760 resultados para acrylonitrile butadiene(NBR) rubbers
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The present dissertação had as objective to study the ambient management in the Farms Saint Rita, Tahim Agropesca and Agropesca Rigomoleiro, in the Great River of the North. For this we use as theoretical tool some fundantes concepts of geographic science, the space, and as concepts auxiliary of ambient management, of estuaries as the half natural one and of manguezais as ecosystem. The study if it gave taking in consideration a model of flow of activities of a typical farm following the way of the residues produced since the beginning until its final destination, in a suitable script of SCHERER (1999). The considered flow established a sequence activities where it is identified the material of entrance, the process of management, the residues of exit and the destination of the residues to the long one of the phase of culture of the shrimp. From it was there had been elaborated a series of managemental pictures with the data raised in the three farms, of different transports and concludes that the ambient management of these farms does not follow the formal standards of a system of typical ambient management. Collating with the system of considered by norm ISO14000 the study it disclosed that all the companies are in a situation of not conformity and that the impacts on the environment continue being many significant ones. However, it is possible to implant norm ISO14000 because some procedures implanted for the farms are correct of the point of view of the ambient management
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Avaliaram-se os efeitos de diferentes porcentagens (0, 10, 20 e 30%) de inclusão da torta de macaúba (TM) no comportamento ingestivo de 24 cordeiros Santa Inês, com média de cinco meses de idade e peso vivo de 23,9kg, distribuídos em delineamento em blocos ao acaso, com quatro tratamentos e seis repetições, durante 60 dias de confinamento. Foram avaliados os tempos médios despendidos com alimentação, ruminação (TR), ócio (TO), tempo de mastigação total (TMT), eficiência de alimentação (EA MS e EA FDN) e eficiência de ruminação, além do número de bolos ruminados (NBR) e número diário de mastigações merícicas (MMnd). A adição de TM à dieta aumentou linearmente o TR, TMT, NBR, MMnd e EA FDN e reduziu de forma linear o TO, em consequência do maior teor de fibra em detergente neutro das dietas com o coproduto. Mesmo com o aumento no TMT, não foi verificada diferença no consumo e na eficiência de ruminação e alimentação da matéria seca, possivelmente em razão da baixa efetividade de fibra da TM, demonstrando o potencial de utilização desse coproduto na dieta de ovinos em crescimento.
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O principal objetivo deste trabalho é verificar, por meio de uma pesquisa tipo survey, os benefícios e as dificuldades da adoção de Sistemas de Gestão Ambiental ISO 14001 em empresas industriais do Estado de São Paulo. Para tal, um questionário foi enviado para 194 empresas constantes da base de dados do INMETRO (Instituto Nacional de Metrologia, Normalização e Qualidade Industrial) e respondido por 69 delas, representando uma taxa de retorno de 35,36%. Duas hipóteses foram estabelecidas para realização do estudo: uma enunciando os potenciais benefícios e outra as dificuldades da gestão ambiental com base na norma NBR ISO 14001. Estas hipóteses foram parcialmente comprovadas. O artigo está estruturado da seguinte forma: introdução, sistema de gestão ambiental, norma NBR ISO 14001, método de pesquisa, apresentação e análise dos resultados, conclusão e referências bibliográficas.
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Este trabalho teve como objetivo o estudo de fatores de risco associados à mastite bovina causada por Prototheca zopfii. Foram analisadas 13 propriedades leiteiras dos Estados do Paraná e de São Paulo, segundo os seguintes critérios de seleção: confirmação prévia de casos de mastite por Prototheca spp., triagem pela pesquisa de Prototheca spp. em tanques de expansão e latões e rebanhos com contagem de células somáticas acima de 5x105cel mL-1. As amostras coletadas consistiram de: leite, água, solo, fezes e swab de teteiras. Prototheca spp. foi isolada de amostras de leite dos quartos mamários com mastite clínica ou subclínica em uma propriedade e de amostras de leite e do ambiente em quatro propriedades, nas quais foi isolada em amostras de: água de bebedouro, abastecimento, esgoto, empoçada no piso de estábulo e sala de ordenha, solo de piquete e pasto, teteiras, fezes de bezerros e suínos. do total de 383 vacas examinadas, Prototheca spp. foi isolada em 20 (5,2%) vacas, sendo caracterizada como P. zopfii em 18. Os fatores de risco associados à mastite causada por P. zopfii foram: criação das vacas a pasto, alimentação dos animais com pasto e silagem, realização de ordenha mecânica em estábulo, permanência das vacas após ordenha em piquete sem alimento, criação de suínos próxima às instalações dos bovinos, existência de cães, gatos e roedores, falta de higienização dos tetos com água, pré-imersão dos tetos em aplicador com retorno e sem a troca do anti-séptico, alimentação dos bezerros com leite de vacas com mastite clínica e serem as vacas da raça holandesa.
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In this research it was studied a system composed by the anaerobic filter combined with a sand filter for the wastewater treatment. For this, three anaerobic filters were operated with hydraulic detention time of nine hours which had the effluent disposed over four sand filters in different frequencies of application. on the first sand filter, 50 L.m(-2) were applied once a day. on the second, the third and the fourth filters, the same load was disposed in twice, three and four times a day, distributed between 9 a. m. and 4 p. m. The system presented a final effluent suitable for the COD and BOD legislation maximum limit to be discharged into water body (Decreto Paulista no 8,468/1976), showing the viability of dispose a higher quantity of effluent then the one suggested by NBR 13969/1997, which guides the constructive aspects for this kind of treatment.
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The distribution of short-circuit current is investigated by means of two methods, one direct and the other analytic; both methods consider uniform probability distribution of line faults. In the direct method, the procedure consists of calculating fault currents at equidistant points along the line, starting from one of the end points and considering the other end open. The magnitude of the current is classified according to Brazilian standards (regulation NBR-7118). The analytic method assumes that the distribution of short-circuit currents through the busbar and the distribution of the line length connected to it are known, as well as the independence of values. The method is designed to determine the probability that fault currents through a line will surpass the pre-established magnitude, thus generating frequency distribution curves of short-circuit currents along the lines.
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The compaction rate, the relation between the density of the wood panel and the density of the wood used for producing the particles, is an indicator of the product's densification. Among the various types of wood panels, particleboards are widely employed in the lumber industry, mainly for the furniture production. This paper presents a study of the relation between the compaction rate and the properties of tensile strength perpendicular to surface, Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) obtained from a static bending test, thickness swelling and water absorption (2 and 24 hours). These properties were calculated according to the Brazilian ABNT, NBR 14810 standard. Particleboards were produced using the species Pinus elliotti and adhesive ureaformaldehyde. The relation was established by a multiple linear regression, and the most appropriate statistical models were determined. The estimated models indicate statistically significant effects of water absorption in 2 hours and MOR in the particleboards' compaction rate.
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Latex is the main product extracted from rubber trees (Hevea brasiliensis). In Brazil, at the end of the production cycle of latex, the wood of rubber tree is traditionally used for energy purposes, but several international studies have reported consolidated practices of adding value to it. The objective of this paper was to evaluate the quality of wood and classify it structurally based on its mechanical properties. Six 20-year-old trees of the clone GT 1 of rubber tree proceeding from Itajobi, State of Sao Paulo, Brazil were sampled. Reduced dimensions specimens in the radial direction of the wood were produced to evaluate the quality by compression parallel to the grain, static bending and Janka hardness tests. Two specimens, one from the lower log (since the ground up to breast height) and one from the higher log (from breast height up to 2.50 m) were produced for structural classification of the wood based on the characteristic strength in compression parallel to the grain (NBR 7190 norm, 1997). The wood was classified as C40 (fc0k ≥ 40 MPa) class. Results revealed that the strength was not statistically different in the radial direction (except for the Janka hardness), though tending to increase from pith to bark.
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In the majority of cases of bone fracture requiring surgery, orthopedic implants (screw-plate and screw) are used for osteosynthesis and the infections associated with such implants are due to the growth of microorganisms in biofilms. The objective of this study was to identify microorganisms recovered from osteosynthesis implants used to fix bone fractures, to assess the viability of the cells and the ability of staphylococci to adhere to a substrate and to determine their sensitivity/resistance to antimicrobials. After surgical removal, the metal parts of austenitic stainless steel (ASTM F138/F139 or ISO NBR 5832-1/9) were transported to the Laboratory of Clinical Microbiology, washed in buffer and subjected to ultrasonic bath at 40±2 kHz for 5 minutes. The sonicated fluid was used to seed solid culture media and cell viability was assessed under the microscope by with the aid of a fluorescent marker. The production of extracellular polysaccharide by Staphylococcus spp. was investigated by means of adhesion to a polystyrene plate. The profile of susceptibility to antimicrobials was determined by the disk diffusion assay. The most frequently isolated bacteria included coagulase-negative Staphylococcus resistant to erythromycin, clindamycin and oxacillin. Less frequent were Pseudomonas aeruginosa resistant to trimethoprim/sulfamethoxazole and ampicillin, Acinetobacter baumannii resistant to ceftazidime, Enterobacter cloacae resistant to cephalothin, cefoxitin, cefazolin, levofloxacin and ciprofloxacin, Bacillus spp. and Candida tropicalis. The observation of slides by fluorescence microscope showed clusters of living cells embedded in a transparent matrix. The test for adherence of coagulase-negative Staphylococcus to a polystyrene plate showed that these microorganisms produce extracellular polysaccharide. In conclusion, the metal parts were colonized by bacteria related to orthopedic implant infection, which were resistant to multiple antibiotics.
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This research aimed to test particleboard with leucena (Leucaena leucocephala) wood particles and polyurethane resin castor oil based. The response variables are: modulus of rupture (MOR), internal adhesion (AI), apparent density (dap) and wood moisture content (um). The experiments were developed based on the methodological procedures of the ABNT NBR 14810:2002 standard. The particleboards were manufactured by hot-pressing at 4MPa and 90°C, using timber particles with 5% of moisture content and 10% of monocomponent and bicomponent polyurethane resin. The higher moisture content was achieved when the monocomponent polyurethane resin was used. The bicomponent polyurethane resin provided a percent increase of 43.7% and 22.7% on the modulus of rupture and apparent density, respectively, when compared to the standard limit. The internal adhesion of the panels manufactured with monocomponent resin was 2.45 times higher than the standard limit. The confidence interval between means revealed that the internal adhesion and apparent density exhibited statistical equivalence. A good correlation between the internal adhesion and apparent density was found, for this reason it was possible to estimate the internal adhesion of the panels based on the apparent density data.
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The purpose of this study was to evaluate the physical and mechanical properties of particleboard made with pruning wastes from Ipê (Tabebuia serratifolia) and Chapéu-de-Sol (Terminalia catappa) trees. Particleboards were prepared with both wood species, using all the material produced by grinding the pruning wastes. The particleboards had dimensions of 45×45 cm, a thickness of approximately 11.5 mm and an average density of 664 kg/m3. A urea-formaldehyde adhesive was used in the proportion of 12% of the dry particle mass. The particleboards were pressed at a temperature of 130 C for 10 mins. The physical and mechanical properties analyzed were density, moisture content, thickness swelling, percentage of lignin and cellulose, modulus of resilience, modulus of elasticity and tensile strength parallel to the grain, accordingly to the standards NBR 14810 and CS 236-66 (1968). The particleboards were considered to be of medium density. The particle size significantly affected the static bending strength and tensile strength parallel to the grain. Ipê presented better results, demonstrating a potential for the production and use of particleboard made from this species. © The Author(s) 2013.
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Thermal-oxidative degradation behaviours of raw natural rubber (NR) have been investigated by using thermogravimetry analysis in inert and oxidative atmospheres and the plasticity retention index (PRI). The activation energy E a, was calculated using Horowitz-Metzger and Coats-Redfern methods and compared with PRI. The E a values obtained by each method were in good agreement with each other. The June samples are the least stable rubbers among the studied ones, whereas February samples exhibited the highest values of activation energy, therefore in agreement with the PRI behaviour, which indicates that the thermo-oxidative stability of the June samples are the poorest during the thermo-oxidative degradation reaction. Natural rubber is a product of biological origin, and thus these variations in the values of thermal behaviour and PRI might be related to the genetic differences and alterations of climatic conditions that act directly on the synthesis of non-rubber constituents, which are generally reflected in latex and rubber properties. © 2013 Institute of Materials, Minerals and Mining.
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Pós-graduação em Design - FAAC
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)