269,071 research outputs found
Discrete and finite Genral Relativity
We develop the General Theory of Relativity in a formalism with extended
causality that describes physical interaction through discrete, transversal and
localized pointlike fields. The homogeneous field equations are then solved for
a finite, singularity-free, point-like field that we associate to a ``classical
graviton". The standard Einstein's continuous formalism is retrieved by means
of an averaging process, and its continuous solutions are determined by the
chosen imposed symetry. The Schwarzschild metric is obtained by the imposition
of spherical symmetry on the averaged field.Comment: Modified conform the version to appear in Classical and Quantum
Gravit
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The development of a scale of the Guttman Type for the assessment of mobility disability in multiple sclerosis
Objective: The aim of the study was to develop a valid and reliable unidimensional scale of the Guttman type for the assessment of mobility disability in multiple sclerosis (MS).
Subjects: Sixty-eight subjects with a definite diagnosis of MS participated.They were attending as outpatients at a MS unit at a District General Hospital. Thirty had the primary progressive pattern of disease, and 38 had the relapsing-remitting pattern.
Methods: Formal assessments used for neurological disability were inspected, and 14 test items of gross motor function were extracted and ordered according to two criteria. These were that actions progressed from lying, to sitting, to standing and walking tasks, and that they progressed from broader to narrower bases of support. All subjects carried out all test items which were scored as ‘pass’ or ‘fail’.
Analysis: Data were tested for internal consistency, reliability, inter item correlation, reproducibility and scalability. On the basis of the results, the items were re-ordered in rank, and reduced to eleven tests. The eleven item scale was re-analysed.
Results: Results showed that the scale had an internal consistency of 0.88 (alpha coefficient) and a coefficient of reproducibility (CR) of 0.95 and above for both MS subject groups. The coefficient of scalability (CS) for items was 0.78 for primary progressive subjects and 0.74 for the relapsing-remitting group. Reliability ranged from good (kappa = 0.49) for one item, to perfect for six items.
Conclusion: The scale was demonstrated to be a hierarchical scale of the Guttman type exhibiting homogeneous unidimensionality and good reliability. The high CR indicated that scores may be summed, and the very acceptable levels of CS indicated that the cumulative scores are meaningful within the defined concept of hierarchy used in this study
Existential angst: a reading of Saul Bellow's Seize the Day
TCC (graduação) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Curso de Graduação em Língua e Literatura Estrangeira.RESUMO: Existencialismo é uma doutrina filosófica focada no ser humano em face da realidade, que vem atraindo muitos escritores há décadas. Muitos estudiosos vêm discutindo a possibilidade de Saul Bellow poder ser considerado um escritor Existencialista. A presente pesquisa analisa o livro do autor Estadunidense Seize the Day através de uma revisão bibliográfica. Aplicando os pressupostos defendidos por Jean-Paul Sartre ao livro foi possível encontrar conexões com o que defende o pensador Francês, embora falte certa densidade ao livro de Bellow quando comparado aos de outros trabalhos Existencialistas.ABSTRACT: Existentialism is a philophical doctrine focused on the human being inface of reality that has been attracting many writers for decades. Many scholars have been discussing the Existentialism in Saul Bellow's production. This work analysis the American author's novel Seize the Day through a bibliographical review. Applying presupposes defended by Jean-Paul Sartre to the novel it was possible to find connections with the French thinker's ideas though the novel lacks some density when compared to other Existentialist works
Vortex configurations and metastability in mesoscopic superconductors
The vortex dynamics in mesoscopic superconducting cylinders with rectangular
cross section under an axially applied magnetic field is investigated in the
multivortex London regime. The rectangles considered range from a square up to
an infinite slab. The flux distribution and total flux carried by a vortex
placed in an arbitrary position of the sample is calculated analytically by
assuming Clem's solution for the vortex core. The Bean-Livingston energy
barrier is also analytically calculated in this framework. A Langevin algorithm
simulates the flux penetration and dynamical evolution of the vortices as the
external field is slowly cycled. The simulated magnetization process is
governed by metastable states. The magnetization curves are hysteretic, with
paramagnetic response in part of the downward branch, and present a series of
peaks corresponding to the entry or expulsion of a single vortex. For elongated
rectangles, the vortices arrange themselves into parallel vortex chains and an
additional modulation of the magnetization, corresponding to creation or
destruction of a vortex chain, comes out.Comment: 7 pages, 4 figures. Presented on the III European Conference on
Vortex Matter in Superconductors, Crete, 2003. To appear in Physica
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