689 research outputs found
Radiating Shear-Free Gravitational Collapse with Charge
We present a new shear free model for the gravitational collapse of a
spherically symmetric charged body. We propose a dissipative contraction with
radiation emitted outwards. The Einstein field equations, using the junction
conditions and an ansatz, are integrated numerically. A check of the energy
conditions is also performed. We obtain that the charge delays the black hole
formation and it can even halt the collapse.Comment: 22 pages, 9 figures. It has been corrected several typos and included
several references. Accepted for publication in GR
Plasma membrane H+-ATPase in sorghum roots as affected by potassium deficiency and nitrogen sources.
Space-time inhomogeneity, anisotropy and gravitational collapse
We investigate the evolution of non-adiabatic collapse of a shear-free
spherically symmetric stellar configuration with anisotropic stresses
accompanied with radial heat flux. The collapse begins from a curvature
singularity with infinite mass and size on an inhomogeneous space-time
background. The collapse is found to proceed without formation of an even
horizon to singularity when the collapsing configuration radiates all its mass
energy. The impact of inhomogeneity on various parameters of the collapsing
stellar configuration is examined in some specific space-time backgrounds.Comment: To appear in Gen. Relativ. Gra
Nonadiabatic charged spherical gravitational collapse
We present a complete set of the equations and matching conditions required
for the description of physically meaningful charged, dissipative, spherically
symmetric gravitational collapse with shear. Dissipation is described with both
free-streaming and diffusion approximations. The effects of viscosity are also
taken into account. The roles of different terms in the dynamical equation are
analyzed in detail. The dynamical equation is coupled to a causal transport
equation in the context of Israel-Stewart theory. The decrease of the inertial
mass density of the fluid, by a factor which depends on its internal
thermodynamic state, is reobtained, with the viscosity terms included. In
accordance with the equivalence principle, the same decrease factor is obtained
for the gravitational force term. The effect of the electric charge on the
relation between the Weyl tensor and the inhomogeneity of energy density is
discussed.Comment: 23 pages, Latex. To appear in Phys. Rev. D. Some references correcte
Nature of singularity formed by the gravitational collapse in Husain space-time with electromagnetic field and scalar field
In this work, we have investigated the outcome of gravitational collapse in
Husain space-time in the presence of electro-magnetic and a scalar field with
potential. In order to study the nature of the singularity, global behavior of
radial null geodesics have been taken into account. The nature of singularities
formed has been thoroughly studied for all possible variations of the
parameters. These choices of parameters has been presented in tabular form in
various dimensions. It is seen that irrespective of whatever values of the
parameters chosen, the collapse always results in a naked singularity in all
dimensions. There is less possibility of formation of a black hole. Hence this
work is a significant counterexample of the cosmic censorship hypothesis.Comment: 9 pages, 19 figure
Diagnosis and treatment of pulmonary embolism: a multidisciplinary approach
The diagnosis of pulmonary embolism (PE) is frequently considered in patients presenting to the emergency department or when hospitalized. Although early treatment is highly effective, PE is underdiagnosed and, therefore, the disease remains a major health problem. Since symptoms and signs are non specific and the consequences of anticoagulant treatment are considerable, objective tests to either establish or refute the diagnosis have become a standard of care. Diagnostic strategy should be based on clinical evaluation of the probability of PE. The accuracy of diagnostic tests for PE are high when the results are concordant with the clinical assessment. Additional testing is necessary when the test results are inconsistent with clinical probability. The present review article represents the consensus-based recommendations of the Interdisciplinary Association for Research in Lung Disease (AIMAR) multidisciplinary Task Force for diagnosis and treatment of PE. The aim of this review is to provide clinicians a practical diagnostic and therapeutic management approach using evidence from the literature. © 2013 Lavorini et al
A espiritualidade conjugal segundo o pensamento do Pe. Henri Caffarel
A espiritualidade conjugal como caminho de santificação dos casais cristãos foi a pedra angular do pensamento do sacerdote francês Henri Caffarel ao conceber o Movimento das Equipes de Nossa Senhora (ENS). Tinha como objetivo solidificar a relação entre os cônjuges e seus familiares e contribuir com os casais para a busca da santidade conjugal. O desejo inspirador consistiu em proporcionar ao casal a possibilidade de converter a sua vida matrimonial, num verdadeiro estilo cristão de viver este sacramento no cotidiano, integrando a espiritualidade às tarefas humanas e da vida de igreja. A proposta, aos casais unidos pelo matrimônio, foi de vivenciarem uma sexualidade casta, agradável a Deus, sem, contudo, afastarem a nobreza do prazer do ato conjugal. Esposo e esposa, pela espiritualidade conjugal e com auxílio de instrumentos eficazes, seriam capacitados para gerar um itinerário do amor, da felicidade e da santidade em suas vidas, tendo na abnegação o fio condutor desta caminhada
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