A5079799419- Atmospheric chemistry and aerosols
- Vehicle emissions and performance
- Mass Spectrometry Techniques and Applications
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- Analytical chemistry methods development
- Advanced Aircraft Design and Technologies
- Advanced Chemical Physics Studies
- Analytical Chemistry and Sensors
- Atmospheric Ozone and Climate
- Molecular Spectroscopy and Structure
- Air Traffic Management and Optimization
- Spectroscopy and Laser Applications
- Advanced Chemical Sensor Technologies
- Advanced Combustion Engine Technologies
- Crystallography and molecular interactions
- Ion-surface interactions and analysis
- Spectroscopy and Quantum Chemical Studies
- Chemical Thermodynamics and Molecular Structure
- Toxic Organic Pollutants Impact
- Water Quality Monitoring and Analysis
- Scientific Measurement and Uncertainty Evaluation
- Quantum chaos and dynamical systems
- Catalytic Processes in Materials Science
- stochastic dynamics and bifurcation
Tokyo Metropolitan University
2016-2023
Tokyo Institute of Technology
2005-2017
Texas A&M University
2017
National Institute for Environmental Studies
2016
Materials Resources (United States)
2014
Keio University
1981-1983
Significance Aromatic hydrocarbons account for 20 to 30% of volatile organic compounds and contribute importantly ozone secondary aerosol (SOA) formation in urban environments. The oxidation toluene, the most abundant aromatic compound, is believed occur mainly via OH addition, primary peroxy radical (RO 2 ) formation, ring cleavage, leading SOA. From combined experimental theoretical studies, we show that cresol dominant, while RO production negligible. Our work reveals subsequent reactions...
Dispersed fluorescence and IR dip spectra of seven conformers tyramine were measured in a supersonic jet. Observed vibrational bands are assigned based on quantum chemical calculations. The frequency out-of-plane CH bending the benzene ring shows characteristic shifts according to conformation Cβ−Cα, while that stretching methylene chain reflects N−Cβ. From these frequencies, assignments observed S1−S0 laser induced spectrum discussed.
Abstract. The characterization of ultrafine particle emissions from jet aircraft equipped with turbofan engines, which are commonly used in civil aviation, is an important issue the assessment impacts aviation on climate and human health. We conducted field observations aerosols carbon dioxide (CO2) near a runway at Narita International Airport, Japan, February 2018. condensation counter (UCPC) (CPC) unheated 350 ∘C heated operation modes to investigate contributions sub-10 nm size ranges...
Abstract The chemical composition and structure of fine aerosol particles with diameters less than 1 µm were analyzed in the spring 2011 at Fukue Island, Japan, using an quadrupole mass spectrometer (Q‐AMS, Aerodyne Research, Inc.) a time‐of‐flight secondary ion (TOF‐SIMS). Q‐AMS results similar to those previous studies conducted same location, suggesting that we observed is typical this site. Based on TOF‐SIMS results, classified into three types: Type A, which sulfate was covered organic...
A new spectroscopic method reveals the barrier and crucial role of direct photoionization in π → H site switching phenol–Ar.
The theoretical analysis of the velocity distribution function ions in weakly ionised gases is developed under condition induced dipole interaction between ion and molecule by using BGK approximation Boltzmann equation. derived functions valid for arbitrary reduced field strength E/N ion-neutral mass ratio m/M. results are compared with previous works Whealton Woo (1971), Wannier (1958), it found that predicted exhibits great power case nearly same mass. Also anisotropy investigated.
Time-resolved measurements of the concentration volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) in exhaust from a diesel vehicle fitted with an oxidation catalyst operated JE05 mode are performed at sensitivity 10 ppb using supersonic jet/resonance enhanced multi-photon ionization (Jet-REMPI) method. The concentrations benzene, naphthalene, phenol test measured before entering after exiting catalyst. total hydrocarbon (THC) is simultaneously constant volume...
IR spectra of phenol–CH4 complexes generated in a supersonic expansion were measured before and after photoionization. The spectrum ionization shows the free OH stretching vibration (νOH) structure neutral electronic ground state (S0) is assigned to π-bound geometry, which CH4 ligand located above phenol ring. cationic (D0) exhibits red shifted νOH band hydrogen-bonded structure, binds phenolic group. In contrast phenol–Ar/Kr, observed ionization-induced π → H migration has unity yield for...
Due to economic growth in China, emissions of gaseous components from factories and automobiles have been increasing, which has resulted severe air pollution. During the winter spring seasons, Japan, is on leeward side Asian continent, receiving end this increasingly problematic transboundary In study, mass concentration chemical particulate PM2.5 were continuously observed using an automatic analyzer at Kumamoto west coast Japan October 2014 March 2015. A greater number high days than...
The laser-induced fluorescence technique has been used to measure primary biological aerosol particles (PBAPs) in the atmosphere because of its ability classify origins based on combination excitation and detection wavelengths. However, information intensity related amounts fluorescent compounds airborne measured by this method is limited. Therefore, study, scattered signals from polystyrene latex (PSL) were observed simultaneously through fluorescence. ratio signal intensities individual...
The np gerade Rydberg states of acetylene were analyzed using two-photon resonance fluorescence excitation spectroscopy in the 72,000-93,000 cm(-1) energy region. npπ(1)Σ(g)(+) and npπ(1)Δ(g) series (n = 3-5) identified spectrum measured by monitoring C(2) d(3)Π(g)-a(3)Π(u) Swan system. Some vibronic bands assigned to npπ(1)Δ(g)-X̃(1)Σ(g)(+) transition on basis rotational analysis. 5pσ(1)Π(g) state was observed, which is first such observation an npσ(1)Π(g) series. Rotational analysis...
Abstract A sensitive, real-time, and molecular-selective analyzer using a resonance-enhanced multiphoton ionization/time-of-flight mass spectrometer (REMPI-TOFMS) was combined with the chamber method to measure emission factors of VOCs during painting. Temporal variation VOC successfully captured on site second time scale. Exact detailed assessment is realized molecular-dependent characteristics considered.
Aim at nanoscale mapping of organic matters, a novel Laser-SNMS instrument was developed by combining an FIB-TOF-SIMS with high lateral resolution and femtosecond laser power. The phase separation structure polystylene/polyhydroxystylene polymer alloy analyzed. In case conventional SIMS mode, the fragmentation signals two kinds were observed. obtained fragment signal has little quantity, acquired constituent distribution counts cannot be recognized polymers. Laser-SNMS, monomer each clearly...
Abstract Anthropogenic emissions of aerosols and trace gases from East Asia have significant impacts on air quality climate regional global scales. We conducted intensive measurements at a remote site (Cape Fuguei; 25.30°N, 121.54°E) in Taiwan the spring 2017, focusing chemical composition mixing state Asian outflow. A laser‐induced incandescence–mass spectrometric analyzer (LII‐MS) was used to measure internally or externally mixed with black carbon (BC). Offline analysis by transmission...
Abstract The electronic spectrum of benzo[e]pyrene (BeP) was recorded using resonance-enhanced multi-photon ionization (REMPI) spectroscopy. A number bands were observed and assigned to the origin band vibronic S1–S0 transition. Ab initio calculations performed assign vibrational structures in S1. BeP is well separated energy from benzo[a]pyrene (BaP), an isomer BeP, so BaP can be readily distinguished by REMPI method, despite having same mass.
Ion swarm transport is simulated by a Monte Carlo technique in the case of constant mean free time collision model with isotropic scattering after ions have been released into gas delta -function distribution space and steady-state velocity distribution. The behaviour coefficients investigated for ion-molecule mass ratios m/M 0.1, 1.0 10 under condition that field energy one hundred times greater than thermal energy. In particular, discussion given skewness excess density It also shown these...