Asymmetrical bloch branes and the hierarchy problem

We investigate a two scalar fields split braneworld model which leads to a possible approach to the hierarchy problem within the thick brane scenario. The model exhibits a resulting asymmetric warp factor suitable for this purpose. The solution is obtained by means of the orbit equation approach for a specific value of one of the parameters. Besides, we analyze the model qualitative behaviour for arbitrary parameters by inspecting the underlying dynamical system defined by the equations which give rise to the braneworld model. We finalize commenting on the metric fluctuation and stability issues.Comment: 8 pages, 7 figure

Homeopatia: uma opção de tratamento da mamite bovina

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Mechanical performance of lap joints of flat roof waterproofing membranes subjected to artificial weathering

The flat roof of a building, here understood as the whole of every construction element from the ceiling to the surface exposed to climatic agents, is made of a set of horizontal or quasi-horizontal layers that satisfy its functional demands. The waterproofing layer is fundamental in most flat roofs and, of the various options, single-layer systems made of prefabricated membranes and mechanically fastened are one of the most frequently used in Portugal. This solution is also used to repair roofs’ waterproofing systems without having to remove the existing layers, thus reducing the cost. However, it is well known that the performance of these systems is strongly influenced by the efficiency of the membrane fastenings, which is directly related to the membranes’ nature and the design and execution of the lap joints. Many of the anomalies that occur are related to the deficient execution of the membranes’ lap joints1–3 and the consequent faulty performance when subjected to average environmental agents. Studies undertaken in Portugal on the behavior of lap joints in membranes made or commercialized in this country4,5 have corroborated other studies in this area and shown that certain membranes perform worse than others when used in single-layer systems. Three different solutions were tested: amyloid precursor protein (APP)- and Styrene-Butadiene-Styrene (SBS)-modified bituminous membranes and polyvinyl chloride (PVC) membranes. Of the bituminous membranes, the SBS ones produced and commercialized in Portugal presented, as expected, much more satisfactory mechanical characteristics than the APP ones, thus justifying a more thorough study of their suitability for use in mechanically fastened single-layer systems.info:eu-repo/semantics/publishedVersio

Custo de produção de mudas de citros produzidas em Viveiro-telado.

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Dieta artificial para criação de Cosmopolites sordidus (Germ.)(Col.: Curculionidae) visando a programas de manejo integrado da praga.

A broca-do-rizoma, Cosmopolites sordidus (Germ.), é considerada a mais severa praga da bananeira, em razão dos prejuízos causados às plantas e da sua ampla distribuição geográfica. Essa praga ocorre em todas as regiões brasileiras e seus danos são causados pelas larvas que abrem galerias no rizoma e base do pseudocaule. O ataque dessa praga, além de reduzir o tamanho dos cachos comprometendo até 50 % da produção, provoca enfraquecimento das plantas, aumento na queda das bananeiras e favorece o ataque do mal-do-Panamá. Considerando a variabilidade genética existente nas populações de C. sordidus e suas implicações na seleção e avaliação de técnicas de controle de pragas, o estabelecimento de um programa de criação da broca-do-rizoma em laboratório é fundamental para o alcance de resultados promissores no manejo integrado do inseto. Este trabalho tem como objetivo determinar diferenças biológicas entre populações de C. sordidus provenientes de regiões produtoras de banana no Brasil e selecionar a(s) dieta(s) mais adequada(s) ao desenvolvimento de populações de C. sordidus em laboratório.PDF. 025

Effects of three pesticides on the avoidance behavior of earthworms in laboratory tests performed under temperate and tropical conditions.

Little research has been performed on the impact of pesticides on earthworms under tropical conditions. Taking into consideration the oftenlimited resources in tropical countries, simple screening tests are needed. Therefore, it was investigated whether three pesticides relevant for the Brazilian Amazon (benomyl, carbendazim, lambda-cyhalothrin) affect the avoidance behavior of the earthworm Eisenia fetida. The tests were performed for two days according to ISO guideline 17512 but were adapted to tropical conditions (i.e. test substrate, test organism and temperature). The results indicate that this test gives reproducible and reliable results. Toxicity values (NOEC, EC50) are lower than those determined in 14 day-acute mortality tests and are approximately in the same range such as those found in 56 day-chronic reproduction tests with the same earthworm species, which were performed in parallel. Therefore, the use of the earthworm avoidance tests is recommended as a screening tool for the risk assessment of pesticides

Desempenho econômico da citricultura em propriedade familiar da Zona Sul do RS.

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