National Repository of Grey Literature 38 records found  beginprevious19 - 28next  jump to record: Search took 0.00 seconds. 
Walden´s law utilization in diagnostics of electroinsulating liquids
Gőtz, Lukáš ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This bachelor`s thesis deals with utilization of Walden’s law in diagnostics of electroinsulating liquids. It is studied electrical conductivity, dynamic viscosity, density of liquids and measurement methods. Measurements are realized on experimental sample of transformer oil ESTO BNX by created measuring laboratory workplace.
Properties of fluids
Dzjamko, Vladislav ; Štefan, David (referee) ; Himr, Daniel (advisor)
The aim of this thesis is to present the basic equations describing the behaviour of fluids and to describe the substance characteristics that are present in them. The thesis is divided into four successive chapters, the first two of which explain the causes and consequences of the various fluid properties. The following chapter is devoted to equations and their derivation. Finally, the content of the thesis includes a description of some methods for determining selected material constants.
Experimental Determination of Turbocharger Mechanical Losses
Kudláček, Petr ; Doman, Jozef (referee) ; Novotný, Pavel (advisor)
This master’s thesis deals with mechanical losses in turbochargers. The theoretical part provides general information of the methods of support the turbocharger rotor, then focuses on hydrodynamic bearings. The thesis analyzes the occurrence of mechanical losses and the effects that affect them. An important part of this thesis focuses on the determination of mechanical losses and their possibilities. A test stand was compiled for the possibility of experimental measurement of mechanical losses. Several test measurements were performed on this test stand at different operating modes. Simultaneously, the determination of mechanical losses was performed using two other methods. Based on these measurements, it was also possible to perform an evaluation and analyze the occurrence of mechanical losses depending on the set operating conditions. A comparison of individual methods for determining mechanical losses performed in the experimental part was performed. At the end of the thesis, the possibilities of the test stand were defined based on the performed measurements.
Use of fluxing additives to modify the properties of asphalt binders
Šefránková, Radka ; Koudelka, Tomáš (referee) ; Dašek, Ondřej (advisor)
The subject of the thesis is to describe the effect of fluxing additives on the behaviour of asphalt binders. Emphasis will be placed on changes in rheological properties of asphalt binders at intermediate temperatures, stability during aging and influence of fluxing agents on their low-temperature properties. Theoretical part will deal with the principle of asphalt binders aging and it will summarize knowledge about fluxing additives. Further, empirical and functional tests will be described in order to evaluate asphalt binders. In the practical part, all laboratory tests will be evaluated and the effects of two different fluxing additives will be compared.
Influence of polymer modified bitumens storage on their properties
Měšťanová, Petra ; Fišer,, Jiří (referee) ; Dašek, Ondřej (advisor)
Subject of this bachelor’s thesis is to describe the influence of long-term storage of polymer modified bitumen at temperature of 180 °C on their properties. The principle of binder modification and test procedure of needle penetration, softening point, elastic recovery and dynamic viscosity in DSR will be explained in the theoretical part. The properties changes of five tested modified binders during storage will be evaluated and compared in the practical part.
Dynamic viscosity of asphalt binders
Broďák, Marek ; Coufalík, Pavel (referee) ; Dašek, Ondřej (advisor)
The bachelor thesis describes a laboratory characteristics of bituminous binders. The principle, procedure of meansurment and comparison of test results of dynamic viscosity, needle penetration and softening point by ring and ball method will be described. The tests will be performed on samples of the bituminous binders with different degree of modification.
Study of alternative electroinsulating liquids properties
Bannert, Tomáš ; Hylský, Josef (referee) ; Frk, Martin (advisor)
This bachelor´s thesis is dealing with the study of alternative electrical insulating properties of the materials used in the electronics industry, particularly liquids based on natural esters and especially their constituents in the form of higher fatty acids and esters. The work is divided into theoretical and practical part. The theoretical part deals with the characterization of vegetable oils, their constituents and mineral oils, their comparison in terms of electrical and non-electrical properties and current state of the use of vegetable oils and their constituents in the electronics industry. Further it’s dealing with analysis of diagnostic methods for these characteristics. In the experimental part were analyzed electrical and non-electrical properties of selected samples of vegetable oils, their constituents and mineral oils such as the density, the dynamic viscosity and the complex permittivity and its parts as relative permittivity and loss number. Evaluations of the results of each group are compared with each other.
Ageing of asphalt binders
Střasáková, Monika ; Hegr, Zdeněk (referee) ; Dašek, Ondřej (advisor)
The theoretical part of this thesis describes the rheology of bituminous binders, aging of asphalt binders and laboratory methods simulating short and long term aging. The following describes an empirical tests (needle penetration, softening point ring ball method) and functional tests (complex shear modulus and phase angle, dynamic viscosity), which are performed in the dynamic shear rheometer. At the end of this section, laboratory aging of bituminous binders using method RTFOT and method RTFOT + PAV is described in more detail. In the practical part of this thesis, the results of all tests performed on the binders aged using RTFOT + PAV are introduced and compared with results of properties of non-aged binders and binders aged by 3xRTFOT.
Determination of the viscosity of various types of wastewater
Glombová, Pavla ; Rusník,, Igor (referee) ; Hluštík, Petr (advisor)
The aim of this diploma thesis is a description of viscosity as a physical characteristic of liquids, next a description of projecting different types of sewer systems (pressure sewer system, vacuum sewer system and gravity sewer system). There was a range of density and viscosity of wastewater experimentally determined. These values were compared with ordinary values used in practice. The practical part of this work consists of sampling wastewater from different types of sewer systems and various localities. Chemical-biological analysis was realized on those samples with defined density, then dynamic viscosity was measured by the rotary viscometer for various temperatures. Measured data are evaluated. Finally, a calculation related to the design of sewers was made.
Rheological properties of asphalt binders
Pěnčík, Michal ; Mondschein,, Petr (referee) ; Hýzl, Petr (advisor)
The Diploma thesis is focused on rheological properties of bituminous binders and mixtures. Above all, it describes the changes of these properties of samples of bituminous binders and mixtures. Those were brought by the process of laboratory aging, since it simulates the changes occurring in the in the real-life conditions. The theoretical part depicts the field of rheology and methods utilized for simulating the ageing of binders and mixtures. The practical part describes the process of preparation of samples and its testing. Firstly, the ageing of bituminous mixture by the means of BSA method (Braunschweiger Alterung) took place, which was followed by preparing the solids for testing the modulus of stiffness and main testing. The rest of the mixture was used for extracting the binder. Tests with the binder were focused on the usage of dynamic shear rheometer (complex shear modulus, dynamic viscosity). The last part of the work is dedicated to the comparison of the outcomes of testing.

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