National Repository of Grey Literature 5 records found  Search took 0.00 seconds. 
Antibacterial electrospun membrane prepared from poly(vinylidene fluoride)-co-hexafluoropropylene with lauric acid monoacylglycerol
Zelenková, Jana ; Peer, Petra ; Pleva, P. ; Janalíková, M. ; Sedlaříková, J. ; Filip, Petr
The aim of this study was to prepare an antibacterial nanofibrous membrane using electrospinning technique. The nanofibrous membranes were spun from polymer solution of poly(vinylidne fluoride)-co-hexafluoropropylene (PVDF-co-HFP) dissolved in N,N´-dimethylformamide. Monoacylglycerol of lauric acid (MAG C12) was used as an antimicrobial agent at the concentrations ranging from 1 to 3 wt%. The impact of MAG C12 incorporation on the rheological, structural and antibacterial properties was investigated. The rheological tests of polymer solutions, as steady shear and oscillatory shear, proved that addition of MAG C12 changed marginally rheological quantities such as viscosity, elastic (storage) and viscous (loss) moduli. Measurement of mean nanofibres diameter indicated a slight decrease with increasing MAG C12 concentration. Antimicrobial activity of PVDF-co-HFP nanofibre membranes with incorporated MAG C12 against Gram-positive bacteria Staphylococcus aureus and Gram-negative Escherichia coli was studied. An antibacterial activity was revealed for the samples containing MAG C12 at all concentrations against Gram-positive bacteria Staphylococcus aureus by the disk diffusion method.
Encapsulation of active agents into natural polymers
Sedlaříková, J. ; Krejčí, J. ; Krhovská, D. ; Peer, Petra
Recently encapsulation has been intensively investigated to achieve a better absorbability and prolong efficiency of active agents. The aim of this work was to prepare the systems based on natural polymers zein and chitosan with active substances and observe the effect of individual components on the resultant physical and chemical properties of the encapsulation
Preparation and characterization of fibrous non-woven textile decorated by silver nanoparticles for water filtration
Peer, Petra ; Polášková, M. ; Mosnáček, J. ; Sedlařiková, J. ; Masař, M.
The environmentally friendly preparation of silver nanoparticles was proposed for the production of antibacterial non-woven textile used in water filtration. The silver nanoparticles were prepared by chemical reduction of silver nitrate using two environmentally friendly reducing agents, such as fructose or ascorbic acid. For comparison also commonly used reducing agent-sodium borohydride was used. The silver nanoparticles in various size and yield were produced by immersion of the plasma pre-treated polypropylene (PP) nonwoven textile in the colloidal solutions for different periods (35, 45 and 135 min). The morphology of the silver nanoparticles was characterized by SEM and EDX analysis. Additionally, the antibacterial activity of the silver decorated PP non-woven textile was evaluated by an agar diffusion test using both Gram-positive Staphylococcus Aureus and Gram-negative Escherichia coli. The results suggest that the type of the reducing agent has major effect both on the morphology of silver nanoparticles and the antibacterial activity.
Are financial returns and volatility multifractal at all?
Sedlaříková, Jana ; Krištoufek, Ladislav (advisor) ; Kraicová, Lucie (referee)
Over the last decades, multifractality has become a downright stylized fact in financial markets. However, its presence has not been adequately statistically proved. The main aim of this thesis is to contribute to the discussion by an ex- tensive statistical analysis of the problem. We investigate returns and volatility of the collection of the four stock indices employing the three popular methods: the GHE, the MF-DFA, and the MF-DMA method. By comparing the results of the original series to those for simulated monofractal series, we conclude that stock market returns as well as volatility exhibit a multifractal nature. Additionally, in order to understand the origin of underlying multifractality, we study vari- ous surrogate series. We found that a fat-tailed distribution significantly affects multifractality. On the other, we were not able to confirm the impact of time correlations as the results strongly depend on the applied model. JEL Classification F12, G02, G10, C12, C22, C49, C58 Keywords econophysics, multifractality, financial markets, Hurst exponent Author's e-mail jana.sedlarikova@gmail.com Supervisor's e-mail kristoufek@ies-prague.org
Income Elasticity of Money Demand: A Meta-Analysis
Sedlaříková, Jana ; Havránek, Tomáš (advisor) ; Šopov, Boril (referee)
The income elasticity of money demand represents an important economic variable which affects money demand function. Precise evaluation of money demand is important for central banking and for determining the transmission mechanism. Nevertheless, there is no general agreement on the exact structure of the function of money demand and income elasticity values neither in theoretical nor practical context. Many different economic theories concerning this field were developed by various economists during the 20th century. There was also a large amount of empirical research whose goal was to estimate the value of income elasticity based on real economic data. However, these studies are characterized by strong heterogeneity of the respective results. The method of meta-analysis is considered to be an effective statistical instrument that allows systematic evaluation of these inconsistent estimates. This method was applied to the dataset consisting of 985 empirical estimates from more than 70 primary studies. The publication selection bias was detected only in the case of using broad monetary aggregates. The resulting estimates adjusted for publication bias range from 0.784 for narrow monetary aggregates to 0.93 for the broadly defined money. In addition, meta- regression analysis revealed correlation...

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2 Sedlaříková, Jana
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