996 resultados para Inter-polyelectrolyte-complexes


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O tema deste trabalho é a (in)disciplina em contexto de sala de aula, colocando - se o enfoque nas representações alunos do 3º ciclo, pais e professores sobre esta problemática e as suas perceções sobre o tipo de ocorrências e causas. Este estudo de caso procura um entendimento da indisciplina, reconhecendo-se a existência de uma miríade de fatores subjacentes a este conceito, cruzando diferentes olhares da psicologia, sociologia e pedagogia. O conceito de indisciplina é definido com referência ao conceito de disciplina traduzindo um comportamento disruptivo que emerge na relação pedagógica. A construção da relação interpessoal entre professor/aluno e a gestão do comportamento dos alunos assegura a manutenção de um clima que permite a efetividade do processo ensino – aprendizagem. Realiza-se uma abordagem numa perspetiva conceptual, procurando-se o conhecimento e natureza do conceito, a identificação das causas centrados no aluno desde as suas características psicológicas, sócio – económicas, de contexto familiar e culturais, as causas centradas no professor e na organização escolar, bem como as causas sociais que influenciam a ocorrência de (in)disciplina. Explanam-se formas de gestão e resolução de comportamentos disruptivos, atendendo a diferentes e possíveis abordagens. Efetua-se, numa perspetiva empírica, na tentativa de compreender o impacto da interação pedagógica na ocorrência de atos disruptivos, a análise e interpretação de dados obtidos por triangulação de métodos, a partir de uma população de alunos de 3ºciclo, professores e pais, permitindo uma reflexão e confrontação sobre as representações destes atores e as realidades observadas.

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This paper discusses a study undertaken to test various speech discrimination tests.

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The identification, tracking, and statistical analysis of tropical convective complexes using satellite imagery is explored in the context of identifying feature points suitable for tracking. The feature points are determined based on the shape of complexes using the distance transform technique. This approach has been applied to the determination feature points for tropical convective complexes identified in a time series of global cloud imagery. The feature points are used to track the complexes, and from the tracks statistical diagnostic fields are computed. This approach allows the nature and distribution of organized deep convection in the Tropics to be explored.

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Noncovalent interactions play key roles in many natural processes leading to the self-assembly of molecules with the formation of supramolecular structures. One of the most important forces responsible for self-assembly is hydrogen bonding, which also plays an important role in the self-assembly of synthetic polymers in aqueous solutions. Proton-accepting polymers can associate with proton-donating polymers via hydrogen bonding in aqueous solutions and form polymer-polymer or interpolymer complexes. There has been an increased interest among researchers in hydrogen-bonded interpolymer complexes since the first pioneering papers were published in the early 1960s. Several hundred research papers have been published on various aspects of complex formation reactions in solutions and interfaces, properties of interpolymer complexes and their potential applications. This book focuses on the latest developments in the area of interpolymer complexation via hydrogen bonding. It represents a collection of original and review articles written by recognized experts from Germany, Greece, Kazakhstan, Poland, Romania, Russia, UK, Ukraine, and the USA. It highlights many important applications of interpolymer complexes, including the stabilization of colloidal systems, pharmaceuticals, and nanomaterials.

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The formation of hydrogen-bonded interpolymer complexes between poly(acrylic acid) and poly(N-vinyl pyrrolidone) as well as amphiphilic copolymers of N-vinyl pyrrolidone with vinyl propyl ether has been studied in aqueous and organic solutions. It was demonstrated that introduction of vinyl propyl ether units into the macromolecules of the nonionic polymer enhances their ability to form complexes in aqueous solutions due to more significant contribution of hydrophobic effects. The complexation was found to be a multistage process that involves the formation of primary polycomplex particles, which further aggregate to form spherical nanoparticles. Depending on the environmental factors (pH, solvent nature), these nanoparticles may either form stable colloidal solutions or undergo further aggregation, resulting in precipitation of interpolymer complexes. In organic solvents, the intensity of complex formation increases in the following order: methanol < ethanol < isopropanol < dioxane. The multilayered coatings were developed using layer-by-layer deposition of interpolymer complexes on glass surfaces. It was demonstrated that the solvent nature affects the efficiency of coating deposition.

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Boron-containing complexes that have the potential to irreversibly accumulate in melanoma cells have been prepared by reaction of amino acids with 9-methoxy-9-borabicyclo[3.3.1]nonane. The ability of each complex to act as a substrate for tyrosinase has been probed by oximetry. Increased uptake of the lead candidate in a tyrosinase-rich cell line, compared with a tyrosinase-absent cell line, is reported, with results correlating well with that for a drug currently approved for BNCT.