No abstract

Laser-ablation atomic fluorescence (LAAF) spectroscopy has extremely high sensitivity in the analysis of trace elements. Using the ArF laser-ablation technique at a wavelength of 193 nm, removal of thin surface layer of the order of 1.1 nm/shot for the first 50 shots and 0.4 nm/shot after that is demonstrated for a solid glass sample. A constant fluorescence signal from Na atoms is obtained for each shot. There is a possibility of determining the depth distribution of an element with subnanometer resolution by applying LAAF spectroscopy.

This research aims to clarify the influence of driver visibility on crossing accidents. We investigated 1,101 accidents occurring at 621 intersections in the Hakata-ku Ward, Fukuoka City, from 2015 to 2017. We calculated the yearly accident rate at each intersection based on the accident data and evaluated driver visibility with surveyed intersection information. It was found that the accident rate was high when visibility was poor regardless of the number of lanes on the secondary road at locations where many accidents occurred, and the accident rate was high when the number of lanes on the secondary road was low throughout Hakata Ward. .

This paper shows the characteristics of crossing collision accident by accident party. As Fukuoka Prefecture has the third most accidents in Japan, we selected Hakata and Chuo Ward in Fukuoka city as the target of the investigation. We investigated 1,810 crossing collision accidents and 2,662 intersections' environmental factors such as traffic lights and intersection shape. In addition, we classified the accidents into car to car accidents and car to bicycle accidents according to the type of accident parties involved. Characteristics of car to car accidents tending to occur at crossroads and car to bicycle accidents occurring regardless of the traffic regulations have been clarified.