A5033847068- Geological and Geochemical Analysis
- Pulsars and Gravitational Waves Research
- Geochemistry and Geologic Mapping
- Solar and Space Plasma Dynamics
- earthquake and tectonic studies
- Ionosphere and magnetosphere dynamics
- Geology and Paleoclimatology Research
- Geomagnetism and Paleomagnetism Studies
- Gamma-ray bursts and supernovae
- Robotic Locomotion and Control
- Prosthetics and Rehabilitation Robotics
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Earthquake Detection and Analysis
- Seismic Waves and Analysis
- Seismology and Earthquake Studies
- Astrophysical Phenomena and Observations
- Earthquake and Disaster Impact Studies
- Astro and Planetary Science
- Nuclear Physics and Applications
- Cosmology and Gravitation Theories
- Geophysics and Sensor Technology
- Nuclear reactor physics and engineering
- Isotope Analysis in Ecology
- Geochemistry and Elemental Analysis
Kansai University
2023
University of Toyama
2020-2023
The University of Tokyo
2020-2023
Hitachi (Japan)
2023
Yamato University
2023
Kyoto University
2013-2022
Graduate School USA
2015-2018
Tohoku University
2016
Waseda University
2007-2014
KAGRA is a newly built gravitational wave observatory, laser interferometer with 3 km arm length, located in Kamioka, Gifu, Japan. In this series of articles, we present an overview the baseline KAGRA, for which finished installing designed configuration 2019. This article describes method calibration (CAL) used reconstructing signals from detector outputs, as well characterization (DET). We also review physical environmental monitors (PEM) system and geophysics (GIF). Both are...
We have developed new analytical procedures to measure precise and accurate 238 U– 206 Pb 235 207 ages for young (~ 1 Ma) zircons using laser ablation‐ ICP ‐mass spectrometry. For zircons, both careful correction the background counts analysis of very small Pb/U ratios (i.e., Pb/ U < 0.00016 0.0001 Ma zircons) are highly desired. background, contribution signal intensities analytes, especially residual Pb, was defined through ablation synthesised (ablation blank) containing negligible Pb....
Precise zircon U–Pb age determinations have been made on Plešovice using laser ablation-multiple ion counting-inductively coupled plasma-mass spectrometry (LA-MIC-ICP-MS).
Abstract KAGRA is a newly build gravitational wave observatory, laser interferometer with 3 km arm length, located in Kamioka, Gifu, Japan. In this paper, one of series articles featuring KAGRA, we discuss the science targets projects, considering not only baseline (current design) but also its future upgrade candidates (KAGRA+) for near to middle term ($\sim$5 years).
Abstract The study of historical great geomagnetic storms is crucial for assessing the possible risks to technological infrastructure a modern society, caused by extreme space–weather events. normal benchmark has been storm 1859 September, so-called “Carrington Event.” However, there are numerous records another in 1872 February. This storm, which occurred about 12 years after Carrington Event, resulted comparable magnetic disturbances and auroral displays over large areas Earth. We have...
The humanoid robot, WABIAN-2R, has achieved human-like walking with knee-stretched, heel contact and toe off motions by using a foot mechanism passive joint. However, the structure is different from human's. In this paper, we describe new capable of mimicking human's arch to figure out function structure. Especially, developed mimics elastic properties change height during walking. consists joint in internal toe, external arch. We conducted several experiments clarified quantitatively. As...
We evaluate worldwide low-latitude auroral activity associated with the great magnetic storm of September 1909 for which a minimum Dst value −595 nT has recently been determined. From observations, we calculate that equatorward boundary oval in event was range from 31°–35° invariant latitude (assuming height 400 km) to 37°–38° (800 km). These locations compare satellite-based observations precipitating electrons down 40° March 1989 its comparable −589 nT. According Japanese records, bluish...
The Carrington event is considered to be one of the most extreme space weather events in observational history within a series magnetic storms caused by interplanetary coronal mass ejections (ICMEs) from large and complex active region (AR) emerged on solar disk. In this article, we study temporal spatial evolutions source sunspot visual aurorae, compare storm with other basis their evolution. Sunspot drawings Schwabe, Secchi, describe position morphology AR at that time. Visual auroral...
Abstract KAGRA, the kilometer-scale underground gravitational-wave detector, is located at Kamioka, Japan. In April 2020, an astrophysics observation was performed KAGRA detector in combination with GEO 600 detector; this operation called O3GK. The optical configuration O3GK based on a power-recycled Fabry–Pérot–Michelson interferometer; all mirrors were set room temperature. duty factor of approximately 53%, and displacement sensitivity 1 × 10−18 ${\rm m}/\sqrt{\rm {Hz}}$ 250 Hz....
We have developed a new biped foot mechanism capable of detecting ground surface to realize stable walking on uneven terrain. The size the is 160 mm × 277 and its weight 1.5 kg. system consists four spikes each which has an optical sensor detect height. makes support polygon terrain by using three or spikes. conducted several experiments outdoor that slope 7.0 degrees maximum height 15 bumps, effectiveness confirmed.
Dim red aurora at low magnetic latitudes is a visual and recognized manifestation of storms. The great low-latitude auroral displays seen throughout East Asia on 1770 September 16–18 are considered to manifest one the greatest Recently found, 111 historical documents in attest that these appeared succession for almost nine nights during 10–19 latitude areas (<30°). This suggests duration storm much longer than usual. Sunspot drawings from reveal sunspot were twice as large those observed...
Low-pressure/high-temperature metamorphic rocks exposed in the western part of Ryoke belt (Iwakuni–Yanai area, SW Japan) include a section with increasing temperature conditions from ∼425 to 880°C. We use this setting explore evolution monazite grain size, texture and composition, variations whole-rock composition 11 metapelite, metapsammite or metachert samples collected along field gradient. Monazite size increases rising grade, regardless composition. From low- high-grade we infer: (1)...
We review observations of solar activity, geomagnetic variation, and auroral visibility for the extreme storm on 1872 February 4. The (referred to here as Chapman-Silverman storm) apparently originated from a complex active region moderate area (\approx 500 {\mu}sh) that was favorably situated near disk center (S19{\deg} E05{\deg}). There is circumstantial evidence an eruption this at 9--10 UT 3, based location, complexity, evolution region, reports prominence activations, which yields...
Zircons collected from a granitic pluton provide evidence of serial growth events with specific mechanisms, crystallization temperatures and U–Pb ages, revealing details the sequential formation process intrusion through emplacement to crystallization/solidification. The have been identified by: 1) study internal structure zircon using cathodoluminescence, 2) deriving Ti–in–zircon thermometry 3) age dating structure. magmatic zircons Toki granite, central Japan, show two kinds in their...
ABSTRACT In late 1940 March, at least five significant solar flares were reported. They likely launched interplanetary coronal mass ejections (ICMEs), and associated with one of the largest storm sudden commencements (SSCs) since 1868, resulting in space weather hazards that would have societal impacts should it occur today. The initial activity is a proton event. Afterwards, another flare was reported eastern quadrant (N12 E37-38) 11:30–12:30 ut on March 23, magnetic crochets (up to ≈ |80|...
Abstract Solar activity generally exhibits cyclic behavior in terms of sunspot group number and positions every ≈11 yr. These data have therefore played key roles numerous analyses solar–terrestrial physics. However, their reconstructions prior to the 1830s remained controversial included significant gaps, especially from 1720s 1740s. Therefore, this study reviewed contemporary observations for 1727–1748 add several forgotten records by Van Coesfelt 1728–1729, Dûclos 1736, Martin 1737,...
Although knowing the occurrence frequency of severe space weather events is important for a modern society, it insufficiently known due to lack magnetic or sunspot observations, before Carrington event in 1859 as one largest during last two centuries. Here, we show that storm occurred on 8 March 1582 based auroral records East Asia. The equatorward boundary visibility reached 28.8{\deg} latitude. oval estimated be 33.0{\deg} invariant latitude (ILAT), which comparable storms 25/26 September...
Aims . Historical records provide evidence of extreme magnetic storms with equatorward auroral extensions before the epoch systematic observations. One significant storm occurred on February 15, 1730. We scale this extension and contextualise it based contemporary solar activity. Methods examined historical in East Asia computed latitude (MLAT) observational sites to storms. also compared them Southern Europe. sunspot observations reconstruct detailed activity between 1729 1731. Results show...
The appropriateness of Zr as an 'immobile element' during garnet–hornblende (Grt–Hbl) vein formation potentially caused by the Cl–rich fluid or melt infiltration under upper amphibolite facies condition is examined. sample used a Grt–Hbl from Brattnipene, Sør Rondane Mountains, East Antarctica that discordantly cuts gneissose structure mafic gneiss.Modal analysis wall rock minerals combined with quantitative determination their contents reveals most whole–rock resides in zircon whereas ~ 5%...
Four volcanic glass samples on the INternational focus group Tephrochronology And Volcanism (INTAV) sample mount described by Kuehn et al. (2011) were analyzed to establish a new methodology for measurement of major and trace elements in Quaternary tephras femtosecond laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). NIST SRM 610 612 glasses used calibration 58 from Li U two rhyolitic (Lipari obsidian ID3506 Old Crow tephra) phonolitic Sheep Track tephra. In addition...
Major solar eruptions occasionally direct interplanetary coronal mass ejections (ICMEs) to Earth and cause significant geomagnetic storms low-latitude aurorae. While single extreme are of threats the modern civilization, appear in sequence and, acting synergistically, 'perfect storms' at Earth. The stormy interval January 1938 was one such cases. Here, we analyze contemporary records reveal its time series on their source active regions, eruptions, ICMEs, storms, aurorae, cosmic-ray (CR)...
Abstract Zircon is resistant to alteration over a wide range of geological environments, and isotopic ratios within the mineral provide constraints on ages their parental magmas. Trace element compositions in zircon are also expected reflect those parent magmas, have potential as essential indicators for host rocks. Because most detrital zircons that accumulate at river mouths derived primarily from granitoids, classification granitoids potentially meaningful. This study employs conventional...
Many researchers have studied on walking stability controls for biped robots. Most of them are highly accurate acceleration based the mechanics model robot. However, control algorithms difficult to be used human-carrying robots due modeling errors. In previous report, we proposed landing pattern modification method, but it had a problem that foot impact increased when cycle was short. So, propose new terrain-adaptive reducing landing-impact force. To increase concave terrain adaptation, set...