Imagens de satélite nas séries iniciais do ensino fundamental: o conhecimento do lugar como ponto de partida para a educação ambiental na agricultura.

As imagens de satélite estão cada vez mais difundidas no setor educacional devido a massificação da Internet e a utilização de novas tecnologias no processo de ensino-aprendizagem. Nas primeiras séries do ensino fundamental, a aquisição de conhecimentos a respeito do lugar de vivência do aluno (escola, bairro rural ou urbano) e das inter-relações desse lugar com o município (maior dimensão) é um passo importante no aprendizado e na compreensão das questões ambientais, as quais extrapolam os limites espaciais delimitados pelo homem

Convexity in partial cubes: the hull number

We prove that the combinatorial optimization problem of determining the hull number of a partial cube is NP-complete. This makes partial cubes the minimal graph class for which NP-completeness of this problem is known and improves some earlier results in the literature. On the other hand we provide a polynomial-time algorithm to determine the hull number of planar partial cube quadrangulations. Instances of the hull number problem for partial cubes described include poset dimension and hitting sets for interiors of curves in the plane. To obtain the above results, we investigate convexity in partial cubes and characterize these graphs in terms of their lattice of convex subgraphs, improving a theorem of Handa. Furthermore we provide a topological representation theorem for planar partial cubes, generalizing a result of Fukuda and Handa about rank three oriented matroids.Comment: 19 pages, 4 figure

Determination of Mode I Fracture Toughness of Cortical Human Bone using the DCB Test

The fracture behaviour of human cortical bone was analysed considering a miniaturized version of theDouble Cantilever Beam (DCB) test. A specific data reduction scheme based on crack equivalentconcept was used to obtain the resistance curves. The definition of the cohesive laws mimicking thefracture process was performed measuring the crack tip opening displacement by digital imagecorrelation during the test. The differentiation of the relation between the strain energy release rate andcrack tip opening displacement allows to define the experimental cohesive law. In order to validate theprocedure, trapezoidal cohesive laws with bilinear softening were adjusted to the experimental ones.The DCB tests were simulated by finite element analysis including cohesive zone modelling with theadjusted laws. The resulting numerical load-displacement and resistance curves were compared withthe numerical ones. Good agreement was obtained which validates the proposed procedure

Effect of guar gum on the physicochemical, thermal, rheological and textural properties of green edam cheese

In attempts to produce a low-fat cheese with a rheology and texture similar to that of a full-fat cheese, guar gum (within 0.0025–0.01%; w/v, final concentration) was added to low-fat milk. The obtained cheeses were characterised regarding their physicochemical, thermal, rheological and textural properties. Control cheeses were also produced with low and full-fat milk. The physicochemical properties of the guar gum modified cheeses were similar to those of the low-fat control. No significant differences were detected in the thermal properties (concerning the enthalpy and profile of water desorption) among all types of cheeses. The rheological behaviour of the 0.0025% modified cheese was very similar to the full-fat control. Overall, no trend was observed in the texture profile (hardness, cohesiveness, gumminess and elasticity) of the modified cheeses versus guar gum concentration, as well as in comparison with the control groups, suggesting that none of the studied polysaccharide concentrations simulated the textural functions of fat in Edam cheese

On the Meaning of the String-Inspired Noncommutativity and its Implications

We propose an alternative interpretation for the meaning of noncommutativity of the string-inspired field theories and quantum mechanics. Arguments are presented to show that the noncommutativity generated in the stringy context should be assumed to be only between the particle coordinate observables, and not of the spacetime coordinates. Some implications of this fact for noncomutative field theories and quantum mechanics are discussed. In particular, a consistent interpretation is given for the wavefunction in quantum mechanics. An analysis of the noncommutative theories in the Schr\"odinger formulation is performed employing a generalized quantum Hamilton-Jacobi formalism. A formal structure for noncommutative quantum mechanics, richer than the one of noncommutative quantum field theory, comes out. Conditions for the classical and commutative limits of these theories have also been determined and applied in some examples.Comment: References, comments, and footnotes are included; some changes in section