01. Universidade Federal Rural de Pernambuco - UFRPE (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/1
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Resultados da Pesquisa
Item Análise da abordagem histórica das transformações da matéria no livro de ciências utilizado em turmas de 9º ano na cidade de Araçoiaba – PE em 2023(2023-09-12) Melo, Camila da Silva; Silva, João Roberto Ratis Tenório da; http://lattes.cnpq.br/2659442558566241Considering the great importance that science textbooks have in the teaching-learning process of science content in basic education, studies and research focused on this material have increased significantly. Considering that science education is not only pedagogical, but also contributes to the formation of critical individuals capable of acting directly in society. An interesting alternative found for this proposal is the teaching of science through the history of science. Thus, this research sought to analyze the historical and epistemic approach of the content of Material Transformations in the 9th grade textbook selected by the public school system of the city of Aracoiaba - PE. The research is qualitative with documentary perspective and the analysis criteria were based on the criteria determined by the National Textbook Program 2020. The content was identified in the book, followed by the analysis and discussion of the criteria proposed in the methodology. Made the analysis it was possible to observe that the book does not meet the criteria established in this research, because it does not make a contextualized approach as the history of chemistry, besides not involving social, political, environmental or technological aspects in the presentation of the content.Item Aplicações de reações multicomponentes em química medicinal(2021-12-20) Nascimento, Lídia Maria Barbosa do; Nascimento, André Augusto Pimentel Liesen; http://lattes.cnpq.br/8040722729889752; http://lattes.cnpq.br/1374229353141799The Multicomponent Reactions (RMCs) are very important reactions in the field of organic chemistry and have been expanding over the decades. These reactions start from 3 or more components to form a single product, in a method known as one-pot, that is, in a single container. Which brings many advantages due to meet the Green Chemistry principles, for being a linear and rapid synthesis, and still collaborate for the call “atomic economy”; in addition to forming complex molecules starting from simple and accessible precursors, as a basis for the formation of intermediaries or products with biological activities, thus bringing great collaborations and applications in Medicinal Chemistry. Many reactions are based on the principle of RMCs, among the best known and widely used are the reaction of Strecker, Hantzsch, Biginelli, Mannich, Passerini and Ugi, the last two being based on isocyanides.Item Reações oscilantes e a entropia(2019-07-29) Carneiro, Mikelâne de Oliveira; Soares Neto, Luciano de Azevedo; http://lattes.cnpq.br/7676222115726194; http://lattes.cnpq.br/5531450021947295This work has as main objective to describe the oscillating reaction and its relation with entropy according to the contribution of Prigogine. Oscillating reactions for a long time were not accepted, as it was thought to violate the second law of thermodynamics, entropy, because they occur in open systems and away from chemical equilibrium, as many scientists only recognized the term entropy in isolated systems. Reversible, this idea gained notoriety because the entropic term arose from the operation of Carnot's thermal machine. With the need to explain entropy in systems of nature, giving rise to the term "irreversibility", Boltzmann brings in his analysis the behavior of gas. In this way he treats entropy in a probabilistic manner, but Boltzmann does not take into account that gas can interact, resulting in an energy balance of the system, this is only possible through the free energy of Gibbs, thus causing if the reaction is or not spontaneous. In 1950 comes the first oscillating reaction accepted by the scientific community, called Belesouv-Zhabostinsky reaction. With the difficulty of understanding the entropy in these reactions and even creating a mechanism, Ilya Prigogine in her studies develops a theory that gave her full prestige, the dissipative structures, thus giving her the Nobel Prize for such prowess, as these dissipative structures allowed the analysis of entropy in these reactions. Through Prigogine's analysis of dissipative structures we reproduce two systems of oscillations, temporal and spatial from the Belesouv-Zhabostinsky reaction system. During the reaction we reproduce, these oscillations occur due to an energy balance between entropy and Gibbs free energy. According to Prigogine this happens because in a system, open and far from equilibrium, entropy is capable of evolving in order to restructure and reorganize, surviving by dissipating the energy of the system in the local process, so that the fall that gets in your internal entropy is "paid" for the entropic dissipation of your system. Thus entropy is a structuring theme for chemistry, generating a more accurate view of its meaning and its implications.