Saari's homographic conjecture for planar equal-mass three-body problem in Newton gravity

Saari's homographic conjecture in N-body problem under the Newton gravity is the following; configurational measure \mu=\sqrt{I}U, which is the product of square root of the moment of inertia I=(\sum m_k)^{-1}\sum m_i m_j r_{ij}^2 and the potential function U=\sum m_i m_j/r_{ij}, is constant if and only if the motion is homographic. Where m_k represents mass of body k and r_{ij} represents distance between bodies i and j. We prove this conjecture for planar equal-mass three-body problem. In this work, we use three sets of shape variables. In the first step, we use \zeta=3q_3/(2(q_2-q_1)) where q_k \in \mathbb{C} represents position of body k. Using r_1=r_{23}/r_{12} and r_2=r_{31}/r_{12} in intermediate step, we finally use \mu itself and \rho=I^{3/2}/(r_{12}r_{23}r_{31}). The shape variables \mu and \rho make our proof simple

Theoretical Analysis of a Ridged-Waveguide Mounting Structure

The driving-point impedance of a single-gap thin conductor strip, a model of the ribbon-and-pedestal of diode package, mounted across the gap of a ridged waveguide has been derived using the induced EMF method. The dyadic Green\u27s function for the ridged waveguide is derived to facilitate the analysis. An equivalent circuit is developed which involves an infinite array of transformers representing the couplings between the conductor strip and the waveguide normal modes. Numerical results for a typical example are presented to discuss the validity of the analytical results and also to demonstrate a remarkably smooth behavior of the driving-point impedance of the mount over a frequency range from 5.4 to 25.4 GHz

イシドンコはチョウモドキの新宿主

島根県高津川水系匹見川の支流，石谷川で採集したイシドンコOdontobutis hikimiusの体表からチョウモドキArgulus coregoni Thorell, 1864の雌成体を得た。イシドンコはチョウモドキの新宿主である。また，チョウモドキはイシドンコから見出された最初の寄生虫である。An adult female of the argulid branchiuran Argulus coregoni Thorell, 1864 was collected from the body surface of a recently described, rare odontobutid Odontobutis hikimius (called “ishidonko”) in the Ishitani River, a tributary of the Hikimi River within the Takatsu River system, Shimane Prefecture, Japan. This collection represents a new host record for A. coregoni. This branchiuran is the first species of parasite found from O. hikimius

Investigation of Electromagnetic Noise Transmission Characteristics from AC Mains Port to Telecommunication Port

A method of evaluating the isolation factor from an AC mains port to a telecommunication port was investigated. Telecommunication equipment was represented by a 4-port network consisting of a pair of wire and ground. The relationship between input and output signals of the network was represented by an F-matrix and the isolation factor (ratio of input to output signals) was derived from the matrix. We developed a method of measuring the parameters and the measured values for a resistance-network agree well with calculated ones. The evaluation results of the isolation factor for three types of telecommunication equipment show that isolation for differential-mode noise from AC mains to telecommunication ports is larger than that for common-mode noise.2003 IEEE Symposium on Electromagnetic Compatibility, August 18-22, 2003, Bosto

Anion ordering enables fast H¯ conduction at low temperatures

H¯イオンの低温高速伝導を実現. 京都大学プレスリリース. 2021-06-03.Bringing order to hydrogen energy devices. 京都大学プレスリリース. 2021-06-03.The introduction of chemical disorder by substitutional chemistry into ionic conductors is the most commonly used strategy to stabilize high-symmetric phases while maintaining ionic conductivity at lower temperatures. In recent years, hydride materials have received much attention owing to their potential for new energy applications, but there remains room for development in ionic conductivity below 300°C. Here, we show that layered anion-ordered Ba2−δH3−2δX (X = Cl, Br, and I) exhibit a remarkable conductivity, reaching 1 mS cm⁻¹ at 200°C, with low activation barriers allowing H⁻ conduction even at room temperature. In contrast to structurally related BaH2 (i.e., Ba2H4), the layered anion order in Ba2−δH3−2δX, along with Schottky defects, likely suppresses a structural transition, rather than the traditional chemical disorder, while retaining a highly symmetric hexagonal lattice. This discovery could open a new direction in electrochemical use of hydrogen in synthetic processes and energy devices

Evaluation of Longitudinal Conversion Loss (LCL) for Indoor AC Mains Line

Influence to electromagnetic environment has been studied for power line communication (PLC). Longitudinal conversion loss (LCL) and input impedance are important parameters to evaluate the influence. Indoor AC mains line is modeled considering with typical conditions of Japanese house. The modeled line and electric equipment are presented with 4-port F-matrixes. The parameters of 4-port F-matrix are determined from calculation and measurement. Using this model, the input impedance and the LCL are calculated. The analysis model is examined by a simple network, and the results show that the calculation values almost agree with the measured values. The input impedance and the LCL are investigated for actual AC mains line, and the measured results almost agree with the calculated value.2003 IEEE Symposium on Electromagnetic Compatibility, August 18-22, 2003, Boston, MA, US

Soft X-ray Absorption and Photoemission Studies of Ferromagnetic Mn-Implanted 3CC-SiC

We have performed x-ray photoemission spectroscopy (XPS), x-ray absorption spectroscopy (XAS), and resonant photoemission spectroscopy (RPES) measurements of Mn-implanted 3$C$-SiC (3$C$-SiC:Mn) and carbon-incorporated Mn$_{5}$Si$_{2}$ (Mn$_{5}$Si$_{2}$:C). The Mn 2$p$ core-level XPS and XAS spectra of 3$C$-SiC:Mn and Mn$_{5}$Si$_{2}$:C were similar to each other and showed "intermediate" behaviors between the localized and itinerant Mn 3$d$ states. The intensity at the Fermi level was found to be suppressed in 3$C$-SiC:Mn compared with Mn$_{5}$Si$_{2}$:C. These observations are consistent with the formation of Mn$_{5}$Si$_{2}$:C clusters in the 3$C$-SiC host, as observed in a recent transmission electron microscopy study.Comment: 4 pages, 3 figure

A Study of PLC Signal Influence on VDSL System by Induction between Indoor Power Line and Telecommunication Line

Due to the progress of information technology in recent years, power line communication (PLC) can be considered as a solution for configuring an indoor communication system. However, the influence on other systems caused by PLC signal induction has not yet been investigated. This paper presents a study on that influence. The induction voltage to a telecommunication line was analyzed by using an 8-port network. The calculation results nearly agree with the measurements. The investigation using a very high bit rate digital subscriber line (VDSL) modem indicates that the VDSL communication may not be degraded under normal conditions for the system using the experiment.2004 International Symposium on Electromagnetic Compatibility (EMC\u2704/Sendai), June 1-4, 2004, Sendai International Center, Sendai, Japa