28,538 research outputs found
Pebble Mine: Fish, Minerals, and Testing the Limits of Alaska’s “Large Mine Permitting Process”
After heat distribution of a mobile nuclear power plant
A computer program was developed to analyze the transient afterheat temperature and pressure response of a mobile gas-cooled reactor power plant following impact. The program considers (in addition to the standard modes of heat transfer) fission product decay and transport, metal-water reactions, core and shield melting and displacement, and pressure and containment vessel stress response. Analyses were performed for eight cases (both deformed and undeformed models) to verify operability of the program options. The results indicated that for a 350 psi (241 n/sq cm) initial internal pressure, the containment vessel can survive over 100,000 seconds following impact before creep rupture occurs. Recommendations were developed as to directions for redesign to extend containment vessel life
On the formation of current sheets in response to the compression or expansion of a potential magnetic field
The compression or expansion of a magnetic field that is initially potential
is considered. It was recently suggested by Janse & Low [2009, ApJ, 690, 1089]
that, following the volumetric deformation, the relevant lowest energy state
for the magnetic field is another potential magnetic field that in general
contains tangential discontinuities (current sheets). Here we examine this
scenario directly using a numerical relaxation method that exactly preserves
the topology of the magnetic field. It is found that of the magnetic fields
discussed by Janse & Low, only those containing magnetic null points develop
current singularities during an ideal relaxation, while the magnetic fields
without null points relax toward smooth force-free equilibria with finite
non-zero current.Comment: Accepted for publication in Ap
Gap Symmetry of Superconductivity in UPd2Al3
The angle dependent thermal conductivity of the heavy-fermion superconductor
UPdAl in the vortex state was recently measured by Watanabe et al. Here
we analyze this data from two perspectives: universal heat conduction and the
angle-dependence. We conclude that the superconducting gap function
in UPdAl has horizontal nodes and is given by
, with .Comment: 8 pages, 4 figures, improved figures in replacemen
Management of Chronic Non-malignant Pain in Nursing Homes Residents
Pain in nursing homes remains underassessed, underreported and undertreated, consequently, becoming a growing concern in the United States. The purpose of this inquiry is to review the current evidence guiding the management of chronic non-malignant pain among nursing home residents. Twelve articles relevant to this topic were obtained from a search of the electronic databases PubMed and Cumulative Index of Nursing and Allied Health (CINAHL). Findings underscore an urgent need to improve assessment, documentation, and management of pain in nursing home residents
Section 404(c) of the Clean Water Act and the History of State and Federal Efforts to Conserve the Kvichak and Nushagak Drainages of Alaska
Section 404(c) of the Clean Water Act and the History of State and Federal Efforts to Conserve the Kvichak and Nushagak Drainages of Alaska
Quantum incompressibility of a falling Rydberg atom, and a gravitationally-induced charge separation effect in superconducting systems
Freely falling point-like objects converge towards the center of the Earth.
Hence the gravitational field of the Earth is inhomogeneous, and possesses a
tidal component. The free fall of an extended quantum object such as a hydrogen
atom prepared in a high principal-quantum-number stretch state, i.e., a
circular Rydberg atom, is predicted to fall more slowly that a classical
point-like object, when both objects are dropped from the same height from
above the Earth. This indicates that, apart from "quantum jumps," the atom
exhibits a kind of "quantum incompressibility" during free fall in
inhomogeneous, tidal gravitational fields like those of the Earth. A
superconducting ring-like system with a persistent current circulating around
it behaves like the circular Rydberg atom during free fall. Like the electronic
wavefunction of the freely falling atom, the Cooper-pair wavefunction is
"quantum incompressible." The ions of the ionic lattice of the superconductor,
however, are not "quantum incompressible," since they do not possess a globally
coherent quantum phase. The resulting difference during free fall in the
response of the nonlocalizable Cooper pairs of electrons and the localizable
ions to inhomogeneous gravitational fields is predicted to lead to a charge
separation effect, which in turn leads to a large repulsive Coulomb force that
opposes the convergence caused by the tidal, attractive gravitational force on
the superconducting system. A "Cavendish-like" experiment is proposed for
observing the charge separation effect induced by inhomogeneous gravitational
fields in a superconducting circuit. This experiment would demonstrate the
existence of a novel coupling between gravity and electricity via
macroscopically coherent quantum matter.Comment: `2nd Vienna Symposium for the Foundations of Modern Physics'
Festschrift MS for Foundations of Physic
Inverse Scattering Transform for the Camassa-Holm equation
An Inverse Scattering Method is developed for the Camassa-Holm equation. As
an illustration of our approach the solutions corresponding to the
reflectionless potentials are explicitly constructed in terms of the scattering
data. The main difference with respect to the standard Inverse Scattering
Transform lies in the fact that we have a weighted spectral problem. We
therefore have to develop different asymptotic expansions.Comment: 17 pages, LaTe
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