748 research outputs found
Advance care planning in 21st century Australia: a systematic review and appraisal of online advance care directive templates against national framework criteria
Objectives A drive to promote advance care planning at a population level has led to a proliferation of online advance care directive (ACD) templates but little information to guide consumer choice. The current study aimed to appraise the quality of online ACD templates promoted for use in Australia.
Methods A systematic review of online Australian ACD templates was conducted in February 2014. ACD templates were identified via Google searches, and quality was independently appraised by two reviewers against criteria from the 2011 report A National Framework for Advance Care Directives. Bias either towards or against future medical treatment was assessed using criteria designed to limit subjectivity.
Results Fourteen online ACD templates were included, all of which were available only in English. Templates developed by Southern Cross University best met the framework criteria. One ACD template was found to be biased against medical treatment â the Dying with Dignity Victoria Advance Healthcare Directive.
Conclusions More research is needed to understand how online resources can optimally elicit and record consumersâ individual preferences for future care. Future iterations of the framework should address online availability and provide a simple rating system to inform choice and drive quality improvement
Imprints of the nuclear symmetry energy on gravitational waves from the axial w-modes of neutron stars
The eigen-frequencies of the axial w-modes of oscillating neutron stars are
studied using the continued fraction method with an Equation of State (EOS)
partially constrained by the recent terrestrial nuclear laboratory data. It is
shown that the density dependence of the nuclear symmetry energy
affects significantly both the frequencies and the damping
times of these modes. Besides confirming the previously found universal
behavior of the mass-scaled eigen-frequencies as functions of the compactness
of neutron stars, we explored several alternative universal scaling functions.
Moreover, the -mode is found to exist only for neutron stars having a
compactness of independent of the EOS used.Comment: Version appeared in Phys. Rev. C80, 025801 (2009
A Study of the Day - Night Effect for the Super - Kamiokande Detector: I. Time Averaged Solar Neutrino Survival Probability
This is the first of two articles aimed at providing comprehensive
predictions for the day-night (D-N) effect for the Super-Kamiokande detector in
the case of the MSW \nu_e \to \numt transition solution of the solar neutrino
problem. The one-year averaged probability of survival of the solar \nue
crossing the Earth mantle, the core, the inner 2/3 of the core, and the (core +
mantle) is calculated with high precision (better than 1%) using the elliptical
orbit approximation (EOA) to describe the Earth motion around the Sun. Results
for the survival probability in the indicated cases are obtained for a large
set of values of the MSW transition parameters and
from the ``conservative'' regions of the MSW solution,
derived by taking into account possible relatively large uncertainties in the
values of the B and Be neutrino fluxes. Our results show that the
one-year averaged D-N asymmetry in the survival probability for
neutrinos crossing the Earth core can be, in the case of , larger than the asymmetry in the probability for (only mantle
crossing + core crossing) neutrinos by a factor of up to six. The enhancement
is larger in the case of neutrinos crossing the inner 2/3 of the core. This
indicates that the Super-Kamiokande experiment might be able to test the
region of the MSW solution of the solar neutrino
problem by performing selective D-N asymmetry measurements.Comment: LaTeX2e - 18 Text Pages + 21 figures = 39 Pages. - Figures in PS +
text file sk1b14.tex requires two auxiliary files (included
Spin polarized neutron matter within the Dirac-Brueckner-Hartree-Fock approach
The relation between energy and density (known as the nuclear equation of
state) plays a major role in a variety of nuclear and astrophysical systems.
Spin and isospin asymmetries can have a dramatic impact on the equation of
state and possibly alter its stability conditions. An example is the possible
manifestation of ferromagnetic instabilities, which would indicate the
existence, at a certain density, of a spin-polarized state with lower energy
than the unpolarized one. This issue is being discussed extensively in the
literature and the conclusions are presently very model dependent. We will
report and discuss our recent progress in the study of spin-polarized neutron
matter. The approach we take is microscopic and relativistic. The calculated
neutron matter properties are derived from realistic nucleon-nucleon
interactions. This makes it possible to understand the nature of the EOS
properties in terms of specific features of the nuclear force model.Comment: 6 pages, 11 figures, revised/extended calculation
Constraining a possible time variation of the gravitational constant G with terrestrial nuclear laboratory data
Testing the constancy of the gravitational constant G has been a longstanding
fundamental question in natural science. As first suggested by Jofr\'{e},
Reisenegger and Fern\'{a}ndez [1], Dirac's hypothesis of a decreasing
gravitational constant with time due to the expansion of the Universe would
induce changes in the composition of neutron stars, causing dissipation and
internal heating. Eventually, neutron stars reach their quasi-stationary states
where cooling due to neutrino and photon emissions balances the internal
heating. The correlation of surface temperatures and radii of some old neutron
stars may thus carry useful information about the changing rate of G. Using the
density dependence of the nuclear symmetry energy constrained by recent
terrestrial laboratory data on isospin diffusion in heavy-ion reactions at
intermediate energies and the size of neutron skin in within the
gravitochemical heating formalism, we obtain an upper limit of the relative
changing rate of consistent with the
best available estimates in the literature.Comment: 27 pages, 11 figures, and 2 tables. Accepted version to appear in PRC
(2007
The solar neutrino problem after three hundred days of data at SuperKamiokande
We present an updated analysis of the solar neutrino problem in terms of both
Mikheyev-Smirnov-Wolfenstein (MSW) and vacuum neutrino oscillations, with the
inclusion of the preliminary data collected by the SuperKamiokande experiment
during 306.3 days of operation. In particular, the observed energy spectrum of
the recoil electrons from 8B neutrino scattering is discussed in detail and is
used to constrain the mass-mixing parameter space. It is shown that: 1) the
small mixing MSW solution is preferred over the large mixing one; 2) the vacuum
oscillation solutions are strongly constrained by the energy spectrum
measurement; and 3) the detection of a possible semiannual modulation of the 8B
\nu flux due to vacuum oscillations should require at least one more year of
operation of SuperKamiokande.Comment: 15 pages (RevTeX) + 8 figures (postscript). Requires epsfig.st
Recast layers on high speed steel surface after electrical discharge treatment in electrolyte
In this work are discussed some experimental data about the obtaining of recast layers on the surface of high speed tool steel after electrical discharge treatment in electrolyte. The electrical discharge treatment of steel surface in electrolyte produces a recast layer with specific combination of structure characteristics in result of nonequilibrium phase transformations. The modification goes by a high energy thermal process in electrical discharges on a very small area on the metallic surface involving melting, alloying and high speed cooling in the electrolyte. Obtained recast layers have a different structure in comparison with the metal matrix and are with higher hardness, wear- and corrosion resistance
Common Origin for the Solar and Atmospheric Neutrino Deficits
Some typos corrected, slightly different abstract, same plots, results and
conclusions.Comment: 14 Latex pages, 3 figures attached as postscript files, IFP-472-UNC,
PRL-TH-93/1
Imprints of Nuclear Symmetry Energy on Properties of Neutron Stars
Significant progress has been made in recent years in constraining the
density dependence of nuclear symmetry energy using terrestrial nuclear
laboratory data. Around and below the nuclear matter saturation density, the
experimental constraints start to merge in a relatively narrow region. At
supra-saturation densities, there are, however, still large uncertainties.
After summarizing the latest experimental constraints on the density dependence
of nuclear symmetry energy, we highlight a few recent studies examining
imprints of nuclear symmetry energy on the binding energy, energy release
during hadron-quark phase transitions as well as the -mode frequency and
damping time of gravitational wave emission of neutron stars.Comment: 10 pages. Invited talk given in the Nuclear Astrophysics session of
INPC2010, July 4-9, 2010, Vancouver, Canada; Journal of Physics: Conference
Series (2011
Neutron star properties and the equation of state of neutron-rich matter
We calculate total masses and radii of neutron stars (NS) for pure neutron
matter and nuclear matter in beta-equilibrium. We apply a relativistic nuclear
matter equation of state (EOS) derived from Dirac-Brueckner-Hartree-Fock (DBHF)
calculations. We use realistic nucleon-nucleon (NN) interactions defined in the
framework of the meson exchange potential models. Our results are compared with
other theoretical predictions and recent observational data. Suggestions for
further study are discussed.Comment: 13 pages, 9 figures, 1 table; Revised version, accepted for
publication in Physical Review
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