1,531 research outputs found

    Use of pulp mill inorganic wastes as alternative liming materials

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    A laboratory aerobic incubation study was performed during 18 weeks under controlled conditions to assess the effects of applying different doses of pulp mill inorganic wastes on the physical–chemical properties of an acid Dystric Cambissol. Three different inorganic wastes were tested – wood ash, dregs and grits, and an agriculture limestone was used as reference. Results showed that increasing the dose applied of the different inorganic wastes tested always led to significant raises of soil pH at different incubation times demonstrating that its use as alternative-liming materials could be a valid and less expensive option to the use of commercial agricultural limestone. Moreover, no immediate concerns seem to be expected related to soil exchangeable sodium (Na) content, at least for the doses needed to increase soil pH until the targeted value 6.5. Particularly for wood ash a pronounced increase on soil extractable potassium and phosphorous was observed, indicating that besides the liming effect this waste can contribute to improve soil fertility by supplying significant available amounts of these nutrients. Finally, metals do not seem to be a limiting factor for the application to land of these byproduct

    Variação da densidade de fluxo de seiva e do potencial hídrico foliar nas faces leste e oeste da copa de laranjeira 'Valência'.

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    O objetivo deste trabalho foi avaliar a influência da variação diurna e sazonal dos fatores ambientais sobre a densidade de fluxo de seiva (DFS) e o potencial hídrico foliar (?f) nas faces leste e oeste da copa de laranjeiras ?Valência? em condições de sequeiro. Foram utilizadas três plantas para as avaliações, cujas linhas de plantio estavam orientadas no sentido norte-sul. As avaliações foram realizadas durante um dia, em cada época do ano: verão, outono, inverno e primavera. Os valores de potencial hídrico medidos antes do amanhecer variaram de -0,31 MPa, no dia 10-12-05, a -1,1 MPa, no dia 30-08-05, porém não houve diferença signifi cativa entre as faces leste e oeste da copa. Já para o potencial hídrico medido às 14h 30, em todas as épocas avaliadas, a face oeste apresentou menores (p<0,05) valores que os da face leste, sendo que os mesmos variaram entre -0,95 e -1,89 MPa, verifi cados nos dias 10-12-05 e 30-08-05, respectivamente. A maior demanda evaporativa que se verifi ca no período da tarde, induz a maior déficit hídrico na face oeste da copa, independentemente da época do ano e, por consequência, maior DFS em plantas bem hidratadas sob condições de dias completamente ensolarados. Em plantas em condições de defi ciência hídrica (indicada por baixos valores de ?f), a face oeste é mais sensível a essa situação, apresentando redução de DFS. Essa redução ocorre no inverno, na região de Cordeirópolis (SP)

    Robotics as a tool to increase the motivation levels in problematic students

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    The study described in this work was done by students of the Training and Education Courses (CEFs) in Informatics Operators of EB 2,3 Gonçalo Sampaio in Póvoa de Lanhoso during the academic year 2008/09. The study was conducted with two classes, with a total of 23 students. These students are aged between 15 and 18 years and the majority are males with only 4 girls. These students were not very motivated to attend school successfully, since they were students that had difficulties and failed one ornmore years. The CEFs were created to allow these students to finish their academic studies, in a less constrained pedagogical environment, that provided access to professional studies

    An MCDM approach to the selection of novel technologies for innovative in-vehicle information systems

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    Driving a car is a complex skill that includes interacting with multiple systems inside the vehicle. Today’s challenge in the automotive industry is to produce innovative In-Vehicle Information Systems (IVIS) that are pleasant to use and satisfy the costumers’ needs while, simultaneously, maintaining the delicate balance of primary task vs. secondary tasks while driving. The authors report a MCDM approach for rank ordering a large heterogeneous set of human-machine interaction technologies; the final set consisted of hundred and one candidates. They measured candidate technologies on eight qualitative criteria that were defined by domain experts, using a group decision-making approach. The main objective was ordering alternatives by their decision score, not the selection of one or a small set of them. The authors’ approach assisted decision makers in exploring the characteristics of the most promising technologies and they focused on analyzing the technologies in the top quartile, as measured by their MCDM model. Further, a clustering analysis of the top quartile revealed the presence of important criteria trade-offs.Operational Competitiveness Program – COMPETE, QREN (Quadro de Referência Estratégico Nacional), European Regional Development Funds (European Union), R&D project in joint-promotion (HMIEXCEL-2013-2015 36265/2013) HMIEXCEL - I&D crítica em torno do ciclo de desenvolvimento e produção de soluções multimédia avançadas para automóvelStrategic program FCT-UID/EEA/00066/2013Fundação para a Ciência e a Tecnologia (IF/00217/2013)Fundação para a Ciência e a Tecnologia (PD/BD/105966/2014

    Omni-directional catadioptric vision for soccer robots

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    This paper describes the design of a multi-part mirror catadioptric vision system and its use for self-localization and detection of relevant objects in soccer robots. The mirror and associated algorithms have been used in robots participating in the middle-size league of RoboCup — The World Cup of Soccer Robots.This work was supported by grant PRAXIS XXI BM/21091/99 of the Portuguese Foundation for Science and Technolog
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