20,316 research outputs found

    The Propensity To Continue Service Internationalization - A Model Of Planned Behavior

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    The present study investigates the propensity to continue internationalization by experienced international service providers. Enhancing the cognitive-behavioral root of internationalization process theory (Johanson and Vahlne 1977; 1990), this paper builds upon Ajzen’s (1991) theory of planned behavior. Consistent with the latter theory, the propensity to continue service internationalization is modelled as behavioral intention that results from (1) an overall attitude towards internationalization, (2) structural and strategic behavioral norms, and (3) inhibiting factors that exert behavioral control upon propensity. Using partial least squares analysis, a propensity model is tested on a sample of 193 international service providers. The results suggest that our model explicates and enhances the cognitive/affective character of internationalization process theory.management and organization theory ;

    Magnetic defects promote ferromagnetism in Zn1-xCoxO

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    Experimental studies of Zn1-xCoxO as thin films or nanocrystals have found ferromagnetism and Curie temperatures above room temperature and that p- or n-type doping of Zn1-xCoxO can change its magnetic state. Bulk Zn1-xCoxO with a low defect density and x in the range used in experimental thin film studies exhibits ferromagnetism only at very low temperatures. Therefore defects in thin film samples or nanocrystals may play an important role in promoting magnetic interactions between Co ions in Zn1-xCoxO. The electronic structures of Co substituted for Zn in ZnO, Zn and O vacancies, substituted N and interstitial Zn in ZnO were calculated using the B3LYP hybrid density functional in a supercell. The B3LYP functional predicts a band gap of 3.34 eV for bulk ZnO, close to the experimental value of 3.47 eV. Occupied minority spin Co 3d levels are at the top of the valence band and unoccupied levels lie above the conduction band minimum. Majority spin Co 3d levels hybridize strongly with bulk ZnO states. The neutral O vacancy and interstitial Zn are deep and shallow donors, respectively. The Zn vacancy is a deep acceptor and the acceptor level for substituted N is at mid gap. The possibility that p- or n-type dopants promote exchange coupling of Co ions was investigated by computing total energies of magnetic states of ZnO supercells containing two Co ions and an oxygen vacancy, substituted N or interstitial Zn in various charge states. The neutral N defect and the singly-positively charged O vacancy are the only defects which strongly promote ferromagnetic exchange coupling of Co ions at intermediate range.Comment: 9 pages, 11 figure

    The Frequency of Rapid Rotation Among K Giant Stars

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    We present the results of a search for unusually rapidly rotating giant stars in a large sample of K giants (~1300 stars) that had been spectroscopically monitored as potential targets for the Space Interferometry Mission's Astrometric Grid. The stars in this catalog are much fainter and typically more metal-poor than those of other catalogs of red giant star rotational velocities, but the spectra generally only have signal-to-noise (S/N) of ~20-60, making the measurement of the widths of individual lines difficult. To compensate for this, we have developed a cross-correlation method to derive rotational velocities in moderate S/N echelle spectra to efficiently probe this sample for rapid rotator candidates. We have discovered 28 new red giant rapid rotators as well as one extreme rapid rotator with a vsini of 86.4 km/s. Rapid rotators comprise 2.2% of our sample, which is consistent with other surveys of brighter, more metal-rich K giant stars. Although we find that the temperature distribution of rapid rotators is similar to that of the slow rotators, this may not be the case with the distributions of surface gravity and metallicity. The rapid rotators show a slight overabundance of low gravity stars and as a group are significantly more metal-poor than the slow rotators, which may indicate that the rotators are tidally-locked binaries.Comment: Accepted for publication in ApJ. 25 pages, 9 figures, 3 tables. Tables 1 and 2 are provided in their full form as plain text ancillary file

    WZ Sagittae as a DQ Herculis star

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    We argue that quiescent WZ Sge is a rapidly spinning magnetic rotator in which most of the matter transfered from the secondary is ejected from the system. Assuming that the observed 27.87 s oscillation period is due to the spinning white dwarf we propose that the other observed principal period of 28.96 s is a beat due to reprocessing of the rotating white dwarf beam on plasma blobs in Keplerian rotation at the outer disc rim. The weaker, transient, 29.69 s period is identified as a beat with the Keplerian period of the magnetosphere. WZ Sge evolves through a cycle of spin-up and spin-down phases. During the spin-down phase it is a DQ Her star, during the spin-up phase it should be a ER UMa star.Comment: 8 pages, 5 figures; accepted for publication in MNRA

    Cold and Slow Molecular Beam

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    Employing a two-stage cryogenic buffer gas cell, we produce a cold, hydrodynamically extracted beam of calcium monohydride molecules with a near effusive velocity distribution. Beam dynamics, thermalization and slowing are studied using laser spectroscopy. The key to this hybrid, effusive-like beam source is a "slowing cell" placed immediately after a hydrodynamic, cryogenic source [Patterson et al., J. Chem. Phys., 2007, 126, 154307]. The resulting CaH beams are created in two regimes. One modestly boosted beam has a forward velocity of vf = 65 m/s, a narrow velocity spread, and a flux of 10^9 molecules per pulse. The other has the slowest forward velocity of vf = 40 m/s, a longitudinal temperature of 3.6 K, and a flux of 5x10^8 molecules per pulse

    The minimum period problem in cataclysmic variables

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    We investigate if consequential angular momentum losses (CAML) or an intrinsic deformation of the donor star in CVs could increase the CV bounce period from the canonical theoretical value ~65 min to the observed value Pmin≈77P_{min} \approx77 min, and if a variation of these effects in a CV population could wash out the theoretically predicted accumulation of systems near the minimum period (the period spike). We are able to construct suitably mixed CV model populations that a statisticial test cannot rule out as the parent population of the observed CV sample. However, the goodness of fit is never convincing, and always slightly worse than for a simple, flat period distribution. Generally, the goodness of fit is much improved if all CVs are assumed to form at long orbital periods. The weighting suggested by King, Schenker & Hameury (2002) does not constitute an improvment if a realistically shaped input period distribution is used. Put your abstract here.Comment: 10 pages, Latex, 13 postscript figures, Accepted for publication in MNRA
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