13 research outputs found

    PARTICLEBOARDS OF AGROINDUSTRIAL WASTES

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    O presente trabalho teve como objetivo desenvolver pain\ue9is de part\uedculas aglomeradas de baixa densidade com casca de amendoim, fibra da casca do coco-verde (h\uedbrido) e resina poliuretana bicomponente \ue0 base de \uf3leo de mamona. Os pain\ue9is experimentais foram fabricados com part\uedculas de at\ue9 8 mm de comprimento e 15% de resina poliuretana. A prensagem foi realizada a 5,0 MPa, por 10 minutos, a uma temperatura de 100\ub0C. Foram determinadas as propriedades f\uedsico-mec\ue2nicas do material, seguindo as recomenda\ue7\uf5es da norma ABNT 14810:2006. Os resultados demonstraram que o desempenho mec\ue2nico que atende \ue0s recomenda\ue7\uf5es estabelecidas pela normativa ANSI A208.1-1999 e ABNT 14.810-2:2006.The present study aimed to develop particleboards of low density with peanut shell, coconut husk fiber green (hybrid) and two-component polyurethane resin based on castor oil. The experimental panels were manufactured with particles up to 8mm and 15% polyurethane resin. The pressing was carried out at 5.0 MPa for 10 minutes at 100\ub0C of temperature. The physical-mechanical properties of the material were determined as recommended by ABNT 14810:2006. The results demonstrated a mechanical performance that meets the recommendations established by normative ANSI A208.1-1999 and ABNT 14.810-2:2006

    PAINEL AGLOMERADO DE RESÍDUOS AGROINDUSTRIAIS

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    The present study aimed to develop particleboards of low density with peanut shell, coconut husk fiber green (hybrid) and two-component polyurethane resin based on castor oil. The experimental panels were manufactured with particles up to 8mm and 15% polyurethane resin. The pressing was carried out at 5.0 MPa for 10 minutes at 100°C of temperature. The physical-mechanical properties of the material were determined as recommended by ABNT 14810:2006. The results demonstrated a mechanical performance that meets the recommendations established by normative ANSI A208.1-1999 and ABNT 14.810-2:2006.http://dx.doi.org/10.5902/1980509819675O presente trabalho teve como objetivo desenvolver painéis de partículas aglomeradas de baixa densidade com casca de amendoim, fibra da casca do coco-verde (híbrido) e resina poliuretana bicomponente à base de óleo de mamona. Os painéis experimentais foram fabricados com partículas de até 8 mm de comprimento e 15% de resina poliuretana. A prensagem foi realizada a 5,0 MPa, por 10 minutos, a uma temperatura de 100°C. Foram determinadas as propriedades físico-mecânicas do material, seguindo as recomendações da norma ABNT 14810:2006. Os resultados demonstraram desempenho mecânico que atende às recomendações estabelecidas pela normativa ANSI A208.1-1999 e ABNT 14.810-2:2006

    Pervasive gaps in Amazonian ecological research

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    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

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    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost

    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 understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost

    Composite particles with low density peanut shell, coconut fiber and castor oil polyurethane resin for application as castor lining of poultry houses

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    O presente trabalho considerou o potencial de utilização de resíduos da agroindústria como a casca de amendoim e fibra de coco verde com o intuito de agregar valor a este material, por meio da fabricação de compósito particulado de baixa densidade para uso como forro de galpões avícolas. Para a confecção do compósito foi utilizado à casca de amendoim, fibra de coco verde e resina poliuretana bi-componente à base de óleo de mamona. O material foi avaliado por meio de ensaios físico-mecânicos: a) densidade, b) inchamento, c) absorção, d) módulo de ruptura, e) módulo de elasticidade e f) adesão interna; durabilidade: a) envelhecimento natural e b) envelhecimento acelerado; térmicos: a) condutividade térmica; b) fator de ganho de calor solar. Considerando os resultados obtidos nessa pesquisa, conclui-se que o compósito apresentou propriedades físico-mecânicas compatíveis com as necessidades de uso do material. Os ensaios de durabilidade demonstraram que as propriedades mecânicas do compósito são reduzidas após aplicação de ciclos de umidade e temperatura, no entanto, essa avaliação foi rigorosa e não representa as condições reais de exposição do compósito, em uso como forro de galpões avícolas. O contato prolongado com fontes de umidade acarretou o desenvolvimento de fungos no material, evidenciando a necessidade de aplicação de produto impermeabilizante na superfície do material, para reduzir a absorção de água. Pelo ensaio de condutividade térmica foi possível determinar o fator de ganho de calor solar o qual demonstrou que quando o compósito é aplicado como forro, ocorre uma redução significativa da transferência de radiação solar para o interior do aviário, comprovando o potencial do material para esse uso.This study considered the potential use of agro waste like peanut hulls and coconut fiber in order to add value to this material through the manufacturing of composite particles of low-density liner for use as poultry houses. To make the composite was used for peanut shell, coconut fiber and bi-component polyurethane resin-based castor oil. The material was evaluated by physical-mechanical tests: a) density, b) swelling, c) absorbing, d) modulus of rupture, e) elastic modulus and f) internal adhesion, durability: a) natural aging b) Accelerated aging ; thermal: a) thermal conductivity b) factor of solar heat gain. Considering the results obtained in this study, it is concluded that the composite possess physical and mechanical properties compatible with the needs of use of the material. Durability testing showed that the mechanical properties of the composite are reduced after application of cycles of humidity and temperature, however, the evaluation was rigorous and does not represent the actual conditions of exposure of the composite in lining use as poultry houses. Prolonged contact with sources of moisture caused fungal growth in the material, indicating the need for application of sealer to the surface of the material, to reduce water absorption. For the thermal conductivity test was possible to determine the factor of solar heat gain which demonstrated that when the composite is applied as a lining, there is a significant reduction in the transfer of solar radiation into the poultry, demonstrating the potential of this material for use

    Particleborads of cement bag and long-life packaging applied as lining in avian prototypes

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    No presente trabalho, considerou o estudo do potencial de utilização de sacos de cimento e embalagens de longa vida com o intuito de agregar valor a esses resíduos, mediante a fabricação de painéis de partículas para uso como forro em protótipos de galpões avícolas. Para fabricação desse material foi utilizado sacos de cimento descartados nas obras civis, embalagens longa vida residuais e resina poliuretana bicomponente à base de óleo de mamona. O estudo foi dividido em quatro etapas: 1) Caracterização da matéria-prima (sacos de cimento); 2) Efeito da densidade e teor de resina nas propriedades físicas, mecânicas e térmicas de painéis de partículas de saco de cimento; 3) Avaliação do desempenho de embalagens longa vida e verniz como revestimentos dos painéis selecionados na etapa anterior; 4) Determinação do desempenho térmico de protótipos de aviários executados em escala reduzida e distorcida com forro de painel de saco de cimento e embalagem longa vida. Os resultados obtidos indicaram: Em razão do painel com 0,6 g.cm-3 e 12% de resina ter apresentado melhor desempenho nas propriedades investigadas, essa combinação foi selecionada para avaliar o desempenho do material (físicas, mecânicas e térmicas) quando revestido com embalagens longa vida, adotando a testemunha e o verniz como um revestimento comparativo. Dentre os revestimentos avaliados, os painéis com embalagens de longa vida, foram superiores aos revestidos com verniz, quando comparados as suas propriedades físicas, mecânicas e térmicas. Dessa maneira, painéis com 0,6 g.cm-3 e 12% de resina revestidos embalagens longa vida, foram testados como forro quanto ao desempenho térmico (primavera, verão, outono e inverno) em protótipos em escala reduzida e distorcida, mediante a determinação de índices de conforto térmico (Entalpia e IAPfc) para aves de corte. A associação do forro sob o protótipo permitiu reduzir a temperatura interna do ar e dos índices de conforto térmico na primavera, verão e outono, enquanto que no inverno não foi constatado eficácia do material. Dentre as estações estudadas, o verão e a primavera, demonstraram serem as épocas mais críticas para criação de aves corte em instalações avícolas que apresentem características semelhantes aos protótipos experimentais.In this study, the study of the potential use of cement bags and long-life packaging is considered in order to add value to this waste, by manufacturing particleboards as insulating panels in poultry house facilities. For the production of this material cement bags discarded in civil works, long-life packaging discarded by consumers and two-component polyurethane resin based on castor oil base were used. The study was structured in four steps: 1) Characterization of the raw material (cement bags), 2) Effect of the density and the level of resin on the physical, mechanical and thermal properties of cement particles bag panels, 3) Evaluation of long-life packaging and varnish as a coating of selected panels in precedent step and 4) Evaluation of thermal performance of poultry prototypes in reduced and distorted scale with the long-life packaging as a coating material. The cement bags were disintegrated and transformed into particles with the 8% of moisture content. Subsequently, these particles were mixed with bicomponent polyurethane based on castor oil resin and taken into a planetary mixer (MT120) in order to homogenize the mixture of the particles with the resin. Panels were made for three different densities (0.4, 0.5 and 0.6 g.cm-3) with two resin levels (12 and 15%) and their physical, mechanical and thermal properties were evaluated. Because the panel with 0.6 g.cm-3 and 12% resin have shown a better performance in the investigated properties, this combination has been selected to evaluate the performance of the material (physical, mechanical and thermal) when coated with long-life packaging, adopting the control and the varnish as a comparative coating. Among the evaluated coatings, panels with long-life packaging, presented higher performance than those coated with varnish regarding their physical, mechanical and thermal properties. Thus, the combination of 0.6 g.cm-3 and 12% resin coated long-life packages were tested as lining according the thermal performance (spring, summer, autumn and winter) in prototypes and small-distorted scale by determining thermal comfort indices (Enthalpy and IAPfc) for broilers. The association of lining under the prototype reduced indoor air temperature and thermal comfort indices in spring, summer and autumn, while during the winter no effectiveness of the material was observed. Among the studied seasons, the spring and summer, proved to be the most critical time for cut birds breeding in poultry houses that have characteristics similar to experimental prototypes

    <b>Modular panel with wood and particleboards of sugarcane bagasse for cattle handling facilities

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    This work aimed at the construction and structural evaluation of modular panel with reforested wood, particleboards of sugarcane bagasse and a bi-component resin based on castor oil, for use in lateral closing for construction of crowding pens and chutes for cattle handling facilities. The quality of the particleboards was evaluated considering the requirements of NBR 14810 (ABNT, 2006) and A208.1 (ANSI, 1999). The structural performance of the modular panel was evaluated by the soft body impact testing. The results indicate that the particleboards have physical and mechanical properties that meet the minimum recommendations of the normative documents for structural use. The modular panel shows structural performance suitable to withstand impact loads equivalent to conditions of use, and can be used in cattle handling facilities
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