We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.

In this study, direct numerical simulation of the flow around a rotating sphere at high Mach and low Reynolds numbers is conducted to investigate the effects of rotation rate and Mach number upon aerodynamic force coefficients and wake structures. The simulation is carried out by solving the three-dimensional compressible Navier–Stokes equations. A free-stream Reynolds number (based on the free-stream velocity, density and viscosity coefficient and the diameter of the sphere) is set to be between 100 and 300, the free-stream Mach number is set to be between 0.2 and 2.0, and the dimensionless rotation rate defined by the ratio of the free-stream and surface velocities above the equator is set between 0.0 and 1.0. Thus, we have clarified the following points: (1) as free-stream Mach number increased, the increment of the lift coefficient due to rotation was reduced; (2) under subsonic conditions, the drag coefficient increased with increase of the rotation rate, whereas under supersonic conditions, the increment of the drag coefficient was reduced with increasing Mach number; and (3) the mode of the wake structure becomes low-Reynolds-number-like as the Mach number is increased.

Heat-assisted magnetic recording (HAMR) is being developed as the next-generation magnetic recording technology. High anisotropy granular media such as FePt-C have been demonstrated as HAMR media for ∼2 Tbpsi (terabits per in2) recording density. In order for this technology to reach its full potential of 4–5 Tbpsi, more progress and innovations are needed for the key requirements for HAMR media, including microstructure, design, magnetic distribution, and thermal design. Beyond granular media, heated-dot magnetic recording (HDMR) is planned to extend areal density toward 10 Tbpsi. HDMR combines similar advanced recording layer materials with advanced patterning techniques to fabricate <10-nm rectangular dot media.

A newly developed catadioptric optical system and a modified york-type equatorial mounting were designed and constructed. This telescope will be installed at Saipan Island for observing Comet Halley in Feb.-Apr. 1986.

We present here the fundamental idea of the conversion method between old and new reference frameworks. Some practical applications are made for the optical observations for Tokyo PZT. The method can be also applied to the conversion of radio sources where we have met a great difficulty in performing the conversion because of no citation of observation epochs in general. We discuss their necessity in order to establish a concrete compilation of the position of the radio sources.

Experimental and theoretical studies on the growth rate of an icicle were carried out as a function of temperature, water-supply rate and wind speed; the relative humidity was also taken into account. The length of an icicle increases by the downward growth of thin dendritic crystals into the supercooled pendant water drop at the tip, and thus the growth is in the crystallographic a-axis direction. The diameter, on the other hand, increases by the freezing of a water film flowing down along the icicle wall. The ratio of measured length-and diameter-growth rates was large, namely 8–32.

Both growth rates increased with decreasing temperature and increasing wind speed. The increase in water-supply rate led to the decrease in the length-growth rate but no significant change in the diameter-growth rate. These results could be well described by a numerical model of icicle growth which takes account of the dendritic growth at the tip and the wall and the effective heat transfer within the turbulent boundary layer around the icicle. A formation mechanism of ribs and hollows is discussed in relation to the flowing and freezing process of water on an icicle wall.

In order to investigate the distinguishability about the progenitors of FeCCSNe and ECSNe, we calculate the luminosities and spectra of their pre-SN neutrinos and estimate the number of events at neutrino detectors.

RXJ 13434+0001 is a rare example of radio-quiet type-2 quasars at high redshift. It was discovered through deep ROSAT observations and identified with a galaxy with a strong but narrow Lyα emission line at z = 2.35. In order to constrain the hard-X-ray properties we observed RXJ 13434+0001 with ASCA. The main purpose is to study the origin of the X-ray emission observed with ROSAT. If it is a scattered component from a strongly absorbed AGN, we could see it much brighter in the hard X-ray band.

We are constructing the ASCA GIS source catalog from the ASCA public archive, mainly for extra-galactic sky. The large field of view and the low-background characteristics of the GIS make it suitable for a search for serendipitous sources in a wide energy band of 0.7-10 keV. Sources to be detected by the project will provide valuable information on the log N-log S relation over the entire sensitivity band, which has never been available before. About this project, also refer to Ishisaki et al. (1995), Ueda et al. (1997) and Takahashi et al. (1997). There is the SIS source catalog project, too (Gotthelf et al., 1996). These catalogs are going to appear on the WEB.

To reveal the origin of the cosmic X-ray background (CXB) in the hard band, we are now conducting a wide (~ 7 deg2) and deep (~ 1 × 10−13 erg sec−1 cm−2 in the 2-10 keV band) survey with the ASCA (the ASCA Large Sky Survey, hereafter LSS). We have detected 83 sources above 4 sigma level in the 0.7-10 keV band with the GIS and resolved ~30% of the CXB in the 2-10 keV band into discrete sources (Ueda 1996). AGNs (type 1 and type 2) and clusters of galaxies are expected to be major contributers to these X-ray sources.

ASCA DSS was intended to carry out unbiased surveys in wide energy range of 0.5-10 keV. The strategy of this project is to survey small sky region with extremely high sensitivity reaching to the source confusion limit of ASCA XRT, in contrast to the Large Sky Survey project (Ueda 1996) which covers much larger sky area with relatively shallow exposure.

The origin of the Cosmic X-ray Background (CXB) radiation has been investigated extensively by soft X-ray deep survey imaging observations with Einstein and ROSAT. In contrast, the lack of telescopes capable of detecting hard X-rays has prevented us from extensive study of the nature of the CXB in the energy range above 2 keV before ASCA.

The observation of 8B solar Neutrinos in the Kamiokande-II detector is presented. Based on 450 days of data in the time period of January 1987 through May 1988, the measured flux obtained with Ee ≥ 9.3 MeV was 0.46 ± 0.13 (stat) ± 0.08 (sys) of the value predicted by the standard solar model. The detector and analysis methods were improved since June 1988 and the background level has been decreased by a factor of about three since then.

Knowledge of the groundwater age is indispensable for understanding groundwater flow in crystalline rocks. The present study is the first to discuss the radiocarbon ages of groundwater in Abukuma granite, Fukushima Prefecture, northeast Japan. The vertical profiles of 14C dates and δ13C are obtained from 3 boreholes (depths of 140, 230, and 306 m). Chemical and carbon isotopic compositions suggest that dead-carbon contamination of groundwater occurred during groundwater storage in the fractures. 14C concentration was corrected by using isotopic mass balance in which dead-carbon contamination of the groundwater was considered. The 14C dates ranged from modern to ≃16 ka. The relationship between tritium and 14C data in 1 borehole suggests the simultaneous inflow of shallow groundwater to deeper levels occur for the depths between 60 and 100 m. The vertical profiles of 14C dates indicate a relatively constant age of 10–16 ka for groundwater deeper than 100 m, which may have been influenced by rapid sea-level changes after the glacial period.

Heptavalent pneumococcal conjugate vaccine (PCV7) was introduced to Japan in 2010. We investigated the impact of PCV7 on childhood community-acquired pneumonia (CAP) and pneumococcal pneumonia (PP). Children aged <5 years living in Chiba city, Japan, who were admitted to hospitals were enrolled to estimate the incidence of CAP based on the mid-year population. PP was determined by the presence of Streptococcus pneumoniae in cultured blood and/or sputum samples of CAP patients. The incidence of CAP and S. pneumoniae isolated from PP patients was compared before (April 2008–March 2009) and after (April 2012–March 2013) the introduction of PCV7 immunization. The annual incidence of CAP was reduced [incidence rate ratio 0·81, 95% confidence interval (CI) 0·73–0·90]. When comparing post-vaccine with pre-vaccine periods, the odds ratio for PP incidence was 0·60 (95% CI 0·39–0·93, P = 0·024). PCV7-covered serotypes markedly decreased (66·6% in pre-vaccine vs. 15·6% in post-vaccine, P < 0·01), and serotypes 6C, 15A, 15C and 19A increased. Multidrug-resistant international clones in the pre-vaccine period (Spain6B-2/ST90, Taiwan19F-14/ST236) decreased, while Sweden15A-25/ST63 was the dominant clone in the post-vaccine period. A significant reduction in the incidence of both CAP hospitalizations and culture-confirmed PP of vaccine serotypes was observed at 2 years after PCV7 vaccination.

Contributions of electronic (or ligand) and geometric (or ensemble) effects on the AuM bimetallic nano-catalyst were elucidated by using a simple aerobic oxidation of 1-phenylethanol to acetophenone on the basis of difference in the ionization energy values (Ei) between Au and M elements. The poly(N-vinylpyrrolidone) (PVP)-protected Au60M40 bimetallic NPs (M = Ag, Cu, Pd, Pt and Ir) were prepared with a polyol reduction method, and stabilized onto the solid base hydrotalcite support affording the Au60M40-PVP/HT catalysts. The yields for acetophenone were observed as the following order; Au60Pd40-PVP/HT (>99%) >> Au60Ag40-PVP/HT (17.4%) > Au60Cu40-PVP/HT (13.8%) > Au60Pt40-PVP/HT (7.1%) > Au60Ir40-PVP/HT (5.5%), at 343 K for 6 h. Differences in the Ei between Au and M (EiAu-EiM) indicted that the yields over the Ag, Cu, Pt, and Ir incorporated Au catalysts were well-understood on the ligand effects theory, though geometric factors such as differences in nanostructure around Au atom in Au60M40 NPs on HT should be further considered as other contributed factors. The significant activity on Au60Pd40-PVP/HT was studied in terms of the electron density of Pd atoms. It was observed that the Pd 4d density was varied by the amount of Au loading. According to these observations combined with our previous studies, we suggest that the advantages in AuPd bimetallic catalyst are not only in the ligand effect serving negatively-charged Au but also the ensemble effect of neighbor Pd, and they synergistically contribute to the novel activity for aerobic alcohol oxidation over AuPd catalyst.