Rosa BLT, Fujisawa K, Santos JCC, Zhang T, Matos MJS, Sousa FB, Barbosa TC, Lafeta L, Ramos SLLM, Carvalho BR, et al. Investigation of spatially localized defects in synthetic $\mathrmWS_2$ monolayers. Phys. Rev. B [Internet]. 2022;106 :115301. Publisher's Version
Velten H, Delladea D, Primola A. Um critério energético para o desenvolvimento de vida em um exoplaneta. Cadernos de Astronomia [Internet]. 2022;3 (2) :59–65. Publisher's Version
Almeida AMR, Fabris JC, Daouda MH, Kerner R, Velten H, Hipólito-Ricaldi WS. Brans–Dicke Unimodular Gravity. Universe [Internet]. 2022;8 (8). Publisher's VersionAbstract
We propose a unimodular version of the Brans–Dicke theory designed with a constrained Lagrangian formulation. The resulting field equations are traceless. The vacuum solutions in the cosmological background reproduce the corresponding solutions of the usual Brans–Dicke theory but with a cosmological constant term. A perturbative analysis of the scalar modes is performed and stable and unstable configurations appear, in contrast with the Brans–Dicke case for which only stable configurations occur. On the other hand, tensorial modes in this theory remain the same as in the traditional Brans–Dicke theory.
Figueiredo MTD, Ferreira GMD, Lopez MAR, das Graças Cardoso M, de Oliveira JE, Bianchi RF, Ferreira GMD, Mageste AB. Immobilization of Anthocyanin in Polymeric Film to Obtain a Colorimetric Sensor for Detection of Copper in Cachaça. Food Analytical Methods. 2022 :1–19.
da Silva Lima G, de Souza LV{\'ıcio, Farias MR, Caldeira AG, de Andrade Aoyama E. CONHECIMENTO DOS ADOLESCENTES COM RELA\cCÃO ÀS INFEC\cCÕES SEXUALMENTE TRANSMISSÍVEIS. Revista Brasileira Interdisciplinar de Saúde. 2022.
da Silva FBR, Araújo FGS, von Krüger FL, Silva GJB, Batista RJC, Manhabosco T{\'ıse M. Characterization of Magnetic Tailings from Phosphate-Ore Processing in Alto Parana{\'ıba. Materials Research. 2022;25.
Franca LG, dos Santos PL, Pander P, Cabral MGB, Cristiano R, Cazati T, Monkman AP, Bock H, Eccher J. Delayed Fluorescence by Triplet–Triplet Annihilation from Columnar Liquid Crystal Films. ACS Applied Electronic Materials [Internet]. 2022 :null. Publisher's Version
Fabris JC, Alvarenga MH, Hamani-Daouda M, Velten H. Nonconservative unimodular gravity: a viable cosmological scenario?. The European Physical Journal C [Internet]. 2022;82 (6) :522. Publisher's VersionAbstract
In this work we review the issue of imposing the conservation of the energy–momentum tensor as a necessary condition to recover the equivalence between the unimodular gravity and General Relativity (GR) equipped with a cosmological constant. This procedure is usually interpreted as an ad hoc imposition on the unimodular theory's structure. Whereas the consequences of avoiding the conservation of the total energy–momentum tensor has been already introduced in the literature, it has been not widely explored so far. We study an expanding universe sourced by a single effective perfect fluid such that the null divergence of its energy–momentum tensor is not imposed. As we shall show, in this scheme, the unimodular theory has its own conservation equation obtained from the Bianchi identities. We explore the evolution of the homogeneous and isotropic expanding background and show that a viable cosmological scenario exists. Also, we consider scalar perturbations with particular attention given to the gauge issue. We show that contrary to the traditional unimodular theory where the synchronous and longitudinal (newtonian) gauge for cosmological perturbations are not permitted, if the conservation of the energy–momentum is relaxed the scalar perturbations in the synchronous condition survive and present a growing mode behavior. We study therefore a new cosmological scenario in which the dynamics of the universe transits from the radiative phase directly to a accelerated one but allowing thus for structure formation.
Batista AB, Stanley M, de Brito ACF, Vasconcellos R, Munk M, José-Bueno M, Godoy C, de Alvarenga ÉC, de Vasconcelos CKB, Righi A, et al. Improved bioceramic coatings reinforced by nanostructured talc. Surface and Coatings Technology [Internet]. 2022;441 :128589. Publisher's VersionAbstract
Nano-talc was successfully incorporated in the hydroxyapatite matrix via pulsed electrodeposition after being obtained using an eco-friendly liquid-phase exfoliation process. Scanning electron microscopy, atomic force microscopy, X-ray spectroscopy, Raman spectroscopy, corrosion and wear resistance, and cytocompatibility tests were used to characterize the biocomposite ceramics. Talc significantly improves the nanomechanical and wear properties of bioceramics (i.e., higher stiffness, reduced friction coefficient, and lower wear damage) as well as corrosion resistance. Talc does not induce cytotoxic activity in in vitro cells and may induce bone maturation as per biocompatibility tests.
Fazolo RE, Amendola L, Velten H. Skewness as a test of dark energy perturbations. Phys. Rev. D [Internet]. 2022;105 :103521. Publisher's Version
Martins LGP, Carvalho BR, Occhialini CA, Neme NP, Park J-H, Song Q, Venezuela P, Mazzoni MSC, Matos MJS, Kong J, et al. Electronic Band Tuning and Multivalley Raman Scattering in Monolayer Transition Metal Dichalcogenides at High Pressures. ACS Nano [Internet]. 2022 :null. Publisher's Version
Gomes AH. Deformations of the canonical commutation relation and Lorentz symmetry violation. arXiv preprint arXiv:2205.02044. 2022.
Omwoyo E, Belich H, Fabris JC, Velten H. Remarks on the black hole shadows in Kerr-de Sitter space times. The European Physical Journal C. 2022;82 (5) :1–17.
Guimarães MHU, Muramatsu M, Passos MM. UMA ANÁLISE CRÍTICA SOBRE A IMPLEMENTA\cCÃO DO SCALE-UP NO INSTITUTO DE FÍSICA DA UNIVERSIDADE DE SÃO PAULO. Experiências em Ensino de Ciências. 2022;17 (1) :57–75.
de Lima FP, Guimarães MHU, Passos MM. Astronomical phenomena: a teaching proposal. Research, Society and Development [Internet]. 2022;11 (6) :e15211629011. Publisher's Version
Ferrari GA, Chacham H, de Oliveira AB, Matos MJS, Batista RJC, Meireles LM, Barboza APM, Silvestre I, Neves BRA, Lacerda RG. Graphene nanoencapsulation action at an air/lipid interface. Journal of Materials Science. 2022 :1–10.
Pereira NM, Rezende NP, Cunha THR, Barboza APM, Silva GG, Lippross D, Neves BRA, Chacham H, Ferlauto AS, Lacerda RG. Aerosol-Printed MoS2 Ink as a High Sensitivity Humidity Sensor. ACS Omega [Internet]. 2022 :null. Publisher's Version
Castro e Silva A, Bernardes AT, Barbosa EAG, das Chagas IAS, Dáttilo W, Reis AB, Ribeiro SP. Successive Pandemic Waves with Different Virulent Strains and the Effects of Vaccination for SARS-CoV-2. Vaccines [Internet]. 2022;10 (3). Publisher's VersionAbstract
One hundred years after the flu pandemic of 1918, the world faces an outbreak of a new severe acute respiratory syndrome, caused by a novel coronavirus. With a high transmissibility, the pandemic has spread worldwide, creating a scenario of devastation in many countries. By the middle of 2021, about 3% of the world population had been infected and more than 4 million people had died. Different from the H1N1 pandemic, which had a deadly wave and ceased, the new disease is maintained by successive waves, mainly produced by new virus variants and the small number of vaccinated people. In the present work, we create a version of the SIR model using the spatial localization of persons, their movements, and considering social isolation probabilities. We discuss the effects of virus variants, and the role of vaccination rate in the pandemic dynamics. We show that, unless a global vaccination is implemented, we will have continuous waves of infections.
Gonçalves JA, dos Santos OFP, Batista RJC, Azevedo S. Optical properties of boron nitride nanoribbons with reconstruted edges. Solid State Communications [Internet]. 2022 :114627. Publisher's VersionAbstract
In this work, we employ first-principles calculations to investigate the optical properties of boron nitride nanoribbons with reconstructed edges. We found that because of the presence of homopolar B-B and N-N bonds in the edges, such nanoribbons, unlike boron nitride nanotubes, absorb light and have non-null optical conductivity in the visible and infrared range. The stoichiometry and distribution of the homopolar bonds in the edges change the absorption, reflectance, refraction index, and optical conductivity of nanoribbons, which may allow the tuning of those properties. Regarding the absorption in the infrared and visible range, the nanoribbons with B excess are almost unaffected by the direction of light incidence. On the other hand, the direction of light incidence strongly affects the intensity of the absorption peaks of nanoribbons with N excess in the region. At ultraviolet and above non-cylindrical geometry of the ribbons with the homopolar bonds at the edges also lead to a dependence of the optical properties with the direction of light incidence.
Gonçalves JA, dos Santos OFP, Batista RJC, Azevedo S. First-principle investigation of silicon carbide nanosheets fluorination: Stability trends, electronic, optical and magnetic properties. Chemical Physics Letters [Internet]. 2022;787 :139266. Publisher's VersionAbstract
We employed first-principles calculations to investigate the fluorination of silicon carbide nanosheets. We found that the Si atoms are the energetically favorable adsorption sites for F atoms in silicon carbide nanosheets in all studied cases. The strain caused by the fourfold coordinated Si atoms in the flat SiC nanosheet determines the relative position of the adsorbed F atoms: occupying nearest-neighbor Si sites if they bound sheet’s opposing sides or away from each other if they are on the same side of the sheet. The fluorinated nanosheets’ electronic and magnetic properties are weakly dependent on which side of the sheet the F atoms bind; however, they are strongly dependent on the relative distance between them. For F atoms adsorbed on nearest-neighbor Si sites, the system is a small gap p-type semiconductor with 1 μB per adsorbed atom. On the other hand, if F atoms do not occupy nearest-neighbor Si sites, the system is a metal with 1/2 μB per adsorbed atom. The adsorption of F atoms strongly affects the optical properties of SiC sheets inducing optical anisotropy regarding the direction of the incidence of light.