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Microbiological hazards in HVAC systems
Musil, Zdeněk ; Charvát, Pavel (referee) ; Kolbábek, Antonín (advisor)
This bachelor thesis deals with microbiological hazards in HVAC systems, especially in air condition systems. There is noted the basic information from related fields. The same microbiological hazards are divided in health risk and in microbiological corrosion. In the last part of this thesis are mentioned possibilities of their elimination and recommendation for prefiguring of them.
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Study of sterilization effect of diaphragm discharge in liquids
Holíková, Lenka ; Slámová, Jitka (referee) ; Kozáková, Zdenka (advisor)
The main objective of this thesis is to study the sterilizing effect of diaphragm discharge in liquids. Sterilization is a process, which can eliminate all forms of life. Generally, sterilization is divided into physical and chemical methods. Plasma sterilization is ranked among physical methods although the action of chemical processes participates in the decontamination as well. Effects of UV radiation, free radicals and temperature are utilized in these methods. Fungi spores of Aspergillus niger F8189 and bacteria spores of Bacillus subtilis are selected as model organisms. Aspergillus niger microorganism is suitable for its resistance to changes in pH and it is viable in a wide range of pH values. Bacillus subtilis is chosen because of a good heat resistance. Diaphragm discharge is one of the possible types of electrical discharges in generated liquids. It is a low-temperature plasma, which is generated using a high DC voltage. In the created plasma streamers various physical and chemical processes rise. The chemical processes are mainly the generation of active species and particles that initiate subsequent chemical reactions and attack mould spores and bacteria in liquids. The physical processes include shock waves, strong electric field and ultraviolet radiation. Experiments were conducted in a reactor with separate cathode and anode space. In the dielectric barrier PET diaphragm with a pin-hole (initial diameter of 0.4 mm) was attached. Enlargement of the hole was observed as a result of degradation of material at the edge of holes due to the discharge. Degradation of spores was observed, depending on the time and on the input power. Other parameters measured were pH, conductivity and temperature. Experiments did not show any difference of discharge activity in the cathode and anode area. The main factor in the removal of spores Aspergillus niger was probably the temperature because no demonstrable effect of sterilization by the diaphragm discharge operation had been observed when heat resistant Bacillus subtilis was used. Also, it was made an attempt, which has been studied only the temperature effect of the fungi spores of Aspergillus niger. The samples were placed in a thermoregulator, where it was simulated the same temperature increase as at the discharge. The experiment had a similar course as an attempt at the discharge.
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Thermophilic microorganisms
Sůkalová, Kateřina ; Vránová, Dana (referee) ; Babák, Libor (advisor)
This bachelor’s thesis is focused on distribution thermophilic species from among microorganisms, characteristic important genera, in which these microorganisms we can find and detailed description choice species. There is described origin of thermal environment and locations of habitation thermophilic microorganisms with intention on geothermal areas, where is found the biggest number of these species. In consequence of thermal stability of enzymes these microorganisms are used in food industry, in waste treatment, in medicine and for their production of thermostabile enzymes.
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Degradation possibilities of synthetic macromolecular materials centred on biodegradations
Zichová, Miroslava ; Ondruška, Vladimír (referee) ; Babák, Libor (advisor)
This work deals with the degradation possibilities of synthetic macromolecular materials. Mechanical, chemical and chemo-physical degradation is described, but the work is focused on biodegradation. Polymer biodegradation is its decomposition by microorganisms. The aim of the work is to show the advantages of biodegradation and to arrange the knowledge acquired about the biodegradation of particular macromolecular materials. There is resumed the information about the degradation of polyurethanes as an exception among synthetic polymers, which are mostly resistant to biodegradation. Attention is also paid to biodegradable polymers.
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Methods for prolonging the shelf life of minced fish meat
KUBÍK, Michal
The initial part of this work sums up the methods of mechanical mincing of fish meat and food safety. The fish meat processing methods are described in detail and supplemented with the respective legislative. The primary factors affecting the quality and usability of the product are the changes caused by proteolysis and autolysis, the occurrence of microorganisms and biogenic amines. These processes are natural; they may only be delayed or reduced in intensity. Despite the possibility of using different preservatives, we need to pay attention to the basic hygienic and technological processes particularly in shortening their duration and storage conditions, especially the temperature. The major part of the research focuses on the possibility of using the enzyme preparation of SEA-i and its impact on the occurrence of biogenic amines, coliform bacteria and the total number of microorganisms in separated carp meat in smoking and liquid smoke treatment. Using SEA-i has proved to be a suitable means for preventing the development of biogenic amines. He was able to suppress the development of histamine below the detectable limit and the amount of putrescine decreased to 24 mg.kg-1 compared to the control group with the appearance of 89 mg.kg-1. For other biogenic amines has also demonstrated potent inhibitory effect. Its effect was also demonstrated in the total number of microorganisms.
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Charakterizace zátěže obyvatel malých sídel škodlivinami z ovzduší a znečištění ovzduší bioaerosoly: Znečištění ovzduší bioaerosoly
Státní zdravotní ústav, Praha ; Kvasničková, Simona ; Matějů, Ladislava ; Kazmarová, Helena ; Kotlík, Bohumil
Cílem dílčího úkolu II bylo vypracovat obecně použitelnou metodu 24 hodinových odběrů vzorků ovzduší pro měření výskytu bioaerosolů, zhodnotit výskyt bioaerosolů v blízkosti vybraných zemědělských zařízení, popsat sezónní kolísání výskytu bioaerosolů a vliv meteorologických parametrů a zhodnotit míru rizika výskytu bioaerosolů. Práce zahrnovala čtyři etapy řešení. V prvé etapě řešení byla provedena rešerše dosud známých faktů o vzorkování bioaerosolů / živých částic a zvolen typ vzorkovače. V druhé etapě řešení bylo provedeno sledování denních profilů výskytu bioaerosolů / živých částic v lokalitě, která nebyla zatížena zvýšeným výskytem živých částic z jakéhokoliv zdroje znečištění jako jsou např. kompostárny, čistírny odpadních vod, zemědělská živočišná výroba apod. Ve třetí a čtvrté etapě byl zjišťován vliv zdroje znečištění jako je drůbežárna a velkochov vepřů na výskyt bioaerosolů/ živých částic v jejich okolí. Zároveň byl sledován vliv některých mikroklimatických podmínek na výskyt diskutovaných živých částic. Jako doplnění hodnocení vlivu významného zemědělského objektu bylo provedeno i hodnocení pachové zátěže.
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The Luminars - a convolute of illuminational bodies
VODÁKOVÁ, Helena
The Diploma thesis introduces the luminars as the creative objects importing the light into our homes and effecting our mood. The objects are modeled of the slurry combined with glass. These are determined to the installation on the table, floor, wall and ceiling. For the shape I was inspired by MICROCOSM = a world of unicellular living being, before all by the protozoans. It is a world full of bizar structures and shapes. The simplicity and expediency of the protozoans offers the inexhaustible amount of ideas. Each of the objects has got its adumbrating image in some of the protozoans. Teir shapes, determination of kind, conditions, in which they live, were determinating the luminars´ visage. Although the inspiring source is stating them the individual luminars presents original, solitary objects.
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