2,748 research outputs found

    P-Cygni Type Lya from Starburst Galaxies

    Get PDF
    P-Cygni type Lya profiles exhibited in nearly half of starburst galaxies, both nearby and high-z, are believed to be formed by an expanding supershell surrounding a star-forming region. We apply the Monte Carlo code which was developed previously for static and plane-parallel medium to calculate the Lya line transfer in a supershell of neutral hydrogen which are expanding radially in a spherical bulk flow. We consider typical cases that the supershell has the Lya line-centre optical depth of Ļ„0=105āˆ’107\tau_0=10^5-10^7, a radial expansion velocity of Vexp=300km/s,andtheturbulenceofb=40km/s.Wefindthatthereappearafewemissionpeaksatthefrequenciescorrespondingto(2Nāˆ’1)Vexp,wheretheorderofbackscatteringsN>1.AsVexpāˆ’>b,theemergentprofilesbecomesimilartothoseforthestaticmediumandthepeaksarelessprominent.WealsoinvestigatetheeffectsofcolumndensityofthesupershellontheemergentLyaprofiles.WefindthatthenumberandthefluxratiosofemissionpeaksaredeterminedbyinterplayofV_exp = 300 km/s, and the turbulence of b=40 km/s. We find that there appear a few emission peaks at the frequencies corresponding to (2N-1) V_exp, where the order of back scatterings N > 1. As V_exp -> b, the emergent profiles become similar to those for the static medium and the peaks are less prominent. We also investigate the effects of column density of the supershell on the emergent Lya profiles. We find that the number and the flux ratios of emission peaks are determined by interplay of \tau_0$ and V_exp of the supershell. We discuss the effects of dust extinction and the implication of our works in relation to recent spectroscopic observations of starburst galaxies.Comment: 15 pages, 6 figures, submitted to MNRA

    Quasi-Eigenstate Evolution in Open Chaotic Billiards

    Full text link
    We experimentally studied evolution of quasi-eigenmodes as classical dynamics undergoing a transition from being regular to chaotic in open quantum billiards. In a deformation-variable microcavity we traced all high-Q cavity modes in a wide range of frequency as the cavity deformation increased. By employing an internal parameter we were able to obtain a mode-dynamics diagram at a given deformation, showing avoided crossings between different mode groups, and could directly observe the coupling strengths induced by ray chaos among encountering modes. We also show that the observed mode-dynamics diagrams reflect the underlying classical ray dynamics in the phase space.Comment: 4 pages, 4 figure

    Development of deformation-tunable quadrupolar microcavity

    Full text link
    We have developed a technique for realizing a two-dimensional quadrupolar microcavity with its deformation variable from 0% to 20% continuously. We employed a microjet ejected from a noncircular orifice in order to generate a stationary column with modulated quadrupolar deformation in its cross section. Wavelength red shifts of low-order cavity modes due to shape deformation were measured and were found to be in good agreement with the wave calculation for the same deformation, indicating the observed deformation is quadrupolar in nature.Comment: 7 pages, 6 figures, intended for Rev. Sci. Instu

    AMPK-Dependent Metabolic Regulation by PPAR Agonists

    Get PDF
    Comprehensive studies support the notion that the peroxisome proliferator-activated receptors, (PPARs), PPARĪ±, PPARĪ²/Ī“, and PPARĪ³, regulate cell growth, morphogenesis, differentiation, and homeostasis. Agonists of each PPAR subtype exert their effects similarly or distinctly in different tissues such as liver, muscle, fat, and vessels. It is noteworthy that PPARĪ± or PPARĪ³ agonists have pharmacological effects by modulating the activity of AMPK, which is a key cellular energy sensor. However, the role of AMPK in the metabolic effects of PPAR agonists has not been thoroughly focused. Moreover, AMPK activation by PPAR agonists seems to be independent of the receptor activation. This intriguing action of PPAR agonists may account in part for the mechanistic basis of the therapeutics in the treatment of metabolic disease. In this paper, the effects of PPAR agonists on metabolic functions were summarized with particular reference to their AMPK activity regulation

    Ultrahigh areal number density solid-state on-chip microsupercapacitors via electrohydrodynamic jet printing

    Get PDF
    Microsupercapacitors (MSCs) have garnered considerable attention as a promising power source for microelectronics and miniaturized portable/wearable devices. However, their practical application has been hindered by the manufacturing complexity and dimensional limits. Here, we develop a new class of ultrahigh areal number density solid-state MSCs (UHD SS-MSCs) on a chip via electrohydrodynamic (EHD) jet printing. This is, to the best of our knowledge, the first study to exploit EHD jet printing in the MSCs. The activated carbon-based electrode inks are EHD jet-printed, creating interdigitated electrodes with fine feature sizes. Subsequently, a drying-free, ultraviolet-cured solid-state gel electrolyte is introduced to ensure electrochemical isolation between the SS-MSCs, enabling dense SS-MSC integration with on-demand (in-series/in-parallel) cell connection on a chip. The resulting on-chip UHD SS-MSCs exhibit exceptional areal number density [36 unit cells integrated on a chip (area = 8.0 mm x 8.2 mm), 54.9 cells cm(-2)] and areal operating voltage (65.9 V cm(-2))

    Chaos-assisted nonresonant optical pumping of quadrupole-deformed microlasers

    Full text link
    Efficient nonresonant optical pumping of a high-Q scar mode in a two-dimensional quadrupole-deformed microlaser has been demonstrated based on ray and wave chaos. Three-fold enhancement in the lasing power was achieved at a properly chosen pumping angle. The experimental result is consistent with ray tracing and wave overlap integral calculations.Comment: 3 pages, 5 figure

    An Empirical Study on the Importance of Psychological Contract Commitment in Information Systems Outsourcing

    Get PDF
    In IS outsourcing relationship literature, research has focused on detailed legal contracts and partnerships. We investigate the role of psychological contracts between client and vendor in the IS outsourcing context. The aim of this paper is to put the concept ā€œpsychological contract commitmentā€ (PCC) under the spotlight, finding out its mediating effects between legal contracts/partnerships and IS outsourcing success. By analyzing 50 matched survey responses gathered from project managers, vendor firms, and end-users, we found that psychological contract commitment has both direct and mediating effects on outsourcing success. Along the same lines, the key findings suggest that psychological contract commitment explains why legal contracts and partnerships are still crucial to IS outsourcing success
    • ā€¦
    corecore