It is thought that protoplanets formed in protoplanetary disks excite the orbital motion of the surrounding planetesimals, and the bow shocks caused by the highly excited planetesimals heat their icy component evaporating into gas. We have performed model calculations to study the evolution of molecular abundances of the evaporated icy component, which suggests sulfur-bearing molecules can be good tracers of icy planetesimal evaporation. Here we report the result of our ALMA observations of sulfur-bearing molecules towards protoplanetary disks. The lines were undetected but the obtained upper limits of the line fluxes and our model calculations give upper limits of the fractional abundances of x(H2S) < 10−11 and x(SO) < 10−10 in the outer disk. These results are consistent with the molecular abundances in comets in our Solar system.

A new target design is presented to model high-energy radiative accretion shocks in polars. In this paper, we present the experimental results obtained on the GEKKO XII laser facility for the POLAR project. The experimental results are compared with 2D FCI2 simulations to characterize the dynamics and the structure of plasma flow before and after the collision. The good agreement between simulations and experimental data confirms the formation of a reverse shock where cooling losses start modifying the post-shock region. With the multi-material structure of the target, a hydrodynamic collimation is exhibited and a radiative structure coupled with the reverse shock is highlighted in both experimental data and simulations. The flexibility of the laser energy produced on GEKKO XII allowed us to produce high-velocity flows and study new and interesting radiation hydrodynamic regimes between those obtained on the LULI2000 and Orion laser facilities.

In the present study, the crystallographic features of bcc/T1/T2 three-phase microstructure in a directionally solidified Mo–32.2Nb–19.5Si–4.7B (at.%) alloy have been examined by electron back-scattering diffraction (EBSD) analysis. The alloy was directionally solidified using an optical floating zone (OFZ) furnace in a flowing Ar gas atmosphere at a constant growth rate of 10 mm/hour. The microstructure of the directionally solidified alloy is characterized by an elongated T2 phase surrounded by inclusions of bcc and T1 phases with an interwoven morphology. The T2 grains are faceted on the (001) planes and elongated along the [110] direction. The T2 phase has an orientation relationship of (001)T2 // (011)bcc and [130]T2 // [2 ${\rm{\bar 1}}$ 1]bcc with the bcc phase, whereas any particular orientation relationships of T1 phase with bcc and T2 phases have not been found. These crystallographic features of bcc/T1/T2 three-phase microstructure suggest that the primary T2 phase crystallizes and grows along the [110] direction in liquid phase, followed by nucleation of the bcc phase on the interface between T2 and liquid phases, resulting in bcc/T1 two-phase eutectic reaction surrounding the elongated T2 phase.

New low aluminium high niobium TiAl alloys exhibit a nano scale modulated microstructure consisting of lamellae with a tweed substructure. These tweed like appearing lamellae are a modulated arrangement of at least two phases. One constituent of the crystallographic modulation in the lamellae is an orthorhombic phase, which is closely related to both the hexagonal α2-Ti3Al phase and the cubic B2 ordered βo-TiAl phase.

In this study the nature and formation of this orthorhombic phase has been investigated by high-energy X-ray diffraction.

Measurements have shown that the newly formed orthorhombic phase is structurally comparable to the O phase (Ti2AlNb). It forms in the temperature range of 550 °C to 670 °C from the α2 phase by small atomic displacements and chemical reordering. The in situ experiments yielded information about the thermal stability of the orthorhombic phase. After dissolving at temperatures above 700 °C the phase can be re-precipitated by annealing within the temperature range of formation.

The existence of Pt7Cu ordering phase (intermetallic compound) was investigated by ab initio calculations and high voltage electron microscopy (HVEM) focusing on irradiation-induced ordering. The Pt7Cu ordering phase (cF32, prototype Ca7Ge) was predicted at 0 K through density functional theory (DFT), and using cluster expansion (CE) method and grand canonical Monte Carlo (GCMC) simulation, the ordering temperature of fcc-based Pt7Cu ordering phase was estimated to be above room temperature. The formation of Pt7Cu ordering phase was confirmed by a short-time irradiation for 3.6×103 s at 600 K. MeV electron irradiation can reduce drastically the annealing time for the ordering in the Pt-Cu alloy system, indicating that the combination of the prediction by ab initio calculations and HVEM can offer the unique opportunity to investigate the existence of ordering phase in alloys.

Intermetallic titanium aluminides solidifying via the disordered β-phase are of great interest for several high-temperature applications in automotive and aircraft industries. In this paper the thermocyclic oxidation behavior of three β-solidifying γ-TiAl-based alloys at 800°C and 900°C in air, with and without fluorine treatment, is reported for the first time. The behavior of the well-known TNM alloy (Ti-43.5Al-4Nb-1Mo-0.1B, in at.%) is compared with that of two Nb-free model alloys which contain different amounts of Mo (Ti-44Al-3Mo and Ti-44Al-7Mo, in at.%). During thermocyclic high-temperature exposure in air a mixed oxide scale develops on all three untreated alloys. Small additions of fluorine in the subsurface region of the alloys change the oxidation mechanism from mixed oxide scale formation to alumina at both temperatures. The oxidation resistance of the fluorine treated samples was significantly improved compared to the untreated samples.

The electronic properties of the interface between Rh clusters and CeO2 (111), (110) and (100) surfaces were studied using an isothermal-isobaric (NPT) ensemble at 773 K and 101.343 kPa using the tight binding-quantum chemical molecular dynamics (TB-QCMD) method. The amount of electronic exchange by interaction at the interface between the supported Rh55 clusters and each CeO2 surface was investigated quantitatively. A comparison of the mean square displacement (MSD) showed that the topmost oxygens on the Rh-supporting CeO2 surface exhibited higher mobility than those of the bare CeO2 surface. Although the mobility of the topmost oxygens on the bare CeO2 surface was in the order (100) > (110) > (111), this sequence was altered by the presence of Rh, so that the oxygen mobility for the more open (110) surface was the largest. The amount of electron exchange that occurred between Rh and the CeO2 (110) surface was also larger than for the (111) or (100) surface. The Ce 4f orbitals on the CeO2 (110) surface exhibited the strongest mixing with Rh 4d orbitals, which simultaneously caused restructuring and instability of the topmost Ce-O bonds. This enhancement of oxygen migration in the presence of Rh was occurred together with an increase in the number of oxygen vacancies on the ceria surface. This was because the topmost oxygens was shifted to have a stronger affinity with Rh and thus formed stronger bonds with Rh than with Ce.

In the current research, we have utilized sol-gel electrophoresis technique to grow PbTiO3 nanotube arrays in porous anodic alumina template channels. By using this method high quality and more condense nanotubes are obtained compared with other usual sol-gel methods. Also, the effect of the anodizing parameters on the diameter of the template pores, and effect of electrophoresis voltage on wall thickness were investigated.

Ensuring microstructural stability under technical relevant conditions is a determining criterion for the development of innovative high-temperature materials. In this work, the influ-ence of C and Si on the microstructural stability during creep exposure was investigated for a β-solidifying γ-TiAl based alloy with a nominal composition of Ti-43.5Al-4Nb-1Mo-0.1B (in at.%), named TNM. With a two-step heat treatment a microstructure consisting of fine lamellar α2/γ-colonies, surrounded by βo-phase and areas of discontinuous precipitation, starting from the boundaries of the lamellar colonies, was adjusted. Creep tests were carried out to examine the potential of C and Si to prevent microstructural instability during creep and hence improving the creep properties. At 815 °C the discontinuous precipitation process of the TNM alloy continues during ensuing creep testing leading to a reduced creep resistance. In comparison, the minimum creep rate of the TNM-0.3C-0.3Si alloy was significantly decreased caused by the lower βo-phase content and average lamellar spacing within the α2/γ-colonies, the precipitation of p-Ti3AlC carbides and the retarded kinetics of discontinuous precipitation.

Pentacene-based ferroelectric gate transistors with croconic acid (CrA) thin film was fabricated for the first time. The memory window (MW) of 1.9 V was obtained from the capacitance-voltage (C-V) characteristics of Al/CrA(50 nm)/SiO2/Si(100) metal-ferroelectric-insulator-semiconductor (MFIS) diode, where the deposition temperature of CrA was room temperature (RT). Butterfly type C-V characteristics was observed for Al/CrA(50 nm)/Al/SiO2/ Si(100) metal-ferroelectric-metal (MFM) diode. Furthermore, a pentacene-based p-type organic field-effect transistor (OFET) with CrA gate insulator was fabricated, and clockwise hysteresis loop was observed in ID-VG characteristic, which is attributed to the ferroelectric properties of CrA gate insulator.

In this paper, we explore the interfacial effects appearing in highly strained La0.7Ca0.3MnO3 (LCMO) ultra-thin films (10-12nm) grown on BaTiO3 (BTO) ferroelectric substrates. The strong tendency to phase separation of this optimally doped manganite contributes to the exotic phenomena observed in magnetism and transport experiments: the so-called Matteucci magnetic loops, magnetic granularity and a second metal insulator transition are observed between 50K and the LCMO Curie temperature, 180K. All these properties define the multiferroic character of these heterostructures, which in LCMO//BTO system is strongly linked to magnetoelastic coupling.

Epidemiological studies suggested that n-6 fatty acids, especially linoleic acid (LA), have beneficial effects on CHD, whereas some in vitro studies have suggested that n-6 fatty acids, specifically arachidonic acid (AA), may have harmful effects. We examined the association of serum n-6 fatty acids with plasminogen activator inhibitor-1 (PAI-1). A population-based cross-sectional study recruited 926 randomly selected men aged 40–49 years without CVD during 2002–2006 (310 Caucasian, 313 Japanese and 303 Japanese-American men). Plasma PAI-1 was analysed in free form, both active and latent. Serum fatty acids were measured with gas-capillary liquid chromatography. To examine the association between total n-6 fatty acids (including LA and AA) and PAI-1, multivariate regression models were used. After adjusting for confounders, total n-6 fatty acids, LA and AA, were inversely and significantly associated with PAI-1 levels. These associations were consistent across three populations. Among 915 middle-aged men, serum n-6 fatty acids had significant inverse associations with PAI-1.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

We present the results of the Nobeyama Radio Observatory (NRO) M 33 All Disk (30′ × 30′, or 7.3 kpc  ×  7.3 kpc) Survey of Giant Molecular Clouds (NRO MAGiC) based on 12CO(J = 1–0) observations using the NRO 45-m telescope and 12CO(J = 3–2) observations using the ASTE 10-m telescope. The spatial resolution of the resultant 12CO(J = 1–0) map is 193, corresponding to 81 pc, which is sufficient to identify each Giant Molecular Cloud (GMC) in the disk. We found clumpy structures with a typical spatial scale of  ~100 pc, corresponding to GMCs, and no diffuse, smoothly distributed component of molecular gas at this sensitivity.

We obtained a map of the molecular fraction, fmol = ΣH2/(ΣHi + ΣH2), at a 100-pc resolution. This is the first fmol map covering an entire galaxy with a GMC-scale resolution. The correlation between fmol and gas surface density shows two distinct sequences. The presence of two correlation sequences can be explained by differences in metallicity, i.e., higher (~2-fold) metallicity in the central region (r <  1.5 kpc) than in the outer parts. Alternatively, differences in scale height can also account for the two sequences, i.e., increased scale height toward the outer disk.

We have conducted all disk imaging of M33 in 12CO(1-0) using the 45-m telescope at Nobeyama Radio Observatory. We present preliminary results of this project. The spatial resolution of ~ 80 pc is comparable to the size of GMCs. The identified GMCs show wide variety in star forming activity. The variety can be regarded as the difference of their evolutionary stage. We found that Kennicutt-Schmidt law breaks in GMC scale (~ 80 pc), although it is still valid in 1 kpc scale. The correlation between molecular gas fraction, fmol = Σ(H2)/Σ(HI+H2) and gas surface density shows two distinct sequences and shows that fmol tends to be higher near the center. We also made partial mapping 12CO(3-2) with ASTE telescope. These data show that the variation of physical properties of molecular gas are correlated with the GMC evolution and mass. That is, GMCs with more active star formation and more mass tend to have higher fraction of dense gas.

We have mapped the nearby face-on spiral galaxy M 33 in the 1.1 mm dust continuum using AzTEC on Atacama Submillimeter Telescope Experiment (ASTE). The preliminary results are presented here. The observed dust has a characteristic temperature of ~ 21 K in the central kpc, radially declining down to ~ 13 K at the edge of the star forming disk. We compare the dust temperatures with KS band flux and star formation tracers. Our results imply that cold dust heating may be driven by long-lived stars even nearby star forming regions.

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

Since electromagnetic (EM) noise resulting from an arc discharge disturbs other electric devices, parameters on electromagnetic compatibility, as well as lifetime and reliability, are important properties for electrical contacts. To clarify the characteristics and the mechanism of the generation of the EM noise, the current noise up to GHz band frequency generated by slowly breaking contacts with external direct current (dc) magnetic field, up to 40 mT, was investigated experimentally using Ag and AgSnO2 material. To reveal the characteristics as pure clean surface contact operation, the arc only at the operation of the first contact break was measured. Firstly, the effect of the external dc magnetic field on the duration and voltage fluctuation of the breaking arc of AgSnO2 material, which has relatively longer arc duration, was quantified. The experimental results on AgSnO2 material newly revealed that although applying external dc magnetic field is effective in reduction of duration of gaseous phase in arc discharge, higher variation of contact voltage in the gaseous phase which results in high frequency noise is caused. Secondly, the effect of the external dc magnetic field on the breaking arc of Ag was measured. It was found that larger current noise arises, when the contact voltage is rapidly varied at the arc discharge. There are two kinds of rapid changes, which cause high-frequency EMC problem, in the voltage waveform. One is at extinction of arc discharge. Other kind is short-duration arc (short-arc) before the ignition of the continuous metallic arc. Especially, we focused on the characteristics of the short-arc at the initial of the opening of the contact for clarifying the high frequency EMC problem. It was demonstrated that the spectrum of current noise in the case of “B = 30 mT” is smaller than that in the case of “B = 0 mT”. In addition, duration and fluctuation of short-arc is suppressed by the dc magnetic field. These results are basic and useful finding to know not only the noise generation in the contact-breaking phenomena but also the material dependency for EMC problems.

Wolbachia bacteria are among the most common endosymbionts in insects. In Wolbachia research, the Wolbachia surface protein (wsp) gene has been used as a phylogenetic tool, but relationships inferred by single-locus analysis can be unreliable because of the extensive genome recombination among Wolbachia strains. Therefore, a multilocus sequence typing (MLST) method for Wolbachia, which relies upon a set of five conserved genes, is recommended. In this study, we examined whether the alnus ambrosia beetle, Xylosandrus germanus (Blandford), is infected with Wolbachia using wsp and MLST genes. Wolbachia was detected from all tested specimens of X. germanus (n=120) by wsp amplification. Five distinct sequences (i.e. five alleles) for wsp were found, and labeled as wXge1–5. MLST analysis and molecular phylogeny of concatenated sequences of MLST genes identified wXge3 and wXge5 as closely-related strains. The detection rate of wXge4 and wXge1 was 100% and 63.3%, respectively; wXge2, wXge3 and wXge5 were detected from less than 15% of specimens. We performed mitochondrial haplotype analyses that identified three genetic types of X. germanus, i.e. Clades A, B and C. Wsp alleles wXge1, wXge2 and wXge4 were detected in all clade A beetles; wXge2 allele was absent from Clades B and C. We concluded that (i) five wsp alleles were found from X. germanus, (ii) use of MLST genes, rather than the wsp gene, are more suited to construct Wolbachia phylogenies and (iii) wsp alleles wXge2 and wXge3/wXge5 would infect clade A and clade B/C of X. germanus, respectively.