RSS 1.0Artigos - Física e Química - FEG
Browse by
Recent Submissions
-
Spin in two-dimensional fermion motion with circular symmetry
de Castro, A. S.
; (Proceedings of Science, 2021) [Trabalho apresentado em evento]
We study two-dimensional fermion motion with circular symmetry using both 3+1 and 2+1 Dirac equations with a general Lorentz structure. Using a different approach than usual, we fully develop the formalism for these equations ... -
Analysis of the Mechanical Properties of Anodized Al-Si Alloys
Regone, Natal Nerímio; ; ; ; Codaro, Eduardo Norberto ; Acciari, Heloisa Andréa (Materials Research, 2022) [Artigo]
Aluminum alloys have been widely used in multiple applications, such as in civil construction and engine pistons. They are subjected to loads that may impair their mechanical properties. Thereby, this research aims to study ... -
Cold Atmospheric Pressure Plasma Is Effective against P. gingivalis (HW24D-1) Mature Biofilms and Non-Genotoxic to Oral Cells
de Morais Gouvêa Lima, Gabriela; Carta, Celina Faig Lima ; Borges, Aline Chiodi ; ; ; ; ; Kostov, Konstantin Georgiev ; Koga-Ito, Cristiane Yumi (Applied Sciences (Switzerland), 2022) [Artigo]
Featured Application: Helium cold atmospheric plasma jet is safe to oral cells’ DNA in applications from 1 to 7 min. The effects of helium cold atmospheric pressure plasma (He-CAPP) jet on Porphyromonas gingivalis (HW24D-1) ... -
Ethanol as a renewable biofuel: Combustion characteristics and application in engines
; ; ; Mariños, Diego J.; ; ; ; de Carvalho, João A. (Energy, 2022) [Resenha]
The present review article aims to study different aspects involving ethanol combustion and utilization. The review deals with the production and sustainability of corn-based and sugarcane-based ethanol as a starting point ... -
Experimental investigation of flameless combustion of biodiesel
Orati, Edson; Veríssimo, Anton S. ; ; ; Carvalho, João A. (Energy, 2022) [Artigo]
A laboratory-scale combustor was investigated under flameless biodiesel combustion. The biofuel was used due to its importance as a green fuel substitute for conventional fossil diesel, in order to reduce the emission of ... -
Determination of the kinematic parameters from SNe Ia and cosmic chronometers
Benndorf, D.; Jesus, J. F. ; Pereira, S. H. (European Physical Journal C, 2022) [Artigo]
In this work, by assuming a spatially flat Universe, we have tested 8 kinematic parametrization models with H(z) data from Cosmic Chronometers and SNe Ia from Pantheon compilation. Our aim is obtain the current values for ... -
Degeneracy pressure of mass dimension one fermionic fields and the dark matter halo of galaxies
Pereira, S. H. (International Journal of Modern Physics D, 2022) [Artigo]
In this paper, the recently proposed mass dimension one fermionic field is supposed to be responsible for the dark matter (DM) halo around galactic nuclei, through the quantum degeneracy pressure effect of the field. It ... -
Mass dimension one fermions: Constructing darkness
; Silva, Julio M. Hoff da; ; ; Pereira, Saulo H. ; (Physics Reports, 2022) [Resenha]
Let Θ be the Wigner time reversal operator for spin half and let ϕ be a Weyl spinor. Then, for a left-transforming ϕ, the construct ζλΘϕ∗ yields a right-transforming spinor. If instead, ϕ is a right-transforming spinor, ... -
Dark matter from torsion in Friedmann cosmology
Pereira, S. H.; Vicente, A. M. ; Jesus, J. F. ; (European Physical Journal C, 2022) [Artigo]
A cosmological model in an Einstein–Cartan framework endowed with torsion is studied. For a torsion function assumed to be proportional to Hubble expansion function, namely ϕ= - αH, the contribution of torsion function as ... -
A pilot study on canonical gravity with mass dimension one fermions
; ; Pereira, S. H. (Journal Of High Energy Physics, 2022) [Artigo]
The mass dimension one (MDO) fermionic field is built on a complete set of dual-helicity eigenspinors of the charge conjugation operator, which obeys the statistic of Fermi-Dirac. These spinors are a potential candidates ... -
Fermionic wave functions and Grassmann fields as possible sources of dark energy
; Pereira, S. H.; ; ; Jesus, J. F. (European Physical Journal C, 2022) [Artigo]
We study a cosmological model with a fermionic field which can be interpreted as a source of dark energy in the universe. Two different approaches were considered, the first one with a massless fermionic field represented ... -
Frozen core-annular flow model for effervescent atomizer
Amaro, Jordan; ; ; Carvalho Jr, Joao A. de (Journal Of The Brazilian Society Of Mechanical Sciences And Engineering, 2022) [Artigo]
This research consists in the development of a frozen core-annular flow model to estimate the physical variables of the fluids at the exit orifice of the effervescent atomizer. The model is validated through experimental ... -
Testing a varying-A model for dark energy within co-varying physical couplings framework
; ; ; Jesus, J. F.; Pereira, S. H. (Monthly Notices Of The Royal Astronomical Society, 2022) [Artigo]
The Co-varying Physical Couplings (CPC) framework is a modified gravity set up assuming Einstein Field Equations wherein the quantities {G, c, A} are promoted to space-time functions. Bianchi identity and the requirement ... -
Hamiltonian analysis and positivity of a new massive spin-2 model
; Dalmazi, Denis; (Classical and Quantum Gravity, 2022) [Artigo]
Recently a new model has been proposed to describe free massive spin-2 particles in D dimensions in terms of a non symmetric rank-2 tensor e μν and a mixed symmetry tensor B μ[αβ]. The model is invariant under linearized ... -
Higher spin analogs of linearized topologically massive gravity and linearized new massive gravity
Dalmazi, D.; (Physical Review D, 2021) [Artigo]
We suggest a new spin-4 self-dual model (parity singlet) and a new spin-4 parity doublet in D=2+1. They are of higher order in derivatives and are described by a totally symmetric rank-4 tensor without extra auxiliary ... -
Plasma polymer deposition of neutral agent carvacrol on a metallic surface by using dielectric barrier discharge plasma in ambient air
Getnet, Tsegaye Gashaw; da Cruz, Nilson Cristino ; Kayama, Milton Eiji ; Rangel, Elidiane Cipriano (Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST, 2020) [Trabalho apresentado em evento]
This experiment was conducted by newly designed home-made planar type DBD plasma generator in ambient, with industrial argon as the primary plasma-forming and a carrier gas of monomer. Natural agent Carvacrol monomer was ... -
Development of platinum-niobium as a CO tolerant catalyst for PEFC operating with CO contaminated hydrogen
; ; Ciapina, Eduardo Gonçalves; ; (ECS Transactions, 2015) [Trabalho apresentado em evento]
This paper presents the results of a bimetallic Pt3Nb/C catalyst prepared by thermal treatment in dilute reductive atmosphere (5% H2 in Ar) to obtain a CO-tolerant catalyst. The thermal treatment leads to the formation of ... -
Can mechanical agitation induce stable physicochemical changes on a solvent?
Zacharias, Carlos Renato; de França Silva, Mariana (International Journal of High Dilution Research, 2013) [Artigo]
Why do serial agitations are so important to prepare a homeopathic medicine? This question has been discussed for two centuries but it still remains opened. Accordingly some experimental evidences, agitated (and diluted) ... -
Um esboço da história do conceito de trabalho virtual e suas aplicações
Cindra, José Lourenço (Revista Brasileira de Ensino de Fisica, 2008) [Artigo]
In this work is discussed the question concerning the origin and development of the principle of virtual work as a fundamental principle in the study of the analytical mechanics, and particularly of the static equilibrium ... -
Perturbative bosonization from two-point correlation functions
Dalmazi, D.; Souza Dutra, A. ; Hott, Marcelo (Physical Review D - Particles, Fields, Gravitation and Cosmology, 2003) [Artigo]
Here we address the problem of bosonizing massive fermions without making expansions in the fermion masses in both massive [Formula Presented] and [Formula Presented] with N fermion flavors including also a Thirring coupling. ...