Narrow Results

To confirm the quantitative accuracy of PIXE analysis instruments, we measured NIST SRM air particles on filter media using different types of PIXE analysis instrument: in-air micro-PIXE, in-air PIXE, in-vacuum PIXE, and in-vacuum micro-PIXE. Then, we compared the measured values with certified values and reference values of NIST SRM. We found that the quantitative values of the NIST SRM filter media measured with each PIXE instrument were within 90% to 110% of the NIST-certified and reference values for most elements. In particular, the quantitative values of major elements ranged from 90% to 110% for the in-air PIXE (Kyoto University), the in-vacuum PIXE, and the in-vacuum micro-PIXE at Tohoku University, and the relative errors are also small. These results will aid in determining the quantitative values of atmospheric particles on filter samples.

The present study aimed to evaluate the relationship between elemental changes in erythrocytes and hepatogenous anemia. Five chronic hepatitis C, five liver cirrhosis (HCV positive) and three healthy controls were enrolled in this study.

Using in-air micro-PIXE, we determined that K rods formed small nodule and Cl rods distributed diffusely in all over erythrocytes, resulting in disappearance of the donut-like pattern of erythrocytes. These findings may reect the alternation of ery- throcyte membrane structures. Fe dots were divided into two to four compartments in erythrocytes of control group, and the similar distribution of Fe rods was shown in those of chronic hepatitis and liver cirrhosis. Na concentrations analyzed by in-vacuum PIXE were significantly higher in liver cirrhosis than in chronic hepatitis and control, possibly because of the disturbance of Na–K pump. Present study suggests that the alternation of erythrocyte membrane and Na–K pump failure may participate in hepatogenous anemia accompanied with liver cirrhosis.

To characterize the chemical composition of aircraft exhaust particles, we developed a treatment method of jet fuel for an elemental analysis by an in-vacuum PIXE system. Eleven elements (Si, S, Cl, K, Ca, Cr, Fe, Ni, Cu, Zn, and Pb) were identified from each sample. The concentrations of S from five JET A-1 fuel samples collected on different days ranged from 30.4 to 440 wt.-ppm. The concentration level of S agreed well with the measurement results obtained by an in-air PIXE analysis, which we have previously performed to determine the major content elements and their concentration levels. Nine elements out of the identified 11 elements (Si, Cl, K, Ca, Cr, Ni, Cu, Zn, and Pb), which were not detected by the in-air PIXE analysis, were detected in all the JET A-1 fuel samples measured. Among these elements, Si, Ni, Cu, Zn, and Pb were found to be the major components. It is suggested that particles emitted from aircraft jet engines, which are generally in the size range smaller than 100 nm (ultrafine particles: UFPs), may contain Si, Ni, Cu, Zn, and Pb. These findings provide useful insights into the source apportionment of UFPs in and around airports.

To comprehend the elemental characterization of the particles emitted from an aircraft, we performed element analysis using in-vacuum PIXE for particles emitted from the carbon disc brakes and tires in addition to the exhaust particles produced by the jet engine. As for the elemental characteristics of aircraft source particulate matter, engine reversers mainly consisted of Al, Si, Ca, and Fe, and also included Ti, Cr, Mo, and W. The disc brakes mainly contained Si, Ca, and Fe, and also contained S, K, Ti, Cr, Ni, and Cu. In tires, Na, Al, Si, Ca, Fe, and Zn were mainly found, and S, K, and Ti were also detected. Thus, there was a difference in the trace elements found in the aircraft source particulate matter. These results aid in determining the component features of particles emitted from an aircraft.

In order to characterize particles emitted from aircraft, we analyzed the elemental composition information of particles collected from aircraft using positive matrix factorization (PMF). The factor profile and source contribution were deduced based on PMF analysis with five factors and 30 random starting points. Factor 1 contains particles derived from engine oil. Factor 2 contains particles originating from the friction between the runway surface and the tire. Factor 3 contains particles deposited on the runway surface, mainly composed of soil components. Factor 4 contains particles derived from the turbine blade. Factor 5 contains particles derived from plant combustion and particles scattered during landing. Engine reversers accounted for more than 85% of the element total value with factor 2, factor 4, and factor 5. The carbon disc brakes had different main factors depending on the sample. For the tire grooves, factor 2 and factor 3 accounted for the majority of the element total value. The PMF analysis revealed that the particles collected from aircraft contained elements with different modes of generation. In addition, it was found that particles derived from plant combustion, which are presumed to have little relevance to particles emitted from aircraft, were included in the particles collected from the engine reverser, carbon disc brakes, and tire grooves.