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Monitoring the properties of phase change materials (PCMs) over time
Šikutová, Eva ; Doležalová Weissmannová, Helena (referee) ; Řezáčová, Veronika (advisor)
The bachelor's thesis deals with monitoring the properties of phase change materials (PCMs, Phase Change Materials) over time. The theoretical block is divided into two parts. The first part focuses on the characteristics of these materials, their preparation and use in various industries. The second part presents methods for measuring the properties of PCMs samples. In the experimental part of this work, PCMs with a known defined history were analyzed by the method of differential scanning calorimetry (DSC) and the obtained results were then processed and evaluated.
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The influence of urban greenery on the quality of the environment
Prokš, Dominik ; Zlámalová Gargošová, Helena (referee) ; Doležalová Weissmannová, Helena (advisor)
This bachelor thesis deals with the topic of the impact of urban green space on the quality of the environment. As the first topic the concept of urbanization appears and closely related to this is what the city as such represents for society. Furthermore, much attention is already paid to urban green spaces and their functions and effects on the urban environment. Public greenery has an impact on air and climate functions, as well as on rainwater management, preventing the spread of noise, trapping dust and, finally, greenery has a positive effect on the psyche of the inhabitants. Furthermore, the maintenance and care of plants and grassland is addressed. In the practical part, is discussed the concept of management and form of public urban greenery in the territory of the Statutory City of Brno, where, among other things, are described the assigned individual managers of urban greenery in the territory of the city and their duties and problems associated with maintenance. The function of the geological and informative system called GIS is also presented, which is an application for the administrators and the public for a clear orientation in the city and its environment. The last chapter is devoted to the measurement of pollutant concentrations in Brno's air.
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Study of bioaccessibility and oxidative potential of elements using simulated lung fluids
Šidla, Jiří ; Doležalová Weissmannová, Helena (referee) ; Cigánková,, Hana (advisor)
This master thesis deals with the determination of the bioaccessible concentration and oxidative potential of an urban aerosol using 3 simulated lung fluids. Submicron fraction (PM1; urban aerosol particles with aerodynamic diameter less than 1 m) was collected in two campaigns (summer, winter). The mass concentration of PM1 was determined gravimetrically and total concentrations of selected metals were determined by ICP-MS. Next, extraction of the sampled filters into 3 simulated lung fluids (Gamble's solution – GS, Simulated alveoli fluid – SAF, and Curosurf) was performed. The extracts were used to determine the bioaccessibility of each metal by ICP-MS and to determine the oxidative potential. Oxidative potential of standard solutions of selected metals and real aerosol samples was also studied using 3 simulated lung fluids. The highest total concentration in PM1 was measured for Fe. The bioaccessibility of most of the studied metals was higher in Curosurf than in GS and SAF. Although the bioaccessibility of most metals was higher in the summer campaign than in the winter campaign, higher values of OP were measured in the winter campaign. OP was higher for extracted PM in Curosurf than in SAF. A study of relationships between measured variables was also conducted using correlations. This work provides a closer look at the effects of inhaled metals contained in urban atmospheric aerosol on human health. The inclusion of Curosurf among the SLFs analysed is also beneficial, as it is a substance used in hospitals for the treatment of respiratory distress syndrome in children.
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Exploring correlation between vegetation indices and plant nitrogen uptake
Pavlačková, Alena ; Doležalová Weissmannová, Helena (referee) ; Kučerík, Jiří (advisor)
Nadměrné hnojení může způsobit znečištění životního prostředí, jako je kontaminace vody a emise skleníkových plynů, a také ekonomické ztráty. Ke zmírnění těchto problémů je důležité přizpůsobit míru hnojení specifickým potřebám plodin. Ve své práci se zabývám možností využití dálkově snímaných vegetačních indexů pro monitorování příjmu dusíku rostlinami a řízení aplikace hnojiv. Měření byla provedena v Oensingenu, Švýcarsku, během stáže na ETH Zürich. Hlavním cílem bylo vyvinout predikční model založený na vegetačních indexech k odhadu příjmu dusíku travní směsi a ozimé pšenice. Dále byla analyzována korelace mezi různými vegetačními indexy a charakteristikami plodin, především příjmu dusíku. Vegetační indexy (NDVI, NDRE, GNDVI, MCARI, EVI) byly získány ze snímků družice Sentinel-2 pomocí Google Earth Engine. Byly změřeny různé charakteristiky plodin, včetně indexu listové plochy (LAI) a výšky plodin, a vzorky ozimé pšenice byly analyzovány na příjem dusíku pomocí elementárního analyzátoru. Do analýzy byla také zahrnuta další data týkající se příjmu dusíku travin z předchozích let. Celkem byla v analýze použita data z let 2021–2023, která zahrnovala hodnoty pro travní směs i ozimou pšenici. Byly provedeny korelační a regresní analýzy k určení vztahů mezi vegetačními indexy a měřenými charakteristikami plodin. Index, který vykazoval nejsilnější vztah s příjmem dusíku plodin, byl poté využit k vytvoření predikčního modelu. Analýza ukázala, že Enhanced Vegetation Index (EVI) byl nejúčinnějším prediktorem příjmu dusíku. Vytvořený predikční model založený na hodnotách EVI dosáhl vysokého koeficientu determinace (R$^2$) 0,89, nízké směrodatné odchylky chyb (RMSE) 1,05 a průměrné absolutní odchylky (MAE) 0,89. Výsledky naznačují, že EVI je spolehlivým indexem pro predikci příjmu dusíku plodinami. Vyvinutý model založený na EVI by mohl být potenciálně použit k optimalizaci aplikace dusíkatých hnojiv na plodiny, což by pomohlo snížit negativní environmentální a ekonomické dopady nadměrného hnojení.
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Lithium and its impact on the environment in lithium battery cell failures
Linney, Phillip George ; Doležalová Weissmannová, Helena (referee) ; Komendová, Renata (advisor)
This bachelor thesis deals with the study of the release of alkali metals and selected heavy metals from battery cells into firefighting water. The battery samples were prepared by superheating them with subsequent explosion and then leaching in distilled water. The change in pH and conductivity compared to distilled water was monitored after a specified time. Flame emission spectrometry and ICP-MS were used to measure elemental concentrations. The measured values of metal contents in aqueous extracts of the battery samples burned in air were compared with those of the samples exploded under water. Some differences were found. A concentration sequence was found for the extracts of the air-burned battery samplesLi+ >> K+ > Na+, whereas for the samples of extracts of batteries burnt in water the concentration sequence Li+ >> Na+ > K+ was found. The concentrations of Na+ ions were around 12.7 mg/l for the samples exploded under water and 275 mg/l thereafter. The K+ concentration was around 19 mg/l for both sample types. Lithium ions were determined the most of all elements measured, averaging 1500 mg/l for air-burned samples and 8200 mg/l for underwater exploded samples. Higher concentrations of Fe, Ni, Cu, Mn and Co were found in the ICP-MS measurements depending on the composition of the battery sample.
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The separation of microplastics from environmental matrices
Pařízková, Mia Victoria ; Řezáčová, Veronika (referee) ; Doležalová Weissmannová, Helena (advisor)
This bachelor’s thesis deals with methods of separation microplastics from soil and the follow up application of quantitative methods of gravimetry, ATR-FTIR and Py-GC/MS. Samples containing model soil and PET or PLA microplastics of different concentrations were prepared. These samples were separated using potassium carbonate solution of known density. The effectivity of separation was measured by gravimetry. The samples were also analysed using ATR-FTIR and Py-GC/MS methods the results of which were compared by correlation coefficients. It was found that ATR-FTIR is a more suitable method, thus it was used for analysis of prepared samples of ten different real soils and PET or PLA microplastics.
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Studium složení emitovaných pevných částic z domácího spalování
Lesná, Barbora ; Mravcová, Ludmila (referee) ; Doležalová Weissmannová, Helena (advisor)
The aim of this bachelor thesis is the analysis of the chemical composition of different biomass samples. Biomass samples underwent combustion in a fireplace stove, simulating combustion in domestic fireplaces. Firstly, biofuels are defined and the difference in chemical composition between wood and herbal fuels, which this thesis focuses on, is being discussed. In the following chapters, the combustion process and various types of emissions being released from the combustion of solid fuels are presented. Attention is paid to legislation and methods of measuring aerosols, then the focus is drawn to methods of their chemical analysis. The last chapters of the theoretical part focus on the health and environmental risks of solid particles that go hand in hand with being exposed to those particles. In the experimental part, the processes of sampling filters with particles, microwave decomposition of the samples. Furthermore, the thesis describes the analysis of the chemical composition of the input fuel, emitted particles and ash, in which metals were determined by the method of absorption atomic spectrometry. The concentration of solid particles on the filter is calculated here. In the discussion, individual fuels are compared according to the content of each metal.
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The problematics of identification and quantification of microplastics in soils
Polachová, Tereza ; Pavlovský, Jiří (referee) ; Doležalová Weissmannová, Helena (advisor)
This bachelor's thesis summarizes the current findings on the presence, behavior and analysis of microplastics in soils. The most common method for analyzing microplastics in soils is FTIR spectroscopy. However, summaries of findings and results of published research indicate insufficient standardization of sampling, purification and handling of samples. The aim was to create a mathematical model for the quantification of PET in mixtures of standard soils and PET, which was subsequently verified on mixtures of PET in different real soils. The result is a model which should be universal for the quantitative analysis of PET in standard and real soils, with low and high PET concentration. Models were created for the following wavenumbers 2965.80 cm-1; 1739.99 cm-1; 1299.85 cm-1 and 1135.31 cm-1. The correlation coefficients R2 for individual wavenumbers were: 0.9606; 0.9141; 0.9360 and 0.8879.
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