Contribuição da pesquisa florestal para um ecossistema em extinção: floresta atlântica do Nordeste do Brasil.

Neste levantameno procurou-se inserir os aspectos naturais e sociais no processo historico do desenvolvimento da ocupacao dessa regiao, principalmente na faixa da Floresta Atlantica. Essa ocupacao desenfreada vem contribuindo para o desaparecimento da mata e trazendo tanto problemas ecologicos como sociais, uma vez que a degradacao das florestas interfere diretamente na qualidade de vida de homem.bitstream/item/54515/1/CPATC-DOCUMENTOS-21-CONTRIBUICAO-DA-PESQUISA-FLORESTAL-PARA-UM-ECOSSISTEMA-EM-EXTINCAO-FLORESTA-A.pd

Estudo fenológico de espécies arbóreas da floresta ombrófila mista (floresta com araucária), no Município de Colombo-PR.

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Monitoramento dos estádios fenológicos reprodutivos da cerejeira-do-mato.

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Floração e frutificação da cerejeira-do-mato, em áreas fragmentadas da floresta ombrófila mista, no município de Colombo, PR.

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Effect of phonon scattering by surface roughness on the universal thermal conductance

The effect of phonon scattering by surface roughness on the thermal conductance in mesoscopic systems at low temperatures is calculated using full elasticity theory. The low frequency behavior of the scattering shows novel power law dependences arising from the unusual properties of the elastic modes. This leads to new predictions for the low temperature depression of the thermal conductance below the ideal universal value. Comparison with the data of Schwab et al. [Nature 404, 974 (2000)] suggests that surface roughness on a scale of the width of the thermal pathway is important in the experiment.Comment: 6 pages, 3 figure

Quantum chaos in nanoelectromechanical systems

We present a theoretical study of the electron-phonon coupling in suspended nanoelectromechanical systems (NEMS) and investigate the resulting quantum chaotic behavior. The phonons are associated with the vibrational modes of a suspended rectangular dielectric plate, with free or clamped boundary conditions, whereas the electrons are confined to a large quantum dot (QD) on the plate's surface. The deformation potential and piezoelectric interactions are considered. By performing standard energy-level statistics we demonstrate that the spectral fluctuations exhibit the same distributions as those of the Gaussian Orthogonal Ensemble (GOE) or the Gaussian Unitary Ensemble (GUE), therefore evidencing the emergence of quantum chaos. That is verified for a large range of material and geometry parameters. In particular, the GUE statistics occurs only in the case of a circular QD. It represents an anomalous phenomenon, previously reported for just a small number of systems, since the problem is time-reversal invariant. The obtained results are explained through a detailed analysis of the Hamiltonian matrix structure.Comment: 14 pages, two column

O plastocrono e filocrono aparente em Araucaria angustifolia (Bert.) O. Ktze. em estágio juvenil, no Município de Colombo, PR.

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Fenologia reprodutiva do capororocão (Myrsine umbellata) em áreas da Floresta Ombrófila Mista, no município de Colombo, PR.

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