Stability Constants
Mostrando 13-24 de 151 artigos, teses e dissertações.
-
13. Phase transition and elasticity of gallium arsenide under pressure
Geometry optimization calculations were performed for some structural, elastic and mechanical properties of gallium arsenide (GaAs) under pressures up to 25 GPa. In contrast to previous works, a recent Stillinger-Weber type potential was used for the first time to elaborate the pressure dependence aspects of GaAs. B3→B1 phase transition pressure was determ
Mat. Res.. Publicado em: 15/08/2014
-
14. Equilibrium studies of 2,2'-(5-bromo-6-methylpyrimidine-2,4-diyl)bis(azanediyl)dipropanoic acid with some transition-metal ions in aqueous solution
The stability constants of the 1:1 complexes formed between M2+ (M2+: Mn2+, Ni2+, Cu2+, or Cd2+) and BMADA2- (BMADA: 2,2'-(5-bromo-6-methylpyrimidine-2,4 diyl)bis(azanediyl)dipropanoic acid) were determined by potentiometric pH titration in aqueous solution (I = 0.1 mol L-1, NaNO3, 25 °C). The stability of the binary M - BMADA complexes is determined by the
Quím. Nova. Publicado em: 2014-06
-
15. Target-directed catalytic metallodrugs
Most drugs function by binding reversibly to specific biological targets, and therapeutic effects generally require saturation of these targets. One means of decreasing required drug concentrations is incorporation of reactive metal centers that elicit irreversible modification of targets. A common approach has been the design of artificial proteases/nucleas
Braz J Med Biol Res. Publicado em: 02/07/2013
-
16. Methane combustion kinetic rate constants determination: an ill-posed inverse problem analysis
Methane combustion was studied by the Westbrook and Dryer model. This well-established simplified mechanism is very useful in combustion science, for computational effort can be notably reduced. In the inversion procedure to be studied, rate constants are obtained from [CO] concentration data. However, when inherent experimental errors in chemical concentrat
Quím. Nova. Publicado em: 2013
-
17. Implementação de um algoritmo numérico para solução da equação de Christoffel generalizada em acustoelasticidade. / Implementation of a numerical algorithm for solution of the generalized Chistoffel equation in acoustoelasticity.
Extensive studies carried out in the last decades on the propagation of ultrasonic waves in solids led to the development of nondestructive techniques for the assessment of the safety and integrity of industrial structures and components. The interest in the application of ultrasound techniques for stress measurement for example comes from the measurable cha
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 31/08/2012
-
18. Análise de especiação de cobre e zinco empregando voltametria de redissolução anódica com pulso diferencial
This work describes methodologies for speciation analysis of the metals copper and zinc as total, total dissolved, labile, as well as complexation capacity (conditional stability constants and available ligand concentration), using the same technique, differential pulse anodic stripping voltammetry (DPASV). Several supporting electrolytes were tested, and th
Química Nova. Publicado em: 2012
-
19. Estabilidade oxidativa de queijo prato adicionado de luteína / Oxidative stability of cheese prato added with lutein
Lutein is associated with the reduction and prevention of age-related macular degeneration (ARMD), the main cause of irreversible blindness in the elderly. As this carotenoid is not synthesized by the human organism, its addition in cheese Prato is an option to lutein supplementation in the diet, beyond being able to act in the prevention of photo-oxidation.
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/04/2011
-
20. DETERMINAÇÃO DAS CONSTANTES DE ESTABILIDADE DOS COMPLEXOS FORMADOS ENTRE OS AMINOÁCIDOS CISTEÍNA, N-ACETILCISTEÍNA E LISINA COM CHUMBO EM SOLUÇÃO AQUOSA / DETERMINATION OF STABILITY CONSTANTS FOR LEAD COMPLEXES WITH CYSTEINE, N-ACETYLCYSTEINE AND LYSINE IN AQUEOUS SOLUTIONS
In this study we investigated the interaction between lead and the amino acid cysteine, lysine and N-acetylcysteine by testing long-term contact with ion exchanger resins and also the determination of stability constants. The importance of investigating the presence of lead in solutions for parenteral nutrition is related to the risk of internal contaminatio
Publicado em: 2011
-
21. Constantes de acidez de ácidos dipróticos a partir de titulações potenciométricas: ilustração dos princípios do cálculo através da construção de um algoritmo muito simples
This work describes the creation of an very simple calculation algorithm, based in basic chemical and mathematic principles, for the calculation of weak diprotic acid dissociation constants as, for example, amino acids, from potentiometric titrations. For an easier understanding of the algorithm the logical reasoning of this calculus is schematized in a diag
Química Nova. Publicado em: 2011
-
22. STUDY OF BINARY COMPLEXES OF ALUMINUM(III) WITH SULFUR AMINO ACIDS AND PHOSPHATE LIGANDS / ESTUDO DE COMPLEXOS BINÁRIOS DE ALUMÍNIO(III) COM AMINOÁCIDOS SULFURADOS E LIGANTES FOSFATADOS
The study of binary complexes of Al(III) with sulfur amino acids (methionine, cysteine, homocysteine and penicillamine) and phosphate ligands (adenosine 5 - triphosphate and phosphocreatine) was done in aqueous solution applying potentiometric titrations, (13)C and (27)Al NMR, Raman spectroscopy, molecular modeling and DFT: B3LYP/6-311G theoretical calculati
Publicado em: 2010
-
23. ESTUDO FISICO-QUÍMICO DO COMPLEXO DE INCLUSÃO DO FÁRMACO TRIMETOPRIM COM A β CICLODEXTRINA ALEATORIAMENTE METILADA / STUDY OF PHYSICAL-CHEMICAL INCLUSION COMPLEX DRUG TRIMETHOPRIM WITH RANDOM METHYL Β CYCLODEXTRIN
Cyclodextrins are well-known as good solubilizers for many drug molecules, since they are capable of increasing the solubility of the drugs by the formation of inclusion complexes, which in turn can be used in pharmaceutical formulations. In this work we aimed to prepare and characterize inclusion complexes of the randomly methylated β-cyclodextrin (RAM
Publicado em: 2010
-
24. Biological sensors based on immune response cells applied to the study of anti-allergic activity of natural compounds. / Utilização de sensores biológicos baseados em células de resposta imune no estudo da atividade antialérgica de substâncias naturais.
Anti-allergic activity of extracts and isolated compounds obtained from natural sources was investigated using the mast-cell based biosensor system. Mast cells release beta-hexosaminidase enzyme which is used as a marker of degranulation. Flavonoids (quercetin-Qc and rutin-Rt) and polyphenolic acids (caffeic acid-Cf and dimethoxy cinnamic acid-Dm) were used
Publicado em: 2009