Thesis (Ph. D.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed March 18, 2009) Includes bibliographical references.

Dissertation (Ph.D.)--Auburn University, / Abstract. Vita. Includes bibliographic references (p.117-130).

Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 104-107). Also available on the World Wide Web.

Thesis (M.S.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed October 25, 2007) Includes bibliographical references (p. 61-62).

Βασικός σκοπός της εργασίας αυτής, είναι η μελέτη και σχεδίαση ενός κυκλώματος ανάγνωσης χωρητικού βιοαισθητήρα χρησιμοποιώντας τάση αναφοράς. Τα κυκλώματα αυτά αποτελούν βασικό τμήμα σε πολλά ολοκληρωμένα κυκλώματα, καθώς μπορούν να παρέχουν σταθερή τάση. Αρχικά εξετάζεται η αρχή λειτουργίας τους, και παρουσιάζοντα κάποιες βασικές τοπολογίες που εφαρμόσθηκαν σε CMOS τεχνολογίες. Καθώς οι τεχνολογικές εξελίξεις επιβάλλουν όσο το δυνατόν χαμηλότερη κατανάλωση και οικονομία σε επιφάνεια πυριτίου η σχεδίαση επιλέγεται να πραγματοποιηθεί σε γνωστή CMOS τεχνολογία 90nm, με την βοήθεια του εργαλείου Cadence. Σκοπός είναι από την τάση εξόδου του κυκλώματος να μπορει να βρεθεί η διαφορά της χωρητικότητας των πυκνωτών της εισόδου. Αυτή η τάση στη συνέχεια μπορεί να δοθεί για ψηφιακή επεξεργασία, αφού περάσει από έναν ADC.Η τροφοδοσία του κυκλώματος ήταν στα 2.5 Volts και στις εξομοιώσεις που παρατίθενται παρουσιάστηκαν ικανοποιητικά επίπεδα θορύβου στην συχνότητα 1kHZ. / The subject of this thesis is the study and analysis of a readout circuit with capacitive biosensor using voltage reference. Being able to provide a stable output voltage, these circuits are indispensable building block of many analog integrated circuits. The first and second chapters discuss the operating principle and some conventional bandgap circuits, which have been introduced in CMOS technologies. As the process technologies are developing and impose constraints, such as low-power consumption and downscaling the expense of silicon area, the design option was a popular CMOS 90 nm technology, with the aid of the software program Cadence. The purpose of the circuit studied is to find the input capacitors differences from the output voltage. This output voltage can then be paid for digital processing, after passing through an ADC. The power circuit was at 2.5 Volts and at the simulations presented satisfactory noise level at 1kHZ.

Orientador: Carlos César Bof Bufon / Banca: Elidiane Cipriano Rangel / Banca: Lucas Fugikawa Santos / Resumo: Conhecido como o ramo da ciência que utiliza camadas moleculares ativas para agregar novas funcionalidades a dispositivos, a eletrônica molecular apresenta propostas promissoras para o futuro. Uma classe de pequenas moléculas semicondutoras que vem sendo explorada devido ao seu potencial na fabricação de diferentes dispositivos é a das ftalocianinas de cobre (CuPc). Entretanto, poucos trabalhos presentes na literatura relatam a relação entre a características elétricas dos filmes orgânicos e sua espessura em nanoescala. Tal fato é explicado pela dificuldade na deposição de contatos elétricos sobre as camadas moleculares, dado que os métodos atualmente empregados podem vir a danificá-las. Nesse contexto, essa dissertação apresenta a fabricação de um capacitor hibrido ultracompacto (h-Cap) constituído por metal / óxido dielétrico / camada molecular / Metal como uma plataforma para acessar as propriedades elétricas de camadas moleculares. Utilizando como a camada metálica a combinação de filmes finos de ouro, titânio e cromo, óxido de alumínio (Al2O3) para o dielétrico e filmes finos de CuPc como camadas moleculares, os h-Caps são fabricados a partir da técnica roll-up. Para a deposição dos filmes metálicos foi utilizado a técnica de evaporação térmica por feixe de elétrons, a técnica de deposição por camada atômica foi utilizada para a deposição do Al2O3 e pôr fim a técnica de deposição por evaporação por filamento resistivo para as camadas moleculares de CuPc. As característic... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Known as the branch of science that uses active molecular layers to add new functionality to devices, molecular electronics presents promising proposals for the future. A class of small semiconductor molecules being exploited due to its potential in the manufacture of different devices is that of copper phthalocyanines (CuPc). However, few papers in the literature report the relationship between the electrical characteristics of organic films and their thickness at the nanoscale. This fact is explained by the difficulty in the deposition of electrical contacts on the molecular layers, since the methods currently used may damage them. In this context, this dissertation presents the fabrication of an ultracompact hybrid capacitor (h-Cap) consisting of metal / dielectric oxide / molecular layer / metal as a platform to access the electrical properties of molecular layers. Used as the metallic layer is the combination of thin films of gold, titanium and chromium, aluminum oxide for the dielectric and thin films of CuPc as molecular layers, the h-Cap are formed from the roll-up technique. For the deposition of the metallic films was used the thermal evaporation technique by electron beam, the technique of deposition by atomic layer was used for the deposition of Al2O3 and finally the technique of deposition by evaporation by resistive filament for the molecular layers of CuPc . The geometric characteristics of the h-Caps were obtained using optical and scanning electron microscope... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-11-10T11:09:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-04-26Bitstream added on 2014-11-10T11:57:56Z : No. of bitstreams: 1 000793224.pdf: 1886730 bytes, checksum: 7281d86dc8378949468610bdc6fa019c (MD5) / Neste trabalho é apresentado o desenvolvimento de um modelo de programação linear inteira mista e outro de programação cônica de segunda ordem inteira mista para resolver o problema de alocação de bancos de capacitores fixos e/ou chaveados ao longo dos alimentadores primários de sistemas de distribuição de energia elétrica radiais, com o propósito de melhorar o perfil da magnitude de tensão e minimizar os custos de perdas de energia e de investimento. Nos modelos propostos, o cálculo do ponto de operação em regime permanente de sistemas de distribuição radiais é modelado matematicamente usando expressões lineares e cônicas de segunda ordem. O uso dos modelos garante a convergência para a solução ótima usando ferramentas de otimização clássica existentes. Os sistemas testes de 70, 136, 202 e 400 nós são utilizados para mostrar a exatidão dos modelos matemáticos, como também a eficiência das técnicas de solução propostas para resolver o problema de alocação de bancos de capacitores em sistemas de distribuição radiais. / This work shows the development of a mixed integer linear programming model and a mixed integer second-order conic programming model to solve the allocation problem of fixed or switched capacitors banks in radial electrical distribution systems, with the aims to improve the voltage magnitude profile and minimize the energy losses and investment costs. In the proposed models, the steady-state operation point of the radial distribution system is modeled through linear and second-order conic expressions. The use of a mixed-integer linear programming model and a second-order conic programming model guarantee convergence to optimality using existing optimization software. The test systems of 70, 136, 202 and 400 nodes are used in order to show the accuracy of the mathematical models, as well as the efficiency of the proposed solution technique to solve the allocation problem of fixed or switched capacitors banks in a radial distribution system.

Supercapacitors have attracted great attention because of their high power density, long life cycle and high efficiency. They can be generally classified into two types: electrical double-layer capacitors (EDLCs) and pseudocapacitors. Compared with pseudocapacitors, EDLCs have a very fast charge/discharge rate, higher power density, higher coulombic efficiency and longer cycle life. Recently, in order to meet the requirements of portable and wearable electronics, supercapacitor development is moving towards flexible and stretchable solutions. This thesis presents the design, fabrication, performance testing and optimisation of flexible strip and fibre EDLCs. In this research, a sandwich structured strip EDLC was designed and manufactured. Experimental design was utilised to optimise the operation parameters of the EDLC in order to improve its capacity for energy storage. The flexibility of the strip EDLCs was studied extensively by mechanical tests under static and dynamic loading conditions, and the correlation between the electrochemical performance of the EDLCs and the mechanical testing process was investigated. Novel coaxial fibre EDLCs have also been studied and developed in this study. Fibre supercapacitors showed a good flexibility and weavability. The activated carbon produced by ball-milling method with optimum specific capacitance was mixed with commercial ink to produce active material to optimise the electrochemical performance of fibre EDLCs. The flexible EDLCs were applied into different appliances to demonstrate the stability of performance and the usability of EDLCs developed in this study. The electrical current and potential range can be altered by connecting multiple strip or fibre EDLCs in parallel or in series to meet the power and energy requirements. It has been proved that the flexible EDLCs developed have a great potential to be used as energy storage devices for smart electronics. This thesis makes original contributions to knowledge, including using an advanced test method to study the electrochemical performance of flexible supercapacitors under static and dynamic mechanical testing, investigation of the effect of key parameters in the manufacturing process on the performance of strip supercapacitors using experimental design method to optimise the supercapacitors’ performance, and optimisation of the performance of fibre supercapacitors by improving the structure and using a new active material with higher specific capacitance.

Orientador: Rubén Augusto Romero Lázaro / Banca: José Roberto Sanches Mantovani / Banca: Geraldo Roberto Martins da Costa / Resumo completo, clicar acesso eletrônico abaixo. / Mestre

[pt] Um dos meios utilizados par aumentar a capacidade de transmissão das linhas é a compensação de parte da reatância indutiva dessas linhas através de capacitores série. Entretanto compensação série causa o aparecimento de freqüências de ressonância subsíncrona no sistema. Tendo como principal objetivo neste trabalho apresentar um método para a análise da Ressonância Subsíncrona devida a auto-excitação, começa-se por fazer um breve estudo sobre o problema da Ressonância Subsíncrona em geral e apresenta- se alguns dos seus efeitos. Desenvolve-se em seguida o modelo de gerador proposto por Kilgore er al. Para estudos de Ressonância Subsíncrona e apresentam-se os modelos da rede e dos equivalentes utilizados. O método de análise utilizado neste trabalho é então apresentado assim como os programas de cálculo desenvolvidos. Por fim são apresentados os resultados obtidos com estes programas utilizando-se um Sistema Teste e comparam-se estes resultados com aqueles conhecidos de um sistema semelhante. / [en] One of the methods used to increase power transfer capability is the partial compensation of the inductive reactance of lines through the use of series capacitors. This compensation, however, gives rise to subsynchronours resonance frequencies to appear in the system. Having as main objective of this work to present a method for subsynchronours resonance analysis due to self- excitation, one starts by making a short study about the subsynchronours resonance problem in general and presents some of its effects. One develops then the generator model proposed by kilgore and al for subsynchronours Resonancec studies and presents the network and equivalent models utilied. The analysis method used in this work as well as the calculation programmes developed are then presented. Finally results obtained with these programmes using a Test System are presented and compared with those known from a similar system.