763 research outputs found
Turning to God in the Face of Ostracism: Effects of Social Exclusion on Religiousness
The present research proposes that individuals who are socially excluded can turn to religion to cope with the experience. Empirical studies conducted to test this hypothesis consistently found that socially excluded persons reported (a) significantly higher levels of religious affiliation (Studies 1, 2, and 4) and (b) stronger intentions to engage in religious behaviors (Study 2) than comparable, nonexcluded individuals. Direct support for the stress-buffering function of religiousness was also found, with a religious prime reducing the aggression-eliciting effects of consequent social rejection (Study 5). These effects were observed in both Christian and Muslim samples, revealing that turning to religion can be a powerful coping response when dealing with social rejection. Theoretical and practical implications of these findings are discussed
Observer dependence for the phonon content of the sound field living on the effective curved space-time background of a Bose-Einstein condensate
We demonstrate that the ambiguity of the particle content for quantum fields
in a generally curved space-time can be experimentally investigated in an
ultracold gas of atoms forming a Bose-Einstein condensate. We explicitly
evaluate the response of a suitable condensed matter detector, an ``Atomic
Quantum Dot,'' which can be tuned to measure time intervals associated to
different effective acoustic space-times. It is found that the detector
response related to laboratory, ``adiabatic,'' and de Sitter time intervals is
finite in time and nonstationary, vanishing, and thermal, respectively.Comment: 9 pages, 2 figures; references updated, as published in Physical
Review
LABORATORY INVESTIGATIONS IN SUPPORT OF FLUID BED FLUORIDE VOLATILITY PROCESSES. PART IV. THE FLUID BED FLUORINATION OF UO
In one of the processes under development, the uranium and plutonium content of a spent reactor fuel of the Dresden type would be fluorinated in a fluid-bed reactor to produce the volatile uranium and plutonium hexafluorides. The study of the fluorination of U/sub 3/O/sub 8/ was undertaken because it is the major product obtained in an oxidative decladding step that is being proposed for the removal of uranium and plutonium from stainless steel-clad and Zircaloy- clad fuel elements. The study Will also provide data needed for the development of apparatus and procedures for future work with mixtures of uranosic oxide and plutoniam dioxide. Experiments were performed to determine the optimum reaction conditions for the conversion of U/sub 3/O/sub 8/ to uranium hexafluoride and for minimizing the elutriation of unreacted U/sub 3/O/sub 8/ from the fluid bed. Elutriation of U/sub 3/O/sub 8/ from the fluid bed was minimized when a fluid bed height of 8 in. of 120 mesh alumina, a fluorinating gas phase containing 20 vol% fluorine, and a reaction temperature of 500 deg C were employed. Conversion of greater than 99% of the U/sub 3/O/sub 8/ to uranium hexafluoride was obtained when the feeding-fluorination period, in w,hich the U/sub 3/O/sub 8/ powder was fed into the fluid bed and the major part of the fluorination was accomplished by reacting the oxide with 20 vol % fluorine, was followed by a recycle-fluorination period of 5 hr at 500 deg C with 100% fluorine. Kinetic data for the fluorination of U/sub 3/O/sub 8/, obtained by means of a thermobalance, are reported for the temperature range from 300 to 400 deg C. The data were treated by the diminishing-sphere model. Experimental results are also presented for the oxidative decladding of stainless steelclad and Zircaloy-clad uranium dioxide pellets. (auth
A gauge model for quantum mechanics on a stratified space
In the Hamiltonian approach on a single spatial plaquette, we construct a
quantum (lattice) gauge theory which incorporates the classical singularities.
The reduced phase space is a stratified K\"ahler space, and we make explicit
the requisite singular holomorphic quantization procedure on this space. On the
quantum level, this procedure furnishes a costratified Hilbert space, that is,
a Hilbert space together with a system which consists of the subspaces
associated with the strata of the reduced phase space and of the corresponding
orthoprojectors. The costratified Hilbert space structure reflects the
stratification of the reduced phase space. For the special case where the
structure group is , we discuss the tunneling probabilities
between the strata, determine the energy eigenstates and study the
corresponding expectation values of the orthoprojectors onto the subspaces
associated with the strata in the strong and weak coupling approximations.Comment: 38 pages, 9 figures. Changes: comments on the heat kernel and
coherent states have been adde
An action for the exact string black hole
A local action is constructed describing the exact string black hole
discovered by Dijkgraaf, Verlinde and Verlinde in 1992. It turns out to be a
special 2D Maxwell-dilaton gravity theory, linear in curvature and field
strength. Two constants of motion exist: mass M>1, determined by the level k,
and U(1)-charge Q>0, determined by the value of the dilaton at the origin. ADM
mass, Hawking temperature T_H \propto \sqrt{1-1/M} and Bekenstein-Hawking
entropy are derived and studied in detail. Winding/momentum mode duality
implies the existence of a similar action, arising from a branch ambiguity,
which describes the exact string naked singularity. In the strong coupling
limit the solution dual to AdS_2 is found to be the 5D Schwarzschild black
hole. Some applications to black hole thermodynamics and 2D string theory are
discussed and generalizations - supersymmetric extension, coupling to matter
and critical collapse, quantization - are pointed out.Comment: 41 pages, 2 eps figures, dedicated to Wolfgang Kummer on occasion of
his Emeritierung; v2: added ref; v3: extended discussion in sections 3.2, 3.3
and at the end of 5.3 by adding 2 pages of clarifying text; updated refs;
corrected typo
Kepler-22b: A 2.4 Earth-radius Planet in the Habitable Zone of a Sun-like Star
A search of the time-series photometry from NASA's Kepler spacecraft reveals
a transiting planet candidate orbiting the 11th magnitude G5 dwarf KIC 10593626
with a period of 290 days. The characteristics of the host star are well
constrained by high-resolution spectroscopy combined with an asteroseismic
analysis of the Kepler photometry, leading to an estimated mass and radius of
0.970 +/- 0.060 MSun and 0.979 +/- 0.020 RSun. The depth of 492 +/- 10ppm for
the three observed transits yields a radius of 2.38 +/- 0.13 REarth for the
planet. The system passes a battery of tests for false positives, including
reconnaissance spectroscopy, high-resolution imaging, and centroid motion. A
full BLENDER analysis provides further validation of the planet interpretation
by showing that contamination of the target by an eclipsing system would rarely
mimic the observed shape of the transits. The final validation of the planet is
provided by 16 radial velocities obtained with HIRES on Keck 1 over a one year
span. Although the velocities do not lead to a reliable orbit and mass
determination, they are able to constrain the mass to a 3{\sigma} upper limit
of 124 MEarth, safely in the regime of planetary masses, thus earning the
designation Kepler-22b. The radiative equilibrium temperature is 262K for a
planet in Kepler-22b's orbit. Although there is no evidence that Kepler-22b is
a rocky planet, it is the first confirmed planet with a measured radius to
orbit in the Habitable Zone of any star other than the Sun.Comment: Accepted to Ap
Magnetoelectric ordering of BiFeO3 from the perspective of crystal chemistry
In this paper we examine the role of crystal chemistry factors in creating
conditions for formation of magnetoelectric ordering in BiFeO3. It is generally
accepted that the main reason of the ferroelectric distortion in BiFeO3 is
concerned with a stereochemical activity of the Bi lone pair. However, the lone
pair is stereochemically active in the paraelectric orthorhombic beta-phase as
well. We demonstrate that a crucial role in emerging of phase transitions of
the metal-insulator, paraelectric-ferroelectric and magnetic disorder-order
types belongs to the change of the degree of the lone pair stereochemical
activity - its consecutive increase with the temperature decrease. Using the
structural data, we calculated the sign and strength of magnetic couplings in
BiFeO3 in the range from 945 C down to 25 C and found the couplings, which
undergo the antiferromagnetic-ferromagnetic transition with the temperature
decrease and give rise to the antiferromagnetic ordering and its delay in
regard to temperature, as compared to the ferroelectric ordering. We discuss
the reasons of emerging of the spatially modulated spin structure and its
suppression by doping with La3+.Comment: 18 pages, 5 figures, 3 table
Quantum regression theorem for non-Markovian Lindblad equations
We find the conditions under which a quantum regression theorem can be
assumed valid for non-Markovian master equations consisting in Lindblad
superoperators with memory kernels. Our considerations are based on a
generalized Born-Markov approximation, which allows us to obtain our results
from an underlying Hamiltonian description. We demonstrate that a non-Markovian
quantum regression theorem can only be granted in a stationary regime if the
dynamics satisfies a quantum detailed balance condition. As an example we study
the correlations of a two level system embedded in a complex structured
reservoir and driven by an external coherent field.Comment: 14 pages, 5 figures. Extended version. The GBMA is deduced from
projector technique. A new appendix is adde
An improved method for measuring muon energy using the truncated mean of dE/dx
The measurement of muon energy is critical for many analyses in large
Cherenkov detectors, particularly those that involve separating
extraterrestrial neutrinos from the atmospheric neutrino background. Muon
energy has traditionally been determined by measuring the specific energy loss
(dE/dx) along the muon's path and relating the dE/dx to the muon energy.
Because high-energy muons (E_mu > 1 TeV) lose energy randomly, the spread in
dE/dx values is quite large, leading to a typical energy resolution of 0.29 in
log10(E_mu) for a muon observed over a 1 km path length in the IceCube
detector. In this paper, we present an improved method that uses a truncated
mean and other techniques to determine the muon energy. The muon track is
divided into separate segments with individual dE/dx values. The elimination of
segments with the highest dE/dx results in an overall dE/dx that is more
closely correlated to the muon energy. This method results in an energy
resolution of 0.22 in log10(E_mu), which gives a 26% improvement. This
technique is applicable to any large water or ice detector and potentially to
large scintillator or liquid argon detectors.Comment: 12 pages, 16 figure
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