In order to understand the effect of secondary organic aerosols (SOAs) on induction of oxidative stress and inflammatory responses, we analyzed gene expression and protein production in human airway epithelial cells treated with some chemical components of SOAs, soluble extracts of SOAs and direct exposure to SOAs. As a result, it was suggested that treatment of epithelial cells with chemical components and soluble extracts of SOAs induced oxidative stress and inflammatory response. However, the effects differed with the type of chemical components and precursors of SOAs. Direct exposure of SOAs had no obvious effect on induction of oxidative stress and inflammatory responses.

View full abstract

To examine the usefulness of our cell exposure system for the evaluation of inflammatory responses, we analyzed the expression of inflammation-related genes in airway epithelial cells exposed to nitrogen dioxide using the cell exposure system. As a result, the expression change of inflammation-related genes induced by nitrogen dioxide could be clearly observed in lung carcinoma cells (A549), but not in primary cells (MucilAirTM). This result showed the usefulness of the cell exposure system for the evaluation of inflammatory response, however, it is necessary to further study the effective use of primary cells.

View full abstract

Hydrogen is one of the possible alternative energy sources to replace fossil fuels in the transportation sector. Hydrogen fuel cell vehicles (FCV) are expected to play an important role in the future. A composite storage tank to store compressed hydrogen is used for FCV. To prevent a tank from bursting in the case of a fire accident, a thermal pressure relief device (TPRD) is attached to the tank. In order to investigate the safety aspect of the TPRD system, a bonfire test was carried out. In this study, turbulent flame generated by the bonfire test was simulated with OpenFOAM which is an open source code of computational fluid dynamics. The appropriate flame is estimated with infinitely-fast chemistry assumption model and Large-eddy simulation. It is expected that the fluid-structure interaction with conjugate heat transfer can be applied to bonfire test simulation.

View full abstract

Positive matrix factorization (PMF) and Chemical Mass Balance (CMB) were demonstrated for synthetic datasets that suppose ambient organic aerosol mass spectra from two sources. Two different organic aerosol mass spectra scenarios using different sources were considered. The scenario assumed that similar time variations occurred between diesel exhaust particles as a primary organic aerosol (POA) and m-xylene-derived secondary organic aerosol (SOA). In this case, it was found that PMF separate out factors corresponding to POA and SOA, and the two sources made relatively uniform contributions to the synthetic time trend data. CMB represented similar contributions corresponding to POA and SOA in the scenario.

View full abstract