Ferrite
Mostrando 49-60 de 233 artigos, teses e dissertações.
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49. Prevalência e fatores associados ao colabamento do meato acústico externo entre usuários de um centro de prevenção e reabilitação de deficiências
RESUMO Objetivo: investigar a prevalência do colabamento do meato acústico externo quando utilizados fones supra-aurais e verificar se a ocorrência deste evento é influenciada pelos fatores sexo, idade, cor da pele e orelha em abano. Métodos: a pesquisa do colabamento foi conduzida de forma padronizada por meio do posicionamento de um coxim avulso, pr
Rev. CEFAC. Publicado em: 2017-12
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50. Magnetic topology with axial flux concentration: a technique to improve permanent-magnet motor performance
Abstract This article presents a different topology for the magnetic circuit of permanent-magnet motors, using the concept of Axial Flux Concentration. By means of longitudinal extension of the rotor length beyond the stator core, a substantial increase in the flux per pole is enabled, improving the general performance of the machine. Even in low cost motors
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-12
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51. Efecto del V y el Si Sobre la Microestructura de Depósitos Realizados con Electrodos Tubulares Revestidos de Alto Contenido de Mn (Hadfield)
Abstract: Fe-Mn-C (Hadfield) alloys for surfacing weld deposits have demonstrated excellent wear resistance under high dynamic loads. In recent years, numerous studies have been conducted to improve their wear resistance and performance through the introduction of others alloying elements. In the present work, microstructure and hardness of high Mn surfacing
Soldag. insp.. Publicado em: 09/10/2017
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52. Effect of Ferrite on the Precipitation of σ Phase in Cast Austenitic Stainless Steel Used for Primary Coolant Pipes of Nuclear Power Plants
The effect of ferrite phase on the precipitation of σ phase in a Z3CN20.09M cast austenitic stainless steel (CASS) used for primary coolant pipes of pressurized water reactor (PWR) nuclear power plants was investigated by using isothermal heat-treatment, optical microscopy (OM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA)
Mat. Res.. Publicado em: 28/09/2017
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53. Design of coaxial aircell fixture for the measurement of electromagnetic properties
Abstract Coaxial aircells are designed and fabricated to measure the electromagnetic properties of ferrite materials in the frequency range from 1 MHz to 3.6 GHz. These S-parameters are actually measured connecting the aircell to a vector network analyzer (VNA). The electromagnetic properties such as complex permittivity and complex permeability are extracte
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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54. Synthesis and Characterization of Hybrid Ni0.5Zn0.5Fe2O4@SiO2/chitosan
In this work we evaluate the use of silane agent 3-aminopropyltrimethoxysilane and biopolymer chitosan to functionalize ferrites Ni0.5Zn0.5Fe2O4 using the solvent evaporation method aiming at obtaining hybrid material Ni0.5Zn0.5Fe2O4@SiO2/chitosan for use as a biosensor. The nanoparticles before and after the functionalization showed the major phase Ni0.5Zn0
Mat. Res.. Publicado em: 24/08/2017
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55. Characterization of the Austenite Reformation Mechanisms as a Function of the Initial Ferritic State in a UNS S32304 Duplex Stainless Steel
Aiming to better understand the effects of heat treatment parameters on Ferrite-Austenite phase transformation in a 2304 duplex stainless steel different thermal cycles were applied to this steel in a quenching dilatometer. The obtained microstructures were characterized by optical microscopy, transmission electron microscopy and electron backscatter diffrac
Mat. Res.. Publicado em: 17/08/2017
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56. Potency of ZnFe2O4 Nanoparticles as Corrosion Inhibitor for Stainless Steel; the Pigment Extract Study
The corrosion inhibition of nanoparticulates zinc ferrite (NZF) pigment was studied. The steel samples were immersed in the NZF pigment extract in 3.5 wt. % NaCl. Electrochemical tests such as electrochemical impedance spectroscopy (EIS) and polarization as well as surface analysis were employed to evaluate the effect of NZF on the steel corrosion. The conce
Mat. Res.. Publicado em: 17/08/2017
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57. Preparation of Nickel Ferrite/Carbon Nanotubes Composite by Microwave Irradiation Technique for Use as Catalyst in Photo-Fenton Reaction
Nickel ferrite/multi-walled carbon nanotubes (NiFe2O4/MWCNTs) composite has been rapidly synthesized via microwave irradiation technique. The structural properties of the product was investigated by X-ray diffraction (XRD), N2 adsorption/desorption isotherms, thermogravimetric analysis (TGA), Raman spectroscopy and, scanning electron microscopy (SEM). Cataly
Mat. Res.. Publicado em: 03/08/2017
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58. Embrittlement and Corrosion Decay of a Cast Duplex Stainless Steel
Duplex stainless steels (DSS) are Fe-Cr-Ni-Mo alloys, with low carbon content, which have a favorable combination of mechanical properties and corrosion resistance. These characteristics are mainly attributed to a dual phase and refined microstructure, typical of these alloys, consisting of similar amounts of ferrite and austenite. For this reason, DSS are w
Mat. Res.. Publicado em: 20/07/2017
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59. Facile Synthesis Strategy to Create Mesoporous Magnetic Iron Oxides Using Pectin-Based Precursors
Magnetic iron oxides are of great scientific and technological relevance. Therefore, herein, we report the research on developing methodologies for their sustainable and reproducible preparation. We discuss the synthesis of iron oxides involving citrus pectin as a source of energy (42 MJ kg-1) to promote the formation of the magnetic phases. The method invol
J. Braz. Chem. Soc.. Publicado em: 2017-07
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60. Double Kinetics of Intermetallic Phase Precipitation in UNS S32205 Duplex Stainless Steels Submitted to Isothermal Heat Treatment
One of the most studied deleterious phases in stainless steels is the sigma phase, due to its high potential to decrease the toughness and corrosion resistance of these steels. Eight samples of as-received cold rolled UNS S32205 duplex stainless steel were submitted to isothermal heat treatments at 850 oC during 10, 15, 30, 60, 120, 180, 240, and 300 minutes
Mat. Res.. Publicado em: 26/06/2017