1,141 research outputs found

    Perfil epidemiológico das agressões por arma de fogo e arma branca no interior da Bahia

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    O presente estudo teve como objetivo traçar o perfil epidemiológico das agressões por arma de fogo e arma branca, no período de 2009 a 2011, em um Hospital Geral no interior da Bahia. Trata-se de um estudo descritivo, transversal, elaborado a partir de dados secundários de hospitalizações por agressão, nos anos de 2009 à 2011, no Hospital Geral Prado Valadares (HGPV) em Jequié, Bahia. A análise foi realizada por meio de estatística descritiva e os dados apresentados em frequências absolutas e relativas. Dos resultados obtidos, 299 hospitalizações se deram por agressão por arma de fogo e arma branca, sendo o maior percentual de vítimas, jovens do sexo masculino, na faixa etária entre 20-29 anos (39,5%). É necessário a elaboração e implementação de políticas públicas envolvendo os diversos segmentos da sociedade civil e organizada para o enfrentamento deste problema de saúde pública com vistas a adoção de estratégias de prevenção e redução dos índices de morbimortalidade

    Friction Stir Welding Of Duplex And Superduplex Stainless Steels And Some Aspects Of Microstructural Characterization And Mechanical Performance

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Friction stir welding was used to produce butt joints on 6 mm thick plates of UNS S32101 lean duplex stainless steel, S32205 duplex stainless steel, and S32750 and S32760 superduplex stainless steels. Fully consolidated joints were achieved, with full penetration, using heat input of 1.37-1.50 kJ/mm. Specimens submitted to tensile testing performed perpendicular to the welding direction showed failure on the base metal, reflecting better mechanical performance of the welded joints. Furthermore, tensile testing along the joints revealed higher yield and tensile strengths in all cases, as well as increased elongation. Microstructural evaluation showed that there was pronounced grain refinement in the welded joints of all the materials studied, achieving grain sizes as small as 1 mu m. The differences in the ferrite and austenite grain sizes in the stir zone, such as the degree of grain refinement, could be explained by the combination of dynamic recrystallization of austenite during the welding process and the recrystallization and growth of the ferrite grains, promoted firstly by the severe deformation and secondly by the high temperature inherent to the FSW process. Superduplex stainless steel FSW joints were more able to maintain a balanced microstructure, compared to conventional and lean duplex stainless steels, due to greater homogeneity of recrystallization in the welded joint.191117131PetrobrasFINEPCNPqFAPESPConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Effects of organic/inorganic amendments on trace elements dispersion by leachates from sulfide-containing tailings of São Domingos mine, Portugal. Time evaluation

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    Greenhouse pot experiments were conducted over 13 months to evaluate the effect of two amendment mixture doses (30 and 75 Mg/ha) on the geochemical dispersion of trace elements by leaching hazardous mine wastes from the São Domingos mine. Mineralogical evolution of these materials was also evaluated. Amendment mixtures containing solid wastes from agriculture (plant remains + strawberry substrate and rockwool used for the strawberry crop) and fromdistillation of Ceratonia siliqua L. and Arbutus unedo L. fruitswere used to improve the chemical characteristics of leachates fromsulfide minewastes. Sulfide mine wastes had acidic characteristics, aswell as high electrical conductivity and total element concentrations (g/kg; Al: 54.8–61.2; Fe: 104.0–110.0; Pb: 9.0–13.8; S: 63.6–68.0; As: ≈1). These features contributed to the large capacity for leaching of hazardous elements during, at least, the first fourmonths of incubation. In the seventh month of incubation, therewas a significant decrease in the leachate concentration of the majority of hazardous elements. The addition of amendments minimised trace element dispersion in leachate percolation during the first seven months (25 to 99% reduction compared to control, depending on the element and sampling period). However, the leachate characteristics were not influenced by amendment doses and no significant differences were observed in leachate composition (control and amended treatments) after 13 months. Amendment application led to differences between the solid phases of the efflorescent salts formed on the surface of the control and the amended treatments. The efflorescent salts contained very soluble aluminium sulfates, together with alunite–jarosite-group solid phases in amended samples, and copiapite-group solid phases in control. In the core materials (5 to 10 cmin depth), themineralogy was similar in both control and amended samples. The presence of various stable solid phases from alunite– jarosite-group, such as jarosite and beudantite (mainly in deeper materials), can explain the low concentrations of trace elements in the leachates after thirteen monthsinfo:eu-repo/semantics/publishedVersio

    Use of combined tools for effectiveness evaluation of tailings rehabilitated with designed Technosol

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    Soil and water characteristics and biogeochemical processes can be improved by the application of an integrated technology based on circular economy: designed Technosol. The evaluation of the effectiveness of the superficial application of a designed Technosol, with andic and eutrophic properties, on the rehabilitation of sulfide tailings of a uranium mine (Fe´ mining area, Spain) was the aim of this study. After 20 months of the Technosol application, the tailing rehabilitation status (Rehabilitated tailing) was compared to a non-rehabilitated tailing (Tailing). To assess the rehabilitation of these systems, several properties were analyzed: chemical characteristics of the materials and their leachates, soil enzymatic activities (dehydrogenase, b-glucosidase, acid phosphatase and urease), basal respiration and several plant endpoints from direct and indirect bioassays and pot experiment using Lolium perennse L. and Trifolium pratense L.. Potentially toxic concentrations of Co, Mn and Ni were identified in both available fraction and leachates, pointing out the serious environmental risk posed by the tailing. The improvement of overall physicochemical properties in the rehabilitated tailing materials (e.g., decrease of the hazardous element concentrations in leachates and available fraction, and improvement of the fertility and structure) allowed a quick plant cover with pasture species and provided a suitable habitat for active microbial community (evaluated by increasing dehydrogenase activity and basal respiration). This improvement in the rehabilitated tailing contributed to a significant decrease in the ecotoxicological risk and the spread of hazardous elements. The field application of this specific Technosol was a promising and lasting solution for rehabilitation of this type of tailingsinfo:eu-repo/semantics/publishedVersio

    Friction Stir Welding Of Duplex Stainless Steels

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    Duplex stainless steels are successful in a variety of applications such as the food industry, petrochemical and plants for desalination of seawater, where high corrosion resistance and high mechanical strength are required. However, the beneficial microstructure may be change during fusion welding steps and it can compromise the performance of these materials. Friction stir welding is a solid state process avoiding typical problems concerning solidification such as solidification cracks, liquation and segregation of alloying elements. For superduplex stainless steels can avoid unbalanced proportions of ferrite and austenite, formation of secondary deleterious phases and grain growth of ferrite in the heat affected zone. Consolidated friction stir welded joints with full penetration of 6 mm thick were obtained for UNS S32101 and S32205 duplex and S32750 and S32760 superduplex stainless steels. The friction stir welds were submitted to tensile tests indicating an improvement of strength in welded joints showing increased of yield and tensile strength for all studied cases. Regarding the microstructural characterization, an outstanding gran refinement was observed in the welded joint achieving grain sizes as small as 1 mu m. This refinement was associated with the combination of microstructural restoration mechanisms in the dual phase microstructure promoted by severe deformation associated with a high temperature during the welding process.211596

    Friction Stir Welding of Duplex Stainless Steels

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    Duplex stainless steels are successful in a variety of applications such as the food industry, petrochemical and plants for desalination of seawater, where high corrosion resistance and high mechanical strength are required. However, the beneficial microstructure may be change during fusion welding steps and it can compromise the performance of these materials. Friction stir welding is a solid state process avoiding typical problems concerning solidification such as solidification cracks, liquation and segregation of alloying elements. For superduplex stainless steels can avoid unbalanced proportions of ferrite and austenite, formation of secondary deleterious phases and grain growth of ferrite in the heat affected zone. Consolidated friction stir welded joints with full penetration of 6 mm thick were obtained for UNS S32101 and S32205 duplex and S32750 and S32760 superduplex stainless steels. The friction stir welds were submitted to tensile tests indicating an improvement of strength in welded joints showing increased of yield and tensile strength for all studied cases. Regarding the microstructural characterization, an outstanding gran refinement was observed in the welded joint achieving grain sizes as small as 1 ?m. This refinement was associated with the combination of microstructural restoration mechanisms in the dual phase microstructure promoted by severe deformation associated with a high temperature during the welding process.Os aços inoxidáveis duplex são bem sucedidos em uma variedade de aplicações como a indústria alimentícia, petroquímica e para plantas de dessalinização da água do mar, onde alta a resistência à corrosão e alta resistência mecânica são exigidas. Contudo, durante operações de soldagem por fusão pode haver alteração da microestrutura favorável destes materiais comprometendo seu desempenho. O processo de soldagem por atrito com pino não consumível pode gerar juntas no estado sólido evitando os típicos problemas da solidificação da poça fundida como segregação de elementos de liga, formação de trincas de solidificação e liquação; para o caso de aços inoxidáveis superduplex, pode-se evitar proporções desbalanceadas de ferrita e austenita, formação de fases secundárias deletérias e crescimento de grão ferrítico na zona termicamente afetada. Juntas consolidadas com penetração completa foram obtidas usando chapas de 6 mm de espessura para os aços inoxidáveis duplex UNS S32101 e S32205 e superduplex S32750 e S32760. As amostras foram submetidas a ensaios de tração indicando uma melhoria do desempenho mecânica das juntas soldadas com o aumento da tensão de escoamento e do limite de resistência à tração para todos os casos. Em relação à caracterização microestrutural, um pronunciado refinamento da ordem de 1 ?m foi observado na junta soldada. Este refinamento foi associado à combinação de mecanismos de restauração na microestrutura bifásica promovida pela deformação severa junto com a alta temperatura durante o processo de soldagem.211596

    Friction stir welding of duplex and superduplex stainless steels and some aspects of microstructural characterization and mechanical performance

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    Friction stir welding was used to produce butt joints on 6 mm thick plates of UNS S32101 lean duplex stainless steel, S32205 duplex stainless steel, and S32750 and S32760 superduplex stainless steels. Fully consolidated joints were achieved, with full penetration, using heat input of 1.37-1.50 kJ/mm. Specimens submitted to tensile testing performed perpendicular to the welding direction showed failure on the base metal, reflecting better mechanical performance of the welded joints. Furthermore, tensile testing along the joints revealed higher yield and tensile strengths in all cases, as well as increased elongation. Microstructural evaluation showed that there was pronounced grain refinement in the welded joints of all the materials studied, achieving grain sizes as small as 1 µm. The differences in the ferrite and austenite grain sizes in the stir zone, such as the degree of grain refinement, could be explained by the combination of dynamic recrystallization of austenite during the welding process and the recrystallization and growth of the ferrite grains, promoted firstly by the severe deformation and secondly by the high temperature inherent to the FSW process. Superduplex stainless steel FSW joints were more able to maintain a balanced microstructure, compared to conventional and lean duplex stainless steels, due to greater homogeneity of recrystallization in the welded joint.191117131FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçã

    The Potential of Cistus salviifolius L. to Phytostabilize Gossan Mine Wastes Amended with Ash and Organic Residues

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    The São Domingos mine is within the Iberian Pyrite Belt, a mining district with large concentrations of polymetallic massive sulfide deposits. Mine waste heaps are considered extreme environments, since they contain high total concentrations of potentially hazardous elements (PHE), which contribute to inhibiting the development of most plants. Autochthonous plant species, such as Cistus salviifolius L., are able to grow naturally in this degraded environment, and may contribute to minimizing the negative chemical impacts and improving the landscape quality. However, the environmental rehabilitation processes associated with the development of these plants (phytostabilization) are very slow, so the use of materials/wastes to improve some physicochemical properties of the matrix is necessary in order to speed up the process. This work studied the effectiveness of the phytostabilization with C. salviifolius of gossan mine wastes from the mine of São Domingos amended with organic and inorganic wastes in order to construct Technosols. The mine wastes have an acid pH ( 3.5), high total concentrations of PHE and low concentrations of organic C and available nutrients. The best vegetative development occurred without visible signs of toxicity in the Technosols containing a mixture of agriculture residues. These treatments allowed the improvement of the soil-plant system providing a better plant cover and improved several chemical properties of mine wastes, helping to speed up the environmental rehabilitationinfo:eu-repo/semantics/publishedVersio

    Friction stir welding of duplex stainless steels

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    Os aços inoxidáveis duplex são bem sucedidos em uma variedade de aplicações como a indústria alimentícia, petroquímica e para plantas de dessalinização da água do mar, onde alta a resistência à corrosão e alta resistência mecânica são exigidas. Contudo, durante operações de soldagem por fusão pode haver alteração da microestrutura favorável destes materiais comprometendo seu desempenho. O processo de soldagem por atrito com pino não consumível pode gerar juntas no estado sólido evitando os típicos problemas da solidificação da poça fundida como segregação de elementos de liga, formação de trincas de solidificação e liquação; para o caso de aços inoxidáveis superduplex, pode-se evitar proporções desbalanceadas de ferrita e austenita, formação de fases secundárias deletérias e crescimento de grão ferrítico na zona termicamente afetada. Juntas consolidadas com penetração completa foram obtidas usando chapas de 6 mm de espessura para os aços inoxidáveis duplex UNS S32101 e S32205 e superduplex S32750 e S32760. As amostras foram submetidas a ensaios de tração indicando uma melhoria do desempenho mecânica das juntas soldadas com o aumento da tensão de escoamento e do limite de resistência à tração para todos os casos. Em relação à caracterização microestrutural, um pronunciado refinamento da ordem de 1 μm foi observado na junta soldada. Este refinamento foi associado à combinação de mecanismos de restauração na microestrutura bifásica promovida pela deformação severa junto com a alta temperatura durante o processo de soldagem2115969CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFINANCIADORA DE ESTUDOS E PROJETOS - FINEPFUNDAÇÃO DE AMPARO À CIÊNCIA E TECNOLOGIA DO ESTADO DE PERNAMBUCO - FACEPEFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informaçãoSem informaçãoSem informaçãoDuplex stainless steels are successful in a variety of applications such as the food industry, petrochemical and plants for desalination of seawater, where high corrosion resistance and high mechanical strength are required. However, the beneficial microstructure may be change during fusion welding steps and it can compromise the performance of these materials. Friction stir welding is a solid state process avoiding typical problems concerning solidification such as solidification cracks, liquation and segregation of alloying elements. For superduplex stainless steels can avoid unbalanced proportions of ferrite and austenite, formation of secondary deleterious phases and grain growth of ferrite in the heat affected zone. Consolidated friction stir welded joints with full penetration of 6 mm thick were obtained for UNS S32101 and S32205 duplex and S32750 and S32760 superduplex stainless steels. The friction stir welds were submitted to tensile tests indicating an improvement of strength in welded joints showing increased of yield and tensile strength for all studied cases. Regarding the microstructural characterization, an outstanding gran refinement was observed in the welded joint achieving grain sizes as small as 1 μm. This refinement was associated with the combination of microstructural restoration mechanisms in the dual phase microstructure promoted by severe deformation associated with a high temperature during the welding proces
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