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Search Results: 1 - 10 of 50901 matches for " Dionisio Zaldivar Silva "
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Polymeric Nanohydrogels of Poly(N-Isopropylacrylamide) Combined with Others Functionalized Monomers: Synthesis and Characterization  [PDF]
Lissette Agüero Luztonó, Yuneivy Cepero Donates, Luis Guillermo Guerrero Ramirez, Addys González Palomo, Dionisio Zaldivar Silva, Issa Katime
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2014, DOI: 10.4236/jbnb.2014.51005
Abstract:

Nanohydrogels from inverse microemulsion (w/o) polymerization, at 25°C, of N-isopropylacrylamide (NIPA) and functionalized monomers are described. The functionalized monomers were: N-(pyridine-4-ylmethyl) acrylamide (NP4MAM) and tert-butyl 2-acrylamidoethyl carbamate (2AAECM). The polymeric nanohydrogel obtained was characterized by attenuated total reflectance Fourier-transformed infrared spectroscopy (ATR-FTIR) and proton nuclear magnetic resonance spectrometry (1HNMR), while their morphology and particle size was assessed by scanning electron microscopy (SEM) and dynamic light scattering. Their thermal properties were studied by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). As a preliminary measure of biocompatibility, in vitro evaluations of the nanohydrogels were carried out by cellular toxicity (colon carcinoma cells, CT

Análisis Sol/Gel de hidrogeles de Copolimeros de Poli (Metacrilato de 2- Hidroxietilo -CO- Acrilamida) obtenidos mediante Radiaciones Gamma
Manuel Rapado,Daniel Concepción,Dionisio Zaldivar,Angel Manzurt
Revista Latinoamericana de Metalurgia y Materiales , 2003,
Abstract: En el presente trabajo se reporta el proceso de formación de geles durante la irradiación gamma de soluciones acuosas de metacrilato de 2 hidroxietilo y acrilamida. El análisis sol/gel del copolímero irradiado permitió estimar importantes parámetros del proceso de irradiación como son: la dosis de gelificación y virtual, las densidades de degradación y reticulación; y los rendimientos químico radiolíticos de la degradación y reticulación, de acuerdo con la ecuación modificada de Charlesby- Rosiak. La correlación de los parámetros antes mencionados permite preparar geles con una estructura apropiada para su uso como sistemas de liberación controlada de fármacos. ABSTRACT The formation of gels during gamma irradiation of aqueous solutions of 2- hydroxyethyl methacrilate and acrylamide is reported. Sol/Gel analysis of irradiated polymer was carried out and allowed to estimate important radiation parameters as gelation dose, virtual dose, degradation and crosslinking densities, yield of crosslinking and degradation of copolymer according with a modified Charlesby-Rosiak equation. The degree of copolymer conversion as a function of the absorbed dose of irradiation is presented. These parameters can be correlated with some physical and chemical properties of polymeric network formation and this way is able to design and prepare gels with the desired structure suitable as a drug delivery system.
Análisis Sol/Gel de hidrogeles de Copolimeros de Poli (Metacrilato de 2- Hidroxietilo -CO- Acrilamida) obtenidos mediante Radiaciones Gamma
Rapado,Manuel; Concepción,Daniel; Zaldivar,Dionisio; Manzurt,Angel; Altanés,Sonia; Rosiak,Januz M.;
Revista Latinoamericana de Metalurgia y Materiales , 2003,
Abstract: abstract the formation of gels during gamma irradiation of aqueous solutions of 2- hydroxyethyl methacrilate and acrylamide is reported. sol/gel analysis of irradiated polymer was carried out and allowed to estimate important radiation parameters as gelation dose, virtual dose, degradation and crosslinking densities, yield of crosslinking and degradation of copolymer according with a modified charlesby-rosiak equation. the degree of copolymer conversion as a function of the absorbed dose of irradiation is presented. these parameters can be correlated with some physical and chemical properties of polymeric network formation and this way is able to design and prepare gels with the desired structure suitable as a drug delivery system.
Estágio de adequa o das informa es contábeis às normas internacionais de contabilidade no setor de petróleo, gás e biocombustíveis
Ricardo Biali Ribeiro,José dionisio gomes da silva
Revista de Educa??o e Pesquisa em Contabilidade , 2010,
Abstract: O presente trabalho prop s discutir a seguinte quest o: com a adequa o da legisla o societária brasileira aos padr es internacionais, qual o estágio de divulga o das informa es contábeis em empresas do setor de petróleo, gás e biocombustíveis listadas na Bovespa? Visando responder a essa inquieta o, é analisado tal estágio, avaliando as informa es contábeis divulgadas pelas empresas do setor relativas aos exercícios sociais de 2007 e 2008. Com base no comparativo, s o elencadas quais ades es foram adotadas pelas empresas à nova legisla o societária referente às informa es contábeis divulgadas. A metodologia utilizada é de natureza descritiva com abordagem indutiva cujo sítio eletr nico da Bovespa foi a fonte da pesquisa. Os principais resultado encontrados apontam que houve uma adequa o antes das Leis n.os 11.638/07 e 11.941/09 na ordem de 18% com rela o ao total das práticas. A Petrobras realizou adequa o das normas na ordem de 44%, enquanto as demais companhias representaram uma média de 15% de adequa o. Após a emiss o das referidas leis, houve adequa o na ordem de 70%. Conclui-se assim que, apesar de a lei n o esgotar o direito, as empresas precisaram de substanciais adequa es após as Leis n.os 11.638/07 e 11.941/09, para se adequarem ao processo de convergência das normas internacionais de contabilidade.
Some Deviations of Form: A Little Essay on Psychoanalysis, Art and Aesthetics  [PDF]
Gustavo Henrique Dionisio
Creative Education (CE) , 2014, DOI: 10.4236/ce.2014.519196
Abstract: This work intends to investigate the use of psychoanalytical theory within the aesthetic and critical contemporary art field. To this purpose, it focuses on two philosophers who have become significant in our time: the art critic Hal Foster and the art historian Georges Didi-Huberman. This study aims to show how far the concepts generated in psychoanalytic praxis allowed interpretations that disrupt the traditional aesthetics field. This type of analysis is possible once we abandon the paradigm of “applied psychoanalysis”, which is still current in non-clinical setting. Finally, the proposal wants to argue that the category of the amorphous may clarify certain aesthetic experiences that range from the modernity of art through postmodernity.
Difus?o do cloreto de sódio no processo de salga de queijos: modelagem matemática com o emprego do método de elementos finitos
SILVA, Rui Sérgio Ferreira;BORSATO, Dionisio;SILVA, Luiz Henry Monken;
Ciência e Tecnologia de Alimentos , 1998, DOI: 10.1590/S0101-20611998000100019
Abstract: solute (sodium chloride) transference through a three-dimensional matrix (cheese) was studied applying the finite element method (mef). the variational formulation (galerkin) of the differential problem (diffusion model) had as the theoretical basis fick?s second law. the methods for time integration were developed according to crank-nicolson (central difference), and modified euler (backward difference), which presented unconditional stability. the computational program proved to be versatile in solving sampling situations in realistic condition and can be used in complex geometry. the proposed method gave good estimation of salt gain in the cheese when using a diffusion coefficient which value can be calculated by extrapolation of experimental data. the application of numeric method (mef), with crank-nicolson scheme, in the simulation of diffusion of sodium chloride in the brining showed to be close to the values published in specialized literature.
Difus o do cloreto de sódio no processo de salga de queijos: modelagem matemática com o emprego do método de elementos finitos
SILVA Rui Sérgio Ferreira,BORSATO Dionisio,SILVA Luiz Henry Monken
Ciência e Tecnologia de Alimentos , 1998,
Abstract: A transferência de um soluto (cloreto de sódio), através de uma matriz sólida tridimensional (queijo) foi estudada aplicando-se o método de elementos finitos. A formula o variacional (Galerkin) do problema diferencial (modelo de difus o) teve como base teórica a 2a lei de Fick. Os procedimentos para integra o no tempo foram o de Crank-Nicolson e o de Euler-modificado, que foram escolhidos por apresentarem estabilidade incondicional. O programa computacional desenvolvido mostrou-se versátil para resolver situa es de amostragem em condi es mais realistas e pode ser aplicado para geometrias complexas. O modelo proposto permitiu uma boa estimativa do ganho de sal no queijo, usando um coeficiente de difus o cujo valor pode ser obtido por extrapola o de dados experimentais. A aplica o do método numérico (MEF), com o esquema de Crank-Nicolson, na simula o da difus o do cloreto de sódio na salga de queijos, mostrou boa aproxima o quando os resultados foram comparados com os valores experimentais encontrados na literatura especializada.
Field theory
Bazeia, Dionisio;
Brazilian Journal of Physics , 2004, DOI: 10.1590/S0103-97332004000700025
Abstract: we offer a summary of the talks, oral communications and posters presented at the field theory section of the xxiv brazilian national meeting on particles and fields.
Scalar fields: from domain walls to nanotubes and fulerenes
Bazeia, Dionisio;
Brazilian Journal of Physics , 2002, DOI: 10.1590/S0103-97332002000500009
Abstract: in this work we review some features of topological defects in field theory models for real scalar fields. we investigate topological defects in models involving one and two or more real scalar fields. in models involving a single field we examine two different subclasses of models, which support one or more topological defects. in models involving two or more real scalar fields, we explore the presence of defects that live inside topological defects, and junctions and networks of defects. in the case of junctions of defects we investigte structures that simulate nanotubes and fulerenes. our investigations may also be used to describe nonlinear properties of polymers, langmuir films and optical solitons in fibers.
Small steps to emerge from the tunnel
Dionisio Vianello
Techne : Journal of Technology for Architecture and Environment , 2012,
Abstract: Based on the experience and activities of the National Centre for Town Planning Studies of the National Council of Engineers (CNI), and AUDIS, the Disused Urban Areas Association, the author proposes some suggestions to emerge – with small steps – from the tunnel of the crisis. First of all, do what is necessary. Simplify the planning regulations and procedures. Measures to take in the short term and at no cost: town planning reform, taking up the Lupi-Mantini proposals previously discussed and shared in the last legislation by Commission VIII of the Chamber on the Territory and Environment; a new law on the landholding system, the proposal developed by CNA (National Confederation of Artisans and Small and Medium Enterprises), CNI, ANCE (Italian National Association of Construction Companies) and Tecnoborsa. Secondly, do what is useful: quality and innovation in urban redevelopment projects. The AUDIS Charter on urban regeneration; the Quality Protocol for Roma Capitale. Thirdly, something extra: targeted projects for start-ups. Social Housing. The city to be scrapped. The renewal of residential assets. The divestment of state-owned properties. The reuse of obsolete industrial buildings.
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