Isotopic Effect
Mostrando 1-12 de 92 artigos, teses e dissertações.
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1. THERMAL DECOMPOSITION REACTION IN ETHANOL SOLUTION OF DEUTERATED ACETONE CYCLIC DIPEROXIDE AND ACETONE DIPEROXIDE. SECONDARY INVERSE ISOTOPIC EFFECT
The characterization by mass spectrometry and the kinetic study of the thermal decomposition reaction of deuterated acetone diperoxide (dACDP) was studied in ethanol in the 140-165 ºC temperature range. The comparison with the non deuterated species (ACDP) was also made. The kinetic behavior observed for both compounds follows a pseudo first order kinetic l
Quím. Nova. Publicado em: 2017-05
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2. Estudo do efeito isotópico sobre a solubilidade da 3- metilpiridina em H2O e D2O / The isotopic effect on organic molecules solubility in H2O and D2O
Experimental studies of 3-methylpiridyne/water and 3- methylpiridyne/heavy water binary mixtures show solubility differences. In this work Molecular Dynamics method was used to simulate 54 model systems. Each system corresponds to a point at a temperature vs molar fractions phase diagram. The systems were simulated in cubic boxes containing a mixture of 3- m
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/12/2012
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3. Efeito de enxofre elementar na eficiência de fosfatos naturais / Effect of elemental sulfur on the efficiency of phosphate rocks
É amplamente conhecida a importância do fósforo (P) para a obtenção de boa produtividade de culturas. Sabe-se, também, que a matéria prima para produção de adubos fosfatados é um recurso escasso e não renovável. Utilizações adequadas e alternativas que busquem melhorias da eficiência das fontes de P são de grande importância para o manejo da
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/06/2012
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4. Ecologia alimentar da toninha Pontoporia blainvillei (Cetacea) / Feeding ecology of franciscana dolphin Pontoporia blainvillei (Cetacea)
Ecological niche theory is originally based on the assumption that individuals of a species use similar resources and therefore are ecologically equivalents. Under this framework, the niche of the species can be defined in terms of average resource use. However, factors such as quality and quantity of prey resources in the environment, consumer gender, age o
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/12/2011
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5. DEPLOYMENT OF METHOD FOR ANALYSIS OF STABLE CARBON ISOTOPES (N-ALKANES C1-C5) IN GAS SAMPLES AT LOW CONCENTRATIONS / IMPLANTAÇÃO DE MÉTODO PARA ANÁLISE DE ISÓTOPOS ESTÁVEIS DE CARBONO (N-ALCANOS C1-C5) EM GASES A BAIXAS CONCENTRAÇÕES
The concentration and isotopic composition of n-alkanes C1-C5 has revealed as a powerful tool for interpretation of interesting processes in the oil exploration industry, studies of global climate change, oil biodegradation and carbon cycle elucidation. In this context, studies about methane analysis have been distinguished and multiplied due to the importan
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/10/2011
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6. Isotopic composition of soils and plants in a gallery forest of cerrado biome: effect of topographic gradient.
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Planaltina. Publicado em: 2011
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7. Papel da alça microbiana na dinâmica trófica de um lago de várzea na Amazônia Central
During the hydrologic year of 2007-2008, the lago Catalão, a floodplain lake which is influenced by two of the worlds largest rivers (Solimões and Negro), was studied in terms of the dynamic of water column and the trophic dynamic of the microbial food web. At the beginning of the flood the lago Catalão is influenced by the rio Negro and at the end of thi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/03/2010
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8. Avaliação do efeito de tratamentos superficiais na resistência à corrosão de magnetos de Nd-Fe-B / Assessment of the effect of surface treatments on the corrosion resistance of Nd-Fe-B Magnets.
Nd-Fe-B magnets produced by powder metallurgy are highly susceptible to corrosion due to their complex microstructure and intrinsic porosity due to their fabrication process. Moreover, these magnets have excellent magnetic properties and find many applications. In the nuclear area, permanent magnets based on rare earth transition-iron-boron (Ne-Fe-B) are use
Publicado em: 2009
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9. Processos metalogenéticos em ambientes de arco magmático tipo andino, caso de estudo: mineralizações da região dos Andes Patagônicos setentrionais do Chile / Metallogenic processes in andean volcanic arc setting, study case: mineralizations in the Chilean North-Patagonion Andes
In the Patagonian Andes region between 41 and 44° S extensive and continuous plutonic rocks of the North-Patagonian Batholith north segment are exposed. During their evolution most of the granitic rocks were emplaced in metamorphic rocks and other parts were emplaced in Late Jurassic-Berriasan volcanic rocks, Early Cretaceous sedimentary and volcanic rocks,
Publicado em: 2008
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10. Adubação nitrogenada com uréia e adubos verdes na cultura do arroz e efeito residual no feijoeiro / Nitrogen fertilization with urea and green manures in rice crops and its residual effect in bean crop
The association of green manures and mineral N sources is becoming a promising option for nitrogen fertilizer management, with the objective of recovering the soil fertility, increase of soil organic matter, reduce the loss of mineral N from the readily available sources, and in the case of legume incorporate biologically fixed N to the soil. The objectives
Publicado em: 2008
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11. Transferência do carbono de resíduos da colheita de eucalipto para frações da matéria orgânica do solo / Carbon transference from eucalypt harvest residues to soil organic matter fractions
Eucalypt plantation areas in Brazil have increased continuously over the years. The practice of removing more lignified material, such as bark and branches, from the ground after wood harvesting in eucalypt forests may prevent the stabilization of carbon (C) in recalcitrant fractions of soil organic matter (SOM). The recalcitrance of such organic fractions i
Publicado em: 2008
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12. Efeito do superfosfato triplo (32P) na absorção do fósforo do fosfato natural pelas plantas de milho e soja / Effect of triple superphosphate (32P) on phosphate rock phosphorus uptake by maize and soybean plants
The efficiency of phosphate rock (PR) can be improved applying it together with watersoluble P fertilizer. Four experiments were carried out in the greenhouse of the Soil Fertility Laboratory, CENA/USP (Centro de Energia Nuclear na Agricultura - Universidade de São Paulo), with maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] grown in a dystrophic T
Publicado em: 2007