Browsing by Subject "outflows"

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  • Liu, Wei (2006)
    The liberalization of capital outflows could cause an increase, rather than decrease, in capital inflows. The aim of this thesis is to explore the paradox. Empirical evidence from four countries, Spain, New Zealand, Italy and Uruguay, is introduced to illustrate the positive influence of capital-outflow liberalizations on capital inflows. Two models are adopted to offer theoretical explanations from different perspectives as well. The first model suggests that the liberalization of capital outflows could be designed to reduce the minimum capital-repatriation period for foreign investment. With this period length reduction, investors get more freedom to invest and withdraw their capitals. Their "option value" of investing after getting certain about the possible policies changes is lowered. Therefore, they will increase the investment from the beginning period. The second model is about the "signaling effect" of capital-outflow liberalizations. It is based on this asymmetric information system. Investors will regard current capital polices as a signal for future possible polices. Today's liberalization on capital outflows predicts a higher probability of favorable investment polices tomorrow. With the "friendly" capital policies, investors are more confident and then increase their investments. The empirical analysis about China's capital outflow liberalization and its influence on capital inflows is carried out. The VAR model is applied for this empirical analysis. The data used for analysis are mainly from International Monetary Fund and Chinese National Bureau of Statistics. The test result shows that the positive influence of the capital liberalization in China can be expected too.
  • Vilhu, Osmi; Kallman, T. R.; Koljonen, K. I. I.; Hannikainen, D. C (2021)
    Context. The radiatively driven wind of the primary star in wind-fed X-ray binaries can be suppressed by the X-ray irradiation of the compact secondary star. This causes feedback between the wind and the X-ray luminosity of the compact star.Aims. We aim to estimate how the wind velocity on the face-on side of the donor star depends on the spectral state of the high-mass X-ray binary Cygnus X-3.Methods. We modeled the supersonic part of the wind by computing the line force (force multiplier) with the Castor, Abbott & Klein formalism and XSTAR physics and by solving the mass conservation and momentum balance equations. We computed the line force locally in the wind considering the radiation fields from both the donor and the compact star in each spectral state. We solved the wind equations at different orbital angles from the line joining the stars and took the effect of wind clumping into account. Wind-induced accretion luminosities were estimated using the Bondi-Hoyle-Lyttleton formalism and computed wind velocities at the compact star. We compared them to those obtained from observations.Results. We found that the ionization potentials of the ions contributing the most to the line force fall in the extreme-UV region (100-230 angstrom). If the flux in this region is high, the line force is weak, and consequently, the wind velocity is low. We found a correlation between the luminosities estimated from the observations for each spectral state of Cyg X-3 and the computed accretion luminosities assuming moderate wind clumping and a low mass of the compact star. For high wind clumping, this correlation disappears. We compared the XSTAR method used here with the comoving frame method and found that they agree reasonably well with each other.Conclusions. We show that soft X-rays in the extreme-UV region from the compact star penetrate the wind from the donor star and diminish the line force and consequently the wind velocity on the face-on side. This increases the computed accretion luminosities qualitatively in a similar manner as observed in the spectral evolution of Cyg X-3 for a moderate clumping volume filling factor and a compact star mass of a few (2-3) solar masses.