706 research outputs found

    MHD simulations of dense core collision

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    We investigated the effect of magnetic fields on the collision process between dense molecular cores. We performed three-dimensional magnetohydrodynamic simulations of collisions between two self-gravitating cores using the Enzo adaptive mesh refinement code. The core was modeled as a stable isothermal Bonnor-Ebert (BE) sphere immersed in uniform magnetic fields. Collisions were characterized by the offset parameter bb, Mach number of the initial core M\mathcal{M}, magnetic field strength B0B_{0}, and angle θ\theta between the initial magnetic field and collision axis. For head-on (b=0b = 0) collisions, one protostar was formed in the compressed layer. The higher the magnetic field strength, the lower the accretion rate. For models with b=0b = 0 and θ=90\theta = 90^{\circ}, the accretion rate was more dependent on the initial magnetic field strength compared with b=0b = 0 and θ=0\theta = 0^{\circ} models. For off-center (b=1b = 1) collisions, the higher specific angular momentum increased; therefore, the gas motion was complicated. In models with b=1b = 1 and M=1\mathcal{M} = 1, the number of protostars and gas motion highly depended on B0B_{0} and θ\theta. For models with b=1b = 1 and M=3\mathcal{M} = 3, no significant shock-compressed layer was formed and star formation was not triggered.Comment: 20 pages, 18 figures, 3 tables. Accepted for publication in Ap

    Patent Litigation in Japan

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    This article will explore how patent litigation in Japan has changed and will also compare and contrast aspects of patent litigation in the U.S. and Japan. In Part II, we show recent statistical data on Japanese patent infringement litigation. Parts III and IV briefly review the Japanese judicial system and legal professionals in the area of intellectual property. Part V addresses patent-infringement actions in Japan and the recent amendments of the Code of Civil Procedure and the Patent Law. Next, Parts VI and VII discuss infringement analysis and possible defenses in patent-infringement litigation. Part VIII reviews how to calculate the amount of damages in patent litigation in Japan. Finally, Part IX discusses provisional injunctions in Japan

    Unveiling the Dynamics of Dense Cores in Cluster-Forming Clumps: A 3D MHD Simulation Study of Angular Momentum and Magnetic Field Properties

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    We conducted isothermal MHD simulations with self-gravity to investigate the properties of dense cores in cluster-forming clumps. Two different setups were explored: a single rotating clump and colliding clumps. We focused on determining the extent to which the formed dense cores inherit the rotation and magnetic field of the parental clump. Our statistical analysis revealed that the alignment between the angular momentum of dense cores, Lcore\bf{L}_{\rm core}, and the rotational axis of the clump is influenced by the strength of turbulence and the simulation setup. In single rotating clumps, we found that Lcore\bf{L}_{\rm core} tends to align with the clump's rotational axis if the initial turbulence is weak. However, in colliding clumps, this alignment does not occur, regardless of the initial turbulence strength. This misalignment in colliding clumps is due to the induced turbulence from the collision and the isotropic gas inflow into dense cores. Our analysis of colliding clumps also revealed that the magnetic field globally bends along the shock-compressed layer, and the mean magnetic field of dense cores, Bcore\bf{B}_{\rm core}, aligns with it. Both in single rotating clumps and colliding clumps, we found that the angle between Bcore\bf{B}_{\rm core} and Lcore\bf{L}_{\rm core} is generally random, regardless of the clump properties. We also analyzed the dynamical states of the formed cores and found a higher proportion of unbound cores in colliding clumps. In addition, the contribution of rotational energy was only approximately 5% of the gravitational energy, regardless of the model parameters for both single and colliding cases.Comment: 28 pages, 25 figures, 3 tables. Accepted for publication in Ap

    Lasing from a single quantum wire

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    A laser with an active volume consisting of only a single quantum wire in the 1-dimensional (1-D) ground state is demonstrated. The single wire is formed quantum-mechanically at the T-intersection of a 14 nm Al_{0.07}Ga_{0.93}As quantum well and a 6 nm GaAs quantum well, and is embedded in a 1-D single-mode optical waveguide. We observe single-mode lasing from the quantum wire ground state by optical pumping. The laser operates from 5 to 60 K, and has a low threshold pumping power of 5 mW at 5 K.Comment: 4 pages including 4 figure

    Imaging of emission patterns in a T-shaped quantum wire laser

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    Spatially and spectrally resolved microscopic images of spontaneous and stimulated emissions are imaged at the mirror facets of a GaAs T-shaped quantum wire laser with high uniformity. Laser emission from the one-dimensional ground state reveals a circular image located at the core of a T-shaped optical waveguide but significantly smaller in area than the low power spontaneous emission from the same waveguide. These images unambiguously allow assignment of all spontaneous and laser emissions to the wire ground state and respective intersecting wells in the structure.Comment: 4 pages, 3 figure

    New Attempt at Preparation of Fluorine-containing Poly(ether ketone)s in Supercritical Carbon Dioxide

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    Fluorine-containing poly(ether ketone)s was synthesized by the nucleophilic aromatic substitution reaction of 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane and 4,4'-bis(2,3,4,5,6-pentafluorobenzoyl) diphenyl ether in super-critical CO(2). Polymerizations were carried out at 80℃ for 6 hours under 5000 psi of CO(2) pressure, which was super-critical phase. Polymerization concentration was 0.5 g of polymer in 10 - 12 mL of CO(2). The polymer was not obtained in CO(2) due to the insolubility of both the potassium bisphenoxide and the polymer into CO(2). However, the polymer was formed by an addition of DMAc and NMP in CO(2), even though molecular weight was not so high. Very small amount of co-solvents which were immiscible with CO(2) was effective, and it was 1/20 - 1/25 amount of the solvent used in the conventional poly(ether ketone) synthesis. The polymerization mechanism was also discussed

    Sex differences in life history, behavior, and physiology along a slow-fast continuum: a meta-analysis

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    Tarka M, Günther A, Niemelae PT, Nakagawa S, Noble DWA. Sex differences in life history, behavior, and physiology along a slow-fast continuum: a meta-analysis. BEHAVIORAL ECOLOGY AND SOCIOBIOLOGY. 2018;72(8): UNSP 132.The pace-of-life syndrome (POLS) hypothesis predicts that behavior and physiology covary with life history. Evidence for such covariation is contradictory, possibly because systematic sources of variation (e.g. sex) have been neglected. Sexes often experience different selection pressures leading to sex-specific allocation between reproduction and self-maintenance, facilitating divergence in life-history. Sex-specific differences in means and possibly variances may therefore play a key role in the POLS framework. We investigate whether sexes differ in means and variances along the fast-slow pace-of-life continuum for life history and physiological and behavioral traits. In addition, we test whether social and environmental characteristics such as breeding strategy, mating system, and study environment explain heterogeneity between the sexes. Using meta-analytic methods, we found that populations with a polygynous mating system or for studies conducted on wild populations, males had a faster pace-of-life for developmental life-history traits (e.g., growth rate), behavior, and physiology. In contrast, adult life-history traits (e.g., lifespan) were shifted towards faster pace-of-life in females, deviating from the other trait categories. Phenotypic variances were similar between the sexes across trait categories and were not affected by mating system or study environment. Breeding strategy did not influence sex differences in variances or means. We discuss our results in the light of sex-specific selection that might drive sex-specific differences in pace-of-life and ultimately POLS

    Immunohistochemical Distribution of Serum Proteins in Living Mouse Heart with In Vivo Cryotechnique

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    In vivo cryotechnique (IVCT), which immediately cryofixes target organs in situ, was used to clarify the morphological features of beating heart tissue of living mice. IVCT was performed for diastolic heart tissue under the condition of monitoring with electrocardiogram (ECG). Other mouse hearts were prepared with conventional perfusion-fixation (PF-DH) or immersion-fixation followed by dehydration (IM-DH), and quick-freezing of resected heart tissues (FQF). Immunolocalizations of albumin, immunoglobulin G1 (IgG1), intravenously injected bovine serum albumin (BSA), and connexin 43 were examined after different intervals of BSA injection. In the case of IVCT, the exact stop time of beating mouse hearts was recorded by ECG, and open blood vessels with flowing erythrocytes were observed with less artificial tissue shrinkage than with conventional preparation methods. Both albumin and BSA were well preserved in intercalated discs and t-tubules of cardiomyocytes in addition to blood vessels and interstitial matrices. IgG1 was immunolocalized in interstitial matrices of heart tissues in addition to their blood vessels. At 4 hr after BSA injection, it was immunolocalized in the intercalated discs of cardiomyocytes and lost later at 8 hr. IVCT should prove to be more useful for the morphofunctional examination of dynamically changing heart tissue than conventional preparation methods
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