National Repository of Grey Literature 25 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Study of chemical processes initiated by electrical discharge in liquids
Možíšová, Aneta ; Zlámalová Gargošová, Helena (referee) ; Kozáková, Zdenka (advisor)
This Bachelor´s thesis in the first part describes the process of ignition of the plasma discharge in water solutions, the generation of the particles that are generated during the discharge and their subsequent analysis by appropriate analytical methods. The second part focuses on specific cases of the use of the plasma discharge in the environment of selected electrolyte, phosphates were selected for individual experiments and for the comparison of sodium chloride. Phosphates were chosen mainly because of their stable pH as a possible benefit in discharge. The aim is to obtain the most ideal environment for the ignition of the plasma discharge and to optimize the method, which could subsequently be used for medical purposes, especially when sterilizing tools
Classification of material used for the construction of garden ponds
Sýkora, Jiří ; Repková, Martina (referee) ; Komendová, Renata (advisor)
This thesis deals with the study of the occurrence forms of inorganic phosphorus in water garden ponds and used material impact on the amount of releasable amount of phosphorus in the form of phosphates in the water medium. The practical part of this work focuses on the analysis and subsequent classification of building materials for the production of garden ponds just by releasing ability of phosphorus in the form of phosphates in the water.
Determination of phosphates in waters and characterization of their negtive effects on water ecosystem
Novotný, Radek ; Komendová, Renata (referee) ; Sommer, Lumír (advisor)
This bachelor thesis is focused on the negative effects of phosphates in natural waters and their methods of determination. The first part is characterized by a negative impact on natural water and there are characterized the problems associated with eutrophication, development of cyanobacteria and algae and the resulting potential health risks. The second section describes the methods by which phosphates can be determined. The work highlights the particular spectrophotometric methods such as molybdophosphoric acid, vanadomolybdophosphoric acid, wolframophosphoric acid, phosphomolybdenum blue and methods with some basic dyes such as rhodamine B, rhodamine 6G, malachite green and crystal violet. There are also mentioned methods, which are used less frequently, but they are relatively sensitive, such as AAS, AES, LC-ICP-MS and next such as chromatographic, electrochemical and enzymatic methods. Finally, work mentions the possibility of using automatic techniques such as FIA or CFA, which are suitable for routine and frequent determination, often using the spectrophotometric methods, but not only these.
Phosphorus and its compounds in the environment
Lefnerová, Marcela ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
This bachelor´s thesis deal with problems of phosphorus in waters, mainly in garden pond. This thesis analyse phosphorus attributes, forms of occurrence and negative effect in excessive occurrence. Next part is concentrate on common methods for remove phosphorus from water and methods of determination in waters and soils. For thesis on important mainly chapter about mobile analyse. Last part deals directly with bathing ecological ponds and Union of founding and maintenance of green. This part occupy with goals this union and introduction of control of materials, mainly from point of view of volume of phosphorus infuse to pond water.
Processing of non-standard products in the production of food phosphates
Hejsek, Michal ; Hrstka, Miroslav (referee) ; Pilátová, Ivana (advisor)
Theoretical part describes production technology and defines sources of nonconforming materials including their hypothetical composition. Chemical processes that take place during reworking were searched for every compound. Practical part focuses on simulation of these processes in laboratory scale. The aim was to explore dependence of whiteness of final product on hydrogen peroxide concentration during reworking.
Manufacture and Properties of Cast Ceramic Cores based on Ethyl Silicate
Bořil, Petr ; Trunec, Martin (referee) ; Vasková,, Iveta (referee) ; Záděra, Antonín (advisor)
The doctoral thesis is focused on the production and properties of cast ceramic cores based on ethyl silicate. The main motivation is to develop a new technology for cast ceramic cores that would solve the shortcomings of Shaw’s original cast ceramic technology and would be viable. Shaw’s original technology has low handling strength of the cores, which lead to the necessity to use steel reinforcements for larger cores and even then the cores were broken due to the different thermal expansion of the reinforcements and ceramics. The Experimental part of the thesis is therefore devoted to the possibility of increasing the handling strength of cast ceramic cores. The influence of granulometric composition of the refractory material, addition of fibers, addition of organic substances and penetration of phosphate on the strength of the cores is described in the individual stages. The knowledge gained in the individual stages led to the development of a new cast ceramic cores technology whose properties are described in the final chapter.
Vlastnosti povrchových vod v závislosti na charakteru krajinného pokryvu v malém povodí
VONDRÁŠEK, Vít
The present thesis covered statistical evaluation of the effect of the management method and the landscape cover on selected hydrochemical parameters of surface water. To obtain and evaluate the necessary data, a model zone was selected, located in the mountains of Novohradské hory. It consists of the upper and lower sub-basins of the stream of Bedřichovský potok, which is the left-hand tributary of the River Stropnice. The sub-basins differ in how management methods are practised locally. While the upper sub-basin generally consists of forests and permanent grasslands, the lower sub-basin has primarily arable land and, in some part, built-up areas. For this reason, it is possible to compare the two sub-basins and evaluate their effect on the selected parameters of surface water; these involved conductivity, concentration of unsuspended solids, total organic carbon concentration, total nitrogen, nitrate nitrogen and phosphate phosphorus. The results show and support a conclusion that surface waters in the lower sub basin, one that is utilised for agriculture, exhibit higher values of the parameters monitored than surface waters present in the upper sub-basin, one that features forest/grassland vegetation cover. It can be noted that arable land has a reduced retention capacity and is more prone to erosion due to its vegetation cover of lesser size; this is also the reason why it is not able to completely retain the desired substances on the agriculturally managed land. This results in deterioration of individual hydrochemical parameters in surface water, such as conductivity or nitrate nitrogen. The thesis is generally indicative of the importance of vegetation cover for the management of water in the landscape.
Multiplication of urea sites—impact on binding phosphates
Salvadori, Karolína
In our work, we focused on the synthesis of sensory groups based on urea structural motifs, suitable for binding phosphates. These units were tested for their selectivity and binding efficiency in HB competitive solvent (DMSO).\n
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Determination of Titanium and Phosphorus by Atomic Absorption Spectrometry
Jeníková, Eva ; Hraníček, Jakub (advisor) ; Rychlovský, Petr (referee)
Předkládaná bakalářská práce se zabývá optimalizací metod stanovení titanu a fosforu technikou atomové absorpční spektrometrie s plamenovou atomizací ve složení acetylen-oxid dusný. Pro jednotlivá stanovení byly experimentálně nalezeny optimální hodnoty pro průtokovou rychlost acetylenu, koncentraci přídavku hliníku či vápníku, výšku paprsku nad hranou hořáku a jiné faktory pro zvýšení analytického signálu. Za těchto experimentálně zjištěných podmínek bylo provedeno stanovení a zjištění základní charakteristiky metod u obou prvků. Významnost stanovení těchto dvou prvků souvisí s tím, že materiály na bázi titanu a oxidu titaničitého povrchově modifikované sloučeninami fosforu jsou perspektivní pro řadu biomedicínských i průmyslových aplikací. Powered by TCPDF (www.tcpdf.org)
The influence of agricultural activities on the stream water quality in natural reservation
NOVOMĚSTSKÁ, Markéta
The aim of this thesis is to evaluate the impact of agricultural activity on hydrochemical parameters of surface waters in connection with the occurence of specially protected species within the surface waters of a monitored area. A model was chosen for the evaluation of the situation - Bedřichovský potok, which is located in Novohradské hory. The river consists of lower and upper sub-waters. Forest management is applied within upper sub-basin, while agricultural management on arable land, meadows and pastures is used in the lower sub-basin. The monitored parameters were indicators of eutrophication of surface waters: Nitrate nitrogen (N-NO3-), Phosphate phosphorus (P-PO43-), and conductivity of undissolved material (NL105). The results showed that the agriculture management (especially on arable land) burdens the soil with nutrients and consequently erosion enters the substances, bringing them to the surface and ground water as a result. There was an increase of substances in the water after rain.

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