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VCL Components for Vector Graphics in the Instruction of Chemistry
Adamec, Martin ; Cihelník, Simon (advisor) ; Havlová, Michaela (referee)
Předmětem práce je zhodnocení problematiky vzorců ve výuce organické chemie na střední škole, zhodnocení současného stavu softwaru pro kreslení chemických struktur a vývoj VCL komponent pro chemické kreslení. V současnosti dostupný software je na vysoké odborné úrovni a v chemické praxi má široké použití, nehodí se však pro použití ve výuce na druhém a třetím stupni. Výsledkem práce jsou komponenty pro vytváření, zobrazení a manipulaci s chemickými vzorci jednoduchých organických látek v souladu s požadavky střední školy Součástí práce je také aplikace ukazující základní vlastnosti vyvinutých komponent. Kom- ponenty i aplikace jsou vytvořeny v prostředí Borland Delphi 2005. CD s elektronickou verzí textu, zdrojovými kódy komponent i aplikace a spustitelnou verzí aplikace je přiloženo.
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Determination of mercury in selected foods
HAVLOVÁ, Michaela
The thesis resolves problems about the contain of mercury in chosen articles of food. Mercury, hydrargyrum, is a heavy metal, which is an important pollutant of environment. Mercury was determined for comparision in all in nine common articles of food. In rice, mushrooms, fish, lentils, poppy seeds, soya, soya dehydrated slice and oat flakes. Mushrooms were collected in four different provinces of Czech republic. In Highlands, Central province, South Bohemia and in province of Liberec. For comparings were analyzed cultivated mushrooms, Agaricus bisporus, from supermarket. As a fish were analyzed lyofilized samples of catfish, Silurus glanis. The other articles of food were bought in supermarkets. On an atomic absorption spectometer AMA 254 (Altec, Prague, CR), was made validation of analytic method. Results: accuracy (97%), precision (3,33%), sensitivity (0,00251 l/kg), limit of detection ((LOD= 0,31 ?g/l), limit of quantification (LOQ= 1,04 ?g/l), linear dynamic range (LDR= 1,04 až 100 ?g/l) and correlation coefficient of linear part of calibration (0,9979). Measurement of all samples was done with spectometer AMA 254. By analysis of all materials was detected that increased concentration of total mercury in all occures especially in mushrooms. The highest measured value, 5,7 mg/kg, was found in a mushroom Xerocomellus chrysenteron from South Bohemia. Measured concentrations at lyofilized fish weren't important, it was only 0,04 mg/kg. In other articles of food weren't detected overlimited values. We obtained from acquired results, that the highest amount of mercury is contained in our conditions in mushrooms. According to World Health Organisation is determined that the highest tolerable concentration for articles of food is 0,5 mg/kg of mercury. In mushrooms was found after recalculation as a top limit 0,57 mg/kg of mercury. So, this result is overlimited.
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