01.1 - Graduação (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/2
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Item Avaliação das concentrações dos ácidos e ésteres graxos na produção de biodiesel de óleo de soja por transesterificação alcalina(2019-02-05) Gusmão, Amanda de Sena; Souza Filho, Manoel de Farias; Silva, Benjamim Henrique de Lima e; http://lattes.cnpq.br/9229641856436016; http://lattes.cnpq.br/2399784507334824; http://lattes.cnpq.br/3454183782800995Biodiesel, a biofuel alternative to petroleum diesel, consists of a mixture of monoalkyl esters of fatty acids. The most common method of obtaining biodiesel is through the reaction of alkaline transesterification of oleaginous or animal fat with alcohols of short chains, such as methanol and ethanol. Transesterification for biodiesel production is a process involving mass transfer and chemical reaction effects. In this sense, alcohols (methanol or ethanol) and refined soybean oil were mixed in the alcohol: oil: 6: 1 molar ratio and stirred at 60 ° C with a stirrer speed of 600 rpm in order to analyze the mass transfer of the individual fatty acids from soybean oil to alcohol phase. Samples of the alcohol phase were collected at determined times, then they were transesterified using an analytical method and analyzed by gas chromatography. In the reactive process, biodiesel was produce from refined soybean oil, using the alcohols methanol and ethanol. The experiments were run under the conditions specified above, using sodium hydroxide as the catalyst at the concentration of 0.5% (w / w) relative to the oil. The evolution of alkyl esters concentrations (biodiesel) over time were obtain by gas chromatographic analysis. Comparative analysis was made of the temporal evolution and yields of the individual fatty esters. The analysis of the results showed that the fatty acids in higher concentrations in the raw material (C16:0; C18:1; C18:2) reached higher levels of mass transfer in the alcohol phase (ethanol, methanol). It was observe in the reactive systems that the esters of palmitic and linoleic acids were favored in the process, whereas those of oleic acids presented lower reactivity.Item Proposta de sequência didática sobre a função orgânica álcool com foco na prevenção do uso abusivo de bebidas alcoólicas: análise a partir de aspectos da Teoria da Atividade de Leontiev(2018-08-15) Silva, Fábio Calado de Melo; Simões Neto, José Euzébio; http://lattes.cnpq.br/3560726840212196The present work presents a Teaching Learning Sequence (TLS) for teaching the organic alcohol function with a focus on the prevention of abusive use of alcoholic beverages. The choice of the topic of alcoholism was raised by the proximity of the author to people who suffer directly or indirectly with the problem of excessive or continued use of alcohol. This teaching sequence is composed of activities that seek to contemplate the pedagogical and epistemological dimensions described by Méheut and was structured in six moments using the method 5E, proposed by Patro. The first moment was thought for the students to answer a questionnaire to survey their previous conceptions on the subject; the second moment is the presentation of a video about alcoholism and notes/ appointments on relevant points; in the third moment it was thought to occur reading the article "Alcoholism and Chemical Education"; The fourth moment corresponds to the lecture on the scientific aspects of the alcohol function; in the fifth moment it was planned to carry out in-room research on conceptual and social aspects of the use of ethanol; and, finally, at the sixth moment, the evaluation must be carried out. The activities proposed in the sequence were analyzed from some categories of Leontiev's Theory of Activity, among them: objectives, actions, subjects, system of operations and results. The analysis of the results allowed realizing that the didactic sequence has potential to reach its objectives if the operations chosen for the activity are compatible with the desired cognitive actions and necessary to assimilate the concepts associated to the intended object.