3,252 research outputs found

    Toxicological Study Employing Repeated Doses of Garcinielliptone FC, a Polyisoprenylated-Benzophenone Isolated from Seed of Platonia Insignis Mart

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    The major constituent from the hexane extract of the seeds of P. insignis is GFC (garcinielliptone FC). Doses of 25, 50and 75 mg/kg of GFC were aseptically suspended in 0.05% Tween 80 dissolved in 0.9% saline (vehicle) and orally administered for30, 90 and 120 consecutive days to adult Swiss mice. In this work, the repeated oral administration, in animals of both sexes,demonstrates that this compound is not able to induce mortality and/or behavioral changes in adult mice. In addition, body weightgain, feed intake and disposal of excreta were not altered by the administration of this compound with repeated doses. Furthermore,no differences in weight and macroscopic structure of the brain, liver, kidney, lung, heart and spleen between groups of male andfemale adult mice were observed after treatment. During the periods of treatment, GFC produced no significant changes onhaematological and biochemical parameters in male and female mice treated with all doses used. The aim of this study was toinvestigate the toxicological potential of GFC through behavioral, hematological, biochemical and morphological parameters inanimals in order to ensure the safe use of Platonia insignis in folk medicine.Fil: Silva, Ana P.. Federal University of Piauí; BrasilFil: Filho, José Carlos C. L. S.. North Union of Parana; BrasilFil: da Costa Júnior, Joaquim S.. Federal Institute of Piauí; BrasilFil: Peláez, Walter José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Faillace, Martín Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Falcão Ferraz, Alexandre de B.. Lutheran University of Brazil; BrasilFil: David, Jorge M.. Institute Of Chemistry, Federal University Of Bahia; Brasil. Universidade Federal da Bahia; BrasilFil: Freitas, Rivelilson M.. Federal University of Bahia; Brasi

    Obtaining high purity silica from rice hulls

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    Many routes for extracting silica from rice hulls are based on direct calcining. These methods, though, often produce silica contaminated with inorganic impurities. This work presents the study of a strategy for obtaining silica from rice hulls with a purity level adequate for applications in electronics. The technique is based on two leaching steps, using respectively aqua regia and Piranha solutions, which extract the organic matrix and inorganic impurities. The material was characterized by Fourier-transform infrared spectroscopy (FTIR), powder x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM), particle size analysis by laser diffraction (LPSA) and thermal analysis

    Association of morphological and water factors with irrigated forage cactus yield

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    This study aimed to understand the relationship of morphological characteristics and actual evapotranspiration of forage cactus clones with their productive capacity under different water regimes. The data used in this study were collected between the years 2012 and 2013, in Serra Talhada, State of Pernambuco. The clones Sertânia IPA - IPA, Miúda - MIU and Orelha de Elefante Mexicana - OEM were submitted to three irrigation depths (2.5, 5.0 and 7.5 mm) and three irrigation intervals (7, 14 and 28 days). Cladode and plant morphology, accumulated actual evapotranspiration and yield were obtained at the moment of harvest. Pearson’s correlation matrix was elaborated and, in the sequence, multicollinearity, canonical and path analysis were applied. There was no correlation of yield with the soil water supply and actual evapotranspiration of the clones (p > 0.05). Forage cactus yield was more associated with peculiarities of the morphological characteristics of the clones than with the different soil water supplies or the crop actual evapotranspiration. However, regardless of the water regime and clone, the vigor of the basal cladodes was highly decisive for the expression of the forage cactus productive capacity.Objetivou-se, neste trabalho, compreender a relação de características morfológicas e da evapotranspiração real de clones de palma forrageira com sua capacidade produtiva em diferentes regimes hídricos. Os dados usados nesta pesquisa foram coletados entre os anos de 2012 e 2013, em Serra Talhada, PE. Os clones IPA Sertânia - IPA, Miúda - MIU e Orelha de Elefante Mexicana - OEM foram submetidos a três lâminas (2,5; 5,0; e 7,5 mm) e três intervalos de irrigação (7; 14 e 28 dias). Dados morfológicos dos cladódios e da planta, evapotranspiração real acumulada e desempenho produtivo foram obtidos na ocasião da colheita. A matriz de correlação de Pearson foi elaborada e, em seguida, foram aplicadas análises de multicolinearidade, canônica e de trilha. Não houve correlação da produtividade com o suprimento de água e evapotranspiração real dos clones (p > 0,05). A produtividade da palma esteve mais associada a peculiaridades das características morfológicas dos seus clones do que aos diferentes suprimentos de água no solo ou à evapotranspiração real da cultura. Mas, independente do regime hídrico e do clone, o vigor do cladódio basal foi bastante decisivo para a expressão da capacidade produtiva da palma forrageira irrigada

    Avaliação da Vulnerabilidade das Águas Subterrâneas no Município de Santa Cruz do Sul, RS/Brasil

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    Nesta pesquisa realizada no município de Santa Cruz do Sul, RS-Brasil, utilizou-se dados pré-existentes em banco de dados de empresas privadas, estatais, municipais e federais com o objetivo de espacializar as informações através da metodologia GOD e do aplicativo SURFER™ versão 6.0. Com essa metodologia GOD utilizada foi possível prever e avaliar a vulnerabilidade natural dos aqüíferos através dos parâmetros: grau de confinamento hidráulico (G); ocorrência do suprajacente (O) e distância do nível da água (D). Foi utilizada uma planilha eletrônica, MS Excel™, para dispor os parâmetros hidrodinâmicos e físico-químicos das águas subterrâneas. Ilustra-se a superfície potenciométrica indicativa do fluxo subterrâneo, as concentrações de flúor e o índice de vulnerabilidade. A faixa de variação do flúor foi de 0,0 até 3,6 mgL-1, e o índice de vulnerabilidade obtido, apresentou dos 25 poços simulados; 4 poços na classe desprezível, 7 poços na classe baixa, á poços na classe média e apenas 1 na classe alta. Discutem-se alguns aspectos relativos á legislação das águas subterrâneas e seu uso para abastecimento público

    Extração radicular de água e Kc em cultura de café

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    Basic information for a rational soil-water management of the coffee crop is still insufficient, particularly under irrigated conditions. Of great importance for the estimation of water requirements of coffee crops are their root distribuition and evapotranspiration crop coefficients. This study compares soil water extraction by roots of coffee plants of the variety Catuaí Vermelho (IAC-44), grown in Piracicaba, SP, Brazil, 3 to 5 years old, with direct measurements of root dry matter, showing a good agreement between both approaches, and confirming that most of the root system is distributed in the top soil layer (0-0.3 m) and that less than 10% of the root system reaches depths greater than 1.0 m. Calculated evapotranspiration crop coefficients are in agreement with those found in the literature, with an average of 1.1, independent of shoot dry matter, plant height and leaf area index.A informação básica para o manejo racional de água e solo na cultura de café ainda é insuficiente, sobretudo em condições de cultura irrigada. A distribuição radicular e os coeficientes de cultura para evapotranspiração são de grande importância para a estimativa da necessidade de água na cultura café. Este estudo compara a extração radicular de água de plantas de café, variedade Catuaí Vermelho (IAC-44), cultivado em Piracicaba, SP, Brasil, de 3 a 5 anos de idade, com medidas diretas de material seca de raiz, mostrando boa relação entre as metodologias e confirmando que a maioria do sistema radicular está distribuída na camada superficial de solo (0-0,3 m) e que menos de 10% do sistema radicular atingem profundidades maiores que 1,0 m. Os coeficientes de cultura medidos estão de acordo com aqueles encontrados na literatura, com média de 1,1, independentemente da matéria seca, altura de planta e índice de área foliar

    Análise Comparativa do Novo Paradigma Ecológico em dois Estados Brasileiros: A Gestão Ambiental além do Mercado e do Estado

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    Recent researches have shown that companies in Brazilians northeast deny assimilating a trend toincorporate the environmental management in their strategies. For long it is accepted that threewould be the three basic driving forces to corporate environmental management: themarketstructure; theStatewith its command=and= control mechanisms and policies, and thesociety(thecommunity). This article aims to identify the influence of the society, measuring their immersion ina new social paradigm, the New Environmental Paradigm – NEP, through the application of the“NEP=Scale Questionnaire”. The article intends to use students from five universities from twoBrazilian states, Ceará and Rio Grande do Sul, andcompares data results, to validate, or not, theinfluence of the third driving force towards a distinctive behavior in the companies at BraziliansNortheast. Even though a sample composed of university students can be thought as a limitingfactor, it adjusts the sample to a similar socioeconomic condition and level of access to information,consequently excluding those variables from analysis. The results validate the Scale and show adifferential between the both societies. It can bethe explanation from the companies’ behavi

    The weather conditions on rice yield in the State of São Paulo, Brazil

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    O objetivo deste trabalho foi medir o efeito das condições do tempo sobre a produtividade agrícola do arroz (Oryza sativa L.) em São Paulo. Utilizou-se a análise de regressão para estimar as relações entre a produtividade da cultura e as deficiências hídricas mensais. Os resultados sugerem grande sensibilidade do arroz à deficiência de água nos meses de janeiro, fevereiro e março. Alguns dos modelos ajustados fornecem previsões de rendimento melhores do que os levantamentos de campo, segundo os critérios de seleção adotados. The objective of this paper was to measure the effects of weather conditions on rice yield in the State of São Paulo, Brazil. Regression analysis was used to estimate the relation between crop yield and monthly hydric deficiencies. The results suggest great sensibility of rice to water deficiencies in January, February and March. Some of the adjusted models supply better yield forecasts than the field surveys, according to the adopted selection criteria

    Cutting Forces Assessment in CNC Machining Processes: A Critical Review

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    Machining processes remain an unavoidable technique in the production of high-precision parts. Tool behavior is of the utmost importance in machining productivity and costs. Tool performance can be assessed by the roughness left on the machined surfaces, as well as of the forces developed during the process. There are various techniques to determine these cutting forces, such as cutting force prediction or measurement, using dynamometers and other sensor systems. This technique has often been used by numerous researchers in this area. This paper aims to give a review of the different techniques and devices for measuring the forces developed for machining processes, allowing a quick perception of the advantages and limitations of each technique, through the literature research carried out, using recently published worksThe present work was done and funded under the scope of the project ON-SURF (ANI | P2020 | POCI-01-0247-FEDER-024521, co-funded by Portugal 2020 and FEDER, through COMPETE 2020-Operational Programme for Competitiveness and Internationalisation. F.J.G. Silva also thanks INEGI-Instituto de Ciência e Inovação em Engenharia Mecânica e Engenharia Industria, due to its support.info:eu-repo/semantics/publishedVersio
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