Ações de divulgação de química na Casa da Descoberta - centro de divulgação de ciência da Universidade Federal Fluminense

This paper describes the main activities regarding scientific dissemination in the field of Chemistry at Casa da Descoberta (CD) - a Scientific Dissemination Center of the Fluminense Federal University. It presents a brief history of CD and discusses the difficulties concerning the dissemination of Chemistry at Scientific Dissemination Centers. This work also approaches some activities developed throughout the years: experiments performed in relation to the visitors' daily life, training of monitors to act as mediators in the non-formal teaching of Chemistry, production of dissemination materials, elaboration of books, as well as activities that relate formal to non-formal education.

Investigando a presença da história da ciência em livros didáticos de Química Geral para o ensino superior

This paper aims at analyzing the history of science content of three general chemistry textbooks used in Brazilian universities: the translations of Kotz and Treichel's Chemistry & Chemical Reactivity, Atkins and Jones's Chemical Principles, and Garritz and Chamizo's Química. Results revealed different trends for the inclusion of history of science in chemistry teaching. Kotz & Treichel and Atkins & Jones used history mainly as curiosity and ornament. Garritz & Chamizo adopted the historical approach as one of the organizing axis of their textbook. Nevertheless, the historical content of the three textbooks may be criticized from current historiographical standpoint.

Espectroscopia no infravermelho médio e análise sensorial aplicada à detecção de adulteração de café torrado por adição de cascas de café

Mid-infrared spectroscopy and chemometrics were used to identify adulteration in roasted and ground coffee by addition of coffee husks. Consumers' sensory perception of the adulteration was evaluated by a triangular test of the coffee beverages. Samples containing above 0.5% of coffee husks from pure coffees were discriminated by principal component analysis of the infrared spectra. A partial least-squares regression estimated the husk content in samples and presented a root-mean-square error for prediction of 2.0%. The triangular test indicated that were than 10% of coffee husks are required to cause alterations in consumer perception about adulterated beverages.

Química Nova Interativa - QNInt - o portal do conhecimento da SBQ: conectando ciência e educação

The Química Nova Interativa (QNInt) portal was launched in 2009 by the Brazilian Chemical Society (SBQ) to offer free quality content for broad audiences. QNInt provides peer-reviewed articles from SBQ journals on science & society, chemical concepts, classroom activities and educational research. With 3,000,000 visits, QNInt also offers a unique library of interactive molecules. In the International Year of Chemistry QNInt served for distributing pH kits and registering data from IUPAC's Global Water Experiment, yielding Brazil the largest share of the global pH data set. The portal performance makes QNInt a valuable resource for connecting science to education.

Síntese de cristais líquidos derivados do nitroazobenzeno: uma proposta de síntese multi-etapas aplicada às aulas de química orgânica experimental

We describe a synthetic route consisting of five steps from aniline to obtain liquid crystal compounds derived from nitroazobenzene. Syntheses were performed during the second half of the semester in organic chemistry laboratory classes. Students characterized the liquid crystal phase by the standard melting point techniques, differential scanning calorimetry and polarized optical microscopy. These experiments allow undergraduate students to explore fundamentally important reactions in Organic Chemistry, as well as modern concepts in Chemistry such as self-assembly and self-organization, nanostructured materials and molecular electronics.

Química de productos naturales aplicada a la acuicultura: una revisión interdisciplinar

This review sought to highlight the importance of natural products versus synthetic products, as bioactive molecules, towards the development of better management practices in aquaculture. The nature, structure, activity, and applications of these naturally-occurring high value-added compounds are described, as well as the methodology used for their study. Examples include the well-known rotenone, eugenol, forskolin, isatin, malyngamide, chlorodesmine, pachydictyol, fimbrolide, and other potentially active molecules in aquaculture.

Análise exploratória aplicada a espectros de reflexão total atenuada no infravermelho com transformada de Fourier (ATR-FTIR) de blendas de biodiesel/diesel

In this study, hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to classify blends produced from diesel S500 and different kinds of biodiesel produced by the TDSP methodology. The different kinds of biodiesel studied in this work were produced from three raw materials: soybean oil, waste cooking oil and hydrogenated vegetable oil. Methylic and ethylic routes were employed for the production of biodiesel. HCA and PCA were performed on the data from attenuated total reflectance Fourier transform infrared spectroscopy, showing the separation of the blends into groups according to biodiesel content present in the blends and to the kind of biodiesel used to form the mixtures.

EFEITO DO DIOXIDO DE CARBONO SOBRE A ESTABILIDADE DA FASE Ca2Fe2O5 APLICADA NO PROCESSO DE DEGRADAÇÃO FOTOCATALITICO DO AZUL DE METILENO

Solid samples containing a Ca2Fe2O5 phase were synthesized using the Pechini method. The samples were characterized using X-ray diffraction, thermogravimetric analysis, differential thermal analysis, X-ray fluorescence, nitrogen adsorption/desorption isotherms, and scanning electron microscopy. The stability of the Ca2Fe2O5 phase was evaluated in the photocatalytic degradation of methylene blue (MB) in aqueous solution in the presence of bubbling gas (air, N2, or CO2). The presence of CO2 is known to suppress MB degradation. After the photocatalytic test, changes were observed in the crystalline phase of all systems. These results suggest the low stability of the Ca2Fe2O5 phase in aqueous systems and the significant effect of CO2 on the photocatalytic activity of the Ca2Fe2O5 phase.

A ciência nas utopias de Campanella, Bacon, Comenius, e Glanvill

Este artigo analisa comparativamente o papel que a ciência e a técnica ocupam nas sociedades descritas em A cidade do Sol de Tommasio Campanella, a Nova Atlântida de Francis Bacon, Panorthosia de Jan Amós Comenius e o Complemento à Nova Atlântida de Joseph Glanvill.

Ética, ciência e tecnologia

O artigo visa pensar a relação entre ética, ciência e tecnologia, enfatizando o problema de sua revinculação depois da cisão entre os juízos de fato e os juízos de valor, ocorrida no início dos tempos modernos. Uma vez examinada a ética da aristocracia guerreira e a moral do santo, procura-se delinear o caminho tomando como referência a ética da responsabilidade, cujo protótipo é a moral do sábio, desaparecido no curso dos tempos modernos, em razão da fragmentação do saber e do advento do especialista. Ao fim do estudo, é discutida a relação entre a ética e a metafísica, com o intuito de ajustar a questão antropológica à perspectiva cosmológica, bem como de fornecer as bases de um novo humanismo, objetivando a humanização da técnica e a geração de um novo homem, alfabetizado em ciência, tecnologia e humanidades.

O trágico, o cômico e a "distância artística": arte e conhecimento n'A Gaia Ciência, de Nietzsche

A partir da leitura de A Gaia Ciência, pretendemos mostrar alguns elementos importantes que, nesse livro, se constituem em torno do tema da "distância". Analisando principalmente três aforismos do livro, procura-se esclarecer o deslocamento no texto e no pensamento de Nietzsche da distância como Ferne, de origem romântica, à distância como Distanz. Entretanto, procura-se ao final mostrar que Nietzsche desloca o tema romântico da Ferne, caracterizando-a como uma "distância artística", que se torna o traço distintivo entre a perspectiva da arte e a perspectiva do conhecimento.

Hegel leitor de deleuze: uma perspectiva crítica da ontologia afirmativa a partir das objeções a spinoza na ciência da lógica

Este artículo se propone realizar un abordaje crítico de la ontología afirmativa de Gilles Deleuze a partir de las objeciones realizadas por Georg Hegel a Spinoza en su Ciencia de la lógica. La hipótesis de trabajo es que, dada la herencia spinozista del pensamiento de Deleuze, estas críticas pueden resultar pertinentes para reflexionar sobre algunos puntos fundamentales. De esta manera, se intenta contrariar la habitual tendencia de los estudios deleuzianos de trabajar en una clave anti-hegeliana, es decir, a partir de una separación teórica total con la problemática de Hegel. Se descarta la posibilidad de centrar las críticas de Hegel en torno a la sentencia "omni determinatio est negatio" o la imposibilidad de progresar desde la afirmación absoluta (por lo que el verdadero comienzo en Spinoza -y por tanto en Deleuze- sería la mera realidad empírica donde los elementos se vinculan de manera extrínseca, es decir, sin concepto). El punto de inconmensurabilidad es que Hegel afirma que es necesario que exista un movimiento de retorno (zurürckkehren) para que la afirmación no se degrade al punto de la disolución, mientras que Deleuze prefiere el movimiento de eterno retorno (ewige wiederkunft) como apertura insistente en el porvenir.