Estudo da molhabilidade de ligas de adição à base de prata sobre insertos cerâmicos para aplicação em brocas perfuração de poços de petróleo

Metal-ceramic interfaces are present in tricone drill bits with hard ceramic inserts for oil well drilling operations. The combination of actions of cutting, crushing and breaking up of rocks results in the degradation of tricone drill bits by wear, total or partial rupture of the drill bit body or the ceramic inserts, thermal shock and corrosion. Also the improper pressfitting of the ceramic inserts on the bit body may cause its total detachment, and promote serious damages to the drill bit. The improvement on the production process of metal-ceramic interfaces can eliminate or minimize some of above-mentioned failures presented in tricone drill bits, optimizing their lifetime and so reducing drilling metric cost. Brazing is a widely established technique to join metal-ceramic materials, and may be an excellent alternative to the common mechanical press fitting process of hard ceramic inserts on the steel bit body for tricone drill bit. Wetting phenomena plays an essential role in the production of metal/ceramic interfaces when a liquid phase is present in the process. In this work, 72Silver-28Copper eutectic based brazing alloys were melted onto zirconia, silicon nitride and tungsten carbide/Co substrates under high vacuum. Contact angle evolution was measured and graphically plotted, and the interfaces produced were analysed by SEM-EDX. The AgCu eutectic alloy did not wet any ceramic substrates, showing high contact angles, and so without chemical interaction between the materials. Better results were found for the systemns containing 3%wt of titanium in the AgCu alloy. The presence os titanium as a solute in the alloy produces wettable cand termodinamically stable compounds, increasing the ceramics wetting beahviour

Antígenos da forma amastigota de Leishmania chagasi identificados por dupla varredura da biblioteca de cDNA

Control of human visceral leishmaniasis in endemic regions is hampered in part by the lack of knowledge with respect of the role reservoirs and vector. In addition, there is not yet an understanding of how non-symptomatic subclinical infection might influence the maintenance of infection in a particular locality. Of worrisome is the limited accessibility to medical care in places with emerging drug resistance. There is still no available protective vaccine either for humans or other reservoirs. Leishmania species are protozoa that express multiple antigens which are recognized by the vertebrate immune system. Since there is not one immunodominant epitope recognized by most hosts, strategies must be developed to optimize selection of antigens for prevention and immunodiagnosis. For this reason, we generated a cDNA library from the intracellular amastigote form of Leishmania chagasi, the causative agent of South American visceral leishmaniasis. We employed a two-step expression screen of the library to systematically identify T and T-dependent B cell antigens. The first step was aimed at identifying the largest possible number of clones producing an epitope-containing polypeptide with a pool of sera from Brazilians with documented visceral leishmaniasis. After removal of clones encoding heat shock proteins, positive clones underwent a second step screen for their ability to cause proliferation and IFN-γ responses of T cells from immune mice. Six unique clones were selected from the second screen for further analysis. The clones encoded part of the coding sequence of glutamine synthetase, transitional endoplasmic reticulum ATPase, elongation factor 1γ, kinesin K-39, repetitive protein A2, and a hypothetical conserved protein. Humans naturally infected with L. chagasi mounted both cellular and antibody responses to these protein Preparations containing multiple antigens may be optimal for immunodiagnosis and protective vaccines against Leishmania

Maternidade e sindrome do down: Um estudo sobre o sentimento vinculado frente ao diagnóstico

Trata-se de um estudo de delineamento transversal de caráter multidisciplinar, o qual conta com um estatístico que contribuiu para o delineamento do estudo, realizando o cálculo amostral e contribuindo efetivamente para análise dos dados e alunos de psicologia e pediatrias que contribuíram para a coleta de dados. A literatura aponta que a transmissão inadequada do diagnóstico da Síndrome de Down pode prejudicar o vínculo mãe-bebê e o posterior desenvolvimento da criança. Sendo assim, este estudo objetivou analisar os sentimentos maternos frente a este diagnóstico, verificando diferentes formas de transmissão e possíveis facilitadores da aceitação da Síndrome. A amostra foi constituída por 20 mães cujos filhos apresentam Síndrome de Down, na faixa etária de 0 à 03 anos e que recebem atendimento em ambulatório de um Hospital Universitário de Pediatria. Para coleta dos dados fez-se uso de um questionário, após a assinatura do Termo de Consentimento Livre e Esclarecido. Os dados foram analisados através de dois softwares de processamento de dados, o SPSS e o ALCESTE (Análise Lexical por Contexto de um Conjunto de Segmento de Texto). Os dados indicaram que 90% das mães receberam o diagnóstico de Síndrome de Down depois do parto. 75% dos diagnósticos foram comunicados pelo médico pediatra e 15% pelas enfermeiras. As mãe referiram que o diagnóstico foi tardio, inadequado e insuficiente no informativo. Observouse que as entrevistadas viveram os mesmos sentimentos observados na literatura como: choque, negação, tristeza e ira, adaptação e reorganização. Tais resultados permitem concluir que o diagnóstico de SD nas mães investigadas foi em sua maioria tardio, realidade comum no Brasil, principalmente quando se trata de classes econômicas baixas. As mães apontam que percebem este diagnóstico como tardio, inadequado e insuficiente no informativo, e gera sentimentos que a literatura já cita como comuns frente a esse tipo de diagnóstico. Portanto, observamos que a notícia pode ser um fator que dificulte ou facilite o estabelecimento do vínculo mãe-bebê, comprometendo a busca de recursos para o desenvolvimento da criança

Fatores que afetam a germinação e a emergência de Xanthium strumarim L.: dormência, qualidade da luz e profundidade de semeadura

Foram conduzidos três ensaios com o objetivo de estudar os efeitos de diferentes métodos de quebra de dormência das sementes, da qualidade da luz e da profundidade de semeadura na germinação e emergência do Xanthium strumarim L. (carrapichão). No primeiro ensaio, sob condições de câmara de crescimento, os tratamentos constaram de 5 métodos de quebra de dormência: mecânico (lixa), químico (H2SO4 conc. por 10 min.), pré-tratamento em água (imersão por 2 horas), físico (choque térmico: água à 80oC por 2 min.) e testemunha, que proporcionaram 100%, 93%, 93%, 87% e 80% de germinação, respectivamente, sem haver diferença estatística entre os mesmos. O pré-tratamento em água apresentou menor índice de velocidade de germinação (IVG) e os demais não diferiram significativamente entre si. No segundo ensaio, também sob condições de câmara de crescimento, os tratamentos de qualidade da luz constaram de 6 filtros de luz, que resultaram nas seguintes porcentagens de germinação: azul - com refletividade máxima a 450 nm (13%), verde-500 nm (33%), vermelho-700 nm (13%), vermelho/distante-760 nm (7%), ausência de luz (26%) e transparente - sem absortividade na região de 380 a 760 nm (testemunha, 73%), indicando sensibilidade das sementes à qualidade de luz. No terceiro ensaio, sob condições de casa-de-vegetação, os tratamentos foram diferentes profundidades de semeadura (0 a 20 cm, em intervalos de 2 cm), sendo que o máximo de emergência ocorreu no intervalo de 0 a 8 cm, no qual foi observado 67% de emergência do carrapichão, com maior índice de velocidade emergência (IVE), sendo que após os 16 cm, praticamente não houve emergência.

Thermal and mechanical shocks affecting the first flush of production of Lentinula edodes on Eucalyptus saligna logs

O objetivo deste trabalho foi avaliar o efeito do choque térmico e mecânico na produtividade de Lentinula edodes em 140 toras de Eucalyptus saligna, completamente colonizadas pelo fungo, em diferentes tempos de imersão em água e no primeiro fluxo de produção. As toras foram imersas em água resfriada (16ºC) ou à temperatura ambiente (22ºC); os períodos de imersão corresponderam a 6, 10, 14, 18, 22, 26 e 38 horas; o choque mecânico foi acompanhado por três quedas consecutivas da tora, em posição vertical, no chão. A temperatura da água e o tempo de imersão afetaram a produção de L. edodes, resultando em aumentos significativos (2 a 4 vezes) nos tratamentos em que as toras foram submetidas à água resfriada e nos tempos de imersão mais curtos (6 e 10 horas). O choque mecânico não resultou em aumento na produção de basidiomas.

Caracterização ecofisiológica de sementes de espécies lenhosas da Caatinga

Dormancy is an inherent property of the seeds that define the environmental conditions in which they are able to germinate and their presence is an adaptive trait common in species inhabiting semiarid regions. Moreover, the ability of seedling establishment in these environments has been related to the size, strength and chemical characteristics of the seeds. This study investigated patterns of dormancy and germination speed in tree species of the Caatinga, exploring how the seed size influence the processes of germination, seedling size and biomass allocation. In addition, we aim to investigate the chemical characteristics of the reserves, to verify a possible relationship between nutritional content and the process of seed germination. Therefore, seeds were collected from ten species of woody Caatinga for tests of breaking dormancy, germination and biochemical characterization. Overall, the results show that the scarification treatments mechanical and chemical, and thermal shock influenced the percentage and speed of germination in 50 % of the species, suggesting that they have some level of physical dormancy in the seeds. Biochemical characterization showed the existence of large amounts of carbohydrates in the seeds of all species, low proportion of protein and low amounts of neutral lipids. Using linear regression, we demonstrated the existence of a significant relationship between seed size and the ratio of root/shoot where the largest seeds invested a greater amount of resources for shoot growth. The relationship between germination speed and non-reducing sugar content was also significant, so these compounds is related to the maintenance of physiological seed quality. These results confirm some relationships discussed in the literature for cultivated species, but can be applied to the species native to the Caatinga

Avaliação dos impactos do programa bolsa família na renda, na educação e no mercado de trabalho das famílias pobres do Brasil

This study aims to verify the impact of the Bolsa Família Program (BFP) in income and school attendance of poor Brazilian families. It is intended to also check the existence of a possible negative effect of the program on the labor market, titled as sloth effect. For such, microdata from the IBGE Census sample in 2010 were used. Seeking to purge possible selection biases, methodology of Quantilic Treatment Effect (QTE) was applied, in particular the estimator proposed by Firpo (2007), which assumes an exogenous and non-conditional treatment. Moreover, Foster- Greer-Thorbecke (FGT) index was calculated to check if there are fewer households below the poverty line, as well as if the inequality among the poor decreases. Human Opportunity Index (HOI) was also calculated to measure the access of young people / children education. Results showed that BFP has positively influenced the family per capita income and education (number of children aged 5-17 years old attending school). As for the labor market (worked hours and labor income), the program showed a negative effect. Thus, when compared with not benefiting families, those families who receive the BFP have: a) a higher family income (due to the shock of the transfer budget money) b) more children attending school (due to the conditionality imposed by the program); c) less worked hours (due to sloth effect in certain family groups) and d) a lower income from work. All these effects were potentiated separating the sample in the five Brazilian regions, being observed that the BFP strongly influenced the Northeast, showing a greater decrease in income inequality and poverty, and at the same time, achieved a greater negative impact on the labor market

Um estudo sobre o estágio supervisionado na formação inicial de professores de matemática na Bahia

This work arose from our concerns with the issues of teacher training for early childhood education. From the difficulties encountered as a novice teacher in elementary, we deem important to research training needs of these professionals. Thus, we define the objective of this research to investigate the training needs of novice teachers teaching Early Childhood Education/Elementary school. Our work fits in Educational Research Qualitative Approach, and its construction procedures of the semistructured interview data and document analysis. Our empirical field was made up of schools in the metropolitan region of Natal / RN, offering kindergarten / elementary school. The subjects are five teachers who act as holder of the elementary school class and have 0-3 years of teaching practice, characterizing the second Huberman (2007) as novice teachers. Data analysis, based on principles of content analysis, three themes emerged: Beginner Teaching Professor in Early Childhood Education / Preschool; Reasons explaining the difficulties Faculty / Formative Needs Teaching and Training in Early Childhood Education / Elementary school, from the Training Needs Analysis, with their respective categories, subcategories, contributing to our understanding of the subject matter. The entry into the profession is marked by mixed feelings of euphoria and fear, where there seems to be a "clash" with reality. The difficulties are related to the planning / execution of activities, meet the individual needs of learning and assessment of children. As a strategy to overcome the difficulties the teachers exercise the action-reflection-action in their practices and seek continuous updates in the theoretical and methodological framework of early childhood education. The reasons that define these difficulties may be related to the teacher, school, family, and students of these institutions. In experiencing these difficulties has outlined the need for teacher training, among which stand out studies on ethics in teaching with children, the concept of children and their childhoods, peculiarities of teaching / learning in preschool, toys and legal determinations on early childhood education, multi-language and expressions in early childhood education, specific content areas of knowledge, among others. Furthermore, studies on the theoretical as Piaget, Vigotsky, Maria Carmen Barbosa and Emily Smith. For these professionals to be a professional early childhood education is: like children, be patient and careful, have specific theoretical and practical training for teachers in kindergarten, being able to improvise with seriousness and competence and get updates on continuing education. The surveys, together with the authors and teachers, to confirm our understanding that the training needs of beginners may be related to shortcomings in the initial and continuing education

Necessidades de formação de professoras principiantes da educação infantil/pré-escola

This work arose from our concerns with the issues of teacher training for early childhood education. From the difficulties encountered as a novice teacher in elementary, we deem important to research training needs of these professionals. Thus, we define the objective of this research to investigate the training needs of novice teachers teaching Early Childhood Education/Elementary school. Our work fits in Educational Research Qualitative Approach, and its construction procedures of the semistructured interview data and document analysis. Our empirical field was made up of schools in the metropolitan region of Natal / RN, offering kindergarten / elementary school. The subjects are five teachers who act as holder of the elementary school class and have 0-3 years of teaching practice, characterizing the second Huberman (2007) as novice teachers. Data analysis, based on principles of content analysis, three themes emerged: Beginner Teaching Professor in Early Childhood Education / Preschool; Reasons explaining the difficulties Faculty / Formative Needs Teaching and Training in Early Childhood Education / Elementary school, from the Training Needs Analysis, with their respective categories, subcategories, contributing to our understanding of the subject matter. The entry into the profession is marked by mixed feelings of euphoria and fear, where there seems to be a "clash" with reality. The difficulties are related to the planning / execution of activities, meet the individual needs of learning and assessment of children. As a strategy to overcome the difficulties the teachers exercise the action-reflection-action in their practices and seek continuous updates in the theoretical and methodological framework of early childhood education. The reasons that define these difficulties may be related to the teacher, school, family, and students of these institutions. In experiencing these difficulties has outlined the need for teacher training, among which stand out studies on ethics in teaching with children, the concept of children and their childhoods, peculiarities of teaching / learning in preschool, toys and legal determinations on early childhood education, multi-language and expressions in early childhood education, specific content areas of knowledge, among others. Furthermore, studies on the theoretical as Piaget, Vigotsky, Maria Carmen Barbosa and Emily Smith. For these professionals to be a professional early childhood education is: like children, be patient and careful, have specific theoretical and practical training for teachers in kindergarten, being able to improvise with seriousness and competence and get updates on continuing education. The surveys, together with the authors and teachers, to confirm our understanding that the training needs of beginners may be related to shortcomings in the initial and continuing education

Esporos de Clostridium botulinum em mel comercializado no Estado de São Paulo e em outros Estados brasileiros

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da incorporação de cinzas de lodo de esgoto como adição mineral em concretos de cimento Portland

O desenvolvimento das grandes cidades tem gerado um dos maiores desafios ambientais enfrentados na atualidade, que é a gestão eficaz de resíduos sólidos. A grande variedade e quantidade dos resíduos produzidos diariamente, tem tornado a destinação ecologicamente correta e sustentável destes materiais cada vez mais difícil. Dentre os vários resíduos produzidos diariamente destacam-se os lodos oriundos de estações de tratamento de esgotos, denominados de lodos de esgoto, cuja destinação final segura tem sido discutida mundialmente em diversos estudos, tendo em vista que a tendência de geração deste tipo de resíduo tende a crescer com o aumento do saneamento das cidades. Uma forma amplamente difundida nos países desenvolvidos para destinação dos lodos de esgoto é a incineração destes materiais para posterior envio das cinzas geradas neste processo a aterros sanitários. Porém, tem-se estudado formas alternativas de disposição, destacando-se a utilização destas cinzas como adição mineral em concretos e argamassas de cimento Portland. Sabe-se que o desempenho de resíduos de incineração como adição mineral em matrizes cimentícias, depende em grande parte da capacidade de atuação destes materiais como elementos pozolânicos ou como fileres, podendo estas características serem influenciadas pela temperatura de queima ao qual estes resíduos foram submetidos. Neste sentido, verificou-se com esta pesquisa a influência da temperatura empregada na queima dos lodos sépticos no índice de atividade pozolânica (IAP) das cinzas geradas como resíduo deste processo, aqui denominadas de cinzas de lodo séptico (CLS), sendo em seguida, avaliadas as implicações técnicas e microestruturais da utilização deste resíduo em teores de 10%, 20% e 30% como adição mineral em concretos de cimento Portland. Os resultados obtidos demonstraram não haver alterações significativas no IAP das CLS em decorrência da temperatura utilizada durante o processo de queima dos lodos de esgoto. Além disso, verificou-se que embora a utilização das CLS tenham provocado diminuição da trabalhabilidade dos concretos para todos os teores de incorporação, estas melhoraram a resistência mecânica à compressão, o índice de vazios, a absorção de água e o comportamento microestrutural dos concretos contendo 10% e 20% de resíduo

Influência do Nível de Energia da Dieta sobre a Expressão Hepática de Hsp70-kDa em Frangos Submetidos ao Estresse Calórico Agudo

Este trabalho foi desenvolvido com o objetivo de pesquisar o efeito da energia da dieta sobre a temperatura do cólon e concentração de proteína de choque térmico (Hsp70) de frangos à temperatura ambiente, bem como durante o estresse calórico agudo. Os frangos foram criados até 51 dias de idade e alimentados com dietas contendo nível de energia alto (13.186 kJ EM/kg) ou baixo (12.139 kJ EM/kg). No 21º e 51º dias de idade, a temperatura do cólon foi medida e amostras de fígado foram obtidas para quantificação da Hsp70 através da análise por Western Blotting.. Nessas mesmas idades, a resposta das aves ao estresse calórico agudo (37º C/5 h) foi avaliada (temperatura colón e Hsp70 no fígado). Os resultados mostraram que aos 21 dias de idade, à temperatura ambiente, a temperatura do cólon e a concentração de Hsp70 hepática não foram afetadas pela energia da dieta, mas, aos 51 dias de idade, os frangos alimentados com baixos teores de energia apresentaram menores concentrações de Hsp70 no fígado. As respostas ao estresse calórico agudo mostraram que as aves alimentadas com dietas de alta energia tiveram menor incremento na temperatura do cólon, bem como no conteúdo de Hsp70 hepático. Os resultados desse estudo sugerem que a síntese de Hsp70 no fígado pode ser afetada pela energia da dieta e que frangos alimentados com altos níveis de energia podem ter a termotolerância alterada em condições de estresse agudo pelo calor.

Respostas Fisiológicas Associadas à Termotolerância em Pintos de Corte de Duas Linhagens por Exposição a Altas Temperaturas

Com o objetivo de se avaliar o comportamento fisiológico das aves, bem como, se ocorre a expressão da proteína do choque térmico (Hsp 70) no fígado e cérebro, como conseqüência da exposição ao estresse por calor, em quatro dias sucessivos (2 a 5 dias de vida), 20 pintos de corte de duas linhagens Pescoço pelado (Na/na) e Hubbard-Petersen, foram ou não estressados à temperatura de 36-37°C, durante cinco horas. Foram colhidas amostras de fígado e cérebro, ao final do período de estresse, e analisadas por Western Blotting, para determinação dos níveis de Hsp 70. Os resultados não mostraram associação entre perda de peso corporal e as demais características. Aumentos da variação de temperatura cloacal apresentaram aumentos nos níveis de Hsp70 no tecido hepático e cerebral. Concluiu-se que a concentração de Hsp70 no cérebro, apresentou-se correlacionada com a variação de temperatura cloacal, quando se usou o condicionamento ao calor em pintos de corte, embora não se possa afirmar que seria indicativo de termotolerância de aves.

Caracterização de cerâmicas porosas de alumina reforçada com zircônia produzidas pelo método da réplica

Porous ceramics have many applications: thermal insulation, catalytic support, materials to fire protection, filters, and others. There are many techniques to production of ceramic filters. One technique to obtain ceramic filters is the replication method. This method consists in the impregnation of polymeric foam with ceramic slurry followed by a heating treatment that will burn out the organic elements and sintering of the material, resulting of a replication of the original foam. To perform their functions ceramic filters must satisfy mechanical requirements and permeability parameters (darcian k1 and no-darcian k2). The permeability and the strength of the ceramic material are dependent of the pore size and pore distribution. To the use at high temperatures the evaluation of mechanical properties in these temperatures is necessary. In this work the mechanical behavior of two commercial porous ceramics (10 and 40 poros per inch) was studied these materials were submitted to compression and four-point flexure test (room temperature, at 1000 °C, after thermal shock). Density and porosity measurements, permeability tests and microstructural analysis by scanning electronic microscopy (SEM) were realized. The Results showed that the decrease of mechanical strength of these materials, when submitted to thermal shock, occur for propagation of new cracks from cracks pre-existing and the permeability depends of the pore size

Estudo do potencial refratário de argilas sílico-aluminosas do Rio Grande do Norte

The segment of the structural ceramics industry is one of the most important to the economy of Rio Grande do Norte. The supply chain makes a total of 206 companies that are distributed in 39 counties, concentrated in three regional centers: Seridó Apodi / Assu and great Natal. The ceramic industry in the state is around 80 million pieces per month, with 50,186 million of these tiles, which makes the Rio Grande do Norte one of the largest manufacturers of product in the Country. Different ceramic products can be manufactured by mixing two or more clays and accessory minerals. Mixtures acquire characteristics and form what is called the ceramic body. Refractory masses have a high melting point and thermal shock support. Its composition contains refractory clays with a little iron oxide and material fluxes. A line of semi-refractory ceramic products that stands out for its high added value are the bricks in ivory or red, used in building barbecues, fireplaces, wood stoves and braziers. The aim of this study was to use alumina-clay or silica- alumina-clay to the industrial RN, for the production of refractory bricks semi-refractory burning light. Clay and Kaolin were characterized for their chemical and mineralogical composition, immediately after ceramic bodies were made with different concentrations of the components, they were raised, pressed and sintered. After sintering the resulting products were characterized in terms of mechanical, thermal and dimensional than the characterization by X-ray diffraction and scanning electron microscopy. After obtaining the results, we concluded that the studied clay can be used for the production of semi-refractory bricks