72 research outputs found

    CARACTERĂŤSTICAS TECNOLĂ“GICAS DAS MADEIRAS DE Eucalyptus grandis W.Hill ex Maiden E Eucalyptus cloeziana F. Muell VISANDO AO SEU APROVEITAMENTO NA INDĂšSTRIA MOVELEIRA

    Get PDF
    Este trabalho se desenvolveu na Universidade de Brasília e no Laboratório de Produtos Florestais (IBAMA), Brasília, DF. Foram estudadas duas espécies de eucalipto (Eucalyptus grandis W.Hill ex Maiden e Eucalyptus cloeziana) para confecção de peças mobiliárias. A madeira de E. grandis apresenta propriedades físicas (densidade e retratibilidade) e mecânicas (flexão estática e dureza) extremamente positivas para a indústria moveleira, sendo complementado por seu bom desempenho perante equipamentos e máquinas, além de receber bem produtos de acabamento. A cor da madeira e o seu desenho levaram os consumidores a mostrar ótima aceitação do móvel fabricado com a espécie. A madeira de Eucalyptus cloeziana, apesar de mostrar propriedades físicas e mecânicas com valores mais elevados que as do Eucalyptus grandis W.Hill ex Maiden, apresenta características desejadas para indústria moveleira. A sua coloração cinza oliva é uma opção para o consumidor. Alguns cuidados especiais com essa espécie deverão ser tomados durante operações com máquinas e equipamentos. Os valores da propriedade dureza apresentados por essa madeira a indicam para fabricação de piso

    LaMMos - Latching Mechanism based on Motorized-screw for Reconfigurable Robots and Exoskeleton Suits

    Full text link
    Reconfigurable robots refer to a category of robots that their components (individual joints and links) can be assembled in multiple configurations and geometries. Most of existing latching mechanisms are based on physical tools such as hooks, cages or magnets, which limit the payload capacity. Therefore, robots re- quire a latching mechanism which can help to reconfigure itself without sacrificing the payload capability. This paper presents a latching mechanism based on the flexible screw attaching principle. In which, actuators are used to move the robot links and joints while connecting them with a motorized-screw and dis- connecting them by unfastening the screw. The brackets used in our mechanism configuration helps to hold maximum force up to 5000N. The LaMMos - Latching Mechanism based on Motorized- screw has been applied to the DeWaLoP - Developing Water Loss Prevention in-pipe robot. It helps the robot to shrink its body to crawl into the pipe with minimum diameter, by recon- figuring the leg positions. And it helps to recover the legs positions to original status once the robot is inside the pipe. Also, LaMMos add stiffness to the robot legs by dynamically integrate them to the structure. Additionally, we present an application of the LaMMos mechanism to exoskeleton suits, for easing the mo- tors from the joints when carrying heavy weights for long periods of time. This mechanism offers many interesting opportunities for robotics research in terms of functionality, pay- load and size.Comment: 14 pages, 15 figure

    PHYSIOLOGICAL QUALITY OF PROCESSED, REPROCESSED, AND STORED SORGHUM SEEDS: IMPACT OF A DENSIMETRIC TABLE

    Get PDF
    ABSTRACT Sorghum ( Sorghum bicolor L. Moench) is a crop of paramount importance for Brazil, used in human and animal food. Considering the reduced number of studies on the influence of using a densimetric table in seed processing and its respective reprocessing to the equipment, this study aimed to evaluate the physiological quality of processed sorghum seeds reprocessed in a densimetric table and stored for three months. The treatments consisted of four collection points in the terminal part of the densimetric table, representing the processing material: upper part (P1), upper middle part (P2), middle part (P3), and lower part (D). Subsequently, the samples that were reprocessed in the table came from P3 and were divided into the upper part, which was followed to bagging (P3R1), and the lower part (P3R2), which followed for disposal, totaling six treatments. Storage was performed in a refrigerated environment, using a completely randomized design, with the means being compared by Tukey’s test at 5%. We concluded that the reprocessing of sorghum seeds in the densimetric table can improve the physical quality of a lot due to its standardization at the end of the stages, contributing to the improvement of the physiological quality and use of the material that would be discarded. The equipment performance allows the removal of seed fractions with lower apparent specific mass and promotes positive stratifications in the physiological quality of sorghum seed lots

    Technological characteristics of the wood of Eucalyptus grandis W.Hill ex Maiden and Eucalyptus cloeziana F. Muell, as a supply for the furniture industry

    Get PDF
    Este trabalho se desenvolveu na Universidade de Brasília e no Laboratório de Produtos Florestais (IBAMA), Brasília, DF. Foram estudadas duas espécies de eucalipto (Eucalyptus grandis W.Hill ex Maiden e Eucalyptus cloeziana) para confecção de peças mobiliárias. A madeira de E. grandis apresenta propriedades físicas (densidade e retratibilidade) e mecânicas (flexão estática e dureza) extremamente positivas para a indústria moveleira, sendo complementado por seu bom desempenho perante equipamentos e máquinas, além de receber bem produtos de acabamento. A cor da madeira e o seu desenho levaram os consumidores a mostrar ótima aceitação do móvel fabricado com a espécie. A madeira de Eucalyptus cloeziana, apesar de mostrar propriedades físicas e mecânicas com valores mais elevados que as do Eucalyptus grandis W.Hill ex Maiden, apresenta características desejadas para indústria moveleira. A sua coloração cinza oliva é uma opção para o consumidor. Alguns cuidados especiais com essa espécie deverão ser tomados durante operações com máquinas e equipamentos. Os valores da propriedade dureza apresentados por essa madeira a indicam para fabricação de piso.This work was carried out at Universidade de Brasília at the Wood Products of Forestry Laboratory (IBAMA, Brasília, DF, Brazil). Two species of eucalypt wood (Eucalyptus grandis W.Hill ex Maiden and Eucalyptus cloeziana) were studied to supply the furniture making industry. The wood of Eucalyptus grandis W.Hill ex Maiden shows physical properties (density and retractibility) and mechanical properties (static bending and hardness) very suitable for the industry of wood furniture. Such characteristics are complemented by its excellent behaviour in machining and also good finishing with varnishes. The colour and patterns the wood bring to the consumers a good feeling as well as for the furnitures built with such a species. The wood of Eucalyptus cloeziana, in spite of its mechanical and physical properties higher than those of Eucalyptus grandis W.Hill ex Maiden, presents good characteristics for the manufacture of furniture. Its grey-olive colouring is consistent with a good choice and taste for the consumers. However, some precaution must be observed during the machining of the wood. This wood’s hardness makes it suitable for parquetry

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

    Get PDF
    • …
    corecore