Maser polarization changes during a pulsation in the CSE of an AGB star are related in a complicated way to the magnetic field structure. 43 GHz SiO maser transitions are useful for polarization study because of their relatively simple Zeeman splitting structure and their location. This work uses 3D maser simulation to investigate the effect of the magnetic field on maser polarization with different directions. The results show that linear polarization depends on the magnetic direction while circular polarization is less significant. The EVPA changes through π/2 at an angle of around 50 degrees, approximately the Van Vleck angle. The EVPA rotation result from 3D maser simulation is consistent with results from 1D simulations, and may explain the 90 degree change of the EVPA within a single cloud in the observational cases of TX Cam and R Cas.

National Astronomical Research Institute of Thailand (Public Organization) initiated a national flagship project in 2017 for development of radio astronomy and geodesy in Thailand. In this project, a 40-m Thai National Radio Telescope (TNRT) and a 13-m VLBI Global Observing System (VGOS) radio telescope as its co-location are constructed in Chiang Mai. The 40-m TNRT is the largest telescope for radio astronomy in South-East Asia. Its flexible operation with a wide-coverage of observable frequencies 0.3-115 GHz will allow us to uniquely contribute to the time-domain astronomy as well as carry out unbiased surveys for a wide variety of science research fields, which were published in a white paper. Within the framework of collaboration with VLBI arrays in the world, TNRT will drastically improve the imaging quality and performances based on its unique geographical location, for both radio astronomy and geodetic VLBI studies in South-East Asia for the first time. On-going commissioning of TNRT particularly in the L-band system (1.0–1.8 GHz) is introduced as well as vision for establishment of forthcoming regional VLBI networks based on TNRT: Thai National VLBI Array and South-East Asian VLBI Network in collaboration with Indonesia, Malaysia, and Vietnam.

This study examines the relationship between paternal height or body mass index (BMI) and birth weight of their offspring in a Japanese general population. The sample included 33,448 pregnant Japanese women and used fixed data, including maternal, paternal and infant characteristics, from the Japan Environment and Children’s Study (JECS), an ongoing nationwide birth cohort study. Relationships between paternal height or BMI and infant birth weight [i.e., small for gestational age (SGA) and large for gestational age (LGA)] were examined using a multinomial logistic regression model. Since fetal programming may be a sex-specific process, male and female infants were analyzed separately. Multivariate analysis showed that the higher the paternal height, the higher the odds of LGA and the lower the odds of SGA in both male and female infants. The effects of paternal BMI on the odds of both SGA and LGA in male infants were similar to those of paternal height; however, paternal height had a stronger impact than BMI on the odds of male LGA. In addition, paternal BMI showed no association with the odds of SGA and only a weak association with the odds of LGA in female infants. This cohort study showed that paternal height was associated with birth weight of their offspring and had stronger effects than paternal BMI, suggesting that the impact of paternal height on infant birth weight could be explained by genetic factors. The sex-dependent effect of paternal BMI on infant birth weight may be due to epigenetic effects.

Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in glacier melt independently from model output. Here, we present a comprehensive database of Greenland glacier surface mass-balance observations from the ablation area of the ice sheet and local glaciers. The database spans the 123 a from 1892 to 2015, contains a total of ~3000 measurements from 46 sites, and is openly accessible through the PROMICE web portal (http://www.promice.dk). For each measurement we provide X, Y and Z coordinates, starting and ending dates as well as quality flags. We give sources for each entry and for all metadata. Two thirds of the data were collected from grey literature and unpublished archive documents. Roughly 60% of the measurements were performed by the Geological Survey of Denmark and Greenland (GEUS, previously GGU). The data cover all regions of Greenland except for the southernmost part of the east coast, but also emphasize the importance of long-term time series of which there are only two exceeding 20 a. We use the data to analyse uncertainties in point measurements of surface mass balance, as well as to estimate surface mass-balance profiles for most regions of Greenland.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

We present VLBI maps of the 6.7 GHz methanol maser emission in 32 sources obtained using the Japanese VLBI Network (JVN) and the East-Asian VLBI Network (EAVN). All of the observed sources provide new VLBI maps, and the spatial morphologies have been classified into five categories similar to the results obtained from European VLBI Network observations (Bartkiewicz et al. 2009). The 32 methanol sources are being monitored to measure the relative proper motions of the methanol maser spots.

NEWAGE is a direction-sensitive dark matter search experiment with a gaseous time-projection chamber. We improved the direction-sensitive dark matter limits by our underground measurement. In this paper, R&D activities sinse the first underground measurement are described.

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

We propose a parallel resistance model (PRM) in which total resistance (Rtotal) is given by the parallel connection of resistance of a filament (Rfila) and that of a film excluding the filament (Rexcl)—that is, 1/Rtotal = 1/Rfila + 1/Rexcl—to understand direct current (dc) electric properties of resistive random-access memory (ReRAM). To prove the validity of this model, the dependence of the resistance on temperature, R(T), and the relative standard deviation (RSD) of RHRS of Pt/NiO/Pt on the area of a top electrode, S, are investigated. It is clarified that both the R(T) and RSD depended on S, and all such dependencies can be explained by the PRM. The fact that Rtotal is decided by the magnitude relation between Rfila and Rexcl makes transport properties S-dependent and hinders the correct understanding of ReRAM. Smaller S is essential to observe the intrinsic transport properties of ReRAM filaments.

We report on the transformation behaviour of metastable defects labelled EM1 (Ec-0.29 eV), EM2 (Ec-0.41 eV) and EM3 (Ec-0.55 eV) which are induced in n-type silicon by hydrogen implantation. Hydrogen implantation was performed at 88 K with an energy of 90 keV to a dose of 2 × 1010 cm−2. After fabrication of Schottky diodes on the implanted surfaces, deep level transient spectroscopy measurements were made to monitor metastable behaviour of defects. All three metastable defects are regenerated with reverse-bias cooling and removed with zero-bias cooling. 10-min isochronal annealing reveals that EM1 is regenerated around 270 K and is removed around 220 K. The EM2 (EM3) regeneration temperature is around 270 K (270 K) and its removal temperature 220 K (260 K). Isothermal annealing treatments for EM1 show that its transformation follows first order kinetics for both regeneration and removal. An activation energy is 0.94 eV and a frequency factor 6 × 1014 s−1 for regeneration of EM1, and 0.73 eV and 3 × 1013 s−1 for its removal.

Coin-shaped multicrystalline Si1-xGex crystals were grown using a Brigdman method combined with die-casting growth. Si1-xGex alloy is known as a candidate material for producing Auger generation, which creates more than one electron/hole pair per absorbed photon. Since Si1-xGex alloy shows a complete series of solid solutions, precipitating crystals with a certain composition of silicon or germanium by conventional selective growth methods is burdensome. Using die-casting combined with Bridgman growth brought about Si1-xGex precipitation in a form completely different from that predicted by the Si-Ge phase diagram. By combining this growth with subsequent heat treatment of the precipitated Si1-xGex sample, Si1-xGex (x= 0.5 ± 3 %) could be obtained. Indirect band-gap energy was estimated by measuring room-temperature optical absorption coefficient of the grown samples.

Magnetic tunnel junctions of Co0.9Fe0.1/SrTiO3 (STO)/ La0.7Sr0.3MnO3 (LSMO) with a spin-valve structure having an antiferromagnetic MnIr layer have been fabricated by sputtering. Junction magnetoresistance (MR) behavior and its dependence on the bias voltage are examined for junctions with epitaxial STO barrier formed under different sputtering conditions. Spin dependent transport measurements show that these junctions exhibit spin-valve type MR loops with an inverse (positive) MR of the ratio of 14-22 % at 4.2 K. The inverse MR observed is asymmetric with respect to the bias voltage direction. Stoichiometric STO barrier, as characterized by Rutherford backscattering (RBS) analysis, is found to result in very large asymmetric bias dependence, while the junctions with nonstoichiometric STO barrier exhibit the symmetric bias dependence. Our results suggest that the nonstoichiometry of STO barrier modifies the electronic structures of electrode/barrier interfaces, and thereby reducing the asymmetry of bias voltage dependence of junction MR.

Optical properties of fully-strained wurtzite and zincblende InxGa1-xN/GaN multiple quantum well (MQW) structures were compared to discuss the origin of exciton localization. In contrast to the hexagonal InGaN MQWs, the photoluminescence (PL) peak energy of cubic InGaN MQWs showed a moderate blueshift with decreasing well thickness, L, and low-temperature PL decay time of the cubic MQWs did not depend strongly on L. The results imply that the wavefunction overlap in cubic InGaN MQWs was not reduced compared to the hexagonal ones, since they do not suffer from the electric field normal to the QW plane due either to spontaneous or piezoelectric polarization. Both MQWs exhibited a large and composition-dependent bandgap bowing, and time-resolved PL (TR-PL) signals showed a stretched-exponential decay even at room temperature. The exciton localization is considered to be an intrinsic property of InGaN.

Using a scanning Hall-sensor microscope with an active area 50pμm × 50μm, we succeeded in visualizing a breakdown of paramagnetic austenite-phase in 304 stainless steels induced by a plastic strain at room temperature, resulting from a transformation to ferromagnetic martensite-phase. Magnetic images of spontaneous magnetic fields on a surface of strained sample show the degree and the place (and/or the extent) of phase breakdown. Furthermore, the images nearly agree with the calculated results for the principal shear stress rather than the principal stress under plastic deformation, indicative of the driving force of this breakdown. The study should open a way for non-destructive evaluation of 304 stainless steels.

We carefully re-examine the evolution of small scale cosmological perturbations, motivated from the studies of cosmic structure formation in the high-z universe. Under the assumption of the hierarchical clustering scenario, the evolution of density fluctuations on very small scales is especially important for the early formation of the bound objects such as population III stars or primordial sub-galaxies.

Correlation between defect structures and light emission from Si-nanocrystal doped SiO2 films has been studied using electron spin resonance ( ESR ) and photoluminescence ( PL ) methods. The ESR analysis revealed the presence of three kinds of ESR centers in the film after annealing at above 900 °C in argon ( Ar ) atmosphere, i.e. Si dangling bond in amorphous Si cluster ( a-center: g=2.006 ), Si dangling bond at Si-nanocrystal/SiO2 interface ( Pb-center: g=2.003 ) and conduction electrons in Si-nanocrystal ( Pce-center: g=1.998 ). Moreover, visible light emission was observed in the annealed sample from the PL measurement. Both the PL intensity and the ESR signal intensity of the Pce-center were increased with an increase of annealing temperature. These results indicate that the Pce-center is strongly associated with the emission center.

The purpose of this study is to improve the reliability and reproducibility of our fabrication process for polycrystalline Cu(InGa)Se2 (CIGS) thin-film absorbers and to make a better absorber with higher efficiency. The current baseline process of selenization has been evaluated through the investigation of the formation chemistry of the device-quality CIGS thin-film absorbers with a graded band-gap structure. It has been verified that the current selenization process has been performed in a good balancing point with both Cu/III ratio and thickness of the precursor layer and the total amount of Se through H2Se gas incorporated from the surface during the selenization. A simplified model to explain the formation chemistry of the selenization in this study has been proposed.