782 resultados para Plant material. eng


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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O método para rápido aumento da produtividade fabril, aplicável principalmente à indústria brasileira de manufatura (17% do PIB), fundamenta-se exclusivamente na redução ou eliminação do tempo inativo do homem, da máquina e do material, que é a grande causa da ineficiência. O método exige a utilização de apenas cinco das mais simples, elementares e conhecidas técnicas e é aplicável às vinte situações mais freqüentes (objetos de estudo) na indústria de manufatura. Nossa experiência atesta que o método pode proporcionar à produtividade fabril um aumento superior a 30%, em poucos meses e de forma perene. Sua aplicação e a implantação das medidas dele decorrentes são feitas com extrema facilidade e, por isto, os resultados surgem muito rapidamente. Atinge portanto seu objetivo: proporcionar aumento da produtividade fabril em curto espaço de tempo. Este artigo (terceiro e último da série) detalhará doze objetos de estudo (situações): 1. redução dos tempos inativos causados por troca de turno, por refeição e por troca de produtos; 2. redução dos tempos improdutivos acarretados por causas mais importantes, por espera pelo serviço de manutenção, por espera pelo serviço de preparação, por espera pelo operador e por causas não apontáveis pelos procedimentos usuais; 3. redução das atividades improdutivas e das produtivas executadas num ritmo improdutivo; e 4. redução do tempo de espera do material em processamento pela redução do tamanho do lote de fabricação e pelo aumento da velocidade de manufatura.

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This work describes the use of a large-aperture PVDF receiver in the measurement of liquid density and composite material elastic constants. The density measurement of several liquids is obtained with accuracy of 0.2% using a conventional NDE emitter transducer and a 70-mm-diameter, 52-mu m P(VDF-TrFE) membrane with gold electrodes. The determination of the elastic constants is based on the phase velocity measurement. Diffraction can lead to errors around 1% in velocity measurement when using alternatively the conventional pair of ultrasonic transducers (1-MHz frequency and 19-mm-diameter) operating in through-transmission mode, separated by a distance of 100 mm. This effect is negligible when using a pair of 10-MHz, 19-mm-diameter transducers. Nevertheless, the dispersion at 10 MHz can result in errors of about 0.5%, when measuring the velocity in composite materials. The use of an 80-mm diameter, 52-mu m-thick PVDF membrane receiver practically eliminates the diffraction effects in phase velocity measurement. The elastic constants of a carbon fiber reinforced polymer were determined and compared with the values obtained by a tensile test. (C) 2009 Elsevier B. V. All rights reserved.

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Vegetable-based polyurethane (PU) was prepared in the thin film form by spin coating. This polymer is synthesised from castor oil, which can be extracted from the seeds of a native plant in Brazil called mamona. This polymer is biocompatible and is being used as material for artificial bone. The PU was characterised by dielectric spectroscopy in a wide range of frequency (10(-5) Hz to 10(5) Hz) and by thermally stimulated discharge current (TSDC) measurements. The glass transition temperature (T-g=39degreesC) was determined and using the initial rise method the activation energy was found to be 1.58 eV. (C) 2003 Kluwer Academic Publishers.

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During the building of a hydroelectrical power plant at Ilha Solteira in the Parana River (Brazil), materials of a highly weathered soil Oxisol were extracted from a depth between 5 and 8 m for engineering works. This resulted in an abandoned depression area. The topsoil was not salvaged and the open pit was not backfilled, and as result vegetation hardly or not at all recovered. on the residual saprolite materials, an experimental field was established to assess different soil rehabilitation treatments. Field experiments were initiated in 1992. After soil tillage, two different crops and three different liming strategies were compared, giving six combinations. In addition, two uncropped control treatments, tilled and no-tilled, were established so that a total of eight treatments were assessed. The experimental design consisted of four randomized experimental blocks, which included a total of 32 plots with a plot area of 100 m(2). This experiment was used to study the effectiveness of the soil-reclamation treatments after a 9-year period. Soil samples were taken at three different depths (0-10, 10-20, and 20-40 cm), and they were analyzed routinely for pH, organic-matter content, and cation exchange capacity (CEC). Revegetation of the abandoned saprolite material increased soil organic-matter content and cation exchange capacity (CEC), and to some extent small differences between treatments were evidenced. Exchangeable calcium (Ca) and magnesium (Mg) recovered faster than organic-matter content. A significant linear relationship was found between organic-matter content and CEC, suggesting continued addition of organic material will further approach the value of these parameters to those levels corresponding to natural soils under "Cerrado" vegetation.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Recently a textile azo dye processing plant effluent was identified as one of the sources of mutagenic activity detected in the Cristais River, a drinking water source in Brazil [G.A. Umbuzeiro, D.A. Roubicek, C.M. Rech, M.I.Z. Sato, L.D. Claxton, Investigating the sources of the mutagenic activity found in a river using the Salmonella assay and different water extraction procedures, Chemosphere 54 (2004) 1589-1597]. Besides presenting high mutagenic activity in the Salmonella/microsome assay, the mutagenic nitro-aminoazobenzenes dyes CI Disperse Blue 373, Cl Disperse Violet 93, and CI Disperse Orange 37 [G.A. Umbuzeiro, H.S. Freeman, S.H. Warren, D.P Oliveira, Y. Terao, T. Watanabe, L.D. Claxton, the contribution of azo dyes in the mutagenic activity of the Cristais river, Chemosphere 60 (2005) 55-64] as well as benzidine, a known carcinogenic compound [T.M. Mazzo, A.A. Saczk, G.A. Umbuzeiro, M.V.B. Zanoni, Analysis of aromatic amines in surface waters receiving wastewater from textile industry by liquid chromatographic with eletrochemical detection, Anal. Lett., in press] were found in this effluent. After similar to 6 km from the discharge of this effluent, a drinking water treatment plant treats and distributes the water to a population of approximate 60,000. As shown previously, the mutagens in the DWTP intake water are not completely removed by the treatment. The water used for human consumption presented mutagenic activity related to nitro-aromatics and aromatic amines compounds probably derived from the cited textile processing plant effluent discharge [G.A. Umbuzeiro, D.A. Roubicek, C.M. Rech, M.I.Z.. Sato, L.D. Claxton, Investigating the sources of the mutagenic activity found in a river using the Salmonella assay and different water extraction procedures, Chemosphere 54 (2004) 1589-1597; G.A. Umbuzeiro, H.S. Freeman, S.H. Warren, D.P. Oliveira, Y. Terao, T. Watanabe, L.D. Claxton, the contribution of azo dyes in the multagenic activity of the Cristais river, Chemosphere 60 (2005) 55-64]. Therefore, it is important to evaluate the possible risks involved in the human consumption of this contaminated water. With that objective, one sample of the cited industrial effluent was tested for carcinogenicity in the aberrant crypt foci medium-term assay in colon of Wistar rats. The rats received the effluent in natura through drinking water at concentrations of 0.1%, 1%, and 10%. The effluent mutagenicity was also confirmed in the Salmonella/microsome assay with the strains TA98 and YG1041. There was an increased number of preneoplastic lesions in the colon of rats exposed to concentrations of 1% and 10% of the effluent, and a positive response for both Salmonella strains tested. These results indicate that the discharge of the effluent should be avoided in waters used for human consumption and show the sensitivity of the ACF crypt foci assay as an important tool to evaluate the carcinogenic potential of environmental complex mixtures. (c) 2006 Elsevier B.V. All rights reserved.

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The expansion of global poultry production has increased the need to reduce or control the agents responsible for economic losses, including Salmonella spp. These bacteria are also of public health concern due to their potential to cause food poisoning, and, more recently, due to the antimicrobial resistance presented by these bacteria. Molecular biology is an important tool currently used in the diagnosis and research studies of main poultry diseases. The present studied analyzed 100 samples of Salmonella Enteritidis (SE) isolated from avian material aiming at detecting the class 1 integron gene, Integroninvolved in antimicrobial resistance, by means of polymerase chain reaction (PCR), and comparing it with plate inhibition test. Subsequently, SE samples were evaluated for their capacity to horizontally transfer this gene. There was no direct relationship between the presence of the class 1 integron gene and SE resistance to the 14 antimicrobials tested, as 80% of the studied samples were resistant to up to three antimicrobials, and did not present the aforementioned gene. However, horizontal transfer of this gene was accomplished in vitro (from Escherichia coli to Salmonella Enteritidis), demonstrating that capacity class 1 integron gene can be disseminated among enterobacteria.

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A mandioca, apesar de ser nativa do Brasil, ainda é sub-utilizada principalmente quando a questão é o aproveitamento da sua parte aérea. Com o objetivo de estudar o potencial da mandioca para alimentação animal, o presente trabalho avaliou as características da parte aérea da planta quando submetida os processos de ensilagem e fenação. Os tratamentos consistiram de: parte aérea ensilada sem emurchecimento (PAS); parte aérea ensilada após 24 horas de emurchecimento (PAE) e parte aérea fenada (PAF). As análises químicas foram realizadas a fim de avaliar os parâmetros que determinam o valor nutritivo da silagem e do feno. O emurchecimento elevou o teor de matéria seca de 25% no material in natura para 27.7%, sem alterar o teor de carboidratos solúveis (33.3 e 35.5% de MS na PAS e PAE respectivamente), bem como o poder tampão (204 mmol kg-1 MS na PAS e 195 mmol kg-1 MS na PAE). Nem o pH (3.57 na silagem in natura e 3.60 na PAE) nem os teores de NIDA (11.32% do nitrogênio total na MS na PAS e 9.99% do nitrogênio total na MS na PAE) diferiram entre as silagens, mas o NIDA foi maior na forragem fenada (15.39%). Contudo, o emurchecimento provocou aumento no nitrogênio amoniacal (de 6.5% do nitrogênio total na MS da PAS para 13.0 do nitrogênio total na MS da PAE). Os teores de ácidos graxos voláteis não sofreram alterações com o emurchecimento. O processo de ensilagem reduziu os teores de ácido cianídrico livre (HCN), sem, contudo, alterar a cianidrina.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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A double antibody sandwich ELISA (DAS-ELISA) was developed and employed for simultaneous direct detection of infectious bursal disease virus (IBDV) from bursal samples and to measure the humoral response, using the same basic immunoreagents, the purified and non-purified antigen, capture antibody and chicken hyperimmune sera were prepared, and standardized for this purpose, the DAS-ELISA was applied to both 80 bursal suspensions and 224 corresponding serum samples from vaccinated and non-vaccinated commercial hocks, Bursae samples were collected at 2 weeks of age, and submitted to histological examination, virus isolation in specific pathogen-free chickens embryos, and the DAS-ELISA technique, Serum titres obtained in indirect ELISA and serum neutralization test were compared with those in DAS-ELISA, the agreement was 80% between DAS-ELISA, and the conventional techniques, with high sensitivity (87%) and specificity (90%).