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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.
11

Charakterizace hydrogeologického masivu na základě archivních vrtných prací a konceptuální model / Characterization of hard rock environment: archive borehole data and conceptual model

Vacková, Alena January 2014 (has links)
This study is focused on characterization of the hardrock environment in surroundings of Sazava river. It is based on the archival data of groundwater table in boreholes, results of pumping tests from Geofond database and topographic data (DMR , watercourse, etc.). ArcMap 10.1 and Excel were used for data processing. The relations between the groundwater table depth, water table gradient, specific yield, transmissivity and variety of topographic parameters (distance from a watercourse, elevation, relative elevation above the nearest watercourse, the terrain gradient, etc.) were studied. Close linear relationship exists between the gradient of the terrain and groundwater table (rxy 0.96) in the study area. Groundwater table gradient is on average 88 % of terrain gradient. Mean groundwater table gradient is 10 % (6). The average transmissivity in the area is 1.27 x 10-4 m2 /s, specific yield is usually between 0.01 and 0.1 l/s m. This corresponds to the low and very low transmissivity class. Variability of transmisivity values is high. The difference between transmisivity in discharge and recharge zone, assumed by previous authors, was not confirmed in the study area. Specific base flow calculated from mean transmissivity, terrain/ water table gradient and river network density based on Krásný and...
12

Rozdílný dopad minimální mzdy na zaměstnanost napříč regiony EU / The Differential Impact of Minimum Wage on Employment across the EU Regions

Sklenářová, Tereza January 2018 (has links)
Several studies have shown that prices differ across regions and affect standards of living substantially. This thesis investigates whether they cause the differential impact of minimum wage on employment and hours of work across the European Union NUTS 2 regions. Based on the existing regional price estimates of 7 European Union countries and publicly available aggregate regional data, estimates of regional price levels for another 11 European Union countries with minimum wage are obtained. The method that was used for this purpose (multiple imputation) enables to use the resulting estimates as an explanatory variable in another regression as it takes into consideration using imputed instead of observed values by correcting the variances of parameter coefficients. The impacts of minimum wage are investigated for 3 groups of people who are at risk of being affected by its increase - young adults (15-19 years), low-educated individuals and low-skilled individuals. The results indicate that the minimum wage has a negative impact on employment that is higher in regions with higher price levels. The negative effect of minimum wage on hours of work was not confirmed.
13

Systém pro monitorování spotřeby vozidel / A System for Monitoring Vehicle Fuel Consumption

Lazárek, Zbyněk January 2017 (has links)
The aim of this thesis is to create a system that can detect fuel theft from vehicles. The systemconsists of a hardware device located in the monitored vehicles and information systemthat makes it possible to determine when and where the theft occurred. The thesis describesthe components of the hardware device and individual functionalities of the informationsystem.
14

Infračervená magneto-spektroskopie topologického izolátoru Bi2Te3 / Infrared magneto-spectroscopy of Bi2Te3 topological insulator

Mohelský, Ivan January 2020 (has links)
Tato práce se zabývá charakterizací topologického izolátoru Bi2Te3, materiálu s nevodivými stavy v objemu, ale jedním vodivým pásem na povrchu. Tento materiál je zkoumán již přes 60 let, ale i přes to není jeho objemová pásová struktura úplně objasněna, obzvláště charakter zakázaného pásu je stále předmětem diskuze. V této práci jsou prezentovány výsledky infračervené spektroskopie na Landauových hladinách v magnetickém poli až do 34 T, doplněné elipsometrickým měřením mimo magnetické pole. Výsledky těchto měření by měli pomoci vyjasnit některé vlastnosti zakázaného pásu. Pozorovaná optická odezva odpovídá polovodiči s přímým zakázaným pásem, ve kterém se nosiče náboje chovají jako Diracovské hmotné fermiony. Šířka zakázaného pásu za nízkých teplot byla určena jako Eg = (175±5) meV a samotný zakázaný pás se nachází mimo trigonální osu, tím pádem se v první Brillouinově zoně vyskytuje 6 krát nebo 12 krát.
15

Chytré čerpadlo na čerpání vody z nádrže / Smart water pump for water container

Janík, Vladimír January 2021 (has links)
This thesis deals with the implementation of a system for measuring the amount of water in the tank using a 12V water pump. The whole system is controlled by the ESP32 microcontroller. The introduction deals with the theoretical analysis of various principles of measuring the level of liquids. The next part deals with the procedure of the construction of the measuring device and its theoretical analysis. The last part of the work deals with the control of the pump and the individual functions that provide this control. The ultrasonic distance sensor AJ-SR04M was chosen for the implementation of the device. The volume of water in the tank is calculated from its data. The ESP32 microcontroller provides system control via a web interface. The whole system was implemented and tested to measure the volume of water and its pumping in the IBC container.
16

Mikroohybové optovláknové snímače / Microbending fiber optic sensors

Švestka, Jiří January 2013 (has links)
This thesis deals with the influence microbending the transmitted signal at the bare optical fiber. Microbending influence on the transmitted signal is investigated in this work by changing the weight, power and water level in the tank by using this test fixture. The results of the experiments are proposed to enter the laboratory tasks to measure the impact microbending the transmitted signal in the subject line fiber-optic sensors (MOES).
17

Infračervená magneto-spektroskopie polovodičů Rashbova typu / Infrared magneto-spectroscopy of the Rashba-type semiconductors

Šikula, Marek January 2015 (has links)
Optická odezva BiTeX (X = I, Cl, Br) polovodičových materiálů s obřím spinovým štěpením Rashbova typu je studována za nízkých teplot do vysokých magnetických polí, kde je směr magnetické indukce kolmý na povrch vzorku (Faradayova konfigurace). Na rozdíl od reflexního uspořádání nám transmisní uspořádání umožňuje přímé pozorování přechodů mezi Landauovými hladinami v blízkosti křižiště vodivostních pásů - Diracův bod. Optická odezva BiTeX sloučenin je srovnána s teoretickým modelem spočteným v rámci Kubo-Greenwoodova formalismu z Rashbova hamiltonianu.
18

Záznam změn mořské hladiny, cirkulace a disperze sedimentu v hemipelagitech svrchního turonu české křídové pánve / The record of sea-level changes, water circulation and sediment dispersion in the Upper Turonian hemipelagic strata of the Bohemian Cretaceous Basin

Hrnková, Magdalena January 2013 (has links)
The Bohemian Cretaceous Basin was a sediment accumulation, which was deposited as an integral part of the central European epicontinental sea during the Late Cretaceous sea level highstand. It acted as a marine strait and was suited for preserving both nearshore coarse- clastic successions and hemipelagic deposits, allowing for the study of interplay between tectonics, eustatic sea level and paleoceanographic conditions. While the north-western part of the basin was extensively studied in the recent years, little information has yet been collected about the coeval along-shore environments. This thesis is aimed at bringing a new insight into these fine-grained deposits through a detailed lithological, multiproxy and time-series analysis investigation of the Late Turonian record in the Bch-1 drill core, Běchary, Czech Republic. The secular onset of carbonate-rich hemipelagic sedimentation coeval to the base of Teplice Formation is characterised by increased micrite content and changes in geochemical proxies, which are interpreted as changes in the pathway of clay distribution and silt source proximity, combined with elevated bioproductivity. Three orders of statistically significant variability were identified by time-series analysis of selected geophysical properties, two of which are carrying the...
19

Studium elektrického pole v detektorech záření pomocí Pockelsova jevu / Studium elektrického pole v detektorech záření pomocí Pockelsova jevu

Hakl, Michael January 2014 (has links)
Study of electric field in radiation detectors by Pockels effect (Master Thesis) by Michael Hakl Abstract Cadmium Telluride (CdTe) is a convenient candidate for room tem- perature detection of X-ray and gama radiation due to 1.5 eV band- gap energy and high atomic mass. Since CdTe has the highest linear electro-optical coefficient among II-VI compounds, the detector rep- resents a Pockels cell. Transmittance of the crystal is modulated by the internal electric field. Processing of infrared camera photographs results in an electric field profile between biasing electrodes. The elec- tric field in semi-insulting CdTe is influenced with deep level traps causing charge polarization under the electrodes. Occupation of traps is dependent on metal-semiconductor interface. Relation of charge accumulation and band bending for gold and indium contacts was studied. Repolarization/depolarization induced by additional illumi- nation with sub/above bandgap excitation laser was observed and ex- ploited for determination of the deep level energy. Results obtained by the Pockels-effect method were supported with luminescence measure- ments. Correlation between the occurrence of deep levels and surface point defects was discovered. Keywords: Pockels electro-optical effect, Cadmium Telluride ra- diation detector, Electric field, Schottky...
20

Bodové defekty v materiálech pro detekci Rentgenova a gama záření / Point defects in materials for detection of X-ray and gamma radiation

Rejhon, Martin January 2019 (has links)
Title: Point defects in materials for detection of X-ray and gamma radiation Author: Martin Rejhon Department: Institute of Physics of Charles University Supervisor: prof. Ing. Jan Franc, DrSc., Institute of Physics of Charles Uni- versity Abstract: Cadmium telluride and its compounds are suitable materials for pro- duction of X-ray and gamma-ray detectors working at room temperature. How- ever, the detector quality is affected by material imperfections, such as crystal defects and impurities. It results into forming of deep levels which act as re- combination and trapping centers. Then, the accumulated space charge at these deep levels influences electric and spectroscopic properties of the detector. In the end it may result in the polarization effect, when the electric field is localized in vicinity of one contact and detection properties are decreased. This thesis reports a complex study of a detector band structure by various meth- ods with focus on differences between CdTe, CdZnTe, CdTeSe and CdZnTeSe. The electro-optic Pockels effect is used to investigate the influence of the illumi- nation in range 900 − 1800 nm on the inner electric field. The temperature and time evolutions of the electric field after application of bias or switching of the additional light at 940 nm were measured to determine deep levels...

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