5,523 research outputs found
Forms on Vector Bundles Over Compact Real Hyperbolic Manifolds
We study gauge theories based on abelian forms on real compact
hyperbolic manifolds. The tensor kernel trace formula and the spectral
functions associated with free generalized gauge fields are analyzed.Comment: Int. Journ. Modern Physics A, vol. 18 (2003), 2041-205
On Useful Conformal Tranformations In General Relativity
Local conformal transformations are known as a useful tool in various
applications of the gravitational theory, especially in cosmology. We describe
some new aspects of these transformations, in particular using them for
derivation of Einstein equations for the cosmological and Schwarzschild
metrics. Furthermore, the conformal transformation is applied for the
dimensional reduction of the Gauss-Bonnet topological invariant in to the
spaces of lower dimensions.Comment: 17 pages, LaTeX. The paper is intended mainly for pedagogical
purposes and represents a collection of exercises concerning local conformal
transformations and dimensional reduction. To be published in "Gravitation
and Cosmology
Processo agroindustrial: obtenção de embutido fermentado tipo salame de carne de caprinos.
Preparação da matéria-prima; Preparação da massa; Embutimento; Maturação e secagem; Embalagem/estocagem.bitstream/CNPAT-2010/11961/1/Ct-074.pd
Avaliação hematológica da tilápia do Nilo (Oreochromis niloticus) cultivadas em tanques rede no reservatório de Furnas/MG.
Extending the Synoptics of Things (SoT) Framework to Manage ISoS Technology Landscapes
Managing and monitoring the software and hardware artifacts of an industrial organization are fundamental efforts that can often be challenging endeavors to achieve, especially when such technological landscapes are composed of multiple heterogeneous systems. Usually, Internet of Things (IoT) devices are provided by different suppliers and may use different protocols and interfaces. Thus, the integration of these devices results in complex development and maintenance cycles. The Synoptics of Things (SoT) framework can address these problems, in conjunction with the Informatics System of Systems (ISoS) platform by promoting an open market competitive tech nology landscape for organizations. The purpose of the research presented in this paper was to extend the SoT framework in order to manage and monitor the different elements of an ISoS enabled organization, namely the ISystems (Informatics Systems), CES (Cooperation Enabled Services), and Services. We argue that the SoT framework can be essential in a supervisory control and data acquisition (SCADA) system in today’s modern web, by adopting the concept of Web Components as a standard to enable the development of custom and reusable components. We present and discuss such issues in the context of the HORUS system, an informatic system responsible for payment enforcement in fueling stations. In this system, several devices must work in coordination, such as video cameras and video recorders, which are fundamental for the retrieving of license plate images and, therefore, be continually monitored to ensure the correct functioning of the HORUS system.info:eu-repo/semantics/publishedVersio
Hysteretic Optimization For Spin Glasses
The recently proposed Hysteretic Optimization (HO) procedure is applied to
the 1D Ising spin chain with long range interactions. To study its
effectiveness, the quality of ground state energies found as a function of the
distance dependence exponent, , is assessed. It is found that the
transition from an infinite-range to a long-range interaction at
is accompanied by a sharp decrease in the performance . The transition is
signaled by a change in the scaling behavior of the average avalanche size
observed during the hysteresis process. This indicates that HO requires the
system to be infinite-range, with a high degree of interconnectivity between
variables leading to large avalanches, in order to function properly. An
analysis of the way auto-correlations evolve during the optimization procedure
confirm that the search of phase space is less efficient, with the system
becoming effectively stuck in suboptimal configurations much earlier. These
observations explain the poor performance that HO obtained for the
Edwards-Anderson spin glass on finite-dimensional lattices, and suggest that
its usefulness might be limited in many combinatorial optimization problems.Comment: 6 pages, 9 figures. To appear in JSTAT. Author website:
http://www.bgoncalves.co
Electroanalytical study of Prussian Blue modified glassy carbon paste electrodes
Two types of glassy carbon (GC) powder (i.e., Sigradur K and Sigradur G) have been mixed with mineral oil to obtain glassy carbon paste electrodes (GCPE's). The electrochemical behavior of such electrodes at different percentages of glassy carbon has been evaluated with respect to the electrochemistry of ferricyanide as revealed with cyclic voltammetry and the best paste composition was chosen. GC was then modified with Prussian Blue (PB), mixed at different percentages with unmodified GC and with a fixed amount of mineral oil in order to obtain PB modified glassy carbon paste electrodes (PB-GCPE's). PB-GCPE's with different percentages of GC modified with PB (PB-GC) were compared and the dependence on the amount of PB on their performances was evaluated by studying the parameters of cyclic voltammetry (i.e., current peak, Ep, anodic and cathodic current ratio, charge density) and the amperometric response to H2O2. Data interpretation based on the GC surface area is presented. GCPE's with a selected amount of PB-GC were then tested as H2O2 probes and all the analytical parameters together with the dependence on pH were evaluated. Some preliminary experiments with these electrodes assembled as glucose, lysine and lactate biosensors are also reported
Troubles with quantum anistropic cosmological models: Loss of unitarity
The anisotropic Bianchi I cosmological model coupled with perfect fluid is
quantized in the minisuperspace. The perfect fluid is described by using the
Schutz formalism which allows to attribute dynamical degrees of freedom to
matter. A Schr\"odinger-type equation is obtained where the matter variables
play the role of time. However, the signature of the kinetic term is
hyperbolic. This Schr\"odinger-like equation is solved and a wave packet is
constructed. The norm of the resulting wave function comes out to be time
dependent, indicating the loss of unitarity in this model. The loss of
unitarity is due to the fact that the effective Hamiltonian is hermitian but
not self-adjoint. The expectation value and the bohmian trajectories are
evaluated leading to different cosmological scenarios, what is a consequence of
the absence of a unitary quantum structure. The consistency of this quantum
model is discussed as well as the generality of the absence of unitarity in
anisotropic quantum models.Comment: Latex file, 18 pages. To appear in General Relativity and Gravitatio
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