Controlo visual de um tapete-rolante

No presente artigo é apresentado o trabalho realizado no Laboratório de Sistemas Industriais, onde se pretende controlar a passagem de objectos num tapete rolante através de visão por computador. O sistema desenvolvido consiste num tapete rolante accionado por um servo motor da OMRON, com transmissão por correia. O controlo do servo motor é realizado por computador através de uma placa da National Instruments PCI-7344 com o adaptador UMI-7764. O sistema de visão consiste numa placa Matrox Meteor II e uma câmara CCD a cores. Pretende-se controlar a velocidade do tapete em função do numero de objectos a identificar e do tempo de processamento do anel de visão. Para tal foi necessário calibrar o sistema de visão, baseado num PC- Pentium II a 350 MHz com 32 Mb de RAM, tendo o software sido desenvolvido em Visual C++. O sistema de controlo encontra-se centralizado num PC-Pentium III a 850 MHz com 128 Mb de RAM, tendo o software sido desenvolvido no programa LABVIE

Runoff at the micro-plot and slope scale following wildfire, central Portugal

Through their effects on soil properties and vegetation/litter cover, wildfires can strongly enhance overland flow generation and accelerate soil erosion [1] and, thereby, negatively affect land-use sustainability as well as downstream aquatic and flood zones. Wildfires are a common phenomenon in present-day Portugal, devastating in an average year some 100.000 ha of forest and woodlands and in an exceptional year like 2003 over 400.000 ha. There therefore exists a clear need in Portugal for a tool that can provide guidance to post-fire land management by predicting soil erosion risk, on the one hand, and, on the other, the mitigation effectiveness of soil conservation measures. Such a tool has recently been developed for the Western U.S.A. [3: ERMiT] but its suitability for Portuguese forests will need to be corroborated by field observations. Testing the suitability of existing erosion models in recently burned forest areas in Portugal is, in a nutshell, the aim of the EROSFIRE projects. In the first EROSFIRE project the emphasis was on the prediction of erosion at the scale of individual hill slopes. In the ongoing EROSFIRE-II project the spatial scope is extended to include the catchment scale, so that also the connectivity between hill slopes as well as channel and road processes are being addressed. Besides ERMiT, the principal models under evaluation for slope-scale erosion prediction are: (i) the variant of USLE [4] applied by the Portuguese Water Institute after the wildfires of 2003; (ii) the Morgan–Morgan–Finney model (MMF) [5]; (iii) MEFIDIS [6]. From these models, MEFIDIS and perhaps MMF will, after successful calibration at the slope scale, also be applied for predicting catchment-scale sediment yields of extreme events

Runoff and erosion at the micro-plot and slope scale in a small burnt catchment, central Portugal

Wildfires can have important impacts on hydrological processes and soil erosion in forest catchments, due to the destruction of vegetation cover and changes to soil properties. However, the processes involved are non-linear and not fully understood. This has severely limited the understanding on the impacts of wildfires, especially in the up-scaling from hillslopes to catchments; in consequence, current models are poorly adapted for burnt forest conditions. The objective of this presentation is to give an overview of the hydrological response and sediment yield from the micro-plot to slope scale, in the first year following a wildfire (2008/2009) that burnt an entire catchment nearby the Colmeal village, central Portugal. The overview will focus on three slopes inside the catchment, with samples including: • Runoff at micro-plot scale (12 bounded plots) and slope scale (12 open plots); • Sediments and Organic Matter loss at micro-plot scale (12 bounded plots) and slope scale (12 open plots plus 3 Sediment fences); • Rainfall and Soil moisture data; • Soil Water Repellency and Ground Cover data. The analysis of the first year following the wildfire clearly shows the complexity of runoff generation and the associated sediment transport in recently burnt areas, with pronounced differences between hillslopes and across spatial scales as well as with marked variations through time. This work was performed in the framework of the EROSFIRE-II project (PTDC/AGR-CFL/70968/2006) which has as overall aim to predict soil erosion risk in recently burnt forest areas, including common post-fire forest management practices; the project focuses on the simultaneous measurement of runoff and soil erosion at multiple spatial scales.The results to be presented in this session are expected to show how sediment is generated, transported and exported in the Colmeal watershed; and contribute to understand and simulate erosion processes in burnt catchments, including for model development and evaluation

Optical demultiplexer device operating in the visible spectrum

In this paper, we present results on the use of multilayered a-SiC:H heterostructures as a device for wavelength-division demultiplexing of optical signals. These devices are useful in optical communications applications that use the wavelength division multiplexing technique to encode multiple signals into the same transmission medium. The device is composed of two stacked p-i-n photodiodes, both optimized for the selective collection of photo generated carriers. Band gap engineering was used to adjust the photogeneration and recombination rate profiles of the intrinsic absorber regions of each photodiode to short and long wavelength absorption in the visible spectrum. The photocurrent signal using different input optical channels was analyzed at reverse and forward bias and under steady state illumination. A demux algorithm based on the voltage controlled sensitivity of the device was proposed and tested. An electrical model of the WDM device is presented and supported by the solution of the respective circuit equations

Hydrological and erosion response at micro-plot to -catchment scale following forest wildfire, north-central Portugal

Wildfires can have important impacts on hydrological and soil erosion processes, due to the destruction of vegetation cover and changes to soil properties. According to Shakesby and Doerr (2006), these wildfire effects are: i) much better known at small spatial scales (especially erosion plots) than at the scale of catchments; ii) much better studied with respect to overland flow and streamflow (and, then, especially peak discharges) than to soil erosion. Following up on a precursor project studying runoff generation and the associated soil losses from micro-plot to slope-scale in Portuguese eucalypt forests, the EROSFIRE-II project addresses the connectivity of these processes across hillslopes as well as within the channel network. This is done in the Colmeal study area in central Portugal, where the outlet of an entirely burnt catchment of roughly 10 ha was instrumented with a gauging station continuously recording water level and tubidity, and five slopes were each equipped with 4 runoff plots of < 0,5 m2 (“micro-plot”) and 4 slope-scale plots as well as 1 slope-scale sediment fence. Starting one month after the August 2008 wildfire, the plots were monitored at 1- to 2-weekly intervals, depending on the occurrence of rainfall. The gauging station became operational at the end of November 2008, since the in-situ construction of an H-flume required several weeks. A preliminary analysis of the data collected till the end of 2008, focusing on two slopes with contrasting slope lengths as well as the gauging station: revealed clear differences in runoff and erosion between: (i) the micro-plot and slope-scale plots on the same hillslope; (ii) the two slopes; (iii) an initial dry period and a subsequent much wetter period; (iv) the slopes and the catchment-scale, also depending on the sampling period. These results suggest that the different processes govern the hydrological and erosion response at different spatial scales as well as for different periods, with soil water repellency playing a role during the initial post-fire period. The current presentation will review these preliminary results based on the data collected during the first year after the wildfire

Tinea Capitis in Adults. A Diagnosis to Consider?

A tinea capitis, uma infecção por fungos dermatófitos do couro cabeludo, é uma patologia rara no adulto, mesmo em áreas geográficas onde a doença é prevalente. Nestes casos está muitas vezes, mas não exclusivamente, associada a imunodepressão e habitualmente surge por exposição ao agente infeccioso em contactantes próximos. São fundamentais uma história clínica e um exame objectivo minuciosos que permitam equacionar a tinha do couro cabeludo como hipótese diagnóstica e proceder à colheita de amostras para exame micológico. Esta metodologia pode evitar a realização de exames complementares exaustivos ou a prescrição de tratamentos inadequados. Os autores descrevem três casos de tinea capitis em mulheres adultas – dois casos de infecção por Microsporum audouinii e um caso por Trichophyton soudanense. É apresentado o registo iconográfico dos casos e é efectuada breve revisão da literatura

Optical processing devices based on a-SiCH multilayer architectures

Red, green and blue optical signals were directed to an a-SiC:H multilayered device, each one with a specific transmission rate. The combined optical signal was analyzed by reading out, under different applied voltages, the generated photocurrent. Results show that when a chromatic time dependent wavelength combination with different transmission rates irradiates the multilayered structure, the device operates as a tunable wavelength filter and can be used in wavelength division multiplexing systems for short range communications. An application to fluorescent proteins detection is presented. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Seleção de rizobactérias autóctones de feijoeiro para controle biológico da mela ou teia micélica (Thanatephorus cucumeris).

Neste trabalho, buscou-se selecionar in vitro, por teste de antibiose direta (AD) e por determinação de compostos voláteis (ComVo) e in vivo, em casa-de-vegetação 150 isolados de rizobactérias, obtidos de feijoeiros sadios, capazes de inibir o crescimento de T. cucumeris e, consequentemente, a severidade da doença nas plantas. Assim, nos testes in vitro, em antibiose Direta (AD), os isolados foram semeados em placa de Petri com meio Kado e Heskett, (cinco por placa). Após 24h/27 oC, estes foram mortos com luz ultra-violeta. No centro da placa, discos de micélio T. cucumeris foram depositados e quatro dias após, avaliou-se a presença de halos de inibição do fungo. Nos ensaios de compsotos voláteis (ComVo), o fungo foi depositado na tampa da placa contendo BDA e uma rizobactéria foi semeada no fundo da mesma contendo meio 523. A placa foi selada e levada para BOD por 72h/27oC. Avaliou-se a velocidade de crescimento e o diâmetro máximo de crescimento do fungo. Nos testes in vivo, sementes de feijoeiro foram microbiolizadas com suspensão de rizobactérias (A540nm=0,4) por 12h. Semeou-se estas em copos plásticos de 500 mL contendo solo de barranco e manteve-se estes em casa-de-vegetação. Como controle, sementes embebidas em água destilada estéril. Aos 21 após a emergência das plantas, estas foram pulverizadas com uma suspensão de micélio triturado previamente em liquidificador (1,0x105 hifas/mL-1). Quatro dias após avaliou-se a severidade da doença nas folhas por meio de escala diagramática de severidade. Dos 150 isolados testados, cpafro-004, cpafro-007, cpafro-018, cpafro-023 e cpafro-038 foram capazes de inibir em AD o crescimento de T.cucumeris (0,5; 0,5; 0,7; 0,1; 0,3 cm diâmetro médio do halo respectiv.) e 46 produziram ComVo, sendo Cpafro 41, 33 e 20 foram os melhores, com máximo de crescimento da colônia de 2,8; 3,2 e 3,4 de diâmetro respectivamente. Nos testes in vivo, cpafro-26, cprafro-90 e cpafro-60 reduziram a severiade da mela (9%, 11% e 13% de severidade respect.) quando comparados com o controle com água (67% de severidade). Estes resultados demonstram a potencialidade do uso de rizobactérias no controle da mela do feijoeiro