Zobrazeno 1 - 10
of 25
pro vyhledávání: '"Gevaldo L. de Almeida"'
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 908:172-181
Thermal neutron radiographs acquired under high beam divergences suffer the impact of intense penumbrae degrading their final quality. As a divergence reduction is not always feasible, one possible alternative is an a posteriori treatment to restore
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::80ea330ecdeb7e8a4f456d36efa2a8ff
https://doi.org/10.1016/j.nima.2018.08.055
https://doi.org/10.1016/j.nima.2018.08.055
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 871:127-134
The quality of a neutron radiograph is strongly dependent upon the features of the acquisition system. Most of them, such as detector resolution, electronic noise and statistical fluctuation can hardly be improved. Yet, a main parameter ruling the im
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::df4b31fcc2675e9a7232273c141ebdb7
https://doi.org/10.1016/j.nima.2017.07.055
https://doi.org/10.1016/j.nima.2017.07.055
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 838:129-136
This work posits a novel approach to characterize the divergence of a neutron beam emerging from a reactor port. Unlike the usual inverse of the L/D ratio, the term divergence as employed here refers to the deviation from an ideal parallel beam emitt
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::d11839b6a11dc672e67d151e47fbc26c
https://doi.org/10.1016/j.nima.2016.09.020
https://doi.org/10.1016/j.nima.2016.09.020
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 652:634-637
Spatial structure of an object can be perceived by the stereoscopic vision provided by eyes or by the parallax produced by movement of the object with regard to the observer. For an opaque object, a technique to render it transparent should be used,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::88b1615210139f6e425f0637d2ebbbbe
https://doi.org/10.1016/j.nima.2010.09.051
https://doi.org/10.1016/j.nima.2010.09.051
Autor:
Rosanne C. A. A. Furieri, Marcelo J. Gonçalves, Ricardo Tadeu Lopes, Maria Ines Silvani, Gevaldo L. de Almeida
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 263:253-257
The impact of the divergence of a thermal neutron beam and the scattered neutrons on the quality of tomographic images acquired by transmission have been evaluated by using a third generation tomographic system incorporating neutron collimators under
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ed3cc7a13715ed48a7cd0485d6a7bf9a
https://doi.org/10.1016/j.nimb.2007.04.237
https://doi.org/10.1016/j.nimb.2007.04.237
Publikováno v:
Repositório Institucional da UFRJ
Universidade Federal do Rio de Janeiro (UFRJ)
instacron:UFRJ
Universidade Federal do Rio de Janeiro (UFRJ)
instacron:UFRJ
Submitted by Jairo Amaro (jairo.amaro@sibi.ufrj.br) on 2019-07-15T18:47:12Z No. of bitstreams: 1 2008_ALMEIDA_EMA_v13_p53-65-min.pdf: 289711 bytes, checksum: a1caa4304ed47dc544eaf2118a8a22c4 (MD5) Made available in DSpace on 2019-07-15T18:47:12Z (GMT
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::52a10274a066cc19491b146145876ba3
https://doi.org/10.1007/s10666-006-9072-4
https://doi.org/10.1007/s10666-006-9072-4
Autor:
Rosanne C. A. A. Furieri, Maria Ines Silvani, Gevaldo L. de Almeida, Ricardo Tadeu Lopes, Marcelo J. Gonçalves
Publikováno v:
Brazilian Journal of Physics, Volume: 34, Issue: 3a, Pages: 767-772, Published: SEP 2004
Brazilian Journal of Physics v.34 n.3a 2004
Brazilian Journal of Physics
Sociedade Brasileira de Física (SBF)
instacron:SBF
Brazilian Journal of Physics v.34 n.3a 2004
Brazilian Journal of Physics
Sociedade Brasileira de Física (SBF)
instacron:SBF
A computer program to simulate tomographic images generated by transmitted radiation was developed. The algorithm uses a deterministic approach to generate the projections, which supply an existing image reconstruction software. A dispersion associat
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6f36597f67c134dde617ae33abebddf9
https://doi.org/10.1590/s0103-97332004000500016
https://doi.org/10.1590/s0103-97332004000500016
Autor:
Maria Ines Silvani, Ademarlaudo F. Barbosa, Ricardo Tadeu Lopes, Gevaldo L. de Almeida, Delson Braz, Edgar Francisco Oliveira de Jesus
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 213:294-299
A gaseous position sensitive detector originally designed to operate with X-rays has been modified for using in thermal neutron tomographic systems. This modification included the replacing of the standard argon–methane mixture by 3He-enriched heli
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a732132482ab3d51d4221ab1dbc0e2a6
https://doi.org/10.1016/s0168-583x(03)01621-5
https://doi.org/10.1016/s0168-583x(03)01621-5
Autor:
Maria Ines Silvani Souza, Rosanne C. A. A. Furieri, Edgar Oliveira de Jesus, Ademarlaudo F. Barbosa, Gevaldo L. de Almeida, Ricardo Tadeu Lopes
Publikováno v:
Brazilian Journal of Physics v.33 n.2 2003
Brazilian Journal of Physics
Sociedade Brasileira de Física (SBF)
instacron:SBF
Brazilian Journal of Physics, Volume: 33, Issue: 2, Pages: 286-290, Published: JUN 2003
Brazilian Journal of Physics
Sociedade Brasileira de Física (SBF)
instacron:SBF
Brazilian Journal of Physics, Volume: 33, Issue: 2, Pages: 286-290, Published: JUN 2003
In this work, tomographic images of the same object have been taken with 25 keV X-rays and thermal neutrons (E=0.025 eV) aiming to demonstrate that thermal neutron tomography in some cases is a complementary technique to the X-ray tomography, such as
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b123ef27d23053cad19bb218181d4eb2
https://doi.org/10.1590/s0103-97332003000200023
https://doi.org/10.1590/s0103-97332003000200023
Publikováno v:
AIP Conference Proceedings.
In this study, the aim was to evaluate capabilities and constraints of radiographic imagery using thermal neutrons and gamma-rays as tools to identify the type of technique employed in ceramics manufacturing especially that used in prehistoric Brazil
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1ab7ed86f7468fb07f53f195e7442f20
https://doi.org/10.1063/1.4901773
https://doi.org/10.1063/1.4901773