Chemistry Composition
Mostrando 13-24 de 138 artigos, teses e dissertações.
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13. UM ESTUDO TERMODINÂMICO DA CORROSÃO DOS AÇOS CARBONO PELO SULFETO DE HIDROGÊNIO - EXPLORANDO CONCEITOS DE EQUILÍBRIO QUÍMICO
This study addresses an inherent problem to the oil and natural gas exploration and production industry, the corrosion of pipes and tanks by H2S. H2S with water emulsified in the oil or H2S with the water vapor mixed in the gas, they make the acid environment leading to corrosion. This is commonly manifested by the formation of insoluble sulfides on the surf
Quím. Nova. Publicado em: 2018-05
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14. Fragmentation Reactions of Rhodamine B and 6G as Revealed by High Accuracy Orbitrap Tandem Mass Spectrometry
Correct interpretation of mass spectra is essential to our understanding of the ion chemistry occurring in the gas phase inside mass spectrometers and for constructing a solid knowledge from which mass spectrometry (MS) data of novel molecules will be interpreted. Assignments of product ions leading to incorrect dissociation mechanisms can also be dangerous
J. Braz. Chem. Soc.. Publicado em: 2017-01
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15. MATERIAIS VÍTREOS E LUZ: PARTE 1
2015 is the Year of Light, according to UNESCO. Chemistry has a close relationship with light and one of the materials that allows such synergy is glass. Depending on the chemical composition of the glass, it is possible to achieve technological applications for the whole range of wavelengths extending from the region of the microwave to gamma rays. This div
Quím. Nova. Publicado em: 2016-04
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16. MICROEMULSÕES: COMPONENTES, CARACTERÍSTICAS, POTENCIALIDADES EM QUÍMICA DE ALIMENTOS E OUTRAS APLICAÇÕES
Microemulsions (MEs) are thermodynamically stable systems consisting of nanosized droplets dispersed in a solvent continuous medium (known as pseudo-phase), which is immiscible with the dispersed phase. These systems consist of water, a hydrophobic solvent called "oil," an amphiphile and often, a co-surfactant that is normally a medium chain alcohol. A large
Quím. Nova. Publicado em: 2015-11
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17. Exploratory Analysis of the Distribution of Lignin and Cellulose in Woods by Raman Imaging and Chemometrics
The determinations of cellulose and lignin are important in wood analysis from both perspectives: chemistry composition, commercial and industrial application of woods. In this context, Raman image spectroscopy was applied in the determination of cellulose and lignin distribution in wood surfaces of Swietenia macrophylla King (Mahogany) and Eucalyptus hybrid
J. Braz. Chem. Soc.. Publicado em: 2015-06
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18. Centesimal composition and physical-chemistry analysis of the edible mushroom Lentinus strigosus occurring in the Brazilian Amazon
Avaliou-se a composição centesimal e análise físico-química do Lentinus strigosus, um cogumelo comestível de ocorrência na Amazônia brasileira, produzidos em substratos alternativos à base de resíduos madeireiros e agroindustriais. Com este objetivo, determinou-se C, N, pH, sólidos solúveis, atividade de água, proteína, lipídios, fibra total,
An. Acad. Bras. Ciênc.. Publicado em: 11/10/2013
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19. A importância da lei de Gay-Lussac para a classificação dos compostos orgânicos
This article shows the genesis of the law of volumes of combining gases, formulated by Gay-Lussac in 1808, and how it allowed the expression of the composition of organic compounds in terms of whole numbers of volumes, thus leading to the first classification of organic compounds, formulated by Dumas and Boullay in 1828. It was from this work that Organic Ch
Quím. Nova. Publicado em: 2013
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20. Aspectos da biogeoquímica dos rios Teles Pires e Cristalino - MT / Aspects of the biogeochemistry of Teles Pires and Cristalino rivers - MT
The Amazon basin occupies around 40% of the brazilian territory and contains more than 60% of the water resources of the country. Abundant and yet little exploited region water resources constitute a national treasure to which the nation can not turn its back. Besides changes in land use/cover, several hydroelectrical plants are planned for rivers in the reg
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/06/2012
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21. Efeitos dos parâmetros da extração e avaliação da qualidade física e química dos óleos de baru e amendoim / Effects of parameter extraction and quality assessment ofphysics and chemistry of baru and peanut oil
This work aimed to optimize the extraction of baru oil (Dipteryx alata Vog.) by continuous mechanical pressing and assess its quality compared to peanut oil extracted under the same conditions, since both have similar characteristics. The characterization of fruit and baru almonds from southern state of Goiás was carried out, determining their chemical comp
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/02/2012
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22. Chemistry and tensile properties of a recycled AA7050 via spray forming and ECAP/E
The aim of this work is to evaluate the conjugation of advanced processing techniques, such as spray forming, extrusion and ECAP as a processing route for reuse of machining chips generated during aircrafts manufacturing parts from AA7050-T7451 raw material plates supplied according to AMS 4050H¹. In this way, the sprayforming process was used for remelting
Mat. Res.. Publicado em: 09/08/2012
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23. Condensação de Knoevenagel de aldeídos aromáticos com o ácido de Meldrum em água: uma aula experimental de Química Orgânica Verde
This work describes an undergraduate experiment for the synthesis of Knoevenagel adduct of Meldrum's acid with nine aromatic aldehydes, using water as the solvent, in an adaptation of a previously reported synthetic protocol. The synthesis was straightforward, requiring a period of two hours, and is suitable for undergraduate experimental courses on green ch
Química Nova. Publicado em: 2012
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24. Do compromisso à responsabilidade lúdica: ludismo no ensino de Química na formação básica e profissionalizante / Commitment to responsibility playful, playfulness in teaching Chemistry in basic training and professional
This work can appears like a proposal for reflections in education by chemistry in basic training, the use of playful activities as teaching resource and student engagement in the chemistry study. It can to promote a development of the play culture in the school and from school. The teacher can propose partnership and involvement of students to develop of au
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/06/2011