Numerical Investigation on Accuracy of Defect Detection in HTS Film by Inductive Method

AbstractThe inductive method for measuring the critical current density in a high-temperature superconducting (HTS) film has been reproduced numerically. To this end, a numerical code has been developed for analyzing the time evolution of a shielding current density in the HTS film containing a crack. The results of computations show that the accuracy of the inductive method is degraded due to the crack or the film edge. This result means that the inductive method can be applied to the crack detection. However, the crack located near the film edge cannot be detected because the crack is treated the same as the film edge

AUTOMATIC NUMERICAL ELEMENT GENERATION BY BOUNDARY-FITTED CURVILINEAR COORDINATE SYSTEM

A method for dividing a two-dimensional multi-connected region of a complex shape into a set of triangular elements is developed. A region of a complex shape in the physical plane is divided into some simply connected subregions, and each subregion is mapped onto a square region in the transformed plane. The inverse functions of the mapping are determined by the solution to elliptic partial differential equations with the Dirichlet boundary conditions. After the square region is divided into a set of finite elements, each element is inversely mapped onto the subregions by use of the functions. The finite element data for the global region are made of those for the divided subregions

NUMERICAL ANALYSIS ON MAGNETIC SHIELDING OF AXIALLY SYMMETRIC SUPERCONDUCTING PLATE

The effects of the superconducting plate shape on the magnetic shielding are investigated. The plate shape is assumed to be axially symmetric and the permeability of the plate is assumed non-zero. A numerical code to calculate the magnetostatic field around the plate is developed and the spatial distributions of the decay factors are calculated by means of the code. The results of computations show that the magnetic shielding becomes large with the increase of triangularity and with the decrease of ellipticity

MAGNETOHYDRODYNAMIC EQUILIBRIUM OF HELICITY-INJECTED SPHEROMAK BY COMBINATION OF FDM AND BEM

The sustainment of the spheromak has been successfully achieved by DC helicity injection in the FACT device at Himeji Institute of Technology. The flux conserver actually used in the experiments has the shielding wall to prevent the plasma from being in contact with the divertor bias coil. Equilibrium configurations of the spheromak in the flux conserver with the shielding wall and the divertor bias coil are numerically determined by using the combination of the finite difference and the boundary element method. Several results for equilibrium configurations and their equilibrium quantities are presented. On the basis of the results, the effects of the divertor bias coil on equilibrium configurations of the helicity-injected spheromak are investigated

RNA-Seq reveals virus–virus and virus–plant interactions in nature

As research on plant viruses has focused mainly on crop diseases, little is known about these viruses in natural environments. To understand the ecology of viruses in natural systems, comprehensive information on virus–virus and virus–host interactions is required. We applied RNA-Seq to plants from a natural population of Arabidopsis halleri subsp. gemmifera to simultaneously determine the presence/absence of all sequence-reported viruses, identify novel viruses and quantify the host transcriptome. By introducing the criteria of read number and genome coverage, we detected infections by Turnip mosaic virus (TuMV), Cucumber mosaic virus and Brassica yellows virus. Active TuMV replication was observed by ultramicroscopy. De novo assembly further identified a novel partitivirus, Arabidopsis halleri partitivirus 1. Interestingly, virus reads reached a maximum level that was equivalent to that of the host's total mRNA, although asymptomatic infection was common. AhgAGO2, a key gene in host defence systems, was upregulated in TuMV-infected plants. Multiple infection was frequent in TuMV-infected leaves, suggesting that TuMV facilitates multiple infection, probably by suppressing host RNA silencing. Revealing hidden plant–virus interactions in nature can enhance our understanding of biological interactions and may have agricultural applications

Localization of dynamin 2 in rat seminiferous tubules during the spermatogenic cycle.

Dynamin is a protein essential to endocytosis. Dynamin 2, a dynamin isoform, is expressed most intensely in testicular tissue; however, precise localization has never been studied. Therefore, we investigated the expression of dynamin 2 in rat testicular tissue using immunohistochemical methods, and discuss here the physiological function of this protein. Testicular tissues were obtained from Wistar rats at 10, 21 and 63 days of age. Immunohistochemistrical examination and Western blot analysis were conducted using dynamin 2 specific antibody. Western blot analysis showed that expression in 21- and 63-day-old rats was more intense than that in 10-day-old rats. Dynamin 2 expression was observed using immunohistochemical method in the seminiferous tubules of all rats. In the 63-day-old rats, the expression was intense, especially in spermatids in the earlier maturation stages and in spermatocytes, and was observed in Sertoli cells. However, in spermatids, the expression gradually declined as spermatids matured to spermatozoa. In the 21-day-old rats, the expression was evident in spermatocytes and Sertoli cells, but that in the 10-day-old rats was weak. Intense expression of dynamin 2 during spermatogenesis suggests that this protein plays an important role in this process.</p

Equivalent-Circuit Model for Axisymmetric High-Temperature Superconducting Film: Application to Contactless jC Measurement System and Pellet Injection System

A high-temperature superconducting (HTS) film is used for numerous engineering devices. The analysis of the shielding current density in the HTS is essential to develop the HTS devices. By using the equivalent-circuit model (ECM) [1] , the analysis of the shielding current density becomes equivalent to solving the initial-value problem of the 1st-order ordinary differential system

Current Distribution Optimization by Using Genetic-Algorithm Based On-Off Method: Application to Pellet Injection System

The current distribution in the electromagnet is optimized by using the genetic-algorithm based on-off method so as to maximize the acceleration performance of the Superconducting Linear Acceleration (SLA) system. In the SLA system, a pellet container is accelerated by the interaction between a shielding current density and an applied magnetic field. By using the equivalent-circuit model, the distribution of the shielding current density is approximated as a set of the multiple current loops. In contrast, the current distribution in the electromagnet is represented by means of the on-off method. As the method for optimizing the current distribution in the electromagnet, two types of genetic algorithms are adopted. The results of computations show that the pellet velocity for the optimized current distribution is 1.3 times as fast as that for the homogeneous current distribution

機械学習を用いた農作物の等級判別 －農業におけるPBL の実施に向けた検討－

本稿では、農業における産業PBLの実施に向けて機械学習を用いて農作物の等級を判定する「AI等級判別システムの構築」を試み、試行実験を実施した。試行実験の結果、農業におけるAIを含むIT技術の導入は、学生らのPBLに適していることが確認できた。今回の試行実験の結果をもとに、学生らのPBL教材が構築できると考えられる

RNA-Seq reveals virus–virus and virus–plant interactions in nature

As research on plant viruses has focused mainly on crop diseases, little is known about these viruses in natural environments. To understand the ecology of viruses in natural systems, comprehensive information on virus–virus and virus–host interactions is required. We applied RNA-Seq to plants from a natural population of Arabidopsis halleri subsp. gemmifera to simultaneously determine the presence/absence of all sequence-reported viruses, identify novel viruses and quantify the host transcriptome. By introducing the criteria of read number and genome coverage, we detected infections by Turnip mosaic virus (TuMV), Cucumber mosaic virus and Brassica yellows virus. Active TuMV replication was observed by ultramicroscopy. De novo assembly further identified a novel partitivirus, Arabidopsis halleri partitivirus 1. Interestingly, virus reads reached a maximum level that was equivalent to that of the host's total mRNA, although asymptomatic infection was common. AhgAGO2, a key gene in host defence systems, was upregulated in TuMV-infected plants. Multiple infection was frequent in TuMV-infected leaves, suggesting that TuMV facilitates multiple infection, probably by suppressing host RNA silencing. Revealing hidden plant–virus interactions in nature can enhance our understanding of biological interactions and may have agricultural applications