Manejo do nitrogênio para o arroz Irrigado: doses e parcelamento da adubação em cobertura.

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Radion production in exclusive processes at CERN LHC

In the Randall-Sundrum (RS) scenario the compactification radius of the extra dimension is stabilized by the radion, which is a scalar field lighter than the graviton Kaluza-Klein states. It implies that the detection of the radion will be the first signature of the stabilized RS model. In this paper we study the exclusive production of the radion in electromagnetic and diffractive hadron - hadron collisions at the LHC. Our results demonstrate that the diffractive production of radion is dominant and should be feasible of study at CERN LHC.Comment: 6 pages, 3 figures, 1 tabl

Study of the Organic Extraction and Acidic Leaching of Chars Obtained in the Pyrolysis of Plastics, Tire Rubber and Forestry Biomass Wastes

AbstractThe present work aims to perform a characterization of chars obtained in the co-pyrolysis of waste mixtures composed by plastics, tires and pine biomass, to provide knowledge about the composition, leaching behavior and risk assessment of these materials in order to define strategies for their possible valorization or safe disposal. The chars were submitted to sequential solvent extractions with organic solvents of increasing polarity that allow the recovery of significant amounts of the pyrolysis oils trapped in the crude chars improving the yield of the pyrolysis liquids. An acidic demineralization procedure was successfully applied to the chars and high efficiency removals of the majority of the heavy metals were achieved. The demineralization study also demonstrated that hazardous heavy metals such as chromium, nickel and cadmium are significantly immobilized in the char matrix, and other heavy metals of concern such as zinc and lead will not represent a leaching problem if acidic conditions were not used. The obtained chars present sufficient quality and characteristics to be used as fuel or alternatively, to be used as adsorbents or precursors of activated carbon

Generation and analysis of synthetic data via Bayesian networks: a robust approach for uncertainty quantification via Bayesian paradigm

Safe and reliable disclosure of information from confidential data is a challenging statistical problem. A common approach considers the generation of synthetic data, to be disclosed instead of the original data. Efficient approaches ought to deal with the trade-off between reliability and confidentiality of the released data. Ultimately, the aim is to be able to reproduce as accurately as possible statistical analysis of the original data using the synthetic one. Bayesian networks is a model-based approach that can be used to parsimoniously estimate the underlying distribution of the original data and generate synthetic datasets. These ought to not only approximate the results of analyses with the original data but also robustly quantify the uncertainty involved in the approximation. This paper proposes a fully Bayesian approach to generate and analyze synthetic data based on the posterior predictive distribution of statistics of the synthetic data, allowing for efficient uncertainty quantification. The methodology makes use of probability properties of the model to devise a computationally efficient algorithm to obtain the target predictive distributions via Monte Carlo. Model parsimony is handled by proposing a general class of penalizing priors for Bayesian network models. Finally, the efficiency and applicability of the proposed methodology is empirically investigated through simulated and real examples

Exact Foldy-Wouthuysen transformation for gravitational waves and magnetic field background

We consider an exact Foldy-Wouthuysen transformation for the Dirac spinor field on the combined background of a gravitational wave and constant uniform magnetic field. By taking the classical limit of the spinor field Hamiltonian we arrive at the equations of motion for the non-relativistic spinning particle. Two different kinds of the gravitational fields are considered and in both cases the effect of the gravitational wave on the spinor field and on the corresponding spinning particle may be enforced by the sufficiently strong magnetic field. This result can be relevant for the astrophysical applications and, in principle, useful for creating the gravitational wave detectors based on atomic physics and precise interferometry

Envelhecimento, trabalho e tempo livre: elaborando projetos de vida.

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Contribuições para o desenvolvimento da Educação Ambiental em Unidades de Conservação no Brasil a partir de programas educativos do Geoparque Naturtejo (Portugal)

O presente trabalho pretende apresentar os resultados de estudos realizados sobre programas educativos desenvolvidos no Geoparque Naturtejo (Portugal) e avaliar se os programas podem contribuir para o desenvolvimento de programas de preservação e educação ambiental em Unidades de Conservação – UC brasileiras cuja organização e sistematização de uso e ocupação tem como base o Sistema Nacional de Unidades de Conservação (SNUC). A pesquisa envolveu pesquisa documental, entrevistas com responsáveis por programas educativos do geoparque e acompanhamento de atividades de campo. A educação ambiental (EA) desenvolvida no geoparque possui três características notáveis: 1. EA naturalmente inclusiva, pois busca integrar os moradores locais; 2. Os conteúdos de EA estão integrados a conteúdos do ensino formal; 3. A EA junto às escolas e comunidades locais é muito ativa. A EA praticada nas UC brasileiras foca somente em quem as visita, geralmente excluindo a comunidade ou escolas da região; exige-se proteção local sem que a comunidade compreenda os processos relacionados ao ambiente. Embora os objetivos e finalidades de um geoparque não sejam os mesmos definidos para as UC brasileiras, consideramos que o modelo dos programas educativos do geoparque estudado poderia ser uma proposta mais efetiva para desenvolver a educação ambiental no Brasil.CAPES pelo apoio financeiro com bolsas do programa PDSE, Doutorado Sanduíche no Exterior, e à FAPESP, Proc. 2009/01741-9.info:eu-repo/semantics/publishedVersio

A method to incorporate uncertainty in the classification of remote sensing images

The aim of this paper is to investigate if the incorporation of the uncertainty associated with the classification of surface elements into the classification of landscape units (LUs) increases the results accuracy. To this end, a hybrid classification method is developed, including uncertainty information in the classification of very high spatial resolution multi-spectral satellite images, to obtain a map of LUs. The developed classification methodology includes the following steps: (1) a pixel-based hard classification with a probabilistic Bayesian classifier; (2) computation of the posterior probabilities and quantification of the classification uncertainty using an uncertainty measure; (3) image segmentation and (4) object classification based on decision rules. The classification of the resulting objects into LUs is performed considering a set of decision rules that incorporate the pixelbased classification uncertainty. The proposed methodology was tested on the classification of an IKONOS satellite image. The accuracy of the classification was computed using an error matrix. The comparison between the results obtained with the proposed approach and those obtained without considering the classification uncertainty revealed a 12% increase in the overall accuracy. This shows that the information about uncertainty can be valuable when making decisions and can actually increase the accuracy of the classification results.info:eu-repo/semantics/publishedVersio

Plasmonic silicon Schottky photodetectors: the physics behind graphene enhanced internal photoemission

Recent experiments have shown that the plasmonic assisted internal photoemission from a metal to silicon can be significantly enhanced by introducing a monolayer of graphene between the two media. This is despite the limited absorption in a monolayer of undoped graphene ( ∼ π α = 2.3 % ). Here we propose a physical model where surface plasmon polaritons enhance the absorption in a single-layer graphene by enhancing the field along the interface. The relatively long relaxation time in graphene allows for multiple attempts for the carrier to overcome the Schottky barrier and penetrate into the semiconductor. Interface disorder is crucial to overcome the momentum mismatch in the internal photoemission process. Our results show that quantum efficiencies in the range of few tens of percent are obtainable under reasonable experimental assumptions. This insight may pave the way for the implementation of compact, high efficiency silicon based detectors for the telecom range and beyond