5,882 research outputs found
The Effective Lorentzian and Teleparallel Spacetimes Generated by a Free Electromagnetic Field
In this paper we show that a free electromagnetic field living in Minkowski
spacetime generates an effective Weitzenbock or an effective Lorentzian
spacetime whose properties aredetermined in details. These results are possible
because we found using the Clifford bundle formalism the noticeable result that
the energy-momentum densities of a free electromagnetic field are sources of
the Hodge duals of exact 2-form fields which satisfy Maxwell like equations.Comment: A missing term in Eq.(14) has been inserted and some misprints
correcte
A Unified Framework for Producing CAI Melting, Wark-Lovering Rims and Bowl-Shaped CAIs
Calcium Aluminium Inclusions (CAIs) formed in the Solar System, some 4,567
million years ago. CAIs are almost always surrounded by Wark-Lovering Rims
(WLRs), which are a sequence of thin, mono/bi-mineralic layers of refractory
minerals, with a total thickness in the range of 1 to 100 microns. Recently,
some CAIs have been found that have tektite-like bowl-shapes. To form such
shapes, the CAI must have travelled through a rarefied gas at hypersonic
speeds. We show how CAIs may have been ejected from the inner solar accretion
disc via the centrifugal interaction between the solar magnetosphere and the
inner disc rim. They subsequently punched through the hot, inner disc rim wall
at hypersonic speeds. This re-entry heating partially or completely evaporated
the CAIs. Such evaporation could have significantly increased the metal
abundances of the inner disc rim. High speed movement through the inner disc
produced WLRs. To match the observed thickness of WLRs required metal
abundances at the inner disc wall that are of order ten times that of standard
solar abundances. The CAIs cooled as they moved away from the protosun, the
deduced CAI cooling rates are consistent with the CAI cooling rates obtained
from experiment and observation. The speeds and gas densities required to form
bowl-shaped CAIs are also consistent with the expected speeds and gas densities
for larger, ~ 1 cm, CAIs punching through an inner accretion disc wall.Comment: 70 pages, 41 figure
Neutron diffraction of hydrogenous materials: measuring incoherent and coherent intensities separately from liquid water - a 40-year-old puzzle solved
(short version) Accurate determination of the coherent static structure
factor of disordered materials containing proton nuclei is prohibitively
difficult by neutron diffraction, due to the large incoherent cross section of
H. This notorious problem has set severe obstacles to the structure
determination of hydrogenous materials up to now, via introducing large
uncertainties into neutron diffraction data processing. Here we present the
first accurate separate measurements, using polarized neutron diffraction, of
the coherent and incoherent contributions to the total static structure factor
of 5 mixtures of light and heavy water, over an unprecedentedly wide momentum
transfer range. The structure factors of HO and DO mixtures derived in
this work may signify the beginning of a new era in the structure determination
of hydrogenous materials, using neutron diffraction.Comment: 8 page
A Maxwell Like Formulation of Gravitational Theory in Minkowski Spacetime
In this paper using the Clifford bundle formalism a Lagrangian theory of the
Yang-Mills type (with a gauge fixing term and an auto interacting term) for the
gravitational field in Minkowski spacetime is presented. It is shown how two
simple hypothesis permit the interpretation of the formalism in terms of
effective Lorentzian or teleparallel geometries. In the case of a Lorentzian
geometry interpretation of the theory the field equations are shown to be
equivalent to Einstein's equations.Comment: This is a version of a paper published in Int. J. Mod. Phs. D 16(6),
1027-1041 (2007) where some misprints and typos have been corrected, some
references have been updated, a footnote has been added and some few
sentences have been rewritten to better explain the role of the (plastic)
deformation tensor
Karen Horney\u27s Three Character Styles [Neurotic Styles] as Responses to Early Maternal Deprivation and Unmanageable Rage: Three Illustrative Case Studies
Three of my patients presented with stories of maternal abandonment as well as struggles with rage. One struggled with a vengeful rage, which highlighted deep feelings of injustice. Characterologically he moved against people. A second showed a connection between rage and frightening dissociative episodes that left her struggling with passive fantasies of death and desertion. Characterologically she moved towards people. A third patient made use of rage as a way to stay away from people. She used intimidation as a way to characterologically move away from people, and preferred to remain alone. Although each of these clients struggled with rage tied to maternal empathic failures, they differed significantly in their character style and overall adaptation in adult life. Their styles of coping with anger corresponded to the neurotic solutions described by Karen Horney (1945) moving against people, moving towards people, and moving away from people. Within the maternal bond, these individuals experienced rage as unacceptable and treatment allowed some of their experiences a voice. This study aimed to reflect on the psychodynamic treatment of rage in each Horneyean character style. This project presents three case studies exemplifying Horney\u27s theory, and contextualizing the function and meaning of rage in instances of perceived or actual maternal abandonment. Examining these cases through a Horneyean lens shows how her work anticipated contemporary psychoanalytic psychodiagnostics (i.e. The Psychodynamic Diagnostic Manual), and how valuable her work remains to theory and treatment today
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