A5086052260- Lightning and Electromagnetic Phenomena
- Ionosphere and magnetosphere dynamics
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Planetary Science and Exploration
- Fire effects on ecosystems
- Spacecraft Design and Technology
- Earthquake Detection and Analysis
- Organic and Molecular Conductors Research
- Solar and Space Plasma Dynamics
- Atmospheric aerosols and clouds
- Astro and Planetary Science
- Crystallography and molecular interactions
- Perovskite Materials and Applications
- Meteorological Phenomena and Simulations
- Impact of Light on Environment and Health
- Organic Electronics and Photovoltaics
- Remote Sensing and Land Use
- Atmospheric Ozone and Climate
- Space exploration and regulation
- Tropical and Extratropical Cyclones Research
- High voltage insulation and dielectric phenomena
- Inertial Sensor and Navigation
- Satellite Communication Systems
- Remote Sensing in Agriculture
Hokkaido University
2015-2024
Sakakibara Hospital
1994-2024
Nippon Dental University
2022
Sapporo Science Center
2018-2021
Nippon Soken (Japan)
2006-2019
Global Science & Technology (United States)
2016-2019
Graduate School USA
2014-2019
Tokyo University of Science
2019
Gifu University
2019
Cosmos Corporation (United States)
2014-2018
The structural and electrical properties of a metal-halide cubic perovskite, CH(3)NH(3)SnI(3), have been examined. band structure, obtained using first-principles calculation, reveals well-defined gap at the Fermi level. However, temperature dependence single-crystal conductivity shows metallic behavior down to low temperatures. thermoelectric power is also over whole range, large positive value indicates that charge transport occurs with concentration hole carriers. this as-grown crystal...
Molecular ferroelectric crystals have attracted growing interest as potential alternatives to conventional lead-based ceramic ferroelectrics. We recently discovered that a class of compounds known plastic can show multiaxial ferroelectricity, which allows performance even in polycrystalline forms. Here, we report new plastic/ferroelectric ionic molecular exhibit remarkably small coercive electric fields at room temperature. The easily switchable polarization enables low-voltage switching...
Observations of optical phenomena at high altitude above thunderstorms using a multichannel high‐speed photometer and image intensified CCD cameras were carried out Yucca Ridge Field Station (40°40′N, 104°, 56′W), Colorado as part the SPRITES'95 campaign from 15 June to August 6, 1995. These new measurements indicate that diffuse flashes with duration < 1 ms horizontal scale ∼100–300 km occur 75–105 in lower ionosphere just after onset cloud‐to‐ground lightning discharges, but preceding...
We report the global transient luminous event (TLE) distributions and rates based on Imager of Sprites Upper Atmospheric Lightning (ISUAL) experiment onboard FORMOSAT‐2 satellite. ISUAL observations cover 45°S to 25°N latitude during northern summer 25°S 45°N winter. From July 2004 June 2007, recorded 5,434 elves, 633 sprites, 657 halos, 13 gigantic jets. Surprisingly, elve is dominant type TLEs, while sprites/halos are a distant second. Elve occurrence rate jumps as sea surface temperature...
We fabricated high-performance single crystal organic field-effect transistors (SC-OFETs) based on dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]-thiophene (DNTT). Among various device geometries and contact types, best performance is obtained for a lamination-type SC-OFET composed of Cytop-treated SiO2 gate dielectric top-contact gold/tetrathiafulvalene-tetracyanoquinodimethane electrodes, which results in hysteresis-free characteristics with optimum mobility 8.3 cm2/V s an on/off ratio &gt;108....
The use of unmanned aerial vehicle (UAV)-based spectral imaging offers considerable advantages in high-resolution remote-sensing applications. However, the number sensors mountable on a UAV is limited, and selecting optimal combination bands complex but crucial for conventional UAV-based multispectral systems. To overcome these limitations, we adopted liquid crystal tunable filter (LCTF), which can transmit selected wavelengths without need to exchange optical filters. For calibration...
Plastic crystals represent a unique compound class that is often encountered in molecules with globular structures. The highly symmetric cubic crystal structure of plastic endows these materials multiaxial ferroelectricity allows three-dimensional realignment the polarization axes crystals, which cannot be achieved using conventional molecular ferroelectric low symmetry. In this work, we focused our attention on malleability as another characteristic feature crystals. We have synthesized new...
AKATSUKI is the Japanese Venus Climate Orbiter that was designed to investigate climate system of Venus. The orbiter launched on May 21, 2010, and it reached December 7, 2010. Thrust applied by orbital maneuver engine in an attempt put into a westward equatorial orbit around with 30-h period. However, this operation failed because malfunction propulsion system. After failure, spacecraft orbited Sun for 5 years. On 2015, once again approached insertion successful, whereby apoapsis ~440,000 km...
Molecules in crystals often suffer from severe limitations on their dynamic processes, especially those involving large structural changes. Crystalline compounds, therefore, usually fail to realize potential as dielectric materials even when they have dipole moments. To enable polar molecules undergo processes and provide with properties, weakly bound charge-transfer (CT) complex been exploited a molecular architecture where the constituent some freedom of which contribute properties...
Fine control of p-, n-, and ambipolar-type field-effect transistor (FET) operations is successfully demonstrated in prototypical single-crystal organic FETs with use chemically tunable nature Fermi energy tetrathiafulvalene-tetracyanoguinodimethane-based metal electrodes. Carrier-type preference rectifying the organic-organic contacts are revealed terms FET as well all-organic Schottky diode characteristics.
From analyzing the distribution of transient luminous events (TLEs) registered by Imager Sprites and Upper Atmospheric Lightning payload on FORMOSAT‐2 satellite, we deduced synoptic‐scale factors that control occurrence TLEs. For low‐latitude tropical regions (25°S ∼ 25°N), 84% TLEs were found to occur over Intertropical Convergence Zone South Pacific exhibited a seasonal variation migrates north south with respect equator. midlatitude (latitudes beyond ±30°), congregated Ocean, Atlantic...
The electromagnetic pulses (EMP) from tropospheric lightning produce transient luminous events (TLEs), known as elves, in the 80–90 km region above lightning. luminosity is evidence that EMP carries sufficient electric field to excite optical emissions at these altitudes; however, it still unknown whether ionize atmosphere. first multiwavelength, quantitative observatory on a free‐flying satellite dedicated observing TLEs, Imager of Sprites and Upper Atmospheric Lightning (ISUAL) instrument...
Electron energies and the strength of electric fields in sprites are deduced for five selected events, which were recorded by space‐borne instrument called ISUAL (Imager Sprites Upper Atmospheric Lightning; a payload on FORMOSAT‐2 satellite). From derived peak intensity ratios spectrophotometer channel 2 (centered at 337 nm) 3 391.4 these sprites, average characteristic electron found to be range 6.2–9.2 eV 4.5–6.5 eV, respectively. The estimated E/N 40–60 km is 243–443 Td field 2.1–3.7...
Gamma radiation observed in space has been associated with lightning flashes thunderstorms. These special do not appear to be the large and energetic positive ground that also produce sprites. Considerations of gamma ray attenuation air indicate such may at sufficient altitude enable their escape space. High‐altitude intracloud lightning, most prevalent tropics where tropopause is high, a necessary source.
Well-controlled carrier doping was performed in pentacene thin-film transistors (TFTs) by depositing additional organic acceptor (F4TCNQ) layers on top of existing channels. The concentration could be predefined changing the area covered with layer, which provides control threshold gate voltage, while keeping both field-effect mobility (∼1.0cm2∕Vs) and current on/off ratio (&gt;105). transport properties these devices are discussed terms trap release model for doped TFTs.
The organic field-effect transistors (OFETs) composed of HMTTF single crystals as channel semiconductors exhibit a mobility exceeding 10 cm2/Vs. To achieve this high device performance we found it necessary to optimize carrier injections by using thin films tetrathiafulvalene–tetracyanoquinodimethane (TTF-TCNQ) charge-transfer complexes the source/drain electrodes.
This article reports the first high time resolution measurements of gigantic jets from Imager Sprites and Upper Atmospheric Lightning (ISUAL) experiment. The velocity upward propagating fully developed jet stage was ∼10 7 m s −1 , which is similar to that observed for downward sprite streamers. Analysis spectral ratios emissions gives a reduced E field 400–655 Td average electron energy 8.5–12.3 eV. These values are higher than those in sprites but predicted by streamer models, implies...
The Akatsuki spacecraft of Japan was launched on May 21, 2010. planned to enter a Venus-encircling near-equatorial orbit in December 7, 2010; however, the Venus insertion maneuver has failed, and at present is orbiting Sun. There possibility conducting an again several years later. main goal mission understand Venusian atmospheric dynamics cloud physics, with explorations ground surface interplanetary dust also being themes. angular motion roughly synchronized zonal flow near base for 20...
The Imager for Sprites and Upper Atmospheric Lightning (ISUAL) on the FORMOSAT‐2 spacecraft observes Transient Luminous Events (TLE) like sprites, elves, halos from space. We analyzed that were observed in Central America close enough to ELF/VLF receivers allowed determination of polarity parent lightning. All created by negative cloud ground lightning (−CG) strokes occurred almost exclusively over open water. Only three out 31 events happened land. conclude American region seems be special...
The ISUAL experiment on the FORMOSAT‐2 satellite has confirmed existence of ionization and Lyman‐Birge‐Hopfield (LBH) band emissions in elves. In this paper, an in‐depth study recorded elves was carried out. Numerical simulation results based electromagnetic finite difference time domain (FDTD) model between 185–800 nm their spatial‐temporal evolution are presented. To account for effect atmospheric attenuation, three major attenuation mechanisms: O 2 , 3 molecular Rayleigh scattering...