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Initial study of structure of nanofiber textiles and the creation of its model
Havrlík, M.; Sveshnikov, Alexey
2015 - anglický
In this research, the structure of the fabrics was analyzed using an electron scanning microscope Tescan Maia 3. Two sets of the experiments have been carried out. In the first experiment the surface structure of the samples was studied. Photos created by SEM were analyzed using program Atlas and image editor GIMP. In this set of the experiments the initial parameters for the creation of a digital 2D model of a single layer have been determined (fiber size distribution, pore size and curvature of the fibers). In the second set of the experiments cross sections of nanofiber textiles were made in order to study the inner structure of the fabric. This information allows evaluation of the total number of 2D layers in the model and, thus, is very important for future creation of a 3D model of the fabric.
Klíčová slova:
polymer; SEM photography
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Initial study of structure of nanofiber textiles and the creation of its model
In this research, the structure of the fabrics was analyzed using an electron scanning microscope Tescan Maia 3. Two sets of the experiments have been carried out. In the first experiment the surface ...
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 - anglický
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.
Klíčová slova:
carbon-based materials; hardness; ion beam assisted deposition; a-C:N nanolayer
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 - anglický
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).
Klíčová slova:
SAOS-2 cells; cell movement; adhesion; stochastic computer simulations
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 - anglický
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.
Klíčová slova:
diamond; gas sensor; response; sensitivity
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 - anglický
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.
Klíčová slova:
nanocrystalline diamond; bacteria; Escherichia coli; anti-adhesive; CDC Bioreactor
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 - anglický
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
Klíčová slova:
nanocrystalline diamond; amorphous silicon; optical waveguides; FEM simulations
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 - anglický
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.
Klíčová slova:
5-nitroquinoline; azo-dyes; boron-doped diamond; boron concentration; voltammetry; reduction
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 ...
Studium tepelných procesů v systému Er:Li.sub.2./sub.O-Y.sub.2./sub.O.sub.3./sub.-P.sub.2./sub.O.sub.5./sub
Zemenová, Petra; Král, Robert; Nitsch, Karel; Cihlář, Antonín; Bystřický, Aleš
2015 - český
Tato práce se zabývá studiem vlivu velikosti částic práškových vzorků podchlazené taveniny Er:Li2O-Y2O3-P2O5 při tepelném zatížení na efekty skelné transformace a krystalizace. Dále se zabývá charakterizací mineralogického složení produktů krystalizace a stanovením materiálových vlastností připraveného skla. This work deals with a study of the particle size influence of the thermally treated Er:Li2O-Y2O3-P2O5 glassy powder samples on the effects of glass transformation and crystallization. Further, it presents the mineralogical composition of the crystallization products and material properties of prepared glasses.
Klíčová slova:
crystallization; system Er:Li.sub.2./sub.O-Y.sub.2./sub.O.sub.3./sub.-P.sub.2./sub.O.sub.5./sub.
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Studium tepelných procesů v systému Er:Li.sub.2./sub.O-Y.sub.2./sub.O.sub.3./sub.-P.sub.2./sub.O.sub.5./sub
Tato práce se zabývá studiem vlivu velikosti částic práškových vzorků podchlazené taveniny Er:Li2O-Y2O3-P2O5 při tepelném zatížení na efekty skelné transformace a krystalizace. Dále se zabývá ...
Boron-doped diamond electrodes in electroanalysis of reducible organic compounds
Vosáhlová, J.; Zavázalová, J.; Petrák, Václav; Schwarzová-Pecková, K.
2015 - anglický
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.
Klíčová slova:
5-nitroquinoline; azo-dyes; boron-doped diamond; boron concentration; voltammetry; reduction
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 - anglický
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.
Klíčová slova:
diamond nanoparticles; functionalized diamond surface; density functional theory; vibrational spectra; FTIR
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 ...
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