An available open-source vein recognition framework

An available recognition toolkit is one of the basic requirements for conducting research in finger- and hand vein recognition. Currently, there is only one comprehensive, open-source, software package available, which includes a full finger vein recognition toolkit. We present a novel, full fledged vein recognition software framework implemented in MATLAB. Our PLUS OpenVein software package contains various well-established and state-of-the-art vein enhancement, feature extraction and comparison schemes. Moreover, it contains tools to evaluate the recognition performance and provides functions to perform feature- and score-level fusion. It is fully open source and available free of charge for research and non-commercial purposes. This vein recognition framework has already been used in several papers and can be a valuable tool for other researchers working in vein recognition.(VLID)460226

Porphyrin-nanoclay photosensitizers for visible light induced oxidation of phenol in aqueous media

A new type of hybrid photosensitizer (Po-C30B) was obtained by efficient adsorption of a 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (Po) by Cloisite 30B (C30B)-a monotallow bis(hydroxyethyl)ammonium-modified montmorillonite clay-from acidic solution in methanol. Structural and spectroscopic properties of Po-nanoclay photosensitizer were determined using X-ray diffraction, laser scanning fluorescence confocal microscopy, and electronic absorption/emission spectroscopies. Po is present not only at the surface of the nanoclay but also in the interior of the Po-C30B hybrid material. The obtained material was found to be an efficient photosensitizer for the oxidation of phenol in aqueous solution under irradiation with the visible light (λ > 470 nm). The mechanism and the quantum yield of that process were shown to be strongly pH-dependent. They were controlled by the acid-base equilibria of porphyrin associated with imine N-protonation as well as by the ionization of the phenol molecule. The quantitative information regarding these dependencies was obtained. The values of K3 and K4 acid-base equilibrium constants were determined (pK3 = 5.88 and pK4 = 2.46) from the absorption spectra recorded during acid-base titration and using an evolutionary factor analysis with the mathematical model including dicationic (H2Po2+), monocationic (HPo+), and neutral (Po) porphyrin forms. They were used to evaluate the importance of these forms in singlet oxygen generation by Po-C30B under defined pH conditions. Moreover, the hybrid photosensitizer can be used repeatedly, which makes it possible to use it in industrial applications