23,951 research outputs found

    Lorentz-breaking effects in scalar-tensor theories of gravity

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    In this work, we study the effects of breaking Lorentz symmetry in scalar-tensor theories of gravity taking torsion into account. We show that a space-time with torsion interacting with a Maxwell field by means of a Chern-Simons-like term is able to explain the optical activity in syncrotron radiation emitted by cosmological distant radio sources. Without specifying the source of the dilaton-gravity, we study the dilaton-solution. We analyse the physical implications of this result in the Jordan-Fierz frame. We also analyse the effects of the Lorentz breaking in the cosmic string formation process. We obtain the solution corresponding to a cosmic string in the presence of torsion by keeping track of the effects of the Chern-Simons coupling and calculate the charge induced on this cosmic string in this framework. We also show that the resulting charged cosmic string gives us important effects concerning the background radiation.The optical activity in this case is also worked out and discussed.Comment: 10 pages, no figures, ReVTex forma

    Non-collinear coupling between magnetic adatoms in carbon nanotubes

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    The long range character of the exchange coupling between localized magnetic moments indirectly mediated by the conduction electrons of metallic hosts often plays a significant role in determining the magnetic order of low-dimensional structures. In addition to this indirect coupling, here we show that the direct exchange interaction that arises when the moments are not too far apart may induce a non-collinear magnetic order that cannot be characterized by a Heisenberg-like interaction between the magnetic moments. We argue that this effect can be manipulated to control the magnetization alignment of magnetic dimers adsorbed to the walls of carbon nanotubes.Comment: 13 pages, 5 figures, submitted to PR

    Dynamics of the topological structures in inhomogeneous media

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    We present a general review of the dynamics of topological solitons in 1 and 2 dimensions and then discuss some recent work on the scattering of various solitonic objects (such as kinks and breathers etc) on potential obstructions.Comment: based on the talk given by W.J. Zakrzewski at QTS5. To appear in the Proceedings in a special issue of Journal of Physics

    Dynamics of the topological structures in inhomogeneous media

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    We present a general review of the dynamics of topological solitons in 1 and 2 dimensions and then discuss some recent work on the scattering of various solitonic objects (such as kinks and breathers etc) on potential obstructions.Comment: based on the talk given by W.J. Zakrzewski at QTS5. To appear in the Proceedings in a special issue of Journal of Physics

    Dynamics of the topological structures in inhomogeneous media

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    We present a general review of the dynamics of topological solitons in 1 and 2 dimensions and then discuss some recent work on the scattering of various solitonic objects (such as kinks and breathers etc) on potential obstructions.Comment: based on the talk given by W.J. Zakrzewski at QTS5. To appear in the Proceedings in a special issue of Journal of Physics

    Estudo de caso: Custo operacional efetivo de plantio de pastagem em integração lavoura-pecuária (Sorghum bicolor L. BRS 655 e Panicum maximum cv. Mombaça) em Ariquemes-RO, Brasil.

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    Avaliou-se o custo operacional efetivo (COE) até o ponto de ensilagem de integração lavoura pecuária de sorgo mais mombaça, para alimentação de vacas de leite e ovinos, no IFRO de Ariquemes-RO. Após correção da saturação de bases para 60%, plantou-se 17,5 kg/ha de sorgo BRS 655+17,5 kg/ha de mombaça com aplicação de 351 kg/ha de 04-24-16 mais 87,5 kg de sulfato de amônio na base e 350,9 kg em cobertura. Por meio de análise exploratória, verificou-se 80% do COE para insumos e 20% para serviços, onde adubo basal, sementes, adubo nitrogenado e calcário tiveram maior contribuição no COE, que pode ser minimizada com regulagem e maior treinamento da mão de obra

    Hospital-based pulmonary rehabilitation in patients with COPD in Sweden–A national survey

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    SummaryPulmonary rehabilitation (PR) is an evidence-based, multidisciplinary and cost-effective intervention that leads to improved health in patients with chronic obstructive pulmonary disease, COPD. However, the availability of PR programs varies between and within different countries. The aim of this study was to investigate the availability and content of hospital-based PR programs in patients with COPD in Sweden.A cross-sectional descriptive design was applied using a web-based questionnaire which was sent out to all hospitals in Sweden. The questionnaire consisted of 32 questions that concerned availability and content of PR in patients with COPD during 2011.Seventy out of 71 hospitals responded the electronic survey. Forty-six (66%) hospitals offered PR for patients with COPD. Around 75% of the hospitals in southern and middle parts of Sweden and 33% of the hospitals in the northern part offered PR. Thirty-four percent of the patients declined participation. A total number of 1355 patients participated in PR which represents 0.2% of the COPD population in Sweden. All hospitals had exercise training as major component and 76% offered an educational program.Not even half a percent of the patients with COPD in Sweden took part in a hospital-based PR program during 2011. There was a considerable geographic discrepancy in availability over the country. To enable a greater part of the increasing number of patients with COPD to take part in this evidence-based treatment, there is a need of evaluating other settings of PR programs; in primary care, at home and/or over the internet

    3D IoT dystem for environmental and energy consumption monitoring system

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    Energy consumption in buildings depends on the local climate, building characteristics, and user behavior. Focusing on user interaction, this research work developed a novel approach to monitoring and interaction with local users by providing in situ context information through graphic descriptions of energy consumption and indoor/outdoor environment parameters: temperature, luminosity, and humidity, which are routinely measured in real-time and stored to identify consumption patterns and other savings actions. To involve local users, collected data are represented in 3D color representation using building 3d models. A simplified color scale depicts environmental comfort (low/comfortable/high temperature/relative humidity) and energy consumption (above/below usual patterns). We found that these indices induced user commitment and increased their engagement and participation in saving actions like turning off lights and better management of air conditioning systems.info:eu-repo/semantics/publishedVersio
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