7,907 research outputs found
Solving non-perturbative flow equations
Non-perturbative exact flow equations describe the scale dependence of the
effective average action. We present a numerical solution for an approximate
form of the flow equation for the potential in a three-dimensional N-component
scalar field theory. The critical behaviour, with associated critical
exponents, can be inferred with good accuracy.Comment: Latex, 14 pages, 2 uuencoded figure
Domain wall description of superconductivity
In the present work we shall address the issue of electrical conductivity in
superconductors in the perspective of superconducting domain wall solutions in
the realm of field theory. We take our set up made out of a dynamical complex
scalar field coupled to gauge field to be responsible for superconductivity and
an extra scalar real field that plays the role of superconducting domain walls.
The temperature of the system is interpreted through the fact that the soliton
following accelerating orbits is a Rindler observer experiencing a thermal
bath.Comment: 9 pages, 5 figures, Latex. Version to appear in PL
A call for collaboration: perception of religious and spiritual leaders on mental health (a Portuguese sample)
To assess the relationship and collaborations between mental health professionals and religious and spiritual leaders, eleven representatives of ten different religious affiliations in Portugal participated in this qualitative study. Major findings reported showed that religious leaders perceive themselves as important agents in promoting and preserving their congregants’ mental health, as well as aiding their recovery processes; however this occurs without much referral to or collaboration with mental health professionals. These findings are discussed, as well as why and how a healthy collaboration between mental health professionals and religious leaders can positively impact the psychotherapeutic relationship and clinical outcomes with religious/spiritual clients.info:eu-repo/semantics/acceptedVersio
Exciton trapping in magnetic wire structures
The lateral magnetic confinement of quasi two-dimensional excitons into wire
like structures is studied. Spin effects are take into account and two
different magnetic field profiles are considered, which experimentally can be
created by the deposition of a ferromagnetic stripe on a semiconductor quantum
well with magnetization parallel or perpendicular to the grown direction of the
well. We find that it is possible to confine excitons into one-dimensional (1D)
traps. We show that the dependence of the confinement energy on the exciton
wave vector, which is related to its free direction of motion along the wire
direction, is very small. Through the application of a background magnetic
field it is possible to move the position of the trapping region towards the
edge of the ferromagnetic stripe or even underneath the stripe. The exact
position of this 1D exciton channel depends on the strength of the background
magnetic field and on the magnetic polarisation direction of the ferromagnetic
film.Comment: 10 pages, 7 figures, to be published in J. Phys: Condens. Matte
Recomendação de adubação potássica de manutenção para a cultura da ameixeira por meio de análise foliar.
bitstream/item/31554/1/comunicado67.pd
The millisecond pulsar mass distribution: Evidence for bimodality and constraints on the maximum neutron star mass
The mass function of neutron stars (NSs) contains information about the late
evolution of massive stars, the supernova explosion mechanism, and the
equation-of-state of cold, nuclear matter beyond the nuclear saturation
density. A number of recent NS mass measurements in binary millisecond pulsar
(MSP) systems increase the fraction of massive NSs (with M)
to of the observed population. In light of these results, we
employ a Bayesian framework to revisit the MSP mass distribution. We find that
a single Gaussian model does not sufficiently describe the observed population.
We test alternative empirical models and infer that the MSP mass distribution
is strongly asymmetric. The diversity in spin and orbital properties of
high-mass NSs suggests that this is most likely not a result of the recycling
process, but rather reflects differences in the NS birth masses. The asymmetry
is best accounted for by a bimodal distribution with a low mass component
centred at M and dispersed by
M, and a high-mass component with a mean of
and a dispersion of
M. We also establish a lower limit of M
at 98% C.L. for the maximum NS mass, from the absence of a high-mass truncation
in the observed masses. Using our inferred model, we find that the measurement
of 350 MSP masses, expected after the conclusion of pulsar surveys with the
Square-Kilometre Array, can result in a precise localization of a maximum mass
up to 2.15 M, with a 5% accuracy. Finally, we identify possible
massive NSs within the known pulsar population and discuss birth masses of
MSPs.Comment: submitted to ApJ; 21 pages in aastex6 two-column format, 12 figures,
5 tables. Comments are welcom
Alguns insetos úteis ao algodoeiro.
bitstream/item/126637/1/Alguns-Insetos-uteis-ao-algoodoeiro.pd
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