No abstract

Since diesel soot particles (black carbon, BC) is a very fine particle of about 10 to 50 nm, there is a possibility that it invades deep into human lungs. In order to evaluate the impact of BC on human health, it is necessary to observe the detailed structure of BC along with toxicology. Focused ion beam time-of-flight secondary ion mass spectrometer (FIB-TOF-SIMS) developed by the authors, has a high spatial resolution and low detection limit, and the components imaging of individual particle can be analyzed with many kinds of aerosol. However, since BC is very small, the detailed structure of particles cannot be observed directly with the FIB-TOF-SIMS. In this study, in order to evaluate the structure of BC, we combined a new aerosol dialysis method and the FIB-TOF-SIMS. In this method, even if the lateral resolution is insufficient, the structure of BC can be visualized with separating the particles and surface adhering components, respectively.

Changes in the internal state of a high-power capacitor during progressive charge–discharge cycling were measured non-destructively using high-energy synchrotron X-ray Compton scattering. The stacked structure of a laminated capacitor was clearly indicated by a Compton scattered X-ray intensity analysis and a line shape (S-parameter) analysis of a Compton scattered X-ray energy spectrum. Moreover, apparent differences in the progress of charge and discharge cycles were observed in the correlation between Compton scattered X-ray intensities and S-parameters obtained from the center and edge positions within the in-plane of the electrode. This difference in the correlation was obtained from the shifting of the stacked structure at the edge position, induced by the drift of the electrolyte material within the capacitor cells.

For the analysis of aerosol, the bulk analysis method of collected particles on a filter is widely used. In the bulk analysis, the information with high accuracy as the averaged value of collected particles can be obtained, but the information of individual particle is disappeared. Some surface analysis techniques such as SIMS and SEM-EDX have also been employed for individual particle analysis. Since the individual analysis for all the collected particles is not realistic in terms of analytical time, statistically reliable data cannot be obtained. Therefore, it is difficult to compare the data of individual particle analysis with bulk analysis data and discuss the abundance ratio of particles. In this study, aerosol was analyzed with a high resolution by means of FIB-TOF-SIMS developed by our group. From the results of the individual particle analysis, it was found that there is a good correlation between the aerosol type and shape of particles. But, these need much time and labor. Therefore, a method for classification particles from shape data was devised. Based on a shape to be provided from an SEM image, they are classified by means of cluster analysis.