Population growth and the development of cities requires large energy needs, however, it comes from fossil fuels such as oil, however, its use has unfavorable consequences to society related to its polluting effect. One way to slow down such damages is to use less polluting fuels, such as biofuels. Biodiesel is used as a suitable substitute for conventional diesel, since it is a renewable fuel obtained through the process of transesterification from raw materials such as vegetable oils, animal fats, used cooking oils, and also because Brazil presents only suitable for cultivating oilseed varieties. In order for biodiesel production to occur efficiently, the transesterification and esterification reactions require the presence of a catalyst. Basic homogeneous catalysis is the most used form of biodiesel production, but requires refined and water-free raw material. In addition, the commonly used catalysts (NaOH, KOH, etc.) are environmentally aggressive and require a neutralization step. Heterogeneous catalysts have been shown to be efficient in transesterification reactions, as they are reusable and do not require a neutralization step after the reaction. With this purpose, the objective of this work was to study the application of heterogeneous catalysts obtained from natural sources (dolomite, crab shell, eggshell and fish scales). They have some advantages such as abundance, low cost, porous structure and non-toxic. The heterogeneous catalysts studied are promising and viable in the transesterification reaction for biodiesel production.
RESUMO:O objetivo deste trabalho foi realizar a caracterização físico-química do pó e da tintura, e análise por espectrofotometria e cromatografia do extrato seco de Peperomia pellucida L. (H. B. K.). As metodologias seguiram a Farmacopéia Brasileira IV ed., com exceção da prospecção química, da espectrofotometria, da obtenção do perfil cromatográfico do extrato seco, e determinação do resíduo seco. A prospecção química revelou a presença de saponinas espumídicas; açúcares redutores; proteínas e aminoácidos; fenóis; taninos; flavonóides; esteróides e triterpenóides. Na análise por CCD, o melhor perfil da fração flavonoídica foi obtido com MeOH/CHOOH (90:10). Foi confirmada, através de CLAE, a presença de 3',4',7-tri-Ometoxiflavona no extrato seco deste material vegetal. Os resultados obtidos contribuem para a determinação de especificações de uma futura monografia em Farmacopéias da Peperomia pellucida L. (H.B.K.). Palavras-chave:Peperomia pellucida, caracterização, cromatografia líquida de alta eficiência, espectrofotometria, cromatografia em camada delgada. ABSTRACT: Physical chemical characterization and spectrophotometric analysis and chromatography (TLC) of the Peperomia pellucida L. (H. B. K.).The aim of this study was the physical chemical characterization of the powder and the tincture, and the chromatographic and spectrophotometric analysis of the Peperomiapellucida L. (H. B. K.) dry extract. The methodology followed the Farmacopeia Brasileira IV ed., except for the chemical prospection, the chromatographic profile obtained and the spectrophotometry of the dry extract, and determination of dried residues. The chemical prospection revealed the presence of foaming saponins; reducing sugars; proteins and amino acids; phenols; tannins; flavonoids; steroids and triterpenoids; depsideos and depsidones. The best profile from TLC for flavonoidic fraction was obtained with methanol/formic acid (90:10 v/v). HPLC confirmed the presence of 3 ',4',7-tri-methoxyflavone in the dry extract of the plant material. The results obtained in this work should contribute for the determination of specifications for a future monograph on Peperomia pellucida L. (H.B.K.)
Euterpe oleracea Mart. known as acai, it is a palm of bacaceous fruit, distributed throughout Brazil in states such as Amazonas, Pará, Maranhão, Rondônia and Tocantins. The objective of this work was to produce an acid-base indicator strip from the hydroalcoholic extract of the pulp of Euterpe oleracea Mart. to determine acidity by colorimetric method, also seeking to develop in a simple, fast and low cost, being an alternative way to be used in teaching Chemistry in experimental practical classes with the subject covered in Inorganic Functions in Teaching: Elementary, Middle and Higher. The methodology used was carried out in stages: (i) obtaining the acai pulp from the fruits of the açaizeiro, (ii) obtaining the extract from the pulp of Euterpe oleracea Mart., (iii) building a pH scale (0- 14), (iv) obtaining a pH paper from the hydroalcoholic extract, (v) identification of acidic and basic substances in everyday use with both the extract and the pH indicator paper, (vi) determining the acetic acid content in commercial vinegars, and (vii) a comparison of the results obtained from% acetic acid, both with the synthetic indicator (phenolphthalein) and with the natural indicator. Through the tests with the tape and with the pulp extract of Euterpe oleracea Mart. satisfactory results were obtained. Thus, the pH tape and the Euterpe oleracea Mart. pulp extract identified the acidic, basic and neutral substances of everyday life, showing an alternative for teaching with practical experimental chemistry classes, being financially viable, and exploring an application of Euterpe oleracea Mart. pulp. as forest treasure for future industrial applications, such as the production of a pH indicator strip.
O crescimento urbano desordenado iniciou-se na segunda metade do século 20, em meados desse século o Brasil tornou-se um país urbano, ou seja, mais de 50% de sua população passou a residir nas cidades. É neste contexto que ocorre o processo de expansão urbana de Breves-PA, em que ao longo dos anos houve maior aglomeração populacional, nas zonas periféricas, como é o caso da área entorno ao igarapé Santa Cruz, acarretando em cenários de problemas ambientais de várias ordens. Diante destes cenários, o presente estudo teve como objetivo identificar a situação ambiental do igarapé Santa Cruz, bem como realizar um breve estudo sobre a percepção dos residentes quanto ao meio ambiente, à captação e utilização da água do igarapé.
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