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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Koncepční návrh sekundárního a terciálního okruhu pro nový jaderný zdroj / Conceptual design of secondary and tertiary circuit for a new nuclear source

Valíček, Roman January 2021 (has links)
The aim of this thesis is to create a conceptual design of the secondary and tertiary circuit of a new nuclear power plant in our country, which is preceded by a brief search of particular generations of nuclear reactors. The VVER-1200 reactor became the model for the new nuclear power plant. There was designed a heat diagram containing primary components in this work. After that, there was the balance calculation and calculation of parameters of the main devices of the proposed scheme such as condenser, low-pressure and high-pressure regeneration exchangers and steam generator.
182

Vývoj procesních parametrů pro zpracování hliníkové slitiny AlSi7 technologií Selective Laser Melting / Development of process parameters for Selective Laser Melting technology for processing of aluminum alloy AlSi7

Zvoníček, Josef January 2018 (has links)
The diploma thesis deals with the study of the influence of process parameters of AlSi7Mg0.6 aluminum alloy processing using the additive technology Selective Laser Melting. The main objective is to clarify the influence of the individual process parameters on the resulting porosity of the material and its mechanical properties. The thesis deals with the current state of aluminum alloy processing in this way. The actual material research of the work is carried out in successive experiments from the welding test to the volume test with subsequent verification of the mechanical properties of the material. Material evaluation in the whole work is material porosity, stability of individual welds, hardness of the material and its mechanical properties. The results are compared with the literature.
183

Počítačové modelování teplotní hystereze při změně skupenství / Computer modelling of phase change hysteresis

Petrášová, Anna January 2021 (has links)
This thesis deals with computer modeling of temperature hysteresis during phase change, namely complete and partial phase change. There is performed a review of methods for modeling temperature hysteresis based on the enthalpy method and the effective heat capacity method. In the case of complete phase change, there are several methods that use the effective heat capacity method, as well as the heat source method, which, on the contrary, is a certain analogy of the enthalpy method. The following are works dealing with modelling of partial phase change, the most interesting of which is due to the validation method of static hysteresis and the method designed by Bony and Citherlet. The second part of this thesis deals with the hysteresis behavior of the material with phase change, which is organic paraffin RT 27. The input data obtained by differential scanning calorimetry was converted to the dependence of the enthalpy on temperature. These curves was represented by piecewise linear function. In the case of partial phase transformations, a modeling method based on the methods proposed by Bonym and Citherlet was designed. An one-dimensional model enabling thermal simulation of the material was implemented in the MATLAB software environment. The results obtained with this simulation are finally compared with a model that does not consider thermal hysteresis.
184

Studium vlivu vícefaktorového namáhání na dielektrická spektra izolačních materiálů / Study of multistress ageing influence on dielectric spectra of insulating materials

Vojtek, Vítězslav January 2008 (has links)
This work deals with the influence of multistress ageing (electrical and thermal stress) to relaxation effects depending on defined conditions had being labored.
185

Působení vlhkosti na vlastnosti izolačních materiálů vystavených tepelnému a elektrickému namáhání / The moisture effect on properties of insulating materials exposed to thermal and electrical stress

Janošek, Michal January 2008 (has links)
The diploma thesis with experimental verification influence moisture of the dielectric properties of non-aged and thermally, electric and multistress aged slot insulation Isonom NMN. Above all both components of the complex permittivity are examined in dependence on frequency during the thermal, electric and multistress ageing. Practical part is specialized on design, realization and examination of workplace multistress ageing.
186

Synergické účinky kombinovaného stárnutí elektroizolačních materiálů / Synergic effects of multistress ageing of electroinsulating materials

Novák, Lukáš January 2010 (has links)
Submitted work deals with monitoring impact of thermal and electric ageing on the dielectric properties of insulating material NKN 0887. In the course of the experiment five sets of dielectric insulating materials were aged. The voltage range has been set from 1,5 kV till 2,2 kV and temperatures were 23 °C and 200 °C. The capacity and loss factor has been directly measured by RLC meter Agilent with attached electrode system. The electrode system operates on the principle of a plate capacitor. The values of relative permittivity and loss number has been calculated from values of capacity and loss factor. For easier confrontation has been frequency dependences of these values plotted in a chart. The Cole-Cole diagrams has been created and factors of Havriliak-Negami function has been calculated. Data has been compared with each other and the effect of ageing factors has been deduced.
187

Termomechanická spolehlivost pájeného připojení elektronických modulů s LTCC / Thermomechanical reliability of solder connection in electronic modules with LTCC

Krajíček, Michal January 2011 (has links)
This thesis is considered about interconnect PCB with microelectronic and electronic modules and continuing on thesis MODERN CAUSES OF ASSEMBLY MICROELECTRONICS AND ELECTRONICS MODULES. This thesis includes, definition of termomechanical strain in solder joints and description of LTCC technology. Practical part includes characterization the causes of assembly with usage chip component and proposal footprint for PCBs, modules and results of temperature cycling of tested modules.
188

Nekonvenční aplikace hybridních integrovaných obvodů / Non conventional applications of HIC´s

Klíma, Martin January 2011 (has links)
This thesis deals with non-conventional applications in the area of thick film technology, especially with indication of the temperature by thermodynamic sensors. The work summarizes thermodynamic sensors theory and also contains production data of the universal thermodynamic sensor realized on ceramic substrate, including measurement of its parameters and heat radiation.
189

Analýza teplotních dějů uvnitř článku olověného akumulátoru v režimu kyslíkového cyklu / Analysis of thermal processes inside of lead acid battery cell in oxygen cycle regime

Vondrák, Michal January 2013 (has links)
The aim of this thesis is the analysis of thermal processes in lead accumulators with oxygen cycle. The work is explaining the structure and principle of operation of the standard lead-acid battery and lead-acid battery with oxygen cycle. Generally are described thermal action inside a lead battery with oxygen cycle and the different types of heat generated during operation of the battery are discussed in detail. One chapter describes the practical experiments and their results.
190

Inteligentní řízení akumulačního ohřevu teplé vody / Intelligent control of the storage water heater

Vašica, Radoslav January 2014 (has links)
The work generally deals with the possibilities of preparing hot water in household and analyzes saving posibilities. At the beginning of work the history of hot water preparation is briefly indicated. Chapter 3 deals with different ways of heating. Described in more detail electric storage heating is in chapter 4, where can be found the effect of heating to the power network, especially to the daily load diagram. The following are the information of the tariff policy, as a tool for motivation of consumers, for using the storage heating. In the next part, beginning with the fifth chapter, is written about the possibility of energy saving by means of intelligently controlled boiler. That eliminates the disadvantage of storage heating, which are the tank thermal losses. Heating is based on a certain regularity in the behaviour of the user and manages the preparation of water according to expected consumption. The sixth chapter then contains design of own algorithm for economical control of heating and also energetic and economic assessment of potential savings.

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