186 research outputs found
Physics Potential of SPS Upgrade in regard to Beta/EC Beams
The goal for future neutrino facilities is the determination of the
mixing and CP violation in neutrino oscillations. This will require
precision experiments with a very intense neutrino source. With this objective
the creation of neutrino beams from the radioactive decay of boosted ions by
the SPS of CERN from either beta or electron capture transitions has been
propossed. We discuss the capabilities of such facilities as a function of the
energy of the boost and the baseline for the detector. We conclude that the SPS
upgrade to 1000 GeV is crucial to have a better sensitivity to CP violation if
it is accompanied by a longer baseline. We compare the physics potential for
two different configurations. In the case of beta beams, with the same boost
for both (neutrinos) and (antineutrinos), the two setups
are: I) , L=130 Km (Frejus); II) , L=650 Km (Canfranc).
In the case of monochromatic EC beams we exploit the energy dependence of
neutrino oscillations to separate out the two parameters and the CP
phase . Setup I runs at and (maximum
achievable at present SPS) to Frejus, whereas Setup II runs at and
(maximum achievable at upgraded SPS) to Canfranc. The main
conclusion is that, whereas the gain in the determination of is rather
modest, setup II provides much better sensitivity to CP violation.Comment: 6 pages, 10 figures, Proceedings of LHC LUMI 2006 CARE-HHH-AP
Wokshop, October 2006, Valenci
Extended evolution equations for neutrino propagation in astrophysical and cosmological environments
We derive the evolution equations for a system of neutrinos interacting among
themselves and with a matter background, based upon the
Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy. This theoretical
framework gives an (unclosed) set of first-order coupled integro-differential
equations governing the evolution of the reduced density matrices. By employing
the hierarchy, we first rederive the mean-field evolution equations for the
neutrino one-body density matrix associated with a system of neutrinos and
antineutrinos interacting with matter and with an anisotropic neutrino
background. Then, we derive extended evolution equations to determine neutrino
flavor conversion beyond the commonly used mean-field approximation. To this
aim we include neutrino-antineutrino pairing correlations to the two-body
density matrix. The inclusion of these new contributions leads to an extended
evolution equation for the normal neutrino density and to an equation for the
abnormal one involving the pairing mean-field. We discuss the possible impact
of neutrino-antineutrino correlations on neutrino flavor conversion in the
astrophysical and cosmological environments, and possibly upon the supernova
dynamics. Our results can be easily generalized to an arbitrary number of
neutrino families.Comment: 19 pages, 3 figures, minor corrections, references adde
Cosmological Constant and Local Gravity
We discuss the linearization of Einstein equations in the presence of a
cosmological constant, by expanding the solution for the metric around a flat
Minkowski space-time. We demonstrate that one can find consistent solutions to
the linearized set of equations for the metric perturbations, in the Lorentz
gauge, which are not spherically symmetric, but they rather exhibit a
cylindrical symmetry. We find that the components of the gravitational field
satisfying the appropriate Poisson equations have the property of ensuring that
a scalar potential can be constructed, in which both contributions, from
ordinary matter and , are attractive. In addition, there is a
novel tensor potential, induced by the pressure density, in which the effect of
the cosmological constant is repulsive. We also linearize the Schwarzschild-de
Sitter exact solution of Einstein's equations (due to a generalization of
Birkhoff's theorem) in the domain between the two horizons. We manage to
transform it first to a gauge in which the 3-space metric is conformally flat
and, then, make an additional coordinate transformation leading to the Lorentz
gauge conditions. We compare our non-spherically symmetric solution with the
linearized Schwarzschild-de Sitter metric, when the latter is transformed to
the Lorentz gauge, and we find agreement. The resulting metric, however, does
not acquire a proper Newtonian form in terms of the unique scalar potential
that solves the corresponding Poisson equation. Nevertheless, our solution is
stable, in the sense that the physical energy density is positive.Comment: 7 pages revtex, no figures; discussion on light bending added, no
effect on conclusions, version to appear in Physical Review D
Search for new physics with neutrinos at Radioactive Ion Beam facilities
We propose applications of Radioactive Ion Beam facilities to investigate
physics beyond the Standard Model. In particular, we focus on the possible
measurement of coherent neutrino-nucleus scattering and on a search for sterile
neutrinos, by means of a low energy beta-beam with a Lorentz boost factor
. In the considered setup the collected radioactive ions are
sent inside a 4 detector. For the first application we provide the number
of events associated with neutrino-nucleus coherent scattering, when the
detector is filled in with a noble liquid. For the sterile search we consider
that the spherical detector is filled in with a liquid scintillator, and that
the neutrino detection channel is inverse-beta decay. We provide the exclusion
curves for the sterile neutrino mixing parameters, based upon the 3+1
formalism, depending upon the achievable ion intensity. Our results are
obtained both from total rates, and including spectral information with binning
in energy and in distance. The proposed experiment represents a possible
alternative to clarify the current anomalies observed in neutrino experiments.Comment: 9 pages, 6 figures. v2 - added 2 figure
ANTIOXIDANT AND TOXICITY ACTIVITY IN VITRO OF TWELVE SAFROLE DERIVATIVES
Indexación: Web of Science; Scielo.The aim of this study was to determine the influence of substituents in aromatic ring and the side chain of safrole on the antioxidant capacity and toxicity of twelve synthetic derivatives of safrole (S1-S12). Each compound was analyzed by two antioxidant methods: DPPH and bleaching of β-carotene (DBC). Among the derivates of safrol assayed, S5, S6, S9, S10 and S11 showed the strongest antioxidant capacity: DPPH method, first order specific rate constant (0.0152, 0.0211, 0.0432, 0.0317 and 0.0072) and DBC (22.41 ± 0.13%, 10.71 ± 0.05 %, 9.12 ± 0.89 %, 30.97 ± 0.92 % and 19.08 ± 0.31 %), respectively. The toxicity of the active compounds was evaluated by means of two techniques, Artemia salina, LD50 (4466 ± 1057 ppm, 630 ± 108 ppm, 1513 ± 797 ppm, 1585 ± 317 ppm, 1259 ± 242 ppm) and red cells, Haemolysis (1.58 ± 0.98%, 4.02 ± 2.03%, 8.42 ± 1.38%, 2.59 ± 2.31%, 2.92 ± 0.52%), to provide preliminary information that can be used as a basis for further studies to contribute to the search for new antioxidants.http://ref.scielo.org/9sqp8
Percepción sobre Isigni de la comunidad de Sawa, Waspam, río Coco
This research describes the perception the Sawa community has about Isigni. It was a qualitative study based with a life history design that was achieve through the application of interviews and focus groups with healers, sukias, community leaders and community elders. The results of the investigation determine that in the community of Sawa the healing practices they inherited from their ancestors are still alive, they have the knowledge to identify the evil and solve the health problem that is cause by the Isigni. Therefore, the study concludes by stating that the healing of this disease consists in the application of medicinal plants, oratories and other types of healing rituals.Esta investigación describe la percepción sobre Isigni de la comunidad de Sawa. Fue un estudio cualitativo con un diseño de historia de vida donde se suministró una entrevista a curanderos, sukias, líderes comunales, ancianos y ancianas de la comunidad, así como grupos focales a estos mismos actores de la comunidad. Los resultados de la investigación determinan que en la comunidad de Sawa se mantienen viva las prácticas de sanación heredado de sus antepasados, tienen el conocimiento de identificar el mal y resolver el problema de salud que provoca el Isigni. Se concluye que la sanación a esta enfermedad consiste en la aplicación de plantas medicinales, oratorias y otros tipos de rituales de sanación
Gesti?n de liderazgo pedag?gico y ense?anza ? aprendizaje de docentes I.E ?Artemio del Solar Icochea ?, 2016
El presente informe de tesis titulado ?Gesti?n de liderazgo pedag?gico y ense?anza ? aprendizaje de docentes. I.E ?Artemio del Solar Icochea?, 2016, la misma que plante? como objetivo fundamental establecer la relaci?n de la gesti?n del liderazgo pedag?gico en los procesos de ense?anza-aprendizaje de educaci?n primaria en la instituci?n educativa objeto de estudio. Para ello se trabaj? con un dise?o de investigaci?n de tipo descriptivo ? correlacional y la poblaci?n muestral estuvo constitu?da por 3 miembros del personal directivo y 22 docentes del nivel primaria, a los mismos que se le aplicaron como herramientas de recojo de informaci?n la ficha de monitoreo de una sesi?n de aprendizaje y el cuestionario para medir el nivel de gesti?n en liderazgo pedag?gico. Entre tanto se procesaron los datos obtenidos, los mismo que arrojaron que existe un nivel moderado en la correlaci?n r de Pearson entre el nivel de gesti?n de liderazgo pedag?gico y la ense?anza ? aprendizaje de los docentes significativo al 1% (0.004) muy inferior a 0,01; con lo que se puede postular que es una correlaci?n positiva moderada, es decir que el aumento de una variable se relaciona de manera proporcional con la otraTesi
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