Dark energy from scalar field with Gauss Bonnet and non-minimal kinetic coupling

We study a model of scalar field with a general non-minimal kinetic coupling to itself and to the curvature, and additional coupling to the Gauss Bonnet 4-dimensional invariant. The model presents rich cosmological dynamics and some of its solutions are analyzed. A variety of scalar fields and potentials giving rise to power-law expansion have been found. The dynamical equation of state is studied for two cases, with and without free kinetic term . In both cases phenomenologically acceptable solutions have been found. Some solutions describe essentially dark energy behavior, and and some solutions contain the decelerated and accelerated phases.Comment: 21 page

Diatoms as a paleoproductivity proxy in the NW Iberian coastal upwelling system (NE Atlantic)

The objective of the current work is to improve our understanding of how water column diatom's abundance and assemblage composition is seasonally transferred from the photic zone to seafloor sediments. To address this, we used a dataset derived from water column, sediment trap and surface sediment samples recovered in the NW Iberian coastal upwelling system. Diatom fluxes (2.2 (+/- 5.6) 10(6) valves m(-2) d(-1)) represented the majority of the siliceous microorganisms sinking out from the photic zone during all studied years and showed seasonal variability. Contrasting results between water column and sediment trap diatom abundances were found during downwelling periods, as shown by the unexpectedly high diatom export signals when diatom- derived primary production achieved their minimum levels. They were principally related to surface sediment remobilization and intense Minho and Douro river discharge that constitute an additional source of particulate matter to the inner continental shelf. In fact, contributions of allochthonous particles to the sinking material were confirmed by the significant increase of both benthic and freshwater diatoms in the sediment trap assemblage. In contrast, we found that most of the living diatom species blooming during highly productive upwelling periods were dissolved during sinking, and only those resistant to dissolution and the Chaetoceros and Leptocylindrus spp. resting spores were susceptible to being exported and buried. Fur-thermore, Chaetoceros spp. dominate during spring-early summer, when persistent northerly winds lead to the upwelling of nutrient-rich waters on the shelf, while Leptocylindrus spp. appear associated with late-summer upwelling relaxation, characterized by water column stratification and nutrient depletion. These findings evidence that the contributions of these diatom genera to the sediment's total marine diatom assemblage should allow for the reconstruction of different past upwelling regimes.CAIBEX [CTM2007-66408-C02-01/MAR]; REIMAGE [CTM2011-30155-C03-03]; Spanish Government, EXCAPA project [10MDS402013PR]; Xunta de Galicia; EU FEDER [INTERREG 2009/2011-0313/RAIA/E]; RAIA. co [INTERREG2011/2013-052/RAIA.co/1E]; CALIBERIA project [PTDC/MAR/102045/2008]; Fundacao para a Ciencia e a Tecnologia (FCT-Portugal) [COMPETE/FEDER-FCOMP01-0124-FEDER-010599]; Xunta de Galicia (Spain) [SFRH/BPD/111433/2015]; FCT (Portugal) [SFRH/BPD/111433/2015]; [SFRH/BD/88439/2012

General Non-minimal Kinetic coupling to gravity

We study a new model of scalar field with a general non-minimal kinetic coupling to itself and to the curvature, as a source of dark energy, and analyze the cosmological dynamics of this model and the issue of accelerated expansion. A wide variety of scalar fields and potentials giving rise to power-law expansion have been found. The dynamical equation of state is studied for the two cases, without and with free kinetic term . In the first case, a behavior very close to that of the cosmological constant was found. In the second case, a solution was found, which match the current phenomenology of the dark energy. The model shows a rich variety of dynamical scenarios.Comment: 25 pages, 3 figures; figure added, references adde

Diseño del sistema de ohsas para una empresa procesadora de alimentos

El objetivo principal de este trabajo es diagnosticar la situación actual de la empresa en materia de seguridad salud y medio ambiente, proponer un plan de mejoras que permita cumplir con las disposiciones de los reguladores y evitar danos a la salud de los colaboradores, a los bienes de la empresa y al medio ambiente. Para la consecución de este documento se realizo un trabajo de campo para observar las instalaciones y el proceso productivo, con el propósito de tomar notas para identificar debilidades en el proceso de gestión de seguridad saludad y medio ambiente llevado por la empresa. Parte del trabajo de escritorio fue solicitar la documentación soporte con que cuenta la empresa, para luego compararlo con las normas y reglamento que regulan la seguridad industrial y salud en el país. Para la elaboración del diagnostico utilizamos varias técnicas tales como: El análisis de tarea (AST) Análisis de riesgo de la tarea (ART) Análisis históricos de los accidentes, panorama de riesgo mapeos y las normas OHSAS 18001. Los problemas encontrados son la falta de una política de seguridad y salud, falta de objetivos departamentales en materia de seguridad y salud, incumplimiento de los requisitos legales y otros, falta de procedimientos, falta de control de la documentación del sistema de gestión, falta de un plan de capacitación basado en un diagnostico de necesidades, falta de un proceso de auditoria del sistema de gestión que permita identificar las debilidades del sistema y emprender la mejora continua. La auditoria del programa actual de gestión en seguridad y salud, se efectúo basado en la norma OHSAS 18001 : 1999, la cual permitió presentar una propuesta que cumpla con los compromisos adquiridos con sus colaboradores y con las disposiciones de los cuerpos legales que regulan la seguridad y la salud en el país y a su vez le otorgue a la gestión de seguridad y salud el carácter de sistema, para conseguir que la actividad sea sostenible. Las conclusiones y recomendaciones expuestas en el documento apuntan a que todas las acciones preventivas y correctivas a tomar para mejorar el desempeño individual y colectivo en seguridad y salud, tengan su respectivo soporte que permita verificar lo actuado, para proponer la mejora continua del sistema de gestión.ESPO

5-Hy­droxy-7-phenyl-5-(prop-2-yn-1-yl)-5,6-dihydro-1-benzofuran-2(4H)-one monohydrate

In the title compound, C17H14O3·H2O, the six-membered ring, which adopts a half-chair conformation, makes a dihedral angle of 24.3 (2)° with the phenyl ring. In the crystal, the components are linked by O—H⋯O hydrogen bonds involving the water mol­ecule, and the hy­droxy and carbonyl groups of the organic compound. These inter­actions form a square-like supra­molecular synthon unit which propagates as chains parallel to the crystallographic b axis. A C—H⋯O interaction also occurs

Multimodal collaborative workgroup dataset and challenges

© 2017, CEUR-WS. All rights reserved. This work presents a multimodal dataset of 17 workgroup sessions in a collaborative learning activity. Workgroups were conformed of two or three students using a tabletop application in a co-located space. The dataset includes time-synchronized audio, video and tabletop system's logs. Some challenges were identified during the collection of the data, such as audio participation identification, and user traces identification. Future work should explore how to overcome the aforementioned difficulties

Asymmetric embedding in brane cosmology

We derive a system of cosmological equations for a braneworld with induced curvature which is a junction between several bulk spaces. The permutation symmetry of the bulk spaces is not imposed, and the values of the fundamental constants, and even the signatures of the extra dimension, may be different on different sides of the brane. We then consider the usual partial case of two asymmetric bulk spaces and derive an exact closed system of scalar equations on the brane. We apply this result to the cosmological evolution on such a brane and describe its various partial cases.Comment: 10 page