1,432 research outputs found

    The response of smoke detectors to pyrolysis and combustion products from aircraft interior materials

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    The following projects were completed as part of the effort to develop and test economically feasible fire-resistant materials for interior furnishings of aircraft as well as detectors of incipient fires in passenger and cargo compartments: (1) determination of the sensitivity of various contemporary gas and smoke detectors to pyrolysis and combustion products from materials commonly used in aircraft interiors and from materials that may be used in the future, (2) assessment of the environmental limitations to detector sensitivity and reliability. The tests were conducted on three groups of materials by exposure to the following three sources of exposure: radiant and Meeker burner flame, heated coil, and radiant source only. The first test series used radiant heat and flame exposures on easily obtainable test materials. Next, four materials were selected from the first group and exposed to an incandescent coil to provide the conditions for smoldering combustion. Finally, radiant heat exposures were used on advanced materials that are not readily available

    On the connection of Gamma-rays, Dark Matter and Higgs searches at LHC

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    Motivated by the upcoming Higgs analyzes we investigate the importance of the complementarity of the Higgs boson chase on the low mass WIMP search in direct detection experiments and the gamma-ray emission from the Galactic Center measured by the Fermi-LAT telescope in the context of the SU(3)cSU(3)LU(1)NSU(3)_c\otimes SU(3)_L\otimes U(1)_N. We obtain the relic abundance, thermal cross section, the WIMP-nucleon cross section in the low mass regime and network them with the branching ratios of the Higgs boson in the model. We conclude that the Higgs boson search has a profound connection to the dark matter problem in our model, in particular for the case that (MWIMP<60M_{WIMP} < 60 GeV) the BR(H2H \rightarrow 2 WIMPs) 90\gtrsim 90%. This scenario could explain this plateau of any mild excess regarding the Higgs search as well as explain the gamma-ray emission from the galactic center through the bbˉb\bar{b} channel with a WIMP in the mass range of 25-45 GeV, while still being consistent with the current limits from XENON100 and CDMSII. However, if the recent modest excesses measured at LHC and TEVATRON are confirmed and consistent with a standard model Higgs boson this would imply that MWIMP>60 M_{WIMP} > 60 GeV, consequently ruling out any attempt to explain the Fermi-LAT observations.Comment: 8 pages, 9 figure

    Physical properties of Brazil nuts.

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    The Brazil-nut, also known as Para-nut, is widely used as food and in cosmetic industries. The seeds are rich in lipids and protein, and also present a considerable amount of selenium. Limited research has been conducted on postharvest of the Brazil nut, being an important information to design equipment related to aeration, drying, storage and transportation steps. Thus, the objective of this study was to determine the physical properties of the Brazil-nut with and without tegument. The dimensions found for the almonds with tegument were 39.35 mm in the X axis, 24.19 mm in the Y axis, and 17.88 mm in the Z axis. However for the almond without tegument the values were 31.05 mm in X, 14.38 in Y and 15.91 mm in Z axis. The sphericity was 66.40% and 51.59% for the kernels with and without seed tegument respectively. The kernels with and without tegument presented sphericity of 63.00% and 47.72% respectively. The mass of 1000 almonds was 6.13 kg for almond with teguments and 3.18 kg for almonds without teguments. Specific mass of 0.947 g.cm-3 and 1.003 g.cm-3 for the kernels with and without tegument, coupled with a porosity of 46.88% and 37.60% and, resulting on a bulk density of 0.504 g.cm-3 and 0.626 g.cm-3 for almonds with and without teguments respectively. Finally, the angle of repose for the kernels with teguments was 36.37°. A castanha-do-brasil, também conhecida como castanha-do-pará, é muito utilizada na alimentação humana e na indústria cosmética. As sementes são ricas em lipídeos e proteínas, apresentando ainda uma quantidade considerável de Selênio. Poucas pesquisas vêm sendo realizadas na pós-colheita do produto, sendo as propriedades físicas importantes para o desenvolvimento de equipamentos relacionados à aeração, secagem, armazenamento e transporte de produtos. Assim, neste trabalho, teve-se por objetivos: determinar as propriedades físicas da castanha-do-brasil com e sem tegumento. O tamanho para as amêndoas com tegumento, foi de 39,35 mm no eixo X, 24,19 mm no eixo Y e 17,88 mm no eixo Z; já para a amêndoa sem tegumento os valores foram de 31,05 mm em X, 14,38 mm em Y e 15,91 em Z. A esfericidade foi de 66,40% e 51,59%, para as amêndoas com e sem tegumento, respectivamente. 63,00% e 47,72% foram os valores de esfericidade encontrados para as amêndoas com e sem tegumento, respectivamente. A massa de 1.000 amêndoas foi de 6,13 kg para a amêndoa com tegumento e de 3,18 kg para amêndoas sem tegumento. Valores de massa específica de 0,947 g.cm-3 e de 1,003 g.cm-3 para as amêndoas com e sem tegumento, associados a uma porosidade de 46,88% e 37,60%, produziram uma massa específica aparente de 0,504 g.cm-3 e de 0,626 g.cm-3. Finalmente, o ângulo de repouso para as amêndoas com tegumento foi de 36,37°

    Submandibular glands and the regulation of gastric proliferation and TGFα distribution during rat postnatal development

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    Rodent gastric mucosa grows and differentiates during suckling-weaning transition. Among the molecules in rat milk, EGF and TGFβ are important peptides in the control of cell proliferation, and together with TGFα, they are also produced by submandibular glands. We aimed to determine the effect of saliva and milk on epithelial cell proliferation in the stomach of rat pups. We also examined the distribution of TGFα in the gastric mucosa after sialoadenectomy (SIALO) and fasting in order to determine whether this growth factor is affected by the deprivation of molecules derived from saliva and milk. SIALO was performed at 14 days and fasting was induced 3 days later. Cell proliferation was evaluated through metaphasic index and TGFα was detected by immunohistochemistry. We observed that whereas SIALO did not alter cell division, since the metaphasic index (MI) was unchanged, fasting stimulated cell proliferation (P < 0.05). After SIALO and fasting, MI was reduced when compared to the fasted group (P < 0.05). We found that TGFα is distributed along gastric gland and SIALO did not interfere in the localization and number of immunolabeled cells, but fasting increased their density when compared to the control (P < 0.05). The association of SIALO and fasting reduced TGFα immunostaining (P < 0.05). Therefore, during fasting, high MI was parallel to increased TGFα in gastric epithelium, but interestingly, this effect was found only in the presence of submandibular glands. We suggest that during suckling, peptides derived from saliva and milk are important to regulate gastric growth.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Association of slow darkening gene 'SD' with grain quality traits in carioca bean and new candidate marker.

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    The seed darkens during storage becoming less acceptable to consumers and depreciation of the economic value. Cultivars with delayed grain darkening associated with reduced cooking time after storage will be advantageous for the farmer and seed dealers. Grain storage for longer periods allows flexibility, i.e., the producer can await better prices on the market

    Contaminação de aflatoxinas em castanha-do-brasil com casca em sistemas extrativista e de plantio.

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    Diante de problemas de contaminação por aflatoxinas enfrentados na cadeia produtiva da castanha-do-brasil, o objetivo deste trabalho foi estudar o teor de aflatoxinas em castanhas com casca em diferentes etapas dos sistemas de produção: extrativista e de plantio. A produção extrativista consiste na coleta de ouriços recém caídos das árvores e permanecidos no solo por vários dias, empilhamento na floresta, abertura e seleção de castanhas com casca, seguida de armazenamento/secagem sob ventilação durante vários meses. Contudo, no sistema de plantio somente os ouriços com menos de 5 dias no solo são coletados, em seguida são desinfectados com hipoclorito de sódio a 1% e armazenados sob ventilação até abertura e seleção das castanhas com casca. Sessenta amostras de castanha-do-brasil com casca foram coletadas diretamente ou após abertura dos ouriços na região amazônica do Brasil, provenientes da produção extrativista no Acre e do sistema de plantio no Amazonas. As aflatoxinas (B1, B2, G1, G2) foram determinadas por Cromatografia Líquida de Alto Desempenho com detector de fluorescência bem como a atividade de água (aw) nas castanhas descascadas. Nas etapas do sistema extrativista na floresta, dos 33 ouriços coletados, castanhas provenientes de um ouriço com menos de 5 dias de contato com o solo e um ouriço empilhado durante 15 dias apresentaram contaminação por AFB1 inferior a 0,1 µg/kg de matéria fresca (MF). Entretanto o nível de AFB1 variou de 0,6 a 4,4 µg/kg de MF em 3 ouriços com mais de 30 dias em contato com o solo, mais susceptíveis a serem danificados e degradados por condições climáticas e predadores da floresta amazônica. No sistema de plantio, dos 5 ouriços coletados, somente uma amostra proveniente de um ouriço com menos de 5 dias de contato com o solo apresentou contaminação por AFB1, inferior a 0,1 µg/kg de MF. Em armazém ventilado do sistema de plantio, AFB1 foi detectada com teor inferior a 0,1 µg/kg de MF em uma amostra dos 10 ouriços coletados. Todavia no sistema extrativista, os teores de aflatoxinas das castanhas com casca aumentaram e foram superiores ao regulamento europeu (10 µg/kg de MF, UE n°165/2010) ao longo do armazenamento (até 90 dias). A secagem sob ventilação durante o armazenamento não é suficientemente eficaz para atingir rapidamente uma aw inferior a 0,7, evitando o desenvolvimento de fungos aflatoxinogênicos e a produção de aflatoxinas. Resultados sugerem o ouriço como uma barreira de proteção contra estes fungos além de confirmar os estudos anteriores do projeto Safenut que indicam a etapa de secagem sob ventilação e armazenamento das castanhas com casca durante meses no sistema extrativista como etapa crítica na contaminação por aflatoxinas. Portanto, no sistema de plantio, a coleta e o armazenamento após desinfecção com hipoclorito de sódio somente dos ouriços recém caídos das árvores, mesmo por um período de dois meses, permitem evitar a contaminação das castanhas por aflatoxinas

    Influence of postharvest water replacement on shelf life of parsley leaves.

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    Wilting is one of the major problems of parsley leaves in Brazilian retail stores. This study was conducted to determine the effect of postharvest replacement of water by submerging the parsley leaf bunches in water for 3, 6 or 9 hours at three stages: when total weight loss reached 5 and 10% and immediately after two hours of storage. Leaves were stored at 5 or 25ºC until visible wilting or yellowing was detected. Results demonstrated that water replacement resulted in gains in fresh mass, resulting in longer shelf life for leaves stored at 5 and 25ºC. In general, longer recharging resulted in greater water uptake by the leaves, but at a lower rate. By recharging the leaves with water, lower rates of mass loss were observed compared to untreated leaf bunches. Regardless the storage temperature, the relative water content of leaves decreased during shelf life, which in general was less accentuated for leaves submerged in water for 6 and 9 hours. Postharvest water replacement should be considered as an option to extend the shelf life of horticultural products that are susceptible to intense moisture loss

    Avaliação sensorial de farinha mista de castanha-do-brasil e banana verde.

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    O objetivo do trabalho foi avaliar sensorialmente mingaus fabricados a partir de 3 formulações de farinha mista de castanha-do-brasil e banana: A (50% castanha, 50% banana); B (33% castanha, 67% banana) e C (25% castanha, 75% banana). Foi realizado um teste de aceitação sensorial, sendo avaliados a aparência, aroma, textura, sabor, impressão global e intenção de compra. Em geral, todas as amostras tiveram boa aceitação sensorial, mas o atributo aparência recebeu piores notas que os demais. Para o atributo sabor, houve diferença significativa (p<0,05) entre os produtos A e C, mostrando que o aumento da proporção de farinha de castanha resultou em melhor sabor
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