CMB and matter power spectra with non-linear dark-sector interactions

An interaction between dark matter and dark energy, proportional to the product of their energy densities, results in a scaling behavior of the ratio of these densities with respect to the scale factor of the Robertson-Walker metric. This gives rise to a class of cosmological models which deviate from the standard model in an analytically tractable way. In particular, it becomes possible to quantify the role of potential dark-energy perturbations. We investigate the impact of this interaction on the structure formation process. Using the (modified) CAMB code we obtain the CMB spectrum as well as the linear matter power spectrum. It is shown that the strong degeneracy in the parameter space present in the background analysis is considerably reduced by considering \textit{Planck} data. Our analysis is compatible with the $\Lambda$CDM model at the $2\sigma$ confidence level with a slightly preferred direction of the energy flow from dark matter to dark energy.Comment: 22 pages, 8 figures, analysis enlarged, comments and references added, accepted for publication in JCA

Viscous dark fluid Universe: a unified model of the dark sector?

The Universe is modeled as consisting of pressureless baryonic matter and a bulk viscous fluid which is supposed to represent a unified description of the dark sector. In the homogeneous and isotropic background the \textit{total} energy density of this mixture behaves as a generalized Chaplygin gas. The perturbations of this energy density are intrinsically nonadiabatic and source relative entropy perturbations. The resulting baryonic matter power spectrum is shown to be compatible with the 2dFGRS and SDSS (DR7) data. A joint statistical analysis, using also Hubble-function and supernovae Ia data, shows that, different from other studies, there exists a maximum in the probability distribution for a negative present value of the deceleration parameter. Moreover, the unified model presented here favors a matter content that is of the order of the baryonic matter abundance suggested by big-bang nucleosynthesis. A problem of simple bulk viscous models, however, is the behavior of the gravitational potential and the reproduction of the CMB power spectrum.Comment: 12 pages, 3 figures, contributed paper to 8th Friedmann Seminar, 30 May to 3 June 2011, Rio de Janeiro, Brazi

Roman situlae from Conimbriga (Portugal): Compositional and microstructural characterization of anthropomorphic handle attachments

info:eu-repo/semantics/publishedVersio

Recursos em areias e cascalhos ao largo da ilha de S. Miguel, Açores

A campanha de geofísica SAMI-1 realizada ao largo da Ilha de S. Miguel (Açores) permitiu a aquisição de perfis sísmicos de alta resolução (Boomer) e de batimetria detalhada. Estes dados possibilitaram a definição das áreas mais promissoras em inertes (areias e cascalhos) na plataforma insular de S. Miguel. Deverão ser efectuados estudos de pormenor de forma a caracterizar estas áreas, para servirem de apoio à elaboração de um plano de gestão da extracção de inertes em redor das ilhas

End-users’ perspectives of an eHealth platform to promote physical activity in COPD: a qualitative study

Introduction: eHealth platforms can be used as a tool to promote physical activity (PA) in patients with COPD. When developing such platforms, a bottom-up approach is needed to ensure that patients’ and healthcare professionals’ (HCP) needs and expectations are addressed. Aim: To assess patients’ and HCP’ perspectives on the ideal eHealth platform (web application - app - for HCP + mobile app for patients) for PA promotion in patients with COPD. Methods: One focus group with 5 patients (68±8 yrs, FEV1 44±21pp) and 6 individual interviews with HCP (physicians and physiotherapist, 39±10 yrs) were conducted using a semi-structured interview guide. Interviews were recorded and transcripts were analysed using the Grounded Theory approach. Results: Participants considered an eHealth platform to promote patients' PA valuable. Both groups suggested that PA should be individualised according to patients’ characteristics. The main features for a mobile app included: shared goal setting, PA progress graphs, motivational messages and goal badges, notifications, a bi-directional communication system to support patients and information on breathing exercises. Both groups highlighted the importance of measuring steps, PA duration, SpO2, and dyspnoea on exertion. For the web app, the HCP highlighted the importance of a notification system to signal PA changes or non-compliance (e.g., colour scheme), as well as tabs for PA goal setting and monitoring. HCP recommended this platform for patients with stable or mild disease and/or those attending pulmonary rehabilitation. Conclusion: Findings provide guidance to the design of future eHealth platforms for PA promotion in COPD.publishe

Eficiência agronômica do inoculante de cana-de-açúcar aplicado em três ensaios conduzidos no Estado do Rio de Janeiro durante o primeiro ano de cultivo.

A inoculação de cana-de-açúcar utilizando bactérias diazotróficas selecionadas pode reduzir a demanda de nitrogênio fertilizante na cultura. O objetivo deste trabalho foi testar o inoculante contendo uma mistura de cinco espécies de bactérias diazotróficas em duas variedades de cana-de-açúcar, RB72454 e RB867515, plantadas em três locais sendo duas usinas produtoras de açúcar do Estado Rio de Janeiro e o terceiro no Campo Experimental da Embrapa Agrobiologia. No primeiro ano de plantio no campo, apenas a variedade RB867515 respondeu a inoculação utilizando a mistura de estirpes.bitstream/item/42983/1/BOP-45.pd

Evaluación de las propiedades del subsuelo de Badajoz (España) con fines constructivos mediante Sistemas de Información Geográfica

Subsoil properties study is crucial in order to design foundations and to prevent structural pathologies. In this paper, 459 explorations of Badajoz subsoil were analyzed; they were carried out during two decades. A bank of data creation was described, as well as the elaboration of a set of maps. They constitute the Basic Geotechnical Map of Badajoz. In these maps, the most representative characteristics of each stratum are also collected from a building perspective. In the study eight representative stratums were found. The geotechnical cartography has been obtained graphically by isolines, indicating the position and thickness of the stratums mentioned above. The study could be of interest both to technicians competent in the field of building and urban planning.El estudio de las propiedades del subsuelo resulta fundamental para el diseño de las cimentaciones y para prevenir futuras patologías estructurales. En este trabajo se analiza la información procedente de 459 sondeos del subsuelo de Badajoz. Se describe la generación de un banco de datos así como la elaboración de un conjunto de planos que constituyen el Mapa Geotécnico Básico de Badajoz. Están recogidas, así mismo, las características más representativas en cada estrato. Se han identificado ocho capas representativas del corte estratigráfico de la ciudad. La cartografía geotécnica ha sido obtenida gráficamente mediante isolíneas, indicando la posición y los espesores de las estratigrafías. El estudio puede resultar de interés tanto para técnicos (ingenieros y arquitectos) como para las autoridades con competencias en el ámbito urbanístico

Polaron effects in electron channels on a helium film

Using the Feynman path-integral formalism we study the polaron effects in quantum wires above a liquid helium film. The electron interacts with two-dimensional (2D) surface phonons, i.e. ripplons, and is confined in one dimension (1D) by an harmonic potential. The obtained results are valid for arbitrary temperature ($T$), electron-phonon coupling strength ($\alpha$), and lateral confinement ($\omega_{0}$). Analytical and numerical results are obtained for limiting cases of $T$, $\alpha$, and $\omega_{0}$. We found the surprising result that reducing the electron motion from 2D to quasi-1D makes the self-trapping transition more continuous.Comment: 6 pages, 7 figures, submitted to Phys. Rev.