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Hipersuperfícies conformemente euclidianas com curvatura média ou escalar constante
(Universidade Federal de São Carlos, 2016-11-10) Rei Filho, Carlos Gonçalves do; Figueiredo Junior, Ruy Tojeiro de; https://lattes.cnpq.br/9930999514347198; https://lattes.cnpq.br/5461170290751462
In this work we study conformally flat hypersurfaces f: M3 ^ Q4(c) with three distinct principal curvatures in a space form with constant sectional curvature c, under the assumption that either its mean curvature H or its scalar curvature S is constant. In case H is constant, first we extend to any c G R a theorem due to Defever when c = 0 and show that there is no such hypersurface if H = 0. Our main results are for the minimal case H = 0. If c = 0, we prove that f (M3) is an open subset of a generalized cone over a Clifford torus in an umbilical hypersurface Q4(c) C Q4(c), c > 0, with c > c if c > 0. For c = 0, we show that, besides the cone over the Clifford torus in S3 C R4, there exists precisely a one-parameter family of (congruence classes of) minimal isometric immersions f: M3 ^ R4 with three distinct principal curvatures of simply-connected conformally flat Riemannian manifolds. Assuming S to be constant, we only study the case c = 0. We prove that f (M3) is an open subset of a cylinder over a surface of nonzero constant Gauss curvature in R3.
Desenvolvimento de biossensor óptico para detecção de microrganismos patogênicos
(Universidade Federal de São Carlos, 2016-11-10) Thomazini, Bruno da Silva; Pizzolitto, Elisabeth Loshchagin; https://lattes.cnpq.br/3057012628845658; Moreira, Fernando Manuel Araújo; https://lattes.cnpq.br/1809254923092721; https://lattes.cnpq.br/5340055133029312
Infections caused by super-resistant microorganisms represent a major clinical and fiscal burden as a global problem. In addition, microorganisms are responsible for the deterioration of foods that, if consumed, can cause great harm to consumer health. For this reason, there is a need for constant monitoring both in the health area and in industrial processes, in order to prevent infections from occurring. Conventional methods for detecting micro-organisms are based on specific biological and biochemical identification. Although these methods are sensitive, inexpensive, and provide quantitative and qualitative information regarding the nature of the microorganism, they are restricted because they require relatively long time and require initial sample treatment for pathogens at low concentrations. The use of peptides in the detection of pathogenic microorganisms has been the subject of studies since it allows a precise and rapid detection. Peptides are known antimicrobial components used for a long time in the fight against infections caused by pathogens. Previous studies have demonstrated that the polycerradin peptide can be used in the development of sensors, since its antimicrobial action inhibits the luminescence of microorganisms due to cell death. The light signals from the antimicrobial action of this peptide against the microorganism were analyzed for the microorganisms Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Shigela sonnei, Furasim subglutinans, Colletotrichium gloeosporioides e Candida albicans. The spectra obtained through the data, which were collected by photoluminescence spectroscopy, showed that there was suppression of the luminescence around λ = 700-750 nm, when the lipopeptide extract (ELP) was added in all evaluated microorganisms. Thus, it was possible to determine the antimicrobial action of this peptide against the microorganisms studied, as well as the presence of these microorganisms through its emission spectrum. This technique was applied in the development and construction of an optical sensor, using materials of low cost, for use in the monitoring and identification of pathogenic microorganisms in several areas, such as health and food industry.
Uma abordagem híbrida baseada em Projeções sobre Conjuntos Convexos para Super-Resolução espacial e espectral
(Universidade Federal de São Carlos, 2016-11-10) Cunha, Bruno Aguilar; Homem, Murillo Rodrigo Petrucelli; https://lattes.cnpq.br/4099700446922080; https://lattes.cnpq.br/4204770612938184
This work proposes both a study and a development of an algorithm for super-resolution of digital images using projections onto convex sets. The method is based on a classic algorithm for spatial super-resolution which considering the subpixel information present in a set of lower resolution images, generate an image of higher resolution and better visual quality. We propose the incorporation of a new restriction based on the Richardson-Lucy algorithm in order to restore and recover part of the spatial frequencies lost during the degradation and decimation process of the high resolution images. In this way the algorithm provides a hybrid approach based on projections onto convex sets which is capable of promoting both the spatial and spectral image super-resolution. The proposed approach was compared with the original algorithm from Sezan and Tekalp and later with a method based on a robust framework that is considered nowadays one of the most effective methods for super-resolution. The results, considering both the visual and the mean square error analysis, demonstrate that the proposed method has great potential promoting increased visual quality over the images studied.