171 research outputs found

    Thermal analysis of cement panels with lignocellulosic materials for building

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    The use of lignocellulosic material residue in cement composites can be considered as a good option because they allow good thermal behaviour. This paper aimed to compare three kinds of cement panels reinforced with different lignocellulosic materials (Coffee husk, Coconut shell, and Banana pseudostem) based on their thermal properties. To produce each panel, the methodology suggested by Souza (1994) was used. Six replicates of each lignocellulosic panel with dimensions of 7.0×7.5 were evaluated. The thermal analysis was performed in a chamber composed of MDP (medium density particleboard). The chamber contained the heat source (incandescent lamp) connected to a thermostat that maintained the temperature at 48.0 °C. The porosity and thickness of the panels and the thermal behaviour of each sample panel (thermal conductivity, resistivity, resistance, and transmittance) and the difference in temperature of both sides of the panel were evaluated. The temperature difference to stabilization was obtained after a sampling time of 200 minutes, with 1,000 readings of 12 s each. Although all the panels were submitted under the same temperature, the inner and external superficial temperatures of the coffee husk panels reached smaller values. Besides, coconut and banana pseudostem panels presented the best results of thermal transmittance and thermal resistance. Thus, coconut shell panels present the best thermal performance, which means that this panel might be an attractive alternative building material, in terms of heat insulation for indoor applications

    Qualidade Sanitária E Germinação De Sementes De Butia Capitata Tratadas Com Bactericida E Fungicida

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Propagation of “coquinho-azedo” (Butia capitata) is limited due to dormancy and high incidence of fungi in its seeds. The aim of this study was to evaluate the effect of treating “coquinho-azedo” seeds with different concentrations of bactericide and/or fungicide on the incidence of fungi and on the germination of seeds. Thus, B. capitata seeds were immersed in four doses of the bactericide kasugamycin (0, 1.5, 3.0 and 4.5 mL/L) and/or in four concentrations of the fungicide carbendazim+ thiram (0, 2.92, 5.84 e 8.75 mL/ Kg), totaling 16 treatments. After the treatments, the operculum was removed from the seeds, which were placed on trays containing autoclaved sand, covered with transparent plastic film and kept in the nursery. In the germination test, treatments were distributed in randomized block design, factorial arrangement of 4×4 (bactericidal doses × fungicide doses), with four replicates of 50 seeds per plot. For the test of seed health quality, the Blotter test was employed in completely randomized design, using 20 replicates and 10 seeds. Health quality and germination were evaluated at 15 and 40 days after the treatment of seeds, respectively. There was no interaction between the bactericide and the fungicide on germination and control of fungi associated with seeds. However, there was an effect of fungicide concentrations on the evaluated parameters. We observed a negative correlation between the concentrations of the fungicide carbendazim + thiram and fungal incidence, and a positive correlation between the fungicide concentrations and seed germination. Therefore, fungicide treatment reduces the fungal incidence and provides better germination of B. capitata seeds. © 2016, Universidade Estadual Paulista (UNESP). All rights reserved.424303307CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Central Santa Catarina coastal dunefields chronology and their relation to relative sea level and climatic changes

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    During the past decades, there have been contrarian explanations for the formation and stabilization of coastal dunefields: while many authors believe the dunes formation would be enhanced by falling sea level, others argue that a rising or stable sea level context would be favorable. For Brazilian coastal dunefields, the second hypothesis seems to be more consistent with the luminescence ages found so far; however, most of these data were obtained without using the SAR protocol. Another point of concern is the role of climate change in the aeolian system, which is still not very clear. The aim of this paper is to try to clarify these two questions. To this end, five coastal dunefields were selected in central Santa Catarina coast. The remote sensing and dating results allowed the discrimination and mapping of at least four aeolian generations. Their age distribution in relation to the global curve of relative sea level variation during the Late Pleistocene allows us to suggest that the formation of Aeolian dunefields in the coastal context is supported by stable relative sea level. However, relative sea level is not the only determinant for the formation and preservation of the aeolian coastal dunes. Evidences of climatic control indicate that the initiation of dunefields would be favored by periods of less humidity while their stabilization would occur preferably during the periods of rain intensification, connected to monsoon activity

    Combination of searches for Higgs boson pairs in pp collisions at \sqrts = 13 TeV with the ATLAS detector

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    This letter presents a combination of searches for Higgs boson pair production using up to 36.1 fb(-1) of proton-proton collision data at a centre-of-mass energy root s = 13 TeV recorded with the ATLAS detector at the LHC. The combination is performed using six analyses searching for Higgs boson pairs decaying into the b (b) over barb (b) over bar, b (b) over barW(+)W(-), b (b) over bar tau(+)tau(-), W+W-W+W-, b (b) over bar gamma gamma and W+W-gamma gamma final states. Results are presented for non-resonant and resonant Higgs boson pair production modes. No statistically significant excess in data above the Standard Model predictions is found. The combined observed (expected) limit at 95% confidence level on the non-resonant Higgs boson pair production cross-section is 6.9 (10) times the predicted Standard Model cross-section. Limits are also set on the ratio (kappa(lambda)) of the Higgs boson self-coupling to its Standard Model value. This ratio is constrained at 95% confidence level in observation (expectation) to -5.0 &lt; kappa(lambda) &lt; 12.0 (-5.8 &lt; kappa(lambda) &lt; 12.0). In addition, limits are set on the production of narrow scalar resonances and spin-2 Kaluza-Klein Randall-Sundrum gravitons. Exclusion regions are also provided in the parameter space of the habemus Minimal Supersymmetric Standard Model and the Electroweak Singlet Model. For complete list of authors see http://dx.doi.org/10.1016/j.physletb.2019.135103</p
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