Zobrazeno 1 - 10
of 48
pro vyhledávání: '"Araújo, José Humberto de"'
Publikováno v:
Materials Research, Vol 7, Iss 2, Pp 359-361 (2004)
The effect of heat treatment on illite in air at temperatures ranging from 750 to 1150 °C was studied using the Mössbauer effect in 57Fe. The dependence of the Mössbauer parameters and relative percentage of the radiation absorption area was measu
Externí odkaz:
https://doaj.org/article/224c2180ec004107b3316228dae058d5
Autor:
Silva Júnior, José Pedro, Silva, Régia Pereira, Cazuza, Elio Pessoa, Tenório, Ricardo Bruno de Araújo, Borba, Gilvan Luiz, Mendes, David, Oliveira, Anderson Luiz Pinheiro de, Araújo, José Humberto de, Alcântara, Maurício Lima de
Publikováno v:
Revista de Geociências do Nordeste; v. 6 n. 1 (2020); 10-17
Revista de Geociências do Nordeste
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Revista de Geociências do Nordeste
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
The terrestrial equatorial tropopause is generally analyzed as a region of modest temperature variations and defined only as an interface between the troposphere and the stratosphere. However, recent works has suggested that the tropopause may be a s
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=od______3056::f091df95e16853c52d9c3b45d6bced9c
https://periodicos.ufrn.br/revistadoregne/article/view/18323
https://periodicos.ufrn.br/revistadoregne/article/view/18323
Autor:
Araújo, José Humberto de, Pimentel, Patrícia Mendonça, Dutra, J. L. S., Lima, A. C., Bagnato, Osmar Roberto, Costa, Asenete Frutuoso, Oliveira, Rosane Maria Pessoa Betanio
Publikováno v:
Repositório Institucional da UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
The rare-earth orthoferrites (LnFeO3) are promising materials for various applications, such as chemical sensors, cathode for SOFC, catalysts, among others. In general, these oxides are synthesized at temperatures higher than 700 °C. In this work, n
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=od______3056::cd78a0c9db8fe8081371df5abf3c6d0c
https://repositorio.ufrn.br/jspui/handle/123456789/29401
https://repositorio.ufrn.br/jspui/handle/123456789/29401
Autor:
Araújo, José Humberto de, Soares, João Maria, Galdino, V.B., Conceição, Ozivam Lopes de Aquino, Torres, Marco Antonio Morales, Machado, Fernando L. A.
Publikováno v:
Repositório Institucional da UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Core/shell nanoparticles of CoFe2O4=CoFe2 were prepared by reducing nanoparticles of CoFe2O4 under hydrogen atmospheres. The structure, morphology and room temperature magnetization of the core/ shell nanoparticles were analyzed by X-ray diffraction,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=od______3056::01475063a39267c51f2115d4225ce556
https://repositorio.ufrn.br/jspui/handle/123456789/29364
https://repositorio.ufrn.br/jspui/handle/123456789/29364
Autor:
Araújo, José Humberto de, Pimentel, Patrícia Mendonça, Oliveira, Rosane Maria Pessoa Betânio, Oliveira, Filipe Silva, Bagnato, Osmar Roberto, Melo, Dulce Maria de Araújo
Publikováno v:
Repositório Institucional da UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
The main purpose of this work was to obtain Sm-Sr nickelates nanoparticles with Ruddelsden-Popper type structuresobtained by a simple process such as gelatin synthesis. The powders were calcinated at 900 ºC and characterized by X-ray diffraction,the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=od______3056::a478d7bcdf0349533b67993edeb2034c
https://repositorio.ufrn.br/jspui/handle/123456789/29359
https://repositorio.ufrn.br/jspui/handle/123456789/29359
Autor:
Araújo, José Humberto de, Soares, J. M., Cabral, F. A. O., Machado, F. L. A., Ginani, Marconi Floripe
Publikováno v:
Repositório Institucional da UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
High purity BaFe12O19 samples were synthesized by an ionic-coordination-reaction (ICR) technique using chitosan as a complex agent. The mean size Dm of the particles and their magnetic properties were controlled by varying the concentration of chitos
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=od______3056::4034dd7ef711923438484fb2a6349d40
https://repositorio.ufrn.br/jspui/handle/123456789/29191
https://repositorio.ufrn.br/jspui/handle/123456789/29191
Autor:
Araújo, José Humberto de, Moreira, M. L., Soares, J. M., Azevedo, W. M. de, Rodrigues, A. R., Machado, F. L. A.
Publikováno v:
Repositório Institucional da UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Nanoparticles of the manganite were synthesized using the Pechini process and their structural properties were characterized by X-ray diffraction (XRD) and by transmission electron microscopy (TEM). The magnetization of compacted powders was measured
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=od______3056::0f0255e851a1af783e7f324e49da802d
https://repositorio.ufrn.br/handle/123456789/45362
https://repositorio.ufrn.br/handle/123456789/45362
Autor:
Araújo, José Humberto de, Soares, J. M., Machado, F. L. A., Cabral, F. A. O., Ginani, Marconi Floripe
Publikováno v:
Repositório Institucional da UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Samples of FexAg100−x, with 2% x50%, were produced using a new preparation route based on the ionic coordination reaction technique. X-ray diffraction and transmission electronic microscopy showed that the samples are granular alloys and that they
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=od______3056::6230807c21db89c121c731edeafceaa7
https://repositorio.ufrn.br/jspui/handle/123456789/29357
https://repositorio.ufrn.br/jspui/handle/123456789/29357
Autor:
Araújo, José Humberto de, Souza Filho, A. G., Faria, J. L. B., Guedes, I., Sasaki, José Marcos, Freire, P. T. C., Mendes Filho, J., Xavier Jr, M. M., Cabral, Francisco de Assis Olímpio, Costa, J. A. P. da, Freire, V. N.
Publikováno v:
Repositório Institucional da UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
We have performed x-ray, electrical resistivity, and Raman scattering measurements in La0.70Sr0.30Mn12xFexO3 manganites, with x varying from 0 to 0.40. The appearance of new peaks in the Raman spectra as the Fe content increases is attributed to eith
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=od______3056::bb823351ef757677276a419bb44ead3f
https://repositorio.ufrn.br/handle/123456789/45360
https://repositorio.ufrn.br/handle/123456789/45360
Autor:
Araújo, José Humberto de, Feitosa, Carlos Chesman de Araújo, Dumelow, T., Xavier Jr, M. M., Cabral, F. A. O.
Publikováno v:
Repositório Institucional da UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
Universidade Federal do Rio Grande do Norte (UFRN)
instacron:UFRN
The effect of Fe doping (
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=od______3056::c716679daa88f1da6ae9abdf95d0f95a
https://repositorio.ufrn.br/jspui/handle/123456789/28978
https://repositorio.ufrn.br/jspui/handle/123456789/28978