No (412)
Number of found documents:
412
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Nanomechanical testing of an a-C:N nanolayer prepared by ion beam assisted deposition on Ti.sub.6./sub.Al.sub.4./sub.V alloy
Vlčák, P.; Šepitka, J.; Horaždovský, T.; Jirka, Ivan; Gregora, Ivan; Němec, M.
2015 - English
We applied ion beam assisted deposition for preparing a-C:N nanolayers on Ti6Al4V alloy. A Hysitron TI 950 TriboIndenter (TM) nanomechanical test instrument was used to assess the depth profiles of the mechanical properties on modified titanium substrates. Two methods were employed : a) quasistatic partial unload, and b) dynamic Continuous Measurement of X (CMX). The average nanoindentation hardness increased from HIT similar to 5GPa for a reference sample to HIT similar to 8.6 GPa for a sample coated by an a-C nanolayer, and to HIT similar to 11.5 GPa for a sample coated by an a-C:N nanolayer. The average storage modulus of the sample coated by a-C:N increased from E' similar to 130 GPa (reference sample) to E' similar to 155 GPa. The storage modulus of the sample coated by the a-C nanolayer was less than the storage modulus of the titanium substrate.
Keywords:
carbon-based materials; hardness; ion beam assisted deposition; a-C:N nanolayer
Available at various institutes of the ASCR
Nanomechanical testing of an a-C:N nanolayer prepared by ion beam assisted deposition on Ti.sub.6./sub.Al.sub.4./sub.V alloy
We applied ion beam assisted deposition for preparing a-C:N nanolayers on Ti6Al4V alloy. A Hysitron TI 950 TriboIndenter (TM) nanomechanical test instrument was used to assess the depth profiles of ...
Computational study of cellular assembly on hydrophobic/hydrophilic micro-patterns
Ukraintsev, Egor; Brož, A.; Kalbáčová, M.H.; Kromka, Alexander; Rezek, Bohuslav
2015 - English
We develop simple onedimensional stochastic model of cell behavior on chemically patterned surfaces that is based on three key parameters: speed of cell movement (motility) across substrate, probability of cell adhesion to substrate, and probability of cell division on substrate when adhered on substrate. Amount of adhered cells on hydrophobic and hydrophilic regions is calculated as function of time (number of cycles up to 2000). The model is correlated with in-vitro data obtained within 48 h in real time. We show that this simple stochastic model with the three parameters (where cell motility is the most important one) can describe with high accuracy the experimental data and thereby explain the observed preferential cell assembly on hydrophilic/hydrophobic micro-patterns (up to 200 um width).
Keywords:
SAOS-2 cells; cell movement; adhesion; stochastic computer simulations
Available at various institutes of the ASCR
Computational study of cellular assembly on hydrophobic/hydrophilic micro-patterns
We develop simple onedimensional stochastic model of cell behavior on chemically patterned surfaces that is based on three key parameters: speed of cell movement (motility) across substrate, ...
Hydrogen-terminated diamond surface as gas sensing layer working at room temperature
Davydova, Marina; Kulha, P.; Babchenko, Oleg; Kromka, Alexander
2015 - English
Effect of fluorine- and hydrogen-terminated diamond surface on the gas sensing properties at room temperature was investigated. The gas sensing properties diamond-based sensor were measured by the changes of electrical resistance to various volatile organic compounds (C6H6, C3H6O, isopropylalcohol) and relative humidity. The comparative sensing performance of hydrogenated diamond surface shows improvement in sensitivity toward benzene, acetone, isopropylalcohol and humid air in contrast to fluorinated diamond surface, where the surface conductivity was suppressed.
Keywords:
diamond; gas sensor; response; sensitivity
Available at various institutes of the ASCR
Hydrogen-terminated diamond surface as gas sensing layer working at room temperature
Effect of fluorine- and hydrogen-terminated diamond surface on the gas sensing properties at room temperature was investigated. The gas sensing properties diamond-based sensor were measured by the ...
Growth of Escherichia coli on nanocrystalline diamond
Jurková, Blanka; Kozak, Halyna; Artemenko, Anna; Ukraintsev, Egor; Beranová, J.; Konopásek, I.; Kromka, Alexander
2015 - English
In this contribution, we compared the attachment of gram-negative model bacterium Escherichia coli to\nuncoated glass and glass coated by hydrogenated and oxidized NCD films. For attachment experiments,\ncontinuous cultivation in commercially available CDC Bioreactor was used. Antibacterial tests indicated\nhigher attachment of gram-negative model bacterium Escherichia coli to NCD surface compared to uncoated\nglass. We assign this effect to higher roughness of NCD surface compared to glass. Bacterial cells preferred\nthe hydrophobic surface of hydrogenated NCD surface to hydrophilic oxidized NCD for their attachment.
Keywords:
nanocrystalline diamond; bacteria; Escherichia coli; anti-adhesive; CDC Bioreactor
Available at various institutes of the ASCR
Growth of Escherichia coli on nanocrystalline diamond
In this contribution, we compared the attachment of gram-negative model bacterium Escherichia coli to\nuncoated glass and glass coated by hydrogenated and oxidized NCD films. For attachment ...
Calculations of nanocrystalline diamond-covered waveguides based on amorphous silicon
Jirásek, Vít; Prajzler, Václav; Remeš, Zdeněk
2015 - English
Nanocrystalline diamond (NCD) coatings on planar waveguides (WG) in the IR region allow to design optical sensors sensitive to absorbers like proteins or other biomolecules. In this contribution, we present a 2D model of a multi-layer WG developed under FEM (finite element method) simulation software Comsol Multiphysics. The model is based on the modified wave equation solved in the frequency domain and includes optical absorption. It was found that for the single-mode WG working in the narrow region of 1550-2000 nm the silicon thickness must be 150-320 nm. It was found that in order to keep a reasonable signal attenuation, the NCD film must be prepared with the optical absorption coefficient lower than 10 cm-1, being a rather challenging task. Dependencies of the signal attenuation on the NCD film thickness, absorbing layer height, its absorption coefficient and exciting wavelengths are presented.\n
Keywords:
nanocrystalline diamond; amorphous silicon; optical waveguides; FEM simulations
Available at various institutes of the ASCR
Calculations of nanocrystalline diamond-covered waveguides based on amorphous silicon
Nanocrystalline diamond (NCD) coatings on planar waveguides (WG) in the IR region allow to design optical sensors sensitive to absorbers like proteins or other biomolecules. In this contribution, we ...
Boron-doped diamond electrodes in electroanalysis of reducible organic compounds
Vosáhlová, J.; Zavázalová, J.; Petrák, Václav; Schwarzová-Pecková, K.
2015 - English
Boron doped diamond (BDD) electrodes became a well-established tool in electroanalysis of oxidizable organic compounds, nevertheless their possibilities in electroanalysis of reducible compounds remain relatively unexploited. Thus, in this study the influence of the presence of oxygen, electrode pretreatment, and activation between individual scans for electroreduction of tartrazine and allura red (azo group), 5-nitroquinoline (nitro group and N-heterocycle), vanillin (aromatic aldehyde), and azidothymidine (azide group) using batch voltammetry was tested.
Keywords:
5-nitroquinoline; azo-dyes; boron-doped diamond; boron concentration; voltammetry; reduction
Available at various institutes of the ASCR
Boron-doped diamond electrodes in electroanalysis of reducible organic compounds
Boron doped diamond (BDD) electrodes became a well-established tool in electroanalysis of oxidizable organic compounds, nevertheless their possibilities in electroanalysis of reducible compounds ...
FLC-15: Challenges in polar self-assembling systems
Bubnov, Alexej; Glogarová, Milada
2015 - English
This is the Book of Abstracts for the 15th International Conference on Ferroelectric Liquid Crystals (FLC-15 conference) held in Prague on June 28 - July 3, 2015. The broadening of the field compared to the beginning of this biennial series in 1987 is expressed in the conference subtitle: Challenges in polar self-assembling systems. The continuous worldwide interest to this conference series is proving that it has still a respected position within the series of International/European conferences on liquid crystals covering all interdisciplinary field of the liquid crystal research. At the FLC-15 conference more than 130 participants from 25 countries all over the world will present 5 key-note lectures, 14 invited talks and selected 39 oral contributions. The number has been limited to keep the single session conference format as it is a tradition for the FLC conference series. About 90 posters were presented in two poster sessions. For your convenience, the FLC-15 conference program is presented in this book.
Keywords:
ferroelectric liquid crystals; polar liquid crystalline phases
Available at various institutes of the ASCR
FLC-15: Challenges in polar self-assembling systems
This is the Book of Abstracts for the 15th International Conference on Ferroelectric Liquid Crystals (FLC-15 conference) held in Prague on June 28 - July 3, 2015. The broadening of the field compared ...
Boron-doped diamond electrodes in electroanalysis of reducible organic compounds
Vosáhlová, J.; Zavázalová, J.; Petrák, Václav; Schwarzová-Pecková, K.
2015 - English
Boron doped diamond (BDD) electrodes became a well-established tool in electroanalysis of oxidizable organic compounds; nevertheless their possibilities in electroanalysis of reducible compounds remain relatively unexploited. Thus, in this study the influence of the presence of oxygen, electrode pretreatment, and activation between individual scans for electroreduction of tartrazine and allura red (azo group), 5-nitroquinoline (nitro group and N-heterocycle), vanillin (aromatic aldehyde), and azidothymidine (azide group) using batch voltammetry was tested.
Keywords:
5-nitroquinoline; azo-dyes; boron-doped diamond; boron concentration; voltammetry; reduction
Available at various institutes of the ASCR
Boron-doped diamond electrodes in electroanalysis of reducible organic compounds
Boron doped diamond (BDD) electrodes became a well-established tool in electroanalysis of oxidizable organic compounds; nevertheless their possibilities in electroanalysis of reducible compounds ...
Interpretation of the C=O band of modified diamond nanoparticles by means of DFT theory
Jirásek, Vít; Kozak, Halyna; Remeš, Zdeněk; Kromka, Alexander
2015 - English
Diamond nanoparticles (DNPs) are an interesting class of nanomaterials, which has many unique properties. Their applications in medicine and molecular biology have been mentioned. The DNPs were reviewed in sense of their surface chemistry and a range of analytic techniques was pointed out. The experimental analysis can be enhanced by theoretical models based on the first principles. An approach to theoretical analysis of infrared spectra was introduced. As an example, a part of FTIR spectra of the oxidized DNPs was interpreted by means of the DFT theory. The calculation of the C=O stretch vibrational frequencies of carboxylic and anhydride groups on certain model clusters enabled to explain the shift and splitting of the measured spectral bands.
Keywords:
diamond nanoparticles; functionalized diamond surface; density functional theory; vibrational spectra; FTIR
Available at various institutes of the ASCR
Interpretation of the C=O band of modified diamond nanoparticles by means of DFT theory
Diamond nanoparticles (DNPs) are an interesting class of nanomaterials, which has many unique properties. Their applications in medicine and molecular biology have been mentioned. The DNPs were ...
Verification of the use of pva based nanofiber textiles as a rehabilitation for the structures attack by wood decaying fungi
Rácová, Z.; Ryparová, Pavla; Wasserbauer, R.; Nežerka, V.; Tesárek, Pavel; Demo, Pavel
2014 - English
The presented paper is focused on the investigation of antifungal properties of nanofiber PVA-based textiles with incorporated copper and silver ions. In particular, the ability to prevent the growth of Dry rot fungus (Serpula lacrymans) was studied in laboratory conditions. For that purpose, the Petri dishes with malt agar were inoculated with square cut-outs of seed stocks, consequently covered by the nanofiber textiles and kept in an incubator at 28 degrees C. The fungal growth had been monitored and recorded at regular intervals for 28 days. The comparison of the individual treatments (PVA, PVA + Ag, PVA + Cu, PVA + Ag + Cu) is finally discussed.\n
Keywords:
nanofiber textiles; dry rot fungus; PVA; metal ions
Available at various institutes of the ASCR
Verification of the use of pva based nanofiber textiles as a rehabilitation for the structures attack by wood decaying fungi
The presented paper is focused on the investigation of antifungal properties of nanofiber PVA-based textiles with incorporated copper and silver ions. In particular, the ability to prevent the growth ...
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