2,921 research outputs found
Spatially resolving the thermally inhomogeneous outer atmosphere of the red giant Arcturus in the 2.3 micron CO lines
The outer atmosphere of K giants shows thermally inhomogeneous structures
consisting of the hot chromospheric gas and the cool molecular gas. We present
spectro-interferometric observations of the multicomponent outer atmosphere of
the well-studied K1.5 giant Arcturus (alpha Boo) in the CO first overtone lines
near 2.3 micron. We observed Arcturus with the AMBER instrument at the Very
Large Telescope Interferometer (VLTI) at 2.28--2.31 micron with a spectral
resolution of 12000 and at projected baselines of 7.3, 14.6, and 21.8 m. The
high spectral resolution of the VLTI/AMBER instrument allowed us to spatially
resolve Arcturus in the individual CO lines. Comparison of the observed
interferometric data with the MARCS photospheric model shows that the star
appears to be significantly larger than predicted by the model. It indicates
the presence of an extended component that is not accounted for by the current
photospheric models for this well-studied star. We found out that the observed
AMBER data can be explained by a model with two additional CO layers above the
photosphere. The inner CO layer is located just above the photosphere, at 1.04
+/- 0.02 stellar radii, with a temperature of 1600 +/- 400 K and a CO column
density of 10^{20 +/- 0.3} cm^-2. On the other hand, the outer CO layer is
found to be as extended as to 2.6 +/- 0.2 stellar radii with a temperature of
1800 +/- 100 K and a CO column density of 10^{19 +/- 0.15} cm^-2. The
properties of the inner CO layer are in broad agreement with those previously
inferred from the spatially unresolved spectroscopic analyses. However, our
AMBER observations have revealed that the quasi-static cool molecular component
extends out to 2--3 stellar radii, within which region the chromospheric wind
steeply accelerates.Comment: 10 pages, 9 figures, accepted for publication in Astronomy and
Astrophysic
Infinite-dimensional representations of the rotation group and Dirac's monopole problem
Within the context of infinite-dimensional representations of the rotation
group the Dirac monopole problem is studied in details. Irreducible
infinite-dimensional representations, being realized in the indefinite metric
Hilbert space, are given by linear unbounded operators in infinite-dimensional
topological spaces, supplied with a weak topology and associated weak
convergence. We argue that an arbitrary magnetic charge is allowed, and the
Dirac quantization condition can be replaced by a generalized quantization rule
yielding a new quantum number, the so-called topological spin, which is related
to the weight of the Dirac string.Comment: JHEP style. Extended version of hep-th/0403146. Revised version,
title and some notations are changed. References and Appendix B are adde
Plan de estrategias para reducción de estrés laboral intervención en una empresa de ventas
The next work is about the control of levels of stress in a sales Company. This project talks about the causes and impact of the job stress and how this it affects business development. This project uses the experimental method with a control and experimental group. In the experimental group use strategies to get a better stress level like: rational thinks, focusing, adequate sleep, business dealings, adequate eat, and relaxing exorcises. Both groups measured by OIT-OMS test. After the intervention of experimental group the results presents that P>0, 05, it shows that it does not exist a significant difference so the stress levels did not reduce.El siguiente trabajo trata sobre el manejo de los niveles de estrés en una empresa de ventas. Este proyecto habla sobre las causas y consecuencias del estrés laboral y como afectan al desarrollo empresarial. El proyecto usó el método cuasi experimental con un grupo de control y un grupo experimental. En el experimental se intervino con estrategias para mejorar los niveles de estrés como: pensamiento racional, focusing, dormir y comer adecuadamente, manejos empresariales y ejercicios de relajación. Ambos grupos se midieron por la prueba OIT-OMS. Tras la intervención del grupo experimental presenta resultados P > 0.05 mostrando que estadísticamente no existe una diferencia y por tanto no se redujeron los niveles de estrés
Could contaminant induced mutations lead to a genetic diversity overestimation?
Contaminant driven genetic erosion reported
through the inspection of selectable traits can be underestimated
using neutral markers. This divergence was previously
reported in the aquatic system of an abandoned
pyrite mine. The most sensitive genotypes of the microcrustacean
cladoceran Daphnia longispina were found to
be lacking in the impacted reservoir near the entrance of
the metal rich acid mine drainage (AMD). Since that
divergence could be, at least partially, accounted for by
mutagenicity and genotoxicity of the AMD, the present
study aimed at providing such a characterization. The
Allium cepa chromosomal aberration assay, using root
meristematic cells, was carried out, by exposing seeds to
100, 10, 1, and 0.1 % of the local AMD. Chromosomal
aberrations, cell division phases and cell death were
quantified after the AMD exposure and after 24 and 48 h
recovery periods. The AMD revealed to be mutagenic and
genotoxic, even after diluting it to 1 and 0.1 %. Dilutions
within this range were previously found to be below the
lethality threshold and to elicit sublethal effects on reproduction
of locally collected D. longispina clonal lineages
Significant mutagenic effects (micronuclei and chromosomal
breaks) were also found at 0.1 % AMD, supporting
that exposure may induce permanent genetic alterations.
Recovery tests showed that AMD genotoxic effects persisted
after the exposure.This study was partially was funded by FSE and
POPH by national funds through Fundação para a Ciência e a
Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior
(Ph.D. Grant SFRH/BD/28526/2006 to Olímpia Sobral)
Three-dimensional hydrodynamic and sediment transport modeling to test the sediment focusing hypothesis in upland lakes
Palaeolimnological studies rely on assumptions regarding the distribution and completeness of lake deposits that are not always fully supported by observations. In particular, the assumption that “focusing” of suspended sediments leads to preferential deposition in the deepest part of a lake is not always justified, especially in upland lakes subject to energetic wind forcing. Few studies have investigated the hydrodynamic controls on lake sediment focusing, especially the importance of wind-driven currents in deep water. We combine a three-dimensional numerical hydrodynamic and suspended sediment model (FVCOM) with a semi-empirical wind wave model to investigate the potential mobility of bottom sediments in a small oligotrophic upland lake (Llyn Conwy, north Wales, UK). Exploratory simulations of wave- and current-generated bottom stress and suspended sediment dynamics confirm the expected importance of wave-generated bottom stresses in shallower waters (< 3 m depth) around the shore. Field survey shows that lake sediments are largely absent from this zone. This is consistent with peripheral wave action as a sediment focusing mechanism. In deeper water, wind-driven currents become the dominant contributor to bottom stress. Strong wind forcing events drive an energetic circulation with peak bottom stresses that intermittently exceed any realistic erosion threshold over a large proportion of the lake at depths far below those at which waves can be effective. The spatial distribution of lake sediments, and the completeness of the sediment record, is thus determined by a complex interaction between wind-driven circulation and bathymetry, rather than by bathymetry alone. Although our sediment dynamics simulations are purely exploratory, the results are consisted with survey results that show a patchy distribution of deep-water accumulation. Some implications of these results for the selection of sediment coring locations and the interpretation of sediment records are considered
Recomendaciones tentativas de fertilizantes y cal para diversos cultivos de acuerdo con los resultados de los análisis de suelos. Primera aproximación.
Presenta un panorama sobre la fertilidad general de los suelos del país. En cuanto a N, indica que la respuesta está principalmente concentrada en las regiones más bajas y cálidas del país. Las respuestas al P han estado principalmente localizadas en las regiones e intermedias. Con excepción de los llanos donde se encuentran suelos extremadamente deficientes en P. En las zonas frías del país, el P es el primer elemento claramente limitante. Las respuestas al K, por la investigación en el ICA han sido relativamente raras. Las únicas respuestas significativas han obtenido en la Sub-estación La Selva, Antioquia y sobre un suelo latosólico en Tulio Ospina. Es bastante común encontrar poca respuesta inicial al K. En cuanto a B, Mo y Zn, se han obtenido respuestas notables de alfalfa a la aplicación de B. En el Valle del Cauca es un fracaso la siembra de alfalfa si no se añade B. El suelo rojo de Antioquia en invernadero ha respondido al Mo. En el Valle del Cauca se han observado síntomas de deficiencia de Zn en máiz. Los objetivos de los análisis de suelos son: usar los análisis para hacer recomendaciones de fertilizantes y cal, discutir algunos factores que afectan las recomendaciones. Se presentan tablas con límites de valores bajo, medio y alto para P y K en varios cultivo
Plan de negocios para la creación de un restaurante de pasta cien porciento artesanal ubicado en la localidad de Engativá de la ciudad de Bogotá
Este documento se estructuro en cuatro capítulos donde se desarrollan los siguientes temas de estudio: Primero, el estudio de mercados presenta el análisis del entorno del sector de restaurantes en Colombia, la competencia directa e indirecta, la identificación del producto y las estrategias que se aplicaran. Segundo, el estudio de técnico muestra las variables que inciden el tamaño del negocio, en la localización, también se dan a conocer los procesos técnicos de elaboración y comercialización de las pastas artesanales, la capacidad instalada y la distribución de la planta. Tercero, el estudio administrativo y jurídico-legal lo conforma el direccionamiento estratégico, la definición de áreas y perfiles de cargo, políticas de desarrollo, seguridad e higiene industrial y el marco jurídico legal que rige a este tipo de microempresas. Cuarto, el estudio financiero se estima cual es la inversión del proyecto, las proyecciones de venta, los presupuestos de costos y gastos, el estados de resultados, flujo de caja, balance general y el análisis de los estados financieros con su respectiva interpretación. Y por último, las conclusione
Plan de negocios para la creación de un restaurante de pasta cien porciento artesanal ubicado en la localidad de Engativá de la ciudad de Bogotá
Este documento se estructuro en cuatro capítulos donde se desarrollan los siguientes temas de estudio: Primero, el estudio de mercados presenta el análisis del entorno del sector de restaurantes en Colombia, la competencia directa e indirecta, la identificación del producto y las estrategias que se aplicaran. Segundo, el estudio de técnico muestra las variables que inciden el tamaño del negocio, en la localización, también se dan a conocer los procesos técnicos de elaboración y comercialización de las pastas artesanales, la capacidad instalada y la distribución de la planta. Tercero, el estudio administrativo y jurídico-legal lo conforma el direccionamiento estratégico, la definición de áreas y perfiles de cargo, políticas de desarrollo, seguridad e higiene industrial y el marco jurídico legal que rige a este tipo de microempresas. Cuarto, el estudio financiero se estima cual es la inversión del proyecto, las proyecciones de venta, los presupuestos de costos y gastos, el estados de resultados, flujo de caja, balance general y el análisis de los estados financieros con su respectiva interpretación. Y por último, las conclusione
Analysis of the Credit Activity of the Popular and Solidarity Financial Sector of Ecuador
The objective of this article was to analyze the credit activity of the Popular and Solidarity Financial Sector of Ecuador in the first five-month period of 2021, according to the data generated by the Superintendency of Popular and Solidarity Economy with cuts to the months of January, February, March, April, and May of the same year. The figures of the loan portfolio by the segment of the popular and solidarity financial sector, by economic activity, as well as the distribution of the loan portfolio by segment, type of credit, sex, age range, and level of education were identified and analyzed, which made it possible to know the performance of the credit portfolio in this sector during the time analyzed.
Keywords: popular and solidarity financial sector, credit portfolio, economic activity.
Resumen
Este artículo tuvo como objetivo analizar la actividad crediticia del Sector Financiero Popular y Solidario del Ecuador del primer quinquemestre del año 2021, según los datos generados por la Superintendencia de Economía Popular y Solidaria con corte a los meses de enero, febrero, marzo, abril y mayo del mismo año. Se identificaron y analizaron las cifras de la cartera de crédito por segmento del sector financiero popular y solidario, por actividad económica, así como la distribución de la cartera de crédito por segmento, por tipo de crédito, por sexo, rango etario y nivel de instrucción, lo que permitió conocer el desempeño de la cartera de crédito de este sector del tiempo analizado.
Palabras Clave: sector financiero popular y solidario, cartera de crédito, actividad económica
Intuitionistic S4 is decidable
In this paper we demonstrate decidability for the intuitionistic modal logic
S4 first formulated by Fischer Servi. This solves a problem that has been open
for almost thirty years since it had been posed in Simpson's PhD thesis in
1994. We obtain this result by performing proof search in a labelled deductive
system that, instead of using only one binary relation on the labels, employs
two: one corresponding to the accessibility relation of modal logic and the
other corresponding to the order relation of intuitionistic Kripke frames. Our
search algorithm outputs either a proof or a finite counter-model, thus,
additionally establishing the finite model property for intuitionistic S4,
which has been another long-standing open problem in the area.Comment: 13 pages conference paper + 26 pages appendix with examples and
proof
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