National Repository of Grey Literature 6 records found  Search took 0.01 seconds. 
The Effect of temperature treatment TiO2 nanoparticles on antibacterial properties
Bytesnikova, Z. ; Valeckova, V. ; Švec, P. ; Richtera, L. ; Šmerková, K. ; Vítek, Petr ; Adam, V.
The synthesis of TiO2 nanoparticles (NPs) under various temperature treatments was described and TiO2 NPs was subsequently tested as an antibacterial agent. Scanning electron microscopy (SEM), Raman spectroscopy, Dynamic light scattering (DLS) were used to confirm structure of TiO2 NPs and detect differences between individual batches treated with different temperature. Antibacterial properties were tested on Escherichia coli (E. coli). TiO2 NPs as photocatalyst was incubated with bacterial cells under ambient light. Changes in temperature treatment can affect diameter size and crystal structure of TiO2 NPs as well as its antibacterial properties.
Nanouhlíkové materiály pro bioaplikace a detekci těžkých kovů =: Nanocarbon materials for bioapplications and heavy metals detection /
Bytešníková, Zuzana
The aim of this thesis was the synthesis of carbon nanomaterials and their composites for environmental applications, application as an antibacterial agent, and crop protection. As the basic constituent of all prepared nanomaterials, graphene oxide (GO) prepared by the modified Hummers method was successfully used. In order to improve the desired properties, the prepared GO was further reduced and modified with magnetic nanoparticles (MPs) and nanoparticles (NPs) of metals or metalloids to form composites. In the prepared nanocomposites, the synergistic effect of graphene oxide and nanoparticles was utilized. In the case of nanocomposite formed from reduced graphene oxide (rGO) and MPs, this composite was used to bind Se (IV) as a heavy metal from an aqueous medium. In addition, the advantage of this material was its reusability after a recovery in ethanol. To protect agricultural crops against Xanthomonas euvesicatoria (X. euvesicatoria), which causes the bacterial spot disease of tomato and pepper and considerable economic casualties, nanocomposite containing GO and copper and silver NPs was used. This nanocomposite was selected for application to tomato and pepper plants after previous microbiological tests in vitro.
HYDROGEN STORAGE PROPERTIES OF GRAPHENE OXIDE MATERIALS PREPARED BY DIFFERENT WAYS
Král, Lubomír ; Čermák, Jiří ; Bytesnikova, Z.
Graphene-based materials show unique properties. These single layered materials consist of 2D structure of carbon atoms, belong to the strongest known materials, that are very mechanically flexible, optically transparent and that are excellent electrical and thermal conductors. Recently, several studies on these types of materials have highlighted the potential of this material for hydrogen storage (HS) and raised new hopes for the development of an effective solid-state HS media. In the present paper, the structure and HS properties of graphene oxide (GO) and chemically reduced graphene oxide (rGO) produced by different procedures were studied. Hydrogen sorption characteristics of GO and rGO were measured using the Sieverts-type gas sorption analyzer PCT-Pro Setaram Instrumentation. The study of HS was carried out at temperature range from 198 K to 423 K under hydrogen pressure from 1x10(-4) to 4 MPa. \n\nFor the HS point of view, the advantage of GO or rGO compared to graphene, is the presence of multiple chemical groups that can be used for introducing modifiers and their superior spreading on the materials surface. The suitably functionalized GO or rGO materials could potentially exhibit outstanding HS properties.
HYDROGEN STORAGE PROPERTIES OF GRAPHENE OXIDE MATERIALS PREPARED BY DIFFERENT WAYS
Král, Lubomír ; Čermák, Jiří ; Bytesnikova, Z.
Graphene-based materials show unique properties. These single layered materials consist of 2D structure of carbon atoms, belong to the strongest known materials, that are very mechanically flexible, optically transparent and that are excellent electrical and thermal conductors. Recently, several studies on these types of materials have highlighted the potential of this material for hydrogen storage (HS) and raised new hopes for the development of an effective solid-state HS media. In the present paper, the structure and HS properties of graphene oxide (GO) and chemically reduced graphene oxide (rGO) produced by different procedures were studied. Hydrogen sorption characteristics of GO and rGO were measured using the Sieverts-type gas sorption analyzer PCT-Pro Setaram Instrumentation. The study of HS was carried out at temperature range from 198 K to 423 K under hydrogen pressure from 1x10(-4) to 4 MPa.
Fyzikální vlastnosti ovlivňující jakost rybího masa a produktů z ryb
Bytešníková, Zuzana
This thesis is based on physical properties of fish meat and fish products. Texture of fish meat is considered as one of the most perceived character. Major influence on the textural properties of fish meat has chemical composition of fish meat and fish meat structure. Fish products are changed during production by influence of low temperature during frozen storage and influence of high temperature during cooking. Changes in the textural properties of fish muscle caused during the autolytic process after slaughtering. The aim of the thesis was compared different methods for measurement textural properties of fish and fish products. Surimi sticks and pre-fried fish sticks were tested. Common carp (Cyprinus carpio), Rainbow trout (Oncorhynchus mykiss) and Tench (Tinca tinca) were chosen for testing by penetration test (penetration of the probe into the sample) and Warner-Bratzler shear test (sample cutting by Warner-Bratzler shear).
Texturní vlastnosti rybího masa a produktů z ryb
Bytešníková, Zuzana
The bachelor thesis is based on texture property of fish meat and fish products. Chemical composition and structure of fish meat has principal influence on texture of fish. Texture is influenced by other influence as diet, genetics, technology of farming, autolytic process and handling. Fish products are changed during production by influence of low temperature during frozen storage, influence of high temperature during cooking or change of pH. Sensory and instrumental methods are used for evaluation of texture property. Sensory evaluation is expensive, time-consuming, samples need heat treatment and sensory panel of professional. On the other hand instrumental methods are quick, easy reproducible, cheap despite the high cost of instruments. Although sensory methods are replaced by instrumental methods. Sensory methods are still gold standard of evaluation of texture property.

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