Apresentação

O nosso departamento congrega docente que atuam em diversas áreas de pesquisa, notadamente Ciências dos Materiais, Física Computacional, Astrofísica, Cosmologia e Gravitação, Big Bang, Matéria Escura, Energia Escura, Relatividade Geral e teorias gravitacionais alternativas.. Temos um curso de bacharelado em física com ênfases em ciências dos materiais e física básica e um curso de Licenciatura em Física. Atuamos nos cursos de Pós-graduação em Física de Materiais (FIMAT), Rede Temática em Engenharia de Materiais - REDEMAT, Mestrado Profissional em Estudo de Ciência (MPEC) e outros programas em colaboração com outros departamentos da UFOP. 

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Publicações Recentes do Departamento de Física

Zimdahl W, Fabris JC, Velten H, Herrera R. On (non-)dynamical dark energy. Physics of the Dark Universe [Internet]. 2020;30 :100681. Publisher's VersionAbstract
The current Universe is composed by a mixture of relativistic species, baryonic matter, dark matter and dark energy which evolve in a non-trivial way at perturbative level. An advanced description of the cosmological dynamics should include non-standard features beyond the simplistic approach idealized by the standard cosmology in which cosmic components do not interact, are adiabatic and dissipationless. We promote a full perturbative analysis of linear scalar perturbations of a non-interacting cosmological model containing baryons, dark matter (both pressureless) and a scalar field allowing for the presence of relative entropic perturbations between the three fluids. Assuming an effective scalar-field sound speed equal to one and neglecting anisotropic stresses we establish a new set of equations for the scalar cosmological perturbations. As a consequence of this new approach, we show that tiny departures from a constant scalar field equation of state wS=−1 damage structure formation in a non-acceptable manner. Hence, by strongly constraining wS our results provide compelling evidence in favor of the standard cosmological model and rule out a large class of dynamical dark energy models.
Cipreste MF, Mussel] W [da N, da Silva] J [B, de Marques] M [BF, Batista] RJ [C, Gastelois PL, de Macedo] W [AA, de Sousa] EM [B. A new theranostic system for bone disorders: Functionalized folate-MDP hydroxyapatite nanoparticles with radiolabeled copper-64. Materials Chemistry and Physics [Internet]. 2020 :123265. Publisher's VersionAbstract
Hydroxyapatite nanoparticles have been investigated as biological agents for the treatment and diagnosis of bone diseases due to their properties, providing high affinity to bone tissues and also due to the possibility to chemically modify the surfaces of these nanoparticles to provide active targeting to bone tumors or other bone disorders. In this work, synthetic hydroxyapatite nanoparticles and their surface modifications with folic and medronic acid were studied. Copper-64 was produced by neutron irradiation in a TRIGA MARK I nuclear reactor, and the functionalized nanoparticles radiolabeled with this radioisotope. The multi-technique characterization includes FTIR, PXRD, TGA, DSC, CHN, Zeta potential, XPS, SEM, TEM, and Gamma spectroscopy. Furthermore, the evaluation of the chemical interaction stability was through leaching tested for efficiency. The results indicate that folic and medronic acids can be covalently bonded to HA surface, producing a new material not yet described in the literature, been stably attached to hydroxyapatite nanoparticle surfaces, able to provide active targeting for bone disorders. The complexation of copper-64 provides high radiochemistry purity, although the specific activity must be improved.
Pacheco TS, Ludwig ZMC, Sant’Anna DR, Perpétuo GJ, Franco CJ, Paiva EC, Ghosh S. Growth and vibrational spectroscopy of K2LiyNixCo1-xSO42.6H2O (y=0.1;0.2;0.3;0.4) crystals. Vibrational Spectroscopy [Internet]. 2020;109 :103093. Publisher's VersionAbstract
The mixed crystals of the Tutton’s salt doped with Li following the empirical formula K2LiyNixCo1-x (SO4)2.6H2O, were synthesized from the slow evaporation of the solvent at constant temperature. The presence of K, S, Ni, Co and O elements in the studied crystalline structure was confirmed by EDS spectroscopy using a scanning electron microscope and their quantification including Li was carried out with the help of ICP-OES technique. Raman spectroscopy in the range 100−3600 cm−1, confirmed the presence of tetrahedral (SO4), octahedral complexes Ni(H2O)6, Co(H2O)6, and H2O molecules in the crystal structure. Our UV–vis studies have shown that the mixed crystals have good optical transparency in the ultraviolet (200−350 nm) and infrared (750−1000 nm) region. The direct and indirect optical energy gap of the synthesized crystals were determined from the Tauc’s plot. XRD diffractograms of the sample crystals do not show any specific changes due to the presence of Li ion in the crystalline network.
Ribeiro SP, Castro e Silva A, Dáttilo W, Reis AB, Góes-Neto A, Alcantara LCJ, Giovanetti M, Coura-vital W, Fernandes GW, Azevedo VAC. Severe airport sanitarian control could slow down the spreading of COVID-19 pandemics in Brazil. PeerJ [Internet]. 2020;8 :e9446. Publisher's VersionAbstract
Background We investigated a likely scenario of COVID-19 spreading in Brazil through the complex airport network of the country, for the 90 days after the first national occurrence of the disease. After the confirmation of the first imported cases, the lack of a proper airport entrance control resulted in the infection spreading in a manner directly proportional to the amount of flights reaching each city, following the first occurrence of the virus coming from abroad. Methodology We developed a Susceptible-Infected-Recovered model divided in a metapopulation structure, where cities with airports were demes connected by the number of flights. Subsequently, we further explored the role of the Manaus airport for a rapid entrance of the pandemic into indigenous territories situated in remote places of the Amazon region. Results The expansion of the SARS-CoV-2 virus between cities was fast, directly proportional to the city closeness centrality within the Brazilian air transportation network. There was a clear pattern in the expansion of the pandemic, with a stiff exponential expansion of cases for all the cities. The more a city showed closeness centrality, the greater was its vulnerability to SARS-CoV-2. Conclusions We discussed the weak pandemic control performance of Brazil in comparison with other tropical, developing countries, namely India and Nigeria. Finally, we proposed measures for containing virus spreading taking into consideration the scenario of high poverty.
da Almeida WAS, Sousa LRD, dos Santos Antunes A, de Azevedo AS, do Nascimento Aéa M, Amparo TR, de Souza GHB, dos Santos ODH, Andrade �ngela Lão, Cazati T, et al. Green Propolis: In Vitro Photoprotective and Photostability Studies of Single and Incorporated Extracts in a Sunscreen Formulation. Revista Brasileira de Farmacognosia [Internet]. 2020. Publisher's VersionAbstract
Propolis is a natural, non-toxic resin produced by honey bees that has been used for hundreds of years for its biological activities, such as antimicrobial, anti-inflammatory, anesthetic, cytostatic, and cariostatic properties. Currently, it is used in food, pharmaceutical, and cosmetic industries. The aim of this work was to evaluate the antioxidant activity, sun protection factor, and photostability of different hydroalcoholic extracts of green propolis. All extracts prepared presented high absorption in the UVB region. The extract of 70% green propolis (high temperature) was incorporated into Gel Permulen TR-1. This new formulation presented a higher value of sun protection factor. Besides that, the formulation developed with Gel Permulen TR-1 and the hydroalcoholic extract of 70% green propolis (high temperature) showed good photostability and it was safe to be applied on the skin according the HET-CAM test. These results indicated the potential of hydroalcoholic extracts of 70% green propolis (high temperature) for use in sunscreen.
Faria AMA, Miranda MA, Gonçalves GE, Bianchi RF, Bianchi AGC, Cuba C, Neves BRA, Pinto ES. Partially ordered porous structures on layer-by-layer polyaniline/poly(vinyl sulfate sodium) ultrathin films: Easy fabrication of robust submicroscopic patterning. Journal of Applied Polymer Science [Internet]. 2020;137 (17) :48597. Publisher's VersionAbstract
ABSTRACT The use of polyaniline (PANI) as a conductive material has steadily increased in recent years due to its interesting physicochemical properties, low manufacturing cost, and easy processing. This conductive material, associated with the diffraction properties of organized nanostructures in thin films, has excellent application potential in microelectronics and photonic devices. Initially, this work presents improvement routes for the breath figure method (a nanopatterning technique) in polystyrene (PS) films through the control of film deposition parameters and the presence of water in the polymer solution. Such improvements are then extended to the production of PANI nanostructures, in the form of pores, from patterned porous PS films. Consequently, PANI films with a partially ordered pore structure (mean pore diameter of  100 nm) are produced in a facile and easily scalable method. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48597.
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