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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.
1

Commensurabilities of planetary orbits

Melita, Mario Daniel January 1996 (has links)
No description available.
2

Podnikatelský plán pro vybranou firmu / Business plan for the selected company

Bürgerová, Jana January 2011 (has links)
As a topic of my thesis I chose to prepare a business plan for the company HOMEPLUS Service Ltd. HOMEPLUS is a small service company, which at the moment has been going through a substantial restructuring and has been looking for a new potential on the market by supplementing the current range products by a new assortment. At this point, is divided into two sections: gastro and solar systems. Within the section gastro supplies and installs all the equipment for restaurants, especially draft equipments. In the section of solar systems, has been newly trying to promote the sale and installation of solar heating systems and other equipment. The aim of this work was to prepare a real business plan for 2012 for this company which will be applied in practice by the company owner. The work is divided into two parts. The first part is devoted to theory. The second part include real business plan for 2012 for the company Homeplus Service Ltd.
3

Consequences of Nordic Conditions on the Performance of Large-Scale Building Applied PV Installations

Kurdia, Ali January 2017 (has links)
This thesis aimed for a better understanding of the Nordic weather conditions in terms of snow induced soiling on the performance and production of an established photovoltaic plant located on the roof of Økern nursing home, Oslo. In order to realize the main aim, several steps had to be done in preparation of the main analysis, these steps in fact are as important to this thesis as the main deliverable. The search for appropriate meteorological data proved to be not an easy task because of the scarcity of ground measurement stations, and the high inaccuracies in satellite observations. After analyzing all the sources with available data for the region of Oslo, three sources of data were chosen based on comparisons to an onsite set of reference measurements, these are the Blindern meteo station, the NASA SSE satellite derived observations, and the STRANG data base. A model of the actual system was created in PVsyst, exceptional attention to the level of detail was exercised in order to approach the case of eliminating any source of variation in the simulated models other than the required study parameter, the soiling. Simulations of many system variants ultimately resulted in the aggregation of a soiling loss profile to be used in conjunction with each of the meteo sources to predict the snow induced soiling consequences on the system. The soiling loss profiles were tested and the results compared to actual system production measurements, and it was successful in introducing the correction the model needed to simulate the system closely to reality. However, absolute change in production figures is relatively small, therefore, this study and any future continuation of it is oriented into research and improvement as it possess minimal impact on a commercial application.
4

Využití změny skupenství při akumulaci tepla v solárních vzduchových systémech / Latent heat thermal storage in solar air systems

Súkup, Tomáš January 2012 (has links)
In this paper an overview is prepared for the possibility of heat accumulation in the use of heating and hot water. In the next section is designed heat accumulator uses PCM materials for solar air system. Its properties are experimentally verified.
5

ENERGY ANALYSIS OF A SOLAR BLIND CONCEPT INTEGRATED WITH ENERGY STORAGE SYSTEM

Niaparast, Shervin January 2013 (has links)
The use of an attached sunspace is one of the most popular passive solar heating techniques. One of the main drawbacks of the sunspace is getting over heated by the sun energy during the hot season of the year. Even in northern climates overheating could be problematic and there is a considerable cooling demand. Shading is one of the most efficient and cost effective strategies to avoid overheating due to the high irradiation especially in the summer. Another strategy is using ventilation system to remove the excess heat inside the sunspace. However this rejected energy can be captured and stored for future energy demands of the sunspace itself or nearby buildings. Therefore the Solar blind system has been considered here for the shielding purpose in order to reduce the cooling demand. By considering the PV/T panels as the solar blind, the blocked solar energy will be collected and stored for covering part of the heating demand and the domestic hot water supplies of the adjacent building.  From a modeling point of view, the sunspace can be considered as a small-scale closed greenhouse. In the closed greenhouse concept, available excess heat is indeed utilized in order to supply the heating demand of the greenhouse itself as well as neighboring buildings. The energy captured by PV/T collectors and the excess heat from the sunspace then will be stored in a thermal energy storage system to cover the daily and seasonal energy demand of the attached building. In the present study, a residential building with an attached sunspace with height, length and width of 3, 12 and 3.5 meters respectively has been assumed located in two different locations, Stockholm and Rome. Simulations have been run for the Solar blind system integrated with a short-term and a long-term TES systems during a year to investigate the influence of the sunspace equipped with a PV/T Solar blind on the thermal behavior of the adjacent building. The simulated results show that the Solar blind system can be an appropriate and effective solution for avoiding overheating problems in sunspace and simultaneously produce and store significant amount of thermal energy and electricity power which leads to saving considerable amount of money during a year.
6

Změny antikorozního systému nemrznoucích teplonosných kapalin / Changes anticorrosive system non - freezing heat transfer liquid

Pexa, Michal January 2008 (has links)
This diploma thesis is focused on proposition of non-freezing heat transfer fluid for solar systems. Fluid will be based on mixture of new available compound propane-1,3-diol with water and modern corrosion inhibitors. Then will be investigate, if this new compound is competetive to common used liquids like ethylene glycol or propylene glycol.
7

Fyzikálně-chemické aspekty ekologických teplonosných kapalin / Physicochemical Aspects of Ecological Heat-transfer Fluids

Skolil, Jan January 2016 (has links)
This thesis develops composition of heat transfer fluids with antifreeze properties next to traditional one component glycols produced from propene and ethene. Based on assessment of physical properties it considers application of progressive antifreeze compounds of glycerine and propan-1,3-diole and their mixtures with classic glycols, which do not have negative influence on the environment and which are produced in last years from renewable sources. Due to the necessity of selection of certain compromise between their heat transfer properties, price, solubility and other factors physical properties of selected mixtures are determined together with synergy of each compound, including formulas with glycols: ethan 1,2 diol and propan 1,2 diol Another evaluated factor of studied formulations in addition to their heat transfer properties was anticorrosive protection of common corrosion inhibitors mixtures. The result of whole work is the proposal of several most perspective formulations based on mixtures of polyhydric alcohols in terms of their features enabling them heat transfer, reasonable costs, and the restrictions of impact of their use, particularly in heat transfer systems, to human health and the environment. The knowledge of physical properties of water solutions of polyhydric alcohols mixtures also helps to better using of recycled materials from planning recycling plant for glycols.
8

Contribution au pré dimensionnement et à l'optimisation des sites de production d'énergie électrique en site isolé à partir des énergies renouvelables : application au cas du Laos / Contribution to the pre-sizing and in the optimization of electric power production in isolated site using renewable energies : application in the case of Laos

Phrakonkham, Sengprasong 13 July 2012 (has links)
Depuis 2004, l'Université de Paris Sud a établi une collaboration avec le département de Génie Électrique de la Faculté d'ingénierie de l'Université du Laos (UNL). La thématique de recherche concerne le pilotage de l'électronique de puissance pour la gestion de sources d'énergie renouvelable pour le Laos. Ainsi en 2009, le Gouvernement français a financé une bourse de thèse pour le développement d'un outil de pré-dimensionnement de la production électrique renouvelable pour les villages isolés au Laos. En effet, le réseau de transport et de distribution du Laos est déjà en tension compte tenu de l'explosion de la consommation dans les zones urbaines. Son extension aux zones rurales notamment dans les zones montagneuses représente un coût d'investissement beaucoup trop élevé. Par contre le pays bénéficie de ressources naturelles (hydrauliques, solaire et agricoles) dont l'exploitation judicieuse peut permettre le développement de la filière des énergies renouvelables. La production d'énergie électrique décentralisée (fermes solaires par exemple) nécessite une évaluation des ressources locales et un dimensionnement optimal de l'ensemble des constituants (sources, dispositifs de stockage, convertisseurs, etc.) et de l'architecture du mini ou micro réseau autonome.Cette thèse est organisée en 3 chapitres :Le chapitre 1 présente dans un premier temps le travail qui permit d'identifier les besoins et les ressources effectivement disponibles au Laos. Pour cela, un séjour de plusieurs semaines dans des zones rurales reculées du Nord-Ouest du Laos a été effectué. Cela a permis d'obtenir un profil de consommation standard, d'identifier les ressources et de relever les données des réseaux rudimentaires existants (puissance et configuration). Une importante recherche bibliographique sur les outils logiciels existants a ensuite été réalisée. Cela a permis de dimensionner et de simuler ces systèmes autonomes. Le chapitre 2 présente les limitations de ces outils de conception (absence de flexibilité dans les modèles utilisés et algorithmes d'optimisation trop contraints) et le développement dans l'environnement de Matlab-Simulink d'une bibliothèque de modèles des constituants du système d'énergie autonome. Les modèles sont réalisés pour faciliter un dimensionnement optimal du système selon des critères de coût, de disponibilité et de fiabilité. Un important travail d'étude bibliographique sur les architectures de réseaux a été réalisé et combiné à une synthèse des ressources et des besoins des milieux ruraux au Laos. Le chapitre 3 présente deux exemples de dimensionnement de systèmes de production d'électricité pour des sites isolés au Laos à partir d'énergie renouvelables. Le cahier des charges correspond à un village isolé de 50 maisons pour 130 habitants. Le critère économique est fondamental dans cette étude où l'optimisation cherche à réduire les coûts des constituants tout en satisfaisant les besoins en puissances des villageois. Différentes optimisations continue et hybrides (continu et entier) sont conduites en tenant compte de contraintes sur les sources. Des indicateurs de performance sont ainsi utilisés: "Loss of Power Supply Probability, Forced Outage Rates, Annualized Cost of System, Levelized Cost of Energy, etc.". / Since 2004, a collaboration between Université Paris Sud of France and the Department of Electrical Engineering Faculty of Engineering, National University of Laos (NUOL) has been carried out on the control of power electronics for the management of renewable energies source in Laos. Therefore in 2009, the French Government has funded a PhD thesis on the development of a designing tool for the early-sizing of renewable electricity production for isolated villages in Laos. This thesis report is organized in three chapters:Chapter I presents a short review of the status and development plans for the electrification of Laos. Then, based on a two-month field study in Northern Laos, analyses of energy consumptions of households in isolated villages and available renewable sources, using small scale hydro power plants and solar systems among others, are presented. Afterward, micro-grid configurations and technologies adapted to Laos are discussed. Obtained results are used in the next chapters as specifications for the designing tool.Chapter II focuses on software tools for system design and system modeling. First, a short review of the existing early-sizing tools for renewable energy sources for isolated villages is presented. But an analysis of evaluated software's such as LEAP, HOMER, HOGA, etc. shows that they are not opened enough to facilitate the development of a flexible and scalable designing too. Thus, Matlab/Simulink software is chosen as an open and highly adaptable architecture research tool. Then, specific models for renewable sources, storage devices, grid configuration are developed in order to facilitate the optimization procedures of an off-grid system design. After that, a short review of the existing optimization algorithms, available in Matlab, is carried out. Then, a paralleled mono-objective Genetic Algorithm is configured and applied in the next chapter.Chapter III presents several designs of isolated villages in Laos, using renewable energies. The specifications focus on isolated villages of about 50 houses for 120 inhabitants. The economic aspect is a key point in order to minimize costs of designed system while satisfying daily load demands of the village. For this task, locally available natural resources such as rivers and solar radiation are considered as energy sources. Various optimizations using continuous and discrete optimization algorithms are conducted taken into account the sources constraints and a short review of the existing hybrid system performance indicators is carried out, such as: Loss of Power Supply Probability, Forced outage rates, Annualized Cost of System, Levelized Cost of Energy, etc. Finally, the results obtained in this thesis show that renewable sources can be used at a reasonable price for off-grid electrification of isolated villages in Laos. Moreover, the developed designing tool can easily be adapted to new models of renewable sources and storage devices, which is the main interest of a designing tool for the early-sizing of off-grid renewable electricity production for isolated villages in Laos.
9

Využití solární energie v cestovním ruchu v Pardubickém kraji / Utilization of solar energy in the tourism sector in Pardubice region

VÍŠKOVÁ, Markéta January 2009 (has links)
The thesis is aimed at just one area of alternative energy sources. Its main goal is the analysis of the utilization of solar energy in Pardubice region. The main following themes are discussed: the current legislative background renewable resources, the posibility of obtaining funds from European and national funds or the properties and use of solar energy. On the basis of research results to be presented several proposals, which should contribute to increasing the attractiveness of solar systems.
10

Optimalizace provozu solárního systému určeného k ohřevu TUV školní jídelny / Optimization of the solar system designed for DHW school canteens heating

Doskočil, Filip January 2016 (has links)
Masters’s thesis describes the use of solar energy for solar thermal systems used for domestic hot water heating. It is about the size of the incident solar radiation on Earth. Distributes various types of solar collectors for water heating. It deals with the monitoring, remote management of this system and the design of optimal control used in this area.

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