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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.
41

Modifikace organických vysoce výkonných pigmentů pro aplikace v organické elektronice / Modification of Organic High Performance Pigments for Applications in Organic Electronics

Cigánek, Martin January 2020 (has links)
Dizertační práce pojednává o studiu, syntéze a chemické derivatizaci molekul spadajících do skupiny organických vysoce výkonných pigmentů a jejich potenciálním uplatnění v oblastech organické elektroniky. Teoretická část práce je zaměřena na nejnovější trendy v dané oblasti, a to jak z aplikačního potenciálu konkrétních derivátů, tak z pohledu syntetických možností a jejich strukturálních derivatizací. V experimentální části je pak podrobně popsána příprava pestré škály intermediátů a výsledných produktů, zahrnujících deriváty diketopyrrolopyrrolů (DPP), benzodifuranonu (BDF), epindolidionu (EP), naphthyridinedionu (NTD) a polymeru na bázi thiofenu (PT). Celkově bylo nasyntetizováno 103 molekul, přičemž 49 tvořily výsledné produkty, z nichž 27 bylo zcela nových, dosud nepublikovaných. Hlavním motivem derivatizace molekul pigmentů je zde inkorporace derivátů adamantanu do finálních struktur. V další části práce jsou blíže diskutovány jednotlivé chemické modifikace vedoucí k výsledným produktům. Na sérii N,N'-; N,O'- a O,O'-substituovaných derivátů DPP je popsána komplexní studie vlivu charakteru alkylových řetězců a také pozice jejich navázání v molekule DPP, a to nejen na selektivitu reakce, ale rovněž na optické i termické vlastnosti syntetizovaných produktů.
42

Komplexní simulační model vibračního generátoru / Complex simulation model of vibration power generator

Harapát, Jan January 2013 (has links)
This work is focusing on analysis of current development in energy harvesting projects in aerospace industry field, and on analysis of current development in vibration generator field. It is also concentrating on establishment of a complex simulation model of vibration generator. It deals with modeling of magnetic field of generator and its cross connection with a mechanic and an electronic model.
43

Návrh zařízení pro Power HIL simulaci stejnosměrného motoru / Design of unit for Power HIL simulation of DC motor

Chalupa, Jan January 2014 (has links)
This thesis deals with analysis and implementation of Power-HIL system that is designed to simulate real DC motor with comutator and permanent magnets. For problem analysis were used simulations of real components in Matlab / Simulink. The electronic parts of system were simulated with using the SimElectronic library. Idividual hardware components were designed according to simulation results. The outcome of this thesis is a power electronic simulator of real DC motor, which is implemented on dSPACE platform. The system allows software to setup parameters and behavior of simulated motor. The final system can be used for testing DC motor ECU (electronic control units).
44

Studium dielektrických vlastností struktur tenkých vrstev organických materiálů / Study of dielectrical properties of organic material thin films

Pospíšil, Jan January 2016 (has links)
The dissertation is focused on the study of electric and especially dielectric properties of thin film organic materials with their huge potential for optoelectronics and other industrial sectors. The theoretical part deals with the use of organic materials in organic photovoltaic cells, the methods of deposition techniques and characterization. The theoretical knowledge of the dielectric spectroscopy, including methods for determining the physical properties and evaluation of experimental data are also described. The experimental part is devoted to the study of small molecule organic solar cells with bulk heterojunction composed of electron donor molecule of DPP(TBFu)2 and electron acceptor fullerene derivatives, such as PC60BM, PC70BM and TC60BM. The experimental part is divided into two main parts. The first part deals with the study of processes occurring at the interface between the active layer and the contact; the second part is focused on transport processes inside the structure of photovoltaic cells and also contains a study of perovskite solar cells.
45

Hodinkohled: Etnografie uživatelské zkušenosti s Apple Watch / A Watch To Watch: Ethnography of User's Experience with Apple Watch

Zavoral, David January 2020 (has links)
This thesis builds upon ethnography of Apple Watch user experience and explores its connections with Apple's different branding strategies such as official website advertisements for Apple Watch Series 4, Supplier Responsibility Progress Report (2019) and Today at Apple sessions held in Apple Stores. I draw on sociomaterial approaches with special emphasis on John Law's (2004) method-assemblage and the feminist critique of ANT managerial vision that allow me to conceptualize corporate practices as means of enacting singular and coherent commercial out-thereness and absences. The goal of this thesis is to explore possible connections between the user's experience and the corporate branding strategies which craft a series of commercial realities in order to translate the needs of other actants and enroll them in its corporate network. This paper also argues that ambivalence is central to this process as corporate branding is being constantly reshaped and reconfigured by both the branding strategy itself and the actants involved. Chapter I provides a semiotic analysis of advertisements inspired by Woolgar's (1990) concept of moral universe. The second chapter follows with examining the Progress Report which provides information on the production processes that are completely absent in exclusively...
46

Metody SPM založené na sondách vyrobených z křemenného rezonátoru / SPM Methods Based On The Quartz Resonator Probes

Wertheimer, Pavel January 2015 (has links)
The thesis is focused on development of scanning probe microscope systems, especially development and implementation of quartz resonator probes. The quartz resonator probes, compared to the standard silicon cantilevers, have several advantages. It is in particular their mechanical properties and possibility of direct electrical readout of the deflection signal. Due to the fact, the probes are easy to implement even into more complex SPM systems. The thesis deals with development of universal and open SPM control system electronics. The electronics consist of the commercial SPM control and oscillation units, the development of the other electronic parts (such as the high voltage amplifier and the preamplifier units) is described in the thesis. Further, the thesis reports on development of the qPlus UHV LT SPM microscope system that was carried out at Universität Hamburg. Part of it was development of the qPlus preamplifier able to operate at liquid helium temperature. The third topic of the thesis is the implementation of qPlus technology into the UHV VT SPM microscope suitable to operate in situ with a scanning electron microscope. The qPlus sensors and the universal UHV preamplifier were designed and manufactured. Test measurements were conducted on all of the developed systems.
47

Využití moderních technologií při výuce školní TV / Use of Modern Technologies in Physical Education at Schools

Palička, Pavel January 2018 (has links)
Pavel Palička - Use of Modern Technologies in Physical Education at Schools Abstract Problem: The use of digital technologies in education is one of the possibilities how to support the pupils' motivation. Physical education (PE) offers a variable environment where various types of actual wearable technology (smart phone, tablet etc.) can be used. No integrated overview of possibilities and practical recommendations for the use of available digital technologies (DT) in physical education has been published. There is also lack of research results measuring impact of their use on everyday school practice. Hypothesis: It was hypothesized that pupils who receive innovated experimental education programme using digital technologies will have better relationship to PE and greater intrinsic motivation to exercise. Objective: The purpose of this study was to identify changes in intrinsic motivation and relationship to physical activity in physical education triggered by an experimental DT- involving education programme. Methods: The research was carried out in form of a quasi-experiment conducted in physical education lessons in school years 6-9. The research sample (N=237) consisted of two groups. A group of 119 pupils in experimental lessons was compared with a control group of 118 pupils who went through...
48

Misconceptions regarding direct-current resistive theory in an engineering course for N2 students at a Northern Cape FET college / Christiaan Beukes

Beukes, Christiaan January 2014 (has links)
The aim of this study is to ascertain what misconceptions N2 students have about DC resistive circuits and how screencasts could effect on the rectification of these misconceptions. This study was conducted at the Kathu Campus of the Northern Cape Rural Further Education and Training College in the town Kathu in the arid Northern Cape. The empirical part of this study was conducted during the first six months of 2013. A design-based research (DBR) method consisting of four phases was used. DBR function is to design and develop interventions such as a procedure, new teachinglearning strategies, and in the case of this study a technology-enhanced learning (TEL) tool (screencast) with the purpose of solving a versatile didactic problem and to acquire information about the interventions of the TEL tool (screencast) on the learning of a student. In the first and second phase of DBR quantitative data for this research were gathered with the Determining and Interpreting Resistive Electric circuits Concepts Test (DIRECT) in order to determine the four most common misconceptions. The DIRECT test was conducted in the first trimester to find the misconceptions; the test was conducted in the second trimester also to confirm the misconceptions. Further quantitative data were collected from a demographic questionnaire. The qualitative data were collected by individual interviews in the fourth phase of the research project. Phase three of this study was the development of screencasts in the four most prominent misconceptions in DC resistive circuits of the students. The respondents of this study were non-randomly chosen and comprised of two groups, one in the first trimester of the year and one in the second trimester of the year, which enrolled for the N2 Electrical or Millwright courses. The respondents were predominant male and representing the three main cultural groups in the Northern Cape namely: Black, Coloured and White. The four misconceptions on DC resistive circuits that were identified were: (i) understanding of concepts, (ii) understanding of short circuit, (iii) battery as a constant current source, and (iv) rule application error. Screencasts clarifying the four misconceptions were developed and distributed to the respondents. On the foundation of the results of this research, it can be concluded that the students have several misconceptions around direct current resistive direct current circuits and that the use of TEL like screencasts can be used to solve some of these misconceptions. Screencasts could supplement education when they were incorporated into the tutoring and learning for supporting student understanding. The results of this research could lead to the further development and refinement of screencasts on DC resistive circuits and also useable guidelines in creating innovative screencasts on DC resistive circuits. / MEd (Curriculum Development), North-West University, Potchefstroom Campus, 2014
49

Misconceptions regarding direct-current resistive theory in an engineering course for N2 students at a Northern Cape FET college / Christiaan Beukes

Beukes, Christiaan January 2014 (has links)
The aim of this study is to ascertain what misconceptions N2 students have about DC resistive circuits and how screencasts could effect on the rectification of these misconceptions. This study was conducted at the Kathu Campus of the Northern Cape Rural Further Education and Training College in the town Kathu in the arid Northern Cape. The empirical part of this study was conducted during the first six months of 2013. A design-based research (DBR) method consisting of four phases was used. DBR function is to design and develop interventions such as a procedure, new teachinglearning strategies, and in the case of this study a technology-enhanced learning (TEL) tool (screencast) with the purpose of solving a versatile didactic problem and to acquire information about the interventions of the TEL tool (screencast) on the learning of a student. In the first and second phase of DBR quantitative data for this research were gathered with the Determining and Interpreting Resistive Electric circuits Concepts Test (DIRECT) in order to determine the four most common misconceptions. The DIRECT test was conducted in the first trimester to find the misconceptions; the test was conducted in the second trimester also to confirm the misconceptions. Further quantitative data were collected from a demographic questionnaire. The qualitative data were collected by individual interviews in the fourth phase of the research project. Phase three of this study was the development of screencasts in the four most prominent misconceptions in DC resistive circuits of the students. The respondents of this study were non-randomly chosen and comprised of two groups, one in the first trimester of the year and one in the second trimester of the year, which enrolled for the N2 Electrical or Millwright courses. The respondents were predominant male and representing the three main cultural groups in the Northern Cape namely: Black, Coloured and White. The four misconceptions on DC resistive circuits that were identified were: (i) understanding of concepts, (ii) understanding of short circuit, (iii) battery as a constant current source, and (iv) rule application error. Screencasts clarifying the four misconceptions were developed and distributed to the respondents. On the foundation of the results of this research, it can be concluded that the students have several misconceptions around direct current resistive direct current circuits and that the use of TEL like screencasts can be used to solve some of these misconceptions. Screencasts could supplement education when they were incorporated into the tutoring and learning for supporting student understanding. The results of this research could lead to the further development and refinement of screencasts on DC resistive circuits and also useable guidelines in creating innovative screencasts on DC resistive circuits. / MEd (Curriculum Development), North-West University, Potchefstroom Campus, 2014
50

Modelování prvků pro bioelektroniku / Modelling of bioelectronic devices

Truksa, Jan January 2018 (has links)
Tématem této práce je počítačové modelování organického elektrochemického tranzistoru (OECT). Pro vytvoření modelu bylo třeba vypočítat rozložení elektrického pole a koncentrace iontů elektrolytu. Výpočet byl proveden numericky pomocí metody konečných prvků. Bylo vypočítáno rozložení elektrického potenciálu na povrchu kanálu OECT, dále byly vypočítány změny vodivosti a výstupní proud OECT. Výpočty byly provedeny na osobním počítači pomocí komerčního softwaru COMSOL Multiphysics. Kvůli nedostatečnému výpočetnímu výkonu musel být model rozdělen na části a drasticky zjednodušen. Prezentované výsledky se liší od literatury, protože se nepodařilo správně modelovat saturaci tranzistoru. Odchylky od reálného chování OECT jsou pravděpodobně způsobeny zjednodušením modelu.

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