A5035269331- Lightning and Electromagnetic Phenomena
- Semiconductor materials and devices
- Multiferroics and related materials
- Ferroelectric and Piezoelectric Materials
- Ionosphere and magnetosphere dynamics
- Fire effects on ecosystems
- Mobile Ad Hoc Networks
- Network Traffic and Congestion Control
- Caching and Content Delivery
- Magneto-Optical Properties and Applications
- Opportunistic and Delay-Tolerant Networks
- Multimedia Communication and Technology
- Peer-to-Peer Network Technologies
- Copper Interconnects and Reliability
- Meteorological Phenomena and Simulations
- IPv6, Mobility, Handover, Networks, Security
- Precipitation Measurement and Analysis
- Magnetic and transport properties of perovskites and related materials
- Metal and Thin Film Mechanics
- Soil Moisture and Remote Sensing
- Network Security and Intrusion Detection
- Wireless Communication Networks Research
- Electrical Fault Detection and Protection
- Video Analysis and Summarization
- Power Line Communications and Noise
Daiichi-Sankyo (Japan)
2024
Kobe City College of Technology
2012-2023
Osaka University
1987-2023
Kyoto University
2005-2023
RIKEN
2023
Nagoya University
2014-2023
Kindai University
2023
Japan Atomic Energy Agency
2023
Kyoto Tachibana University
2021-2023
Gifu University
2023
Abstract Two types of high-energy events have been detected from thunderstorms. One is “terrestrial gamma-ray flashes” (TGFs), sub-millisecond emissions coinciding with lightning discharges. The other minute-lasting “gamma-ray glows”. Although both phenomena are thought to originate relativistic runaway electron avalanches in strong electric fields, the connection between them not well understood. Here we report unequivocal simultaneous detection a glow termination and downward TGF, observed...
Abstract We have been developing an LF sensor network called Broadband Observation for Lightning and Thunderstorm (BOLT), to image the structure of lightning discharges in 3D using time arrival (TOA) technique. This paper documents initial results characteristics BOLT source locations further understanding radiation associated with lightning. Theoretical reduced Chi‐square distribution fitted observation data indicates a root mean square (rms) timing error about 200 ns each sensor. Monte...
During a winter thunderstorm on 24 November 2017, strong burst of gamma rays with energies up to $\ensuremath{\sim}10\text{ }\text{ }\mathrm{MeV}$ was detected coincident lightning discharge, by scintillation detectors installed at the Kashiwazaki-Kariwa Nuclear Power Station sea level in Japan. The had subsecond duration, which is suggestive photoneutron production. leading part resolved into four intense gamma-ray bunches, each low-frequency radio pulse. These bunches were separated...
The Lightning Research Group of Osaka University has been developing and improving the VHF broadband digital interferometer, which locates impulsive radiation sources caused by lightning discharges with extremely high time resolution in three dimensions. As a result observations during 2006–2007 monsoon season Darwin, Australia, cloud flashes accompanied K processes are clearly visualized dimensions resolution. In late stage flashes, negative recoil streamers changes propagate along same...
Abstract During 2017–2018 winter operation of the Gamma‐Ray Observation Winter Thunderclouds experiment in Japan, two downward terrestrial gamma‐ray flashes (TGFs) that triggered atmospheric photonuclear reactions were detected. They took place during thunderstorms on 5 December 2017 and 9 January 2018 at Kanazawa, Ishikawa Prefecture, Japan. Each event coincided with an intracloud/intercloud discharge, which had a negative‐polarity peak current higher than 150 kA. Their radio waveforms...
Abstract Around 17:00 on January 12, 2020 (UTC), radiation detectors installed at two locations with a 1.35 km separation in Kanazawa City, Japan, captured total of four gamma‐ray enhancements. The first pair was simultaneously observed the 17:03 and were abruptly terminated by lightning discharge. remaining enhancements also nearly 3 min later, one them another At last termination, downward terrestrial flash negative energetic in‐cloud pulse observed. Both pairs associated thundercloud...
Abstract Winter thunderstorms in Japan have been recognized as an ideal target to observe high‐energy atmospheric phenomena thanks low‐charge‐center cloud structures. During four winter seasons (from 2016 October 2020 March), seven downward terrestrial gamma‐ray flashes (TGFs) were detected by and broadband low‐frequency (LF: 0.8–500 kHz) monitors. All the TGFs took place at initial stage of lightning flashes. Based on LF observation, present study can be classified into two types:...
Abstract Gamma‐ray glows are observational evidence of relativistic electron acceleration due to the electric field in thunderclouds. However, it is yet be understood whether such electrons contribute initiation lightning discharges. To tackle this question, we started citizen science “Thundercloud Project,” where map radiation measurements from winter thunderclouds along Japan's sea coast area. We developed and deployed 58 compact gamma‐ray monitors at end 2021. On 30 December 2021, five...
Bi-layer-structured multiferroic Bi5Ti3FeO15 (BTFO15) thin films have been fabricated on the Pt/TiO2/SiO2/Si substrate at a low temperature of ∼520 °C and various O2 pressures 0.01–0.12 Torr by pulsed laser deposition, their dielectric, ferroelectric, magnetic properties characterized. The X-ray diffraction patterns BTFO15 indicate mixed phases pyrochlore Bi2Ti2O7. (520 0.12 Torr) show good ferroelectric hysteresis loop, large double remanent polarization (2Pr) 32 µC/cm2 was obtained maximum...
We have investigated effects of the postmetallization annealing and electric field application on ferroelectric properties BiFeO3 thin films prepared by chemical solution deposition. The leakage current is reduced after although crystallinity polycrystalline unchanged. In addition, double coercive at about 90 kV/cm annealing, while remanent polarization μC/cm2 almost same 80 K. considered to lead improvement contact between film Pt electrode or reduction in defects near interface electrode....
Ruthenium films were prepared on SiO2/Si substrates by liquid source metalorganic chemical vapor deposition (LSMOCVD) using Ru(C11H19O2)3 (tris (dipivaloylmethanato) ruthenium: Ru(dpm)3) precursor dissolved in C4H8O (tetrahydrofuran: THF) solvent as a source. The deposited consisted of metallic ruthenium single phase under all conditions studied and could be directly SiO2 without having distinct incubation time. We elucidated that the mechanism was controlled an oxygen-controlled surface...
The adsorption of tungsten hexafluoride (WF6) and monosilane (SiH4) in selective chemical-vapor deposition (CVD) (W) is investigated situ using Fourier-transform infrared reflection transmission absorption spectroscopy (FTIR RAS TMS). selectivity for W growth found to originate from the dissociation SiH4 on a surface. That is, dissociates surface form Si-containing adsorbed species when exposed at temperatures higher than 110 °C, whereas does not dissociate SiO2 On other hand, surfaces are...
Abstract The charge distributions in a thundercloud play an important role the initiation and propagation of lightning discharges. To further understand effects on discharge, authors conducted very high-frequency (VHF) observation campaign during 2006/07 monsoon Darwin, Australia, using VHF broadband digital interferometer (DITF). A C-band polarimetric weather radar to estimate precipitation profiles such as hydrometeor classification was operated by Bureau Meteorology (BOM) Research Centre....
Mirogabalin besilate is an α2δ ligand that developed by Daiichi Sankyo as a drug for the treatment of neuropathic pain. This compound has intricate and highly strained bicyclo[3.2.0]-heptane skeleton having three consecutive asymmetric centers on ring, therefore, it presents formidable synthetic challenges. In this study, we present efficient manufacturing process mirogabalin, employing organocatalytic kinetic resolution racemic bicyclic ketone key step. synthesis commences with construction...
The Hall coefficient and electric conductivity of black phosphorus prepared by the bismuth-flux method were measured at low temperatures. It is found that shows log T-like behaviour below about 5 K changes its sign from plus to minus around 7 with decreasing temperature. These results can be analysed successfully on basis a three-carrier model, in which bulk holes, variable-range-hopping holes two-dimensional electrons take part conduction temperatures, except case strong magnetic fields K....
Photoconduction of elemental black phosphorus has been investigated for the first time in spectral range from 1.5 µm to 5.5 µm, including its fundamental absorption edge. It found that shows a broad response edge visible region and linear light intensity, which fairly even at room temperature. These results suggest can be applicable IR detecting devices. In addition, direct allowed transition was confirmed temperature dependence measured.
We report the development of a novel synthetic method to access key intermediate in synthesis edoxaban. The main features new are an improvement approach for chiral bromolactone, application interesting cyclization reaction utilizing neighboring group participation construct differentially protected 1,2-cis-diamine, and implementation plug-flow reactor technology enable unstable on multihundred kilogram scale. overall yield preparation edoxaban was significantly increased by implementing...
Abstract In the presence of bis(maleic anhydride)(norbornene)palladium as a catalyst, two 1-alkene molecules, R–CH2–CH=CH2, were added regioselectively to dimethyl acetylenedicarboxylate in syn addition mode give 2-(2-alkenyl)-3-alkylmaleates, R–CH=CH–CH2–C(COOCH3)=C(COOCH3)–CH2CH2CH2-R under moderate condition (40–45°C) chloroform.
We have been designing and developing a 3-D lightning location system based on the broadband digital interferometry technique in LF bands. The interferometer (LF DITF) consists of four or more receivers which detect electromagnetic (EM) waves wide frequency range from 400 Hz to 1 MHz associated with discharges. Since each receiver detects EM LF, DITF is able locate discharges several hundred kilometers. During winter season 2010-2011, simultaneous observation DITF, VHF Rogowski coils was...
We have investigated the influences of surface texture and Bi/Fe ratio on electric property BiFeO3 thin films prepared by chemical solution deposition. All a rosette structure, which consists circular regions with crystals outer amorphous phase. Circular tend to increase an in ratio. Leakage current increases area roughness as well On other hand, remanent polarization ratio, but decreases film using 20 mol % Bi-excess owing mixed Consequently, 10 gives best ferroelectric for more its is 85 µC/cm2.
The insertion effect of Bi -excess layers on stoichiometric BiFeO 3 thin films prepared by chemical solution deposition is investigated. A film with both the top and bottom surface shows improved crystallinity remanent polarization 65 μC/cm 2 at 80 K, which larger than for same process using solution. These results are attributed to reduction imperfect crystal interface between electrode. By inserting Bi-excess layers, saturated magnetization all becomes smaller that interfaces an effective...