Publications by authors named "M Shiraiwa"

Article Synopsis
  • * This research uses a specific spin trap (BMPO) combined with mass spectrometry and liquid chromatography to understand how free radicals behave in these analytical techniques.
  • * The study introduces a new mechanism for how certain ions (oxidized and reduced BMPO adducts) form and provides methods to differentiate between various ion types, enhancing our knowledge of radical chemistry.
View Article and Find Full Text PDF

Multiphase interactions and chemical reactions at indoor surfaces are of particular importance due to their impact on air quality in indoor environments with high surface to volume ratios. Kinetic multilayer models are a powerful tool to simulate various gas-surface interactions including partitioning, diffusion and multiphase chemistry of indoor compounds by treating mass transport and chemical reactions in a number of model layers in the gas and condensed phases with a flux-based approach. We have developed a series of kinetic multilayer models that have been applied to describe multiphase chemistry and interactions indoors.

View Article and Find Full Text PDF

Understanding growth mechanisms for particles in air is fundamental to developing a predictive capability for their impacts on human health, visibility, and climate. In the case of highly viscous semi-solid or solid particles, the likelihood of impinging gases being taken up to grow the particle will be influenced by the initial uptake coefficient and by the residence time of the adsorbed gas on the surface. Here, a new approach that combines Knudsen cell capabilities for gas uptake measurements with temperature programmed desorption (TPD) for binding energy measurements of gases is described.

View Article and Find Full Text PDF

Uptake coefficients of butylamine (BA) on solid succinic (SA) and glutaric acids (GA) from 298 to 177 K were measured using a newly combined Knudsen cell temperature-programmed desorption apparatus. The uptake coefficients on SA increase monotonically from (1.9 ± 0.

View Article and Find Full Text PDF
Article Synopsis
  • EPFRs are significant pollutants linked to air quality issues, especially in Fairbanks, Alaska, where they were studied during winter 2022.
  • High concentrations of EPFRs were found during temperature inversions and were associated with markers of incomplete combustion, including carbon monoxide and elemental carbon.
  • Exposure to EPFR levels can be comparable to smoking 0.4-1 cigarette daily, and they may induce oxidative stress in the respiratory system based on their strong correlation with hydroxyl radical formation.
View Article and Find Full Text PDF