3,283 research outputs found

    The Amazon and climate

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    The climatologies of cloudiness and precipitation for the Amazon, are reviewed and the physical causes of some of the observed features and those which are not well known are explained. The atmospheric circulation over the Amazon is discussed on the large scale tropical circulations forced by deep diabatic heating sources. Weather deforestation which leads to a reduction in evapotranspiration into the atmosphere, and a reduction in precipitation and its implicated for the gobal climate is discussed. It is indicated that a large scale clearing of tropical rainforests there would be a reduction in rainfall which would have global effects on climate and weather both in the tropical and extratropical regions

    Generalized Nonlinear Proca Equation and its Free-Particle Solutions

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    We introduce a non-linear extension of Proca's field theory for massive vector (spin 11) bosons. The associated relativistic nonlinear wave equation is related to recently advanced nonlinear extensions of the Schroedinger, Dirac, and Klein-Gordon equations inspired on the non-extensive generalized thermostatistics. This is a theoretical framework that has been applied in recent years to several problems in nuclear and particle physics, gravitational physics, and quantum field theory. The nonlinear Proca equation investigated here has a power-law nonlinearity characterized by a real parameter qq (formally corresponding to the Tsallis entropic parameter) in such a way that the standard linear Proca wave equation is recovered in the limit q→1q \rightarrow 1. We derive the nonlinear Proca equation from a Lagrangian that, besides the usual vectorial field Ψμ(x⃗,t)\Psi^{\mu}(\vec{x},t), involves an additional field Φμ(x⃗,t)\Phi^{\mu}(\vec{x},t). We obtain exact time dependent soliton-like solutions for these fields having the form of a qq-plane wave, and show that both field equations lead to the relativistic energy-momentum relation E2=p2c2+m2c4E^{2} = p^{2}c^{2} + m^{2}c^{4} for all values of qq. This suggests that the present nonlinear theory constitutes a new field theoretical representation of particle dynamics. In the limit of massless particles the present qq-generalized Proca theory reduces to Maxwell electromagnetism, and the qq-plane waves yield localized, transverse solutions of Maxwell equations. Physical consequences and possible applications are discussed

    The Amazonia Third Way Initiative: The Role of Technology to Unveil the Potential of a Novel Tropical Biodiversity-Based Economy

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    Abstract For the last two decades, the Amazon development debate has been torn between attempts to reconcile two rather opposing views of land use: on one hand, a vision of setting aside large tracts of the Amazon forests for conservation purposes (referred hereafter to as The First Way) and, on the other hand, seeking a ‘sustainable’ resource-intensive development, mostly through agriculture/livestock, energy and mining (referred hereafter to as The Second Way). The decrease of Brazilian Amazon deforestation from 2005 to 2014 (about 75% decline) opens a window of opportunity to conceive a novel sustainable development paradigm: The Amazonia Third Way initiative (A3W). It can represent a new opportunity emerging to protect the Amazon ecosystems and the indigenous and traditional peoples who are their custodians and at the same time develop a vibrant, socially inclusive biodiversity-driven ‘green economy’ in the Amazon by harnessing Nature’s value through the physical, digital and biological technologies of the 4th Industrial Revolution (4IR). 4IR technologies are increasingly harnessing these assets across many industries from pharmaceutical to energy, food, cosmetics, materials and mobility, and making profits. A3W addresses ways to channel to the Amazon the benefits of the 4IR for the creation of bio-industries and local development as it protects the forests

    Grounded theory: from analysis of social practices to theory building: the ontological and epistemic grounding of four case studies in an Organisational Learning research project

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    Trabalho apresentado em 9th European Conference on Research Methodology for Business and Management Studies, 23-24 junho 2010, Madrid, EspanhaN/

    The radical need for semiotics in IS research and practice: why the urgency?

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    Trabalho apresentado em 12th International Conference on Informatics and Semiotics in Organisations ICISO, 19-21 July 2010, Reading, UK.N/

    "Only Lyon": innovation dynamics of regional entrepreneurship and internacionalisation

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    Trabalho apresentado em 14º Workshop, Empreendedorismo e Desenvolvimento Regional,Associação Portuguesa de Desenvolvimento Regional, 9 outubro 2012, Setúbal, Portugalinfo:eu-repo/semantics/publishedVersio

    Limit situations, affects and resilience: psychoanalysis and M. Henry phenomenology

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    Trabalho apresentado em XIX International Forum of Psychoanalysis - Violence, Terror and Terrorism today: psychoanalytic perspectives, 12-15 maio 2016, New York City, NY, USAN/

    Toward a better understanding of the doping mechanism involved in Mo(tfd-COCF3)3_3)_3 doped PBDTTT-c

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    In this study, we aim to improve our understanding of the doping mechanism involved in the polymer PBDTTT-c doped with(Mo(tfd-COCF3)3. We follow the evolution of the hole density with dopant concentration to highlight the limits of organic semiconductor doping. To enable the use of doping to enhance the performance of organic electronic devices, doping efficiency must be understood and improved. We report here a study using complementary optical and electrical characterization techniques, which sheds some light on the origin of this limited doping efficiency at high dopant concentration. Two doping mechanisms are considered, the direct charge transfer (DCT) and the charge transfer complex (CTC). We discuss the validity of the model involved as well as its impact on the doping efficiency.Comment: Accepted manuscript, J. Appl. Phy
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