The adventitious bud development was induced in epicotyl segments of Valencia sweet orange (Citrus sinensis L. Osbeck). Seeds were cultured in vitro for three weeks in the dark, followed by one week at a 16-h photoperiod. Epicotyl segments were cultured horizontally for the induction of organogenesis in Murashige and Tucker (1969, MT) culture medium supplemented with 1.0 mg dm -3 benzylaminopurine. Samples were observed by light and scanning electron microscopy from day zero to day 25, when buds were well grown. It was shown that the adventitious buds originated directly from the cambial region on the cut ends of the explants.

Este estudo busca levantar dados acerca de quarenta e sete usinas situadas na região norte do Brasil, especificamente nos estados do Amazonas e Roraima, a fim de se obter uma visão holística e técnica das usinas termoelétricas quanto a qualidade dos combustíveis adquiridos. A coordenação do setor da qualidade desenvolve um programa de visitas anuais com rotas traçadas pela geografia local, assim, as rotas são cumpridas pelos profissionais analistas químicos. Dessa forma, a fim de centrar as demandas das UTE’s em preceitos legais, este estudo determinou pontos focais nas normas que se referem à qualidade dos produtos, são elas: ANP 09 de 2007, ANP 44 de 2013 e ABNT NBR 17505, tendo como auxiliar teórico a Norma Regulamentadora 20 e a Instrução Técnica 25/19 do corpo de bombeiros do estado de São Paulo. Evidentemente, conforme se apresentam os dados, há a necessidade de orientação profissional quanto aos processos e projetos das usinas, pois há base teórica suficiente e disponível, todavia, não cumprida em sua plenitude.

This study sought to assess the panorama of the biodiesel issue in northern Brazil, referring to the physical chemical parameter of oxidative stability. Data were collected between the years 2020 and 2021 in the cities of Manaus and Porto Velho, through routine collections in the tanks of the distribution bases and analyzes carried out in the research and fuel testing laboratory (LAPEC) located at the Federal University of Amazonas (UFAM). The results showed the disparity of the oxidative stability of biodiesel with the current standard, placing it beyond the minimum specification, affecting its mixture with diesel S10, however diesel S500 still remained below the maximum limit determined by the National Petroleum Agency, Natural Gas and Biofuels (ANP). Thus, investigations carried out on the action of diesel in its mixture with biodiesel, improving its oxidative stability, determined that the sulfur content represents a significant factor for this. Therefore, this work allowed prospecting the panorama of the quality of biodiesel in the northern region of the country, directing critical thinking towards the elucidation of the exposed bottlenecks.