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Difuzní vlastnosti OSB desek v důsledku zasažení nadměrnou vlhkostí.
Žižková, Lucie ; Vertal', Marián (referee) ; Chybík, Josef (referee) ; Bečkovský, David (advisor)
The presented dissertation focuses on the change of diffusion properties in oriented strand board (OSB) panels after exposure to excessive moisture. OSB panels undergo a change in their diffusion properties after being affected by excessive moisture and subsequently dried, causing them to deviate from the original design of the wooden wall structure. The aim of this study is to describe the experimentally measured change in diffusion properties and incorporate it into the composition of a real wooden wall structure, evaluating its performance through computer simulation. The introduction of the dissertation provides the theoretical basis for the experimental section, which includes measurements of water absorption, diffusion properties, and the risk of mold growth. The experimental section describes the approaches and methods used to achieve the objectives of the dissertation. The measurements were conducted on test samples of OSB panels in the laboratories of the Institute of Civil Engineering. After being exposed to excessive moisture, the test samples were dried using two drying methods. The dried test samples were placed in testing assemblies, where diffusion was measured using the dry cup method. The measurements were carried out in two stages, with more than 80 samples measured in each research stage. In the final part, the measurements are evaluated through graphs. The change in diffusion properties was then incorporated into the composition of a real wooden wall structure and assessed using computer simulation, which is more commonly used in practice according to ČSN 73 0540 (Czech Technical Standard).
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Study of the ETICS surface resistance to biotic attack
Těžká, Adéla ; Žák,, Antonín (referee) ; Žižková, Nikol (advisor)
This diploma thesis deals with the study of resistance of ETICS surface treatments to biotic attack. The theoretical part elaborates a research focused on biotic attack of facades of buildings insulated by contact insulation systems ETICS. Based on the information obtained during the elaboration of the bachelor thesis and further study, the optimization methodology of ETICS surface treatment resistance to biotic attack proposed in 2018 is elaborated. In the practical part, the proposed methodology is verified, evaluated and recommendations concerning the suitability of using the proposed methodology in construction practice are implemented.
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Enzymatic hydrolysis of wastes associated with coffee production
Kovářová, Markéta ; Skoumalová, Petra (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis is focused on study of potential production of extracellular hydrolytic enzymes by microorganisms – bacterium and moulds, which have been cultivated on spent coffee grounds. The theoretical part deals with characterization of coffee and utilization of coffee by-products. There are also subscribed microorganisms and enzymes which have been noticed. In experimental part coffee ground was used as the sole substrate for production of extracellular hydrolytic enzymes. Productions of protease, cellulase, mannase and lipase enzymes were observed. None-identified isolate of mould spontaneously contaminating spent coffee grounds was identified as the best producer of these enzymes. Subsequently the conditions of cultivation such as water content and shaking vs. static cultivation of this moulds were optimized. Further, we performed partial purification and pre-concentration of the enzyme cocktail by ultrafiltration, ultradialysis and PAGE-SDS characterization of extracellular enzymes was performed as well.
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Factors influencing the quality of red wine
Zechmeisterová, Lucie ; Vránová, Dana (referee) ; Omelková, Jiřina (advisor)
In my thesis, I focused on monitoring of microorganisms in the sample of red grape juice and on the interactions between yeasts, bacteria and filamentous fungi. Three different media were applied for the cultivation of microorganisms; firstly for monitoring of total volume of microorganisms, secondly for yeasts and third time for lactic acid bacteria. The indirect method was used for the determination of the amount of viable cells. This method consists in enumerating of visible macroscopic colonies grown up on agar plates. When the cells grew up, the forms of colonies were analyzed visually and the morphology of microorganisms was detected microscopically. The operating time of enzymes in grape juice in the production of red wine was monitored after application of commercial enzymatic preparation. The enzym action in grape juice was observed on the basis of the process of degradation of high – molecular substrate by enzymes through the use of Ubbelohd´s viscometer. The research findings provided a lot of knowledge about the occurance of microflora in the process of production of red wine. The commercial preparations added to grape juice played a significant role.
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Analysis of EMW radiation for sterilization of biotic pests
Danielová, Marie ; Svobodová, Kateřina (referee) ; Holešovský, Jan (advisor)
Biotic pests such as wood-destroying fungi, molds, and wood-destroying insects are not only a problem for old buildings but also for newer buildings. Their occurrence has a negative effect on the physical and mechanical characteristic of building materials. One of the main causes of biotic pests in buildings is moisture. Remediation of objects in terms of moisture and biotic pests is a frequent subject of solution in construction practice. There are many methods used to remove moisture and inactivate biotic pests, and their use depends on the individual requirements of individual objects. In practice, this problem is dealt with by specialized companies using well-known technologies or further participate in their research. One of the methods used for moisture remediation and inactivation of biotic pests is the irradiation of building structures using EMW radiation. Microwave heating used to dry moisture from building materials is one of the most intensive methods for sterilizing biotic pests, and due to its intensity, it is a time and cost-effective method.
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Influence of storage conditions on content of biologically active substances in apple fruits.
Ferdová, Jitka ; Čarnecká, Martina (referee) ; Márová, Ivana (advisor)
This study deals with antioxidants in diet and their effects on human organism. Further, it summarizes the agents affect the quality of apples in the course of long-term storage and it outlines the possibility of defence against them. In the experimental part methods of determination of antioxidant enzymes superoxid dismutase (SOD), catalase and polyphenol oxidace (PPO) in apples were introduced. The enzymes were measured in apples tissues in liquid nitrogen after 158 days in normal or modified atmosphere. In Apple the quantitative and qualitative analysis of proteins was realized. Further, some low molecular antioxidants (total phenolics, total flavonoids and vitamin C) as well as total antioxidant status were measured in frozen raw juice. This values were compared with values from apples analyzed immediately after the harvesting. Artificial inoculation with fungi was made in the last part and the fruitfulness was observed.
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Radiators and microbial microclimate
Raputa, Pavel ; Rubinová, Olga (referee) ; Počinková, Marcela (advisor)
This master thesis describes the design of heating in a new one-storey nursery school in Kuřim. The heating systém is designed as a low-temperature systém with a forced circulation of water and a horizontal piping. Three kinds of radiators are used in the design. The panel radiators, tube radiators and free-standing convectors. In this project there are two varinats of the heat source for buliding. The first variant is two gas condensing boilers and the second variant is two heat pumps of an air/water split design. The disign includes air heating in the unit of air conditioning and hot water preparation. The experimental part of the master thesis is focused on microbial microclimate in buildings and radiators contamination by microorganisms. It contains four different experiments, their realization, results and evaluation.
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Production and characteritzation of extracellular hydrolases from selected moulds
Skoumalová, Petra ; Čarnecká, Martina (referee) ; Márová, Ivana (advisor)
This diploma thesis is focused on study of potential production of extracellular hydrolytic enzymes. The theoretical part deals with characterization of selected hydrolytic enzymes, their catalytic properties, the possibility of extracellular hydrolase production by fungi and their applications. In experimental part production strains Aureobasidium pullulans, Fusarium solani and Phanerochaete chrysosporium were used. Productions of cellulase, amylase, xylanase, lipase, protease and lignin-degraded enzymes (laccase, manganese- dependent peroxidase, lignin peroxidase) were observed. Cultivations were carried out in submersed mode in mineral medium supplemented by waste co-substrates such as wheat bran, corn bran, rice bran and oat bran, sawdust, rice, apple fiber, egg pasta and egg-free pasta. Production of enzymes depended on the substrate type and time of cultivation. The highest cellulase, xylanase and amylase activities were measured in the first period of cultivation (3 to 7 day). Lignin-degraded enzymes and proteases were produced at the end of cultivation (7 to 10 days). Lipolytic activity was detected only in A. pullulans, where the activity increased with time of cultivation. The highest value was determined during cultivation on wheat bran (3.6 nmol/ml.min). The highest xylanase and celulase activity (170.3 nmol/ml.min, 248.0 nmol/ml.min) were determined during cultivation of F. solani on corn bran. The highest amylase activity (111.8 nmol/ml.min) was reported in P. chrysosporium during the cultivation on rice. The highest protease activity (68.0 nmol/ml.min) was determined in F. solani grown on wheat bran. The best producer of laccase was A. pullulans, the highest production was recorded for egg-free pasta (27.0 nmol/ml.min). The maximum lignin peroxidase activity (12.5 nmol/ml.min) was measured during the cultivation of F. solani on egg pasta, while the highest yield of Mn-dependent peroxidase (7.7 nmol/ml.min) was achieved during the cultivation of A. pullulans on wheat bran. Lignin-degraded enzymes behaved as inductive, while the other enzymes were produced in mineral medium too. Activity of cellulase in the mineral medium was in A. pullulans strain higher than in media with waste substrates. Enzymes produced into A. pullulans medium were purified by ultrafiltration, ion exchange chromatography and gel filtration.
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Air Conditioning equipment
Frühauf, Patrik ; Rubina, Aleš (referee) ; Rubinová, Olga (advisor)
This thesis deals with the relationship between HVAC systems and internal microclimate of buildings. The work discusses briefly about different components which are formulating internal microclimate. More details are then focused on the issue of microbial microclimate.
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Hodnocení mikrobiologických rizik jedlého hmyzu
Hedvičáková, Adéla
Eating edible insects is an activity that has recently become increasingly important. In order to use edible insects safely, it is necessary to carry out, among other things, an assessment of the risks associated with consumption. This work focused on the microbiological risk assessment of edible insects. The theoretical part of the thesis provides information on the nutritional properties of edible insects and the risks associated with insect consumption. It also mentions legislation related to the inclusion of insects in food. The thesis describes the impact of insects and their consumption on the environment and presents factors that need to be further addressed in the future. The thesis provides a list of important pathogenic microorganisms. In the practical part it is possible to find a statistical evaluation of the measured values of the pathogens present in the insects and in the feed. Total counts of microorganisms, Escherichia coli, Enterobacteriaceae, moulds, Staphylococcus aureus and lactic acid bacteria were determined. The results were compared with those of studies on similar topics.
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