics Letter

Effect of some naturally occurring iron ion chelators on the formation of radicals in the reaction mixtures of rat liver microsomes with ADP, Fe3+ and NADPH

In order to clarify the mechanism by polyphenols of protective effects against oxidative damage or by quinolinic acid of its neurotoxic and inflammatory actions, effects of polyphenols or quinolinic acid on the radical formation were examined. The ESR measurements showed that some polyphenols such as caffeic acid, catechol, gallic acid, D-(+)-catechin, L-dopa, chlorogenic acid and L-noradrenaline inhibited the formation of radicals in the reaction mixture of rat liver microsomes with ADP, Fe3+ and NADPH. The ESR measurements showed that α-picolinic acid, 2,6-pyridinedicarboxylic acid and quinolinic acid (2,3-pyridinedicarboxylic acid) enhanced the formation of radicals in the reaction mixture of rat liver microsomes with Fe3+ and NADPH. Caffeic acid and α-picolinic acid had no effects on the formation of radicals in the presence of EDTA, suggesting that the chelation of iron ion seems to be related to the inhibitory and enhanced effects. The polyphenols may exert protective effects against oxidative damage of erythrocyte membrane, ethanol-induced fatty livers, cardiovascular diseases, inflammatory and cancer through the mechanism. On the other hand, quinolinic acid may exert its neurotoxic and inflammatory effects because of the enhanced effect on the radical formation

Spacial Distribution of Photoneutrons in an Iron Slab Produced by 20-MeV Electron Bombardment

Photoneutron distribution was measured with activation of aluminum and magnesium in an iron slab bombarded by a beam of 20-MeV electrons from a linear accelerator. In order to compare with the experimental results, the spacial neutron distribution was calculated as follows : the photoneutron source distribution originating from the photonuclear reaction was calculated by an approximate analytical method ; and the neutron distribution in the medium was calculated on the basis of this distributed source by Monte Carlo code, CYGNUS. The calculated neutron distribution was in good agreement with the measured distribution, using activities of aluminum detectors. From the comparison of both saturated activities of aluminum and magnesium, it is found that the photonuclear effects are remarkable when γ is equal to 10 cm and Z is between 2 and 5 cm. The spacial distribution of neutron flux above about 6.5 MeV in the iron slab is nearly spherical symmetric around the beam incident point ; and an exponential attenuation with the slope of effective removal cross section of iron, ∑ₑffᴿ＝0.172 cm⁻¹