The Belle Silicon Vertex Detector

The silicon vertex detector of the Belle experiment has been built to provide the vertex information of $B$ meson decays at the KEKB accelerator. Performance during the initial data taking period and a brief description of the upgrade plan are also presented.Comment: To appear in the Proceedings of the 4th International Symposium on Development and Application of Semiconductor Tracking Detectors, March 22 - 25, 2000 Hiroshima, Japa

Water reuse and recycling in Japan — History, current situation, and future perspectives

Water reuse is an effective option all over the world for saving water resources, reducing environmental impacts, and reducing the costs and energy involved in water resource management. In Japan, non-potable water reuse has been implemented in several cities since the 1980s, mainly for urban applications such as toilet flushing, urban stream water augmentation, and landscape irrigation. However, utilization of reclaimed water is still limited in Japan due to the inadequate quality standards for reclaimed water and the high energy consumption of water reclamation facilities. From 2010 to 2015, a Core Research for Evolutional Science and Technology (CREST) project was carried out in Japan to develop energy-efficient water reclamation processes utilizing membrane technologies and ozonation processes. A comprehensive evaluation of the process performances and the economic feasibility showed that the UF ​+ ​UV (ultrafiltration ​+ ​ultraviolet radiation) process provided removal of viruses to a level adequate for water reuse for agricultural purposes at low cost. Based on the results from the CREST project, a demonstration plant incorporating the UF ​+ ​UV process was constructed at the Itoman wastewater treatment plant in Okinawa to evaluate performance in terms of virus removal and to implement agricultural water reuse. Other innovative technologies are also under development in Japan to reduce the cost and energy involved in water reclamation. This paper introduces the history, current situation, and future perspectives of water reclamation and reuse in Japan

Partially-disordered photonic-crystal thin films for enhanced and robust photovoltaics

We present a general framework for the design of thin-film photovoltaics based on a partially-disordered photonic crystal that has both enhanced absorption for light trapping and reduced sensitivity to the angle and polarization of incident radiation. The absorption characteristics of different lattice structures are investigated as an initial periodic structure is gradually perturbed. We find that an optimal amount of disorder controllably introduced into a multi-lattice photonic crystal causes the characteristic narrow-band, resonant peaks to be broadened resulting in a device with enhanced and robust performance ideal for typical operating conditions of photovoltaic applications.Comment: 5 pages, 4 figure

SPADExp: A photoemission angular distribution simulator directly linked to first-principles calculations

We develop a software package SPADExp (simulator of photoemission angular distribution for experiments) to calculate the photoemission angular distribution (PAD), which is the momentum dependence of spectrum intensity in angle-resolved photoemission spectroscopy (ARPES). The software can directly load the output of the first-principles software package OpenMX, so users do not need to construct tight-binding models as previous studies did for PAD calculations. As a result, we can calculate the PADs of large systems such as quasicrystals and slab systems. We calculate the PADs of sublattice systems (graphene and graphite) to reproduce characteristic intensity distributions, which ARPES has experimentally observed. After that, we investigate twisted bilayer graphene, a quasicrystal showing 12-fold rotational symmetric spectra in ARPES, and the surface states of the topological insulator $\mathrm{Bi}_2\mathrm{Se}_3$. Our calculations show good agreement with previous ARPES measurements, showing the correctness of our calculation software and further potential to investigate the photoemission spectra of novel quantum materials.Comment: 19 pages, 5 figures, Software has been developed in https://github.com/Hiroaki-Tanaka-0606/SPADEx