This thesis develops composition of heat transfer fluids with antifreeze properties next to traditional one component glycols produced from propene and ethene. Based on assessment of physical properties it considers application of progressive antifreeze compounds of glycerine and propan-1,3-diole and their mixtures with classic glycols, which do not have negative influence on the environment and which are produced in last years from renewable sources. Due to the necessity of selection of certain compromise between their heat transfer properties, price, solubility and other factors physical properties of selected mixtures are determined together with synergy of each compound, including formulas with glycols: ethan 1,2 diol and propan 1,2 diol Another evaluated factor of studied formulations in addition to their heat transfer properties was anticorrosive protection of common corrosion inhibitors mixtures. The result of whole work is the proposal of several most perspective formulations based on mixtures of polyhydric alcohols in terms of their features enabling them heat transfer, reasonable costs, and the restrictions of impact of their use, particularly in heat transfer systems, to human health and the environment. The knowledge of physical properties of water solutions of polyhydric alcohols mixtures also helps to better using of recycled materials from planning recycling plant for glycols.

Dizertační práce je zaměřena na studium elektrických a dielektrických vlastností iontových kapalin. Iontové kapaliny mohou nacházet uplatnění v široké škále aplikací, především pak v elektrotechnice. Teoretická část se věnuje popisu základních vlastností iontových kapalin a možností jejich uplatnění v kondenzátorech a elektrochemických senzorech plynů. Experimentální část se věnuje použitým metodám charakterizace vlastností iontových kapalin, jsou zde popsány teoretické poznatky o dielektrické spektroskopii včetně metod stanovení fyzikálních vlastností a vyhodnocení experimentálních dat. Experimentální část je rozdělena na dvě základní části. První se věnuje studiu iontových kapalin pro použití jako elektrolytu v kondenzátorech, druhá část se věnuje studiu vlastností připravených experimentálních senzorů na NO2, zejména vlivem vlastností iontových kapalin na sledované parametry senzoru.

A determination of corrosion inhibitors in engine coolants represent a difficult analytical problem due to their different physicochemical properties. Nowadays a lot of instrument methods are needed to determine them. The aim of this work was the development of methods for their determination using only one instrumentation. Capillary zone electrophoreses was chosen as a suitable technique. Three electrophoretic methods for three groups of corrosion inhibitors were developed. Firstly, method for determination of inorganic anions was developed in range from 5 to 50 ppm with limit of detection around 1 ppm. Background electrolyte contains sodium chromate, CTAB and CHES solution. Analytes were detected indirectly at 450 nm. Another method was for determination of organic acids anions. They were determined in range from 5 to 500 ppm. Limit of detection for each analyte was around 1 ppm. Measurement was made with PDC a CTAC water solution. Indirect detection was used for this determination at 350 nm. Last developed method can be use for determination of aryltrizoles in range from 5 to 500 ppm. Limit of detection was around 1 ppm. As a background electrolyte was used sodium tetraborate solution. The developed methods were validated and their suitability for determination of corrosion inhibitors in real...

Tato práce obsahuje přehled superslitin na bázi niklu, jejich obrábění za vysokého tlaku chladicí kapaliny, týká se také metod optimalizace pro tento typ obrábění a následné analýzy opotřebení nástroje. Tato studie byla vytvořena ve spolupráci se společností Safran, experimentální část byla zrealizována ve výrobním závodě Evry-Corbeil ve Francii. Experimentální část práce se týká optimalizace řezných podmínek pro vnitřní hrubovací soustružení součástí pro letecký průmysl za vysokého tlaku chladicí kapaliny. Cíle práce byly následující: srovnání rozdílných vyměnitelných břitových destiček dodaných společností Safran, návrh hrubovacích strategií a určení optimálních podmínek pro každou z vybraných strategií. Byly uvažovány dvě rozdílné strategie: soustružení s konstantním posuvem a šířkou záběru ostří a tzv. „ramping“. Pro každou ze strategií byla provedena operace čelního a podélného soustružení. Výsledky byly porovnány na základě ekonomického a produktivního kritéria.

This diploma thesis is focused on proposition of non-freezing heat transfer fluid for solar systems. Fluid will be based on mixture of new available compound propane-1,3-diol with water and modern corrosion inhibitors. Then will be investigate, if this new compound is competetive to common used liquids like ethylene glycol or propylene glycol.

This thesis is focused on proposition of non-freezing heat transfer fluid. Fluid will be based on mixture of propane-1,2,3-triol with water and modern corrosion inhibitors. Then will be investigate, if this new compound is competetive to common used liquids like ethylene glycol or propylene glycol.

This diploma thesis is focused on the evaluation of changes in non-freezing heat transfer liquid composed of mixture of polyols and water, used in the real solar thermic system. On the base of the research a new heat transfer liquid is proposed on the platform of 1,3-polyols. The emphasis is put on the non-toxic properties of such system revealing the two chemical candidates for a new heat transfer liquid: 1,3-propanediol and glycerol. These chemicals are mixed together with water using different volume concentrations and properties of such liquids are evaluated.

This thesis deals with the evaluation of changes in properties of an antifreeze heat transfer fluid based on polyols used in real solar thermal system. Emphasis is placed on the use of substances with low impact on the environment.

This project is devided to three parts - theoretical overview of cutting farm components, design of cutting farm for specified production cell and the design of chip conveyor for specified cuting machine. Theoretical overview introduces common commercial used components of cutting farm, their properties and using possibilities in particular regarding their applicability at cutting farm design and chip conveyor design. In the second part there is proposal of design of cutting farm for production cell consist of six identical multi-function machinig centers. For produced amount of chips there is proposal of their processing from the begining at cuting proccess up to their leavig production hall as a briquetts in a containers. At last part of this project there is complete design proposal of chip conveyor for mentioned multi-function maching center. Design is built from a basic line diagram up to design of particular components including calculations and analysis.

The main purpose of this master’s thesis is to propose the methodology suitable for experimental evaluation of additional mass, stiffness and damping by which a liquid layer in the sealing gap affects the rotor. Sealing gaps are important structural elements of hydrodynamic machines. An appropriate design of a sealing gap including the additional effects determination is an inevitable part of the machine overall dynamic design. The thesis also provides a literature search in the field of rotor dynamics and additional effects of a liquid. The designed experiment aiming to determine additional effects of the liquid is based on rotor dynamics evaluation by means of the radial forces measurement. The experiment results were used to determine dynamic properties of dry and wet rotor of the testing device.