Ce travail s'intéresse à la compréhension du comportement des flammes non-prémélangées issues d'un jet de méthane assisté par un coflow d'air dilué avec du CO2, ou d'autres gaz chimiquement inertes pour discriminer les différents phénomènes impliqués dans la dilution. Les phénomènes transitionnels, décrochage et extinction, quantifiés par des limites de stabilité, sont analysés à l'aide de grandeurs physiques représentatives. Le domaine de stabilité de flamme est limité par des surfaces 3D dans le domaine physique ( Qdiluant/Qair (taux de dilution), Uair (vitesse d'air), UCH4 (vitesse de méthane)), révélant un effet compétitif entre l'aérodynamique et la dilution. Des cartographies génériques de décrochage et d'extinction communes à tous ces diluants sont proposées. Des grandeurs liées à la stabilisation sont toutes soumises à des lois d'évolution auto-simlilaires. Il en ressort que la vitesse de propagation de flamme est l'élément clé du mécanisme de stabilisation lors de la dilution. / This work focuses on the understanding of the behaviours of non-premixed methane flame inside an air coflow diluted by carbon dyoxide (CO2) or by other chemically inert diluents in order to discriminate different phenomena involved in dilution. Transitional phenomena (liftoff and extinction) quantified trough the stability limits, are analyzed trough representative physical quantities. The flame stability domain is limited by 3D-surfaces (liftoff and extinction) in the physical domain (Qdiluant/Qair (dilution level), Uair (air velocity), UCH4 (methane velocity)) revealing a competitive effect between aerodynamics and dilution. Generic diagrams of flame liftoff and extinction are proposed for all the diluents. Physical quantities related to flame stabilization process are all submitted to, regardless of diluent, self-similar laws. This is explained by flame burning velocity which is considered as the key element in the flame stabilization mechanism with air-side dilution.

L’évolution des lois relatives à l’utilisation de produits biocides impose d’étudier des méthodes innovantes de traitement du bois. Dans ce contexte, les travaux de recherche présentés s’intéressent à une nouvelle alternative dite « non-biocide » impliquant la fabrication de composites bois massif / polymères obtenus par imprégnation de monomères et polymérisation in situ provoquée par chauffage. Le méthacrylate de méthyle, quatre acrylates organiques et trois acrylates hydrosolubles, ainsi que l’alcool furfurylique ont été testés. Les composites fabriqués ont été caractérisés : le polymère est bien présent dans le bois et il peut être résistant au lessivage à l’eau. Le bois a été densifié, les composites sont alors moins hydrophiles et plus stables dimensionnellement ; les propriétés mécaniques sont améliorées. Le traitement peut induire une durabilité conférée élevée. Parallèlement, une méthode d’imprégnation innovante a été testée : l’imprégnation axiale. Ce procédé consiste en l’imprégnation basse pression de billons de bois vert par une solution de traitement transitant via les voies naturelles de circulation de la sève. Des billons ont été imprégnés avec une solution de cuivre, dosé ultérieurement afin de s’assurer de la bonne répartition du produit dans le bois ; cela a permis la validation du procédé d’imprégnation axiale pour le hêtre, le charme et le bouleau. Enfin, des composites ont été fabriqués par imprégnation axiale de solutions aqueuses polymérisables à base d’alcool furfurylique ; ils sont résistants à la lixiviation à l’eau et moins hydrophiles que le bois naturel. Leur durabilité face aux champignons lignivores est améliorée, particulièrement dans le cas du traitement le plus concentré / The evolution of laws on the use of biocide products makes it necessary to explore innovative methods of treating wood. In this context, the presented research focuses on a new alternative called a "non-biocide" treatment method involving the manufacture of solid wood-polymer composites obtained by impregnation of monomers and in situ polymerization caused by heating. Methyl methacrylate, four organic acrylates and three water-soluble acrylates, and furfuryl alcohol were tested. Composites manufactured were characterized: the polymer is present in the timber and may be resistant to leaching in water. Wood has been densified, while the composites are less hydrophilic and more dimensionally stable; the mechanical properties are improved. Treatment can induce high durability. Otherwise, an innovative method of impregnation was tested: axial impregnation. This process consists in the low-pressure impregnation of green wood ridges by treatment solution transiting via natural pathways of sap circulation. Ridges were impregnated with a copper solution, later determined to ensure good distribution of the product in the timber; this allowed the validation of the axial impregnation method for beech, hornbeam and birch. Finally, the composites were produced by axial impregnation of polymerizable aqueous solutions based on furfuryl alcohol; they are resistant to water leaching and less hydrophilic than the original wood. Their durability in the presence of wood-destroying fungi is improved, particularly in the case of the more concentrated treatment

Les nouvelles molécules thérapeutiques présentent la plupart du temps une faible solubilité aqueuse, à l’origine d’une biodisponibilité restreinte lors de leur administration orale. La réduction de taille des cristaux de substance active à l’échelle submicronique (= production de nanocristaux) s’est imposée comme une voie majeure de formulation au cours de ces dernières années.Afin de pallier des problèmes d’instabilité et d’aboutir à des formes solides pratiques d’utilisation pour les patients, une étape de séchage est généralement effectuée après production des nanocristaux en suspension. L’objectif principal de cette étape est de générer un produit présentant à la fois des propriétés facilitant le déroulement d’étapes procédés avales mais aussi et surtout de prévenir l’agrégation des nanocristaux au risque de compromettre leur dissolution après administration.Plusieurs techniques sont aujourd’hui utilisées dans l’industrie pharmaceutique telle que l’enrobage/granulation en lit d’air fluidisé et le spray drying. Parallèlement à l’élaboration d’une « formulation standard » pour ces deux méthodes de référence, deux techniques innovantes de lyophilisation ont été investiguées dans ce travail. La stabilisation de nanocristaux de kétoconazole par cryopelletization et active freeze drying a été démontrée et les paramètres clefs identifiés. Les produits générés par ces deux techniques, respectivement sous forme de pellets ou de poudre fine, ont été comparés à ceux conçus par enrobage en lit d’air fluidisé et spray drying. En conclusion, ces travaux indiquent que la cryopelletization et l’active freeze drying se positionnent comme des procédés d’intérêt de seconde intention, permettant de traiter des cas particuliers (molécules sensibles au stress thermique, à l’humidité et/ou couteuses). / Newly active pharmaceutical ingredients very often suffer from low aqueous solubility, a fact that in many cases can lead to poor oral bioavailability. Nanosizing, referring to drug nanocrystals production by size reduction, has demonstrated over the past few years a great potential to overcome this major issue.Since solid oral dosage forms are generally preferred due to stability reasons and patient convenience, the production of nanocrystals in a liquid medium is usually followed by a drying step. The main objective of this drying step is to generate a product suitable for downstream processing operations while at the same time preventing nanocrystal aggregation which can adversely affect the dissolution performance of the dry product in vivo.Several drying techniques such as spray drying and coating/granulation in fluidized bed have been successfully implemented in the pharmaceutical industry. In this work, two innovative freeze drying techniques were investigated and compared to the two above mentioned reference methods. The suitability of cryopelletization and active freeze drying to stabilize ketoconazole nanocrystals has been demonstrated and the key process parameters identified. The formulations generated by these two innovative techniques in the form of pellets or fine powder particles, respectively, were compared to the previously manufactured by fluidized bed and spray drying. In conclusion, this work presents cryopelletization and active freeze drying as suitable second-line processes with potential to address the drying of formulations containing problematic molecules sensible to thermal stress, moisture and/or presenting high production costs.

We present the analysis for the higher order continuous Galerkin−Petrov (cGP) time discretization schemes in combination with the one-level local projection stabilization in space applied to time-dependent convection-diffusion-reaction problems. Optimal a priori error estimates will be proved. Numerical studies support the theoretical results. Furthermore, a numerical comparison between continuous Galerkin−Petrov and discontinuous Galerkin time discretization schemes will be given.

This diploma thesis is divided into two main parts. The first part describes issues of the proposal of water management measures in land consolidation process. Second part deals with the conceptual proposal of water management measures in the specific cadastral area. This part also include graphic attachments.

Improvement of the current double inverted pendulum model on a cart as well as a new LQG control and swing-up realization are the main goal of this thesis. Movement of the cart is driven by DC motor and gear belt mechanism. At first the control algorithms were simulated in Simulink program and then also implemented into the real system with MF624 card.

Within the master’s thesis there is comparison of different structures of ARC oscillators with respect to their harmonic distortion. Individual blocks of oscillator are analyzed. Attention is paid to choosing and design of suitable ARC filter structure and possibilities of its tuning. Also possibilities of stabilization of amplitude are analyzed. Different types of controlled amplifiers and circuits for controlling of their amplification are discussed. Next captures are focused to designing and simulation of the ARC oscillator. The oscillator can be tuned in the frequency range from 100 Hz to 20 kHz with harmonic distortion smaller than 1%. At the end of the thesis, practical realization of the proposed circuit is described. Also results of the measurement of parameters of the oscillator are given.

This work deals with using modern active functional blocks in electronic circuits. These blocks have better features than classical operational amplifiers and are characterized especially by working in current mode. Therefore these blocks can be used in higher frequencies. Using those blocks it is possible to design e.g. electronically variable-frequency filters of types low-pass filter, high-pass filter, band-pass filter, etc. Then it is also possible to easily realize electronically variable-frequency oscillators. This work is focused on some of these blocks, their basic characteristics and principles. Also three oscillators with current conveyors of second generation are designed. Its made simulation, sensitivity and tolerance analysis and magnitude stabilization. Everything is performed in OrCAD PSpice program. These made oscillators are electronic tunable in the band frequency ones of MHz.

This thesis deals with digital image stabilization. It contains a brief overview of the problem and available methods for digital image stabilization. The aim was to design and implement image stabilization system in JAVA, which is designed for RapidMiner. Two new stabilization methods have been proposed. The first is based on the motion estimation and motion compensation using Full-search and Three-step search algorithms. The basis of the second method is the detection of object boundaries. The functionality of the proposed method was tested on video sequences with contain visible shake of the scene, which has beed created for this purpose. Testing results show that with the proper set of input parameters for the object border detection method, successful stabilization of the scene is achieved. The rate of error reduction between images is approximately about 65 to 85%. The output of the method is stabilized image sequence and a set of metadata collected during stabilization, which can be further processed in an environment of RapidMiner.

The master thesis deals with design and realization of stabilizing and autopilot system, which is used in radio controlled model planes. The thesis contains a proposal of hardware platform, which is able to control the plane model based on data measured from a sensor system. Moreover, this thesis describes a software implementation of individual modules, which is measured the onboard values. The basic principles of stabilization and autonomous flight control are also summarized. In conclusion, the system is subjected to flight tests.