Submitted by Nadir Basilio (nadirsb@uninove.br) on 2018-06-21T18:42:55Z No. of bitstreams: 1 Heliodora Leao Casalechi.pdf: 2679810 bytes, checksum: f981677bdc05834caca5e26029e42566 (MD5) / Made available in DSpace on 2018-06-21T18:42:55Z (GMT). No. of bitstreams: 1 Heliodora Leao Casalechi.pdf: 2679810 bytes, checksum: f981677bdc05834caca5e26029e42566 (MD5) Previous issue date: 2015-06-24 / Tendinitis is a common disorder of the musculoskeletal system with multiple pathological manifestations. Although most tendons have the ability to spontaneously repair after injury, scar tissue is formed that can prevent the tendon to perform normal functions. Studies have been conducted using phototherapy in different health areas, using low-intensity lasers and LEDs. However, there are few studies with LEDs therapy. The aim of this study was to investigate the effect of phototherapy with Laser (830nm) and LED (945nm) in the repair process of the calcaneus tendonitis in rats. The inflammation was induced by controlled contusion in the medial region of the Achilles tendon of the animals. Was used 112 young male Wistar rats (240 ± 20g), divided into 14 groups with two different experimental periods. Groups CONT (control group), TEND (tendinitis group) during periods 7 and 14 days, LEDT (LED therapy, from th to 7th day and from 1th to 14th day), and LEDT delay (LED therapy from 7th to 14th day). The therapy was initiated 12h after the tendinitis induction, with a 48h interval between irradiations (dose 6J/point). The control animals received simulation of treatment; the same experimental design was used for Laser treatment. All groups were euthanized on the 7th or 14th day after the induction. The tendons were dissected, extracted, and sent for analysis. Were performed biomechanical and histological analysis to evaluate neutrophils and collagen, were also quantitated the inflammatory mediators by real-time polymerase chain reaction (RT-PCR) and the IL-6 and TNF- α levels by ELISA. The results showed that treatments with low-intensity lasers in the parameters used and the times studied reduces migration of inflammatory cells and improves the quality of repair, but the LED even decreasing the inflammation was not effective of biomechanical properties of tendon tissue. / A tendinite é uma desordem comum do sistema musculoesquelético. Embora os tendões tenham habilidade de reparação espontânea após ferimento, o tecido da cicatrização que é formado pode impedir o tendão de executar as funções normais. Estudos vêm sendo realizados utilizando a fototerapia em diferentes áreas da saúde, empregando tanto laseres quanto LEDs de baixa intensidade. Contudo, existe um número reduzido de estudos com a utilização da terapia com LEDs. O objetivo deste estudo foi investigar os efeitos anti-inflamatórios e as propriedades mecânicas do tecido após a ação da fototerapia utilizando LASER (830nm) e LEDs (945nm), na região do infravermelho, na tendinite induzida por trauma mecânico em tendão de Aquiles de ratos. Foram utilizados 112 ratos machos albinos da linhagem Wistar (240 ± 20g), distribuídos em 14 grupos e dois períodos experimentais diferentes. Grupos CONT (grupo controle), os grupos TEND (grupos tendinite) nos períodos de 7 e 14 dias, o LEDT (grupos terapia LED), do 1º ao 7º dia e do 1º ao 14º dia) e o grupo LEDT delay (terapia LED do 7º ao 14º dia). A terapia teve início 12 horas após a indução da tendinite, utilizando uma dose de 6J no ponto de aplicação, com intervalos de 48 em 48 horas. A fototerapia foi aplicada transcutaneamente em um único ponto sobre a região lesionada. Os animais dos grupos controle foram submetidos à simulação da aplicação com o aparelho desligado, o mesmo desenho experimental foi utilizado feito para o tratamento Laser. As eutanásias ocorreram ao 7º e 14º dia do experimento. Foi realizada análise biomecânica, histopatológica para avaliação de neutrófilos e colágeno, também foram quantificados os mediadores inflamatórios por meio da RT-PCR e os níveis de IL-6 e TNF- α foram avaliados pelo teste imunoenzimático (ELISA). Por meio dos resultados encontrados, é possível inferir que os tratamentos com Laser de baixa intensidade, nos parâmetros utilizados e nos tempos estudados melhora a qualidade do reparo do tecido tendíneo, a biomecânica e reduz a migração de células inflamatórias, já o LED de baixa intensidade apesar de diminuir a inflamação não foi eficiente na manutenção da biomecânica do tendão.

Abstract That greenhouse gas (GHG) emission causes ¡§Global Warming¡¨ is a human common problem today in the earth. The GHG emission will gradually promote our weather temperature and change which we must pay for a lot. For example, the warming temperature will dissolve icebergs, that it will elevate the sea level. Also, our land area will decrease. If climate zones were shifted, it would be possible to initiate some animals migrate. In the worse case, our living space will be squeezed and some special diseases will be spread out¡Ketc. In view of environmental protection awareness in every country, we must face the problem and crisis which comes from ¡§Global Warming¡¨ and ¡§Heating Pollution¡¨. In June of 1992, there was a meeting in Rio of Brazil. All representatives who comes from 153 different countries sign an agreement ¡V the United Nations Framework Convention on Climate Change (UNFCCC). They try to stabilize greenhouse gas concentrations at a level that would prevent dangerous interference with the climate and environmental system. To achieve this goal, the Kyoto Protocol was adopted on COP3 in December 1997 to place legally binding limits on GHG emissions. This Protocol norms 38 countries and European Union. In June 2007, the Group of Eight (G8) have reached a consensus and expect in year 2050, CO2 emissions can be reduced to the half of current emissions. We can see that, every country is vigorous to look for alternative energy that eliminates the environment destroyed and saves the earth resources. For example, Solar Energy, Water Energy, Wind Energy, Biomass Energy, Ocean Energy and Geothermal Energy¡Ketc. Those are gradually developed and applied in our daily life. My research is focus on the LED applications based on the substitution of traditional lighting. Actually, LED has all advantage of the energy saving, eco-lighting and economy of scale. How to use this alternative lighting is of great urgency and the major topic in light source manufacturers. For example, if America can replace their 55% white heat bulbs and 55% fluorescent lamps by LED before 2010, they can save 35 billion US dollars every year. For Japan, if they replace 100% white heat bulbs, they can save one to two of Nuclear Power Plants. Also, they can save above 100 million of gasoline every year. As to Taiwan official estimation, we can save 11 billion electricity degrees every year when we replace 25% white heat bulbs and 100% fluorescent lamps. That electric power is approximate to save one Nuclear Power Plant and 50 million of gasoline every year. According to the data above, the population of LED will give us a lot of eco-benefits. My report leans on researching and treating LED. Then, I take one step ahead to demonstrate how important it is to apply LED on our human light source and the effects of earth environment. Keywords: Greenhouse Gas (GHG) Global Warming United Nations Framework Convention on Climate Change (UNFCCC) Kyoto Protocol Biomass Energy LED - Light Emitting Diode (display)

Integration of optical wireless communications (OWC) within switched-mode power supplies (SMPS) / Although visible light communication(VLC) systems can provide high density links for use with IoT devices, an energy efficient, high rate method of designing a VLC transmitter is still unclear. Present designs for transmitters such as the bias-T, designs with switch manipulation, and interleaved converters are not commercially viable due to costly and complex designs that sacrifice energy efficiency for data rate. A design allowing for efficient, high rate communications, while maintaining a low cost would allow for widespread adoption of this technology. In this thesis, a novel approach of integrating power converters and VLC systems is explored by replacing commutating diodes with LEDs. By leveraging switched-mode power supply(SMPS) structures, the power dissipated within the converter may be harnessed and used for communications. The result is a simple and energy efficient solution capable of high rate links. Simulation and experimental results demonstrate buck and boost SMPS topologies that simultaneously increase energy efficiency and provide communications at SMPS switching rate without increasing component count. / Thesis / Master of Applied Science (MASc)

Les procédés de photopolymérisation connaissent un développement important avec des applications considérables dans le milieu industriel en raison de ses avantages économiques et écologiques. Les réactions de photopolymérisation sont très représentées, elles reposent sur l’utilisation d’un composé ou d'un système photosensible sous irradiation, générant des espèces réactives capables d’amorcer la polymérisation et de réagir avec le monomère. Le principal objectif de ce travail de thèse consiste à développer des molécules efficaces comme photoamorceurs (PA) pour la photopolymérisation radicalaire (FRP) d’une part et la photopolymérisation cationique (CP) ou la photopolymérisation cationique sensibilisée par les radicaux (FRPCP) d’autre part. Nous nous sommes intéressés à des systèmes amorceurs hautes performances absorbant fortement dans le domaine du visible et permettant l’utilisation de lampes non nocives et à faible consommation d'énergie : les diodes électroluminescentes (LED). Ainsi, un procédé original portant sur la combinaison de la photopolymérisation radicalaire et la photopolymérisation cationique en une seule étape a été examiné. Cette approche a fait appel à la synthèse de réseaux interpénétrés de polymères (RIP) comportant les propriétés spécifiques de chaque polymère. Les efforts ont été consacrés au développement de nouveaux composés avec de nouvelles structures chimiques et d’excellentes propriétés d’absorption de lumière avec de coefficients d’extinctions molaires très élevés.Des systèmes construits sur l’utilisation de différentes structures comme photoamorceurs ont pu être mis au point dans le cadre de cette thèse. La possibilité d’utiliser des colorants présentant un caractère push-pull, ou des colorants étant caractérisés par une structure polyène ou une structure polyaromatique a pu être considérée. Egalement, des structures à base de xanthène sensibles dans le domaine proche visible ont pu être proposées. De plus, ce travail a permis d’étudier de nouveaux systèmes photoamorceurs à base de structures minérales telles que les polyoxométallates ou les pérovskites. Ainsi, la possibilité de proposer de nouveaux sels d’iodonium à base de coumarine a pu être démontrée. Des meilleures performances ont été atteintes en utilisant des systèmes photoamorceurs à deux composants (PA/Ph2I+) ou à trois composants (PA/Ph2I+/additif) dans des conditions d’irradiation douce. Afin d’étudier et caractériser ces photoamorceurs, la cinétique de la réaction de photopolymérisation a été suivie par spectroscopie infrarouge à transformée de Fourier (RT-FTIR). Les radicaux générés ont été détectés par résonance paramagnétique électronique (RPE). La photolyse laser éclair (LFP) a été utilisée comme technique complémentaire pour étudier l’efficacité et la réactivité de radicaux générés. / The photopolymerization reaction is used in an increasing number of industrial applications because of the remarkable performance of the process. The photopolymerization reactions require the presence of photosensitive compounds. These latter can absorb light and participate in the photoinitiation through the generation of reactive species. The main objective of this PHD was to develop efficient molecules as photoinitiators (PI) for the free radical photopolymerization (FRP), the cationic photopolymerization (CP) and the free radical promoted cationic photopolymerization (FRPCP). We were interested in new high performance photoinitiating systems (PISs) exhibiting excellent light absorption properties (especially in the visible wavelength range). The photopolymerization must be carried out under soft irradiation conditions (non harmful lamps, low energy consumption and low intensity sources: light-emitting diodes LED). Thus, a novel method involving concomitant radical/cationic photopolymerization in one step was examined. This approach involves the synthesis of interpenetrating polymer networks (IPNs) comprising the specific properties of each polymer. The efforts have been devoted to the development of new compounds with new chemical structures and excellent light absorption properties with high molar extinctions coefficients.Many PISs based on different photoinitiators structures have been developed in this work. The possibility to use dyes having a push-pull character, or dyes being characterized by a polyene or polyaromatic structures were considered. Also, originals xanthenes derivatives sensitive in the visible region have been proposed. In particular, this work has enabled the study of new PISs based on inorganic structures such as polyoxometalates and perovskites. Thus, the possibility to propose new iodonium salts based coumarin could be demonstrated. The best performance was achieved using two-components (PI/Ph2I+) or three-components (PI /Ph2I+/additive) photoinitiating systems under soft irradiation conditions. The kinetics of photopolymerization were evaluated using real time FTIR spectroscopy. The generated radicals were observed using the electron spin resonance (ESR) technique. The laser flash photolysis (LFP) was used as a complementary technique to study the efficiency and the reactivity of radicals generated.

Examensarbetet är en undersökning avseende implementering av Human Centric Lighting (HCL)- system i hemmamiljö. En litteraturstudie har genomförts om HCL, dess effekter på människan och LED-belysningens påverkan både på människan och miljön. För att få en bra praktisk grund gjordes även ett undersökande besök på Lindeborgsskolan i Malmö som i ett pilotprojekt har installerat HCL-system i ett klassrum. HCL handlar bland annat om att anpassa ljuset till människans varierande behov genom att variera intensitet (Lux) och färgtemperatur (Kelvin). Belysning har stor betydelse för människans välmående där en belysning med onaturlig spektralfördelning och flimmer kan leda till stress, sömnproblem samt att ögonen kan försämras. Ett bra varierande ljus kan däremot öka människans välmående, produktivitet och även ge en positivare inställning. En del forskning visar även på att HCL kan minska risken för årstidsbunden depression. Ett blått, mer intensivt ljus har en uppiggande effekt medan ett rött nerdämpat ljus verkar lugnande. Genom att utsätta kroppen för mycket blått ljus på förmiddagen men inte på eftermiddagen/kvällen gynnas kroppens cirkadiska cykel. Även rött ljus har visat sig ha en uppiggande effekt men påverkar inte den cirkadiska cykeln och kan med fördel användas även på kvällstid om en högre ljusintensitet behövs. Tre separata reglerbara belysningssystem har undersökts: Clas Ohlson WiFi Smart Bulb, IKEA trådfri belysning och Philips Hue White Ambiance. Kravet som ställdes för att belysningen skulle tas med i testet var att den skulle finnas tillgänglig i en relativt vanlig butik. Belysningen har testats både med avseende på ljusegenskaper samt energianvändning. En del av mätningarna utfördes med ett Ulbrichtklot på Clas Ohlsons ljuslaboratorium där färgspektrum, lumenvärde samt mycket annan information om ljuskällan kunde tas fram, samt med en handhållen spektrometer för att se flimmeravgivningen ifrån lampan vid olika inställningar. Energianvändningen undersöktes beträffande förändringar vid variation av färgtemperatur, intensitet och även i de fall som separat reglerutrustning krävdes. De tre belysningssystemen visade sig ha olika fördelar och nackdelar där en till slut valdes ut för att installeras i ett sovrum i utbildningsprojektet Dalarnas Villa. Baserat på ett tidigare gjort ljusschema, i en masteruppsats gjord av en ljusdesigner vid KTH, togs ett nytt ljusschema fram för sovrummet som förändrar ljusets intensitet och färgtemperatur för att främja den cirkadiska cykeln. Då författarna ser att detta är ett viktigt ämne så har varje möjlighet till att visa upp det installerade systemet tagits. Vid samtal med bland annat energirådgivare från Dalarna så har ett stort intresse visats. ” Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity (WHO 1946). Health should be at the centre of all societal planning because social inequalities in health are costly to the society and counteract sustainable development (Malmö stad 2013). It is one of the main conditions for individual development opportunities through education, work, social relationships and participation in the society (UN 1949). Health is a key to the other human rights and also constitutes a separate right (WHO 2008).” Sustainability issues for SSL (R. Karlsson et al. 2016) / This thesis is a study concerning the implementation of Human Centric Lighting (HCL)-systems in the home environment. A literature study has been conducted on light, its effects on humans and the influence of LED lighting on both humans and the environment. To obtain a good practical foundation, an investigative study visit was also made to Lindeborgsskolan in Malmö, which as a pilot project has installed HCL systems in a classroom. HCL is, among other things, about adapting the light to man's varying needs by varying intensity (Lux) and color temperature (Kelvin). Lighting is of great importance to human well-being where lighting with unnatural spectral distribution and flicker can lead to stress, sleep problems and that the eyes can deteriorate. A good variety of light can, on the other hand, increase human well-being, productivity and give a positive attitude. Some research also shows that HCL can reduce the risk of seasonal depression. A blue, more intense light has a wakeup effect, while a red low intensity light feels soothing. By exposing the body to much blue light in the morning but not in the afternoon / evening, the body's circadian cycle benefits. Even red light has been shown to have a stimulating effect but does not affect the circadian cycle and can be used even in the evening if a higher light intensity is needed. Three separate controllable lighting systems have been investigated: “Clas Ohlson Wi-Fi Smart Bulb”, “IKEA trådfri” and “Philips Hue White Ambiance”. The lighting has been tested both in terms of light quality and energy use. The light quality was examined partly with an “Ulbrichtklot” at Clas Ohlson's light laboratory where color spectrum as well as various other information could be obtained, and with a hand-held spectrometer to see the flicker output from the lamp at different settings. The energy consumption was investigated regarding variation of color temperature, intensity and even in cases where separate control equipment was required. The three lighting systems were shown to have different advantages where eventually the Philips Hue Ambience White was selected to be installed in a bedroom in the project villa Dalarnas Villa. Based on a previous master thesis, a light schedule was developed that changes the intensity and color temperature of light to promote the circadian cycle. As the authors see this as an important topic, every opportunity to show the installed system has been taken. A great deal of interest has been shown during discussions including Dalarna´s energy advisers. ” Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity (WHO 1946). Health should be at the centre of all societal planning because social inequalities in health are costly to the society and counteract sustainable development (Malmö stad 2013). It is one of the main conditions for individual development opportunities through education, work, social relationships and participation in the society (UN 1949). Health is a key to the other human rights and also constitutes a separate right (WHO 2008).” Sustainability issues for SSL (R. Karlsson et al. 2016)

Der externe Wirkungsquerschnitt von auf AlGaAs/InGaAlP basierenden Leuchtdioden (LEDs) ist auf Grund von Totalreflexion infolge des hohen Brechungsindex des Halbleitermaterials (n=3...4) beschränkt. Auf die Oberfläche der LED aufgebrachte metallische Nanoteilchen (MNT) können jedoch als Dipolstreuer genutzt werden, um so die Emission der LED zu vergrößern. In dieser Arbeit wurden zunächst einzelne Goldnanoteilchen verschiedener Größe auf einer solchen Leuchtdiode in zwei verschiedenen Der externe Wirkungsquerschnitt von auf AlGaAs/InGaAlP basierenden Leuchtdioden (LEDs) ist auf Grund von Totalreflexion infolge des hohen Brechungsindex des Halbleitermaterials (n=3...4) beschränkt. Auf die Oberfläche der LED aufgebrachte metallische Nanoteilchen (MNT) können jedoch als Dipolstreuer genutzt werden, um so die Emission der LED zu vergrößern. In dieser Arbeit wurden zunächst einzelne Goldnanoteilchen verschiedener Größe auf einer solchen Leuchtdiode in zwei verschiedenen Umgebungsmedien untersucht. Dabei zeigt sich eine deutliche Verstärkung der Emission, falls die Dipolresonanz des MNT bei kürzeren Wellenlängen im Vergleich zur LED-Emission liegt. Für den Fall, dass die Dipolresonanz mit der Emission überlappt oder bei größeren Wellenlängen liegt, kommt es zu einer Abschwächung. Numerische Berechnungen zeigen, dass dabei die Stärke der Quadrupolmode, welche zusätzliche Absorption hervorruft, sowie eine Rotverschiebung der Dipolresonanz bei Anregung oberhalb des kritischen Winkels der Totalreflexion eine entscheidende Rolle spielen. Mit Hilfe einer speziellen Maskentechnik, der Fischer-Pattern-Nanolithographie, können Arrays von MNT hergestellt und anschließend die MNT in Form und Größe manipuliert werden. Die zunächst dreieckige Form der Partikel führt zu einer Abschwächung der Emission, welche sich aber durch Umwandlung der MNT in Kugeln zu einer Emissionsverstärkung wendet. Dabei kann Licht, welches sonst im Substrat gefangen wäre, durch plasmonische Streuung ausgekoppelt werden. Eine Untersuchung ähnlicher Strukturen auf einem hochbrechenden, transparenten Substrat (GaP) zeigt, dass die Lage der plasmonischen Resonanzen stärker vom Abstand der Partikel abhängt, als gewöhnlich zu erwarten wäre.:1 Eigenschaften metallischer Nanoteilchen 2 Untersuchung der Lichtauskopplungsverstärkung einzelner Metalnanoteilchen auf der LED 3 Regelmäßig angeordnete metallische Nanoteilchen - Herstellung und Verstärkungseigenschaften 4 Manipulation der Größe metallischer Nanopartikel 5 Eigenschaften eines Arrays metallischer Nanopartikel auf einem hochbrechenden Substrat 6 Abschlussdiskussion / The external quantum efficiency of light-emitting diodes (LEDs) based on AlGaAs/InGaAlP is limited by total internal reflection because of the high refractive index (typically between 3 and 4) of the semiconductor. Metal nanoparticles (MNP) deposited on the surface of the LED can be used as dipole scatterers in order to enhance the emission of the LED. In this thesis, first, single gold nanoparticles of various sizes deposited on such an LED were investigated. A clear enhancement is detected as long as the dipole plasmon resonance of the particle is at a shorter wavelength than the LED emission. If the plasmon resonance coincides with the LED emission or is at a larger wavelength, the enhancement turns into suppression. Numerical simulations indicate that this latter effect is mainly caused by the particle quadrupole resonance producing extra absorption. Arrays of MNPs can be produced by a special mask technique called \"Fischer pattern nanolithography\" and manipulated in shape and size by additional steps. Originally, the MNPs produced by this technique are triangular in shape and turn out to suppress the LED emission. After transformation of the particles to spheres, a clear enhancement was detected. Light that would otherwise remain trapped inside the substrate is coupled out by resonant plasmonic scattering. Investigations on analogous structures on a transparent high-index material (GaP) indicate a stronger coupling between the particles than expected on the basis of literature data.:1 Eigenschaften metallischer Nanoteilchen 2 Untersuchung der Lichtauskopplungsverstärkung einzelner Metalnanoteilchen auf der LED 3 Regelmäßig angeordnete metallische Nanoteilchen - Herstellung und Verstärkungseigenschaften 4 Manipulation der Größe metallischer Nanopartikel 5 Eigenschaften eines Arrays metallischer Nanopartikel auf einem hochbrechenden Substrat 6 Abschlussdiskussion

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-06-29T20:52:05Z No. of bitstreams: 1 JOSÉ ALBERTO CAMPOS DA SILVA JÚNIOR – DISSERTAÇÃO (UAEMa) 2015.pdf: 3855504 bytes, checksum: 02bbfa20b694c9416d048edd8410bfd4 (MD5) / Made available in DSpace on 2018-06-29T20:52:05Z (GMT). No. of bitstreams: 1 JOSÉ ALBERTO CAMPOS DA SILVA JÚNIOR – DISSERTAÇÃO (UAEMa) 2015.pdf: 3855504 bytes, checksum: 02bbfa20b694c9416d048edd8410bfd4 (MD5) Previous issue date: 2015-03-17 / O monitoramento neurofisiológico intraoperatório (MNIO) é uma metodologia que agrega diferentes testes neurofisiológicos para uso simultâneo ou alternado num mesmo paciente durante o procedimento cirúrgico, podendo avaliar a neurofisiologia clínica em três campos: eletroencefalografia (EEG), eletromiografia (EMG) e potenciais evocados (PE). O potencial evocado visual (PEV) permite avaliar a função e integridade das estruturas corticais e subcorticais da via visual. Este exame é realizado cotidianamente nos laboratórios de neurofisiologia, auxiliando o esclarecimento de diferentes tipos de acometimentos da visão, seja por doença ou traumatismos. Este trabalho tem como objetivo desenvolver um protótipo para o monitoramento do PEV para avaliação da integridade das vias visuais durante cirurgias neurofisiológicas. Foram realizadas várias etapas para o desenvolvimento do protótipo do dispositivo ocular: simulação computacional; estudo das características do olho humano; prototipagem rápida; caracterização do Biopolímero ácido polilático (PLA) utilizado na prototipagem; desenvolvimento de um protótipo de dispositivo ocular com sistema de iluminação integrado por LEDs a realização dos testes de PEV com o protótipo desenvolvido. O PLA utilizado na prototipagem para o desenvolvimento de partes do dispositivo ocular foi caracterizado por Difração de Raios X (DRX), Espectroscopia na Região do Infravermelho por Transformada de Fourier (FTIR), Calorimetria Exploratória Diferencial (DSC), Microscopia Ótica (MO), Microscopia Eletrônica de Varredura (MEV) e Espectroscopia de Energia Dispersiva (EDS), esses resultados mostraram que a prototipagem rápida não alterou as propriedades físico-químicas e morfológicas do PLA. A simulação computacional forneceu parâmetros adequados ao desenvolvimento do dispositivo ocular que possibilitou uma maior eficiência na montagem do circuito eletrônico. Os resultados dos testes de PEV foram realizados em diferentes pacientes, com os olhos fechados e os mostraram-se promissores para uso em pacientes anestesiados. / Intraoperative neurophysiological monitoring (MNIO) is a methodology that combines different neurophysiological tests for simultaneous or alternating in the same patient during the surgical procedure can evaluate the clinical neurophysiology in three fields: electroencephalography (EEG), electromyography (EMG) and evoked potential (EP). The visual evoked potential (VEP) evaluates the function and integrity of cortical and subcortical structures of the visual pathway. This test is performed daily in neurophysiology laboratories, helping the clarifying of different types of bouts vision, whether by disease or trauma. This study aimed to develop a prototype for monitoring the VEP to assess the integrity of the visual pathways during neurophysiological surgeries. Several steps were performed for the prototype ocular device: computer simulation; study of the characteristics of the human eye; rapid prototyping; Biopolymer characterization of polylactic acid (PLA) used in prototyping; development of an ocular device prototype with integrated lighting system and VEP achievement tests with the prototype. The PLA used in the prototype for the development of parts of the device eye was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), optical microscopy (OM), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), these results showed that the rapid prototyping did not change the physical-chemical and morphological PLA. The computer simulation provides appropriate parameters for the development of ocular device that allowed greater efficiency in the assembly of electronic circuit. The results of ENP tests were performed in different patients, with closed eyes and have shown promise for use in anesthetized patients.

In der vorliegenden Arbeit werden Möglichkeiten zur Maximierung der Effizienz von stromregelnden DC/DC-Wandlern für den Betrieb von Hochleistungs-LEDs in PKW-und Motorrad-Beleuchtungseinrichtungen untersucht, mit dem Ziel, das Gewicht und den Energieverbrauch der Steuergeräte zu reduzieren und so zu dem stetigen Bestreben der Minimierung der Gesamtfahrzeugemissionen beizutragen. Dafür werden verschiedene, teils sequenziell aufbauende Maßnahmen in Topologie, Bauelementen, Dimensionierung und Betriebsart betrachtet. Eine grundlegende Herausforderung für die Auslegung der Schaltung stellt dabei deren universelle Verwendbarkeit als Gleichteil in einem großen Bereich an Ausgangsstrom und -spannung in den individuellen Scheinwerfersystemen der verschiedenen Fahrzeugderivate dar. Die Grundlage für die Verringerung der Verlustleistung bildet die Vereinfachung der Schaltreglertopologie hinsichtlich des Bauteilaufwands. Dies wird durch die Versorgung der Schaltung aus dem 48 V-Energiebordnetz und die Verwendung der Topologie des Tiefsetzstellers erreicht. Elementarer Anteil dieser Arbeit ist die Untersuchung der Wirksamkeit des Einsatzes neuartiger Galliumnitrid-Leistungsschalter (GaN-HEMTs) anstelle der konventionellen Silizium-MOSFETs, was zunächst an Hand von Berechnungen und schaltungstechnischen, parasitärbehafteten und zeitvarianten Simulationen durchgeführt wird. Bereits bei herkömmlichen Schaltfrequenzen und hartgeschaltetem Betrieb können signifikante Verbesserungen des Wirkungsgrades erreicht werden. Weitergehend wird der Nutzen der durch die GaN-Transistoren ermöglichten höheren Schaltfrequenzen eruiert. Die um bis zu Faktor 20 erhöhte Schaltfrequenz macht den Einsatz einer resonanten Betriebsart (Zero-Voltage-Switching) und einer Luftspule als Hauptinduktivität notwendig. Auf Steuergeräteebene kann somit die Verlustleistung auf unter ein Drittel reduziert werden, was zudem ein deutlich einfacheres und kompakteres Gehäuse ermöglicht, wodurch das Gesamtgewicht etwa halbiert werden kann. Abschließend wird die Schaltung in einem Prototypen praktisch umgesetzt und die Funktionsfähigkeit im ZVS-Betrieb bei Schaltfrequenzen von bis zu 10 MHz verifiziert. / This thesis deals with the research of possibilities for maximising efficiency of current-regulating DC/DC-Converters for driving high-power-LEDs in passenger-car- and motorcycle-lighting-devices. The ambition is to reduce weight and energy-consumption of the electronic-control-units, to contribute to reach the continuously decreasing target-values for vehicle-emissions. Therefor different approaches in topology, components, design and operating mode are considered. A key-challenge for the circuit-design is the common-part-strategy for usage in many individual vehicle-headlamp-systems with a wide range of output-current and LED-string-voltages. Basis for the reduction of power-losses is the simplification of the converters topology in terms of quantity of components. This is achieved by using the 48 V -vehicle-electrical-system as voltage-supply and a step-down-topology. Mainpart of this research is about the potential benefits of applying novel Galliumnitride High-electron-mobility-transistors (GaN-HEMTs) instead of silicon MOS-FETs. Initially this is done by calculations and parasitic-afflicted, timevariant circuit-simulations. Already in hardswitching operation under conventional switching-frequencies significant improvements in converter-efficiency can be achieved. Furthermore the advantages of higher switching-frequencies, offered by the GaN-transistors, are investigated. Up to 20 times higher switching-frequencies necessitate a resonant operating mode of the circuit (Zero-voltage-switching) and the use of an aircoil as main-inductor. On ECU-level power-losses can be reduced down to less than one third, which enables a more simplified and compact housing-concept, so that the overall weight can drop to about the half. Finally the designed circuit is build up in a prototype and the functional capability is verified in ZVS-mode with up to 10 MHz switching-frequency.

Alstom wanted to investigate the possibility of adapting its light emitting diode (LED) technology for shunting signals in train traffic. The LED technology uses 50V, but Alstom wants to adapt it for 12V. The LED technology is energy efficient but needs to be adapted for existing signal interlocking by drawing a higher current. This meant that the possibility of reactive power compensation was investigated to obtain lower thermal dissipation in dwarf signal. The essay presents a couple of possible solutions. One of the solutions is to raise the voltage by using a booster converter to use the existing 50V LED unit. Capacitors were reviewed to be used in reactive power compensation to increase current supply. One of the solutions then became a capacitor bank. Simulations indicated that a booster converter and a capacitor bank can be used to adapt the circuit. However, some modifications must be made. / Alstom ville undersöka möjligheten att anpassa sin lysdiodsteknik för dvärgsignaler i tågtrafiken. Lysdiodstekniken använder 50V men Alstom vill anpassa den för 12V. Lysdiodtekniken är strömsnål och behöver anpassas för befintliga signalställverk genom att dra en högre ström. Detta innebar att möjligheten för reaktiv kompensering undersöktes för att få en låg värmeutvecklingen i dvärgsignalen. I uppsatsen presenteras ett par möjliga lösningar. En av lösningarna för spänningen är en step-up omvandlare för att nyttja 50Vs enheten. Det gjordes också en genomgång av kondensatorer för att nyttjas i reaktivkompensering för att öka strömförbrukningen. En av lösningarna blev då ett kondensatorbatteri. Det kunde konstateras med matematisk simulering att step-up omvandlare och ett kondensatorbatteri kan användas för att anpassa kretsen dock måste vissa modifieringar utföras.

In last years phenomena of wireless communication technologies became a primary interest of big development laboratories whole world. Domain of point to point links which are realized by laser technology with narrow beam divergence and very sensitive photo-detectors is ordinarily used these days. This trend of using light waves as carrier medium turned interests of scientist to the sphere of wide area networks which is domain of wi-fi radio technologies. One of new trends in this sphere is also in-door free space optics. With expansion which leads to using LED's in everyday applications and with technological progress of last years, also grows tendency of most effective utilization of LED systems. The result of this effort is thought which considerate LED as source of artificial lighting and source of carrier medium for modulated signal. This kind of device must fulfill hygienic standards for illumination and also must be able to work with high frequency by which is signal modulated. These systems can provide links with sufficient capacity in order of hundred megabits.