512 research outputs found

    Ethical Challenges of the COVID-19 Pandemic: A Japanese Perspective

    Get PDF
    This article focuses on how Japan experienced the COVID-19 pandemic. It delineates the various challenges the country faced and the measures the national government took to stop the spread of the infection. The article begins with the author’s personal experience of COVID-19. The second section explains how the Japanese government lacked the legal sanctions to enforce a state of emergency. The third section deals with the current pandemic response as characterized by the increased use of digital technologies to control the spread of the virus. I argue that the lack of effective governance hampered Japan’s timely use of digital technologies. The fourth section will touch on the issues created by the rapid spread of the infection and an increase in the hospitalization rate, focusing on intensive care unit triage and the ethical debates that ensued in Japan. The fifth section discusses the pandemic from the perspective of disaster preparedness and management, exploring the ways the pandemic responses share ethical challenges with responses to other disasters such as earthquakes and typhoons

    Observation of Current-induced Nonlinear Spin Polarization in Pt-Py Bilayers

    Full text link
    We experimentally observe nonlinear spin polarization in metallic bilayers of platinum and permalloy by means of spin-torque ferromagnetic resonance (ST-FMR) with the spin-Hall effects. The ST-FMR results under massive dc current injection contain striking features, which are not caused by extrinsic Joule heating, but by intrinsic nonlinear spin polarization. The emergence of nonlinear spin polarization is consistent with observation of unidirectional spin-Hall magnetoresistance due to magnon generation/annihilation. Moreover, the magnon generation (annihilation) leads to effective magnetization shrinkage (expansion) revealed by the ST-FMR measurements. The present study paves a way to spin-Hall effect based nonlinear spintronic devices as well as 6th-generation mobile communication light sources

    Separation and recovery of carbon dioxide by a membrane flash process utilizing waste thermal energy

    Get PDF
    AbstractThe membrane flash process utilizing waste thermal energy was developed to realize an energy-saving technology and to substitute it for a conventional regenerator. The operating conditions of a membrane flash at high temperature were studied. The DEA concentration and the flashing pressure had optimum values to improve the performance and reduce the energy consumption for CO2 recovery. The petroleum refinery process and iron manufacturing process were proposed for candidate processes that actually had waste energy sources. Energy consumption and costs for CO2 recovery in the membrane flash and chemical absorption were estimated by custom-made program and discussed under the same conditions. The membrane flash was suitable for the CO2 emission sources that had high CO2 concentration independently of the plant scale. The chemical absorption was suitable for large-scale sources, even if the CO2 concentration was low

    Microwave Spectroscopy of a Single Permalloy Chiral Metamolecule on a Coplanar Waveguide

    Get PDF
    We investigate the microwave spectroscopies of a micrometer-sized single permalloy (Py) chiral structure on coplanar waveguides (CPWs). Under an external dc magnetic field applied in a direction perpendicular to the microwave propagation, the Py chiral structure loaded on the center of the CPW signal line shows Kittel-mode ferromagnetic resonance. Contrastingly, the structure on the signal-line edge highlights two additional resonances: spin-wave resonance at a higher frequency, and unique resonance at a lower frequency of approximately 7.8 GHz. The resonance signal at 7.8 GHz originates from magnetically induced, geometry-driven resonance, although the resonance frequency does not depend on the external magnetic field. Moreover, the displacement of the Py structures on the signal line results in nonreciprocal microwave transmission, which is traced back to the edge-guide mode

    Imbalance of CPU temperatures in a blade system and its impact for power consumption of fans

    Get PDF
    We are now developing a new metric of data center power efficiency to fairly evaluate the contribution of each improvement for power efficiency. In order to develop it, we built a testbed of a data center and measured power consumption of each components and environmental variables in some detail, including the power consumption and temperature of each node, rack and air conditioning unit, as well as load on the CPU, Disk I/O and the network. In these measurements we found that there was a significant imbalance of CPU temperatures that caused an imbalance in the power consumption of fans. We clarified the relationship between CPU load and fan speed, and showed that scheduling or rearrangement of nodes could reduce the power consumption of fans. We reduced fan power consumption by a maximum of 62% and total power consumption by a maximum of 12% by changing the scheduling of five nodes, changing the nodes used from hot nodes to cool nodes

    Predicting dust extinction properties of star-forming galaxies from H-alpha/UV ratio

    Full text link
    Using star-forming galaxies sample in the nearby Universe (0.02<z<0.10) selected from the SDSS (DR7) and GALEX all-sky survey (GR5), we present a new empirical calibration for predicting dust extinction of galaxies from H-alpha-to-FUV flux ratio. We find that the H-alpha dust extinction (A(Ha)) derived with H-alpha/H-beta ratio (Balmer decrement) increases with increasing H-alpha/UV ratio as expected, but there remains a considerable scatter around the relation, which is largely dependent on stellar mass and/or H-alpha equivalent width (EW(Ha)). At fixed H-alpha/UV ratio, galaxies with higher stellar mass (or galaxies with lower EW(Ha)) tend to be more highly obscured by dust. We quantify this trend and establish an empirical calibration for predicting A(Ha) with a combination of H-alpha/UV ratio, stellar mass and EW(Ha), with which we can successfully reduce the systematic uncertainties accompanying the simple H-alpha/UV approach by ~15-30%. The new recipes proposed in this study will provide a convenient tool for predicting dust extinction level of galaxies particularly when Balmer decrement is not available. By comparing A(Ha) (derived with Balmer decrement) and A(UV) (derived with IR/UV luminosity ratio) for a subsample of galaxies for which AKARI FIR photometry is available, we demonstrate that more massive galaxies tend to have higher extra extinction towards the nebular regions compared to the stellar continuum light. Considering recent studies reporting smaller extra extinction towards nebular regions for high-redshift galaxies, we argue that the dust geometry within high-redshift galaxies resemble more like low-mass galaxies in the nearby Universe.Comment: 14 pages, 14 figures, Accepted for publication in MNRA

    Analysis of the interaction between particles and gliding arc discharge in a spouted bed reactor

    Get PDF
    In this paper, the interaction between particles and gliding arcs in a spouted bed reactor combined with gliding arc discharge was investigated using a high-speed camera. Based on the images captured by the camera, we evaluated the retention time for gliding arcs, the contact frequency of particles with the gliding arc, and the passage area of the gliding arc until its disappearance. The effects of the gas flow rate; electrode angle, which is same as the cone angle of the spouted bed; and applied voltage of gliding arcs were investigated. The retention time for gliding arcs was extended by a high applied voltage, the passage area was increased at a high gas flow rate, and the contact frequency was increased by decreasing the electrode angle. The results obtained here can support the optimization of particle treatment processes in a spouted bed with gliding arc discharge

    VEGF-A induces tumor and sentinel lymph node lymphangiogenesis and promotes lymphatic metastasis

    Get PDF
    The mechanisms of tumor metastasis to the sentinel lymph nodes are poorly understood. Vascular endothelial growth factor (VEGF)-A plays a principle role in tumor progression and angiogenesis; however, its role in tumor-associated lymphangiogenesis and lymphatic metastasis has remained unclear. We created transgenic mice that overexpress VEGF-A and green fluorescent protein specifically in the skin, and subjected them to a standard chemically-induced skin carcinogenesis regimen. We found that VEGF-A not only strongly promotes multistep skin carcinogenesis, but also induces active proliferation of VEGF receptor-2–expressing tumor-associated lymphatic vessels as well as tumor metastasis to the sentinel and distant lymph nodes. The lymphangiogenic activity of VEGF-A–expressing tumor cells was maintained within metastasis-containing lymph nodes. The most surprising finding of our study was that even before metastasizing, VEGF-A–overexpressing primary tumors induced sentinel lymph node lymphangiogenesis. This suggests that primary tumors might begin preparing their future metastatic site by producing lymphangiogenic factors that mediate their efficient transport to sentinel lymph nodes. This newly identified mechanism of inducing lymph node lymphangiogenesis likely contributes to tumor metastasis, and therefore, represents a new therapeutic target for advanced cancer and/or for the prevention of metastasis

    Lifetime reduction of a quantum emitter with quasiperiodic metamaterials

    Get PDF
    Enhancement of light-matter interaction of a quantum emitter with subwavelength quasiperiodic metamaterials is proposed and demonstrated. The quasiperiodic metamaterials consist of subwavelength metal-dielectric multilayers, which are arranged into a Fibonacci lattice. The influence of Fibonacci metamaterials (FM) on the dipole emission is analyzed with a semiclassical model. The local density of states near FM is evaluated and a characteristic mode in higher wave numbers is revealed; a strong enhancement of the decay rate was predicted. A lifetime measurement is carried out and a reduction of lifetime of quantum dots on the surface of FM is observed. The enhancement of light-matter interaction arises from the localized latticelike state inherent for self-similar quasiperiodic order

    ERO R1 in CL0939+4713 field - Evidence for an S0-like galaxy at z \sim 1.5

    Full text link
    We present further observations of the extremely red object ERO J094258+4659.2, identified by \citet{iye00} as ERO R1 in their deep images of the cluster A851. We estimate its redshift independently by eight-band photometric redshift determination and cross-correlation of a new H-band spectrum with the optical spectra of local E/S0 galaxies, and conclude that it lies at z1.5z \sim 1.5. Although its colors are consistent both with an elliptical galaxy and an S0 galaxy at that redshift, its elongated shape and exponential luminosity profile suggest the presence of an evolved stellar disk component. We rule out the possibility that these properties are strongly influenced by gravitational lensing by the foreground cluster, and therefore conclude that this object is more likely to be an S0-like galaxy, rather than a lensed elliptical. The H-band spectrum does not show strong Hα\alpha emission and the star formation rate therefore appears to be very modest. The presence of such a galaxy with an apparently relaxed disk of stars at this high redshift provides a new and strong constraint on theoretical models which aim to explain the formation and evolution of galaxies.Comment: 23 pages, 9 figures, Submitted to the Astrophysical Journa
    corecore