A new data reduction scheme to obtain the mode II fracture properties of Pinus Pinaster wood

In this work a numerical study of the End Notched Flexure (ENF) specimen was performed in order to obtain the mode II critical strain energy released rate (GIIc) of a Pinus pinaster wood in the RL crack propagation system. The analysis included interface finite elements and a progressive damage model based on indirect use of Fracture Mechanics. The difficulties in monitoring the crack length during an experimental ENF test and the inconvenience of performing separate tests in order to obtain the elastic properties are well known. To avoid these problems, a new data reduction scheme based on the equivalent crack concept was proposed and validated. This new data reduction scheme, the Compliance-Based Beam Method (CBBM), does not require crack measurements during ENF tests and additional tests to obtain elastic properties.FCT - POCTI/EME/45573/200

Finite element analysis of the ECT test on mode III interlaminar fracture of carbon-epoxy composite laminates

In this work a parametric study of the Edge Crack Torsion (ECT) specimen was performed in order to maximize the mode III component (GIII) of the strain energy release rate for carbon-epoxy laminates. A three-dimensional finite element analysis of the ECT test was conducted considering a [90/0/(+45/-45)2/(-45/+45)2/0/90]S lay-up. The main objective was to define an adequate geometry to obtain an almost pure mode III at crack front. The geometrical parameters studied were specimen dimensions, distance between pins and size of the initial crack. The numerical results demonstrated that the ratio between the specimen length and the initial crack length had a significant effect on the strain energy release rate distributions. In almost all of the tested configurations, a mode II component occurred near the edges but it did not interfere significantly with the dominant mode III state.FCT - POCTI/EME/45573/200

Experimental evidence of laser power oscillations induced by the relative Fresnel (Goos-Haenchen) phase

The amplification of the relative Fresnel (Goos-Haenchen) phase by an appropriate number of total internal reflections and the choice of favorable incidence angles allow to observe full oscillations in the power of a DPSS laser transmitted through sequential BK7 blocks. The experimental results confirm the theoretical predictions. The optical apparatus used in this letter can be seen as a new type of two-phase ellipsometric system where the phase of the complex refractive index is replaced by the relative Fresnel (Goos-Haenchen) phase.Comment: 7 pages, 3 figures, 1 tabl

Evolution of deforestation in the Brazilian Pantanal and surroundings in the timeframe 1976 - 2008.

Maps elaborated from five different periods were recovered and inserted within a single GIS. Considering these maps, the evolution of deforestation in the Pantanal and its surroundings in Brazil was analyzed for the last 32 years and scenarios were described for the timeframe 2010-2050. The results for the different BAP (Floodplain and Plateau), BAP (Mato Grosso and Mato Grosso do Sul States), BAP (Biomes: Pantanal, Cerrado and Amazon). Until 2008, the deforestation on the Pantanal floodplain affected 12,14% of its area, while on the Plateau 58,90% were concerned. The actual deforestation percentages indicate that, if no effective control actions are taken, the natural vegetation from this region could be eliminated till 2050. As an instrument for the effective deforestation control, we suggest the implantation of a deforestation monitoring system on the river basin of the Upper Paraguay, based on information technology.Número especial

Identificação de duplicatas de acessos de Manihot esculenta Crantz.

A mandioca (Manihot esculenta Crantz) é uma planta nativa do Brasil, o que garante ao país posição de destaque no cenário internacional, em relação aos recursos genéticos da espécie. Muitos acessos são armazenados nos Bancos Ativos de Germoplasma (BAG) que tem como missão, a conservação e o uso deste recurso genético para o desenvolvimento de novos produtos e tecnologias. Contudo, como a mandioca é um produto nacional e o trabalho de coleta do germoplasma é feito em diferentes regiões, é comum o uso de diferentes nomes para um mesmo material

Perfil socioeconômico e ecológico dos agricultores familiares irrigantes do Semiárido sergipano.

A FUNDER, em parceria com a Embrapa Semiárido, divulga com este trabalho o perfil socioeconômico e ecológico dos agricultores familiares irrigantes do semiárido sergipano. As pesquisas foram realizadas em nove municípios, treze localidades e 248 Unidades de Produção (UPI). Realizaram-se a validação e qualificação dos microdados armazenados nos Bancos de Dados, os quais permitiram identificar as Análises de Perigos e Pontos Críticos de Controle do uso de agrotóxicos associados ao Código de Boas Práticas Agrícola (BPAs). Dos nove municípios pesquisados, um terço deles não apresentou nenhum agricultor que atendesse ao requisito de rastreabilidade do produto. O maior nível de aceitação para a rastreabilidade do produto foi Neópolis (69,2%). Quanto ao requisito de registro do produto e rastreabilidade do processo produtivo foi atendido por apenas 29,3% dos agricultores pesquisados, destacando-se, também, o município de Neópolis, com um índice de 84,6% de atendimento a este requisito. Diante da realidade apresentada, resulta serem necessários à adoção de medidas mitigadoras e de educação ambiental continuada, por meio da implementação de um Centro Vocacional Tecnológico de Modernização da Agricultura Irrigada Familiar no Semiárido Sergipano, principalmente, dirigido aos jovens agricultores irrigantes, visando minimizar os riscos observados

An extreme paucity of second population AGB stars in the normal globular cluster M4

Galactic Globular clusters (GCs) are now known to harbour multiple stellar populations, which are chemically distinct in many light element abundances. It is becoming increasingly clear that asymptotic giant branch (AGB) stars in GCs show different abundance distributions in light elements compared to those in the red giant branch (RGB) and other phases, skewing toward more primordial, field-star-like abundances, which we refer to as subpopulation one (SP1). As part of a larger program targeting giants in GCs, we obtained high-resolution spectra for a sample of 106 RGB and 15 AGB stars in Messier 4 (NGC 6121) using the 2dF+HERMES facility on the Anglo-Australian Telescope. In this Letter we report an extreme paucity of AGB stars with [Na/O] > -0.17 in M4, which contrasts with the RGB that has abundances up to [Na/O] =0.55. The AGB abundance distribution is consistent with all AGB stars being from SP1. This result appears to imply that all subpopulation two stars (SP2; Na-rich, O-poor) avoid the AGB phase. This is an unexpected result given M4's horizontal branch morphology -- it does not have an extended blue horizontal branch. This is the first abundance study to be performed utilising the HERMES spectrograph.Comment: 5 pages, 2 figures, 4 tables (full Table 1 online). Accepted for publication in MNRAS Letter