Muon Nuclear Data

We plan to develop a new nuclear database for muon-induced nuclear reactions (muon nuclear data). The database will consist of (1) energies and intensities of the muonic X rays, (2) lifetimes of the muonic atom, (3) production branching ratio of the residual nuclei by muon capture, (4) emission probabilities of the particles after muon capture, and (5) energy spectra of the emitted particles after muon capture. In this paper, we review the present status and current investigations for the muon nuclear data.Comment: Proceedings for Joint Symposium on Nuclear Data and PHITS in 2023, in print (JAEA-Conf series

A Terrestrial SER Estimation Methodology based on Simulation coupled with One-Time Neutron Irradiation Testing

電子機器の信頼性評価の迅速化に光明 --様々な中性子施設で半導体ソフトエラー評価を可能にする技術を開発--. 京都大学プレスリリース. 2023-06-08.Terrestrial soft error rates (SERs) are generally estimated by performing an experiment using spallation neutron beam with the energy spectrum being similar to that of the terrestrial neutrons or at least four measurements using various (quasi-)mono-energetic neutron and/or proton sources to determine the parameters of the Weibull function. We here propose a method to estimate the terrestrial SERs based on simulation coupled with one-time neutron irradiation testing which can be applied to various kinds of neutron sources. In this method, the dependences of single event upset (SEU) cross sections on the neutron energy and the critical charge are calculated by simulation using Particle and Heavy Ion Transport code System (PHITS). The critical charge is used as the only calibration parameter, which is adjusted to reproduce the SER measured by one-time neutron irradiation. The validity of our method is investigated for 65-nm bulk SRAMs with the measured data using various neutron sources in Japan. Our method generally provides the reasonable terrestrial SERs compared with those obtained by the Weibull function method. This result indicates the feasibility of evaluating the terrestrial SER using one of the various neutron sources available all over the world, including those not dedicated to SER measurement. We also investigate the necessity of the elaborated geometry of device under test (DUT) for the accuracy of the simulation. It is shown that detailed material compositions of DUT are not necessary in our method except when the one-time irradiation is performed using the neutron source that contains a high-quantity of low-energy neutrons below 8 MeV. Furthermore, we confirm that the configuration of the sensitive volume can be simplified without sacrificing the estimation accuracy. These simplifications in the simulation help to reduce the modeling and calculation cost in SER estimation

Long-Term Effects of Labor Market Conditions on Family Formation for Japanese Youth

This study aims to examine how each cohort's family formation is affected by labor market conditions experienced in youth in Japan. Although deterioration in youth employment opportunities has often been blamed for Japan's declining marriage and fertility rates, the effects of slack labor market conditions on marriage and fertility are theoretically unclear. We estimate the effects of regional labor market conditions on marriage and fertility, controlling for nation-wide year effects and prefecture fixed effects, and find the following. First, the male unemployment rate is negatively correlated with marriage of women in the local labor market, although the correlation is weak and concentrated on the less educated group. Second, high school-educated women who experienced a recession while entering the labor market are less likely to have children and tend to marry later. In contrast, a recession at entry to the labor market rather increases fertility among college-educated women. The overall impact of labor market conditions experienced in youth on family formation is relatively weak, compared to the substantial losses in earnings and employment stability documented by the existing studies

Analysis software for upper atmospheric data developed by the IUGONET project and its application to polar science

To comprehensively understand the Arctic and Antarctic upper atmosphere, it is often crucial to analyze various data that are obtained from many regions. Infrastructure that promotes such interdisciplinary studies on the upper atmosphere has been developed by a Japanese inter-university project called the Inter-university Upper atmosphere Global Observation Network (IUGONET). The objective of this paper is to describe the infrastructure and tools developed by IUGONET. We focus on the data analysis software. It is written in Interactive Data Language (IDL) and is a plug-in for the THEMIS Data Analysis Software suite (TDAS), which is a set of IDL libraries used to visualize and analyze satellite- and ground-based data. We present plots of upper atmospheric data provided by IUGONET as examples of applications, and verify the usefulness of the software in the study of polar science. We discuss IUGONET’s new and unique developments, i.e., an executable file of TDAS that can run on the IDL Virtual Machine, IDL routines to retrieve metadata from the IUGONET database, and an archive of 3-D simulation data that uses the Common Data Format so that it can easily be used with TDAS

How is the IUGONET project using TDAS?

GEM Mini-Workshop, San Francisco; 2011-12-0

Quaternary Complexes Modified from pDNA and Poly-l-Lysine Complexes to Enhance pH-Buffering Effect and Suppress Cytotoxicity

We developed a modified complex of pDNA and poly-l-lysine (PLL) by the addition of poly-l-histidine (PLH) and γ-polyglutamic acid (γ-PGA) to enhance its pH-buffering effect and suppress cytotoxicity. The binary and ternary complexes of pDNA with PLL or/and PLH showed particle sizes of approximately 52-76 nm with cationic surface charge. The ternary complexes showed much higher gene expression than the binary complexes with PLL. The mixed solution of PLL and PLH showed higher buffering capacity than PLL solution. The high gene expression of ternary complexes was reduced by bafilomycin A1. These results indicated the addition of PLH to PLL complexes promoted endosomal escape by enhancing the pH-buffering effect. The binary and ternary complexes showed cytotoxicity and blood agglutination because of their cationic surface charge. We therefore developed quaternary complexes by the addition of anionic γ-PGA, which was reported to decrease the toxicity of cationic complexes. In fact, quaternary complexes showed no cytotoxicity and blood agglutination. Also, quaternary complexes showed higher gene expression than ternary complexes regardless of their anionic surface charge. Quaternary complexes showed selectively high gene expression in the spleen after their intravenous administration. Thus, we successfully developed the quaternary complexes with high gene expression and no toxicity

Development of metadata database and analysis software for upper atmospheric researches by the IUGONET project

第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月15日（火） 国立極地研究所 2階大会議室前フロ