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[en] PROTECTION OF FIXED-SATELLITE SERVICE NETWORKS THAT USE GEOSTATIONARY SATELLITES FROM THE INTERFERENCE GENERATED BY THE DOWN-LINKS OF NON-GEOSTATIONARY SATELLITE SYSTEMS OPERATING IN THE 3.7-4.2 GHZ BAND / [pt] PROTEÇÃO DE REDES DO SERVIÇO FIXO POR SATÉLITE QUE UTILIZAM SATÉLITES GEOESTACIONÁRIOS CONTRA A INTERFERÊNCIA GERADA PELOS LANCES DE DESCIDA DE SISTEMAS NÃO GEOESTACIONÁRIOS OPERANDO NA FAIXA 3,7-4,2 GHZRAINEL SANCHEZ PINO 30 January 2019 (has links)
[pt] Neste trabalho, limites para a densidade de fluxo de potência equivalente produzida pelos lances de descida de sistemas de satélites nãogeoestacionários (não-GEO), operando na faixa de 3,7-4,2 GHz, são analisados. Estes limites visam proteger os receptores do Serviço Fixo por Satélite (FSS) das interferências produzidas por sistemas de satélites não geoestacionários, quando ambos operam na faixa de frequências considerada. A analise destes limites foi motivada pela Resolução 157 da Conferência
Mundial de Radiocomunicações de 2015 (WRC-15), que ressalta a necessidade de estudos envolvendo aspectos técnicos e operacionais relativos à operação de sistemas não-GEO operando na faixa de frequências de 3,7 - 4,2 GHz de modo a permitir que esses sistemas possam operar nestas faixas de frequências assegurando, ao mesmo tempo, que os serviços primários existentes, entre eles o FSS, continuem protegidos. A importância do assunto fez com que este tópico fosse incluído na agenda da WRC-19. No trabalho, é inicialmente desenvolvida uma metodologia para a determinação de máscaras limitantes para a densidade de fluxo de potência equivalente produzida pelos lances de descida (epfd(descida)) de sistemas de satélites não-GEO. Esta metodologia foi utilizada na obtenção de duas máscaras baseadas, respectivamente, nos critérios de proteção das recomendações ITU-R S.1323 e ITU-R F.1495. Uma análise comparativa das máscaras de epfd(descida) obtidas foi feita considerando-se cinco constelações de satélites não-GEO do tipo Walker Delta, escolhidas adequadamente para cobrir um amplo conjunto de possibilidades. A análise utilizou, como base, o comportamento estatístico das margens associadas a cada uma das máscaras de epfd(descida) propostas. / [en] In this work, the limits for the equivalent power-flux density produced by the down-links of non-geostationary satellite systems (non-GSO), operating in the 3,7-4,2 GHz band are analyzed. These limits aim the protection of Fixed-Satellite Service (FSS) receivers, from the interferences produced by non-geostationary satellite systems, operating in the same frequency band. The analysis of these limits was motivated by Resolution 157 of the 2015 World Radiocommunication Conference (WRC-15), that recognized the need for studies on technical and operational aspects related to the operation of non-GSO systems operating in the 3,7-4,2 GHz frequency band, so that these systems can adequately operate in these frequency band while ensuring, at the same time, that the existing primary services, among them the FSS, remain protected. Due to its importance the topic was included in the agenda of the WRC-19. In this work, a methodology for the determination of limiting masks for the equivalent power-flux density generated by the down-links (epfd(down)) of non-GSO satellite systems is initially developed. This methodology was used to obtain two mask based, respectively, on the protection criteria of the ITU-R S.1323 and ITU-R F.1495 recommendations. A comparative analysis of the two obtained epfd(down) masks was made considering five Walker Delta type non-GSO satellite constellation, appropriately chosen to cover a wide set of possibilities. The analysis used, as a basis, the statistic behavior of the margins associated to each of the proposed epfd(down) masks.
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[en] ON THE PROTECTION OF FIXED SERVICE RECEIVERS FROM THE INTERFERENCE GENERATED BY NON-GSO SATELLITE SYSTEMS OPERATING IN THE 3.7-4.2 GHZ BAND / [pt] PROTEÇÃO DE RECEPTORES DO SERVIÇO FIXO TERRESTRE DAS INTERFERÊNCIAS GERADAS POR SISTEMAS NÃO-GEO OPERANDO NA FAIXA DE 3.7-4.2 GHZISABELA CUNHA MAIA NOBRE 17 November 2017 (has links)
[pt] Neste trabalho, os limites atuais de densidade de fluxo de potência do Artigo 21 do Regulamento de Radiocomunicações da UIT para sistemas não-GEO operando na banda 3.7-4.2 GHz são analizados. Estes limtes visam proteger os receptores do Serviço Fixo Terrestre, operando na mesma faixa de frequência, das interferências produzidas por sistemas de satélites não geoestacionários. A análise foi motivada pela Resolução 157 [1] da Conferência Mundial de Radiocomunicações de 2015, que reconheceu a necessidade de uma revisão do Artigo 21 para que sistemas não-GEO possam operar nestas faixas de frequências assegurando, ao mesmo tempo, que os serviços primários existentes continuem protegidos. Na análise, cinco estruturas de constelações de satélites não-GEO do tipo Walker Delta, adequadamente escolhidas, foram consideradas. Resultados mostraram que os atuais limtes de pfd podem impor restrições indevidas aos sistemas não-GEO operando nesta faixa. Assim, uma metodologia para investigar uma máscara limitante de pfd mais adequada é apresentada. A aplicação desta metodologia leva a uma máscara alternativa que se aproxima dos limites atuais de pfd para satélites geoestacionários quando o número de satélites no sistema interferente não-GEO é igual a um. Uma avaliação da máscara de pfd proposta mostra que ela não impõe restrições desnecessárias aos sistemas de satélites não-GEO. Isto, junto a outros fatos, indica que os limites de pfd propostos são, de fato, muito mais adequados do que os atuais. / [en] In this work, the current power-flux density limits in Article 21 of the ITU-R Radio Regulations for non-GSO systems operating in the 3.7-4.2 GHz band are analyzed. These limits aim the protection of Fixed Service receivers, operating in the same frequency band, from the interference produced by non-GSO satellite systems. The analysis was motivated by Resolution 157 [1] of the World Radiocommunication Conference 2015, that recognized the need for a revision of Article 21 with a view to enabling non-GSO systems to operate in these FSS frequency bands while ensuring that existing primary services are protected. In the analysis, five different Walker Delta type satellite constellation structures, adequately chosen, were
considered. Results have shown that the current pfd limits may impose undue constraints to non-GSO systems operating in this band. Therefore, a methodology to investigate a more adequate pfd limiting mask is presented. The application of this methodology leads to an alternative mask that approaches the current pfd limits for the geostationary satellites when the number of satellites in the non-GSO interfering system is equal to one. An evaluation of the proposed pfd mask shows that it does not impose unnecessary constraints to the non-GSO satellite systems. This, along with other facts, indicates that the proposed pfd limits are, indeed, much more adequate than the current ones.
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Stínění a detekce neutronů / Shielding and detection of neutronsČerný, Tomáš January 2020 (has links)
The master’s thesis provides an overview of available neutron sources in terms of neutron yields and energy spectrum of emitted neutrons. Reactions of neutrons with matter, especially neutron scattering and radiation capture, are described. The possibilities neutron neutron detection and spectrometry are also described. The following experiment deals with a design of suitable shielding materials and the analysis of the moderated energy spectrum of neutron flux. The properties of the neutron field were measured using detection by activation. Subsequently, a simulation of the problem was performer in the MCNP program. In the end, the achieved results are compared and evaluated.
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Optimální využití energie a vody v aquaponické farmě / Resource optimisation in the indoor aquaponic farmOndruška, Vojtěch January 2020 (has links)
Energetická náročnost a ekonomická životaschopnost jsou často skloňované pojmy spojené s aquaponickým způsobem produkce potravin. Tato práce si klade za cíl nalézt opatření, která by zvýšila ziskovost podnikání v oblasti aquaponie a zároveň by snížila energetickou náročnost procesu a spotřebu dalších zdrojů. Součástí práce je následné ověření vybraných opatření na zkušební aquaponické farmě. K vyřešení otázky úspory energie a vody byly použity optimalizační metody vycházející z procesního inženýrství. Pro účely automatického monitoringu růstu rostlin, jakožto hlavního zdroje příjmů v aquaponii, byla využita technologie počítačového vidění. Za využití optimalizační metody zvané P-graph, integrace procesů a hledání procesních alternativ bylo nalezeno nejlepší možné uspořádání procesní sítě, které vykazovalo více než devítinásobný čistý roční příjem ve srovnání se současným uspořádáním procesních zařízení v aquaponické farmě. Dalších úspor energie a vody bylo dosaženo instalací reflexních fólií na okraje pěstebních boxů a dalším využitím odpadní vody z aquaponické části farmy v hydroponické sekci určené k pěstování sazenic. Tato opatření mohou napomoci aquaponickým farmám zvýšit konkurenceschopnost a snížit jejich dopad na životní prostředí.
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Řešení rozložení magnetického pole ve stejnosměrném stroji / Solution magnetic field distribution in DC machineHájek, Jan January 2012 (has links)
This thesis deals with distribution of magnetic fields in the DC machine. Part of this thesis is the introduction of DC machines, principles of operation and distribution of DC machines. There is also discussed electrically commutated motors. The thesis demonstrates the types of permanent magnets and their properties. Then there is an analysis of the magnetic field electrically commutated motor Atas Nachod in the Ansoft Maxwell. Using Ansoft Simplorer, switching is carried out of the engine. Another part of this work is the analysisthe magnetic field electrically commutated motor Atas Nachod for three types of slot of the stator of the engine. Here it is seen what impact the change has slot on the distribution of magnetic field in the EC motor. Finally, training is carried out measurements of electrically commutated motor BOYANG BY92BL48-4000-2200.
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Elektromagnetický tlumič / Electromagnetic damperMikyska, Jan January 2014 (has links)
This master´s thesis is focused on obtaining electrical energy from vibration control car using electromagnetic dampers. The primary use of the electromagnetic damper is the production of electrical energy, which can then be used to power electrical appliances in your car or battery charging. The thesis is divided into six main parts: a literature review of possible ways of getting electricity from the car damping, theoretical and mathematical analysis of problems, the choice of design with computational analysis of dampers and power calculation.
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Contribution à la conception silencieuse par démarches directe et inverse de machines synchrones à aimants permanents et bobinage dentaire / Contribution to permanent magnet synchronous machines quiet design with concentrated winding using inverses approachesLa Delfa, Patricio 15 December 2017 (has links)
Cette thèse porte sur la conception silencieuse par démarches inverses de machines synchrones à aimants permanents dotées de bobinages dentaires. Notre travail se focalise sur l’analyse des raies de forces radiales à l’origine du bruit magnétique. En premier lieu, un modèle direct électromagnétique, nous a permis de déterminer le spectre spatio-temporel de la force radiale dans l’entrefer. Ce dernier nous offre la possibilité d’obtenir pas à pas et de manière analytique l’induction radiale dans l’entrefer, résultat du produit de la force magnétomotrice totale et de la perméance d’entrefer globale. Plusieurs machines dotées d’un bobinage dentaire et distribué ont été évaluées, comparées à des simulations par éléments finis et corroborés par une analyse modale opérationnelle sur un prototype existant au laboratoire. Puis la démarche inverse de conception est abordée par le biais de deux outils « analytiques prédictifs » donnant les origines des ordres faibles spatio-temporels de la force radiale dans l’entrefer. Enfin, la résolution du problème inverse est conduite au moyen d’une boucle itérative d’optimisation donnant parmi un échantillon de solutions, une fonction de bobinage, visant à atténuer ou supprimer une raie potentiellement risquée en termes de nuisances acoustiques / This thesis deals the quiet design by inverses approaches of synchronous machines with permanent magnets concentrated windings. Our work focuses on the analysis of magnetic noise origin of air gap radial force orders. Firstly a direct electromagnetic model allowed us to determine the spatio-temporal spectrum of air gap radial pressure. The latter offers us the possibility of obtaining step by step and in an analytical way the radial induction in the gap, result of the product of the total magnetomotive force and global air gap permeance. Several machines equipped with a concentrated winding and distributed were evaluated, compared to simulations by finite elements and corroborated by an operational deflection shape on an existing prototype in the laboratory. In the second time two inverse approaches named predictive methodology identified the radial pressure low order origin. Finally, the resolution of the inverse problem is carried out by means of an iterative optimization loop giving among a sample of solutions, a winding function, aimed at attenuating or eliminating a potential risky line in terms of acoustic nuisances.
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Einfluss der Bekeimung auf die Qualität von schmelztexturierten YBCO-Hochtemperatur-SupraleiternBierlich, Jörg 16 April 2010 (has links) (PDF)
Die für technische Anwendungen attraktivsten Eigenschaften der Hochtemperatur-Supraleiter beruhen auf der Wechselwirkung der Materialien mit einem externen Magnetfeld. Für hochleistungsfähige Supraleiteranwendungen werden großvolumige Funktionselemente mit eindomänigem Magnetisierungsverhalten benötigt. Zur Vergrößerung der magnetischen Domäne schmelztexturierter YBa2Cu3O7-δ-Kompaktsupraleiter wurde anhand der Multi-Seeding-Technik, die Rekristallisation unter Verwendung mehrerer SmBa2Cu3O7-δ-Keimpräparate untersucht.
Als Schlüsseltechnologie zur Herstellung anwendungsorientierter Supraleitererzeugnisse wurde zu Beginn der Arbeit die Keimkristallherstellung optimiert. Gemäß den Zielvorgaben stehen zukünftig quasi-einkristalline Keimkörper definierter Form und Orientierung in hoher Stückzahl zur Verfügung.
Die Supraleiter betreffend ist es gelungen, für den wechselseitigen Abstand und die Ausrichtung der Keimpräparate ein Optimum zu finden sowie tolerierbare Winkel der Verschwenkung angrenzender Kristalle zu ermitteln. Es wurde festgestellt, dass das Auftreten isolierender Korngrenzeneinschlüsse mit den magnetischen Materialeigenschaften korreliert und vom Keimabstand und der Korngrenzenorientierung abhängig ist. Mit Einsatz von bis zu 16 Keimkristallen gelang es, eindomänige Supraleiterhalbzeuge mit Höchstmaßen von (79 x 39 x 20) mm3 und Remanenzflussdichten von bis zu 1,3 T zu erzeugen.
Im Chargenprozess konnten abschließend Multi-Seeding-Funktionselemente mit anwendungskonformen geometrischen und magnetischen Materialeigenschaften zum Aufbau eines hochdynamischen Supraleitermotors reproduzierbar gefertigt werden. In Leistungstests wurde für die Dynamik des Motors mit 200.000 rpm/s ein Rekordwert erzielt – nun können die Motoren in der Anwendung erprobt werden.
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Συμβολή στην ανάλυση του ηλεκτρικού και του μαγνητικού πεδίου στο περιβάλλον εναερίων γραμμών ηλεκτρικής ενέργειαςΤζινευράκης, Αντώνιος 22 December 2009 (has links)
Η παρούσα διδακτορική διατριβή αποτελεί μια συμβολή στην ανάλυση του ηλεκτρικού πεδίου στο περιβάλλον εναέριων γραμμών απλού και διπλού κυκλώματος. Αναπτύσσονται αναλυτικές σχέσεις για τον ακριβή υπολογισμό της έντασης του ηλεκτρικού πεδίου καθώς και απλούστερες προσεγγιστικές σχέσεις. Η προτεινόμενη μέθοδος υπολογισμού προέκυψε από τον συνδυασμό της ανάλυσης των φορτίων των αγωγών σε συμμετρικές συνιστώσες, της περιγραφής της έντασης του ηλεκτρικού πεδίου με διπλούς μιγαδικούς αριθμούς και της χρήσης του αναπτύγματος πολυπόλων για την έκφραση της έντασης του ηλεκτρικού πεδίου. Με τους διπλούς μιγαδικούς αριθμούς επιτυγχάνεται η παράσταση με μιγαδικούς αριθμούς τόσο των χρονικά ημιτονοειδώς μεταβαλλόμενων μεγεθών (τάσεων και φορτίων) όσο και των γεωμετρικών αποστάσεων. Το ανάπτυγμα πολυπόλων είναι μια σειρά απείρων όρων, όπου ο κάθε επόμενος όρος είναι αντιστρόφως ανάλογος της αυξανόμενης δύναμης της απόστασης. Αναπτύσσονται επίσης ακριβείς αναλυτικές σχέσεις, καθώς και απλούστερες προσεγγιστικές σχέσεις, για τον υπολογισμό της μαγνητικής επαγωγής γραμμών διπλού κυκλώματος. Για την ανάπτυξη των σχέσεων αυτών συνδυάζεται η χρήση των διπλών μιγαδικών αριθμών με το ανάπτυγμα πολυπόλων για την έκφραση της μαγνητικής επαγωγής. / This thesis is a contribution to the analysis of the electric field in the vicinity of single-circuit and double-circuit overhead power lines. Analytical formulas are developed for the accurate calculation of the intensity of the electric field as well as simpler approximate formulas. The proposed calculation method has arisen from the combination of the analysis of the conductors’ charges in their symmetrical components, the description of the intensity of the electric field using double complex numbers and the use of multipole expansions to express the intensity of the electric field. The use of double complex numbers allows the simultaneous representation of sinusoidal varying quantities (voltages and charges) and geometrical distances with complex numbers. The multipole expansion is a series of infinite terms, where each term is inversely proportional to an increasing power of the distance. Accurate analytical formulas are also developed as well as simpler approximate formulas for the calculation of the magnetic flux density produced by double-circuit lines. For the development of those formulas the use of double complex numbers is combined with the multipole expansion to express the magnetic flux density.
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Evaluation des performances énergétiques d'une nouvelle génération d'éolienne off-shore / Energy performances assessment of a new generation offshore wind turbineKouevidjin, Modobozi 11 December 2015 (has links)
L’alternateur étudié dans cette thèse équipe une éolienne flottante à axe vertical. Il s’agit d’unemachine synchrone de 2MW, polyphasée, bobinée sur plots, à pas fractionnaire, à aimants et à prisedirecte. L’objectif majeur de la thèse est la caractérisation de cet alternateur afin d’en évaluer lesperformances. Une modélisation analytique de la perméance d'entrefer et de la force magnétomotriceont conduit à l'étude de l'induction d'entrefer dont le contenu harmonique s'est révélé êtreparticulièrement riche. La caractérisation a également porté sur la détermination des inductancespropres et mutuelles, avec un calage du modèle effectué en exploitant des mesures expérimentalesfaites à l’arrêt. La particularité de la machine étudiée nous a amené à considérer un enroulement fictiféquivalent dans le but de déterminer les inductances cycliques, nécessaires à l'établissement du schémamonophasé équivalent. De plus, le fonctionnement back to back de la machine a été étudié et simulé. Ilpermet de faire des tests de la machine elle-même mais aussi des éléments de la chaîne de conversion,sans l'utilisation d'une deuxième machine ou des pâles pour entraîner le rotor du prototype. Il offre enplus la possibilité de tester différents type de fonctionnements et d'évaluer la puissance que peutproduire la machine : différents scénario de fonctionnement ont été simulés et les paramètresnécessaires aux essais sur site ont été définis. Le fonctionnement back to back a fait l’objetd’investigation sur une machine synchrone classique. Les difficultés de fonctionnement ontnotamment pu être mises en évidence avec une modélisation analytique des phénomènesélectromagnétique qui s'y produisent et des essais expérimentaux. / The studied alternator equips a vertical axis offshore wind turbine. It is a 2MW fractional slotconcentrated winding permanent magnet synchronous polyphase machine, directly connected to bladeturbine. The principal purpose of this thesis consists in characterizing the alternator in order toevaluate its performances. The air gap permeance and the magnemotive force analytical modelingleads to study the air gap flux density and its harmonic content, which is particularly rich. Thecharacterization has also concerned the self and mutual inductance determination, which has requiredstalling the model by exploiting experimental measurements done at standstill. The particularity of thestudied machine leads us to consider an equivalent fictitious winding in order to determine the cyclicalinductances, necessary for the single-phase equivalent scheme establishment. Moreover, the machineback to back functioning has been studied and simulated. This functioning allows testing the machineitself and the other conversion chain subsystems, without using a second machine or blades to drivethe prototype rotor. It offers the possibility to test different types of operating points and to estimatethe power that can produce the studied machine: different operating points scenarios have beensimulated and parameters for tests have been defined. The back to back functioning of a classicalsynchronous machine has been also investigated, with an analytical modeling of the electromagneticphenomena and experimental tests.
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