Ibaraki National College of Technology

Abstract In high-intensity proton accelerators, it is crucial to identify and reduce sources of beam loss, which requires rapid measurement of the beam distribution in both position and velocity space. In this study, we have developed a completely new non-destructive bunch shape monitor that measures the longitudinal distribution of the H− (negative hydrogen) beam by using the repetitive laser pulses and measuring the amount of the photo-detached beam. A proof-of-principle experiment successfully measured the longitudinal beam profile of the 3 MeV H− beam at the test accelerator of J-PARC. This paper describes the concept of the monitor, presents the measurement results, and discusses its applicability to the future beam diagnostics.

Abstract Neutrinos from supernovae, especially those emitted during the late phase of core collapse, are essential for understanding the final stages of massive star evolution. We have been dedicated to developing methods for the analysis of neutrinos emitted during the late phase and observed at Super-Kamiokande (SK). Our previous studies have successfully demonstrated the potential of various analysis methods in extracting essential physical properties; however, the lack of background consideration has limited their practical application. In this study, we address this issue by incorporating a realistic treatment of the experimental signal and background events with the on-going SK experiment. We therefore optimize our analysis framework to reflect realistic observational conditions, including both signal and background events. Using this framework we study several long-time supernova models, simulating the late phase neutrino observation in SK and focusing in particular on the identification of the last observed event. We discuss the possibility of model discrimination methods using timing information from this last observed event.

Catalytic cyclopropanation reactions are demonstrated in the Research Article (e202403485) by Koji Oohora, Takashi Hayashi et al. using myoglobins reconstituted with artificial cofactors with various redox potentials. The cover image illustrates this catalysis by showing two types of protein-based trucks carrying rice ears (starting material) to produce rice sacks (product). The elevation profiles of the routes represent the differences in the reaction energy at the active center for each cofactor. Representative artificial cofactors are shown as stick-and-ball models. Catalytic cyclopropanation reactions are demonstrated in the Research Article (e202403485) by Koji Oohora, Takashi Hayashi et al. using myoglobins reconstituted with artificial cofactors with various redox potentials. The cover image illustrates this catalysis by showing two types of protein-based trucks carrying rice ears (starting material) to produce rice sacks (product). The elevation profiles of the routes represent the differences in the reaction energy at the active center for each cofactor. Representative artificial cofactors are shown as stick-and-ball models. Supercapacitors Electrocatalysis Plastic Upcycling Cluster Compounds

The Japanese sardine (Sardinops sagax melanostictus) is a small pelagic fish found in the Sea of Japan, the marginal sea of the western North Pacific. It is an important species for regional fisheries, but their dispersal and migration patterns during early life stages remain unclear. In this study, we analyzed the stable oxygen isotope ratios of otoliths of young-of-the-year (age 0) Japanese sardines collected from the northern offshore and southern coastal areas of the Sea of Japan in 2015 and 2016. The ontogenetic shifts of the geographic distribution were estimated by comparing the profiles of life-long isotope ratios and temporally varying isoscape, which was calculated using the temperature and salinity fields produced by an ocean data assimilation model. Individuals that were collected in the northern and southern areas hatched and stayed in the southern areas (west offshore of Kyushu) until late June, and thereafter, they can be distinguished into two groups: one that migrated northward at shallow layer and one that stayed around the southern area in the deep layer. A comparison of somatic growth trajectories of the two groups, which was reconstructed based on otolith microstructure analysis, suggested that individuals that migrated northward had significantly larger body lengths in late June than those that stayed in the southern area. These results indicate that young-of-the-year Japanese sardines that hatched in the southern area may have been forced to choose one of two strategies to avoid extremely high water temperatures within seasonal and geographical limits. These include migrating northward or moving to deeper layers. Our results indicate that the environmental variabilities in the southern area could critically impact sardine population dynamics in the Sea of Japan.

The widely used DC-DC converters are inductor-based DC-DC converters and inductors along with combustion. The use of inductors can lead to large power losses, as well as heavy components in real terms. The proposed converter warning array aims to increase the voltage with a large increase ratio through a switching configuration process. This switching method is very simple and uses two pulses that are opposite each other so that the array converter can work optimally, whose function is to adjust the arrangement in a parallel arrangement to a series arrangement. The advantage of using a device is that it makes DC-based DC conversion lightweight and easy to implement. Tests have been carried out on 5 hanger arrays with a power of 80 W and 65 W, and the data from the test results show that the voltage increase ratio reaches 81.5 % or 4.08 times the input voltage, which indicates that the array converter warning is able to increase the input voltage according to the number of the arrays.