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Search Results: 1 - 10 of 211798 matches for " Flavia F. F. da Silva "
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Morphology and Thermal Properties of Core-Shell PVA/PLA Ultrafine Fibers Produced by Coaxial Electrospinning  [PDF]
Raquel P. Gon?alves, Flavia F. F. da Silva, Paulo H. S. Picciani, Marcos L. Dias
Materials Sciences and Applications (MSA) , 2015, DOI: 10.4236/msa.2015.62022
Abstract: Coaxial electrospinning process was used to produce biodegradable membranes made of coreshell fibers of a poly(lactic acid) (PLA) shell and a poly(vinyl alcohol) (PVA) core. Scanning electron microscopy analyses of these structures showed that the PLA shell can present certain porosity depending on the process condition. FTIR-ATR and contact angle measurements also suggested imprisonment of the PVA core within the PLA shell. This type of structure was also confirmed by means of transmissions electron microscopy. The morphology of these fibers was dependent on the flow rate of both core and shell solutions, and homogeneous and smooth surface was only attained when the flow rate of the external PLA solution was 4 times the flow rate of the internal PVA solution. The increase in the PLA solution flow rate increases the diameter of the core-shell fiber which reaches up to 1.7 μm. Nevertheless, fibers with smaller average diameter could also be produced (200 nm). These core-shell fibers presented improved hydrophilicity as compared with monolithic PLA fibers.
Respostas fisiológicas e perceptuais obtidas durante a caminhada em ritmo autosselecionado por mulheres com diferentes índices de massa corporal
Elsangedy, Hassan M.;Krinski, Kleverton;Buzzachera, Cosme F.;Nunes, Renan F. H.;Almeida, Flavia A. M.;Baldari, Carlo;Guidetti, Laura;Campos, Wagner de;Silva, Sergio G. da;
Revista Brasileira de Medicina do Esporte , 2009, DOI: 10.1590/S1517-86922009000500011
Abstract: physiological and perceived responses verified during gait have been widely studied; however, few investigations have tried to compare these responses in groups of different body mass indices during gait in self-selected rhythm. the aim of the present study was to compare the physiological and perceived responses among normative (n), overweighed (ow) and obese (ob) women during gait in self-selected rhythm. sixty-six sedentary women, aged between 20 and 45 years and divided in three groups according to their body mass indices participated in the study: (i) n (18.5 - 24.9kg·m-2, n = 22); (ii) ow (25.0 - 29.9kg·m-2, n = 22) and (iii) ob (> 30.0kg·m-2, n = 22). each participant performed a familiarization session and two experimental sessions (maximal incremental test and 20m-walking test in self-selected rhythm) to determine the physiological (heart rate - hr and oxygen consumption - o2) and perceived responses (perceived exertion - pe) of each session. one-way anova was applied to compare the physiological and perceived responses obtained during gait in self-selected rhythm among the three experimental protocols, applying the tukey's post hoc test with p < 0.05. although the obese subjects have registered lower walking velocity (1.30 ± 0.13m·s-1) compared with the normative and overweighed ones (1.69 ± 0.11 and 1.58 ± 0.22m·s-1, respectively) (p < 0.05), they presented similar physiological response ((58.7 ± 8.6; 63.1 ± 12.6; 64.8 ± 11.1 %o2 and 75.1 ± 7.8; 78.8 ± 8.5; 78.7 ± 7.2 %hrmax, for the normative, overweighed and obese groups, respectively). moreover, the perceived responses did not differ between experimental groups (11.6 ± 1.6; 11.7 ± 1.6; 12.2 ± 1.8, respectively). therefore, it can be concluded that regardless of the bmi, adult women present similar physiological and perceived responses during gait in self-selected rhythm even when walking in different velocities.
THE SYNTHESIS OF IMIDAZOLES VIA THE RADZISZEWSKI REACTION IN AQUEOUS MEDIA DIE Synthese von Imidazolen üBER DAS Radziszewski Reaktion in w ssrigen Medien
July A.Hernández Mu?oz,Bruno Dias de C. F. dos Santos,Renata F. Soares,Erika M. de Carvalho,Joel Jones Junior and Flavia M. da Silva
Heterocyclic Letters , 2011, DOI: july 15, 2011.
Abstract: A new, simple and eco-friendly protocol has been developed for the preparation of trisubstituted imidazoles through the Radziszewski reaction between formaldehyde (37% aqueous solution), amines, ammonium carbonate and biacetyl. The synthesis was conductedat room temperature using water as the solvent.
A SOLVENTLESSSYNTHESIS OF 2-AMINOTHIOPHENES VIA THE GEWALD REACTION UNDER ULTRASONIC CONDITIONS A SOLVENTLESSSYNTHESIS OF 2-Aminothiophenen üBER DAS Gewald Reaktion unter ULTRASONIC BEDINGUNGEN
Bruno Dias de C. F. dos Santos, Josué S. Bello Forero, Erika M. de Carvalho, Joel Jones Junior and Flavia M. da Silva
Heterocyclic Letters , 2012, DOI: october 4, 2011.
Abstract: A simple, fast and efficient one-pot, three-component,solventlessprocedure for the synthesis of 2-aminothiophene derivatives under ultrasonic conditionswas developed. The combined advantages of sonochemistry, such as mild reaction conditions, good yield and short reaction times, enabled progress to be made on the synthesis of 2-aminothiophenes via the Gewald reaction.
Phylogenetic relationship of dengue virus type 3 isolated in Brazil and Paraguay and global evolutionary divergence dynamics
Helda L Alfonso, Alberto A Amarilla, Paula F Gon?alves, Matheus T Barros, Flavia T de Almeida, Telma R Silva, Eliana V da Silva, Marcio T Nunes, Pedro F. C Vasconcelos, Deusilene S Vieira, Weber C Batista, Maria L Bobadilla, Cynthia Vazquez, Mirian Moran, Luiz T.M Figueiredo, Victor H Aquino
Virology Journal , 2012, DOI: 10.1186/1743-422x-9-124
Abstract: The entire open reading frame (ORF) of thirteen DENV-3 isolated in Brazil (n?=?9) and Paraguay (n?=?4) were sequenced for phylogenetic analysis. DENV-3 grouped into three main genotypes (I, II and III). Several internal clades were found within each genotype that we called lineage and sub-lineage. Viruses included in this study belong to genotype III and grouped together with viruses isolated in the Americas within the lineage III. The Brazilian viruses were further segregated into two different sub-lineage, A and B, and the Paraguayan into the sub-lineage B. All three genotypes showed internal grouping. The nucleotide divergence was in average 6.7% for genotypes, 2.7% for lineages and 1.5% for sub-lineages. Phylogenetic trees constructed with any of the protein gene sequences showed the same segregation of the DENV-3 in three genotypes.Our results showed that two groups of DENV-3 genotypes III circulated in Brazil during 2002–2009, suggesting different events of introduction of the virus through different regions of the country. In Paraguay, only one group DENV-3 genotype III is circulating that is very closely related to the Brazilian viruses of sub-lineage B. Different degree of grouping can be observed for DENV-3 and each group showed a characteristic evolutionary divergence. Finally, we have observed that any protein gene sequence can be used to identify the virus genotype.
Application of Finite Elements Method for Structural Analysis in a Coffee Harvester  [PDF]
Evandro Pereira da Silva, Fábio Moreira da Silva, Ricardo Rodrigues Magalh?es
Engineering (ENG) , 2014, DOI: 10.4236/eng.2014.63017
Abstract:

Stress concentration and large displacements are usual problems in the components of the structure of agricultural machinery such harvesters coffee, and that finite element method (FEM) can be a tool to minimize its effects. The goal of this paper is to get results of stresses and displacements of a coffee harvester structure by using FEM for static simulation. The main parts of the coffee harvester analyzed were: engine frame, body right and left sides, front and rear end, main beam, coffee reservoir, wheels and fuel tank. Two different design concepts of a coffee harvester machine were analyzed (structure with rear wheels aligned and misaligned) and the results were compared. It was observed that the model with rear wheels misaligned showed maximum displacement lower than the model with rear wheels aligned. Although higher stress was found in the rear wheels misaligned, it was observed that average stresses for the misaligned wheels design were lower in most structural components analyzed. Based on FEM results, the coffee harvester machine with misaligned rear wheels was built and subjected to operational tests without showing any structural failure.

The searched freedom: last philosophical speculation of Luigi Pareyson. (1975-1991) La libertad buscada: última especulación filosófica de Luigi Pareyson (1975-1991)
íris Fátima Da Silva
HYBRIS : Revista de Filsofía , 2012,
Abstract: The presented theme is developed in the volume Ontologia della libertà. Il male e la sofferenza, in which Luigi Pareyson deeply rethink the problem of liberty, articulated through a decisive confrontation, whose ontological and hermeneutic root, puts itself in relation with the Hebrew-Christian “myth”. However, is inside the person’s experience crystallized in human existence that occurs the confrontation between philosophy and religion presented on the already alluded volume. Nevertheless, the sought for freedom is the reveling speculation of Pareyson’s effort to respond to evil and suffering experience that signs the human existence; it is, in fact, the trodden search since the first investigations about the existence philosophy as crisis philosophy, in our time, in which inserts the person’s singularity in its historical concreteness, both in fullness and variety of its manifestations El presente artículo se fundamenta en el libro Ontologia della libertà. Il male e la sofferenza en el que Luigi Pareyson replantea profundamente el problema de la libertad, articulada a través de una confrontación decisiva, cuya raíz hermenéutica y ontológica se pone en relación con el “mito” hebreo-cristiano. Será dentro de la experiencia de la persona cristalizada en la existencia humana que acontece el enfrentamiento entre filosofía y religión presentado en el ya aludido texto. Más aún, la búsqueda de la libertad es la especulación reveladora del esfuerzo de Pareyson para responder a la experiencia del mal y del sufrimiento que marcan la existencia humana; es, en realidad, la búsqueda encaminada desde las primeras investigaciones sobre la filosofía de la existencia como filosofía de la crisis, de nuestra época, en la que se inserta la singularidad de la persona en su historicidad concreta, sea en la totalidad como en la variedad de sus manifestaciones
Forma o da obra de arte. O formar como “fazer” que, enquanto faz, inventa o “modo de fazê-lo”: uma perspectiva estética em Luigi Pareyson
íris Fátima da Silva
Princípios : Revista de Filosofia , 2009,
Abstract: The purpose of the present text is to bring into light brief considerations concerning forming as “doing” that, while it does, it invents the “way of doing it”: an aesthetic perspective in Luigi Pareyson, for whom, “production is, at the same time and indivisibly, invention”. The personal interpretation is the making evident of the work itself, that is, giving, revealing, pulling the curtain of the work in itself. Interpreting is in agreement with Pareyson, in itself, always personal; however, it is just one form among many other possible ones. The plurality of interpretations should not be considered a disadvantage; far from being a “defect” it is already a revelation of the inexorability of human thought. When conceiving the interpretation as singular, it is evidenced the historicity of thinkers context and personality. We will begin with some considerations concerning aesthetics, and treat about the form as execution and the forming as experiment freewards.
Biolixivia o de metais do lodo de curtume em duas etapas: influência do pH = Bioleaching of metals from tannery sludge in two stages: effect of pH
Fábio Moreira da Silva
Acta Scientiarum : Technology , 2009,
Abstract: O presente trabalho avaliou a influência do pH final sobre a biolixivia o de Cr e outros metais do lodo de curtume, utilizando um sistema com a separa o das etapas de oxida o biológica do enxofre elementar e de lixivia o do resíduo. A concentra o de enxofre elementar foi de 5 g L-1. O pH final de biolixivia o variou de 3,0 a 1,0. A concentra o de sólidos do lodo de curtume lixiviado foi de 100 g L-1 e as temperaturas foram de 298,15 e 308,15 K. As porcentagens de extra o de Al, Cr e Zn tiveram acréscimos para menores valores de pH final, enquanto as de Ca decresceram nessas condi es. A extra o máxima de Cr foi de 70,11% em concentra o de sólidos do lodo de 100 g L-1, pH final de 1,0 e temperatura de 298,15 K. A fra o de Cr ligada aos óxidos de Fe e Mn teve maior varia o no teor do metal do que as outras fra es, pelas mudan as de pH final. Araz o em massa dos metais e do Cr decresceu para menores valores de pH final. A concentra o de Cr lixiviado do lodo de curtume, após a biolixivia o em pH final 1,0, foi reduzida a valores satisfatórios. The present work assessed the effect of the pH in the bioleaching of Cr and other metals from tannery sludge with stage separation of biologic oxidation of elemental sulfur and leaching of solid waste. The concentration of elemental sulfur was 5 g L-1. The finalbioleaching pH ranged from 3.0 to 1.0. The concentration of sludge solids was 100 g L-1 and the temperatures were 298.15 and 308.15 K. The leaching extractions of Al, Cr and Zn increased at lower final pH and the leaching extraction of Ca decreased in this condition.The maximum extraction of Cr was 70.11% at sludge solids concentration of 100 g L-1, final pH 1.0 and temperature of 298.15 K. The fraction of Cr bound to Fe and Mn oxides was more affected by changes at final pH than others fractions. The mass ratio of metals and Cr decreased at lower final pH. The concentration of Cr leached from the tannery sludge after the bioleaching at final pH of 1.0 was reduced to satisfactory values.
AS EXTERNALIDADES: Análise de um enfoque do pensamento de Ronald H. Coase
Fábio da Silva Porto
Revista Eletr?nica do Curso de Direito da UFSM , 2012, DOI: 10.5902/198136947139
Abstract: Uma reflex o sobre o fen meno jurídico do ponto de vista econ mico é uma das vertentes mais relevantes na discuss o sobre o papel do Estado na regula o das rela es privadas, especialmente aquelas destinadas à obten o da satisfa o das necessidades individuais. O trabalho do autor Ronald H. Coase mostra-se referência nessa área, apontando a autotutela do mercado como a melhor via para o atendimento dessas necessidades, inclusive para a corre o das externalidades que podem ocorrer em decorrência de algum desequilíbrio do sistema. Conhecer esse pensamento é indispensável para uma análise econ mica e crítica do Direito.
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