739 research outputs found

    Species richness and biomass of understory vegetation in a Eucalyptus globulus Labill. coppice as affected by slash management

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    The aim of this study was to assess the effect of different slash management practices on understory biodiversity and biomass in Eucalyptus globulus coppices in Central Portugal. The experiment consisted of four treatments: (a) removal of slash (R), (b) broadcast over the soil (S), (c) as in S but concentrating woody residues between tree rows (W) and (d) incorporation of slash into soil by harrowing (I). Understory vegetation was surveyed during 1–6, 9, and 10 years, the proportion of soil cover by plant species estimated, and diversity and equitability indexes determined. Above ground understory biomass was sampled in years 2–6, 9, and 10. The highest number of species in most years occurred in plots where slash was removed. Differences between treatments in the proportion of plant soil cover were never significant, whereas differences in diversity index were only occasionally significant and apparently related to the number of species. Thus, differences in the equitability index were not significant. Understory biomass did not decrease during the rotation period, and was usually highest in R and I, and lowest in S, but not significantly different. At the end of the rotation period, understory biodiversity indices and biomass were apparently independent of slash treatment

    Uma tipografia de base elíptica e outros cruzamentos do design com a geometria das curvas cónicas

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    Através de alguns exemplos práticos, pretende-se defender que o conhecimento geométrico e, em particular, o conhecimento das curvas cónicas e suas aplicações, pode potenciar o trabalho projetual dos designers, diminuir os custos de hardware e software no ensino e no trabalho profissional, diminuir a necessidade de recurso a meios sofisticados e caros, reduzir a necessidade de permanente atualização dos meios tecnológicos, e de utilização de software que implique formação especializada e, sobretudo, que necessite de longos períodos de formação. Temos em vista contribuir para o reconhecimento da importância do estudo destas curvas e das superfícies por elas geradas, em especial no ensino da Geometria em cursos de Design. De facto, a partir da sistematização do conhecimento existente em outras áreas, como, por exemplo, a arquitetura e as engenharias, pelo aprofundamento da adaptação de propriedades das cónicas e de conhecimentos de áreas, como a geometria analítica ou a projetiva para a linguagem dos traçados geométricos, e pela contribuição com a sugestão de novos traçados, pode desenvolver-se a capacidade dos designers e estudantes de design resolverem problemas, no âmbito do projeto, na representação técnica e na comunicação externa com não peritos.Through some examples, we intend to argue that the knowledge of geometry and, in particular, the knowledge of conic curves and their applications, may potentiate the project work of designers, reducing the costs of hardware and software in teaching and professional work, reducing also the need for sophisticated and expensive means, and its continuous updating, and the use of software which involves specialized training, and especially requiring long training periods. We want to contribute to the recognition of the importance of the study of these curves and surfaces generated by them, especially in the teaching of Geometry in Design courses. In fact, from the systematization of existing knowledge in other areas, such as architecture and engineering, developing the adaptation of properties of conic curves and also the knowledge of areas such as analytic or projective geometry to the geometric design and contributing by suggesting new ways to draw the curves, we can develop the ability of designers and design students to solve problems in the context of the project, and others such as technical representation and external communication with non-experts

    Biomedical data management and processing - a new framework

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    The integration of information from biomedical devices is of fundamental importance for effective medical diagnosis. In this sense, the present work aimed to develop a new framework able to manage and process biomedical data in real time. The major advantage of the proposed solution is the ability to add new medical devices and integrate their results with the existing ones. The devices tested include brainwave sensors, a baropodometric treadmill and a biomedical kit composed of a patient position sensor (accelerometer), glucometer, body temperature, blood pressure, pulse and oxygen in blood, airflow, galvanic skin response and electrocardiogram sensors. From the tests conducted, it can be concluded that the proposed framework is robust, accurate and fast, and can manage and process large volumes of data in real time. Customizable graphs can be built from the electroencephalogramsignals acquired during patient gait, which can be analyzed based on barographic image registration. Finally, it can be concluded that the framework is quite promising to be used to assist medical diagnosis and improve and accelerate the treatment of patients

    Utilização de nanopartículas de TIO2 para o desenvolvimento de pavimentos rodoviários com capacidade fotocatalítica

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    A utilização de nanomateriais na indústria de construção rodoviária representa uma opção estrategicamente inovadora que visa a modificação dos materiais convencionais. Neste âmbito, dotar a superfície dos pavimentos rodoviários de capacidade fotocatalítica contribuirá para efetuar a despoluição do ar e a redução da sujidade adsorvida nestas superfícies, aumentando a segurança rodoviária uma vez que minimiza a presença de óleos e gorduras adsorvidos pelas mesmas. Neste trabalho, misturas asfálticas convencionais foram modificadas pela adição de nanopartículas de TiO2 através de dois processos diferentes: inclusão em volume e por aspersão superficial de uma solução aquosa de nanopartículas de TiO2. As misturas asfálticas foram caracterizadas quimicamente e a sua morfologia e capacidade fotocatalítica foram avaliadas. Os resultados obtidos demonstram que a utilização de nanopartículas de TiO2 (aplicadas na superfície pela técnica de aspersão) permitiu obter misturas asfálticas com elevada capacidade fotocatalítica, já que o rendimento de fotodegradação foi superior a 50%.FEDE

    Carbon footprint of apple and pear: orchards, storage and distribution

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    Apple and pear represent 51% of fresh fruit orchards in Portugal. This paper presents a life-cycle (LC) greenhouse gas (GHG) assessment (so-called carbon footprint) of 3 apple and 1 pear Portuguese production systems. An LC model and inventory were implemented, encompassing the farm stage (cultivation of fruit trees in orchards), storage and distribution (transport to retail). The functional unit considered in this study was 1 kg of distributed fruit (at retail). Four different LC inventories for orchards were implemented based on data collected from three farms. Inventory data from two storage companies were also gathered. The main results show that the GHG emissions of apple and pear ranged between 192 and 229 gCO2eq kgfruit-1. The GHG emissions (direct and indirect) from the cultivation phase ranged from 36% to 60% of total emissions. Fruit storage, which lasted for as much as 8-10 months, was also responsible for significant emissions due to high energy requirements.Project ECODEEP (Eco-efficiency and Eco-management in the Agro Industrial sector, FCOMP–05–0128–FEDER–018643) and the Portuguese Science and Technology Foundation projects: MIT/SET/0014/2009, PTDC/SEN-TRA/117251/201

    Anomalous specific heat in high-density QED and QCD

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    Long-range quasi-static gauge-boson interactions lead to anomalous (non-Fermi-liquid) behavior of the specific heat in the low-temperature limit of an electron or quark gas with a leading TlnT1T\ln T^{-1} term. We obtain perturbative results beyond the leading log approximation and find that dynamical screening gives rise to a low-temperature series involving also anomalous fractional powers T(3+2n)/3T^{(3+2n)/3}. We determine their coefficients in perturbation theory up to and including order T7/3T^{7/3} and compare with exact numerical results obtained in the large-NfN_f limit of QED and QCD.Comment: REVTEX4, 6 pages, 2 figures; v2: minor improvements, references added; v3: factor of 2 error in the T^(7/3) coefficient corrected and plots update

    Life-cycle greenhouse gas emissions of portuguese olive oil

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    The main goal of this paper was to assess the greenhouse gas (GHG) intensity of olive oil production in Portugal. A life-cycle model and inventory were implemented for the entire production process, including a comprehensive analysis of olive cultivation, olive oil extraction, packaging, and distribution. Data originates from five differently-sized Portuguese olive growers and from a total of six olive oil mills, representing the three extraction processes in use: three-phase extraction, two-phase extraction, and traditional pressing. The results show that the GHG intensity lies in the range 1.8-8.2 kg CO2eq/liter and that the main contributors were fertilizers (production and field emissions). Efficient use of fertilizers thus seems to be a key factor for mitigating the GHG intensity of olive oil production

    Photocatalytic degradation of Rhodamine B dye by cotton textile coated with SiO2-TiO2 and SiO2-TiO2-HY composites

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    This work is devoted to study the photocatalytic ability of cotton textiles functionalized with SiO2-TiO2 and SiO2-TiO2-HY composites to degrade a dye molecule. Coatings were prepared by sol-gel method and calcined at different temperatures in a range of 400–750 °C. FTIR confirmed the existence of SiOTi bounds and the band located in the region between 570 and 600 cm−1 was used to calculate the framework Si/Al ratio of HY in the SiO2-TiO2-HY composites. XRD confirmed the presence of nanosized TiO2 (anatase phase) in all calcined composites. Nitrogen adsorption isotherms showed a decrease in surface area and pore volume for higher calcination temperature. A simple mechanical process was used to impregnate the different composites on the cotton substrates. The photocatalytic activity of cotton textiles functionalized with SiO2-TiO2 and SiO2-TiO2-HY composites was tested via the degradation of Rhodamine B (RhB) dye under similar solar irradiation. The best catalytic performance was achieved with the SiO2-TiO2 and SiO2-TiO2-HY composites subjected to a calcination treatment at 400 °C, whereas SiO2-TiO2 presented a decolourization and mineralization around 94% and 89%, respectively, after 2 h of irradiation. Furthermore, the products of RhB degradation were analysed and identified by using HPLC-ESI–MS and ion chromatography techniques and a photocatalytic mechanism was proposed.The authors thank CAPES from Brazil for the financial support of this work. This work is also a result of project “AIProcMat@N2020 − Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE-01-0145-FEDER-000006 and the project BioTecNorte (operation NORTE-01-0145-FEDER-000004), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work also has been funded by ERDF through COMPETE2020 − Programa Operacional Competitividade e Internacionalização (POCI), Project POCI-01-0145-FEDER-006984 − Associate Laboratory LSRE-LCM and by national funds through FCT − Fundacão para a Ciência e a Tecnologia for project PTDC/AAGTEC/5269/2014 and Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016).info:eu-repo/semantics/publishedVersio

    Photocatalysis of functionalised 3D printed cementitious materials

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    The main objective of this study was to evaluate the photocatalytic behaviour of 3D printed cementitious mortars that were functionalised with TiO2 nanoparticles. This study is one of the few available regarding functionalisation of 3D concrete printing (3DCP) with photocatalytic properties. Despite the fact 3DCP research is swiftly growing, it is still necessary further investigation to fully understand these materials’ physicochemical and mechanical properties, which will influence the functionalised properties of the composite. Due to the freeform nature of the 3DCP there are no moulds, therefore the functionalisation through coating can be performed in a much earlier stage than in conventional moulded concrete. The developed smart 3D printed concrete could promote the photodegradation of pollutants for self-cleaning and air purification. In particular, this study investigated the effect of two parameters on photocatalytic behaviour: light power intensity and the coating rate of nano-TiO2 particles. Surface coating was adopted as the functionalisation method, and the Rhodamine B dye degradation efficiency was used as an indicator to evaluate the photocatalytic behaviour. Additionally, the surface roughness and microstructure of the 3D printed cementitious mortar specimens were assessed to distinguish between the reference and TiO2 coated series. Scanning electron microscopy (SEM), X-ray Energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) crystallography were carried out as three techniques to evaluate the morphology, composition, and microstructure of the specimens, respectively. The results indicated successful activation of catalyst particles under illumination, where higher light power intensity increased the degradation efficiency. Furthermore, dye degradation efficiency increased with increasing coating rates of nano-TiO2 particles on the surface of the specimens. The roughness of the 3D printed specimens’ surface was sufficient for settling the nano-TiO2 particles. Finally, microscopy results confirmed the presence and suitable distribution of the nano-TiO2 particles on the surface of the coated specimens.Support SECIL, SIKA, ELKEM and UNIBETAO, which graciously provided the required materials for printing the cementitious specimensThis work was partly financed by Fundaç˜ao para a Ciˆencia e a Tecnologia (FCT)/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020. The authors acknowledge the support of DST group construction company for funding the project Chair dst/IB-S: Smart Systems for Construction. The first two authors would like to acknowledge the PhD grants SFRH/BD/143636/2019 and SFRH/BD/137421/2018 provided by the Portuguese Foundation for Science and Technology (FCT). Additionally, the authors would like to acknowledge FCT for the financing this research work by the project NanoAir PTDC/FIS-MAC/6606/2020 and the Strategic Funding UIDB/04650/ 2020–2023
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