Crystallographic Structure
Mostrando 1-12 de 471 artigos, teses e dissertações.
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1. Crystallographic Changes Accompanying the Verwey Transition in a Magnetite from Steatite
The crystallographic structural analysis of the magnetite of a steatite rock at 298 K, (saturation magnetization, σ = 95.0 J T-1 kg-1) showed two cubic networks and, below Verwey temperature (TV ca.120 K) a monoclinic structure, basing on their cell dimensions and different transitional behaviors when reducing the temperature. A monoclinic structure was ide
J. Braz. Chem. Soc.. Publicado em: 2020-09
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2. Crystal Structure and 1H NMR Experimental and Theoretical Study of Conformers of 5-Methyl-1-(4’-methylphenylsulfonylamino)-1H-[1,2,3]-triazole-4-carboxylic Acid Ethyl Ester and 5-Methyl-1-(phenylsulfonylamino)-1H-[1,2,3]-triazole-4-carboxylic Acid Ethyl Ester
We reported experimental and theoretical investigation of conformers of 1,2,3-triazole derivatives, substances of exclusively synthetic origin, subject of extensive studies, because of several biological properties, such as antiviral, antimicrobial and antileishmaniasis. We reported molecular/supramolecular X-ray structures of antiophidian compounds I and II
J. Braz. Chem. Soc.. Publicado em: 2020-05
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3. Experimental and Theoretical Study of LiMn2O4 Synthesized by the Solution Combustion Method Using Corn Starch as Fuel
Lithium manganese oxide, LiMn2O4, was synthesized in two temperature stages, where the first consisted by an ecofriendly solution combustion method at 300 °C. Finally, the as-burned powders were thermal treated at 500 and 700 °C. The structural and morphological changes were evaluated by the Rietveld method and density functional theory (DFT) calculations.
J. Braz. Chem. Soc.. Publicado em: 2020-02
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4. TITANYL SULPHATE, AN INORGANIC POLYMER: STRUCTURAL STUDIES AND VIBRATIONAL ASSIGNMENT
In this work, anhydrous titanyl sulfate (TiOSO4) was synthesized and characterized by elemental analyses and vibrational spectroscopy by the first time. In order to verify the stability of the crystallographic structure reported in the literature, an optimization calculation of the unit cell geometry was done with the CRYSTAL17 software, and the agreement wi
Quím. Nova. Publicado em: 05/12/2019
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5. Carregamento e caracterização do fármaco carboplatina na microestrutura microporosa do biomaterial granulado bifásico micro e nanoestruturado de fosfato de cálcio
RESUMO As biocerâmicas bifásicas hidroxiapatita/fosfato tricálcico-beta (HA/TCP-β) microporosas são pesquisadas e se destacam em aplicações biomédicas como substitutos dos tecidos ósseos. Estes biomateriais são biocompatíveis e apresentam microestruturas microporosas interconectadas, que permitem sua utilização no reparo do tecido ósseo. Devido
Matéria (Rio J.). Publicado em: 16/09/2019
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6. Carregamento e caracterização do fármaco carboplatina na microestrutura microporosa do biomaterial granulado bifásico micro e nanoestruturado de fosfato de cálcio
RESUMO As biocerâmicas bifásicas hidroxiapatita/fosfato tricálcico-beta (HA/TCP-β) microporosas são pesquisadas e se destacam em aplicações biomédicas como substitutos dos tecidos ósseos. Estes biomateriais são biocompatíveis e apresentam microestruturas microporosas interconectadas, que permitem sua utilização no reparo do tecido ósseo. Devido
Matéria (Rio J.). Publicado em: 20/05/2019
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7. Nb-doped Ti2O3 Films Deposited Through Grid-Assisted Magnetron Sputtering on Glass Substrate: Electrical and Optical Analysis
Abstract Niobium doped dititanium trioxide (Ti2O3:Nb) films were deposited on glass substrates, through grid-assisted magnetron sputtering. The Ti2O3:Nb films were characterized by X-ray diffraction (XRD), electrical conductivity and optical properties. Film deposition was carried out in two different substrate bias modes: DC and unipolar pulsed. Results sho
Mat. Res.. Publicado em: 24/01/2019
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8. Identificación de precipitados en aleaciones U-Nb-Zr tratadas térmicamente a 850 ºC
ABSTRACT At the present, the international goal is to develop and qualify a very high U density fuel for high flux research reactors. The selected U-alloy must present an isotropic crystalline structure at the end of the fuel fabrication process. These types of structures exhibit stable behavior under irradiation. In particular, it is wanted to retain as met
Matéria (Rio J.). Publicado em: 19/07/2018
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9. The long and successful journey of electrochemically active amino acids. From fundamental adsorption studies to potential surface engineering tools.
ABSTRACT Proteins have been the subject of electrochemical studies. It is possible to apply electrochemical techniques to obtain information about their structure due to the presence of five electroactive amino acids that can be oriented to the outside of the peptidic chain. These amino acids are L-Tryptophan (L-Trp), L-Tyrosine (L-Tyr), L-Histidine (L-His),
An. Acad. Bras. Ciênc.. Publicado em: 11/01/2018
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10. Cellular Ceramics Produced from Ceramic Shell: Processing and Characterization
In this work, ceramic shell (mullite source), an industrial solid waste from the lost-wax casting process, after crushing and milling steps, was used and evaluated as an alternative raw material source for the production of cellular ceramics for high temperature applications (> 1400 °C). The obtained ceramic shell powder, with particle size distribution (d5
Mat. Res.. Publicado em: 09/11/2017
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11. Physical and chemical study of lattice kaolinites and their interaction with orthophosphate
ABSTRACT This study covers the evaluation of the structure and the capacity in adsorbing orthophosphate ions of kaolinites collected from sampling sites in Manaus (Brazil). The kaolinites were obtained using physical fractioning (sieving/siphoning) techniques and chemical treatment with HCl, H2SO4, H2O2 and KCl. The investigation of the kaolinite lattices in
An. Acad. Bras. Ciênc.. Publicado em: 2017-09
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12. Study of PtPd Bimetallic Nanoparticles for Fuel Cell Applications
Bimetallic nanoparticles are of special interest for their potential applications for fuel cells, mainly for portable power applications. Among the bimetallic systems, Pt-Pd bimetallic nanoparticles have received great interest as they can be widely used as effective catalysts for various electrochemical reactions. In this work, Pt-Pd alloy bimetallic nanopa
Mat. Res.. Publicado em: 15/05/2017