|
|
Production of a form for shooting projectile
Procházka, Jan ; Kolář, Ladislav (referee) ; Kalivoda, Milan (advisor)
The bachelor thesis deals with the design and production of a mold for the production of a shooting projectile using the machining technologies. The thesis describes constructional design of the mold, production of 3D component in CAD, creation of NC code and description of the production process. In the end, statistical processing of the produced projectiles is carried out.
|
|
|
The influence of alkali activator on immobilization of metals in alkali activated blast furnace slag
Bystrianska, Emília ; Kalina, Lukáš (referee) ; Koplík, Jan (advisor)
In this work the influence of alkaline activator on immobilization of lead and copper in alkali-activated blast furnace slag was investigated. A total of five activators were used; sodium water glass, potassium water glass, sodium hydroxide, potassium hydroxide and sodium carbonate. The leaching test according to ČSN EN 12457-4 was used to evaluate the level of immobilization of heavy metals, the leached solutions were analyzed by ICP-OES. For a better understanding of immobilization, the selected samples were characterized by analytical methods (FTIR, XRD, SEM, XPS). It was found that the degree of immobilization Pb2+ and Cu2+ in AAS was very high, regardless of the type of alkaline activator used.
|
|
|
Presence of heavy metals near the way Rudná
Chovanec, Petr ; Pavlovský, Jiří (referee) ; Doležalová Weissmannová, Helena (advisor)
These diploma thesis is focused on assessment of hazardous metals in soils near the road Rudná in Ostrava. Seventeen sampling sites have been chosen along this road, samples from this sites were collected in three series. The amounts of mercury, lead, copper, cadmium, zinc, vanadium and manganese were determined. There was also assessed contamination of selected sites using contamination factor and degree of contamination.
|
|
|
Lead connections impact on quality of drinking water
Vostrčilová, Markéta ; Sucháček, Tomáš (referee) ; Biela, Renata (advisor)
The thesis is divided into several parts. First, materials of water supply connections are discussed, which are used today and have been used in the past. Further, it discusses the basic characteristics of lead, lead connections and lead in drinking water. The next chapter describes the development and current legislative requirement for lead content in drinking water. Subsequently it describes risks lead to the organism. The penultimate part consists of an evaluation questionnaire forms on the topic of lead connections, which were filled by water companies. Finally specific data on lead content in drinking water are listed and described from two water companies and selected health institutions.
|
|
|
Selected inorganic pollutants in foodstuffs
Kroupová, Kateřina ; Vítová, Eva (referee) ; Vitoulová, Eva (advisor)
This bachelor thesis is focus on occurrence of inorganic pollutants in foodstuffs. The introduction is dedicated to apperance of individual selected elements in foodstuffs. Concentration of these elements is very important factor for examination of toxic effects for the human organism. If we want to avoid the harmful effects to the human organism, we have to define border limits. Work is based on the legislative of Czech republic. Second part of this study is focused on the biological monitoring. The biological monitoring is important for precautionary measures. In the third part of this study are described toxical effects of these elements to the human organism. Before qualitative and quantitative analysis by instrumental techniques is important to properly take the sample. In the fourth and fifth part of this work are mentioned methods used for determination of these elements and metods of taking samples. This bachelor thesis provide complex view on the problems of pollutants in foodstuffs and it should be used as a base for following diploma thesis.
|
|
|
Application of Diffusive Gradients in Thin Films Technique in Food and Environmental Analysis
Reichstädter, Marek ; Čáslavský, Josef (referee) ; Urík,, Martin (referee) ; Diviš, Pavel (advisor)
Tato dizertační práce zkoumá vývoj techniky difúzního gradientu v tenkém filmu (DGT) pro stanovení rtuti (Hg) a dalších stopových kovů a dále rozšířené možnosti použití této techniky. Technika DGT je v této práci vyvinuta pro stanovení Hg a dalších stopových prvků v různých kapalných médiích. Dvě rozdílná sorpční média specifická pro rtuť byla testována pro použití v technice DGT – Purolite S924 a cysteinem modifikovaná aminopropyl silika (CAPS). Purolite S924 je komerčně dostupný chelatační iontoměnič, CAPS byla připravena v laboratorních podmínkách imobilizací cysteinu na 3-aminopropyl funkcionalizovanou siliku pomocí glutaraladehydu. Obě testovaná sorpční média ukázala slibný aplikační potenciál pro užití v technice DGT díky funkčnosti v roztocích o širokém rozsahu pH i iontové síly. Funkčnost DGT s novými sorpčními médii byla porovnána s technikami DGT s běžně používanými sorbenty Chelex-100 a 3-merkaptopropylfunkcionalizovanou silikou. Hlavní výhodou sorpčních médií Purolite S924 a CAPS je schopnost současného stanovení Hg a dalších stopových kovů (Cd, Pb, Co, Ni, Cu). Vzhledem k odlišným požadavkům na sorpční média používaná v technice DGT nebylo dosud současné kvantitativní stanovení Hg a dalších stopových kovů možné. Doposud byly zapotřebí dvě samostatné techniky DGT – jedna pro Hg a druhá pro další stopové kovy, což zvyšuje množství vzorků pro analýzu a množství použitého spotřebního materiálu. Technika DGT s CAPS byla použita pro stanovení koncentrací kovů v námořních přístavech v Oostende a Zeebrugge na belgickém pobřeží Severního moře. Přestože byla technika DGT původně představena pro použití v analytické chemii životního prostředí, byla v této práci zkoumáno i použití této techniky v analýze potravin. V prostředí rybí omáčky byla ověřena funkčnost techniky DGT a stanoveny difúzní koeficienty Hg a dalších stopových prvků. Technika DGT byla následně použita pro stanovení koncentrace rtuti a dalších stopových kovů v různých komerčně dostupných vzorcích rybí omáčky. Výsledky nově navrhnutého analytického postupu s použitím techniky DGT byly porovnány s výsledky přímé analýzy atomovou absorpční spektroskopií s termální dekompozicí a amalgamací zlatem (TD-AAS) a po mikrovlnném rozkladu vzorků omáčky také s výsledky sektorové hmotnostní spektrometrie s indukčně vázanou plazmou (SF-ICP-MS). Díky předkoncentrační schopnosti techniky DGT byly dosaženy nižší detekční limity ve srovnání s TD-AAS nebo SF-ICP-MS. Technika DGT díky schopnosti oddělení analytů z komplexní matrice rybí omáčky rovněž snížila opotřebení a koroze kovových částí použitých instrumentálních technik.
|
|
|
Cycling of selected metals in the environment.
Šebková, Michaela ; Diviš, Pavel (referee) ; Dočekalová, Hana (advisor)
This bachelor thesis deals with a group of selected metals (nickel, zinc, copper, cadmium and lead) in environmental components. It occupies with natural and anthropogenic inputs of metals to the atmosphere, the water und the soil and with their transport among them components. It engages too in a question of a penetration of metals to the biosphere and in their ensuant transport within the biosphere. At each metal is description of its natural sources, chemical and physical properties, inputs in environment, transport within the biosphere and positive and negative effects on living organism is described for each studied metal. The last chapter of this thesis deals with determination of selected metals in environmental components. It discribes procedures of determination from planning over sampling and processing of sample to the final determination of metals by instrumental methods.
|
|
|
Plasma cleaning of corroded plumb objects
Bubnová, Kateřina ; Grossmannová, Hana (referee) ; Krčma, František (advisor)
This bachelor thesis deals with the application of low-pressure hydrogen plasma to lead corrosion products. There are many historical objects and these objects require careful removal of corrosion layers. Therefore, it is necessary to optimize the treatment process in order not to destroy real historical artefacts in the future. This work is focused on lead, which has not been explored by this method yet. Model samples with corrosion were prepared for comparison and these samples corrode in vapors of concentrated acetic acid and formic acid. There were three working temperatures for plasma chemical treatment because of the low lead melting point and the atomic heating. Argon-hydrogen plasma and hydrogen plasma was applied to 12 corroded samples during the experiment. Process progress was monitored by optical emission spectrometry and surface analysis was performed by SEM, XRD and EDX analysis. The results of these analyzes showed that the most appropriate temperature for plasma chemical treatment was 130 ° C. Based on the obtained results many suggesstions and ideas were obtained for the future research like using of pulse mode and gas composition.
|
|
|
Plant bioindicators of heavy metals
Pecinová, Eliška ; Doležalová Weissmannová, Helena (referee) ; Komendová, Renata (advisor)
The urban areas are exposed to high risk of contamination, and some of the plant species can indicate this contamination. For this study, plants which can accumulate heavy metals and meet the requirements for bioindicators were chosen. Lichens, moss, birch, linden, and yew were chosen as bioindicators. Plant samples were collected from the specified localities in Brno, both with and without heavy traffic, then analysed by atomic absorption spectrometry for the contents of Cd, Cu, Hg, Pb and Zn. Copper (max 47,7 mgkg-1) and zinc (max 200 mgkg-1) were detected in concentrations higher than the lower border of potential phytotoxic concentrations. Lichens and mosses were proved as the best bioindicators for most of the contaminants (Cu, Hg, Pb), except for zinc, which was indicated by birch. Linden wasn’t suitable for biomonitoring. The result concentrations in bioindicators were very variable among localities, without visible effect of traffic load, which implies other factors, which outweighed factors of contamination from the nearby traffic.
|
|
|
Contamination of soil and sediment by hazardous metals
Pidima, Tomáš ; Komendová, Renata (referee) ; Doležalová Weissmannová, Helena (advisor)
This bachelor thesis deals with soil and sediments from the environmental perspective. For selected heavy metals – cadmium, lead and mercury are given information about their occurrence, characteristics and potential sources of environmental contamination. It is also mentioned legislation dealing with the topic. The limit concentrations in soil and sediments, determination methodology and principles of the most commonly used instrumental analytical methods for these elements are described.
|
guest ::
