A landsat remote sensing study of vegetation growing on mineralized terrain

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Estimativas das probabilidades de reconcepção em matrizes no Pantanal da Nhecolândia.

O objetivo deste estudo foi estimar a probabilidade de reconcepção em matrizes criadas na sub-região da Nhecolândia em função do mês de parição e condições climáticas no período de fecundação. The aim of this study was to estimate the probability of reconception in cows reared in the Nhecolândia sub-region, according to the month of calving and the weather conditions during the period of fertilization

Seleção e descarte de matrizes no Pantanal.

bitstream/CPAP/56312/1/ADM101.pdfFormato eletrônico

Formal conserved quantities for isothermic surfaces

Isothermic surfaces in $S^n$ are characterised by the existence of a pencil $\nabla^t$ of flat connections. Such a surface is special of type $d$ if there is a family $p(t)$ of $\nabla^t$-parallel sections whose dependence on the spectral parameter $t$ is polynomial of degree $d$. We prove that any isothermic surface admits a family of $\nabla^t$-parallel sections which is a formal Laurent series in $t$. As an application, we give conformally invariant conditions for an isothermic surface in $S^3$ to be special.Comment: 13 page

Manipulation of the dynamics of many-body systems via quantum control methods

We investigate how dynamical decoupling methods may be used to manipulate the time evolution of quantum many-body systems. These methods consist of sequences of external control operations designed to induce a desired dynamics. The systems considered for the analysis are one-dimensional spin-1/2 models, which, according to the parameters of the Hamiltonian, may be in the integrable or non-integrable limits, and in the gapped or gapless phases. We show that an appropriate control sequence may lead a chaotic chain to evolve as an integrable chain and a system in the gapless phase to behave as a system in the gapped phase. A key ingredient for the control schemes developed here is the possibility to use, in the same sequence, different time intervals between control operations.Comment: 10 pages, 3 figure

Probing the quantum phase transition in the Dicke model through mechanical vibrations

This paper is concerned with quantum dynamics of a system coupled to a critical reservoir. In this context, we employ the Dicke model which is known to exhibit a super radiant quantum phase transition (QPT) and we allow one of the mirrors to move under a linear restoring force. The electromagnetic field couples to the movable mirror though radiation pressure just like in typical optomechanical setups. We show that, in the thermodynamical limit, the super-radiant phase induces a classical driving force on the mirror without causing decoherence.Comment: 6 pages, 3 figures, final versio

One-Electron Singular Branch Lines of the Hubbard Chain

The momentum and energy dependence of the weight distribution in the vicinity of the one-electron spectral-function singular branch lines of the 1D Hubbard model is studied for all values of the electronic density and on-site repulsion $U$. To achieve this goal we use the recently introduced pseudofermion dynamical theory. Our predictions agree quantitatively for the whole momentum and energy bandwidth with the peak dispersions observed by angle-resolved photoelectron spectroscopy in the quasi-1D organic conductor TTF-TCNQ.Comment: Replaced with shortened version; 4 figure

Estimativa preliminar do conteúdo de nitrogênio depositado via fezes bovinas no Pantanal da Nhecolândia.

No Pantanal não é usual a prática de adubação e, nesta condição, a produtividade está intrinsecamente relacionada às entradas e saídas naturais de nutrientes do sistema, ou seja, a ciclagem de nutrientes. Neste sentido, o aproveitamento das excretas (urina e fezes) do rebanho constitui-se em uma importante via de retorno de nutrientes às plantas. Estima-se que cerca de 60% a 90% dos nutrientes ingeridos pelo gado retornam aos pastos na forma de fezes e urina. Como os nutrientes presentes nestas excretas apresentam-se mais concentrados e em formas mais disponíveis às plantas, este processo pode estimular o crescimento das forragens e contribuir, de acordo com Saunders, com mais de 70% da produção anual do pasto. Para considerar a excreção bovina como adubo natural do pasto, é fundamental ter conhecimento do aporte e da distribuição de nutrientes que retornam via excretas.bitstream/CPAP/56263/1/COT65.pdfFormato eletrônico