Zobrazeno 1 - 10
of 67
pro vyhledávání: '"Rodrigo M. S. de Oliveira"'
Publikováno v:
Energies, Vol 17, Iss 13, p 3173 (2024)
We suggest a new method of localization of partial discharges in high-power electrical systems. Ozone in a hydrogenerator is produced by chemical reactions induced by partial discharges in the stator region. The transport of ozone in an operating hyd
Externí odkaz:
https://doaj.org/article/71c64bbd10494ba2898063dc281ef338
Publikováno v:
Energies, Vol 17, Iss 9, p 2208 (2024)
In this paper, we present an unprecedented method based on Kohonen networks that is able to automatically recognize partial discharge (PD) classes from phase-resolved partial discharge (PRPD) diagrams with features of various simultaneous PD patterns
Externí odkaz:
https://doaj.org/article/95e2408733804353b446fc74a297fa71
Publikováno v:
Energies, Vol 17, Iss 8, p 1799 (2024)
In this paper, we develop a finite-difference time-domain (FDTD) model in which the time-evolving electrical conductivity of the air ionization plasma in DC voltage needed-plate setup is represented. Maxwell’s equations are solved using the FDTD me
Externí odkaz:
https://doaj.org/article/90f63b5c12a7425899f66a3f95787059
Autor:
Rodrigo M. S. de Oliveira, Júlio S. Nascimento, Daiyuki M. Fujiyoshi, Thiago S. de Lima, Anderson J. C. Sena
Publikováno v:
Journal of Microwaves, Optoelectronics and Electromagnetic Applications, Vol 21, Iss 3, Pp 427-444 (2022)
Abstract A numerical model based on the finite-difference timedomain (FDTD) method is developed for calculating discharge currents and fields produced due air ionization between two electrodes. Electric conductivity σ of the ionized channel between
Externí odkaz:
https://doaj.org/article/83cfdefb0ad14d40bcb87787183200bf
Autor:
Rodrigo M. S. de Oliveira, Gustavo G. Girotto, Licinius D. S. de Alcantara, Nathan M. Lopes, Victor Dmitriev
Publikováno v:
Energies, Vol 16, Iss 24, p 8072 (2023)
In this paper, a three-dimensional turbulent fluid dynamics numerical model of a 311 MVA full hydroelectric power plant unit is made, using the finite element method, to study and understand the ozone transport mechanisms inside the enclosured electr
Externí odkaz:
https://doaj.org/article/b6ff2310afc848b296fa906acdef094a
Autor:
Rodrigo M. S. de Oliveira, Ronaldo F. Zampolo, Licinius D. S. Alcantara, Gustavo G. Girotto, Frederico H. R. Lopes, Nathan M. Lopes, Fernando S. Brasil, Júlio A. S. Nascimento, Victor Dmitriev
Publikováno v:
Energies, Vol 16, Iss 19, p 6947 (2023)
We present a synergistic investigation into ozone production dynamics within a high-voltage reaction chamber operating from 1.75 kV to 10 kV, at 60 Hz. The output ozone concentration dependence on a 60 Hz root mean square high-voltage for an air inpu
Externí odkaz:
https://doaj.org/article/f73f92bbbbee43019913374563262e50
Publikováno v:
Sensors, Vol 23, Iss 15, p 6900 (2023)
A novel graphene antenna composed of a graphene dipole and four auxiliary graphene sheets oriented at 90∘ to each other is proposed and analyzed. The sheets play the role of reflectors. A detailed group-theoretical analysis of symmetry properties o
Externí odkaz:
https://doaj.org/article/014d5f4c6a894ef0ac9c44acd424dc3f
Autor:
Adonis F. R. Leal, Rodrigo M. S. de Oliveira, Nathan M. Lopes, Thiago S. de Lima, Eduardo R. Ferreira, Nilton Rodolfo N. M. Rodrigues
Publikováno v:
Journal of Microwaves, Optoelectronics and Electromagnetic Applications, Vol 20, Iss 2, Pp 307-319 (2021)
Abstract The Amazon region has high lightning occurrence rates, with many lightning hot spots. Different rivers cross the Amazon rainforests and the people that live there use these rivers as roads to go from one place to another. Every year, lightni
Externí odkaz:
https://doaj.org/article/f4ba4756da714d2cb1115d36d03d28ba
Publikováno v:
Energies, Vol 16, Iss 3, p 1111 (2023)
In this paper, we propose a mitigation method for reducing lightning-induced insulator voltages based on the installation of low-voltage surge arresters aligned parallelly to the insulator. The three-dimensional finite-difference time-domain (FDTD) m
Externí odkaz:
https://doaj.org/article/e7bdf1fe975a4e22ab41421720b58588
Autor:
Miércio C. de Alcântara Neto, Gervásio P. S. Cavalcante, Rodrigo M. S. de Oliveira, Fábio F. Ribeiro, Flávio H. C. S. Ferreira, Fabrício J. B. Barros, José F. S. de Almeida
Publikováno v:
Journal of Microwaves, Optoelectronics and Electromagnetic Applications, Vol 19, Iss 3, Pp 366-378 (2020)
Abstract In this work, a compact ultra-wide-band microstrip antenna loaded with C-shaped parasitic elements, for Digital Video Broadcasting - Terrestrial (DVB-T) and LTE 450 / 700 signal reception, is designed and presented. The proposed antenna is n
Externí odkaz:
https://doaj.org/article/6fa541dbd7d84784a38bb00c774e0c55