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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

Potentialités de la technologie CMOS 65nm SOI pour des applications sans fils en bande millimétrique

Martineau, Baudouin 16 May 2008 (has links) (PDF)
Dans le cadre des nouvelles applications dans la bande de fréquence millimétrique, une évaluation de la technologie CMOS 65nm SOI pour la conception de circuits est proposée. Cette évaluation s'articule autour de deux axes principaux. Tout d'abord les composants actifs et passifs spécifiques à la technologie font l'objet d'une étude en terme de performances et de modélisations. Ensuite la technologie est évaluée au travers l'exemple de circuits composant une chaîne de réception
242

Integrated RF modules and passives on low-cost flexible materials for applications up to the mm-wave frequency range

Rida, Amin Hassan 04 April 2011 (has links)
The objective of the proposed research is to develop solutions for High-Performance Low-Cost Passives for Radar, Identification, and Communication Applications up to mm-Wave Frequencies. This research will bring to the table potential solutions that will meet three main requirements: small size (or low weight), high performance, and low cost. This research embarks on antenna design and development for passive RFID tags on LCP substrates, and then a transition towards lower cost modules investigates and explores the possibilities of using paper as RF substrates with inkjet printing as a low cost fabrication technology. Modules such as dual band antenna for Wifi frequencies (2.4 GHz and 5 GHz) and UWB (up to 10GHz) on paper substrate using inkjet printing are presented. This work then bridges into developing higher frequency modules. These include: highly selective filter design on LCP for X-band Radar application to be used as a benchmark for an easy adjustment for higher frequencies, and antenna modules LCP using inkjet printing for communication such as mm-Wave WLAN or WPAN. A transition into mm-Wave Modules then takes place for the general realization of low-cost high-performance mm-Wave modules and more specifically the low cost automotive radar. After proposing an architecture for integrated mm-Wave module, this work then investigates 2D/3D interconnections (and their integration with antennas) on LCP using conventional etching design guidelines up to 100GHz. Antenna arrays that are implemented with phase shifters for beam steering are then designed using edge fed and multilayer technology. Furthermore, crosstalk reductions for highly dense transmission lines are analyzed via simulations for the optimum performance and space saving of such mm-Wave modules such as the IC interface where space restrictions are strictly enforced.
243

Simulations Numériques de Transferts Interdépendants d'Electrons et de Protons dans les Protéines

Gillet, Natacha 21 July 2014 (has links) (PDF)
Les processus d'oxydo-réduction impliquant des molécules organiques se retrouvent très fréquemment dans les protéines. Ces réactions comprennent généralement des transferts d'électrons et de protons qui se traduisent dans le bilan réactionnel par des transferts couplés proton-électron, des transferts simples d'hydrogène, d'hydrure... Une des principales méthodes pour élucider ces mécanismes est fournie par l'évaluation de grandeurs thermodynamiques et cinétiques. Expérimentalement, ces informations sont cependant obtenues avec une résolution temporelle souvent limitée à la milli/microseconde. Les simulations numériques présentées ici complètent, à des échelles de temps plus courtes (femto, pico, nanosecondes), ces données expérimentales. Il existe de nombreuses méthodes de simulations dédiées à l'étude de mécanismes redox dans les protéines combinant la description quantique des réactifs (QM) nécessaire à l'étude des changements d'états électroniques et la description classique de l'environnement (MM), l'échantillonnage de conformations se faisant grâce à des simulations de dynamique moléculaire (MD). Ces méthodes diffèrent par la qualité de la description du mécanisme réactionnel et le coût en temps de calcul. L'objectif de cette thèse est d'étudier les mécanismes de différents processus impliquant des transferts de protons et d'électrons en recherchant à chaque fois les outils adaptés. Elle comporte trois parties : i) l'évaluation de potentiels redox de cofacteurs quinones ; ii) la description du mécanisme d'oxydation du L-lactate dans l'enzyme flavocytochrome b2 ; iii) la décomposition d'un transfert formel d'hydrure entre deux flavines au sein de la protéine EmoB. Dans le cas du calcul des potentiels redox, nous utilisons une méthode notée QM+MM où la description électronique se fait en phase gaz au niveau DFT tandis que les simulations de MD s'effectuent classiquement. Nous appliquons l'approximation de réponse linéaire (ARL) pour décrire la réponse du système aux étapes de changement d'état de protonation ou d'oxydation de la fonction quinone ce qui aboutit au calcul du potentiel redox théorique. Nous avons ainsi pu établir une courbe de calibration des résultats théoriques en fonction des données expérimentales, confirmant la validité de l'ARL pour les cofacteurs quinones dans l'eau. La méthode a été étendue à la protéine MADH mais les limites de l'ARL ont été atteintes du fait des fluctuations importantes de l'environnement. L'étude de l'oxydation du L-lactate en pyruvate repose sur le calcul de surfaces d'énergie libre au niveau AM1/MM. Ces surfaces sont obtenues à l'aide de simulations de MD biaisées puis corrigées à l'aide de calculs d'énergies DFT. Différents chemins de réactions impliquant les transferts d'un proton et d'un hydrure du substrat vers une histidine et une flavine respectivement ont pu être identifiés. Ces transferts peuvent être séquentiels ou concertés suivant la conformation du site actif ou les mutations effectuées. Les surfaces concordent avec les effets observés expérimentalement. Les barrières obtenues restent cependant supérieures à celles attendues ouvrant la voie à d'autres simulations. La décomposition du mécanisme de transfert d'hydrure en transfert d'électron et d'atome d'hydrogène s'appuie sur de longues simulations classiques et des calculs d'énergies au niveau DFT contrainte (cDFT)/MM. La DFT contrainte permet de décrire les états diabatiques associés au transfert d'électron à différents stades du transfert d'hydrogène. En appliquant l'ARL, nous pouvons construire des paraboles correspondant aux états diabatiques et déterminer la séquence des évènements de transfert d'électron et d'hydrogène. La comparaison entre milieux protéique et aqueux nous a permis d'établir que le rôle de la protéine dans le transfert d'hydrure global est de bloquer le transfert d'électron en l'absence du transfert d'hydrogène empêchant ainsi la formation de flavines semi-réduites.
244

Vertical integration of inkjet-printed RF circuits and systems (VIPRE) for wireless sensing and inter/intra-chip communication applications

Cook, Benjamin Stassen 22 May 2014 (has links)
Inkjet-printing is a technology which has for the last decade been exploited to fabricate flexible RF components such as antennas and planar circuit elements. However, the limitations of feature size and single layer fabrication prevented the demonstration of compact, and high efficiency RF components operating above 10 GHz into the mm-Wave regime which is critical to silicon integration and fully-printed modules. To overcome these limitations, a novel vertically-integrated fully inkjet-printed process has been developed and characterized up to the mm-Wave regime which incorporates up to five highly conductive metal layers, variable thickness dielectric layers ranging from 200 nm to 200 um, and low resistance through-layer via interconnects. This vertically-integrated inkjet printed electronics process, tagged VIPRE, is a first of its kind, and is utilized to demonstrate fully additive RF capacitors, inductors, antennas, and RF sensors operating up to 40 GHz. In this work, the first-ever fully inkjet printed multi-layer RF devices operating up to 40 GHz with high-performance are demonstrated, along with a demonstration of the processing techniques which have enabled the printing of multi-layer RF structures with multiple metal layers, and dielectric layers which are orders of magnitude thicker than previoulsy demonstrated inkjet-printed structures. The results of this work show the new possibilities in utilizing inkjet printing for the post-processing of high-efficiency RF inductors, capacitors, and antennas and antenna arrays on top of silicon to reduce chip area requirements, and for the production of entirely printed wireless modules.
245

Vibrational Properties of Quinones in Photosynthetic Reaction Centers

Zhao, Nan 12 August 2014 (has links)
Fourier transform infrared difference spectroscopy (FTIR DS) is widely used to study the structural details of electron transfer cofactors in photosynthetic protein complexes. In photosynthetic proteins quinones play an important role, functioning as a cofactor in light-driven electron transfer. In photosystem I (PS I) phylloquinone (PhQ) functions as an intermediary in electron transfer. To investigate the properties of PhQ that occupies the, so called, A1 binding site in PS I, time-resolved step-scan FTIR DS, with 5µs time resolution at 77K has been used. By replacing PhQ in the A1 binding site with specifically isotope labeled version, information on the vibrational frequencies associated specifically with the quinone in the binding site were obtained, which could be compared to the vibrational properties of quinone in solution or quinones in other protein binding sites. To further aid in assessing the origin of bands in the spectra, quantum mechanics /molecular mechanics (QM/MM) ONIOM type calculations were undertaken. ONIOM is an acronym for Our own N-layered Integrated molecular Orbital and molecular Mechanics. We find that the phytyl tail of PhQ does not play an important role in the orientation of PhQ in the A1 binding site. We also find that PhQ, in both neutral and reduced states, is strongly hydrogen bonded. To test and verify the applicability of our QM/MM approach, ONIOM calculations were also undertaken for ubiquinone and a variety of other quinones incorporated into the, so called, QA binding site in purple bacteria photosynthetic reaction centers. The calculated and experimental spectra agree well, demonstrating the utility and applicability of our ONIOM approach. Hydrogen bonding to the carbonyl groups of quinones in the QA binding site was shown to be relatively weak, and it was found that hydrogen bonding to neutral ubiquinone in purple bacterial reaction centers can be considered in purely electrostatic terms, contrary to the widely held belief that the hydrogen bonding amino acids should be treated quantum mechanically.
246

Circuit and System Design for mm-wave Radar and Radio Applications

Sarkas, Ioannis 13 August 2013 (has links)
Recent advancements in silicon technology have paved the way for the development of integrated transceivers operating well inside the mm-wave frequency range (30 - 300 GHz). This band offers opportunities for new applications such as remote sensing, short range radar, active imaging and multi-Gb/s radios. This thesis presents new ideas at the circuit and system level for a variety of such applications, up to 145 GHz and in both state-of-the-art nanoscale CMOS and SiGe BiCMOS technologies. After reviewing the theory of operation behind linear and power amplifiers, a purely digital, scalable solution for power amplification that takes advantage of the significant ft/fmax improvement in pFETs as a result of strain engineering in nanoscale CMOS is presented. The proposed Class-D power amplifier, features a stacked, cascode CMOS inverter output stage, which facilitates high voltage operation while employing only thin-oxide devices in a 45 nm SOI CMOS process. Next, a single-chip, 70-80 GHz wireless transceiver for last-mile point-to-point links is described. The transceiver was fabricated in a 130 nm SiGe BiCMOS technology and can operate at data rates in excess of 18 Gbps. The high bitrate is accomplished by taking advantage of the ample bandwidth available at the W-band frequency range, as well as by employing a direct QPSK modulator, which eliminates the need for separate upconversion and power amplification. Lastly, the system and circuit level implementation of a mm-wave precision distance and velocity sensor at 122 and 145 GHz is presented. Both systems feature a heterodyne architecture to mitigate the receiver 1/f noise, as well as self-test and calibration capabilities along with simple packaging techniques to reduce the overall system cost.
247

Circuit and System Design for mm-wave Radar and Radio Applications

Sarkas, Ioannis 13 August 2013 (has links)
Recent advancements in silicon technology have paved the way for the development of integrated transceivers operating well inside the mm-wave frequency range (30 - 300 GHz). This band offers opportunities for new applications such as remote sensing, short range radar, active imaging and multi-Gb/s radios. This thesis presents new ideas at the circuit and system level for a variety of such applications, up to 145 GHz and in both state-of-the-art nanoscale CMOS and SiGe BiCMOS technologies. After reviewing the theory of operation behind linear and power amplifiers, a purely digital, scalable solution for power amplification that takes advantage of the significant ft/fmax improvement in pFETs as a result of strain engineering in nanoscale CMOS is presented. The proposed Class-D power amplifier, features a stacked, cascode CMOS inverter output stage, which facilitates high voltage operation while employing only thin-oxide devices in a 45 nm SOI CMOS process. Next, a single-chip, 70-80 GHz wireless transceiver for last-mile point-to-point links is described. The transceiver was fabricated in a 130 nm SiGe BiCMOS technology and can operate at data rates in excess of 18 Gbps. The high bitrate is accomplished by taking advantage of the ample bandwidth available at the W-band frequency range, as well as by employing a direct QPSK modulator, which eliminates the need for separate upconversion and power amplification. Lastly, the system and circuit level implementation of a mm-wave precision distance and velocity sensor at 122 and 145 GHz is presented. Both systems feature a heterodyne architecture to mitigate the receiver 1/f noise, as well as self-test and calibration capabilities along with simple packaging techniques to reduce the overall system cost.
248

Design and Development of 75 mm Fixed-Wing Nano Air Vehicle

Pushpangathan, Jinraj V January 2017 (has links) (PDF)
This thesis deals with the design and development of a 75 mm fixed-wing nano-air vehicle (NAV). The NAV is designed to fit inside a cube with each side measuring 75 mm. The range and endurance of the NAV are 300 m and 2-3 minutes, respectively. The high-wing horizontal tailless NAV has a take-off weight of 19.5 g. The battery-powered single propeller NAV has two control surfaces in the form of elevator and rudder. This thesis contains a detailed account of the airfoil selection, selection of the configuration of NAV and the longitudinal, lateral and directional aerodynamic characterization of the NAV. The development of one of the lightweight autopilot hardware which weighs 1.8 g is also given in detail. The development of non-linear equations of motion of NAV including thrust and coupling effects is also discussed. The effects of the gyroscopic coupling and counter torque on the linear dynamics of the NAV are analyzed by conducting a parametric study about the variation of the eigenstructure attributable to the varying degree of coupling in the system matrix of the linear coupled model. A robust simultaneously stabilizing output feedback controller is synthesized for stabilizing the plants of the NAV. The synthesizing of the robust simultaneously stabilizing output feedback controller is based on a frequency-shaped central plant. A new procedure is developed to determine the frequency-shaped central plant utilizing the v-gap metric between the plants, the frequency-shaping of the plants with the pre and post compensators and the robust stabilization theory. An optimization problem is formulated to obtain these compensators. A novel iterative algorithm is developed to acquire the compensators by solving the optimization problem. Thereafter, an iterative algorithm is developed to find an output feedback controller for robust simultaneous stabilization by blending the existing features of robust stability condition of right co-prime uncertainty model of the frequency-shaped central plant, the maximum v-gap metric of the frequency-shaped central plant, H∞ loop-shaping and eigenstructure assignment algorithm for output feedback using the genetic algorithm. The six-degree-of-freedom numerical and hardware-in-loop simulations (HILS) of closed-loop non-linear and linear plants of NAV are performed to assess the performance of the controller and to validate the control algorithm implemented in the autopilot. The airworthiness of the aircraft is tested by conducting flight trials in radio-controlled (RC) mode without including the autopilot. The successful RC flight trial of the NAV indicates airworthiness of the aircraft which aided in freezing the configuration. This is one of the smallest fixed wing aerial vehicle that was successfully flown till date.
249

QM/MM simulations of electronic transport properties for DNA sensing devices based on graphene / Simulações QM/MM das propriedades de transporte eletrônico para dispositivos de sensoriamento de DNA baseados em grafeno

Martins, Ernane de Freitas 04 June 2018 (has links)
Submitted by ERNANE DE FREITAS MARTINS (ernanefmg@hotmail.com) on 2018-06-21T18:31:22Z No. of bitstreams: 1 Tese_Ernane_FINAL.pdf: 73762259 bytes, checksum: 783c569159077630257fc1df333452da (MD5) / Approved for entry into archive by Hellen Sayuri Sato null (hellen@ift.unesp.br) on 2018-06-22T17:57:30Z (GMT) No. of bitstreams: 1 martins_ef_dr_ift.pdf: 73762259 bytes, checksum: 783c569159077630257fc1df333452da (MD5) / Made available in DSpace on 2018-06-22T17:57:30Z (GMT). No. of bitstreams: 1 martins_ef_dr_ift.pdf: 73762259 bytes, checksum: 783c569159077630257fc1df333452da (MD5) Previous issue date: 2018-06-04 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Nanotechnology is an important and very active area of research contributing to many different fields. The development of new devices applied to personalized medicine is one of its applications. When we desire to develop new devices many effort are done, including experimental and theoretical investigations. The theoretical/computational physics can enormously contribute to this area, since the simulations can reveal the working mechanism in these systems being possible to understand and propose new devices with improved performance. We present an extensive theoretical investigation of the electronic transport properties of graphene-based devices for DNA sensing. We have used a hybrid methodology which combines quantum mechanics and molecular mechanics, the so called QM/MM method, coupled to electronic transport calculations using non-equilibrium Green’s functions. First, we studied graphene in solution in order to understand the effects of polarization on the electronic and transport properties under different salt concentrations. We also stud- ied graphene with Stone-Wales defect in pure water. For these systems we tested a simple polarization model based on rigid rods. Our analysis were also done over different QM/MM partitions including explicit water molecules in the quantum part. Our results showed that the inclusion of the solvent in the electronic transport calculations for graphene decreases the total transmission, showing the important role played by the water. Our results also showed that the electronic transport properties of graphene do not suffer significant changes as we increase the salt concentration in the solution. The inclusion of polarization effects in graphene, despite changing the structuring of water molecules that make up the first solvation shell of graphene, do not significantly affect the electronic transport through graphene. We then studied DNA sequencing devices. First we focused on sequencing using a nanopore between topological line defects in graphene. Our results showed that sequencing DNA with high selectivity and sensitivity using these devices appears possible. We also address nanogap in graphene. For this we looked at the effects of water on electronic transport by using different setups for the QM/MM partition. We showed that the inclusion of water molecules in the quantum part increases the electronic transmission in several orders of magnitude, also showing the fundamental role played by water in tunneling devices. The electronic transport simulations showed that the proposed device has the potential to be used in DNA sequencing, presenting high selectivity and sensitivity. We propose an graphene-based biochip for sequence-specific detection of DNA strands. The main idea of this sort of device is to detect hybridization of single-stranded DNA, forming double-stranded DNA. We showed that the vertical DNA adsorption, either through an anchor molecule (pyrene) or using the nucleotide itself as anchor, do not present good results for detection, since the signals for the single and double strands are quite similar. For the case of horizontal DNA adsorption on graphene our results indicated that the two signals can be distinguishable, showing promising potential for sensitivity and selectivity. / Nanotecnologia é uma importante e muito ativa área de pesquisa contribuindo para muitos campos diferentes. O desenvolvimento de novos dispositivos aplicados à medicina personalizada é uma de suas aplicações. Quando desejamos desenvolver novos dispositivos muitos esforços são feitos, incluindo investigações experimentais e teóricas. A Física teórica/computacional pode contribuir enormemente com esta área, já que simulações podem revelar o mecanismo de funcionamento nesses sistemas tornando possível entender e propor novos dispositivos com desempenho melhorado. Nós apresentamos uma extensa investigação teórica das propriedades de transporte eletrônico de dispositivos baseados em grafeno para sensoriamento de DNA. Utilizamos uma metodologia híbrida que combina mecânica quântica e mecânica molecular, o chamado método QM/MM, acoplado a cálculos de transporte eletrônico utilizando funções de Green fora do equilíbrio. Primeiramente nós estudamos grafeno em solução de modo a entender os efeitos de polarização nas propriedades eletrônica e de transporte em diferentes concentrações de sal. Também estudamos grafeno com defeito Stone-Wales em água pura. Para esses sistemas, testamos um modelo de polarização simples baseado em bastões rígidos. Nossas análises também foram feitas em diferentes partições QM/MM incluindo moléculas de água explícitas na parte quântica. Nossos resultados mostraram que a inclusão do solvente nos cálculos de transporte eletrônico para o grafeno diminui a transmissão total, mostrando o papel fundamento desempenhado pelo água. Nossos resultados também mostraram que as propriedades de transporte eletrônico do grafeno não sofrem mudanças significativas na medida em que aumentamos a concentração de sal na solução. A inclusão de efeitos de polarização em grafeno, apesar de mudar a estruturação das moléculas de água que compõem a primeira camada de solvatação do grafeno, não afeta significativamente o transporte eletrônico através do grafeno. Nós, então, estudamos dispositivos para sequenciamento de DNA. Focamos primeira- mente no sequenciamento usando nanoporo entre defeitos de linha topológicos no grafeno. Nossos resultados mostraram que o sequenciamento de DNA com alta seletividade e sensitividade usando esses dispositivos se mostra possível. Nós também abordamos nanogap em grafeno. Para tal, avaliamos os efeitos da água no transporte eletrônico utilizando diferentes configurações para a partição QM/MM. Mostramos que a inclusão de moléculas de água na parte quântica aumenta a transmissão eletrônica em várias ordens de grandeza, também mostrando o papel fundamental desempenhado pela água em dispositivos de tunelamento. As simulações de transporte eletrônico mostraram que o dispositivo proposto tem o potencial de ser usado em sequenciamento de DNA, apresentando alta seletividade e sensitividade. Propusemos um biochip baseado em grafeno para detecção de sequências específicas de fitas de DNA. A ideia principal desta classe de dispositivos é detectar a hibridização da fita simples de DNA, formando a fita dupla de DNA. Mostramos que a adsorção vertical de DNA, seja utilizando uma molécula âncora (pireno) ou utilizando o próprio nucleotídio como âncora, não apresenta bons resultados para detecção, já que os sinais para as fitas simples e dupla são bem próximos. Para o caso da adsorção horizontal de DNA em grafeno nossos resultados indicaram que os dois sinais podem ser distinguíveis, mostrando potencial promissor para sensitividade e seletividade.
250

Messagingová infrastruktura a produktová analýza trhu / Message infrastructure and market analysis

Klimeš, Ivo January 2008 (has links)
There are considered modern messaging architectonical concepts SOA and EDA in this diploma thesis. There are presented the elementary principals of functioning of these paradigms and principals are given into the wider context with the business processes and IT Governance. The aim of this thesis is to compare two preselected software solutions of the operational monitoring. There is always one solution per architectonical style and predefined comparative criteria. This thesis is divided into five consequential parts. The first part is focused on the putting the modern architectures into the historical context. The historical context is the way out for the modern architectonical styles. The part afterwards is closely focused on the concepts of SOA and EDA, and also on the comparison of the mentioned architectonical styles. There are put the concepts into the connection with business processes and maturity models In the next chapters. That all together has a influence on the successful implementation and governance. The chapters continuously flow into the last theoretical part of the thesis, IT Governance. There are described all the elements connected with the successful IT systems operating based on the paradigm SOA or EDA. The context in the practical part is link to the all these previous chapters. There are selected and described two software solutions in the practical part of this thesis. These solutions are then compared by the predefined criteria. The conclusion summarizes all the knowledge acquired during the paradigm comparison and there are also summarized knowledge acquired during the comparison of selected monitoring products.

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