Influence of Skin Diseases on Fingerprint Recognition

There are many people who suffer from some of the skin diseases. These diseases have a strong influence on the process of fingerprint recognition. People with fingerprint diseases are unable to use fingerprint scanners, which is discriminating for them, since they are not allowed to use their fingerprints for the authentication purposes. First in this paper the various diseases, which might influence functionality of the fingerprint-based systems, are introduced, mainly from the medical point of view. This overview is followed by some examples of diseased finger fingerprints, acquired both from dactyloscopic card and electronic sensors. At the end of this paper the proposed fingerprint image enhancement algorithm is described

Surface-initiated mechano-ATRP as a convenient tool for tuning of bidisperse magnetorheological suspensions toward extreme kinetic stability

A concept initially intended for mechanically controlled atom transfer radical polymerization (hereinafter referred to as "mechano-ATRP") was extended in order to modify magnetic nanoparticles (NPs) with poly(methyl acrylate) (PMA) grafts, resulting in NPs@PMA hybrids which served as efficient additives in magnetorheological (MR) suspensions. In a novel procedure, magnetic NPs with an ATRP initiator anchored on their surfaces were added into a mechano-ATRP mixture, bringing about surface-initiated growth of the PMA chains after exposure to ultrasonication (35 kHz, 45 degrees C). The reaction proceeded with low concentration (at hundreds of "ppm") of the CuBr2 catalyst, thereby providing the PMA chains with low dispersity of molar masses and high monomer conversions. Investigation was conducted as to the effect of hexagonal micro-ZnO and cubic-phase BaTiO3 piezoelectric transducers on the feasibility of the process. The presence of PMA on the surfaces of NPs@PMA hybrids was proven by infra-red spectroscopy, as well as thermal and magnetization analyses. The NPs@PMA hybrids were subsequently applied as additives to fabricate a bidisperse MR suspension, in which they unexpectedly enhanced accessible shear stress and yield stress values by up to similar to 840 Pa under a magnetic field (of up to 432 kA m(-1)). Notably, the MR suspension supplemented with the NPs@PMA hybrids synthesized by mechano-ATRP exhibited no sign of sedimentation when left undisturbed for 2 days, although sedimentation of the reference sample occurred within a few hours. Such enhancements were attributed to the effects of friction, formation of a 3D gel-like network and the reduced density of the NPs@PMA hybrids.Ministry of Education, Youth and Sports of the Czech RepublicMinistry of Education, Youth & Sports - Czech Republic [RP/CPS/2020/006]; National Scholarship Programme of the Slovak Republic - Ministry of Education, Science, Research and Sport of the Slovak Republic [27926]; Integrated Infrastructure Operational Programme - ERDF [313021T081]; [VEGA 2/0129/19]; [APVV-19-0338]Slovenská Akadémia Vied, SAV: 313021T081; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Ministerstvo školstva, vedy, výskumu a športu Slovenskej republiky: 27926; Vedecká Grantová Agentúra MŠVVaŠ SR a SAV, VEGA: 2/0129/19, APVV-19-0338; European Regional Development Fund, ERD