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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.
561

Modifikace měřicího pracoviště pro měření solárních článků / Modification of measurement workplace for solar cells

Roček, Radovan January 2009 (has links)
The problems of solar cells are described in general in theoretic part of the master’s thesis. In particular there is described structure of solar cells, procedure of production of solar cells, kinds of defects that can occur in solar cells and diagnostic methods of detection of this defects. The solar simulator, electroluminescence method, detection of defects during microplasma shining, LBIV and LBIC method belongs to category of diagnostic methods. The main focusing is on diagnostic method of LBIC (Light Beam Inducted Current). The workplace which exploits this method is used in laboratory in Department of Electrotechnology on University of Technology Brno. This method is very exact and it reveals most of defects in solar cell but the problem is the slow speed of testing. In practical part of the master’s thesis the main solved problem is the proposition and realization of modified workplace of LBIC that would work on more modern level, it means using performer PC for service program and Agilent 34410A the modern measuring device. The speed up of the testing time is the goal of modernization in existing accuracy of finding. The modify workplace is realized and compared with the existing workplace subsequently.
562

Charakterizace zadních stran solárních článků / Characterization backsides of solar cells

Winkler, Luděk January 2010 (has links)
This thesis deals with the characterization back side of solar cells. In order to describe the quality of material from the point of view of a back side solar cell, the method of photoluminescence, the method of light emitting from micro plasma and LBIC (Light Beam Induced Current) is used. Gained results are compared with the results of front side analysis. Next, the thesis describes back side potential.
563

Využití oxidu yttria pro vytváření antireflexních vrstev solárních článků / Yttrium oxide layers for antireflection coating of silicon solar cells

Dostál, Vladimír January 2010 (has links)
This work deals with deposition of yttrium oxide layers on silicon substrate (P – type) by using magnetron and reactive magnetron sputtering. Experiments which were made are further described. After that, work is focused on evaluation of deposited layers by using FTIR measurement technique and spectrophotometry. At the end of the work results of experiments are discussed also with the future progress.
564

Vývoj fukčních bloků pro autonomní fotovoltaický systém / Functional blocks for the development of autonomous photovoltaic system

Ovesný, Karel January 2011 (has links)
The project considers realization system, which will allow us to test six different operation modes on lifetime accumulators. The system will link to computer, which will execute measurement current and tension and switch betwencharging and discharging modes. The measured values will record in someone time intervals in to computer memory. After someone time will analise these measured valuer and will provide optional operation mode.
565

Automatické měřicí pracoviště U-I charakteristik solárních článků / V-I characteristic of solar cells

Kaderka, Tomasz January 2011 (has links)
The theoretical part is to outline the possibilities of solar energy conversion, learn about the issues solar cells and describe the history of photovoltaics and photovoltaic energy conversion. Then describe principle of the measurement VA characteristics of photovoltaic cells. This issue is not as easy as it seems at first sight, because the solar cell isn’t a linear component, which is very easy to measure. Analysis of VA characteristic of photovoltaic cells affects parameters such as: light intensity, temperature, serial and parallel resistance, the slope of the light source, and more. The practical part deals with creating a workplace for automatic measurement of VA characteristics of photovoltaic cells in the LabVIEW. Challenge is to create a functional program, which automatically measures the VA characteristics not only in the lighted cells, but also in the shaded cell (diode mode). The program calculates the power and important parameters, such as short-circuit current, open circuit voltage, maximum power, current and voltage at maximum power article. The program allows you to export the measured values to a text file. In the last chapter of this work is made control measurements of three samples of monocrystal photovoltaic cell by the measuring workplace. The measurement is compared with the reference device Solar Cell Tester.
566

Systém včasné výstrahy před lokální povodní / Local flood early warning system

Svoboda, Luděk January 2012 (has links)
The aim of this Master's thesis is to design a local flood warning system. The system consists of two basic types of units. The first unit is placed in the field usingsensors and evaluates the presence of water in an otherwise dry area. In the event of flooding sends a warning message using wireless technology. The second unit evaluates the warning messages and informs the personabout the situation via text messaging. Outdoor equipment is fullyautonomous and permanently placed in an outdoor environment. The system is designed based 8-bit microcontrollers. The main parametersinclude low power devices, mechanical durability and reliability.
567

Využití měřicí metody SPM v technologii výroby krystalických solárních článků / The Use of AFM Measurement Method in Crystalline Silicon Solar Cells Technology

Mojrová, Barbora January 2013 (has links)
This thesis deals with the use of Atomic Force Microscopy (AFM) and Kelvin Probe Force Microscopy (KPFM) in solar cells production. Both techniques measure surface properties using interactions between surface and tip that progressively scans entire surface of the sample. Atomic force microscopy allows three dimensional imaging of surface structure. Kelvin probe force microscopy is used to measure the contact potential difference on the sample surface. There are described experimental measurements of monocrystalline and multicrystalline substrates after various etching processes using AFM. By using KPFM the contact potential difference was measured on dielectric layers PSG, SiOX, SiNX and Al2O3 and on selective emitter structures. All experiments described in this work were carried out at the Solartec Ltd. workplace and they completely correspond with the actual technology of crystalline solar cells production.
568

Dlouhodobé sledování parametrů fotovoltaických panelů / Long-term monitoring of parameters of photovoltaic modules

Kladiva, Roman January 2013 (has links)
This thesis deals with the influence of degradation mechanisms to change the parameters of photovoltaic panels. The aim of the study was the long-term monitoring of selected solar modules, comparing their parameters with measurements from previous years and the evaluation of degradation mechanisms on their properties. The theoretical part is focused on the description of the monitored parameters and defects Panel, are discussed measuring methods by which the modules were monitored. Experimental part then consists of measuring modules individual test methods. The measured values were subsequently constructed graphical dependence, and the results were compared with measurements from previous years. The last part of the thesis is devoted to evaluation of the degradation of PV modules.
569

Process development and scale-up for low-cost high-efficiency kesterite thin film photovoltaics / Développement des procédés et mise à l'échelle pour le photovoltaïque à couche mince à faible coût et à haute efficacité en kerterite

Vauche, Laura 27 November 2015 (has links)
Dans un contexte général d’augmentation de la demande énergétique et de préoccupation croissante face au réchauffement climatique et à la limitation des ressources naturelles, l’utilisation d’énergie solaire devrait augmenter. L’avenir des différentes technologies photovoltaïques dépend évidemment de leur rendement de conversion photovoltaïque et de leur coût mais aussi de la disponibilité des ressources. Les couches minces de kesterite, Cu2ZnSnS4 (CZTS), Cu2ZnSnSe4 (CZTSe) ou Cu2ZnSn(S,Se)4 (CZTSSe), composées d’éléments abondants dans la croûte terrestre se positionnent en candidat prometteur pour la conversion d’énergie solaire à grande échelle.Dans cette thèse, l’électro-dépôt, un procédé compatible avec des exigences industrielles de production, est utilisé pour déposer un précurseur de cuivre, étain et zinc sur des substrats de 15 × 15 cm2, de composition et épaissseur contrôlables. Ce précurseur est ensuite converti en semiconducteur par traitement thermique en présence de soufre ou de sélénium. Les couches ainsi formées de Cu-Zn-Sn-S ou Cu-Zn-Sn-Se, doivent être uniformes et présenter les propriétés appropriées (phases, composition, morphologie) pour la fabrication de cellules solaires à haut rendement. Le procédé de fabrication de la cellule solaire complète, notamment les étapes qui interviennent dans la formation de la jonction p-n (décapage chimique et dépôt de couche tampon) est également optimisé pour maximiser les rendements. A l’issue de ces optimisations, un rendement de 9.1% est obtenu pour une cellule solaire CZTSe, un nouveau record pour les cellules solaires à base de kesterite fabriquées par électro-dépôt. / Facing growing energy demand and increasing concerns about climate change and finite energy sources, solar energy use should increase. The future of the different photovoltaic technologies obviously depends on their power conversion efficiency and cost (summarized by the ratio cost per watt), but also on the elements availability. Thin films of earth-abundant kesterite, Cu2ZnSnS4 (CZTS), Cu2ZnSnSe4 (CZTSe) or Cu2ZnSn(S,Se)4 (CZTSSe), which can be manufactured with low-cost processes, are promising candidates for solar energy conversion at large scale.In this thesis, a copper tin and zinc precursor of controllable composition and thickness is electrodeposited on 15 × 15 cm2 substrates. Electrodeposition is a process compatible with high throughput low-cost and safety industry requirements. The precursor is converted into a semiconductor by thermal treatments in presence of sulfur or selenium. The resulting Cu-Zn-Sn-S or Cu-Zn-Sn-Se layers should be uniform and have adequate properties (phases, composition and morphology) to produce high efficient solar cells. Full device processing, including the pn junction formation steps (wet chemical etching and buffer layer deposition) is also investigated in order to maximize device efficiency. The best CZTSe solar cell exhibits a 9.1% powerconversion efficiency, setting a new record for kesterite solar cells produced by electrodeposition.
570

Obnovitelné zdroje energie jako námět pro fyzikální experimenty / Renewable Energy Sources as Inspiration for Physics Experiments

Kopřiva, Tomáš January 2018 (has links)
Title: Renewable Energy Sources as Inspiration for Physics Experiments Author: Bc. Tomáš Kopřiva Department: Department of Physics Education Supervisor: RNDr. Petr Kácovský, Ph.D. Abstrakt: This thesis deals with a current issue of renewable resources of energy. It focuses on the Sun, wind and hydrogen as energy resources.The first part of the thesis provides a theoretical explanation to these resources and is followed by a practical part with the aim to explain this issue to students by using experiments included in worksheets. The theoretical part is focused on the minimal knowledge that is needed for completing the worksheets. This part also describes suitability of these resources in the context of the Czech Republic. The second part of the thesis is exclusively experimental. It describes educational kits that can be used to demonstrate renewable resources of energy. It also includes instructions to create worksheets. The attachment, which is part of the thesis, contains a set of worksheets and a CD which, among others, contains other worksheets filled in by students. Key words: renewable resources, worksheet, experiment, solar cell, fuel cell, wind turbine, efficiency

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