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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.
31

Výpočet dynamických sil jističe 630A / Calculation of electrodynamic forces in 630 A circuit breaker

Staněk, Pavel January 2016 (has links)
The aim of this thesis is to simulate the action of electrodynamic forces on current carrying path and a movable contact of the circuit breaker OEZ Modeion BH 630NE. For the calculation there is used the simulation program Ansys Maxwell. The first part is devoted to theoretical analysis of electromagnetic forces on a conductor in a magnetic field. Further I discuss the constructional design of the circuit breaker itself, especially the current path and the contact mechanism. In the next part there is (with using program Autodesk Inventor) created a simplified 3D model of the current path including an arc chamber. With program Ansys Maxwell then there is performed simulation of the acting of forces in each mode. This is magnetostatic and transient analysis for symmetrical and asymmetrical flow of the fault current. In conclusion the results obtained are evaluated and processed in the tabular way.
32

Střídavý zdroj se vzdáleným řízením / AC power supply with remote control

Štěpnička, Martin January 2016 (has links)
The project describes the design of controlled inverters or power generator simulating one phase of European or American distribution network. The generator is able to enter into an output signal of a certain fault conditions designed to testing the electromagnetic compatibility of connected devices. The text is divided into three main chapters. The first one deals with the design of the power generating low-frequency signal. The second part describes the power source used for this generator. In the third section describes the program management unit. End of text summarizes the results. The annex contains a schematic designs and printed circuit boards.
33

Kolorimetr / Colorimeter

Škoda, Pavel January 2017 (has links)
This thesis deals with the analysis of the color parameters for their subsequent use in the design of the device, which will be used to measure their stability in continuous production. The theoretical part defines the basic concepts and knowledge needed to understand the problems. In addition, there are described individual components and sensors suitable for color measurement. The practical part deals mainly with the descrip- tion of the construction of the colorimeter, its individual parts and the creation of the control program. At the end, there are results of the testing of the product and their overall assessment
34

Modelování propagace signálu bezdrátových sítí LTE a WiFi uvnitř budov / Modeling of Signal Propagation in Wireless LTE and WiFi Networks in Indoor Deployment

Olbert, Jaroslav January 2017 (has links)
Masters thessis deals with the problematics of wireless signal propagation modeling inside buildings. The theoretical part of this thessis describes principles and methods of electromagnetic waves spreading in open areas and in indoor deployment. There are also described methods used for calculating the path of signal propagation ray-launching and ray-tracing. This part also includes description of an algorithm and equations used for simulating 5GHz WiFi signal propagation inside the Department of telecommunications corridors. Second part of this thessis includes a description of a NS-3 module mmWave, which was used for simulations of IEEE 802.11ad (WiGig) standard. There are also results of these simulations and their detailed description. At the end of this thessis comparison of these results with values gained by real environment measurements can be found.
35

Likvidace biotických škůdců prostřednictvím EMW záření / Disposal of Biotic Pests by EMW Radiation

Sobotka, Jindřich January 2015 (has links)
The possibility of using high-frequency electromagnetic radiation in the construction sector is a common knowledge. Various experiments have been carried out to dry construction materials, or even to destroy biotic pests. However, the majority of these experiments have been executed in laboratory conditions. It means they have been carried out under exact limiting conditions, often very far off those conditions in real building practice. Therefore, this dissertation aims at exploring the possibility of utilizing microwave technology in drying and heating of construction materials, in disposing of biotic pests and sterilizing building materials under real conditions in building practice. The thesis will explain that microwaves are a term given to a part of electromagnetic radiation. Electromagnetic radiation is based on the principle that the radiated energy is absorbed by water molecules present in moist building material. In the mass of the irradiated material, the radiated energy is transformed into thermal energy, where a so-called “motion” of water molecules occurs with the energy then being transformed into kinetic energy. The microwave technology itself offers a very wide range of use, which can be easily achieved, thus making the technology available to use in the future. Part of the experiments and the necessary measurements, too, has been carried out on selected types of building materials in the premises of the Faculty of Civil Engineering of Brno University of Technology. They have been executed under conditions which most closely correspond to the conditions in real buildings. Part of the experiments and the necessary measurements were carried out on particular constructions, by the so-called in situ method. As stated in the conclusion of the dissertation, laboratory measurements and the in situ measurements differ considerably in some cases.
36

Interpretace georadarových měření s využitím kombinovaného geoelektrického průzkumu / GPR data interpretation with use of a combined geoelectrical survey

Široký, Jakub January 2016 (has links)
GPR data interpretation is often difficult due to complex geological environments, reflections ambiguity and time-depth conversion uncertainty. Thanks to the geophysical fields interoperability it is possible to compare results of related survey methods. Radargrams from three model sites were processed and interpreted in an usual way to uniformly amplify all recorded reflections. Results were compared with ERT and EM (DEMP) data within integrated interpretation. GPR data interpretation was extended and new geological and geomorphological interpretations were uncovered. The GPR processing sequence was modified and simplified following outcomes from the integrated interpretation to ease different methods results comparison. Adapting a velocity model to precise time- depth conversion hasn't showed improvements. Key words: ground penetrating radar, electrical resistivity tomography, dipole electromagnetic profiling, integrated interpretation, integrated inversion, GPR processing optimization, sedimentary environment, velocity model
37

Využití elektromagnetických indikátorů při průzkumech železobetonových konstrukcí / Using electromagnetic indicators from surveys of reinforced concrete structures

Tkadleček, Petr January 2016 (has links)
The diploma thesis describes non-destructive methods for diagnostics of reinforcement. It is focused on the method of electromagnetic indicators. In the first part the methods are described and compared. The profometer PM-630 is also described. The second part describes experimental measurements with profometer on reinforced concrete structures. The results are described and interpreted. The effects, which have influence on measurement, are described. The recommendations for practical measurement with profometer are described. The experimental models were created for calibration of profometer. The part of this thesis is also the determination of load bearing capacity of reinforced concrete bridge in Nosislav.
38

Srovnání znalostí z teorie elektromagnetického pole u laiků a odborníků v rámci civilní nouzové připravenosti / The comparison of knowledge of electromagnetic field theory for laymen and experts within the civil emergency preparedness

VESELÁ, Barbora January 2016 (has links)
The thesis "Comparison of knowledge of electromagnetic field theory of the laity and experts in the context of civil emergency preparedness" to put three goals: 1. The formation of the structure of an electromagnetic field for experts. 2. The reaching of the comparison of knowledge among experts and laymen. 3. Statistical processing of the results. The author has set the following hypotheses: H1. Theoretical distribution of knowledge in a sample of the general public will have a normal distribution . H2. Theoretical distribution of knowledge in a sample of professional community will not have a normal distribution. H3. The comparison of knowledge among the experts and the laymen will lead to an alternative hypothesis. The thesis was based on the knowledge of the theory curricular process. On the basis of this theory was made up not only the structure of the electromagnetic field, but also the questionnaire. An important step in this thesis was the creating a model structure of electromagnetic field . The structure was based on an analysis of the scientific system - the system of educational programs in the field of civil protection.The same structure was applied to the general public. An important step was to compare the knowledge of protect the population from experts and laymen. This issue has not been investigated in detail and it did not compare the knowledge of laymen and experts in the studied physics. The idea came from the possibility of extraordinarily events where respondents can meet with electromagnetic fields and will need the relevant theoretical knowledge. The aim was to the statistical evaluate of the applied questionnaires. There were applied nonparametric and parametric testing as the verification methods. The theoretical division of knowledge of experts is supposed Poisson distribution, on the contrary, the theoretical division of the general public should have a normal distribution. There was also compared the difference between knowledge of laymen and professionals. The using of the statistical methods have been received and confirmed the hypothesis and the thesis goals were fulfilled.
39

STUDIUM ZMĚN VLASTNOSTÍ BIOLOGICKÝCH MATERIÁLŮ V ELEKTROMAGNETICKÝCH POLÍCH / STUDY OF CHANGES OF BIOLOGICAL MATERIAL CHARACTERISTICS IN ELECTROMAGNETIC FIELDS

Vlachová Hutová, Eliška January 2021 (has links)
Presented dissertation discusses the influence of electromagnetic fields on the weight of the particles, which are considered in this work as substances with the hub. Theoretical knowledge was practically tested on plant organisms (early somatic embryos, fungal pathogens), theoretically the influence of electromagnetic field on cell structure was modeled. It was subsequently confirmed by a practical experiment assumption about the influence of electromagnetic fields on the weight of the particles. These experiments were preceded by a theoretical study of the problem and the formulation of a solution using Maxwell's equations, from which other descriptive equations and formulas were derived. The results of the experiments were presented at several professional conferences and published in professional journals and proceedings.
40

Analýza dosahu signálu bezdrátových sítí / Analysis of Wireless Signal Coverage

Šimek, Petr January 2017 (has links)
This master's thesis describes process of design and development of the system for calculating the coverage of wireless networks, it is implemented as a web portal and written in the Java programming language. The text of the thesis describes the work with the used platforms, a description of the ITU-R calculation method P.1812, which is used for calculation electric field strength and basic information about electromagnetic waves. The main function of the system is to calculate and display coverage of wireless networks and customer management information.

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