Magnetic Impurities
Mostrando 1-12 de 30 artigos, teses e dissertações.
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1. Synthesis and Evaluation of Antibacterial Activity of 1,2,3-Triazole and Ether Derivatives of Paeonol
Multi-drug-resistant bacteria (MDR) are the cause of different infections and diseases that have affected humanity for a long time, and have been an emerging global health problem that has led to increased morbidity and mortality. The growing emergence of MDR bacteria has underlined the need for development and discovery of new antibacterial compounds. In th
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Characterization and in silico Mutagenic Assessment of a New Betahistine Degradation Impurity
Currently, the pharmaceutical industry devotes great attention to drug degradation products because these compounds can offer risks to patients. A previous degradation study of betahistine (N-α-methyl-2-pyridylethylamine) conducted under different stress conditions detected three main impurities named A, B and C. Degradation products were analyzed by high-r
J. Braz. Chem. Soc.. Publicado em: 04/07/2019
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3. Synthetic Aluminosilicates for Geopolymer Production
Abstract The use of geopolymer has been studied as a potential substitute for Portland cement due to lower CO2 emission and improvements on structural properties. Some of the major raw materials used in the manufacture of the geopolymer are: steel slag, fly ash and metakaolinite. Due to the impurities contained in these raw materials, the present study uses
Mat. Res.. Publicado em: 24/01/2019
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4. Preparative Separation and Structural Identification of Impurities of a New α2-Adrenoceptor Agonist Using Stacking Injection, LC-MSn and LC-SPE-NMR
Identifying impurities in drug substances has become one of the most important issues in pharmaceutical analysis since it can have a significant impact on the efficacy of new pharmaceutical products. Due to the purity requirements, in this paper a new synthetic α2-adrenoceptor agonist, called LPSF-PT-31, was purified and its impurities were characterized by
J. Braz. Chem. Soc.. Publicado em: 2017-06
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5. Electronic Effect of V, Ti, and Sc Impurities on the Hyperfine Interactions of Fe Atoms in α-Fe: A First Principles Study
The Linearized Augmented Plane Wave method, as implemented in the Wien2k computational code, was used to investigate the effects of the 3d transition metals (TM) Sc, Ti, and V impurities on the hyperfine interaction of iron atoms in α-Fe. The calculation results of this study suggest that the introduction of a TM (TM = Sc, Ti, and V) impurity into α-Fe inc
Mat. Res.. Publicado em: 02/03/2017
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6. Determination of Aldrin Purity Using a Combination of the Mass Balance Approach and Quantitative NMR
This paper describes the studies performed to determine the purity of aldrin samples, an organochlorine pesticide, using the mass balance approach. The organic impurities were identified and quantified by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detection (GC-FID) and gas chromatography with electron capture dete
J. Braz. Chem. Soc.. Publicado em: 2015-05
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7. Propriedades físicas do SnO2: defeitos, impurezas, ligas e superredes. / Physical properties of SnO2: defects, impurities, alloys and superlattices.
O dioxido de estanho na estrutura rutila (SnO2) é um semicondutor de gap largo e faz parte da classe dos óxidos condutores transparentes (TCO). Possui gap direto de 3,6 eV e condutividade do tipo n, mesmo quando não dopado intencionalmente. Estudos teóricos e experimentais atribuem este comportamento à presença de defeitos intrínsecos. Por outro lado,
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/08/2011
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8. Transporte elétrico e magnetotransporte em carbono granular
In this work we have studied the electrical conduction between localized states in samples with dierent volumetric densities of carbon-black, a kind of granular carbon. Firstly, we have shown that the Mott s variable range hopping (VRH) model t our data in a large range of temperatures. At low temperatures, we can see a deviation to a larger exponent, which
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/05/2011
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9. Local magnetic moments and hyperfine fields at Ta impurities diluted in XFe2 (X = Y, Gd, Yb) Laves phases compounds
Neste trabalho, estudamos, à temperatura finita, a sistemática na formação dos momentos locais de uma impureza de Ta diluída em compostos intermetálicos de fases de Laves XFe2 (X = Y, Gd, Yb). Utilizamos um hamiltoniano de Hubbard, extendido à duas sub-redes acopladas, para descrever as matrizes de fases de Laves. A interação eletrônica d-d é trat
Journal of the Brazilian Chemical Society. Publicado em: 2008
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10. New functionals for the anisotropic Heisenberg model / Novos funcionais para o modelo de Heisenberg anisotrópico
The Heisenberg Model is generally recognized in the study of electromagnetism with origin in localized magnetic moments. Similar to the well known classical Ising model, it incorporates, however, quantum flutuations. We are interested in antiferromagnetic systems described by the Heisenberg Hamiltonian with exchange anisotropy and, eventually, non-null magne
Publicado em: 2008
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11. ESTUDO DO PARÂMETRO DE ORDEM E DO MOMENTO MAGNÉTICO EM BOROCARBETOS PSEUDOQUATERNÁRIOS / STUDY OF ORDER PARAMETER AND MAGNETIC MOMENT IN PSEUDOQUATERNARY BOROCARBIDES
Experimental data show that the dissolved impurities of the Mn presents a magnetic moment when substitute the Ni atom in pseudoquaternary borocarbide Y (Ni(1−x)Mx)2B2C, this is not observed if the impurities are Fe and Co. In this work we do a theoretical study of the superconducting order parameter variation and a possible formation of impurities magn
Publicado em: 2007
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12. A first-principles study of Cr impurities in iron
The first-principles molecular cluster discrete variational method (DV) is used to investigate the electronic structure and local magnetic properties of Cr impurities in bcc iron and Fe/Cr interfaces. The spin polarized case is considered within the framework of the local-spin-density approximation of the density function theory. The effect on the local mome
Brazilian Journal of Physics. Publicado em: 2006-12