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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.
81

Contribution au développement d'un microsystème d'analyse, intégrant pré-concentration ionique par micro-électrodialyse et détection électrochimique sur diamant dopé au bore. / Contribution to the development of a micro-analyser, integrating a micro-electrodialyser for preconcentration and an electrochemical detector on boron-doped diamond.

Le, Thanh Son 31 May 2011 (has links)
Ce travail est une contribution à la conception d'un système portatif et intégré de type µTAS (micro-Total Analysis System) pour le traitement (préconcentration et simplification) de solution aqueuses contenant des métaux lourds et leur analyse en ligne. Pour la préconcentration amont, l'étude a porté sur la réalisation d'un micro-électrodialyseur manipulant des µL de solutions. L'optimisation des paramètres opératoires a permis d'augmenter d'un facteur 100 environ les concentrations d'analytes. Pour l'étage de détection aval, un système sur puce de type polarographique a été étudié. Le traditionnel mercure est remplacé par du diamant polycristallin dopé au bore (DDB) préparé par CVD micro-ondes. La quantification des métaux lourds par redissolution anodique sur ce matériau a été validée ainsi que les techniques de gravure compatibles avec la réalisation de microréseaux d'électrodes. / This work is a contribution to the conception of an integrated μTAS (micro-Total Analysis System) for treatment (preconcentration and simplification) of aqueous solutions containing heavy metals and their on-line analysis. For upstream preconcentration, a micro-electrodialyser handling µL of solutions was developped. The optimization of operating parameters permitted to reach an analyte pre-concentration factor of about 100. For the downstream detection step, an on-chip polarographic system, where mercury was replaced by boron doped diamond (BDD), was studied. BDD films were prepared by assited microwave plasma CVD. Quantification of heavy metals by anodic stripping on BDD was validated as well as the etching technique compatible with the realization of microarray electrodes.
82

Algorithms and simulators for coupled device/circuit simulation

Dudar, Taras 11 December 2002 (has links)
Algorithms and simulators comprised of SPICE3 as a circuit level simulator and two device simulators EOFLOW and PROPHET for accurate simulation of new types of devices are presented in this thesis. An integration of EOFLOW with SPICE3 creates a capability for efficient simulation of a system containing interconnected electroosmotic flow channels together with control electronics. Using this simulator, an accurate simulation of a complex interconnection of channels has been performed. In addition, various flow control schemes have been evaluated for their effectiveness. Coupling of PROPHET and SPTCE3 allows for the simulation of accurate semiconductor device models. This capability is necessary for critical RF and analog applications. The coupled SPICE3-HB-PROPHET simulator incorporates the harmonic balance algorithm for large-signal frequency domain analysis. Applications of this analysis are demonstrated in the noise coupling between devices sharing the same silicon substrate. / Graduation date: 2003
83

Microfabrication of Plasmonic Biosensors in CYTOP Integrating a Thin SiO2 Diffusion and Etch-barrier Layer

Hanif, Raza 18 April 2011 (has links)
A novel process for the fabrication of Long Range Surface Plasmon Polariton (LRSPP) waveguide based biosensors is presented herein. The structure of the biosensor is comprised of Au stripe waveguide devices embedded in thick CYTOP claddings with a SiO2 solvent diffusion barrier and etch-stop layer. The SiO2 layer is introduced to improve the end quality of Au waveguide structures, which previously deformed during the deposit of the upper cladding process and to limit the over-etching of CYTOP to create micro-fluidic channels. The E-beam evaporation method is adapted to deposit a thin SiO2 on the bottom cladding of CYTOP. A new micro-fluidic design pattern is introduced. Micro-fluidic channels were created on selective Au waveguides through O2 plasma etching. The presented data and figures are refractive index measurements of different materials, thickness measurements, microscope images, and AFM images. Optical power cutback measurements were performed on fully CYTOP-cladded symmetric LRSPP waveguides. The end-fire coupling method was used to excite LRSPP modes with cleaved polarization maintaining (PM) fibre. The measured mode power attenuation (MPA) was 6.7 dB/mm after using index-matched liquid at input and output fibre-waveguide interfaces. The results were compared with the theoretical calculations and simulations. Poor coupling efficiency and scattering due to the SiO2 are suspected for off-target measurements.
84

Microfabrication of Plasmonic Biosensors in CYTOP Integrating a Thin SiO2 Diffusion and Etch-barrier Layer

Hanif, Raza 18 April 2011 (has links)
A novel process for the fabrication of Long Range Surface Plasmon Polariton (LRSPP) waveguide based biosensors is presented herein. The structure of the biosensor is comprised of Au stripe waveguide devices embedded in thick CYTOP claddings with a SiO2 solvent diffusion barrier and etch-stop layer. The SiO2 layer is introduced to improve the end quality of Au waveguide structures, which previously deformed during the deposit of the upper cladding process and to limit the over-etching of CYTOP to create micro-fluidic channels. The E-beam evaporation method is adapted to deposit a thin SiO2 on the bottom cladding of CYTOP. A new micro-fluidic design pattern is introduced. Micro-fluidic channels were created on selective Au waveguides through O2 plasma etching. The presented data and figures are refractive index measurements of different materials, thickness measurements, microscope images, and AFM images. Optical power cutback measurements were performed on fully CYTOP-cladded symmetric LRSPP waveguides. The end-fire coupling method was used to excite LRSPP modes with cleaved polarization maintaining (PM) fibre. The measured mode power attenuation (MPA) was 6.7 dB/mm after using index-matched liquid at input and output fibre-waveguide interfaces. The results were compared with the theoretical calculations and simulations. Poor coupling efficiency and scattering due to the SiO2 are suspected for off-target measurements.
85

Entwicklung optischer Feldmessverfahren zur Charakterisierung mikrofluidischer Mischungsvorgänge / Development of optical 2d measuring methods for characterisation of microfluidic mixing processes

Roetmann, Karsten 28 March 2008 (has links)
No description available.
86

Microfabrication of Plasmonic Biosensors in CYTOP Integrating a Thin SiO2 Diffusion and Etch-barrier Layer

Hanif, Raza 18 April 2011 (has links)
A novel process for the fabrication of Long Range Surface Plasmon Polariton (LRSPP) waveguide based biosensors is presented herein. The structure of the biosensor is comprised of Au stripe waveguide devices embedded in thick CYTOP claddings with a SiO2 solvent diffusion barrier and etch-stop layer. The SiO2 layer is introduced to improve the end quality of Au waveguide structures, which previously deformed during the deposit of the upper cladding process and to limit the over-etching of CYTOP to create micro-fluidic channels. The E-beam evaporation method is adapted to deposit a thin SiO2 on the bottom cladding of CYTOP. A new micro-fluidic design pattern is introduced. Micro-fluidic channels were created on selective Au waveguides through O2 plasma etching. The presented data and figures are refractive index measurements of different materials, thickness measurements, microscope images, and AFM images. Optical power cutback measurements were performed on fully CYTOP-cladded symmetric LRSPP waveguides. The end-fire coupling method was used to excite LRSPP modes with cleaved polarization maintaining (PM) fibre. The measured mode power attenuation (MPA) was 6.7 dB/mm after using index-matched liquid at input and output fibre-waveguide interfaces. The results were compared with the theoretical calculations and simulations. Poor coupling efficiency and scattering due to the SiO2 are suspected for off-target measurements.
87

An electromagnetically actuated rotary gate microvalve with bistability

Luharuka, Rajesh 03 January 2007 (has links)
Two types of rotary gate microvalves are developed for flow modulation in a microfluidic system that operates at high flow rate and/or uses particulate flow. This research work encompasses design, microfabrication, and experimental evaluation of these microvalves in three distinct areas compliant micromechanism, microfluidics, and electromagnetic actuation. The microvalve consists of a suspended gate that rotates in the plane of the chip to regulate flow through the orifices. The gate is suspended by a novel fully-compliant in-plane rotary bistable micromechanism (IPRBM) that advantageously constraints the gate in all other degrees of freedom. Multiple inlet/outlet orifices provide flexibility of operating the microvalve in three different flow/port configurations. The suspended gate is made of a soft magnetic material and is electromagnetically actuated like a rotor in a variable-reluctance stepper motor. Therefore, an external electromagnetic (EM) actuation at the integrated set of posts (stator) causes the gate mass to switch from its default angular position to a second angular position. The microvalve chip is fabricated by electroplating a soft magnetic material, Permalloy (Ni80Fe20) in a sacrificial photoresist mold on a Silicon substrate. The inlet/outlet orifices are then etched into the Silicon substrate from the back-side using deep-reactive ion etch process. Finally, the gate structure is released by stripping the PR and seed layers. This research work presents the realization of a new microvalve design that is distinct from traditional diaphragm-type microvalves. The test results are encouraging and show the potential of these microvalves in effectively modulating flow in microfluidic systems that may not require a tight seal. The microvalve uses a novel in-plane rotary bistable micromechanism that may have other applications such as optical shutters, micro-locks, and passive check valves.
88

Dual-axis fluidic thrust vectoring of high-aspect ratio supersonic jets

Jegede, Olaseinde January 2016 (has links)
A dual-axis fluidic thrust vectoring (FTV) system is proposed where the supersonic propulsive jet of an aircraft is exhausted over a scarfed (swept), curved surface to produce flight control moments in both the pitch and yaw axes. This work contributes towards practical dual-axis FTV through expansion of fundamental curved-wall jet (CWJ) understanding, development of the novel Superimposed Characteristics technique for supersonic nozzle design, and performance evaluation of an experimental scarfed curved wall FTV configuration. Previous work has suggested that the use of a sheared exhaust velocity profile improves the attachment of supersonic jets to curved surfaces; however, evidence to support this is limited. To address this, an inviscid numerical CWJ model was developed using the two-dimensional method of characteristics. A major outcome is improved understanding of the effect of exhaust velocity profile on CWJ wave structure and subsequent jet attachment. A sheared velocity exhaust is shown to generate a wave structure that diminishes adverse streamwise pressure gradients within a supersonic curved-wall jet. This reduces the likelihood of boundary layer separation and as a result, a sheared exhaust velocity CWJ is expected to be less readily separated compared to other exhaust velocity profiles. A novel method termed Superimposed Characteristics was developed for the low-order design of supersonic nozzles with rectangular exits. The technique is capable of generating 3D nozzle geometries based on independent exit plane orientation and exhaust velocity distribution requirements. The Superimposed Characteristics method was used to design scarfed rectangular exit nozzles with sheared velocity exhaust profiles. These nozzles were then evaluated using finite volume computational methods and experimental methods. From the analysis, the Superimposed Characteristics method is shown to be valid for preliminary nozzle design. Experimental methods were used to study the on- and off-design attachment qualities of uniform and sheared velocity exhaust jets for a FTV configuration with an external curved wall termination angle of 90 degrees and scarf angle of 30 degrees. Experiments at the on-design nozzle pressure ratio (NPR) of 3.3 demonstrated pitch and yaw jet deflection angles of 78 degrees and 23 degrees respectively for the uniform exhaust velocity CWJ. The sheared exhaust velocity CWJ achieved lower pitch and yaw deflection angles of 34 degrees and 14 degrees respectively at the same on-design NPR. The lower jet deflection angles observed for sheared exhaust velocity jets is inconsistent with the CWJ model prediction of reduced adverse streamwise pressure gradients; however, there was insufficient experimental instrumentation to identify the cause. In the off-design experiments, the uniform exhaust velocity CWJ was observed to detach at an NPR of 3.6, whilst the sheared exhaust velocity CWJ remained attached at NPRs in excess of 4. The capability of sheared exhaust velocity CWJs to remain attached at higher NPRs is consistent with the analytical theory and the CWJ model predictions. An actuation study was carried out to achieve controlled jet detachment using secondary blowing injected normal to the curved wall. Full separation of the wall jets was achieved downstream of the injection point. This provided vectoring angles of more than 20 degrees in pitch and 10 degrees in yaw, exceeding expected vectoring requirements for practical aircraft control. At the on-design NPR, the uniform and sheared exhaust velocity jets required secondary blowing mass flow rates of 2.1% and 3.8% of the primary mass flow respectively to achieve full separation.
89

La fluidité architecturale : histoire et actualité du concept / Architectural fluidity : history and topicality of the concept

Voda, Irina Ioana 11 December 2015 (has links)
La « fluidité architecturale » est un oxymore, délibérément choisi, pour mettre l'accent sur les valences de fluidité par rapport aux caractéristiques intrinsèques de l'architecture : comparée aux autres domaines artistiques (littérature, arts plastiques, danse, théâtre, cinéma, photographie, etc.), l’architecture n'est pas seulement pensée, interprétée ou illustrée, mais elle est également construite, habitée et solide. Puisque la fluidité architecturale est une métaphore et la notion de fluidité est abstraite par rapport à l’architecture, ce terme est relié, par une analogie à la mécanique des fluides, aux processus plus concrets qui peuvent être retrouvés en physique. En admettant que l’association des termes « fluide-solide » peut être confuse, la première partie de cette thèse est consacrée à définir la « fluidité » et à identifier ses racines dans l’histoire de l’architecture. La deuxième partie se concentre sur l’analyse « fluidique » d’une série de vingt projets contemporains. Cette analyse, fondée sur les discours architecturaux des concepteurs, détermine le degré de fluidité présente dans la production architecturale contemporaine et établit de nouvelles correspondances entre les différents projets. Cette thèse constitue à la fois un travail sur un concept théorique (par l’analogie avec la mécanique des fluides) et sur une manière de représenter la pensée du projet (par l’analyse fluidique). / "Architectural fluidity" is an oxymoron, chosen deliberately in order to emphasize the fluidity expressions related to the intrinsic characteristics of architecture: compared to other arts (literature, visual arts, dance, theater, cinema, photography etc.), architecture is not only thought, interpreted or illustrated, but also is built, inhabited and solid. Considering architectural fluidity as a metaphor and the idea of fluidity as an abstract architectural concept, this term is associated by analogy to fluid mechanics to processes with accurate explanations found in physics. Assuming that the association of the two terms "fluid-solid" can be confusing, the first part of this thesis concerns with the definition of "fluidity" and the identification of its origins in the history of architecture. The second part focuses on the "fluidic" analysis through twenty contemporary projects. This analysis, which is based on the architectural dissertation of designers, determines the degree of fluidity in contemporary architectural production and establishes new connections between different projects.This thesis focuses on both theoretical concepts (by analogy to fluid mechanics) and developing a method to represent the conceptual process of the project (the fluidic analysis).
90

Microfabrication of Plasmonic Biosensors in CYTOP Integrating a Thin SiO2 Diffusion and Etch-barrier Layer

Hanif, Raza January 2011 (has links)
A novel process for the fabrication of Long Range Surface Plasmon Polariton (LRSPP) waveguide based biosensors is presented herein. The structure of the biosensor is comprised of Au stripe waveguide devices embedded in thick CYTOP claddings with a SiO2 solvent diffusion barrier and etch-stop layer. The SiO2 layer is introduced to improve the end quality of Au waveguide structures, which previously deformed during the deposit of the upper cladding process and to limit the over-etching of CYTOP to create micro-fluidic channels. The E-beam evaporation method is adapted to deposit a thin SiO2 on the bottom cladding of CYTOP. A new micro-fluidic design pattern is introduced. Micro-fluidic channels were created on selective Au waveguides through O2 plasma etching. The presented data and figures are refractive index measurements of different materials, thickness measurements, microscope images, and AFM images. Optical power cutback measurements were performed on fully CYTOP-cladded symmetric LRSPP waveguides. The end-fire coupling method was used to excite LRSPP modes with cleaved polarization maintaining (PM) fibre. The measured mode power attenuation (MPA) was 6.7 dB/mm after using index-matched liquid at input and output fibre-waveguide interfaces. The results were compared with the theoretical calculations and simulations. Poor coupling efficiency and scattering due to the SiO2 are suspected for off-target measurements.

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