Nb Al
Mostrando 1-12 de 174 artigos, teses e dissertações.
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1. Quando se deve repetir endoscopia em pacientes com dispepsia?
Pacientes com dispepsia já investigada com endoscopia podem necessitar de nova endoscopia nas seguintes situações:
– Controle de erradicação de H. pylori em pacientes com úlcera gástrica ou duodenal, pelo menos 4 semanas após o tratamento de erradicação;
– Controle de cicatrização de úlcera gástrica, após 8 a 12 semanas de u
Núcleo de Telessaúde Rio Grande do Sul. Publicado em: 12/06/2023
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2. Qual o período ideal para gestante realizar tratamento odontológico?
Para o tratamento odontológico da gestante recomenda-se que o dentista esteja atento ao período gestacional e ao problema odontológico a ser tratado. O período ideal e mais seguro para o tratamento odontológico é durante o segundo trimestre da gestação
. No entanto, se a gestante necessitar de tratamento de urgência e emergência, esses dev
Núcleo de Telessaúde Amazonas. Publicado em: 12/06/2023
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3. Fast Catalytic Pyrolysis of Tetradecanoic Acid: Formation of Ketones as Intermediate Compounds in the Production of Hydrocarbons
This work aimed to compare two different catalysts in the production of a long chain ketone, intermediate in the production of hydrocarbons, during pyrolysis of tetradecanoic acid as a model fatty acid. The studied variables were the temperature, 450 and 600 ºC, and catalysts, γ-Al2O3 and Nb2O5, the latter has never been studied under such conditions. Pyro
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Microstructural Evolution and Phase Transformation of a Ti-5Nb-5Al Alloy During Annealing Treatment
The microstructural evolution and phase transformation of a Ti-5Nb-5Al alloy during isothermal annealing treatment were studied in this paper. The microstructural evolution was analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with X-ray energy dispersive spectroscopy (EDS) and electron backscattering diffraction (EBSD). The fi
Mat. Res.. Publicado em: 05/12/2019
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5. Microstructure and Thermal Analyses of Cu87-xAl13Nbx High-Temperature Shape Memory Alloys
This paper presents a thermal and microstructural characterization of Cu87-xAl13Nbx (wt%) high temperature shape memory alloys (HTSMA), with Nb contents ranging from 1 to 3%. The alloys were obtained by arc melting under argon atmosphere. Thermal characterization was performed by differential scanning calorimetry (DSC), revealing that the phase martensitic t
Mat. Res.. Publicado em: 28/11/2019
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6. Nb-Al Binary System: Reevaluation of the Solubility Limits of the (Nb), Nb3Al, Nb2Al and NbAl3 Phases at High Temperatures
In this work a re-investigation of the solubility limits of the (Nb), Nb3Al, Nb2Al and the Nb-rich side of the NbAl3 phases on the Nb-Al system is presented. Alloys in the binary fields ((Nb)+Nb3Al, Nb3Al+Nb2Al and Nb2Al+NbAl3) were arc-melted, and then equilibrated at 1000, 1200 and 1400 ºC. The phases were confirmed via X-ray powder diffractometry, and th
Mat. Res.. Publicado em: 25/11/2019
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7. Interrelation Among Morphology, Mechanical Properties and Oxidation Behavior of NbxAlyNz Thin Films
NbxAlyNz thin films were deposited by magnetron sputtering reactive technique with (y/x+y) ratio varying from 0 to 0.4, in order to maintain aluminum atoms inside NbN matrix in solid solution. GAXRD analyses revealed that the crystalline phase obtained for NbxAlyNz thin films was B1-NbN with a lattice constant shrinkage as Al concentration at these coatings
Mat. Res.. Publicado em: 07/11/2019
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8. Obtaining Composites Powders of Al2 O3 / Ni and Al2 O3 / Nb by Mechanical Alloying
Mechanical alloying (MA) can be highlighted among the various methods and powder processing forms, which consists of producing homogeneous materials from elementary powders. This process is of paramount importance as it has the ability to reduce the particle size of the powders and can often promote bonding between elements which have low interaction and wet
Mat. Res.. Publicado em: 14/10/2019
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9. Ballistic Behavior of New Alumina Composites Reinforced with Niobo-Phosphate Glass
This work aimed to produce and evaluate the ballistic behavior of niobo-phosphate glass-doped alumina composites. The niobo-phosphate glass (30% Nb2O5- 30% P2O5- 20% CaO - 20% CaF2, by mol) were added to the alumina in six different weight percentages. The composite with the highest densification, measured by the Archimedes assay, was used for the ballistic
Mat. Res.. Publicado em: 23/09/2019
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10. Influence of Directional Solidification on the Mechanical Properties of Cu-Al-Be-Nb-Ni Alloy
Copper-based polycrystalline shape memory alloys (SMAs) have limitations for many practical applications due to their low superelasticity and low ductility. In order to overcome this situation, in recent years, the production of copper-based SMAs by directional solidification process has attracted the interest of many researches. In this sense, the present w
Mat. Res.. Publicado em: 05/09/2019
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11. Microstructural Adjustments and Tensile Properties of a Hot-Forged Ti−22Al−23Nb−3V−Y Alloy
Microstructures and tensile properties of a hot forged Ti−22Al−23Nb−3V−Y alloy were investigated systematically. Different heat treatments were performed to adjust the wrought microstructure to optimize tensile properties. It was found that features of O phase precipitates and its volume fraction was rather sensitive to the cooling rate after the sol
Mat. Res.. Publicado em: 19/08/2019
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12. Influence of Mechanical Cycling on Residual Strain in Superelastic Cu-Al-Be-Nb Alloys
The understanding of the stabilization mechanism of martensite used to obtain alloys with high hysteresis and the possibility of recovering this martensite (residual strain) by heating at temperatures higher than As and Af have been fundamental for application in bonding devices. One of the possibilities to enhance residual strain is through mechanical cycli
Mat. Res.. Publicado em: 15/07/2019