University of Electro-Communications

About: University of Electro-Communications is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Laser & Robot. The organization has 8041 authors who have published 16950 publications receiving 235832 citations. The organization is also known as: UEC & Denki-Tsūshin Daigaku.

Optical frequency-domain reflectometry with a rapid wavelength-scanning superstructure-grating distributed Bragg reflector laser

Abstract: Superstructure-grating distributed Bragg reflector lasers are particularly suited for optical frequency-domain reflectometry optical-coherence tomography with wide wavelength tunability and frequency agility. We report theoretical estimates of and experimental results for the data acquisition speed, the observable depth range, the resolution, and the dynamic range of an optical frequency-domain reflectometry system that uses a superstructure-grating distributed Bragg reflector laser whose wavelength can be tuned from 1533 to 1574 nm with a tuning speed of 10 μs/0.1-nm step.

Operando 3D Visualization of Migration and Degradation of a Platinum Cathode Catalyst in a Polymer Electrolyte Fuel Cell.

Abstract: The three-dimensional (3D) distribution and oxidation state of a Pt cathode catalyst in a practical membrane electrode assembly (MEA) were visualized in a practical polymer electrolyte fuel cell (PEFC) under fuel-cell operating conditions. Operando 3D computed-tomography imaging with X-ray absorption near edge structure (XANES) spectroscopy (CT-XANES) clearly revealed the heterogeneous migration and degradation of Pt cathode catalyst in an MEA during accelerated degradation test (ADT) of PEFC. The degradative Pt migration proceeded over the entire cathode catalyst layer and spread to MEA depth direction into the Nafion membrane.

Pair Plasma Dominance in the 3C 279 Jet on Parsec Scales

Abstract: We have investigated whether a pc-scale jet of 3C 279 is dominated by a normal plasma or an electronpositron plasma. By analyzing Very Long Baseline Interferometry data between 1983 and 1990, and utilizing the theory of synchrotron self-absorption, we have derived the lower limits for the proper electron number density. Comparing the lower limit with another independent constraint for the electron density that is deduced from the kinetic luminosity, we find that the core and components C3 and C4 are likely dominated by an electron-positron plasma.