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Plasmon-mediated electrocatalytic activity of TiB2 towards water splitting
Buravets, V.; Zabelina, A.; Miliutina, E.; Popelková, Daniela; Henych, J.; Šťastný, Martin; Švorčík, V.; Lyutakov, O.
2021 - anglický
Environmental problems related to the economy based on fossil fuels are of paramount importance. However, transition to renewable energy sources is restrained by the availability of storage technologies. Electrochemistry is a widely recognized prominent tool to achieve this goal by converting renewable energy into the form of chemical bonds accessible further as fuels, such as hydrogen produced by water splitting. Crucial losses in such process are caused by the high overpotentials, required for water splitting as a hydrogen source. To achieve required efficiency of water splitting appropriate catalysts have to be found with the suitable combination of activity, stability and cost. Nano-structured, two-dimensional materials (2D) are attractive candidates due possessing many of the desired properties and highly tunable characteristics. Employing light allows additional degree of freedom to boost conventional photo-electrocatalysis, in particular plasmonmediated electrocatalysis. Enhancement of the catalytic activity can be increased even further if the catalytic system absorbs wide range of light spectrum. In this study, we combine plasmon-active Au grating with 2D flakes of TiB2, to perform plasmon-mediated water splitting half-reaction – hydrogen evolution.
Klíčová slova:
hydrogen; evolution, photo-electrocatalysis; plasmonics; 2D materials
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Plasmon-mediated electrocatalytic activity of TiB2 towards water splitting
Environmental problems related to the economy based on fossil fuels are of paramount importance. However, transition to renewable energy sources is restrained by the availability of storage ...
Lead soaps in paintings: symptoms and the role of humidity
Garrappa, Silvia; Švarcová, Silvie; Kočí, Eva; Hradilová, J.; Bezdička, Petr; Hradil, David
2020 - anglický
In this study, an overview of the symptoms of lead soaps reported in artworks in combination\nwith the study of the role of humidity on the formation of these degradation products have\nbeen thoroughly investigated. The use of optical microscopy, scanning electron microscopy\n(SEM) in combination with Fourier-transform infrared spectroscopy (FTIR) proved to be an\nefficient analytical approach to highlight both the saponified area of artworks’ samples and the\nformation of metal carboxylates within mock-up model systems. Optical microscopy revealed\nto be very useful for the first screening of samples embedded in resin, while SEM helped in\nthe detection and distribution of elements within the cross-sections. On the other hand, FTIR\nmicroscope proved to be a very powerful instrument for high-resolution point measurements\nperformed in the attenuated total reflection mode (ATR) mode with mercury-cadmium-telluride\n(MCT) detector, as well as for chemical imaging of larger area of both artworks’ and mock-up\nsamples performed in the ATR mode with focal plane arrays (FPA) detector. This study provides\nnew useful insights contributing to better understanding of factors affecting the paints‘ stability,\nwhich is neccesary for developing new efficient strategies for preservation and restoration of\nfatty-based painted artworks.
Klíčová slova:
lead soaps; paintings; oil; egg yolk; humidity
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Lead soaps in paintings: symptoms and the role of humidity
In this study, an overview of the symptoms of lead soaps reported in artworks in combination\nwith the study of the role of humidity on the formation of these degradation products have\nbeen ...
Historic paint investigation of the Gierczyn parish church painted decoration in the context of the mining history of the region
Svorová Pawełkowicz, Sylwia; Witkowski, M.; Svora, Petr; Wagner, B.
2020 - anglický
The painted decoration of the Gierczyn parish church situated in the Izera Mountains was studied in the context of the rich mining history of the region known for tin, copper, and cobalt ores extraction. Smalt and copper pigments identification is discussed in the context of possible provenance studies. The aim is to determine to what extent the decoration of the parish church in Gierczyn reflects the mining history of the region and to verify whether local materials could have been used. Historic paint investigation is supported by chemical analysis of pigments. Additionally, the paper presents results of research combining archival studies of copper and cobalt extraction, and smalt production in nearby Przecznica, and of the parish church which was the main temple for local miners.
Klíčová slova:
Przecznica (Querbach); Gierczyn (Giehren); mining history; smalt; copper pigments
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Historic paint investigation of the Gierczyn parish church painted decoration in the context of the mining history of the region
The painted decoration of the Gierczyn parish church situated in the Izera Mountains was studied in the context of the rich mining history of the region known for tin, copper, and cobalt ores ...
Characterization of hydrogenated silicon thin films and diode structures with integrated germanium nanoparticles
Stuchlík, J.; Fajgar, R.; Remeš, Z.; Kupčík, Jaroslav; Stuchlíková, H.
2018 - anglický
P-I-N diode structures based on the thin films of amorphous hydrogenated silicon (a-Si: H) deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique were prepared with embedded Si and Ge nanoparticles. The Reactive Laser Ablation (RLA) of germanium target was used to cover the intrinsic a-Si: H layer by Ge NPs under a low pressure of the silane. The RLA was performed using focused excimer ArF laser beam under SiH4 background atmosphere. Reaction between ablated Ge NPs and SiH4 led to formation of Ge NPs covered by thin GeSi: H layer. The deposited NPs were covered and stabilized by a-Si: H layer by PECVD. Those two deposition processes were alternated repeatedly. Volt-ampere characteristics of final diode structures were measured in dark and under illumination as well as their electroluminescence spectra.
Klíčová slova:
PECVD; a-Si: H; PIN diode; Ge; nanoparticles
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Characterization of hydrogenated silicon thin films and diode structures with integrated germanium nanoparticles
P-I-N diode structures based on the thin films of amorphous hydrogenated silicon (a-Si: H) deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique were prepared with embedded Si and ...
Combination of cobalt bis(dicarbollide) amino derivative and antibiotic effect on growth of staphylococcus epidermidis
Lokočová, K.; Vaňková, E.; Šícha, Václav; Masák, J.
2018 - anglický
Nosocomial infections are often caused by bacteria from the Staphylococcus genus. The clinically relevant representatives of this species are Staphylococcus epidermidis and Staphylococcus aureus which grow predominantly as surface-attached stable communities known as biofilms. Cells in these biofilms are often highly resistant to antibiotics. Therefore, new antimicrobial or antibiofilm substances are still being developed. In this study, we investigated the influence of cobalt bis(dicarbollide) or its amino derivatives, and antibiotics (erythromycin, tetracycline)-alone and in combination-to determine the antimicrobial activity and the inhibition of biofilm formation against three type strains of S. epidermidis. We used a microcultivation device to determine the minimum inhibitory concentrations and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay to determine the metabolic activity of the cells in biofilms. We observed the synergistic effect of cobalt bis(dicarbollide) and its amino derivatives with both the antibiotics on both the planktonic and biofilm cells.
Klíčová slova:
cobalt bis(dicarbollide); staphylococcus genus
Dokument je dostupný na externích webových stránkách.
Combination of cobalt bis(dicarbollide) amino derivative and antibiotic effect on growth of staphylococcus epidermidis
Nosocomial infections are often caused by bacteria from the Staphylococcus genus. The clinically relevant representatives of this species are Staphylococcus epidermidis and Staphylococcus aureus which ...
The deposition of germanium nanoparticles on hydrogenated amorphous silicon.
Stuchlík, J.; Volodin, V.A.; Shklyaev, A.A.; Stuchlikova, T.H.; Ledinsky, M.; Čermák, J.; Kupčík, Jaroslav; Fajgar, R.; Mortet, V.; More-Chevalier, J.; Ashcheulov, P.; Purkrt, A.; Remeš, Z.
2017 - anglický
We reveal the mechanism of Ge nanoparticles (NPs) formation on the surface of the hydrogenated amorphous silicon (a-Si:H) deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) on ITO and a on boron doped nanocrystalline diamond (BDD). The coating of Ge NPs on a-Si:H was performed by molecular beam epitaxy (MBE) at temperatures up to 450 degrees C. The Ge NPs were characterized by Raman spectroscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The nanocrystalline Ge particles are conglomerates of nanocrystals of size 10-15 nm and quantum dots (QDs) with size below 2 nm embedded in amorphous Ge phase. After coating with Ge NPs the a-Si:H thin films show better adhesion on BDD substrates then on ITO substrates.
Klíčová slova:
Ge nanoparticles; a-Si:H; PECVD; MBE
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
The deposition of germanium nanoparticles on hydrogenated amorphous silicon.
We reveal the mechanism of Ge nanoparticles (NPs) formation on the surface of the hydrogenated amorphous silicon (a-Si:H) deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) on ITO and a on ...
The origin issue of the head of John the Baptist from Tajov
Hradilová, J.; Bezúchová, E.; Hradil, David; Šídová, K.
2017 - anglický
The significant work of art, the Head of John the Baptist from Tajov, from the Museum of Central Slovakia in Banska Bystrica, which is probably part of the works of Niclaus Gerhaert von Leiden (1420/30 - 1475), was subject to conservation as well as detailed material analysis - first using non-invasive methods (radiography computer tomography, X-ray fluorescence), then laboratory analysis of taken samples (elemental and phase analysis, analysis of organic binders, dendrochronology, radiocarbon dating). The specific painting technique was described. Gilding of the head was performed without any ground only on brown preparatory layer for oil gilding (mixtion), however, the incarnates with an oily binder did contain a light dolomitic ground layer. The blood drops painting employed madder lake including sheep wool shearlings. The work consists of two parts - the head and the bowl, which was understood not to be original. Both parts are made from poplar wood. The results of the dating indicate that the head was created in the second half of the 15th century. The bowl could have been added later, but no later than the beginning of the 16th century. Its inclusion may have happened (albeit it is less probable) in the 17th century, but any period of time after that can be ruled out. The original colouring of the bowl was different the earth pigments of specific composition used in the ground layer imitated terracotta - a clay bowl. Based on the location of the existing hanging points the head was probably on display occasionally in a vertical position with a slight bottom view of 45 degrees.
Klíčová slova:
Niclaus Gerhaert von Leiden; non-invasive analysis; painting technique; radiocarbon dating
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
The origin issue of the head of John the Baptist from Tajov
The significant work of art, the Head of John the Baptist from Tajov, from the Museum of Central Slovakia in Banska Bystrica, which is probably part of the works of Niclaus Gerhaert von Leiden ...
Rebecca and Eliezer at the well a mysterious oil painting from the Historical Museum of the Slovak National Museum at the Bratislava Castle
Hradilová, J.; Kližanová, H.; Bezák, M.; Holcová, K.; Bezdička, Petr
2017 - anglický
Light microscopy, scanning electron microscopy and microanalysis, X-ray powder micro-diffraction, infrared micro-spectrometry as well as palaeontological analysis have been applied in order to solve the question of provenance of the oil-on-canvas painting Rebecca and Eliezer at the well. In addition to the finding of pigments important for the dating of the painting, as, e.g. Naples yellow (Pb2Sb2O7), or smalt, fossil nannoplankton was described in the carbonate-rich clay ground. It indicates the use of marine sediments of Eocene to Oligocene age. According to mineralogical and paleontological data this ground may be included among grounds used in Italy, particularly in the 17th century. The studied painting is today greatly altered due to extensive reworkings. Prussian blue was used to overpaint faded ultramarine and degraded smalt, which is visibly affected by saponification processes.
Klíčová slova:
Carlo Maratta/Maratti; materials research; painting technique; micropaleontology; clay-based grounds; saponification
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Rebecca and Eliezer at the well a mysterious oil painting from the Historical Museum of the Slovak National Museum at the Bratislava Castle
Light microscopy, scanning electron microscopy and microanalysis, X-ray powder micro-diffraction, infrared micro-spectrometry as well as palaeontological analysis have been applied in order to solve ...
New inorganic matrices for pultrusion technology II
Černý, Zbyněk
2016 - anglický
Development of inorganic matrix enabling rapid continuous preparation of thermally and chemically stable and fire resistant materials with controlled properties for nuclear industry.
Klíčová slova:
inorganic matrices
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
New inorganic matrices for pultrusion technology II
Development of inorganic matrix enabling rapid continuous preparation of thermally and chemically stable and fire resistant materials with controlled properties for nuclear industry.
12th International Conference Solid State Chemistry 2016 : Book of Abstracts
Lančok, Adriana
2016 - anglický
This book contains the programme and the abstracts of the conference. The conference programme covers presentations from scientists and users of scientific information working in similar areas, to estabilish platforms for collaborative reseach project initiatives.
Klíčová slova:
solid state chemistry
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
12th International Conference Solid State Chemistry 2016 : Book of Abstracts
This book contains the programme and the abstracts of the conference. The conference programme covers presentations from scientists and users of scientific information working in similar areas, to ...
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