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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

Studium vnitřního odporu článku olověného akumulátoru pro hybridní elektrická vozidla / Study of internal resistance of the lead acid battery cell for hybrid electric vehicles

Vojtíšek, Miloš January 2013 (has links)
This work aims on acumulators for hybrid vehicles and deals particularly with research of inner-resistance of the lead-acid batteries. There is a brief characterization of hybrid cars in first part of the tesis. Second part is dealing with design of experimental measurement setup for measurement of lead-acid electrochemical cells. Set of experiments on several cells was performed, description of experiments and results in graphical form are present.
32

Zkoumání vlivu oxidu titaničitého na životnost olověných akumulátorů s aplikovaným přítlakem / Influence of titanium dioxide on the life of lead acid batteries with applied pressure

Řihák, Pavel January 2013 (has links)
Hybrid electric vehicles use lead acid batteries operating under partial charge. Battery life of these batteries is dependent on the speed of development of lead sulphate (PbSO4) to the negative electrodes. Different admixtures are affected battery life. This work deals with the influence of titanium dioxide on the negative active material in lead battery. Mainly devoted to the influence of the applied pressure.
33

Minimising Battery Degradation And Energy Cost For Different User Scenarios In V2G Applications : An Integrated Optimisation Model for BEVs

Bengtsson, Jacob, Moberg Safaee, Benjamin January 2023 (has links)
The functionality to both charge and discharge energy from and to the power grid to a Battery Electric Vehicle (BEV) is referred to as Vehicle-to-Grid (V2G). This allows the customer to buy energy when the spot price is low and sell energy when the price is high to make a profit, called energy arbitrage. However, when the battery is charging, discharging, or idling for storage, battery degradation occurs due to chemical properties and reactions. This thesis developed a mathematical optimisation model in Python, using the modelling language Pyomo. Mathematical equations are used to integrate energy arbitrage and degradation data to reduce the total cost in terms of degradation and energy by finding an optimised charge and discharge pattern. The model allows different user scenarios to be analysed by changing inputs such as charger power, battery cost or daily driving distance. When using V2G technology, the State-of-Charge (SoC) level of BEVs battery packs can be adjusted to find SoC levels which minimise the battery degradation, while allowing the user to make a profit from energy arbitrage. The result shows that the V2G charging protocol, compared to protocols without a bidirectional charger could be beneficial for the simulated time periods, by both reducing degradation and the total energy cost. The results also indicate that the degradation cost of the battery is often the determining factor in the decision of when to charge or discharge, i.e., the substantial cost-saving strategy is to control the storage and cycle degradation to reduce the total degradation, rather than controlling the energy arbitrage. The model and the result of this thesis can be used by car manufacturers to learn more about how battery cell types behave in V2G mode and influence further work on V2G control.
34

Sizing Methodology and Life Improvement of Energy Storage Systems in Microgrids

Khasawneh, Hussam Jihad 19 May 2015 (has links)
No description available.
35

Enhanced Dielectric Properties of Multilayer Capacitor Film via Interfacial Polarization

Tseng, Jung-Kai 27 January 2016 (has links)
No description available.
36

超微細穴抜き用セラミック・ファイバ・パンチを電極とした超音波援用放電加工

森, 敏彦, 廣田, 健治 05 1900 (has links)
科学研究費補助金 研究種目:基盤研究(C) 課題番号:17560095 研究代表者:森 敏彦 研究期間:2005-2006年度
37

Problèmes de placement, de coloration et d’identification / On packing, colouring and identification problems

Valicov, Petru 09 July 2012 (has links)
Dans cette thèse, nous nous intéressons à trois problèmes issus de l'informatique théorique, à savoir le placement de formes rectangulaires dans un conteneur (OPP), la coloration dite "forte" d'arêtes des graphes et les codes identifiants dans les graphes. L'OPP consiste à décider si un ensemble d'items rectangulaires peut être placé sans chevauchement dans un conteneur rectangulaire et sans dépassement des bords de celui-ci. Une contrainte supplémentaire est prise en compte, à savoir l'interdiction de rotation des items. Le problème est NP-difficile même dans le cas où le conteneur et les formes sont des carrés. Nous présentons un algorithme de résolution efficace basé sur une caractérisation du problème par des graphes d'intervalles, proposée par Fekete et Schepers. L'algorithme est exact et utilise les MPQ-arbres - structures de données qui encodent ces graphes de manière compacte tout en capturant leurs propriétés remarquables. Nous montrons les résultats expérimentaux de notre approche en les comparant aux performances d'autres algorithmes existants. L'étude de la coloration forte d'arêtes et des codes identifiants porte sur les aspects structurels et de calculabilité de ces deux problèmes. Dans le cas de la coloration forte d'arêtes nous nous intéressons plus particulièrement aux familles des graphes planaires et des graphes subcubiques. Nous montrons des bornes optimales pour l'indice chromatique fort des graphes subcubiques en fonction du degré moyen maximum et montrons que tout graphe planaire subcubique sans cycles induits de longueur 4 et 5 est coloriable avec neuf couleurs. Enfin nous confirmons la difficulté du problème de décision associé, en prouvant qu'il est NP-complet dans des sous-classes restreintes des graphes planaires subcubiques.La troisième partie de la thèse est consacrée aux codes identifiants. Nous proposons une caractérisation des graphes identifiables dont la cardinalité du code identifiant minimum ID est n-1, où n est l'ordre du graphe. Nous étudions la classe des graphes adjoints et nous prouvons des bornes inférieures et supérieures serrées pour le paramètre ID dans cette classe. Finalement, nous montrons qu'il existe un algorithme linéaire de calcul de ID dans la classe des graphes adjoints L(G) où G a une largeur arborescente bornée par une constante. En revanche nous nous apercevons que le problème est NP-complet dans des sous-classes très restreintes des graphes parfaits. / In this thesis we study three theoretical computer science problems, namely the orthogonal packing problem (OPP for short), strong edge-colouring and identifying codes.OPP consists in testing whether a set of rectangular items can be packed in a rectangular container without overlapping and without exceeding the borders of this container. An additional constraint is that the rotation of the items is not allowed. The problem is NP-hard even when the problem is reduced to packing squares in a square. We propose an exact algorithm for solving OPP efficiently using the characterization of the problem by interval graphs proposed by Fekete and Schepers. For this purpose we use some compact representation of interval graphs - MPQ-trees. We show experimental results of our approach by comparing them to the results of other algorithms known in the literature. we observe promising gains.The study of strong edge-colouring and identifying codes is focused on the structural and computational aspects of these combinatorial problems. In the case of strong edge-colouring we are interested in the families of planar graphs and subcubic graphs. We show optimal upper bounds for the strong chromatic index of subcubic graphs as a function of the maximum average degree. We also show that every planar subcubic graph without induced cycles of length 4 and 5 can be strong edge-coloured with at most nine colours. Finally, we confirm the difficulty of the problem by showing that it remains NP-complete even in some restricted classes of planar subcubic graphs.For the subject of identifying codes we propose a characterization of non-trivial graphs having maximum identifying code number ID, that is n-1, where n is the number of vertices. We study the case of line graphs and prove lower and upper bounds for ID parameter in this class. At last we investigate the complexity of the corresponding decision problem and show the existence of a linear algorithm for computing ID of the line graph L(G) where G has the size of the tree-width bounded by a constant. On the other hand, we show that the identifying code problem is NP-complete in various subclasses of planar graphs.
38

Vliv iontů manganu ve struktuře hydroxidu nikelnatého na vlastnosti elektrod / Influence of Mn ionts in nickel hydroxide on behavour electrodes

Cirkovský, Jaroslav January 2010 (has links)
The aim of my diploma thesis was to explore the influence of manganese ions put into nickel nitrate structure. The attention was focused mainly on the stabilization of nickel nitrate a modification, which could not change into b modification. The theoretical part of my thesis focused on applied materials, kinds of acumulators, basic parameters of acumulators and the description of chosen methods of measurement employed. It contained the electrodeposition, the impedance spectroscopy and the cyclic voltammetry. The task of the experimental part was to measure the effect of manganese ions put into potassium hydroxide structure. Proportions of Ni (nickel nitrate) : Mn (manganese nitrate) 10:0, 7:3, 5:5, 6:1 and 6:4 were blended for the measurement. By means of the electrodeposition, there was a thin layer of nickel hydroxide with an admixture of manganese ions from nickel nitrate and manganese nitrate dilution put on the nickel plate. After the spread of the thin layer on the nickel plate, the measurement by the method of cyclic voltammetry followed. The next task consisted in trying to add KOH (potassium hydroxide) anionic and cationic surfactant into the dilution.
39

Vliv oxidu titaničitého na vlastnosti olověných akumulátorů pracujících v režimu hybridních vozidel / Effect of titanium dioxide on the properties of lead-acid batteries operating in hybrid vehicles mode

Konečný, Zdeněk January 2012 (has links)
This work deals with lead-acid batteries operating in hybrid electric vehicles mode, i.e. in a partial state of charge. The adverse effects such as premature capacity loss and large internal resistance can markedly affect the life of a lead battery. The experiment described in this work aims to clarify the influence of the titanium dioxide in the active mass of negative electrodes especially in the life of lead acid batteries.
40

Vliv přítlaku na životnost olověných akumulátorů u hybridních elektrických vozidel / Exploring the influence of pressure on the life of lead acid batteries for hybrid electric vehicles

Pospíchal, Martin January 2012 (has links)
The lead-acid batteries used in hybrid electronic vehicles HEV operate in high-rate mode in a state of partial charge PSoC. It occurs when the degradation mechanisms related to irreversible sulphation and negative electrodes are a limiting factor in the life of lead-acid batteries. The electrode system was applied to experimental pressure cells of different sizes. Exp. cells were subjected to measurement and evaluation of potential negative electrode, a negative active mass resistance, contact resistance of transition collector - the active mass with the evaluation and measurement of pressure fluctuations within four PSoC runs.

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