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Study of bioactive compounds of fennel
Mierna, Jana ; Skoumalová, Petra (referee) ; Veselá, Mária (advisor)
The master´s thesis is focused on the study of biologically active compounds of fennel. The theoretical part describes basic characteristics of fennel and its chemical composition, further specifies plant´s biological active substances and antioxidants, also describes extraction techniques for obtaining these bioactive compounds, methods of their determination and verification of antimicrobial effect. In the experimental part were spectrophotometrically determined contents of polyphenols and flavonoids in the prepared extracts of fennel tea, whole and crush spice. On the basis of extraction curves, antioxidant activity and potential antimicrobial activity against the selected microorganisms Bacillus subtilis, Bacillus cereus, Serratia marcescens a Micrococcus luteus was determined in the samples with the highest values of the given bioactive substances. Among the all monitored extracts, the inhibitory effect was showed only by an aqueous extract of the fennel tea against the bacterial strain of Micrococcus luteus.
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Influence of surface electrodes on the ozone generation in the dielectric barrier discharge.
Mierna, Jana ; Dzik, Petr (referee) ; Mazánková, Věra (advisor)
The bachelor´s thesis is focused on the study of influence of adsorbed gases on the electrode surface on ozone generation in dielectric barrier discharge. The theoretical part describes some basic properties and applications of ozone, methods of its generation, determination and interaction with the solid surfaces. In the experimental part was studied formation of ozone by the recombination of molecules and atoms of oxygen on the wall of electrodes and also its destruction caused by the reaction with particles present in closed ozoniser without discharge. Ozone was generated in cylindrical configuration system of electrodes made of staniless steel and alumina ceramics as dielectric material. Several series of experiments were measured by using various operating gases (oxygen; oxygen and argon; oxygen and nitrogen). It was also examined the decrease of generated ozone concentration in long-term operation by using pure oxygen of 99,999 90 % as a feeding gas. The resulting ozone concentration for given reaction time of individual measurements was determined by the method of absorption spectrometry.
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Study of bioactive compounds of fennel
Mierna, Jana ; Skoumalová, Petra (referee) ; Veselá, Mária (advisor)
The master´s thesis is focused on the study of biologically active compounds of fennel. The theoretical part describes basic characteristics of fennel and its chemical composition, further specifies plant´s biological active substances and antioxidants, also describes extraction techniques for obtaining these bioactive compounds, methods of their determination and verification of antimicrobial effect. In the experimental part were spectrophotometrically determined contents of polyphenols and flavonoids in the prepared extracts of fennel tea, whole and crush spice. On the basis of extraction curves, antioxidant activity and potential antimicrobial activity against the selected microorganisms Bacillus subtilis, Bacillus cereus, Serratia marcescens a Micrococcus luteus was determined in the samples with the highest values of the given bioactive substances. Among the all monitored extracts, the inhibitory effect was showed only by an aqueous extract of the fennel tea against the bacterial strain of Micrococcus luteus.
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Influence of surface electrodes on the ozone generation in the dielectric barrier discharge.
Mierna, Jana ; Dzik, Petr (referee) ; Mazánková, Věra (advisor)
The bachelor´s thesis is focused on the study of influence of adsorbed gases on the electrode surface on ozone generation in dielectric barrier discharge. The theoretical part describes some basic properties and applications of ozone, methods of its generation, determination and interaction with the solid surfaces. In the experimental part was studied formation of ozone by the recombination of molecules and atoms of oxygen on the wall of electrodes and also its destruction caused by the reaction with particles present in closed ozoniser without discharge. Ozone was generated in cylindrical configuration system of electrodes made of staniless steel and alumina ceramics as dielectric material. Several series of experiments were measured by using various operating gases (oxygen; oxygen and argon; oxygen and nitrogen). It was also examined the decrease of generated ozone concentration in long-term operation by using pure oxygen of 99,999 90 % as a feeding gas. The resulting ozone concentration for given reaction time of individual measurements was determined by the method of absorption spectrometry.
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