866 research outputs found

    Experimental evaluation of the employment of a laminated composite material with sisal fibres as reinforcement in timber beams.

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    Abstract Timber is the oldest construction materials in the world, have been widely used in structures in addition to having a high longevity, if treated properly (maintenance). If this does not occur, the wood deteriorates due to the action of insects, fungi and other aggressive agents. There are several materials and techniques used to reinforce the damaged parts. This paper presents an experimental study ofEucalyptus grandis and Pinus elliiottiitimber bea ms rein forced with sisal fibres laminated composite materials. The co mposite material and the wood were prepared for testing. In order to simulate the defect, some parts were cracked. The study was to determine the maximu m load (rupture) applied on the timberin the conditions: without defect, with defect and without composite and with defect and with composite, aiming to verify the efficiency of the laminate as reinforcement in the wooden beams. The experimental results indicate the possible use of the laminated composite as reinforcement, presenting considerable increase in the maximu m strength supported by the timber when compared to unreinforced cracked condition, being more efficient for the Pinus elliiottii species

    Esclerose Lateral Amiotrófica em uma índia brasileira Xikrin-Kayapó

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    Federal University of São Paulo Department of Neurology and NeurosurgeryFederal University of São Paulo Service of EndocrinologyUNIFESP, Department of Neurology and NeurosurgeryUNIFESP, Service of EndocrinologySciEL

    ENVIRONMENTAL PERCEPTION IN PERMANENT PRESERVATION AREA (PPA) RESTORED IN THE WESTERN AMAZON, BRAZIL: A CASE REPORT

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    Restorations of anthropogenically degraded ecosystems present a relative demand for information that influences the success of the project. Environmental analysis, with the interface of ethnobotany and the management of the rural producer with the plants that make up these areas can make the experiments successful. We aimed verify the environmental perception and ethnobotany in the area of permanent preservation (PPA) restored in the Western Amazon. Data were collected through semi-structured and open interviews, direct observation, life history and walks-in-the-woods and participant observations. The restoration takes place nine years ago and was implemented to comply with environmental legislation. Currently the revegetation area serves as an ecological corridor, animal shelter and protection of local water resources, and has been evaluated positively given the environmental importance for the region. The most represented botanical families were Fabaceae and Meliaceae their products are considered sources of food and medicines. The revegetation in the area provides shading, which favors the volume of the water course and also influencing the local microclimate

    TRADITIONAL KNOWLEDGE AND RESTORATION OF PERMANENT PRESERVATION AREA IN RONDONIA. BRAZIL

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    Abstract: Restorations of anthropogenically degraded ecosystems present a relative demand for information that influences the success of the project. Environmental analysis, with the interface of ethnobotany and the management of the rural producer with the plants that make up these areas can make the experiments successful. We aimed verify the environmental perception and ethnobotany in the area of permanent preservation (PPA) restored in the Western Amazon. Data were collected through semi-structured and open interviews, direct observation, life history and walks-in-the-woods and participant observations. The restoration takes place nine years ago and was implemented to comply with environmental legislation. Currently the revegetation area serves as an ecological corridor, animal shelter and protection of local water resources, and has been evaluated positively given the environmental importance for the region. The most represented botanical families were Fabaceae and Meliaceae their products are considered sources of food and medicines. The revegetation in the area provides shading, which favors the volume of the water course and also influencing the local microclimate. Keywords: Restoration, Traditional knowledge, Ethnobotan

    Response of African oil palm to nitrogen addition and its influence on the diazotrophic bacteria population

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    O dendê (Elaeis guineensis, Jaquim) pode produzir até sete toneladas de óleo por hectare por ano. O óleo vegetal é muito versátil e pode ser usado desde a indústria alimentícia até a produção de biocombustíveis. A planta é capaz de se associar com bactérias diazotróficas que colonizam raízes e caules. O objetivo deste trabalho foi avaliar a resposta à adubação nitrogenada de 17 genótipos de dendê no primeiro ano de cultivo e avaliar a influência da adição do N mineral sobre a população de bactérias diazotróficas, naturalmente presentes nas plântulas de dendezeiro. Foram utilizados potes de plástico completados com 50% de areia quartzoza e 50% de horizonte B de um Argissolo Vermelho-Amarelo, série Itaguaí, não esterilizado e extremamente pobre em nitrogênio. A uréia foi aplicada na dosagem de 33,68 kg ha-1 de N. Na presença do N, todos os genótipos melhoram os parâmetros biométricos, e houve aumento tanto do N total quanto do N acumulado. As populações de bactérias diazotróficas não foram influenciadas pela adição desse elemento. Dois genótipos foram selecionados, na presença e ausência de N, respectivamente, C-2001 e La Mé.African oil palm (Elaeis guineensis, Jaquim) can produce up to 7 tons of oil per hectare per year. The vegetable oil is greatly versatile in its use, since food industry up to the production of fuels favorable to environmental protection. The plant has the potential to be associative with diazotrophic bacteria which colonize the roots and stem. The objective of this work was to evaluate 17 genotypes of E. guineensis in response to nitrogen addition and to verify the influence of this nitrogen on the diazotrophic population in an experiment using plastic pots filled with 50% quartz sand and 50% of non sterilized Horizon B; Red-Yellow Podzolic Soil series Itaguaí, extremely poor in nitrogen. Urea was used at a dose of 33.68 kg ha-1 de N. In the presence of the nitrogen, all genotypes improved biometric parameters, increased total nitrogen and its accumulation. Its addiction did not affect the diazotrophic population. Two genotypes were selected in the presence and absence of nitrogen: C-2001 and La Mé, respectively

    Mycorrhizal fungi and phosphate fertilization in the production of Euterpe edulis seedlings

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    The present study evaluated the effect of arbuscular mycorrhizal fungi (AMF) inoculation on growth and nutrition of Euterpe edulis seedlings, supplemented or not with phosphate fertilization. The experiment was conducted in a greenhouse. The randomized block design, consisted of a 3x2 factorial arrangement and 4 replicates, with two phosphorus doses (0 and 50 mg dm-3 of soil), two microbiological treatments (Rhizophagus clarus;  laroideoglomus etunicatum; R. clarus + C. etunicatum) and control (without fungus). Sowing and inoculation occurred concurrently in 2 kg plastic bags. Height, collar diameter, leaf area, dry shoot mass, macronutrient content and mycorrhizal colonization percentage were determined after 226 days. Regarding mycorrhizal colonization percentage, R. clarus resulted significantly beneficial for the production of E. edulis seedlings. In the absence of phosphate fertilization, R. clarus and mixed inoculum increased all biometric variables and macronutrient contents in seedlings. Therefore, it is concluded that AMF inoculations provide beneficial effects for growth and nutrition of E. edulis seedlings, resulting in more vigorous plants at a low-cost strategy. Highlights: Rhizophagus clarus resulted significantly beneficial for the production of E. edulis seedlings and in the absence of phosphate fertilization, and mixed inoculum ( clarus + Claroideoglomus etunicatum) increased all biometric variables and macronutrient contents in seedlings. The AMF inoculations provide beneficial effects for growth and nutrition of E. edulis seedlings, resulting in more vigorous plants at a low-cost strategy. The AMF, a biological agent of mutualistic associations with plants, constitutes an innovative approach to sustainable agriculture, contributing to increase plant survival rate, a key-factor for the successful reintroduction and conservation of E. edulis, as well as for its commercial exploitation.The present study evaluated the effect of arbuscular mycorrhizal fungi (AMF) inoculation on growth and nutrition of Euterpe edulis seedlings, supplemented or not with phosphate fertilization. The experiment was conducted in a greenhouse. The randomized block design, consisted of a 3x2 factorial arrangement and 4 replicates, with two phosphorus doses (0 and 50 mg dm-3 of soil), two microbiological treatments (Rhizophagus clarus;  laroideoglomus etunicatum; R. clarus + C. etunicatum) and control (without fungus). Sowing and inoculation occurred concurrently in 2 kg plastic bags. Height, collar diameter, leaf area, dry shoot mass, macronutrient content and mycorrhizal colonization percentage were determined after 226 days. Regarding mycorrhizal colonization percentage, R. clarus resulted significantly beneficial for the production of E. edulis seedlings. In the absence of phosphate fertilization, R. clarus and mixed inoculum increased all biometric variables and macronutrient contents in seedlings. Therefore, it is concluded that AMF inoculations provide beneficial effects for growth and nutrition of E. edulis seedlings, resulting in more vigorous plants at a low-cost strategy. Highlights: Rhizophagus clarus resulted significantly beneficial for the production of E. edulis seedlings and in the absence of phosphate fertilization, and mixed inoculum ( clarus + Claroideoglomus etunicatum) increased all biometric variables and macronutrient contents in seedlings. The AMF inoculations provide beneficial effects for growth and nutrition of E. edulis seedlings, resulting in more vigorous plants at a low-cost strategy. The AMF, a biological agent of mutualistic associations with plants, constitutes an innovative approach to sustainable agriculture, contributing to increase plant survival rate, a key-factor for the successful reintroduction and conservation of E. edulis, as well as for its commercial exploitation.

    Trends of COVID-19 pediatric admissions number during the first 24 weeks of COVID-19 vaccination in Rio de Janeiro, Brazil / Tendências do número de admissões pediátricas da COVID-19 durante as primeiras 24 semanas de vacinação da COVID-19 no Rio de Janeiro, Brasil

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    Objective: To describe trends of COVID-19 pediatric admissions number during the first 24 weeks of COVID-19 vaccination.   Design: A retrospective study was conducted in children (0-18 years), admitted in two pediatric hospitals of Rio de Janeiro city, between January 17 and July 3, 2021 with confirmed COVID-19 by reverse transcription polymerase chain reaction or serological tests. Trends of COVID-19 pediatric admissions number during the first 24 weeks of COVID-19 vaccination in Rio de Janeiro, Brazil and the pre-vaccine period were measured by linear regression. Participants: Children admitted in pediatric hospitals in Rio de Janeiro, city, Brazil Results: The number of total admitted patients (with all diseases) were 5340 during the pre-vaccine period, being 94 (1.8%) of them with confirmed COVID-19, and 4182 children admitted during the vaccine period, with 86 confirmed COVID-19 patients (2.1 %) (p=0.29). Media of cases admitted per/week were 2.02 in pre-vaccine period and 3.6 during the first 24 weeks of COVID vaccination (p=0.009). One death was reported in the pre-vaccine period and four in the vaccine period (p=0.14). Trends of increase in the number of admitted cases were verified both in the pre-vaccine period as in the vaccine period, being more expressive in the last one. Conclusion: There was trend of increase in number of children admitted with confirmed COVID-19 during the first 24 weeks of COVID-vaccination in Rio de Janeiro, city. Considering that few people were fully vaccinated, reducing of number of admitted children with confirmed COVID-19 was not verified

    Characterization of decavanadate and decaniobate solutions by Raman spectroscopy

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    The decaniobate ion, (Nb10 = [Nb10O28]6−) being isoelectronic and isostructural with the decavanadate ion (V10 = [V10O28]6−), but chemically and electrochemically more inert, has been useful in advancing the understanding of V10 toxicology and pharmacological activities. In the present study, the solution chemistry of Nb10 and V10 between pH 4 and 12 is studied by Raman spectroscopy. The Raman spectra of V10 show that this vanadate species dominates up to pH 6.45 whereas it remains detectable until pH 8.59, which is an important range for biochemistry. Similarly, Nb10 is present between pH 5.49 and 9.90 and this species remains detectable in solution up to pH 10.80. V10 dissociates at most pH values into smaller tetrahedral vanadate oligomers such as V1 and V2, whereas Nb10 dissociates into Nb6 under mildly (10 > pH > 7.6) or highly alkaline conditions. Solutions of V10 and Nb10 are both kinetically stable under basic pH conditions for at least two weeks and at moderate temperature. The Raman method provides a means of establishing speciation in the difficult niobate system and these findings have important consequences for toxicology activities and pharmacological applications of vanadate and niobate polyoxometalates
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