1,365 research outputs found
Why the Poor Play the Lottery: Sociological Approaches to Explaining Class-based Lottery Play
Why do the poor spend more on lottery tickets than their wealthier and better educated peers? While social scientists generally agree that there is an inverse relationship between socio-economic position and patterns of lottery play, there is debate on what factors cause lottery gambling. Using survey data from a nationwide probability sample, we test three sociological approaches – socio-structural, cultural and social network accounts – to explain why the poor play the lottery. While controlling for cognitive bias theory, we find that peer play, educational attainment and self-perceived social deprivation have strong effects on lottery play. Culture, the study finds, plays a much lesser role. Although lottery players demonstrate fatalistic value orientations, it is not a lack of a ‘Protestant’ work ethic that makes the poor spend proportionally more on lottery tickets. The findings of this study generally point to the importance of social structures in explaining lottery gambling.Social Stratification and the Demand for Lottery Tickets Data and Methods Results Conclusion Acknowledgements Notes Reference
Stellar Dynamics at the Galactic Center with an Extremely Large Telescope
We discuss experiments achievable via monitoring of stellar dynamics near the
massive black hole at the Galactic center with a next generation, extremely
large telescope (ELT). Given the likely observational capabilities of an ELT
and current knowledge of the stellar environment at the Galactic center, we
synthesize plausible samples of stellar orbits around the black hole. We use
the Markov Chain Monte Carlo method to evaluate the constraints that orbital
monitoring places on the matter content near the black hole. Results are
expressed as functions of the number N of stars with detectable orbital motions
and the astrometric precision dtheta and spectroscopic precision dv at which
stellar proper motions and radial velocities are monitored. For N = 100, dtheta
= 0.5 mas, and dv = 10 km/s -- a conservative estimate of the capabilities of a
30 meter telescope -- the extended matter distribution enclosed by the orbits
will produce measurable deviations from Keplerian motion if >1000 Msun is
enclosed within 0.01 pc. The black hole mass and distance to the Galactic
center will be measured to better than ~0.1%. Lowest-order relativistic
effects, such as the prograde precession, will be detectable if dtheta < 0.5
mas. Higher-order effects, including frame dragging due to black hole spin,
requires dtheta < 0.05 mas, or the favorable discovery of a compact, highly
eccentric orbit. Finally, we calculate the rate at which monitored stars
undergo detectable nearby encounters with background stars. Such encounters
probe the mass function of stellar remnants that accumulate near the black
hole. We find that ~30 encounters will be detected over a 10 yr baseline for
dtheta = 0.5 mas.Comment: 14 pages, 5 figures; discussion no longer aperture-specific (TMT ->
ELT), matches ApJ versio
Characterization of solar cells for space applications. Volume 11: Electrical characteristics of 2 ohm-cm, 228 micron wraparound solar cells as a function of intensity, temperature, and irradiation
Parametric characterization data on Spectrolab 2 by 4 cm, 2 ohm/cm, 228 micron thick wraparound cell, a candidate for the Solar Electric Propulsion Mission, are presented. These data consist of the electrical characteristics of the solar cell under a wide range of temperature and illumination intensity combinations of the type encountered in space applications
High-Spatial Resolution SED of NGC 1068 from Near-IR to Radio. Disentangling the thermal and non-thermal contributions
We investigate the ideas that a sizable fraction of the interferometrically
unresolved infrared emission of the nucleus of NGC 1068 might originate from
other processes than thermal dust emission from the torus. We examine the
contribution of free-free or synchrotron emissions to the central mid- and
near-IR parsec-scale emitting region of NGC 1068. Each mechanism is constrained
with parsec scale radio data available for NGC 1068 in the 10^9 - 10^11 Hz
regime, and compared to the highest-resolution interferometric data available
in the mid-infrared. It is shown that the unresolved emission in the
interferometric observation (<~1pc) is still dominatedd by dust emission and
not by contributions from synchrotron or free-free emission. As recent studies
suggest, the interferometric observations prefer a clumpy structure of the dust
distribution. Extrapolation of the radio free-free or synchrotron emission to
the IR indicates that their contribution is <20% even for the unresolved
fraction of the interferometric flux. The slope of the available radio data is
consistent with a power law exponent alpha = 0.29 +/- 0.07 which we interprete
in terms of either free-free emission or synchrotron radiation from
quasi-monochromatic electrons. We apply emission models for both mechanisms in
order to obtain physical parameters. (abridged)Comment: 8 pages, 3 figures; accepted by A&
High Proper Motion Stars in the Vicinity of Sgr A*: Evidence for a Supermassive Black Hole at the Center of Our Galaxy
Over a two year period (1995-1997), we have conducted a diffraction-limited
imaging study at 2.2 microns of the inner 6"x6" of the Galaxy's central stellar
cluster using the Keck 10-m telescope. The K band images obtained reveal a
large population of faint stars. We use an unbiased approach for identifying
and selecting stars to be included in this proper motion study, which results
in a sample of 90 stars with brightness ranging from K=9-17 and velocities as
large as 1,400+-100 km/sec. Compared to earlier work (Eckart et al. 1997;
Genzel et al. 1997), the source confusion is reduced by a factor of 9, the
number of stars with proper motion measurement in the central 25 arcsec^2 of
our galaxy is doubled, and the accuracy of the velocity measurements in the
central 1 arcsec^2 is improved by a factor of 4. The peaks of both the stellar
surface density and the velocity dispersion are consistent with the position of
the unusual radio source and blackhole candidate, Sgr A*, suggesting that Sgr
A* is coincident (+-0."1) with the dynamical center of the Galaxy. As a
function of distance from Sgr A*, the velocity dispersion displays a falloff
well fit by Keplerian motion about a central dark mass of 2.6(+-0.2)x10^6 Mo
confined to a volume of at most 10^-6 pc^3, consistent with earlier results.
Although uncertainties in the measurements mathematically allow for the matter
to be distributed over this volume as a cluster, no realistic cluster is
physically tenable. Thus, independent of the presence of Sgr A*, the large
inferred central density of at least 10^12 Mo/pc^3, which exceeds the
volume-averaged mass densities found at the center of any other galaxy, leads
us to the conclusion that our Galaxy harbors a massive central black hole.Comment: 19 pages, 8 figures, accepted for publications in the Astrophysical
Journa
Characterization of solar cells for space applications. Volume 12: Electrical characteristics of Solarex BSF, 2-ohm-cm, 50-micron solar cells (1978 pilot line) as a function of intensity, temperature, and irradiation
Electrical characteristics of Solarex back-surface-field, 2-ohm-cm, 50-micron N/P silicon solar cells are presented in graphical and tabular format as a function of solar illumination intensity, temperature, and irradiation
Characterization of solar cells for space applications. Volume 8: Electrical characteristics of Spectrolab BSF, BSR, textured 290-micron solar cells (K7) as a function of intensity, temperature and irradiation
A set of parametric data is presented on the Spectrolab textured, back-surface-field, back-surface-reflector solar cell which is a commercially available product
Estimativa de parâmetros de crescimento, produção e dinâmica de um fragmento de Floresta com Araucária usando dados de parcelas permanentes.
Editores técnicos: MarcÃlio José Thomazini, Elenice Fritzsons, PatrÃcia Raquel Silva, Guilherme Schnell e Schuhli, Denise Jeton Cardoso, Luziane Franciscon. EVINCI. Resumos
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