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Characterization and reduction of line-to-line crosstalk on printed circuit boardsWelch, Joshua Adam January 1900 (has links)
Master of Science / Department of Electrical and Computer Engineering / William B. Kuhn / An important concern for high speed circuit designs is that of crosstalk and electromagnetic interference. In PCB board-level designs, crosstalk at microwave frequencies may result from imperfections in shielding of PCB interconnects or more generally transmission lines. Several studies have been done to characterize and improve the isolation between PCB transmission lines for both digital and RF circuits. For example, previous studies in the microwave region have examined the effect that line type, line length, and separation have on crosstalk and suggest that without full shielding, the upper limit of isolation is on the order of 60dB for traditional board-level lines [1].
In order to more fully characterize crosstalk and improve isolation above 60 dB, this thesis studies signal-to-ground-plane separation, considers advanced line types, and examines the effect of 3D shielding. Results are presented from 100MHz to 30GHz for the traditional transmission line structures of microstrip, CPW, differential pair and CPW differential pair. This study shows that with a halving of distance between signal and ground planes, isolation between transmission lines can be reduced by as much as 20dB, making this one of the best ways to improve performance. Advanced methods of shielding are then presented. Direct launch stripline and single-sided CPW improve upon existing crosstalk reduction techniques, while split shielding and ablation of dielectric PCB material are also proposed.
The data and additional crosstalk reduction techniques discussed in this thesis serve two purposes. One: with a more complete understanding of the effects that transmission line types and parameters have on crosstalk, engineers can quickly identify potential crosstalk issues and resolve them before manufacturing. Second, this thesis presents the engineer with four new additional techniques that may become available in advanced manufacturing environments. Such techniques can further reduce crosstalk and may allow for isolation values to approach 100 dB at the PC board level.
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Setup for residual magnetic field measurements in cryostatsvon Ehrenheim, Carl Filip January 2018 (has links)
This thesis covers considerations regarding commercially availble magnetic field sensors and the design work and assembly of a 3-axis magnetic field sensor of Hall technology that is tested for use in a cryostat at the FREIA laboratory, Uppsala university. The assembled sensor needs to withstand cryogenic temperatures and a high vacuum environment. A design for a mechanical structure that will be able to move a matrix of multiple sensors inside the cryostat is also covered. A short section discusses magnetoresistance magnetic field sensors for these purposes. The assembled sensor withstood a cryogenic test and a vacuum test separately, but it did start to show an odd behavior in a specific temperature range towards the last cycles of the cryogenic test. The printed ciruit board didn't show any damage on the board or the solder joints after operation in the vacuum environment.
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Entre a reforma e a revolução: o PCB e a revolução brasileira / Between the reformation and the revolution: the PCB and the brazilian revolutionOliveira, Eder Renato de [UNESP] 25 September 2017 (has links)
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Previous issue date: 2017-09-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objeto deste trabalho é a atuação do PCB – Partido Comunista Brasileiro no recorte temporal de 1942-1958, ou seja, da reorganização do partido em meio ao Estado Novo de Getúlio Vargas até o XX Congresso do Partido Comunista da União Soviética (PCUS). Diante do debate historiográfico que a atuação do PCB suscita, a pergunta que norteia nossa pesquisa é a seguinte: teria mesmo o partido buscado aliança tácita com a burguesia nacional? E isto o teria levado a ficar a reboque do trabalhismo? Diante disso, pareceu-nos muito mais a defesa tática da ordem para o fortalecimento da organização partidária do que propriamente uma “aliança”. Daí nossa hipótese de trabalho: a Teoria da Revolução Brasileira propugnada pelo PCB oscilou entre posições reformistas e revolucionárias e não obteve êxito, na prática, para levar adiante uma política autônoma, tanto nas fileiras internas como no seio da classe trabalhadora, ficando, indiretamente, a reboque do trabalhismo desenvolvimentista. Nossa conclusão é a de que, verifica-se, no entanto, que a política de alianças do PCB não era propositadamente de “reboquismo”. Os comunistas, ao longo do percurso histórico estudado, tiveram importantes êxitos táticos e lograram proeminência no seio da esquerda brasileira nos anos 1950. Defendemos também nesta pesquisa que a política de alianças dos comunistas teve como mote a via para o socialismo, em que pesem as enormes dificuldades de atuação dos seus membros, principalmente no período de clandestinidade. / The goal of this work is the PCB’s — Brazilian Communist Party — acting in the temporal hiatus of 1942 to 1958, i.e., from the Party’s reorganization during the New State of Getúlio Vargas to the XX Congress of the Communist Party of the Soviet Union (CPSU). Faced with the historiographical debate that emerges from the PCB’s acting, the question that guides our research is as follows: did the Party really intended to achieve a tacit alliance with the national bourgeoisie? And did this, if true, resulted in Party trailing behind Labourism? In light of this, it seemed to us much more a tactical defense of the order, to the strengthening of the Party’s organization, than strictly an “alliance”. From this emerges our hypothesis: that the Theory of the Brazilian Revolution put forward by PCB oscillated between reformist and revolutionary positions, failing to succeed, in practice, at realizing an autonomous policy, both in the internal ranks and in the core of the working class, staying, as result, indirectly trailed behind the developmental Laborism. We verify in our conclusion that, however, the alliances’ policy of the PCB wasn’t one intentionally “traillist”. The communists, over the studied historical period, had important tactical victories, achieving prominence inside the Brazilian Left in the 50’s. We also defend in this research that the communists’ policy of alliances had as motto the path to Socialism, a route side by side with the enormous difficulties in the acting of its members, especially when they were forced to go underground.
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As transformações do PCB e a democracia brasileiraMattos, Marcelo 16 December 2010 (has links)
Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Sociais, Departamento de Sociologia, 2010. / Submitted by Albânia Cézar de Melo (albania@bce.unb.br) on 2011-04-19T16:26:15Z
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2010_MarceloMattosSouza.pdf: 1117739 bytes, checksum: ee1d871ac7e1045f61a1b7fd902f00e5 (MD5) / Depois da Revolução russa de outubro de 1917, em 1922, foi criado no Brasil, o Partido Comunista Brasileiro (PCB), que, baseado na ditadura do proletariado, tornou-se um importante componente da história política brasileira até 1992, quando foi decretado o seu fim no X Congresso do partido. Durante seus 70 anos de existência, o PCB protagonizou uma luta pela democracia e pela própria sobrevivência, sofrendo diversas transformações que culminaram no seu X Congresso. Esta pesquisa pretende investigar qual a contribuição dessas
transformações para a construção da democracia brasileira que por diversas vezes foi ameaçada, principalmente na ditadura de Vargas e na ditadura militar de 1964 a 1985.
A luta pela democracia foi caracterizada por dois paradoxos: a autonomia versus a heteronomia em relação à URSS (adaptação do comunismo à cultura brasileira) e o paradoxo
da luta insurreta versus a luta democrática, pacífica, por um governo socialista.
Em razão desses paradoxos, o PCB foi enfraquecendo com o tempo, tendo basicamente dois causadores: 1º) as críticas que a teoria marxista-leninista vinha sofrendo no âmbito internacional e o próprio enfraquecimento do comunismo no mundo, que culminou com a queda do Muro de Berlim, em 1989, e com o fim da URSS, em 1991; 2º) os conflitos internos no partido decorrentes dos dois paradoxos citados, que fizeram diversos militantes importantes largarem a vida política ou o trocarem por outros partidos, além dos conflitos do Partidão com
outros partidos. Concluiu-se que os conflitos internos e externos enfraqueceram o PCB, por um lado, mas, por outro, serviram como substrato para fortalecer a democracia no partido – tão defendida pelo PPS, um dos partidos que surgiram como resultado do X Congresso do PCB – e do país. Além disso, percebeu-se que faltou ao PCB uma análise aprofundada da realidade brasileira antes de
tentar qualquer iniciativa em direção a uma revolução social que aumentasse a participação da sociedade civil na sociedade política. Para esse aprofundamento, sugere-se a utilização dos pensamentos de Gramsci, não necessariamente como método, mas pelo menos como referência de um estudo aprofundado de uma sociedade. ______________________________________________________________________________ ABSTRACT / After the Russian Revolution of October 1917, in 1922, was created in Brazil, the Partido Comunista Brasileiro (PCB), which, based on the dictatorship of the proletariat, has become an important component of Brazilian political history until 1992, when its X Congress decreed its
end. During its 70 years existence of the PCB staged a fight for democracy and survival facing changes that culminated in its Tenth Congress. This study intends to investigate the contribution of these transformations for the construction of Brazilian democracy that was threatened several times. Especially in the Vargas dictatorship and the military dictatorship
from 1964 to 1985. The struggle for democracy was characterized by two paradoxes: 1º) internationalism (influence of the URSS) versus nationalism (adaptation to Brazilian culture of communism); 2º) the paradox insurgent fighting the fight versus democratic, peaceful, for a socialist government. Because of these paradoxes PCB was fading with time, for basically two causes, the first criticism that the marxist-leninist theory was suffering at the international and own specific weakening of communism in the world which culminated in the fall of the Berlin Wall, in 1989, and the end of the USSR in 1991. The second were the conflicts within the party by the two paradoxes mentioned, who made several important people step out of politics life or go for other parties, besides the “Partidão” (the big party) conflicts with other parties. It was concluded that the internal and external conflicts that have weakened the PCB, on the other side served as a substrate for strengthening democracy in the party – as advocated by
PPS, one of the parties that arise how result the X Congress of the PCB – and country. In addition it was felt that it lacked the PCB depth analysis of the Brazilian reality before attempting any move toward a social revolution that would increase civil society participation
in political society. For further suggests that the use of Gramsci, not necessarily as a method, but as a reference for a study of a society. ______________________________________________________________________________ RÉSUMÉ / Après la Révolution russe d'Octobre 1917, en 1922, a été créé au Brésil, le Partido Comunista Brasileiro (PCB), qui, a fondé sur la dictature du prolétariat, est devenue une composante important de l'histoire politique brésilienne jusqua 1992, lorsque son dixième Congrès a décrétée sa fin. Au cours de ses 70 ans d'existence le PCB a organisé une lutte pour la démocratie et pour sa propre et metre une changements qui pandent sa dixième Congrès. Cette étude but à étudier la contribution de ces transformations pour la construction de la démocratie brésilienne qui a été menacé à plusieurs reprises. Principalment pendent la dictature de Vargas
et la dictature militaire de 1964 à 1985.
La lutte pour la démocratie a été caractérisé par deux paradoxes: 1º) internationalisme (influence de l'URSS) versus nationalisme (adaptation du communisme à la culture brésilienne); 2º) le paradoxe de la lutte insurgés versus lutte démocratique, pacifique, par un gouvernement socialiste. Principalement à cause de ces paradoxes le PCB a été affaibli pendent le temp, avec deux causes. La première la critique de la théorie marxiste-léniniste dans tout le monde et le affaiblissement du communisme dans le monde qui a été sa fin avec la chute du mur de Berlin, en 1989, et la fin de l'URSS en 1991. Les seconds motif sont les conflits au sein du parti par les
deux paradoxes mentionnés, qui a fait plusieurs militant important changer de parti au abandonner la vie politique et les conflit du “Partidão” (le grand parti) avec les autres parties. Il a été conclu que les conflits internes et externes qui dun coté ont affaibli le PCB et d’outre côté est a été un substrat pour le renforcement de la démocratie dans le parti – a défendu pour le
PPS, un des partis qui résultent du Dixiéme Congrès du PCB – et du pays. Il a a été conclu aussi que le PCB ne fait pas une analyse approfondie de la réalité brésilienne avant de tenter une révolution sociale qui augment la participation de la société civile dans la société politique.
Pour sa analyse de la société, nous suggèrons l'utilisation de Gramsci, pas nécessairement comme une méthode, mais comme une référence.
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Environmental, Toxicological, and Evolutionary Influences on Membrane Composition in FishGonzalez, Alyssa January 2016 (has links)
Many factors affect membrane composition in ectotherms, including allometry, temperature, toxins such as PCB-153, and osmotic stress. This thesis seeks to describe the relationship between membrane composition, size, and phylogeny in twelve species of cypriniform fish; to describe interactions between the homeoviscous responses to temperature and to PCB-153 in goldfish and rainbow trout; and to describe the membrane response to hypoosmotic stress in goldfish. Commonalities in these patterns provide insight into shared mechanisms of phospholipid modulation. In particular, such similarities indicate whether the membrane pacemaker theory of metabolism, which connects allometric relationships between body size, membrane phospholipids, and metabolic rate, can serve as a general framework for understanding membrane composition. Chapter 2 investigates how cypriniform membrane unsaturation decreases with mass through different fatty acid substitutions than in endotherms, but these fatty acids are in turn shown to be due to the species’ relatedness to one another rather than to purely physiological causes. In Chapter 3, PCB-153 is shown to increase cholesterol in liver and brain, while high temperature primarily reduces phospholipid unsaturation. In Chapter 4, these patterns are further explored in trout. As in goldfish, cholesterol modulation is the primary response to PCB-153, whereas temperature primarily reduces phospholipid unsaturation. Trout show more pervasive fatty acid changes than goldfish in all tissues except the liver, which does not respond to PCB exposure, suggesting that PCB-153 pushes trout’s homeoviscous response to a limit that similarly-exposed goldfish do not face. Chapter 5 shows that goldfish intestines decrease membrane saturation; kidneys decrease membrane cholesterol; gills decrease neither; and muscles decrease both in response to long-term exposure to hypoosmotic conditions. The intestine and kidney are both involved in recovering ions from body fluids, but gills suppress ion loss and muscle concentrates ions from the bloodstream. Temperature, osmotic stress, PCB-153, and increasing body size are all addressed via a similar set of membrane responses in fish, which fits with the membrane pacemaker theory’s predictions regarding membrane composition, metabolic rate, and size.
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Výukový model pro mechatroniku: vývoj modelu a rychlé komunikace pomocí USB / Educating model for mechatronics: model development and fast USB communicationFormánek, Martin January 2020 (has links)
Táto diplomová práca sa zaoberá návrhom a realizáciou výukového modelu pre študentov mechatroniky na vysokej škole. Úvod práce sa zaoberá krátkym uvedením do problematiky používania univerzálnej sériovej zbernice a jej implementáciou pre komunikáciu s mikrokontrolérom. Druhá časť je venovaná hardwaru zariadenia, medzi čo patrí voľba vhodného motoru, návrh vhodných elektronických komponentov, návrh dosiek plošných spojov a taktiež mechanickej konštrukcie celého zariadenia. Nasleduje softwarová časť, popisujúca praktickú realizáciu komunikácie, program v mikrokontroléry, a Toolbox, ktorý umožňuje užívateľovi jednoduchú interakciu s hardwarom a to jak z Matlabu. tak zo Simulinku. Kombinácia navrhnutých hardwarových a softwarových prvkov umožňuje jednoduchú cestu k zlepšeniu vedomostí študentov v oblastiach programovania, riadenia a modelovaní sústav. Pre tieto účely je práca rozšírená o pracovný list, ktorý dopĺňa navrhnuté zariadenie o sadu experimentálnych úloh, zameraných na vybrané mechatronické problémy.
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Komunikační rozhraní standardu Aerospace Industry Bus ARINC429 / Aerospace Industry Bus ARINC429 Low Cost Communication InterfaceMichna, Jakub January 2015 (has links)
The aim of this work was to create a communication interface of standard ARINC Aerospace Industry Bus 429. The work has slightly outlined existing solutions, from which it can draw inspiration. Further analysis was performed, analysis of ARINC 429 bus, analysis of Raspberry Pi platform on which the solution will be built, and analysis of selected bus controller HI-3593. After that concept was created, based on concept was created the scheme contains circuitry HI-3593. On the basis of the scheme was created DPS. Next was created software for DPS. In the end of this work was tested abilities to receive and send messages on the bus ARINC 429.
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Automatic Probing System for PCB : Analysis of an automatic probing system for design verification of printed circuit boardsAalto, Alve, Jafari, Ali January 2015 (has links)
The purpose of this thesis is to conduct an analysis of whether the printed circuit boards from Ericsson can be tested using an automatic probing system or what changes in the design are required, to be a viable solution. The main instrument used for analyzing the printed circuit board was an oscilloscope. The oscilloscope was used to get the raw data for plotting the difference between the theoretical and actual signals. Connected to the oscilloscope was a 600A-AT probe from LeCroy. The programs used for interpreting the raw data extracted from the oscilloscope included Python, Matlab and Excel. For simulations on how an extra via in the signal path would affect the end results we used HFSS and ADS. The results were extracted into different Excel sheets to get an easier overview of the results. The results showed that the design of a board must almost become completely rebuilt for the changes, and it is therefore better to implement in a new circuit board rather than in an already existing one. Some of the components have to either be smaller or placed on one side of the board, where they cannot be in the way of the probe. The size of the board will become larger since the rules of via placements will be limited compared to before. The most time demanding part was the simulations of the extra via in the signal path, and the results showed that if a single-ended signal is below two gigahertz the placing of the via does not make a big difference, but if the signal has a higher frequency the placement is mostly dependent on the type of the signal. The optimal placement is generally around four millimeters away from the receiving end. / Målet med detta examensarbete är att göra en analys av huruvida Ericssons kretskort kan testas med hjälp av ett automatiskt probe system eller om det kräver stora förändringar i designdelen av kretskorten och om, vad för förändringar det i sådant fall kan vara. Till hjälp att analysera kretskorten har vi haft oscilloskop för att få ut rådata om skillnaderna mellan de teoretiska och verkliga signalerna. För att kunna tyda oscilloskopets samplade signaler har olika programmeringsspråk som Python, Matlab samt Excel använts. En extra via i signalens väg har även simulerats i HFSS och ADS med olika sorts probar för att se hur signalens beteende påverkas. Resultaten extraherades sedan in i olika Excel ark för att få en lätt överskådlig bild av resultaten. Resultatet vi fick visade att utformningen av ett kretskort med ändringarna skulle vara lättare att göra med en ny design istället för en redan existerande då större delar av kortet skulle behöva göras om. Vissa stora komponenter behöver antingen göras om, hitta mindre men likvärdiga eller sättas på ena sidan av kortet där de inte är i vägen för proben. Kretskorten som kommer använda flygande probesystem kommer antagligen bli lite större då viornas placering är mer begränsade än tidigare. Det mest tidskrävande arbetet var att simulera olika placeringar av en extra via i signalens väg. Detta visade att på en single ended signal under två gigahertz så gör det ingen större skillnad vart i signalens väg som den extra vian placeras. Då en högre frekvens används så är själva signalens karaktär det viktigaste än placeringen av en via, men om man inte vet den exakta karaktären så är fyra millimeter bort från mottagarens sida att rekommendera då närmare placering av viorna gör att signalerna börjar störa varandra.
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Utveckling av lastsimulator för test och felsökning av befintlig utrustningStenlund, Joel January 2021 (has links)
För att testa en befintlig anodiseringsutrustning behövde Prevas Development AB en elektronisk last som kunde simulera en resistans, med en loggfil som utgångspunkt. Detta åstadkoms genom en återkopplad regulator som styr en MOSFET. Dessutom används optisk isolering för att isolera styrelektronik från den höga spänningen från anodiseringsutrustningen. I rapporten redovisas de viktigaste valen och resultatet av test och utvärdering, samt områden för framtida förrbä ttring.
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Univerzálna platforma IoT senzorov novej generácieLučanský, Adam January 2020 (has links)
The thesis examines hardware IoT platforms, surveys existing platforms and designs modular IoT platform consisting of printed-circuit boards interconnected with M2.COM standard. LoRaWAN modem is used for wireless data transfer. External sensors are connected to the device using connector mikroBUS and QWIIC. Whole system is tested by counting pulses from selected water flow-meter.
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