Departamento de Matemática
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Recent Submissions
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Notes for a study on the genesis of research in mathematics education in Brazil: Specialization in mathematical modelling in guarapuava / PR
(Bolema - Mathematics Education Bulletin, 2020) [Resenha] -
Energy bands and Wannier functions of the fractional Kronig-Penney model
(Applied Mathematics and Computation, 2020) [Artigo]Energy bands and Wannier functions of the fractional Schrödinger equation with a periodic potential are calculated. The kinetic energy contains a Riesz derivative of order α, with 1 < α ≤ 2, and numerical results are ... -
Charge transfer in Pr-Doped cerium oxide: Experimental and theoretical investigations
(Materials Chemistry and Physics, 2020) [Artigo]In this study was synthesized cerium oxide (CeO2) doped with praseodymium (Pr) using a microwave-assisted hydrothermal method. The positions of the vacancies with respect to Ce3+/Ce4+ and the vacancy-like defects surrounded ... -
Experimental and theoretical interpretation of the order/disorder clusters in CeO2:La
(Applied Surface Science, 2020) [Artigo]A spectroscopic study of nanostructured lanthanum-doped cerium oxide samples showed that a mild decrease by 5.3% in the surface concentration of Ce(III) species and, a reduction by 0.2 eV in the so-called energy-gap (EF – ... -
Influence of Synthesis Time on the Morphology and Properties of CeO2 Nanoparticles: An Experimental-Theoretical Study
(Crystal Growth & Design, 2020) [Artigo]Here we combined experimental and theoretical results to correlate the morphological, optical, and electronic properties of cerium oxide (CeO2) prepared by a microwave-assisted hydrothermal method with varying synthesis ... -
Intra-octahedral distortion on lamellar potassium niobate K4Nb6O17: a periodic DFT study of structural, electronic and vibrational properties
(Physical Chemistry Chemical Physics, 2020) [Artigo]Structural, electronic and spectroscopic properties of the anhydrous K4Nb6O17 niobate were investigated in the bulk phase using periodic density functional theory (DFT) calculations with global hybrid (B3LYP) and also ... -
Energy bands and Wannier functions of the fractional Kronig-Penney model
(Applied Mathematics And Computation, 2020) [Artigo] -
Optimal power flow via interior-exterior method
(2007 Ieee Power Engineering Society General Meeting, Vols 1-10, 2007) [Trabalho apresentado em evento]This paper presents a new approach to the resolution of the Optimal Power Flow problem. In this approach the inequality constraints are treated by the Modified Barrier and Primal-Dual Logarithmic Barrier methods. The ... -
Structural and electronic properties of PbTiO3: Density functional theory applied to periodic models.
(Quimica Nova, 2005) [Artigo]STRUCTURAL AND ELECTRONIC PROPERTIES OF PbTiO3 : DENSITY FUNCTIONAL THEORY APPLIED TO PERIODIC MODELS. Calculations based on density functional theory at the 133LYP hybrid functional level applied to periodic models have ... -
Experimental (electrochemistry) and theoretical (ab initio and density functional theory) studies of hydrogen and sulfide adsorption on palladium (100) surface.
(Quimica Nova, 2001) [Artigo]The adsorption of H And S2- species on Pd (100) has been studied with ab initio, density-functional calculations and electrochemical methods. A cluster of five Pd atoms with a frozen geometry described the surface. The ... -
Oxidative dehydrogenation of ethylbenzene to styrene over the CoFe2O4-MCM-41 catalyst: Preferential adsorption on the O2-Fe3+O2- sites located at octahedral positions
(Catalysis Science and Technology, 2019) [Artigo]The present study describes the catalytic performance of cobalt ferrite supported on MCM-41 for the oxidative dehydrogenation of ethylbenzene. The catalytic activity of cobalt ferrite was compared with that of the traditional ... -
Effect of a resin-modified glass-ionomer with calcium on enamel demineralization inhibition: An in vitro study
(Brazilian Oral Research, 2019) [Artigo]We assessed the effect of a new coating material based on resin-modified glass-ionomer with calcium (Ca) in inhibiting the demineralization of underlying and adjacent areas surrounding caries-like lesions in enamel. The ... -
Proposal and Solution of a Mixed-Integer Nonlinear Optimization Model That Incorporates Future Preparedness for Project Portfolio Selection
(IEEE Transactions on Engineering Management, 2019) [Artigo]In the context of project management, the attention given to project portfolio management has increased in recent years. The use of mathematical programming for portfolio management is also on the rise, because it integrates ... -
A methodology to determine size and shape of plots for sugarcane plantation
(Scientia Agricola, 2019) [Artigo]Brazil is the largest sugarcane producer in the world and the leader in the production of sugar and ethanol. Although sugarcane has become an important factor in the Brazilian economy, cultivation has presented many issues, ... -
PARAMETRIZATION FOR A CLASS OF RAUZY FRACTALS
(Osaka Journal Of Mathematics, 2019) [Artigo]In this paper, we study a class of Rauzy fractals R-a given by the polynomial x(3) - ax(2) + x - 1 where a >= 2 is an integer. In particular, we give explicitly an automaton that generates the boundary of R-a and using an ... -
Interior/exterior-point methods with inertia correction strategy for solving optimal reactive power flow problems with discrete variables
(Annals of Operations Research, 2018) [Artigo]Interior/exterior-point methods have been widely used for solving Optimal Reactive Power Flow problems (ORPF). However, the utilization of such methods becomes difficult when transformer taps and/or capacitor/reactor banks ... -
A quantum-mechanical investigation of oxygen vacancies and copper doping in the orthorhombic CaSnO3 perovskite
(Physical Chemistry Chemical Physics, 2018) [Artigo]In this study we explore the implications of oxygen vacancy formation and of copper doping in the orthorhombic CaSnO3 perovskite, by means of density functional theory, focusing on energetic and electronic properties. In ... -
Peirce's primary arithmetics: A brief presentation and some remarks on the translation of these manuscripts to Portuguese
(Bolema - Mathematics Education Bulletin, 2018) [Artigo]This paper aimsto present the five manuscripts of the so-called Peirce's Primary Arithmetics(Lydia Peirce's Primary Arithmetic; Primary Arithmetic (with suggestions to teachers); Peirce's Primary Arithmetic upon the ... -
Hydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical data
(Arabian Journal of Chemistry, 2018) [Artigo]In this paper, we report about hydrothermal synthesis, structural characterization and photocatalytic properties of beta-silver molybdate (β-Ag2MoO4) microcrystals obtained at different temperatures (100, 120, 140 and 160 ... -
Conducting behavior of crystalline a-PbO2 as revealed by DFT calculations
(Materials Research, 2018) [Artigo]PbO2 is one material that has recently emerged as potential transparent conducting oxide for applications in the modern opto-electronic industry. In this work the electronic structure of the a-PbO2 polymorph has been ...