Electrostatic Model
Mostrando 25-36 de 275 artigos, teses e dissertações.
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25. CASCA DE ARROZ COMO ADSORVENTE PARA ÍONS DE METAIS PESADOS: Caracterização e modificação química / RICE HUSK AS ADSORBENTS FOR HEAVY METAL IONS: characterization and chemical modification
Adsorption of some metal ions (Co2+, Ni2+, Cu2+ e Zn2+) from aqueous solutions (pH 5.0) onto in nature rice husk (0.088 < <0.177 mm) was investigated. All experiments were conducted by the batch adsorption techniques at room temperature (28 1C) and under constant stirring. The adsorption amounts were determined using atomic absorption spectr
Publicado em: 2009
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26. Simulation of dense colloids
We present in this proceeding recent large scale simulations of dense colloids. On one hand we simulate model clay consisting of nanometric aluminum oxyde spheres in water using realistic effective electrostatic interactions and Van der Waals attractions, known as DLVO potentials and a combination of molecular dynamics (MD) and stochastic rotation dynamics (
Brazilian Journal of Physics. Publicado em: 2008-03
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27. Chaotic transport in plasmas / Transporte caótico em plasmas
This work presents a study of the particle transport through the edge of a plasma cofined in a tokamak. A model, with an infinite number of drift waves superposed to an equilibrium electrostatic potential, in addition to an uniform magnetic field, is introduced, what puts the problem in the form of mappings. Two mappings are analysed, viz. the standard map a
Publicado em: 2008
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28. Caracterização eletroquímica de colóides magnéticos visando a aplicações nanotecnológicas nanobiotecnológicas
Electric Double Layered Magnetic Fluids (EDL-MF) are stable colloidal dispersions of spinel ferrite type nanoparticles in water medium. The thermodynamic stability is achieved by balancing the van der Waals and magnetic dipolar attractions with the introduction of repulsive electrostatic interactions between particles in order to avoid the agglomeration phen
Publicado em: 2008
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29. Preparo, caracterização e aplicação de compósitos Fe(0)-óxidos de ferro em processos redutivos para remediação ambiental.
The reduction of Cr(VI) in aqueous medium with Fe(0)/Fe3O4 composites was investigated in bench procedures scale, particularly focusing on the efficiency of its fundamental chemical processes. The obtained results reveal that the combination of manually ground Fe(0) and Fe3O4 renders a very active system on reducing Cr(VI). The chemical characterization of t
Publicado em: 2008
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30. Interaction of hidrophilic porphyrins and extracellular hemoglobin with biomimetic models of biological membranes / Interação de porfirinas hidrofílicas e de hemoglobina extracelular com modelos biomiméticos de membrana biológica
In the first part of this work interactions of the cationic meso tetrakis (4-N-methilpyridil) porphyrin (TMPyP) and meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS4) in the free base forms with membrane model systems (ionic micelles, mixed micelles and phospholipids vesicles) in aqueous solutions, have been investigated by optical absorption, resonance lig
Publicado em: 2008
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31. Competitive adsorption of copper and mercury ions on natural and crosslinked chitosan membranes / Adsorção competitiva dos ions cobre e mercurio em membranas de quitosana natural e reticulada
Recent investigations have described chitosan, a linear polysaccharide obtained from deacetylation of chitin, as a suitable biopolymer to remove heavy metal ions from wastewater, since the amino and hydroxyl groups present in its structure can act as chelating sites. Several methods have been used to modify natural chitosan, such as crosslinking with glutara
Publicado em: 2008
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32. Estudos estruturais de histatina-5 e seu análogo, TOAC0-histatina-5: interação com metais e sistemas biomiméticos / Structural studies of Histatin-5 and its analogue, TOAC0-Histatin-5: interaction with metals and biomimetic systems
The mechanism of action of histatin-5 (Hst-5), an antifungal antimicrobial peptide from human saliva is not completely clarified. Circular dichroism (CD), fluorescence, and electron paramagnetic resonance (EPR) were used to examine the conformational behavior of Hst-5 and its analogue containing the paramagnetic amino acid TOAC at the N-terminus (TOAC0-Hst-5
Publicado em: 2008
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33. Adsorção de íons cobre(II) pela quitosana usando coluna em sistema sob fluxo hidrodinâmico
The adsorption of Cu(II) ions from aqueous solution by chitosan using a column in a closed hydrodynamic flow system is described. The adsorption capacities as a function of contact time of copper(II) ions and chitosan were determined by varying the ionic strength, temperature and the flow of the metal solution. The Langmuir model reproduced the adsorption is
Química Nova. Publicado em: 2007-08
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34. Análise por modelagem e dinâmica molecular da interação entre a integrina α6β1 e a laminina 111 humana / Molecular modelling and dynamics analisys of human α6β1 integrin and laminin 111 interaction
The extracelullar matrix (ECM) is formed by an assembly of proteins and glycoproteins which surrounds the cells, in various tissues. The laminin is a glycoprotein localized in the ECM that consists of three polypeptidic chains cross- shaped. It functions by anchoring epithelial cells to basal lamin, through associations with integrins, collagen, elastin and
Publicado em: 2007
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35. Estudo do mecanismo eletroforético de coleta na filtração de aerossóis.
Previous works have shown that the presence of electrostatic forces in particles significantly affect the performance of a filter, both increasing collection efficiency and reducing pressure drop. Recently, in the Environmental Control research group of the Chemical Engineering Department of UFSCar, Rodrigues (2005) have studied the filtration of electric ch
Publicado em: 2007
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36. Estratégias para prospecção e predição de peptídeos bioativos
Chapters one and two deal with the isolation and identification of bioactive peptides from the skin secretion of Phyllomedusa hypochondrialis. The first chapter demonstrates the use of protemic techniques, mainly mass spectrometry, for the study of bradykinin related peptides (BRPs) present in the amphibians secretion and freshly dissected skin fragments. Ei
Publicado em: 2007