4,452 research outputs found
DomeView : a tool for digital planetariums
The content produced for fulldome projection is usually made in a frame (the master) with a format corresponding
to a projection of the dome on a plane, commonly the fisheye projection. Due to the distortions involved, looking
at the master does not give a clear idea of the final result once projectedon a planetarium dome. The common
solution when creating and composing content is to go through an iterative process, making successive projections
on a planetarium until the desired result is achieved. However, repeatedaccess to a planetarium is difficult, costly,
and time consuming. So there is a need for an application that can provide theuser with a clear notion of the
final result in the planetarium. In addition, if the application could be used to show content in a small (single
projector) planetarium, like a portable one, its versatility would increase substantially. This paper reports on such
an application: Domeview
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
Neurologic Paraneoplastic Syndromes
Algumas síndromes neurológicas estão ocasionalmente associadas ao cancro sistémico, na forma de síndrome paraneoplásica. Destas, a degenerescência cerebelosa subaguda, neuronopatia
sensitiva, dermatomiosite polimiosite, síndrome miasténica de Eaton-Lambert e neuronopatia motora subaguda tornam obrigatória uma investigação exaustiva, no sentido de identificar o tumor primitivo, devido à sua forte correlação com neoplasia oculta.Os AA apresentam uma revisão
sumária destas síndromes, ilustrando as três primeiras com casos clínicos. Faz-se referência aos aspectos imunológicos associados e à sua importância na caracterização destas entidades
Metals recovery from spent Zn-MnO2 batteries by Hydrometallurgy
A hydrometallurgical process for recycling spent Zn-MnO2 batteries was developed, involving leaching with sulfuric acid, purification by precipitation and metals separation for further recovery. Leaching of zinc oxide was easily attained while for manganese oxide was rather difficult depending on temperature and acid concentration. At 90ºC and with the liquid/solid ratio of 20 L/kg, more than 95% of zinc is recovered in 30 minutes with 0.5M H2SO4. To attain similar recovery for manganese, higher levels of acid concentration and time are needed (e.g 0.7 M and 2 hours). After leaching a purification step is necessary to remove iron co-dissolved through Fe(III) precipitation. Separation of zinc from manganese by solvent extraction with 1M DEHPA follows in the process route. The countercurrent multistage separation diagram developed allows the production of a zinc electrolyte with 120 g/L Zn and 0.005 g/L Mn, and a raffinate with 16 g/L Mn and 0.013 g/L Zn
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