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Dissertations / Theses on the topic 'Light switches'
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Kudernáč, Tibor. "Light-controlled conductance using molecular switches photochromic switches get wired /." [S.l. : Groningen : s.n. ; University Library Groningen] [Host], 2007. http://irs.ub.rug.nl/ppn/304519308.
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Giorgi, David Michael. "Light activated closing and opening switches /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9935442.
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Grimsley, Jonathan Scot. "Light Loss In Single Mode Fiber Optical Switches." Master's thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/37142.
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Light loss in single mode fiber optical switches is investigated. Loss due to reflection, aberration and fiber misalignment are evaluated. A simple model of image to fiber end face overlap for the fiber/lens system is developed. The intensity distribution of light in the fiber and imaging system is assumed to be gaussian. It was found that aberration is a major cause of loss and that fiber misalignment did not cause as much loss as expected. Loss due to reflection is assumed to be minimal due to the presence of anti-reflection coatings on the optical components.Master of Science
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Smith, Brian. "Theoretical Analysis of Avalanche Breakdown in Heterojunction Light Amplifying Optical Switches." Honors in the Major Thesis, University of Central Florida, 1993. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/398.
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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucfBachelors
Engineering
Electrical Engineering
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Fitch, Robert J. "Sunlight readability and luminance characteristics of light-emitting diode push button switches." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4520/.
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Lighted push button switches and indicators serve many purposes in cockpits, shipboard applications and military ground vehicles. The quality of lighting produced by switches is vital to operators' understanding of the information displayed. Utilizing LED technology in lighted switches has challenges that can adversely affect lighting quality. Incomplete data exists to educate consumers about potential differences in LED switch performance between different manufacturers. LED switches from four different manufacturers were tested for six attributes of lighting quality: average luminance and power consumption at full voltage, sunlight readable contrast, luminance contrast under ambient sunlight, legend uniformity, and dual-color uniformity. Three of the four manufacturers have not developed LED push button switches that meet lighting quality standards established with incandescent technology.
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Juvalta, Flurin. "Light-induced waveguides, waveguide arrays and switches in photorefractive LiTaO₃ and Sn₂P₂S₆ /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=18105.
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Wang, Hao. "Artifical Light-Driven Chiral Molecular Switches Based on Halogenated and Cyclic Azo-Binaphthyl Derivatives." Kent State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=kent1586518390107867.
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Blom, Magnus. "Light-Triggered Conformational Switches for Modulation of Molecular Recognition : Applications for Peptidomimetics and Supramolecular Systems." Doctoral thesis, Uppsala universitet, Syntetisk organisk kemi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-267845.
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The main focus of this thesis is on photochemical modulation of molecular recognition in various host-guest systems. This involves the design, synthesis and integration of light-triggered conformational switches into peptidomimetic guests and molecular tweezer hosts. The impact of the switches on guest and host structures has been assessed by spectroscopic and computational conformational analysis. Effects of photochemical structure modulation on molecular recognition in protein-ligand and supramolecular host-guest systems are discussed. Phototriggerable peptidomimetic inhibitors of the enzyme M. tuberculosis ribonucleotide reductase (RNR) were obtained by incorporation of a stilbene based amino acid moiety into oligopeptides between 3-9 residues long (Paper I). Interstrand hydrogen bond probability in the E and Z forms of the peptidomimetics was used as a tool for predicting conformational preferences. Considerable differences in inhibitory potency for the E and Z photoisomers were demonstrated in a binding assay. In order to advance the concept of photomodulable inhibitors, synthetic routes towards amino acid derivatives based on the more rigid stiff-stilbene chromophore were developed (Paper II). The effect of E-Z isomerization on the conformational properties of peptidomimetic inhibitors incorporating the stiff-stilbene chromophore was also assessed computationally (Paper III). It was indicated that inhibitors with the more rigid amino acid derivative should display larger conformational divergence between photoisomers than corresponding stilbene derivatives. Bisporphyrin tweezers with enediyne and stiff-stilbene spacers have been synthesized, and the conformational characteristics imposed by the spacers have been studied and compared to a glycoluril linked tweezer. The effects of spacers on tweezer binding of diamine guests and helicity induction by chiral guests have been investigated (Paper IV). Connections between spacer flexibility and host-guest binding strength have been established. The structural properties of the stiff-stilbene spaced tweezer made it particularly susceptible to helicity induction by both monotopic and bitopic chiral guests. Finally, the possibility of photochemical bite-size variation of tweezers with photoswitchable spacers has been assessed. Initial studies have shown that photoisomerization of the tweezers is possible without photochemical decomposition. Conformational analyses indicate that isomerization should impact binding characteristics of the tweezers to a significant extent (Paper V).
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Lahm, Rudinei Luis da Fonseca. "Análise dos papéis de compra no processo de aquisição de interruptores por clientes finais." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/158357.
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O presente estudo tem como objetivo identificar os papéis na compra de interruptores de luz por clientes finais e identificar as influências desses papéis e como ocorrem. O método utilizado foi dividido em duas fases, a primeira com abordagem qualitativa e a segunda com abordagem quantitativa. Inicialmente foram feitas entrevistas em profundidade com consumidores e profissionais da área, com o objetivo de identificar quais os tipos de papéis que ocorrem durante a compra de interruptores e identificar os influenciadores. O segundo passo foi uma survey, sendo entrevistadas 1.013 pessoas divididas nas cinco regiões do país, Região Centro Oeste, Nordeste, Sul, Norte e Sudeste. Foram identificados cinco papéis de compra e sete influenciadores desse processo. Os resultados da pesquisa quantitativa foram analisados com análises univariadas e multivariadas. As análises indicam que os compradores adquirem interruptores para outros usuários, mas a grande maioria deles adquirem o produto para uso próprio e são responsáveis pela compra e pelo pagamento do produto. Os resultados também indicam que as pessoas próximas são os maiores influenciadores. Espera-se que com os resultados obtidos esse trabalho possa contribuir para executivos e empresas do setor elétrico na tomada de decisões.The present paper has the objective to identify which are the final consumers purchase roles of light switches and identify the influences about this roles and how it occurs. The analysis method was dividing in two steps, the first with a qualitative approach and the second with a quantitative approach. First of all, had been made depth interviews with consumers and professionals from the area, with the objective to identify the influencers. After that, a survey has been made, 1.013 people were interviewed and divided at five regions of the country, Midwest region, Northeast, South, North and Southeast. Were identified five purchase roles and seven influencers of this process. The quantitative research results were analyzed with univariate and multivariate analysis. The analysis indicate that the buyers also buy the light switches for other users, but the majority buy the product for own use and is responsible for the purchase and the product payment. The results also indicate that, in general, close people are the major influencers. With the obtained results throw crossing and the performed analyses, the expectations with this paper is contribute with executives and companies of the area on theirs decision-making.
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Kröner, Dominik (Dr rer nat ). "Analysis and control of light-induced processes in molecules: Electron and nuclear quantum dynamics for aspects of stereoisomerism and spectroscopy." Thesis, Universität Potsdam, 2013. http://opus.kobv.de/ubp/volltexte/2014/7047/.
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The habilitation thesis covers theoretical investigations on light-induced processes in molecules. The study is focussed on changes of the molecular electronic structure and geometry, caused either by photoexcitation in the event of a spectroscopic analysis, or by a selective control with shaped laser pulses. The applied and developed methods are predominantly based on quantum chemistry as well as on electron and nuclear quantum dynamics, and in parts on molecular dynamics. The studied scientific problems deal with stereoisomerism and the question of how to either switch or distinguish chiral molecules using laser pulses, and with the essentials for the simulation of the spectroscopic response of biochromophores, in order to unravel their photophysics. The accomplished findings not only explain experimental results and extend existing approaches, but also contribute significantly to the basic understanding of the investigated light-driven molecular processes. The main achievements can be divided in three parts:
First, a quantum theory for an enantio- and diastereoselective or, in general, stereoselective laser pulse control was developed and successfully applied to influence the chirality of molecular switches. The proposed axially chiral molecules possess different numbers of "switchable" stable chiral conformations, with one particular switch featuring even a true achiral "off"-state which allows to enantioselectively "turn on" its chirality. Furthermore, surface mounted chiral molecular switches with several well-defined orientations were treated, where a newly devised highly flexible stochastic pulse optimization technique provides high stereoselectivity and efficiency at the same time, even for coupled chirality-changing degrees of freedom. Despite the model character of these studies, the proposed types of chiral molecular switches and, all the more, the developed basic concepts are generally applicable to design laser pulse controlled catalysts for asymmetric synthesis, or to achieve selective changes in the chirality of liquid crystals or in chiroptical nanodevices, implementable in information processing or as data storage.
Second, laser-driven electron wavepacket dynamics based on ab initio calculations, namely time-dependent configuration interaction, was extended by the explicit inclusion of magnetic field-magnetic dipole interactions for the simulation of the qualitative and quantitative distinction of enantiomers in mass spectrometry by means of circularly polarized ultrashort laser pulses. The developed approach not only allows to explain the origin of the experimentally observed influence of the pulse duration on the detected circular dichroism in the ion yield, but also to predict laser pulse parameters for an optimal distinction of enantiomers by ultrashort shaped laser pulses. Moreover, these investigations in combination with the previous ones provide a fundamental understanding of the relevance of electric and magnetic interactions between linearly or non-linearly polarized laser pulses and (pro-)chiral molecules for either control by enantioselective excitation or distinction by enantiospecific excitation.
Third, for selected light-sensitive biological systems of central importance, like e.g. antenna complexes of photosynthesis, simulations of processes which take place during and after photoexcitation of their chromophores were performed, in order to explain experimental (spectroscopic) findings as well as to understand the underlying photophysical and photochemical principles. In particular, aspects of normal mode mixing due to geometrical changes upon photoexcitation and their impact on (time-dependent) vibronic and resonance Raman spectra, as well as on intramolecular energy redistribution were addressed. In order to explain unresolved experimental findings, a simulation program for the calculation of vibronic and resonance Raman spectra, accounting for changes in both vibrational frequencies and normal modes, was created based on a time-dependent formalism. In addition, the influence of the biochemical environment on the electronic structure of the chromophores was studied by electrostatic interactions and mechanical embedding using hybrid quantum-classical methods. Environmental effects were found to be of importance, in particular, for the excitonic coupling of chromophores in light-harvesting complex II. Although the simulations for such highly complex systems are still restricted by various approximations, the improved approaches and obtained results have proven to be important contributions for a better understanding of light-induced processes in biosystems which also adds to efforts of their artificial reproduction.Die Habilitationsschrift behandelt theoretische Untersuchungen von durch Licht ausgelösten Prozessen in Molekülen. Der Schwerpunkt liegt dabei auf Veränderungen in der Elektronenstruktur und der Geometrie der Moleküle, die durch Bestrahlung mit Licht entweder bei einer spektroskopischen Untersuchung oder bei gezielter Kontrolle durch geformte Laserpulse herbeigeführt werden. Um die dabei auftretende Elektronen- und Kerndynamik zu simulieren, wurden vornehmlich quantentheoretische Methoden eingesetzt und weiterentwickelt. Die wissenschaftlichen Fragestellungen beschäftigen sich mit dem gezielten Verändern und dem Erkennen der räumlichen Struktur von Molekülen ohne Drehspiegelachse, der sog. molekularen Chiralität, sowie mit durch Licht eingeleiteten Prozessen in biologisch relevanten Pigmenten auf sehr kurzen Zeitskalen. Die entwickelten Ansätze und gewonnenen Erkenntnisse lassen sich drei Haupterfolge unterteilen: Erstens gelang die Entwicklung einer generellen Kontrolltheorie für das Ein- und Umschalten von molekularer Chiralität mit geformten Laserpulsen. Dabei wird die räumliche Struktur der vorgeschlagenen molekularen Schalter zwischen ihren stabilen sog. stereoisomeren Formen selektiv geändert, was sich auf ihre optischen und chemischen Eigenschaften auswirkt. Für komplexere Bedingungen, wie z.B. auf einer Oberfläche verankerten molekularen Schaltern verschiedener Orientierung, wurde eine neue Pulsoptimierungsmethode basierend auf Wahrscheinlichkeiten und Statistik entwickelt. Solche laserpulskontrollierten chiralen molekularen Schalter hofft man u.a. in der Nanotechnologie zum Einsatz zu bringen, wo sie z.B. als Informationsspeicher dienen könnten. Zweitens konnte geklärt werden, welche die wesentlichen Einflüsse sind, die das Erkennen von sog. Enantiomeren, das sind spiegelbildliche Moleküle von entgegengesetzter Chiralität, nach Ionisierung durch ultrakurze zirkular polarisierte Laserpulse ermöglichen. Diese Form des sog. Zirkulardichroismus in der Ionenausbeute erlaubt die quantitative und qualitative Unterscheidung von Enantiomeren in der Massenspektrometrie. Durch Simulation der Elektronendynamik während der Laseranregung konnte u.a. erstmals gezeigt werden, dass neben der Zirkularpolarisation der Laserpulse vor allem die schwachen magnetischen Wechselwirkungen für die Unterscheidung entscheidend sind. Drittens wurden die Spektren von in der Natur vorkommenden Pigmenten simuliert, welche u.a. an wichtigen biologischen Funktionen, wie dem Sammeln von Sonnenenergie für die Photosynthese, beteiligt sind. Die Lichtanregung führt dabei zu einer Veränderung der Elektronenstruktur und Geometrie der Pigmente, wobei letzteres wichtige Konsequenzen für die Verteilung der Energie auf die spektroskopisch beobachteten Molekülschwingungen mit sich bringen. Auch der wichtige Einfluss der biochemischen Umgebung auf die Elektronenstruktur der Pigmente bzw. den Energietransfer zwischen solchen wurde untersucht. Neben der Klärung experimenteller Ergebnisse ermöglichen die Untersuchungen neue Einblicke in die fundamentalen Prozesse kurz nach der Lichtanregung -- Erkenntnisse, die auch für die technische Nachahmung der biologischen Funktionen von Bedeutung sein können.
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Goldberg, Benjamin. "Benchmarking Traffic Control Algorithms on a Packet Switched Network." Scholarship @ Claremont, 2015. http://scholarship.claremont.edu/cmc_theses/1192.
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Traffic congestion has tremendous economic and environmental costs. One way to reduce this congestion is to implement more intelligent traffic light systems. There is significant existing research into different algorithms for controlling traffic lights, but they all use separate systems for performance testing. This paper presents the Rush Hour system, which models a network of roadways and traffic lights as a network of connected routers and endnodes. Several traffic switching algorithms are then tested on the Rush Hour system. As expected, we found that the more intelligent systems were effective at reducing congestion at low and medium levels of traffic. However, they were comparable to more naive algorithms at higher levels of traffic.
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Bremer, Matthias [Verfasser]. "Functionalized photochromic surfaces switched by organic light-emitting diodes / Matthias Bremer." Kiel : Universitätsbibliothek Kiel, 2018. http://d-nb.info/1154434001/34.
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Hussein, Ali Abdulsattar. "Photonic Integrated Circuits Utilizing Nano-Electromechanical Systems on Silicon-on-Insulator Platform for Software Defined Networking in Elastic Optical Networks: New Insights Into Phased Array Systems, Tunable WDM, and Cascaded FIR and IIR Architectures." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39592.
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Optical communications systems operate at the limits of their margins to respond to increasing capacity demands. Some of the signal processing functions required must soon operate at speeds beyond electronic implementation. Optical signal processors are fundamentally analog which requires precise control of the operating state. Programmable optical components are consequently essential. The thesis explores and elucidates the properties of meshes of generalized Mach-Zehnder interferometers (GMZIs) amenable to silicon (Si) photonics integration that are based on multimode interference couplers with programmability achieved via voltage controlled phase-shift elements within the interferometer arms to perform a variety of finite impulse response (FIR) and infinite impulse response (IIR) signal processing functions.
The thesis presents a novel class of integrated photonic phased array systems with a single-stage, multistage, and feedback architectures. The designed photonic integrated systems utilize nano-electromechanical-system (NEMS) operated phase shifters of cascaded free suspended slot waveguides that are compact and require a small amount of power to operate. The structure of the integrated photonic phased array switch (IPPAS) elements is organized such that it brings the NEMS-operated phase shifters to the exterior sides of the construction; facilitating electrical connection. The transition slot couplers used to interconnect the phase shifters to the rest of the silicon structure are designed to enable biasing one of the silicon beams of each phase shifter from an electrode located at the side of the phase shifter. The other silicon beam of each phase shifter is biased through the rest of the silicon structure of the fabric, which is taken as a ground. Phased array processors of 2×2 and 4×4 multiple-input-multiple-output (MIMO) ports are conveniently designed within reasonable footprints native to the current fabrication technologies. The response of the single-stage 4×4 broadband IPPAS element is determined, and its phase synthesis states required for single-throw, double-throw and broadcast routing operations are predicted. The transmission responses of the single-stage wavelength division multiplexing (WDM) processors of 2×2 and 4×4 MIMO ports are simulated. The wavelength steering capability of the transmission interferograms by applying progressive phase shifts through the array of NEMS-operated phase shift elements of the single-stage 4×4 WDM (de)multiplexer is demonstrated.
The advantages of cascading broadband and WDM phased array sections are articulated through several study cases. Five different cascaded phased array architectures are trialed for the construction of non-blocking 4×4 IPPAS broadband switches that are essential elements in the construction of universal photonic processors. A cascaded 2×2 WDM (de)multiplexer that can set the bandwidth of the (de)multiplexed cyclic channels into a binary number of programmable values is demonstrated. The envelope and wavelength modulations of the transmission responses utilizing a cascaded forward structure of three 2×2 sections that can be utilized for the (de)multiplexing of different bandwidth channels are demonstrated providing individual wavelength steering capability of the narrowband and wideband channels and the individual wavelength steering capability of the slow envelope and wavelength modulating functions. Innovative universal 2×2 and 4×4 cascaded phased array processors of advanced high-order architectures that can function as both non-blocking broadband routers and tunable WDM (de)multiplexers with spectrum steering and bandwidth control of the (de)multiplexed demands are introduced.
The multimode interference (MMI) coupler is utilized for the construction of several IIR feedback photonic processors. Tunable photonic feedback processors have the advantage of using less number of MMI couplers compared to their counterparts of FIR forward-path processors saving on the footprint and loss merits. A passive feedback 2×2 (de)multiplexer made of a 4×4 MMI coupler and two loopback paths is proposed. The inclusion of an imbalance in the lengths of the loopback paths of the same symmetrical feedback (de)multiplexer is demonstrated to achieve wavelength modulation of the (de)multiplexed transmission responses that are useful for the (de)multiplexing of different bandwidth channels. Several newly introduced IIR feedback architectures are demonstrated to function similarly as their counterparts of FIR forward-path processors as binary bandwidth variable (de)multiplexers, envelope and wavelength modulation (de)multiplexers, and universal feedback processors.
The investigation provided in this thesis is also supported with dynamic zero-pole evolution analysis in the complex plane of analysis of the studied FIR and IIR photonic processors to enhance understanding the principle of operation. This research expands the prospective for constructing innovative silicon-on-insulator (SOI) based optical processors for applications in modern optical communication systems and programmable elastic optical networks (EONs).
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Nuttall, Daniel Robert. "Advanced high frequency switched-mode power supply techniques and applications." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/advanced-high-frequency-switchedmode-power-supply-techniques-and-applications(5792cb86-58e3-488b-b27e-559c18e55250).html.
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This Thesis examines the operation and dynamic performance of a single-stage, single-switch power factor corrector, S4 PFC, with an integrated magnetic device, IM. Also detailed isthe development and analysis of a high power light emitting diode, HP LED, power factorcorrection converter and proposed voltage regulation band control approach.The S4 PFC consists of a cascaded discontinuous current mode, DCM, boost stage anda continuous current mode, CCM, forward converter. The S4 PFC achieves a high powerfactor, low input current harmonics and a regulated voltage output, utilising a singleMOSFET. A steady-state analysis of the S4 PFC with the IM is performed, identifying theoperating boundary conditions for the DCM power factor correction stage and the CCMoutput voltage regulation stage. Integrated magnetic analysis focuses on understanding theperformance, operation and generated flux paths within the IM core, ensuring the device doesnot affect the normal operation of the converter power stage. A design method for the S4 PFCwith IM component is developed along with a cost analysis of this approach. Analysis predictsthe performance of the S4 PFC and the IM, and the theoretical work is validated by MATLABand SABER simulations and measurements of a 180 W prototype converter.It is not only the development of new topological approaches that drives theadvancement of power electronic techniques. The recent emergence of HP LEDs has led to aflurry of new application areas for these devices. A DCM buck-boost converter performs thepower factor correction and energy storage, and a cascaded boundary conduction current modebuck converter regulates the current through the LED arrays. To match the useful operatinglifetime of the HP LEDs, electrolytic capacitors are not used in the PFC converter. Analysisexamines the operation and dynamic characteristics of a PFC converter with low capacitiveenergy storage capacity and its implications on the control method. A modified regulationband control approach is proposed to ensure a high power factor, low input current harmonicsand output voltage regulation of the PFC stage. Small signal analysis describes the dynamicperformance of the PFC converter, Circle Criterion is used to determine the loop stability.Theoretical work is validated by SABER and MATLAB simulations and measurements of a180 W prototype street luminaire.
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McKinley, Andrew W. "Photophysics of light switch ruthenium complexes and their interactions with DNA." Thesis, University of Newcastle Upon Tyne, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492080.
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The luminescent DNA probe [Ru(phen)2dppz]2+, ruthenium (bis-1,10-phenanthroline di-pyrido-[3,2-a:2',3'-c]phenazine), was the first tris-bidentate ruthenium complex to be shown unequivocally to intercalate DNA, which it achieves via insertion of the extended dipyridophenazine (dppz) ligand. The complex is non-luminescent in aqueous solution but emits strongly in organic solvents, micelles and DNA, with a quantum yield that depends on polarity, H-bonding, and protic ability of the medium. Studies of complexes with methylated dppz derivatives in a range of solvents have shown that a number of solvent factors influence the luminescent switching behaviour, the most intriguing of which is the implication of hydrogen bond formation between the dppz ligand and solvent molecules.
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Zhang, Tao, Tao Chen, Ihsan Amin, and Rainer Jordan. "ATRP with a light switch: photoinduced ATRP using a household fluorescent lamp." Royal Society of Chemistry, 2014. https://tud.qucosa.de/id/qucosa%3A36423.
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Photoinduced atom transfer radical polymerization (ATRP) was achieved using a simple household fluorescent lamp as the light source. In solution, methyl methacrylate could be polymerized to welldefined polymers; the photoinduced ATRP system did only convert monomers during irradiation and was inactive in the dark. In situ monitoring by UV-vis spectroscopy revealed the photoredox cycle between Cuᶦᶦ and Cuᶦ species. The linear development of the polymer number average molar mass with monomer conversion, the low dispersity as well as chain extension experiments showed the controlled nature of the polymerization. Photoinduced ATRP was also used to prepare homo- and block copolymer brushes and patterned brushes on surfaces by photoinduced surface-initiated ATRP (PSI-ATRP).
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Torrijos, Morán Luis. "Photonic Applications Based on Bimodal Interferometry in Periodic Integrated Waveguides." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/172163.
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Tesis por compendio[ES] La fotónica de silicio es una tecnología emergente clave en redes de comunicación e interconexiones de centros de datos de nueva generación, entre otros. Su éxito se basa en la utilización de plataformas compatibles con la tecnología CMOS para la integración de circuitos ópticos en dispositivos pequeños para una producción a gran escala a bajo coste. Dentro de este campo, los interferómetros integrados juegan un papel crucial en el desarrollo de diversas aplicaciones fotónicas en un chip como sensores biológicos, moduladores electro-ópticos, conmutadores totalmente ópticos, circuitos programables o sistemas LiDAR, entre otros. Sin embargo, es bien sabido que la interferometría óptica suele requerir caminos de interacción muy largos, lo que dificulta su integración en espacios muy compactos. Para mitigar algunas de estas limitaciones de tamaño, surgieron varios enfoques, incluyendo materiales sofisticados o estructuras más complejas, que, en principio, redujeron el área de diseño pero a expensas de aumentar los pasos del proceso de fabricación y el coste. Esta tesis tiene como objetivo proporcionar soluciones generales al problema de tamaño típico de los interferómetros ópticos integrados, con el fin de permitir la integración densa de dispositivos basados en silicio. Para ello, aunamos los beneficios tanto de las guías de onda bimodales como de las estructuras periódicas, en términos de la mejora del rendimiento y la posibilidad para diseñar interferómetros monocanal en áreas muy reducidas. Más específicamente, investigamos los efectos dispersivos que aparecen en estructuras menores a la longitud de onda y en las de cristal fotónico, para su implementación en diferentes configuraciones interferométricas bimodales. Además, demostramos varias aplicaciones potenciales como sensores, moduladores y conmutadores en tamaños ultra compactos de unas pocas micras cuadradas. En general, esta tesis propone un nuevo concepto de interferómetro integrado que aborda los requisitos de tamaño de la fotónica actual y abre nuevas vías para futuros dispositivos basados en funcionamiento bimodal.
[CA] La fotònica de silici és una tecnologia emergent clau en xarxes de comunicació i interconnexions de centres de dades de nova generació, entre altres. El seu èxit es basa en la utilització de plataformes compatibles amb la tecnologia CMOS per a la integració de circuits òptics en dispositius diminuts per a una producció a gran escala a baix cost. Dins d'aquest camp, els interferòmetres integrats juguen un paper crucial en el desenvolupament de diverses aplicacions fotòniques en un xip com a sensors biològics, moduladors electro-òptics, commutadors totalment òptics, circuits programables o sistemes LiDAR, entre altres. No obstant això, és ben sabut que la interferometría òptica sol requerir camins d'interacció molt llargs, la qual cosa dificulta la seua integració en espais molt compactes. Per a mitigar algunes d'aquestes limitacions de grandària, van sorgir diversos enfocaments, incloent materials sofisticats o estructures més complexes, que, en principi, van reduir l'àrea de disseny però a costa d'augmentar els processos de fabricació i el cost. Aquesta tesi té com a objectiu proporcionar solucions generals al problema de grandària típica dels interferòmetres òptics integrats, amb la finalitat de permetre la integració densa de dispositius basats en silici. Per a això, combinem els beneficis tant de les guies d'ones bimodals com de les estructures periòdiques, en termes de funcionament d'alt rendiment per a dissenyar interferòmetres monocanal compactes en àrees molt reduïdes. Més específicament, investiguem els efectes dispersius que apareixen en estructures menors a la longitud d'ona i en les de cristall fotònic, per a la seua implementació en diferents configuracions interferomètriques bimodals. A més, vam demostrar diverses aplicacions potencials com a sensors, moduladors i commutadors en grandàries ultres compactes d'unes poques micres cuadrades. En general, aquesta tesi proposa un nou concepte d'interferòmetre integrat que aborda els requisits de grandària de la fotònica actual i obri noves vies per a futurs dispositius basats en funcionament bimodal.
[EN] Silicon photonics is a key emerging technology in next-generation communication networks and data centers interconnects, among others. Its success relies on the ability of using CMOS-compatible platforms for the integration of optical circuits into small devices for a large-scale production at low-cost. Within this field, integrated interferometers play a crucial role in the development of several on-chip photonic applications such as biological sensors, electro-optic modulators, all-optical switches, programmable circuits or LiDAR systems, among others. However, it is well known that optical interferometry usually requires very long interaction paths, which hinders its integration in highly compact footprints. To mitigate some of these size limitations, several approaches emerged including sophisticated materials or more complex structures, which, in principle, reduced the design area but at the expense of increasing fabrication process steps and cost. This thesis aims at providing general solutions to the long-standing size problem typical of optical integrated interferometers, in order to enable the densely integration of silicon-based devices. To this end, we combine the benefits from both bimodal waveguides and periodic structures, in terms of high-performance operation and compactness to design single-channel interferometers in very reduced areas. More specifically, we investigate the dispersive effects that arise from subwavelength grating and photonic crystal structures for their implementation in different bimodal interferometric configurations. Furthermore, we demonstrate various potential applications such as sensors, modulators and switches in ultra-compact footprints of a few square microns. In general, this thesis proposes a new concept of integrated interferometer that addresses the size requirements of current photonics and open up new avenues for future bimodal-operation-based devices.
Financial support is also gratefully acknowledged through postdoctoral FPI grants from Universitat Politècnica de València (PAID-01-18). European Commission through the Horizon 2020 Programme (PHC-634013 PHOCNOSIS project). The authors acknowledge funding from the Generalitat Valenciana through the AVANTI/2019/123, ACIF/2019/009 and PPC/2020/037 grants and from the European Union through the operational program of the European Regional Development Fund (FEDER) of the Valencia Regional Government 2014–2020.
Torrijos Morán, L. (2021). Photonic Applications Based on Bimodal Interferometry in Periodic Integrated Waveguides [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172163
TESIS
Compendio
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Mlitan, Adel M. "Synthesis of mono transition metal complexes that tuning the photophysical property of DNA light switch." Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.554927.
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A Series of ruthenium(II)-(tpm)(dppz), (phen) and (dppn) complexes have been synthesised which have been designed to show binding to DNA. These complexes have been characterized by a wide range of techniques, including X-ray crystallography. The binding of the complexes with CT-DNA sequence has been studied using a variety of techniques, including, UV-Vis, luminescence and CD spectroscopy as well as viscometry. hi most of the cases, the metal complexes stabilise DNA, bind via intercalation and their binding affinities with CT-DNA are in the micromolar range. We have observed a remarkable modulation of the binding of our complexes to DNA by changing the ancillary ligands of the complex. As a comparison DNA binding properties of some Ru(II)-(tpy)(dppz) and Ru(II)-(tpy)(phen) complexes synthesised in the same way were also explored. These metal complexes stabilise DNA and viscosity measurements also shows intercalation between base pairs.
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Johnston, Wesley James. "Nonlinear optics in Bragg-spaced quantum wells." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/826.
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Bragg spaced quantum wells represent a unique class of resonant photonic materials, wherein a photonic bandgap is created by the periodic spacing of quantum wells and the associated variation in the complex susceptibility (index and absorption) of the material. Interest in BSQWs has grown in the past decade due to their large ultrafast nonlinearities and the corresponding large ultrafast reflectivity changes and transmissivity. These nonlinearities are of particular interest in areas of communication technology, where ultrafast all-optical logic components have become increasingly in demand. This research will further investigate BSQWs and the for the first time effects of spin-dependent nonlinear excitation on their photonic band structures. It will also investigate how these effects can be used in all-optical polarization switching and tunable optical buffer (slow light) applications.
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Steller, Laura, Renate Schulze, Wolf D. Habicher, Thomas Wolff, Gerald Steiner, and Reiner Salzer. "Die Entwicklung eines lichtgesteuerten Molekularschalters - ein Nanobauteil für den Einsatz in funktionellen Schaltkreisen und Nanomaschinen." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1188380737319-72281.
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Our target is the engineering of a light-gate molecular switch for the artificial ion channel, which will enable artificial ion channels to operate successfully in microfluidic systems, biomimetic sensors and various technical devices. A stable but reversible switch mechanism design is crucial, because the artificial ion channels known to date are lacking any control mechanism. Our artificial molecular switch is divided in two parts: the body part (calixarene) and a gate part based on light-responsive azo groups. The key to the controlling mechanism is the conformational change between cis and trans isomers, which is translated into movement of the gate. The gate is very robust and can either block or let the ions pass the molecular switch. Patch clamp investigations indicate successful integrations of gated artificial ion channels into lipid membranesUnser Ziel ist die Entwicklung eines lichtinduzierten Molekularschalters für künstliche Ionenkanäle, der als Nanobauteil für die Entwicklung von Sensoren in mikrofluiden Systemen, in biomimetischen Sensoren und in verschiedenen technischen Baugruppen eingesetzt werden soll. Für ein stabiles und zugleich reversibles System ist der Schaltmechanismus entscheidend, da die künstlichen Ionenkanäle bisher – soweit bekannt – keinen Regelmechanismus besitzen. Unser künstlicher molekularer Schalter setzt sich aus einem Rumpfteil (Calix[4]resorcinaren) und einer Schalteinheit, basierend auf lichtempfindlichen Azogruppen, zusammen. Die Schalteinheit ist sehr widerstandsfähig, kann den Ionenfluss blockieren oder die Ionen durch den Ionenkanal passieren lassen. Durch Bestrahlung wird die Kanalaktivität unterdrückt und reversibel wiederbelebt. Mittels Patch-Clamp-Untersuchungen wird das Schalten der synthetischen Ionenkanäle überprüft
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Izquierdo, Serra Mercè. "Photoswitchable glutamate receptors to control neurotransmission with light." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/146130.
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Optical tools to control neuronal activity include synthetic photoswitchable ligands of receptors and ion channels. Photoswitches can act either as soluble molecules (photochromic ligands, PCLs) or tethered to the protein (photoswitchable tethered ligands, PTLs), and they have been used to photocontrol many ion channels and receptors such as voltage-gated potassium channels, acetylcholine or glutamate receptors. Recognizing both the need for new optical tools in neuroscience and the opportunities offered by photoswitches, this work is focused on the use of light gated glutamate receptors to control neuronal activity and neurotransmission.
In the first chapter of results of the thesis, we demonstrate that the Ca2+-permeable LiGluR can be used as a tool to reversibly control neurosecretion by directly affecting the intracellular [Ca2+]. To achieve this goal, LiGluR was expressed in cultured bovine chromaffin cells and cultured hippocampal neurons. We measured secretion in chromaffin cells using two techniques, amperometry and membrane capacitance, and current-clamp recordings to assess neurotransmission in cultured neurons. The results indicated that the magnitude of LiGluR-mediated Ca2+ influx is sufficiently large to trigger regulated exocytosis in chromaffin cells and neurons. In addition, LiGluR induced secretion can be modulated with the wavelength of illumination. This new application of LiGluR opens the possibility to reversibly control the activity of individual synapses, which might help to understand the computational properties of neurons and to unravel how brain circuits work.
To use LiGluR as an effective method to interrogate the neuronal function it should support high-spatial 3D resolution and tissue penetration. Multiphoton excitation with near-infrared light enables stimulation in intact tissue with cellular and subcellular resolution, and it has been extensively applied to optical actuators such as caged compounds and more recently to optogenetics. However, two-photon stimulation of synthetic photoswitches had not been explored before. In the second section of the results, the two-photon stimulation of LiGluR is investigated. Two new photoswitches were designed (MAG2p and MAGA2p) based on the structure of the original photoswitch (MAG) and intended to enhance the two-photon absorption ability of the azobenzene switch. The three PTLs, including MAG, successfully activate LiGluR under two-photon stimulation, suggesting that multiphoton excitation can be applied to other azobenzene-based molecules. Interestingly, the rationally designed photoswitches were more efficient in opening LiGluR as lower power and shorter simulation time were required. Finally we validated MAG2p and MAG as new tools to control the activation of neurons and astrocytes with cellular and subcellular resolution.
In the last chapter, a new method based on the affinity labeling approach is presented in order to confer light sensitivity to endogenous receptors. Glutamate-azobenzene-reactive PTLs with different lengths and reactive groups were tested on kainate receptors. These reactive PTLs successfully and functionally conjugate to the ionotropic glutamate receptor subunit GluK1, thus enabling to photoswitch its activity, as evidenced from photocurrent recordings of mammalian cells overexpressing the non-mutated receptor. These results are also supported by the photocontrol of GluK1 currents in dorsal root ganglion neurons, where GluK1 is the main glutamate subunit that is endogenously expressed. The new strategy proposed is versatile and we suggest that it can be extended to label other endogenous receptors, giving rise to novel optpharmacological therapies.
The new methods here developed improve the LiGluR performance, and address photoswitches to use endogenous neuronal receptors to optically control neuronal activity, being able to stimulate them in small volumes corresponding to the neuronal functional unit (i.e. synaptic terminals). In this way, light would emerge as a unique tool to dissect neuronal physiology and to understand the function of neuronal circuits.L’estudi de la neurotransmissió requereix noves eines moleculars, i els fotocommutadors ofereixen grans possibilitats. Aquesta tesi està centrada en l’ús de receptors de glutamat activables per llum (LiGluRs) pel control de l’activitat neuronal i dels processos de neurosecreció. Al primer bloc de resultats, la permeabilitat a Ca2+ dels receptors de glutamat s’aprofita per manipular de manera directa -independentment del voltatge de membrana- i reversible la concentració intracel•lular de Ca2+ amb llum. Així, és possible desencadenar els processos de secreció en cèl•lules cromafins i de neurotransmissió en neurones hipocampals. A la segona part dels resultats de la tesi, s’investiga l’estimulacio multifotó del receptor de glutamat modificat químicament amb fotocommutadors basats en l’azobenzè. Els resultats mostren l’estimulació per dos fotons del LiGluR, incloent-hi dos fotocommutadors nous, que milloren l’absorció multifotó del commutador azobenzè. Finalment, s’aplica aquesta tècnica per estimular neurones i astròcits amb una resolució a l’escala d’una cèl•lula o de compartiment subcel•lular. Al tercer capítol dels resultats, es descriu un nou mètode per aconseguir el fotocontrol de receptors neuronals endògens, utilitzant lligands covalents. Amb l’aplicació d’aquest mètode es pot fotocommutar l’activitat del receptor de kainat subtipus 1 (GluK1) no mutant, quan se sobreexpressa el receptor en cèl•lules de mamífer. Aquesta estratègia també permet obtenir fotocorrents en cultius de neurones dels ganglis de l’arrel dorsal, on GluK1 és la subunitat de glutamat endògenament més expressada. Els nous mètodes desenvolupats en aquesta tesi milloren la utilització dels LiGluRs, encaminant l’ús dels fotocommutadors cap al control òptic dels receptors endògens, amb la possibilitat d’estimular cèl•lules individuals o estructures subneuronals, fet que situaria els fotocomutados com a eines indispensables per l’estudi del cervell, des de la fisiologia fins als circuits neuronals.
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TARHAN, Muhammed Mustafa. "Assessment and Development of Advanced Power Saving and Supply Concepts For Small Automotive Electronics." Thesis, Mittuniversitetet, Avdelningen för elektronikkonstruktion, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-23588.
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With rising fuel prices, increasing electrification, and imminent fines on CO2 emission within the EU, the requirement for energy and cost efficient supply concepts is becomingmore and more important in the automotive industry. This thesis presents an assessmentof, and improvement for energy and cost efficient power supply concepts for low-end automotiveand light e-mobility electronic control units, containing small µCs, and analogand logic components. Specifically, linear regulators, synchronous and non-synchronous buck converters, andswitched capacitor converters are investigated and assessed theoretically. The mostpromising concept, namely a discrete buck converter, is further studied using theoreticalassessment, experiment, and simulations. The key result of this work is a concept for replacing commonly used linear regulatorsin small electronic control units (ECUs) by a more efficient supply with only a smallcost adder. Specifically, since no low-end switched converter ICs are available today, wedeveloped a buck converter with discrete control circuit. This concept provides a cheap,yet efficient alternative to linear regulators for a wide range of applications. In addition,the application of this concept is supported by component selection criteria, and also bythe developed simulation models.
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Boisdenghien, Arnaud. "Photophysique et photochimie de complexes de Ru(II) en présence d'acides nucléiques, d'acides aminés et des biopolymères correspondants." Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210643.
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Les complexes polyazaaromatiques de ruthénium (II) présentent un certain nombre de propriétés remarquables qui conduisent à des applications aussi variées que l'élaboration d'agents anticancéreux, l'inhibition de l'activité de certaines protéines ou encore la conversion d'énergie solaire en énergie chimique. Au cours de ce travail, nous avons exploré en partie chacune de ces trois thématiques. Dans la première partie, nous avons synthétisé un nouveau complexe polyazaaromatique de ruthénium (II), le [Ru(phen)2(HATPHE)]2+. Ce complexe se différencie du [Ru(phen)2(PHEHAT)]2+ qui possède les trois mêmes ligands car dans ce cas, le PHEHAT est chélaté au ruthénium via son second site de chélation. Cette différence, apparemment anodine, se traduit par une modification drastique des propriétés photophysiques du complexe. Alors que le [Ru(phen)2(PHEHAT)]2+ n'émet pas dans l'eau et ne s'aligne pas sur la droite de corrélation spectroélectrochimique, le [Ru(phen)2(HATPHE)]2+ se comporte comme la plupart des autres complexes de Ru(II). En étudiant et en comparant les propriétés photophysiques de ces deux complexes, nous sommes parvenus à rationaliser leurs différences et à proposer un schéma qui reprend leurs différents états excités. Parallèlement, le comportement du [Ru(phen)2(HATPHE)]2+ a été examiné en présence de polynucléotides. L'un deux, l'ADN- (double brin d'oligonucléotide fermé à ses deux extrémités), nous a permis de démontrer l'importance de la déformation de la double hélice lors de l'intercalation d'un ligand plan étendu entre les paires de bases d'un polynucléotide. La deuxième partie de ce travail est consacrée à la photochimie d'un complexe Ru-TAP en présence d'un acide aminé. Cette étude fondamentale a permis de mettre en évidence la formation d'un photoadduit entre le [Ru(TAP)2(phen)]2+ et le tryptophane. Nous avons également étudié les mécanismes qui régissent la synthèse de cet adduit par le biais de l'étude cinétique de la formation et de la recombinaison des espèces transitoires générées au cours de la photoréaction. Enfin, la troisième partie est consacrée à la synthèse et l'étude spectroscopique de complexes trinucléaires de ruthénium (II), l'un d'entre-eux pouvant servir de dendron pour la synthèse de composés de plus haute nucléarité. L'étude des propriétés photophysiques de ces complexes utilisant le PHEHAT comme ligand pontant, nous a permis de mettre en évidence un transfert d'électron intramoléculaire de l'extérieur vers l'intérieur pour un de ces trois composés. Cette propriété est particulièrement intéressante pour la synthèse de nouvelles antennes collectrices d'énergie lumineuse.Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Bender, Vitor Cristiano. "Modelagem e acionamento de diodos orgânicos emissores de luz (OLEDs) para sistemas de iluminação." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/3691.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThis thesis presents the study and characterization of organic light-emitting diodes (OLEDs) with the proposal of obtaining an equivalent model that is useful in the OLED driver design and in lighting systems projects. Initially, a literature review covering the operating principle and the constructive aspects of OLEDs is presented. From this, a model that integrates scale, photometrical, electrical and thermal aspects is proposed. This model is static and dynamic and is called EFET. A procedure for parameter identification of the model is proposed, jointly with an analysis of the intrinsic capacitance effect on the OLED electrical, thermal and photometrical performance. The proposed model is able to predict and simulate the OLED based lighting systems before building, saving time and cost. The model is validated using different OLED samples and conclusions are derived from the experimental validation and simulation results. An approach considering the dimming methods of OLEDs is presented, showing the chromatic impact caused by each method. Finally, an OLED driver based on the concept of switched capacitor converters is proposed. The thesis results are satisfactory and provide an enhancement to the state of the art in modeling and OLED driving.
A presente tese de doutorado apresenta o estudo e a caracterização de diodos orgânicos emissores de luz (OLEDs) com a proposta de um modelo equivalente que é útil no desenvolvimento de circuitos de acionamento e na análise de OLEDs, quando aplicados em sistemas de iluminação. Inicialmente, é apresentada uma revisão bibliográfica contemplando o princípio de funcionamento e os aspectos construtivos dos OLEDs. A partir disto, um modelo que integra os aspectos de escala, fotométricos, elétricos e térmicos é proposto. Esse modelo é denominado EFET e é dividido em estático e dinâmico. Uma proposta de procedimento para identificação dos parâmetros do modelo é apresentada, juntamente com a análise do efeito da capacitância intrínseca dos OLEDs no seu desempenho elétrico, térmico e fotométrico. Com o modelo proposto pode-se predizer e simular o comportamento dos OLEDs antes de construir o sistema de iluminação, reduzindo custos e tempo de desenvolvimento. O modelo é validado empregando diferentes amostras de OLEDs. Conclusões são obtidas a partir da validação experimental e de simulações empregando simuladores elétricos e da fluidodinâmica computacional através do método de elementos finitos. Uma abordagem considerando os métodos de ajuste da intensidade luminosa de OLEDs é apresentada, evidenciando o impacto cromático provocado por cada método. Por fim, um circuito de acionamento para OLEDs baseado no conceito de capacitores chaveados é proposto. Os resultados obtidos são satisfatórios e proporcionam um incremento ao estado da arte da modelagem e acionamento de OLEDs.
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Wu, Hsin-Tai, and 吳欣泰. "Fault Analysis of Low Voltage Street Light Switches." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/ajs4j7.
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碩士國立高雄應用科技大學
電機工程系博碩士班
102
Currently, the street light system were managed by Taiwan Power Company that includes power supply, vanishing point control, repairing and maintenance. The street light system adopted parallel power supply and serial control in Taiwan, but the maintenance relys on manual handling work. Recently, Taiwan Power Company reflects that the street light switches always breakdown in Low Voltage System, and lead to the workers repairing frequently. The purpose of this study is to analyze the damage reason for the street light switches that Taiwan Power Company used. The first step is to collect the damaged cases of street light switches and discuss the design of the street light switches circuit and component specification. Besides, Using Equipment to make an experiment on surge test, temperature, and humidity for analyzing the street light switches in different environment. Finally, to select the monitoring place by the information, and building the real-time street light switch monitoring system. Though the GPRS Wireless communication technology, the information which includes voltage, current, temperature, and humidity will send back to data server, and display on the website. In the future, user can take the historical information to diagnosis by exporting the run chart to analyze the voltage, current, temperature and humidity. Keywords：Street Light Switch, Component Specification, Surge Test
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Zhang, Yi Shu, and 張義樹. "Ultrafast photoconductive switches and their application in light detection." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/92784648557316589029.
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Chien-Yu, Lien. "Theoretical Study of All-Optial Switches Utilizing Storage and Retrieval Light Pulses." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0016-1303200709313283.
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Lien, Chien-Yu, and 連健宇. "Theoretical Study of All-Optial Switches Utilizing Storage and Retrieval Light Pulses." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/94261655606938923812.
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"Functionalized Luciferins for Applications in Supramolecular Chemistry: Development Towards In Vivo Light Switches." Tulane University, 2017.
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Beránek, Radim [Verfasser]. "From photocatalysis to optoelectronic switches : studies of visible light active photoelectrodes based on surface-modified titanium dioxide / vorgelegt von Radim Beránek." 2007. http://d-nb.info/985633077/34.
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CHIEN, DA-EN, and 錢大恩. "Tuning the "Light Switch"." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/10165976247830465090.
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碩士國立臺灣師範大學
化學系
94
Abstract Complex Ru(bpy)2dppz2+ (dppz: dipyrido[3,2-a:2’,3’-c]phenazin) is a well-known "light switch." After irradiation, it exhibits intense emission in nonaqueous solution, but no emission in aqueous solution. The lifetimes for Ru(bpy)2dppz2+, Ru(dcbpy)2dppz2+, Ru(Cl2bpy)2dppz2+, Ru(tmbpy)2dppz2+ and Ru(dmbpy) 2dppz2+ are 759, 1297, 777, 146 and 264 ns in organic solvent, and 38, 951, 777, 7 and 15 ns in 10% H2O solution, respectively. Complexes Ru(bpy)2dppz2+, Ru(dmbpy)2dppz2+ and Ru(tmbpy)2dppz2+ have similar behavior that the emission is almost completely quenched at 10% water added. The emission intensity of Ru(Cl2bpy)2dppz2+ decreases graduately with increasing water amount up to 50%. Complex Ru(dcbpy)2dppz2+ has lifetime of 80 ns in aqueous solution. Complexes with strong electron withdrawing substituents have longer lifetimes. The emission intensity of these complexes in DNA solution is comparible to the one in nonaqueous solution. Their lifetimes for Ru(bpy)2dppz2+, Ru(dcbpy)2dppz2+, Ru(Cl2bpy)2dppz2+, Ru(tmbpy)2dppz2+ and Ru(dmbpy) 2dppz2+ are 190, 558, 419, 122 and 216 ns in DNA solution. The transient absorption spectra of Ru(tmbpy)2dppz2+ and Ru(dmbpy)2dppz2+ show that the MLCT excited-state has an absorption near 580 nm, which is characteristic of reduced dppz absorption. This is the direct evidence of a dppz localized MLCT excited state.
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Hu, Rui-Lin, and 胡睿霖. "Design and Implementation of Switched-Capacitor DC-DC Converter for Light-load Processor." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/956gvy.
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碩士國立臺灣大學
電子工程學研究所
106
The advantages of Switched-Capacitor Voltage Regulator (SCVR) are the high conversion efficiency and the ability to be fully integrated without external components. Therefore, the SCVR is applicable to be integrated in IoT (Internet of Things) products. These products need different operating voltages, and their working loads vary. Thus, this thesis intends to propose a SCVR, which can be used in the processor under low-loading mode and provide high conversion efficiency. This thesis first analyzes the basic theory of how the SCVR works. Then, the design parameters related to power efficiency loss of basic 2:1 SCVR are discussed. In order to obtain the best efficiency result, this thesis tried to find out which parameter of the electronic components should be properly changed under different working loads of circuit, and looked into the pros and cons of the existing designs. Finally, to make the circuit function on a favorable operating point and remain highly efficient, the proposed solution is to modify the operating frequency by feedback control method. The SCVR presented by this thesis can effectively enhance the efficiency of processor under low-loading mode. When the working load change, the best operating point of circuit deviates. The proposed feedback control method can make circuit function on a better operating point. The proposed solution is verified by TSMC 0.18µm CMOS designs. The design concept can significantly improve the efficiency dropping caused by the load change.
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Ho, Chih-Wei, and 何致緯. "Unsupervised Anomaly Detection Using Light Switch Information in Smart Homes." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/23742771750933813790.
Full textAbstract:
碩士國立臺灣大學
電信工程學研究所
103
Anomaly detection in smart homes has become one of the most important issues recently with the emergence of Internet of Things(IoT). By analyzing the enormous amount of data collected via IoT, anomaly detection techniques are able to detect anomalous behavior such as unusual activities, unconsciousness, falling down, health vitals, unauthorized intrusion, etc. However, current anomaly detection in smart homes has two issues that are not well addressed. First, most of deployed sensors lead to problems such as privacy violation, uncomfortable wear experiences, and a huge amount of battery replacement. Second, most anomaly detection algorithms adopt supervised or semi-supervised approaches that require users to label data, which is a heavy load especially for the elderly. To solve these problems, an unsupervised anomaly detection algorithm using light switches is proposed. It is an adapted model-based anomaly detection algorithm that can reduce the effect of outliers in training data. By adding constrains to the evaluated mixture model and recursively estimating the decision boundaries, the found decision boundaries are more representative of the normal regions where normal data frequently appear. The false alarm rate can be reduced in a given miss detection rate. Our goal is to find events that occur at unusual time point or last for unusual length and indicate where they occurred and why they are anomalous. To evaluate the proposed algorithm, 11 light switches are installed in an apartment with 4 permanent residents. The data collection is conducted in real life with 24 hours non-stopped and last for over 7-months. The detected anomalous events are compared with the ground truth provided by the residents, and the result shows that 80% anomalous events are detected with 25% false alarm rate. Our method also performs better than the existing unsupervised anomaly detection algorithms while analyzing the events with the requirement of miss detection rate less than 20%.
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Zhang, Chao. "A Dual-Supply Buck Converter with Improved Light-Load Efficiency." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9521.
Full textAbstract:
Power consumption and device size have been placed at the primary concerns for battery-operated portable applications. Switching converters gain popularity in powering portable devices due to their high efficiency, compact sizes and high current delivery capability. However portable devices usually operate at light loads most of the time and are only required to deliver high current in very short periods, while conventional buck converter suffers from low efficiency at light load due to the switching losses that do not scale with load current. In this research, a novel technique for buck converter is proposed to reduce the switching loss by reducing the effective voltage supply at light load.
This buck converter, implemented in TSMC 0.18 micrometers CMOS technology, operates with a input voltage of 3.3V and generates an output voltage of 0.9V, delivers a load current from 1mA to 400mA, and achieves 54 percent ~ 91 percent power efficiency. It is designed to work with a constant switching frequency of 3MHz. Without sacrificing output frequency spectrum or output ripple, an efficiency improvement of up to 20 percent is obtained at light load.
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Wang, Shun-Yuan, and 王順源. "Improved Light-Load Efficiency for Switched Mode Buck Converter Using PWM Operated Power-Save Mode." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/34310412496615545112.
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Huang, Chi-Wei, and 黃祈瑋. "Experimental Study of 1x12 Optical Switch Base on LCoS Spatial Light Modulator." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/60228077828758086374.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
103
In this research, an experimental study of 1x12 optical fiber switching system using Liquid Crystal on Silicon (LCoS) device based Spatial Light Modulator (SLM) is presented. The design, simulation and performance optimization of a 1x12 optical fiber switching system was performed through a ZEMAX optical simulation tool. The optical fiber switching architecture based on single mode fiber to single mode fiber (SMF to SMF), single mode fiber to multimode fiber (SMF to MMF) and multimode mode fiber to multimode fiber (MMF to MMF) have investigated and compared. From the simulation design, a 1x12 optical fiber switching system was experimentally implemented. The channel selection of the implemented optical fiber switching system based on LCoS device was designed as well as its fundamental properties was also measured. A digital transmission test at a speed of 1.25Gbps was applied to evaluate the system performance. From the measurement results, it has shown that optical fiber switching system based on SMF to MMF switching architecture has a better fiber coupling efficiency than any other two fiber switching architecture. The analysis of system light loss has also shown that LCoS device using multilevel phase modulation to perform the channel selection can reduce the system light loss of around 5~6 dB compared with using binary phase modulation. In the digital transmission test, the 1x12 optical fiber switching system was evaluated at MMF to MMF switching architecture, and according to the measured eye diagrams, the estimated bit error ratio (BER) were all less than 10-10.
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Hsuan-JuChen and 陳玄儒. "A Three-Switch Single-Inductor Dual-Input Buck/Boost Converter for Light Energy Harvesting." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/99179920867488574710.
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碩士國立成功大學
電機工程學系
103
The design and analysis of energy harvesting (EH) for consumer electronics such as wireless sensor networks (WSNs) is presented in this thesis. The system can be powered by ambient energy in conjunction with rechargeable batteries to achieve near-perpetual operation. One common solution is to harvest energy from ambient light through photovoltaic (PV) modules. In such a system, a battery acts as the backup source to supplement energy when the environment’s power provision is insufficient or when the WSN is active, and stores surplus energy for future use when the WSN is inactive. Accordingly, power management in an EH system involves a balance among the PV module, battery and load. Compared to traditional methods which use two stage dc-dc converter or multi-input multi-output topology, an energy-recycling concept is proposed and the corresponding converter is implemented in this thesis. It uses fewer switches to balance the power among three elements. Additionally, the sizes of switches are optimized for reducing power losses. Consequently, compared with state-of-the-arts, both the power loss and chip area can be simultaneously reduced. Finally, the corresponding voltage regulator with maximum power point tracking are also proposed in this thesis. The proposed EH integrated circuit (IC) is fabricated with TSMC 0.35μm 2P4M 3.3V/5V Mixed-Signal CMOS process. The total chip area is 0.79mm2, and the active area is 0.5mm2 which is at least less than 30% compared to state-of-the-arts. Measured result shows that this IC features 93% peak conversion efficiency, which is 12% higher compared to state-of-the-arts. Moreover, this work also has higher efficiency over the entire load power range than current state-of-the-arts to meet the power- and volume-efficient requirements of WSNs.
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Dawes, Andrew M. C. "Using Transverse Optical Patterns for Ultra-Low-Light All-Optical Switching." Diss., 2008. http://hdl.handle.net/10161/604.
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Chang, Yu-Liang, and 張宇良. "A Single Stage Single Switch Flyback-Forward Converter with PFC and LED Light Source System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/11130797811002469003.
Full textAbstract:
碩士國立高雄應用科技大學
電機工程系博碩士班
101
This paper proposes a single-stage single-switch Flyback-Forward converter as a LED driver lighting circuit. This structure is an improvement of a typical flyback converter, when the switch is turned on, the energy can be outputted, when the switch is turned off, also energy can be inputted. This structure can improve the typical flyback converter that is only designed for low-to-medium power. Therefore, the output power is up to 150W-200W. Besides, a boost inductor is added in the input of the converter, to make it has the function of power factor correction. This paper will also explore the circuit analysis and design. In order to improve the efficiency of the converter, design a control loop to make the switch zero-current-switching, to reduce switching losses. And design a transformer leakage inductance energy recovery circuit, when the switch turns off, the spike and surge oscillation can be reduced, the leakage inductance energy is stored in the clamp capacitance, so the switch voltage can be reduced. At the next switch turn-on, the energy in the clamp capacitor is recovered to the bulk capacitor. Finally, the converter is verified using IsSpice software and a prototype 150W (36V/4.2A) AC / DC LED driver and lighting circuits are implemented. Use the valley switching and the leakage inductance energy recovery circuit, there is no spike when switching, and the overall efficiency is up to 90%, higher than the efficiency of 85% in the industry. Also it has the function of the power factor correction.
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Chou, Kao-Hsu, and 周高旭. "An Optical Switch of Natural Light Guiding System Based on Cubic Structure with Fresnel Surface." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/87271138008837104096.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
98
Recently, many researches focus on the sunlight illumination to provide for indoor lighting and saving energy which is called Nature Light Guiding System. For indoor lighting, it can provide the same brightness as the tradition lamp and it can also save 80% energy with the lamp. In order to use the sunlight effectively, we design an optical to control and change the direction of the transmitted light. For the past optical switch, the efficiency is unable to achieve the desired result. To solve this problem, we use two lenses to redesign an optical switch and the parameters are calculated by the Q-U method.
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Hsueh, Yen Hsien, and 薛彥賢. "Factors that Cause New Product Failures in a SME: A Case Study of Multifunction Light Switch." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107CGU05627019%22.&searchmode=basic.
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shih, Ghien-an, and 施建安. "Current Stability of Active Matrix Heterostructure Field-Effect Transistors Switch Circuits Integrated with GaN Light Emitting Diode." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/17503803883087526958.
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碩士國立臺灣大學
光電工程學研究所
94
We demonstrate a novel GaN-based heterojunction field effect transistor (HFET) active matrix circuit for an LED ( Light emitting diode ) micro-display. Simulation results are shown with basic and improved circuits. Variations of process and material growth conditions are discussed by correlating device parameters with LED flow currents in this circuit. It shows that the HFET-LED control circuit approach provides a stability path to mitigate variations of LED currents during operations.
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Liu, Weiyang. "Instrumentation for Interstitial Photodynamic Therapy of Prostatic Carcinoma." Master's thesis, 2010. http://hdl.handle.net/10048/942.
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This thesis encompasses the development and testing of an interstitial photodynamic therapy (iPDT) system for the treatment of prostate cancer. It begins with the optical characterization of a novel photosensitizer (SL-052) followed by a study of tissue optics as it applies to iPDT. The design and integration of a time-fractionated light delivery system with real-time spectral detection is then examined. An optical phantom test medium is formulated and in vitro system operation and testing is performed. Finally, in vivo experiments are performed on animal models with a focus on canine prostate iPDT. Unique optical results with dosimetric relevance are discovered and investigated. This includes metrics for optically measuring local in vivo SL-052 concentrations in real-time as well as novel oscillatory drug photobleaching and recovery behavior during time-fractionated light delivery.Photonics and Plasmas
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Chen, Po-Ting, and 陳柏廷. "I.Using Signal Processing to Improve the Accuracy of Peak Width Obtained by Right-Angle Light- Scattering and Develop a Method to Calculate the Molecular Weight at Low Signal-to-Noise RatioII. Integrating Electrowetting on Dielectrics Device as Flow Switch with Micro-flow Cytometer." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/46237669193725618735.
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碩士國立中正大學
化學暨生物化學研究所
103
Abstract I. Static light-scattering (LS) detection can determine the molecular weight (Mw) of polymers eluted with size-exclusion chromatography (SEC) without using any standards when the differential refraction index (RI) of solutes are obtained. On the other hand, the noisy chromatographic signal peak acquired using a static LS detector often causes difficulty in peak-width recognition. This disadvantage limits the determination accuracy and precision of the values. This study developed one second-order derivative filtering procedure by convolving the original LS chromatogram against the second-derivative curve of one artificial Gaussian-shape chromatographic peak to suppress the noises and to correct the baseline of the chromatogram. More accurate estimations of the chromatographic peak widths of pullulan samples were achieved to improve the determination accuracy. For noisy original chromatography peaks of pullulan 5 k (SNR of approximately 10), the non-ideal determination accuracy of the values (9.3%) is improved to –1.3% with the assistance of the filtering procedures. In addition, when the signal to noise ratio of the polymer sample is lower than the calculated limitation of the built-in application software package OmniSEC 4.6 (SNR lower than 10), the weight-average molecular weight (Mw) can not be calculated. But the has occupied a very important role in the synthesis of polymers. To overcome this limitation, we consider the principles of refractometer and light-scattering detector to get the molecular weight. Using the filtering procedure we designed in part one to find the more accurate peak width, then combining the numerical calculation to calculate the molecular weight of low SNR signal. We infer that we can use the numerical calculation to get the molecular weight measured from the SEC which the SNR is lower than the limitation of the software package. This method increased the calculable SNR of the software package OmniSEC to calculate the polymers’ weight-average molecular weight. Abstract II. Electrowetting on dielectrics (EWOD) is droplet-based microfluidic technique to control the generation, division, merge, or movement of droplets via electrical signals. The mechanical parts such as pumps and valves are not in needed for electrically actuated EWOD device. In this study, the dual-planar ITO glass slides were used to fabricate EWOD chip. The standard photolithography techniques were utilized to craft the bottom planar electrode array to coat with photoresist dielectric layer. The upper ITO glass slide was drilled through and chamfered for the convenience to fill liquid droplet. In addition, the dual-planar ITO glass slides were coated with the Teflon hydrophobic layer of 300 nm in thickness. The applied electric field with voltage 70 Vpp of 1 kHz is switched by relays to trigger the electrode on the bottom slide consecutively. This design of semi-opened chip can directly receive liquid sample or connect with the micro-channel outlet of continuous flow. In the future, we want to use the photomultiplier to pick up the signals from the fluorescence particles and couple with this EWOD microchip to separate the fluorescence particles from other non- fluorescence particles.