Mechanical and tribological investigation of thin film coatings onto flexible polymeric substrate

Elastomers of the polydimethylsiloxane family are paramount to science and engineering due to their useful properties. Much work has gone into characterizing these polymers to optimize their performance. However, at this time there is little published literature dedicated to understanding and controlling its frictional behavior.In this study, Sylgard was characterized as a function of crosslinker ratio and curing temperature, then coated with Silastic using two different techniques resulting in a bilayer. The bilayer was characterized both in bulk and surface properties, and those results compared between techniques and uncoated Sylgard.It was demonstrated that spin coating can produce a well-bonded topcoat that possesses significantly lower frictional force than that of Sylgard alone at ambient and cryogenic temperatures. Changes in other properties were also quantified. This technique of PDMS surface modification may reduce the need of lubricants in mobile joints and extend component lifetime by shielding it from friction wear

Evaluation of inflammatory response induced by different types of daily contact lenses

Introduction: Contact lenses (CL) are biocompatible materials however, CL can also act as a vector for microorganisms to adhere and transfer to the ocular surface. Communal microorganisms that uneventfully cohabitate on lid margins and conjunctiva and potential pathogens that are found transiently on the ocular surface can adhere to CL in vivo. In the presence of reduced tissue resistance, these resident microorganisms or transient pathogens can invade and colonize the cornea or conjunctiva and produce inflammation or infection. Approximately two thirds of the isolated bacteria from CL-associated microbial keratitis are Gram-negative bacterial strains, most notably Pseudomonas aeruginosa but also some Serratia species, while one third comprises Gram-positive cocci, including Staphylococcus aureus and Staphylococcus epidermidi. Purpose: In order to access the inflammatory potential of daily disposable CL, the propose of this study was to evaluate the inflammatory response induced by different types of daily CL before and also after a normal daily wear. The inflammatory response can be measured by quantifying the Tumor Necrosis Factor alpha (TNF-α) produced by macrophages after contact with the CL. The microorganisms that are able to adhere to the CL are the major inducer of a possible inflammatory response, so microbiome of CL after the normal daily wear will also be evaluated. Methods: To establish the best incubation time to evaluate the pro-inflammatory potential of the daily weared CL (8 hours of wear), they were co-incubated with a macrophage cell culture for 3h, 8h and 14h and TNF-α in the supernatant of co-incubation was quantified by ELISA. Macrophage cell viability after co-incubation with CL was also accessed by lactate dehydrogenase (LDH) leakage assay. Results: The results showed that after 3h of co-incubation, only the positive control (containing LPS) showed a significant increase in TNF-α values. After 8h, of co-incubation the weared CL showed a significant increase of four times, while at 14h that increase was only of 2.5 times. Analysis of the LDH showed that at 14h of co- incubation more than 50% of the macrophage cells were death, contrary to 3 and 8 hour of co-incubation that showed viability values above 85%. Conclusion: These results indicated that the best incubation time to test the inflammatory potential of the CL wear 8 hours of co-incubation.info:eu-repo/semantics/publishedVersio

Effect of operational parameters and Pd/In catalyst in the reduction of nitrate using copper electrode

Water with high concentration of nitrate may cause damage to health and to the environment. This study investigated how concentration, current density, flow, pH, the use of Pd/In catalyst and operating mode (constant current density and constant cell potential) have an influence in the electrochemical reduction of nitrate and in the formation of gaseous compounds using copper electrode. Experiments were performed in two-compartment electrolytic cells separated by a cationic membrane with nitrate model solutions prepared as a surrogate of concentrated brines from membrane desalination plants. The results show that the electroreduction process has potential for reduction of nitrate and that it is influenced by the operational conditions. The best conditions found for the treatment - with satisfactory reduction of nitrate, formation of compounds and reproducibility - were at nitrate concentrations of 600 and 1000 mg.L-1, current density of 1.1 mA.cm-2 and without pH control, since in these conditions the production of gaseous compounds is higher than the production of nitrite. When Pd/In catalyst was used, the nitrate reduction was 50% after 6 hours of experiment and the predominant product were gaseous compounds. When compared to the experiment without the catalyst, the arrangement with Pd/In was the most efficient one.Fil: Beltrame, Thiago Favarini. Ufrgds Lacor; BrasilFil: Coelho, Vanessa. Ufrgds Lacor; BrasilFil: Marder, Luciano. Ufrgds Lacor; BrasilFil: Ferreira, Jane Zoppas. Ufrgds Lacor; BrasilFil: Marchesini, Fernanda Albana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Bernardes, Andrea Moura. Ufrgds Lacor; Brasi

Gestão de famílias : a mãe como foco da medicalização durante a gestação e o nascimento

A participação da mulher durante o pré-natal, sua adesão às orientações e a forma como vai exercer o cuidado envolvem um conjunto de interesses e possibilidades sociais. Devido a isso, investir em formas de controle desses corpos e gerenciar como irá gestar, parir, alimentar e cuidar da criança e da família adquirem importância. Tal modo de exercer o poder sobre a vida não encontra sustentação apenas no discurso médico ou político; requer uma articulação de práticas discursivas, ensinadas e reproduzidas por um complexo social que envolve desde a mídia até os profissionais de saúde, passando pelos familiares da gestante. Este artigo surge de uma pesquisa-intervenção em que foram realizadas oficinas de conversas com as gestantes que faziam o pré-natal em um hospital filantrópico. Aqui, colocamos em análise o que é tido como norma social sobre o que é ser "boa mãe", entendendo como um dispositivo de governo das famílias.The participation of women in prenatal care, their adherence to orientations and the way they will take care of their children involve a myriad of social interests and possibilities. As a result, both investing in ways of control and managing the way they will gestate, give birth, feed and take care of their children become important. Such way of exerting power over life has not only been supported by either the medical or political discourse; it has also required an articulation of discursive practices that are taught and reproduced by a social complex involving the media, health professionals and the pregnant women's families. This paper has stemmed from an intervention-research in which conversation workshops were carried out with pregnant women receiving prenatal care at a philanthropic hospital. Here, we analyze what has been regarded as a social norm of what means to be a "good mother", by understanding such norm as a device intended to govern families

O Retorno Financeiro dos Egressos da Universidade de Brasília – 1995 a 2015: Uma análise de salários

O presente estudo teve por objetivo principal estudar o retorno financeiro à educação fornecido pela Universidade de Brasília, a partir da remuneração dos egressos de graduação, dos últimos 21 anos da Universidade de Brasília. Foram levantados os dados sobre formados em graduação pela UnB entre os anos de 1995 a 2015, com levantamentos junto à Relação Informações Sociais-RAIS- do Ministério do Trabalho e Emprego. Conclui-se que a remuneração aumenta ao longo dos anos, à medida que os egressos vão obtendo mais experiência na carreira e que a diferença de remuneração entre cursos tende a diminuir aos longos dos anos, sinalizando uma boa qualidade do aluno oriundo da UnB, em qualquer área de atuação

Management of Families: the Mother as a Focus of Medicalization During Pregnancy and Childbirth

A participação da mulher durante o pré-natal, sua adesão às orientações e a forma como vai exercer o cuidado envolvem um conjunto de interesses e possibilidades sociais. Devido a isso, investir em formas de controle desses corpos e gerenciar como irá gestar, parir, alimentar e cuidar da criança e da família adquirem importância. Tal modo de exercer o poder sobre a vida não encontra sustentação apenas no discurso médico ou político; requer uma articulação de práticas discursivas, ensinadas e reproduzidas por um complexo social que envolve desde a mídia até os profissionais de saúde, passando pelos familiares da gestante. Este artigo surge de uma pesquisa-intervenção em que foram realizadas oficinas de conversas com as gestantes que faziam o pré-natal em um hospital filantrópico. Aqui, colocamos em análise o que é tido como norma social sobre o que é ser "boa mãe", entendendo como um dispositivo de governo das famílias.A participação da mulher durante o pré-natal, sua adesão às orientações e a forma como vai exercer o cuidado envolvem um conjunto de interesses e possibilidades sociais. Devido a isso, investir em formas de controle desses corpos e gerenciar como irá gestar, parir, alimentar e cuidar da criança e da família adquirem importância. Tal modo de exercer o poder sobre a vida não encontra sustentação apenas no discurso médico ou político; requer uma articulação de práticas discursivas, ensinadas e reproduzidas por um complexo social que envolve desde a mídia até os profissionais de saúde, passando pelos familiares da gestante. Este artigo surge de uma pesquisa-intervenção em que foram realizadas oficinas de conversas com as gestantes que faziam o pré-natal em um hospital filantrópico. Aqui, colocamos em análise o que é tido como norma social sobre o que é ser "boa mãe", entendendo como um dispositivo de governo das famílias.A participação da mulher durante o pré-natal, sua adesão às orientações e a forma como vai exercer o cuidado envolvem um conjunto de interesses e possibilidades sociais. Devido a isso, investir em formas de controle desses corpos e gerenciar como irá gestar, parir, alimentar e cuidar da criança e da família adquirem importância. Tal modo de exercer o poder sobre a vida não encontra sustentação apenas no discurso médico ou político; requer uma articulação de práticas discursivas, ensinadas e reproduzidas por um complexo social que envolve desde a mídia até os profissionais de saúde, passando pelos familiares da gestante. Este artigo surge de uma pesquisa-intervenção em que foram realizadas oficinas de conversas com as gestantes que faziam o pré-natal em um hospital filantrópico. Aqui, colocamos em análise o que é tido como norma social sobre o que é ser "boa mãe", entendendo como um dispositivo de governo das famílias.The participation of women in prenatal care, their adherence to orientations and the way they will take care of their children involve a myriad of social interests and possibilities. As a result, both investing in ways of control and managing the way they will gestate, give birth, feed and take care of their children become important. Such way of exerting power over life has not only been supported by either the medical or political discourse; it has also required an articulation of discursive practices that are taught and reproduced by a social complex involving the media, health professionals and the pregnant women's families. This paper has stemmed from an intervention-research in which conversation workshops were carried out with pregnant women receiving prenatal care at a philanthropic hospital. Here, we analyze what has been regarded as a social norm of what means to be a "good mother", by understanding such norm as a device intended to govern families

The role of Dark Matter interaction in galaxy clusters

We consider a toy model to analyze the consequences of dark matter interaction with a dark energy background on the overall rotation of galaxy clusters and the misalignment between their dark matter and baryon distributions when compared to {\Lambda}CDM predictions. The interaction parameters are found via a genetic algorithm search. The results obtained suggest that interaction is a basic phenomenon whose effects are detectable even in simple models of galactic dynamics.Comment: RevTeX 4.1, 5 pages, 3 figure

Petrographic evaluation of a 50-year-old concrete pavement made with quartzitic aggregate

A 50-year-old pavement from the city of La Plata (Province of Buenos Aires, Argentina), which had recently been replaced due to significant deterioration (cracks, sinking, etc.), was examined. The aim of the present work was to conduct a petrographic analysis of the concrete, in order to identity the causes leading to pavement failure. Petrographic studies were performed on two slabs and thin sections (ASTM C 856). The coarse and fine aggregate characteristics, the mortar and the paste–aggregate interface were examined, and the reaction products were analysed by XRD and SEM–EDS. The coarse aggregate is an orthoquartzite composed of angular quartz, with some particles exhibiting undulatory extinction, rare argillaceous matrix and microcrystalline siliceous, micaceous and/or ferruginous cement. The fine aggregate is natural siliceous sand. Commonly unfilled microcracks in the mortar and in some interfaces, as well as carbonated zones, were observed. Ettringite in entrained air voids was identified by XRD and SEM–EDS. No evidence of deleterious reaction development (e.g. ARS) was found. Concrete failure was attributed to high heavy traffic as it is an access area to La Plata port and the city