Od 3D počítačového modelování k realitě a zpět

Technologický pokrok neustále zrychluje a v jeho popředí se hřejí technologie spojené s 3D počítačovým modelováním, jako třeba 3D tisk, skenování a technologie spojené s virtuálně rozšířenou realitou. Tato práce dává nahlédnout za závoj tajemna, jež tyto technologie tak často obklopuje. Cílem je nabídnout krátký pohled na každou ze zmíněných oblastí. Čtenář bude mít možnost na vše nahlédnout z pohledu praktického, teoretického i trochu ajťáckého. To vše v naději, že se podaří tyto tři tak často vzdálené náhledy přivést blíž jak k sobě vzájemně, tak ke čtenáři.Technological advancements are faster than ever and on the frontier are applications and mechanisms entwined with 3D computer aided modelling, such as 3D printing, scan- ning and extended reality technologies. This work gives a peek behind the veil of mystery surrounding these technologies. We aim to give a brief look into each of the mentioned areas and let the reader experience them practically, mathematically and algorithmically in hope to bring these three so often separated views closer together and to the reader. 1Department of Mathematics EducationKatedra didaktiky matematikyMatematicko-fyzikální fakultaFaculty of Mathematics and Physic

Communication of molecular fluorophores with other photoluminescence centres in carbon dots

The establishment of structure-photoluminescence (PL) relationships remains an ultimate challenge in the field of carbon dots (CDs). It is now commonly understood that various structural domains may evolve during the preparation of CDs; nonetheless, we are still far from capturing the specific features that determine the overall PL of CDs. Although the core, surface and molecular states are usually considered the three main sources of PL, it is not known to which extent they interact and/or affect one another. Expectedly, the communication between the different PL centres depends on the mutual arrangement and the type of linking. To gain insights into such a communication, time-dependent density functional theory (TD-DFT) calculations were performed for several (N-doped/O-functionalized) polyaromatic hydrocarbons (PAHs) as representative models for the core/surfaces PL states and the prototypical molecular fluorophore (MF) 5-oxo-1,2,3,5-tetrahydroimidazo-[1,2-α]-pyridine-7-carboxylic acid (IPCA), considering different interaction modes, namely hydrogen bonded and stacked complexes as well as covalently bonded and fused structures. Our results revealed that each of the studied arrangements in some way supported the communication between the PL centres. The deactivation pathways typically involve multiple charge and energy transfer events that can promote the formation of charge separated states and/or lead to the activation of other PL centres in CDs. Depending on the arrangement, the doping pattern and surface functionalization, both the CD core and the MF can act as an electron donor or acceptor, which could help to design CDs with desirable hole–electron surface/core characteristics.Web of Science1584032402

Graphene nanobeacons with high-affinity pockets for combined, selective, and effective decontamination and reagentless detection of heavy metals

Access to clean water for drinking, sanitation, and irrigation is a major sustainable development goal of the United Nations. Thus, technologies for cleaning water and quality-monitoring must become widely accessible and of low-cost, while being effective, selective, sustainable, and eco-friendly. To meet this challenge, hetero-bifunctional nanographene fluorescent beacons with high-affinity pockets for heavy metals are developed, offering top-rated and selective adsorption for cadmium and lead, reaching 870 and 450 mg g(-1), respectively. The heterobifunctional and multidentate pockets also operate as selective gates for fluorescence signal regulation with sub-nanomolar sensitivity (0.1 and 0.2 nm for Pb2+ and Cd2+, respectively), due to binding affinities as low as those of antigen-antibody interactions. Importantly, the acid-proof nanographenes can be fully regenerated and reused. Their broad visible-light absorption offers an additional mode for water-quality monitoring based on ultra-low cost and user-friendly reagentless paper detection with the naked-eye at a limit of detection of 1 and 10 ppb for Pb2+ and Cd2+ ions, respectively. This work shows that photoactive nanomaterials, densely-functionalized with strong, yet selective ligands for targeted contaminants, can successfully combine features such as excellent adsorption, reusability, and sensing capabilities, in a way to extend the material's applicability, its life-cycle, and value-for-money.Web of Science1833art. no. 220100

XXV. mezinárodní kolokvium o regionálních vědách

Title in English: 25th International Colloquium on Regional Sciences: Conference proceedings The conference proceedings consists of papers presented at the 25th International Colloquium on Regional Sciences that was organized by Department of Regional Economics and Administration FEA MU. It contains 57 articles arranged by topic. The individual articles deal with e.g. socioeconomic disparities among regions, regional policy, territory attractiveness, tourism, or regional public administration

XXIV. mezinárodní kolokvium o regionálních vědách

Title in English: 24th International Colloquium on Regional Sciences: Conference proceedings. The conference proceedings consists of papers presented at the 24rd International Colloquium on Regional Sciences that was organized by Department of Regional Economics and Administration FEA MU. It contains 79 articles arranged by topic. The individual articles deal with e.g. socioeconomic disparities among regions, regional policy, territory attractiveness, tourism or regional public administration

The seniors in the prison sentence

Bakalářská práce je zaměřena na problematiku seniorů ve výkonu trestu odnětí svobody v porovnání s ostatními vězni. Teoretická část je věnována systému vězeňství jak v České republice, tak i v celém světě. Praktická část srovnává odlišnosti režimu, života, životní úrovně, zacházení, pracovních povinností a využití volného času trvale pracovně nezařaditelných vězňů (seniorů) oproti ostatním vězňům. Cílem této práce je prokázat tyto odlišnosti a zdůvodnit fakt, že by senioři ve výkonu trestu odnětí svobody měli mít jisté úlevy na rozdíl od ostatních vězňů.The bachelor thesis is focused on the seniors' issues during the imprisonment in comparison with other prisoners. The theoretical part is focused on the system of prisons, the prisons themselves not only in the Czech Republic but in the whole world. The practical part is dedicated to comparisons of differences between permanently unclassified prisoners (seniors) and other prisoners in the way of the regimes, the lives, the lifestyles, treatment, work duties and the utilization of the leisure time. The aim of this thesis is to prove these differences and to justify the fact of the senior prisoners relieves compared to other prisoners.Katedra věd o výchověDokončená práce s úspěšnou obhajobo

Inversion

Department of Mathematics EducationKatedra didaktiky matematikyMatematicko-fyzikální fakultaFaculty of Mathematics and Physic

From computer 3D modelling to reality and back

Technological advancements are faster than ever and on the frontier are applications and mechanisms entwined with 3D computer aided modelling, such as 3D printing, scan- ning and extended reality technologies. This work gives a peek behind the veil of mystery surrounding these technologies. We aim to give a brief look into each of the mentioned areas and let the reader experience them practically, mathematically and algorithmically in hope to bring these three so often separated views closer together and to the reader.

Unveiling the true band gap of fluorographene and its origins by teaming theory and experiment

Fluorographene is a fully fluorinated derivative of graphene. Unlike graphene, fluorographene is a wide gap semiconductor/insulator that holds great potential for applications requiring two-dimensional dielectric nano materials. Despite growing interest and a well-defined structure, the basic questions of fluorographene's band gap nature and value remain a conundrum. Here, we resolve this long-standing issue, demonstrating a direct optical band gap at 5.75 eV by means of diffuse reflectance spectroscopy. The nature of the band gap and the factors contributing to earlier controversies are explained by combining spectroscopic methods, ab initio calculations based on the finite momentum Bethe-Salpeter equation, and structural characterization via x-ray diffraction and Raman scattering. Ab initio calculations complement the experimental results by showing an excitonic peak at 5.65 eV of a Frenkel exciton bound to a single atom. The calculations also reveal that the absorption bands at lower energies arise from the presence of fluorine vacancies in the material, which explains earlier controversies in the literature about the band gap of fluorographene.Web of Science587art. no. 15283

Carbon dots detect water-to-ice phase transition and act as alcohol sensors via fluorescence turn-off/on mechanism

Highly fluorescent carbon nanoparticles called carbon dots (CDs) have been the focus of intense research due to their simple chemical synthesis, nontoxic nature, and broad application potential including optoelectronics, photocatalysis, biomedicine, and energy-related technologies. Although a detailed elucidation of the mechanism of their photoluminescence (PL) remains an unmet challenge, the CDs exhibit robust, reproducible, and environment-sensitive PL signals, enabling us to monitor selected chemical phenomena including phase transitions or detection of ultralow concentrations of molecular species in solution. Herein, we report the PL turn-off/on behavior of aqueous CDs allowing the reversible monitoring of the water-ice phase transition. The bright PL attributable to molecular fluorophores present on the CD surface was quenched by changing the liquid aqueous environment to solid phase (ice). Based on light-induced electron paramagnetic resonance (LEPR) measurements and density functional theory (DFT) calculations, the proposed kinetic model assuming the presence of charge-separated trap states rationalized the observed sensitivity of PL lifetimes to the environment. Importantly, the PL quenching induced by freezing could be suppressed by adding a small amount of alcohols. This was attributed to a high tendency of alcohol to increase its concentration at the CD/solvent interface, as revealed by all-atom molecular dynamics simulations. Based on this behavior, a fluorescence "turn-on" alcohol sensor for exhaled breath condensate (EBC) analysis has been developed. This provided an easy method to detect alcohols among other common interferents in EBC with a low detection limit (100 ppm), which has a potential to become an inexpensive and noninvasive clinically useful diagnostic tool for early stage lung cancer screening.Web of Science1546593658