1,184 research outputs found

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

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    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

    Inteligência artificial aplicada à predicação do ponto de abate de bovinos confinados.

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    O objetivo deste trabalho foi criar um software para realizar a predição do ponto de abate de bovinos por meio de características e medidas ultrassonográficas obtidas apenas no início do confinamento

    Numerical Thermal Analysis of a T Jump System Used for Studying Polymer Behaviour

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    Acknowledgements: The authors would like to acknowledge the financial support from Fundação da Ciência e Tecnologia (Portugal) as part of the UC4EP (Understanding Crystallisation for Enhanced Polymer Properties) at CDRSP PTDC/CTM-POL/7133/2014, UID/Multi/04044/2013, PAMI Nº 022158 and the Fundo Europeu de Desenvolvimento Regional (FEDER), Programa Portugal 2020, through the Programa Operacional Regional do Centro 2020 (CENTRO-01-0145-FEDER-022158). The neutron scattering measurement was performed at the STFC ISIS facilities (United Kingdom).The processing of polymers is highly complex. The study of their crystallisation assumes an important role and needs to be carefully detailed. Scattering experiments can be used to study polymer molecular organisation. However these procedures are still very multifaceted leading to the need for planning all the details in the experiments that are to be performed. This manuscript presents a finite element model developed to study the temperature variation of a T Jump System, which has been used for studying polymer behaviour with the NIMROD instrument at the ISIS Neutron and Muon Source, UK. Results show that the variation across the sample was 2ºC at a maximum temperature of 70ºC and 1ºC at a maximum temperature of 50ºC.info:eu-repo/semantics/publishedVersio

    Ethnography and learning in practice: exploring pathways from the case of soccer in Brazil

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    This study presents reflections developed while conducting research on learning in different social practice settings. The common framework that allowed the dialogue between different studies and empirical contexts has drawn from Jean Lave’s learning approach (1991; 2011) in dialogue with authors such as Gregory Bateson (1972) and Tim Ingold (2000). The practices investigated are marked by their singularity regarding fields that characterize the Brazilian society, such as soccer, Afro–Brazilian religions, and indigenous traditional practices. All investigations focused on practices in their diverse configurations in different settings, which nearly always includes the school, which is resituated from the viewpoint of the practice under research. Some recurring aspects suggested that cultural learning may be considered a research subject that crosses disciplinary boundaries and reveals unexpected facets of practices that mark the contemporary scenario of Brazil. The article specifically discusses conceptual and methodological reflections in a double movement: focusing on relevant and common aspects that emerged in the analysis, especially that of the emblematic case of soccer, the learning of which is widespread in Brazil; and repositioning ethnography as a basis for conducting such task, thus producing reflections on ethnographic practice.O artigo propõe apresentar reflexões e questões construídas na condução de pesquisas a respeito do tema da aprendizagem em contextos de práticas sociais diversificadas. A orientação comum que permitiu o confronto entre os diferentes trabalhos e contextos empíricos foi construída a partir da abordagem da aprendizagem situada de Jean Lave (1991, 2011), em diálogo com autores como Gregory Bateson (1972) e Tim Ingold (2000). Os contextos investigados caracterizam-se pela singularidade em relação a temas próprios da sociedade brasileira, tais como o futebol, as religiões afro-brasileiras, práticas tradicionais indígenas, dentre outras. Em todas as investigações, o eixo condutor foi a prática em suas diversas configurações – o que quase sempre inclui a escola, que é, no entanto, ressituada a partir do ponto de vista da prática focalizada na investigação. Alguns aspectos recorrentes indicaram a possibilidade de se pensar na aprendizagem da cultura como tema de pesquisa que atravessa fronteiras disciplinares e que permite revelar facetas inusitadas de práticas que marcam a paisagem do Brasil contemporâneo. Como recorte, o artigo discute as reflexões de caráter conceitual-metodológico que as investigações permitiram realizar a partir de um duplo movimento: focalizando aspectos relevantes que emergiram nas investigações (sobretudo a partir do caso emblemático do futebol, cuja aprendizagem é amplamente difundida no Brasil); e produzindo reflexões acerca da prática etnográfica, ao recolocar a etnografia como fundamento para a realização de tal empreitada

    ARch4maps: A mobile augmented reality tool to enrich paper maps

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    This paper describes an augmented reality app running on a Windows tablet that recognizes image features on a city paper map and overlays, in real-time, digital content related to the relevant buildings of the city. The system register in 3D the location of those buildings in the map, enriching the user experience with several multimedia information per building: image, text and 3D models which can be explored in detail in an included BIM viewer. Displayed buildings can be queried and filtered by associated meta-data such as decade, author, conservation, etc. The main target users of this system are tourists or users interested in architecture or history. Our usability evaluation study conducted with several users shown that our app increase the scope of applicability of a paper map.info:eu-repo/semantics/publishedVersio

    Experimental assessment of the performance of two marine coatings to curb biofilm formation of microfoulers

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    Biofilms formed on submerged marine surfaces play a critical role in the fouling process, causing increased fuel consumption, corrosion, and high maintenance costs. Thus, marine biofouling is a major issue and motivates the development of antifouling coatings. In this study, the performance of two commercial marine coatings, a foul-release silicone-based paint (SilRef) and an epoxy resin (EpoRef), was evaluated regarding their abilities to prevent biofilm formation by Cyanobium sp. and Pseudoalteromonas tunicata (common microfoulers). Biofilms were developed under defined hydrodynamic conditions to simulate marine settings, and the number of biofilm cells, wet weight, and thickness were monitored for 7 weeks. The biofilm structure was analyzed by confocal laser scanning microscopy (CLSM) at the end-point. Results demonstrated that EpoRef surfaces were effective in inhibiting biofilm formation at initial stages (until day 28), while SilRef surfaces showed high efficacy in decreasing biofilm formation during maturation (from day 35 onwards). Wet weight and thickness analysis, as well as CLSM data, indicate that SilRef surfaces were less prone to biofilm formation than EpoRef surfaces. Furthermore, the efficacy of SilRef surfaces may be dependent on the fouling microorganism, while the performance of EpoRef was strongly influenced by a combined effect of surface and microorganism.This research was funded by Base Funding - UIDB/00511/2020 of the Laboratory for Process Engineering, Environment, Biotechnology, and Energy - LEPABE - funded by national funds through the FCT/MCTES (PIDDAC), “CVMAR+i - Industrial Innovation and Marine Biotechnology Valorization” project, funded by INTERREG V Espanha Portugal (POCTEP) (0302_CVMAR_I_1_P), and UIDB/04423/2020 and UIDP/04423/2020 (CIIMAR). The research work was also supported by UIDB/04046/2020 and UIDP/04046/2020 research units grants, Portugal (to BioISI). R.T.-S. thanks the receipt of a junior researcher fellowship from the Project PTDC/BII-BIO/29589/2017 POCI-01-0145-FEDER-029589 funded by FEDER funds through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES. L.C.G. thanks the Portuguese Foundation for Science and Technology (FCT) for the financial support of her work contract through the Scientific Employment Stimulus-Individual Call-[CEECIND/01700/2017]. Atomic force microscopy technique was performed at the Biointerface and Nanotechnology i3S Scientific Platform with the assistance of Manuela Brás

    Traffic Vertical Signposting: Materials Characterization and Structural Numerical Simulation

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    Aknowlegements: This work was supported by the project POCI-01-0247-FEDER-010797from the Agency for Competitiveness and Innovation (IAPMEI). In addition, the authors acknowledge the funding from the project UID/Multi/04044/2013 of the Portuguese Foundation for Science and Technology (FCT) and PAMI - ROTEIRO/0328/2013 (Nº 022158).The existing metallic solutions used for vertical traffic signs are associated with higher costs and environmental issues due to their manufacturing and degradation, when compared with polymeric solutions. Thus, the development of vertical signs considering the injection from polymeric materials in order to overcome problems related with sustainability, maintenance costs, and to achieve higher resistance to corrosion assumes nowadays an important role. The use of ecofriendly and innovative products considering the industrial waste combined with synthetic polymers performing the appropriate mechanical properties, can also be studied to find out new solutions that allow to solve the aforementioned problems. Additionally, these innovative vertical signs can contribute to avoid vandalism events related with theft and graffiti activities. This work presents the prior materials investigation and the structural design of vertical signs that are intended to be produced through polymer injection. Three main steps were considered: i) materials research, ii) materials characterisation through the analysis of polycarbonate resin isolated and in different sets of mixtures with different concentrations through tensile testing and static water contact angle measurements to find the optimal material composition; and iii) structural numerical simulation considering polycarbonate resin and using the current standard EN 12899-1 [1] to compute wind resistance, temporary and permanent deflections. Both experimental and numerical results led to an optimized proposal of the vertical signposting structural design.info:eu-repo/semantics/publishedVersio

    Diffusivities of linear unsaturated ketones and aldehydes in compressed liquid ethanol

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    For the accurate design, optimization and simulation of chemical processes limited by mass transfer kinetics it is important the knowledge of transport properties, namely, diffusion coefficients, D12. In this work, the D12 values of six unsaturated linear ketones (i.e., propanone, butanone, propan-2-one, propan-3-one, hexan-2-one and hexan-3-one) and three unsaturated linear aldehydes (i.e., butanal, pentanal and hexanal) in (compressed) liquid ethanol were measured at temperatures from 303.15 K to 333.15 K and pressures up to 150 bar. The D12 values of ketones are in the range of 1.28 × 10−5 – 2.89 × 10−5 cm2 s−1 and of the aldehydes are between 1.39 × 10−5 and 2.68 × 10−5 cm2 s−1. The general trends of D12 regarding temperature, pressure, Stokes-Einstein coordinate, and free volume are presented and discussed. The diffusivities of the various ketones position isomers and aldehyde/ketone isomers were statistically compared, being possible to conclude that the former ones exhibit indistinguishable diffusivities while different values appear for aldehydes/ketones isomers. Finally, five models and a machine learning algorithm from the literature were tested to predict/correlate the new data. It is suggested that the TLSM model should be the preferred approach for D12 prediction of linear unsaturated aldehydes and ketones in liquid compressed ethanol.publishe
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