A5101968789- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Air Quality Monitoring and Forecasting
- Atmospheric and Environmental Gas Dynamics
- Spectroscopy and Laser Applications
- Air Quality and Health Impacts
- Tropical and Extratropical Cyclones Research
- Meteorological Phenomena and Simulations
- Vehicle emissions and performance
- Remote Sensing and Land Use
- Atmospheric aerosols and clouds
- Advanced Chemical Sensor Technologies
- Odor and Emission Control Technologies
- Marine and coastal ecosystems
- Indoor Air Quality and Microbial Exposure
- Mercury impact and mitigation studies
- Catalytic Processes in Materials Science
- Environmental Changes in China
- Climate variability and models
- Environmental and Agricultural Sciences
- Luminescence Properties of Advanced Materials
- Precipitation Measurement and Analysis
- Flood Risk Assessment and Management
- Enzyme Structure and Function
- Calcium signaling and nucleotide metabolism
Waseda University
1994-2024
Sanyo-Onoda City University
2018
Nagoya University
2005-2015
Tokyo Metropolitan University
2002-2012
Tokyo Institute of Technology
2006-2008
Japan Science and Technology Agency
2003-2006
The University of Tokyo
1999-2002
Institute for Global Environmental Strategies
2001
Phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2 ) has critical functions in endosomes and lysosomes. We developed a method to define nanoscale distribution of PtdIns(3,5)P2 using freeze-fracture electron microscopy. GST-ATG18-4×FLAG was used label its binding phosphatidylinositol 3-phosphate (PtdIns(3)P) blocked by an excess the p40(phox) PX domain. In yeast exposed hyperosmotic stress, concentrated intramembrane particle (IMP)-deficient domains vacuolar membrane, which made close...
The daytime variation of hydroperoxy (HO 2 ) radical concentration was observed by an instrument based on laser‐induced fluorescence with NO addition at Oki Island, Japan, in July/August 1998. Although OH not detected due to the high detection limit instrument, HO determined 0.8 parts per trillion volume (pptv) (S/N = 2, integration time 1 min). On average, showed a maximum around 9 pptv early afternoon hours. During field campaign, chemical species and meteorological parameters such as O 3...
The observed midday maximum in the mixing ratio of HO 2 at Rishiri Island June 2000 was ∼10 pptv, but photochemical box model simulations overpredicted this location by an average 70%. This overestimation significant only when NO lower than 300 and coincident with overprediction NO/NO ratio. We detected several organoiodines, presumably emitted from seaweeds, propose presence IO radical. could reduce ratios via formation HOI that may subsequently be scavenged aerosols or lost photolysis also...
An instrument for measuring atmospheric peroxy radicals has been developed by chemical amplification/laser-induced fluorescence (PERCA/LIF) technique. The small concentration of is converted to the large amount NO2, which measured laser-induced instead luminol chemiluminescence. Several advantages, that is, high sensitivity, selectively, and fast time response, are expected use LIF NO2 measurement, in comparison with When using this system, simultaneous measurements available. present...
An instrument for measuring atmospheric nitrate radical (NO3) and dinitrogen pentoxide (N2O5) has been developed by a thermal conversion/laser-induced fluorescence (TC/LIF) technique. N2O5 is thermally decomposed converted to NO3, which measured laser-induced fluorescence. In situ, fast-response, sensitive measurement of NO3∕N2O5 expected use LIF. detecting dual-wavelength excitation at 622.96 618.81nm was adopted remove potential interference guarantee high selectivity. A high-power dye...
HO 2 (hydroperoxy) radical of unexpectedly high concentration around 3 ppt was measured by an instrument based on laser‐induced fluorescence with NO addition at Oki Island, Japan, the night August 9/10, 1998. We confirmed that interference atmospheric organic peroxy (RO ) radicals insignificant and concluded signal originated from nighttime . Model calculations constrained to ancillary measurements indicated RO were produced primarily via reactions ozone olefins, especially those internal...
Total OH reactivity was measured in the suburban area, Tokyo, July and August 2003, by use of a laser‐induced pump probe technique. More than 90% data loss rates were higher calculated values with simultaneously concentrations various trace species. The maximum difference between is 34.3%. However, this reduced to be 24.6% when using rate coefficient + NO 2 reaction recommended IUPAC 1997, which 40% larger most recently value (JPL 2002). We concluded that disagreement due uncertainty as well...
Abstract. N2O5 detection in the atmosphere has been accomplished using techniques which have developed during last decade. Most use a heated inlet to thermally decompose NO3, can be detected by either cavity based absorption at 662 nm or laser-induced fluorescence. In summer 2007, large set of instruments, were capable measuring NO3 mixing ratios, simultaneously deployed simulation chamber SAPHIR Jülich, Germany. Some these instruments measured ratios alternatively. Experiments focused on...
A new system that uses the total reactivity with ozone (RO3) was developed for measuring biogenic volatile organic compounds (BVOCs) emitted from vegetation into atmosphere. The decrease in caused by reaction VOCs monitored at ppbv level dual chemiluminescence detectors (CLDs) based on NO-O3 reaction. Ozone CLDs before and after reactor to correct fluctuations concentration. Such can remove interference water vapor. glass double-tube adopted as reactor. loss rate of wall typically (6 ± 3) ×...
We improved the thermal dissociation cavity attenuated phase shift spectroscopy (TD-CAPS) instrument to measure atmospheric total peroxy nitrates (PNs) and organic (ONs) continuously under condition of high NOx. In TD-CAPS, PNs ONs are dissociated in heated quartz tubes form NO2, NO2 concentration is measured by (CAPS). The original TD-CAPS system overestimates PN ON concentrations presence NO concentrations. Our laboratory experiments numerical simulations showed that main cause...
Measurements of oxidized nitrogen species, including peroxyacetyl nitrate (PAN), oxides (NO x ), nitric acid (HNO 3 and nonmethane hydrocarbons (NMHCs), were made along with ozone (O ) carbon monoxide (CO) at Rishiri Island, a remote island in northern Japan, as part the Island Study Oxidants Transport for Tropospheric Ozone (RISOTTO). Full seasonal observations O , CO, NMHCs, PAN, together data sets NO HNO 6 months reveal short‐term characteristics chemistry air masses northeast Asia....
The OH and HO 2 concentrations observed during the Observations at a Remote Island of Okinawa intensive field campaign (ORION99) were compared with those calculated by using ancillary observations as input parameters. Detailed comparisons performed for time resolution 10 min. During daytime, concentration levels variations basically well reproduced model calculations without including heterogeneous processes. On average, underestimated daytime only 20%. squared correlation coefficient...
Uptakes of sulfate and nitrate onto Asian dust particles during transport from the continent to Pacific Ocean were analyzed by using a single‐particle time‐of‐flight mass spectrometer. Observation was conducted at Tsukuba in Japan springtime 2004. Sulfate‐rich made their largest contribution ‘dust event’ middle April As result detailed analysis including backward trajectory calculations, it confirmed that components originating coal combustion internally mixed with particles. Even downstream...
Abstract To determine the reaction rate coefficient of volatile organic compounds with ozone, reduction ozone through a flow-tube reactor was measured by chemiluminescent detector. The validity method confirmed examination on isoprene. Consequently, 2,5-dimethylfuran, DMF, determined as (4.2 ± 0.9) × 10−16 cm3 molecule−1 s−1 for first time. It suggested that ozonolysis can be important fate DMF in atmosphere.