Internal waves are ubiquitous features in coastal marine environments and have been observed to mediate vertical distributions of zooplankton in situ. Internal waves create fine-scale hydrodynamic cues that copepods and other zooplankton are known to sense, such as fluid density gradients and velocity gradients (quantified as shear deformation rate). The role of copepod behavior in response to cues associated with internal waves is largely unknown. The objective is to provide insight to the bio-physical interaction and the role of biological versus physical forcing in mediating organism distributions. We constructed a laboratory-scale internal wave apparatus to facilitate fine-scale observations of copepod behavior in flows that replicate in situ conditions of internal waves in a two-layer stratification. Three cases were chosen with density jump of 0.75, 1.0, and 1.5 sigma-t units. Analytical analysis of the two-layer system provided guidance to the target forcing frequency needed to generate a standing internal wave with a single dominate frequency of oscillation. Flow visualization and signal processing of the interface location were used to quantify the wave characteristics. The results show a close match to the target wave parameters. Marine copepod (mixed population of Acartia tonsa, Temora longicornis, and Eurytemora affinis) behavior assays were conducted for three different physical arrangements: (1) no density stratification, (2) stagnant two-layer density stratification, and (3) two-layer density stratification with internal wave motion. Digitized trajectories of copepod swimming behavior indicate that in the control (case 1) the animals showed no preferential motion in terms of direction. In the stagnant density jump treatment (case 2) copepods preferentially moved horizontally, parallel to the density interface. In the internal wave treatment (case 3) copepods demonstrated orbital trajectories near the density interface. Further analysis showed that the copepods swim closer to the interface in the presence of internal waves.

This diploma thesis deals with methodology of thin film thickness determination using X-ray radiation of silver anode which provides radiation with energy of 2984,3 eV. This energy is twice as high as the standard aluminium radiation which allows a measurement of new photoelectron lines with higher bonding energy and it also provides thanks to the higher photoelectron energy greater information depth. In order to get the right results it was necessary to calibrate the spectrometer Kratos Axis Supra in the silver anode mode first and found out the form of the transmission function. The determination of the thickness of the thin layer was demonstrated by the comparation of the ratio of different photoelectron lines intensities with the theoretical model. For that purpose was specifically used the Si 1s and Si 2p peak bound in the substrate in the Si-Si bonding or in the thin oxid layer in the Si-O bonding. The results show that for thin SiO2/Si film thickness determination is the best to use the intensity ratio of only one photoelectron line. A silver anode however provides greater information depth.

Les nanoparticules de métaux nobles possèdent des propriétés optiques étonnantes. Sous l’effet de la lumière, elles sont capables de résonner pour générer des plasmons de surface localisés. Ces plasmons absorbent ou diffusent la lumière aux longueurs d’ondes de ces résonnances et sont fortement dépendants de la forme, de la taille et de l’environnement des nanoparticules. Dans ce manuscrit, elles sont impliquées dans la conception de matériaux furtifs à des fins militaires.Des nanoparticules d’argent de formes contrôlées ont été associées à un polymère pour élaborer de nouveaux matériaux hybrides déposables par voie liquide sous la forme de couches minces.Un absorbeur quasi-parfait (98,8%) sur une gamme étroite de longueur d’onde a été obtenu en maintenant une très bonne dispersion des nanoparticules dans la couche, alors qu’un absorbeur large bande efficace (~90%) sur toute la gamme spectrale du visible a été réalisé en provoquant l’agrégation des nanoparticules. Une étude qualitative par microscopie et spectroscopie sur la densité et l’organisation des nanoparticules au sein de la couche mince a mis en évidence la présence de couplages plasmoniques de natures et d’intensités différentes en fonction de l’espacement entre les cubes. Il a été montré que les propriétés optiques mesurées étaient indépendantes de la nature du substrat utilisé, mais aussi indépendantes de l’angle de la lumière incidente sur une large gamme angulaire. Enfin, des systèmes multicouches déposés par voie liquide ont été explorés afin d’étendre l’absorption des couches jusqu’au proche infrarouge par l’ajout de matériaux tel que le l’oxyde de tungstène. / Nanoparticles of noble metals have unexpected optical properties. Under the effect of light, they are able to resonate, generating localized surface plasmon resonances that are used in many applications. These plasmons absorb and scatter the light at the wavelengths of these resonances and are highly dependent on the shape, the size and the environment of the nanoparticles. In this thesis, they are applied for the design of stealth materials for military purposes. For this, controlled shapes of silver nanoparticles were blended within a polymer to develop new hybrid materials that are solution-processed as thin layers. A quasi-perfect absorber (98,8%) in a precise range of wavelengths has been obtained by maintaining well-dispersed nanoparticles in the layer, while an effective broadband absorber (~90%) over the entire visible range has been achieved by triggering the aggregation of the nanoparticles. Microscopy and spectroscopy qualitative studies performed on the density and organization of the nanoparticles within the thin layers revealed the presence of plasmonic couplings of different natures and intensities as a function of the spacing between the cubes. It has been shown that the optical properties measured are independent of the nature of the substrates used and independent of the angle of the incident light on a wide angular range. Finally, solution-processing of multilayers systems was explored to extend the absorption of the layers to the near infrared by the addition of other materials such as tungsten oxide.

Les composants optiques (miroirs, lentilles, hublots…) présents sur les chaînes du Laser Mégajoule (LMJ) sont susceptibles de s’endommager sous flux laser de forte énergie en particulier à la longueur d’onde 351 nm. Les dommages se présentent sous la forme de cratères de quelques micromètres de diamètre qui apparaissent et croissent en face arrière des optiques en silice. Dans ce contexte, le but de ces travaux est de développer des revêtements de protection qui visent, par leurs propriétés d’amortissement au choc, d’autocicatrisation, ou de post réparation, à limiter la croissance de ces dommages. Des couches minces, de quelques micromètres d’épaisseur ont été préparées par procédé sol-gel et déposées sur la face arrière des optiques. L’élaboration de ces couches s’effectue par la synthèse sol-gel d’une solution composée d’un précurseur de silice et d’un élastomère polydiméthylsiloxane (PDMS). / The optical devices (lents, mirrors, portholes…) that are set on the chains of the Laser Megajoule (LMJ) may be damaged by the high energy laser beam especially around the UV wavelength of 351 nm. The damages are micronics craters on the rear of the optics that grows exponentially after each laser shots. The study aim at developing some optical thin coatings on the rear of the optical substrates to prevent the growth of the damage by amortizing the laser shockwave, self-healing the craters that has appeared, or repairing the laser hole after the damage occurs. The thin coatings have been prepared by a sol-gel method by using silica precursor and a polydimethylsiloxane (PDMS) elastomer. The two species reacted together to get a hybrid organic-inorganic Ormosil (organically modified silica) material, by creating a silica network linked to the PDMS species with covalent and hydrogens bounds. The thin layers are obtained from the sol-gel solution by using a dip and spin coating method.

In the current study, behavioral responses of several species of calanoid copepods to mimics of oceanographic structure were observed and evaluated in the context of foraging and aggregation. Zooplankton distributions in oceanic habitats are often attributed to physical forcing; however, physical factors only act to drive ecological patterns at large scales (m to km). At fine to intermediate scales (cm to m) zooplankton behavior is believed to govern observed distributions, but the mechanisms and ecological significance of these behaviors are not well understood. In a water column, biological activity is often concentrated into one or a few regions, called thin layers, on the order of a meter thick, and zooplankton, such as copepods, must be able to reliably locate and exploit these patches for survival. Thin layers commonly are associated with oceanic structure such as flow gradients, fluid density jumps, or chemical composition gradients. Utilization of mechanosensory or chemosensory cues associated with thin layers may increase foraging success, thus translating into a significant ecological advantage. A laboratory apparatus was developed to create isolated and combined thin layer properties. Copepods then were exposed to laboratory mimics of thin layers. All of the tested species of copepods exhibited behavioral responses associated with area-restricted search behavior to one of the physical gradients (flow velocity or fluid density), but not both. Similar responses were observed for chemical exudate layer experiments and included increased proportional residence times, swimming speeds, and turn frequency. Food layers induced feeding responses from all tested species (increased proportional residence time, decreased swimming speed). Responses to various combinations of gradients were not fully synergistic, but suggested that some copepods employ a cue hierarchy to locate food-rich areas. Velocity or density gradients acted as initial cues for narrowing search regions, while chemical exudates induced responses that strengthened or removed the initial reactions. A simple foraging model was used to illustrate how such behavioral changes can lead to observed aggregations at larger temporal and spatial scales. Consequently, these results suggest that individual responses to oceanographic structure may have far reaching influence on population dynamics, succession, and biodiversity in coastal and pelagic ecosystems.

Les revêtements semi-conducteurs déposés sur des substrats souples sont utilisés dans différentes applications de haute technologie, par exemple pour la fabrication de composants micro-électroniques flexibles ou de cellules photovoltaïques flexibles. Sous un chargement de traction, ces revêtements subissent un endommagement caractérisé par l'apparition de multiples fissures sur leur surface avec ou sans délaminage à l'interface film/substrat. A la fin du processus de la multi-fissuration, une distance caractéristique entre les fissures peut être mesurée. Cette distance dépend principalement de l'épaisseur du film et du comportement mécanique du substrat.Dans ce projet, une étude expérimentale sur des monocouches d'oxyde et des multicouches d'oxyde et d'argent de différentes épaisseurs déposées sur deux substrats souples a été menée. Cette étude nous a permis de déterminer le comportement mécanique de chaque substrat, d'identifier les stades de la multi-fissuration des couches minces à savoir un premier stade d'apparition aléatoire de fissures, un deuxième stade de fissuration régulière et un dernier stade de saturation du réseau de fissures. L'influence de l'épaisseur de la couche d'argent a été également étudiée.Nous avons développé un modèle mécanique 2D basé utilisant des zones cohésives pour simuler l'amorçage et la propagation de fissures à travers le film. Ce modèle a permis de simuler numériquement les trois stades de la multi-fissuration des monocouches d?oxyde déposées sur polymère tels qu' observés expérimentalement. Nous avons ensuite réduit le modèle à une cellule représentative permettant de modéliser seulement les deux derniers stades de la multi fissuration. Cette cellule nous a permis d'identifier l'influence des propriétés géométriques et mécaniques des couches minces et de leur substrat sur la distance inter fissures à saturation. L'influence du délaminage interfacial a également été étudié. / Semiconductor coatings deposited on flexible substrates are used in various high-tech applications, for example flexible micro-electronic components or flexible sollar cells.When submitted to large tensile strains, these coatings undergo damage characterized by the appearance of multiple cracks on their surface with or without delamination at the film/substrate interface.At the end of the multi-cracking process, a characteristic distance between cracks can be measured.This distance depends mainly on the thickness of the film and the mechanical behavior of the substrate.In this project, an experimental study on oxide layers and oxide and silver multilayers of different thicknesses deposited on two polymer substrates was carried out.Were able to determine the mechanical behavior of each substrate and to identify the stages of the three stades of multi-cracking of thin layers.A first stade of random appearance of cracks, a second stade of regular cracking and a last stade of saturation of the network of cracks were identified.The influence of the thickness of the silver layer has also been studied.We have developed a 2D based mechanical model using cohesive zones to simulate the initiation and propagation of cracks in the film.Using this model, we successfully simulate the three stages of the multi-cracking of oxide monolayers deposited on polymer as observed experimentally.We then reduced the model to a representative cell allowing only the last two stages of multi-cracking to be modeled. This cell allowed us to identify the influence of the geometric and mechanical properties of the thin layers and their substrate on the distance between cracks to saturation.The influence of interfacial delamination has also been studied.

This diplom theses is concerned with the possibilities of using non-thermal plasma in biomedical and enviromentally friendly applications. The theoretical part is drawn up as research overview of the current knowledge from the stated issue. The practical part is focused on the modification of nanofibres by deposition of TiOx layers.

This master thesis deals with examination of the parameters of low temperature plasma which is used for the deposition of thin layer of ITO. The method which is used in this thesis is the probe diagnostics. This thesis is divided into two parts. The first is the theoretical part, in which the basic parameters of low temperature plasma, principles of the probe diagnostics, and theories for this method are explained. The second part is the practical part, which presents the results of the measurement depending on changes in conditions of deposition.

Cette thèse traite de l'étude de films ultra minces de Fe par réflectivité magnétique résonante de rayons X mous (SXRMR). La technique de SXRMR associe les effets magnéto-optiques aux propriétés de diffusions des rayons X, ce qui permet sonder les propriétés magnétiques avec une résolution spatiale en profondeur. Un profil magnétique résolu en profondeur est donc dérivé des expériences, permettant d'étudier les effets des interfaces sur l'homogénéité des propriétés magnétiques. Dans un premier temps nous présentons l'étude d'un film mince de Fe sur un substrat vicinal d'Ag(116) recouvert par quinze monocouches d'Au. Cette étude révèle que l'aimantation est augmentée de 20 à 30$\%$ dans les deux à trois monocouches proches des interfaces d'Au et d'Ag, quelque soit la température et l'épaisseur de la couche de Fe. Nous avons également mis en évidence une inhomogénéité de la composante hors du plan à basse température pour des échantillons ayant un axe de facile perpendiculaire aux marches : la composante de l'aimantation hors du plan est de plus en plus grande lorsqu'on se rapproche du substrat vicinal d'Ag. Dans un deuxième temps, nous présentons l'étude d'un film mince de six monocouches de Fe sur du Cu(100) et recouvert par une couche d'Au. En utilisant une approche originale de contrainte sur les paramètres magnétiques, nous avons pû mettre en évidence que la dépendance de l'aimantation en fonction de la température n'était pas la même selon la position de la monocouches dans le film mince de Fe, comme prédit théoriquement par Sandratski. / This thesis deals about depth resolved magnetic profile of ultrathin Fe layers studied by soft X-ray Resonant Magnetic Reflectivity (SXRMR). This SXRMR technique combines magneto-optic effects to X-ray scattering allowing to be sensitive to magnetic properties as well as to be depth resolved. For each experiments, the depth resolved magnetic profile found allows to study interfaces effect on the homogeneity of magnetic properties. First, we present the study of a thin film of Fe grown on a vicinal substrate of Ag(116) and covered by fifteen monolayers of Au. This study reveal that the magnetization is enhanced of 20 to 30$\%$ int the two to three monolayers near both interfaces, whatever the temperature and the Fe thickness are. We have also discover an inhomogeneity of the magnetic out of plane component at low temperature for sample where the magnetization easy axis is perpendicular to the steps : the magnetic out of plane component is more and more important when we go strait to the vicinal substrate of Ag. Second, we show the study of a thin film of six monolayers of Fe grown on a Cu(100) substrate and covered by a Au layer. Using a new way of strain on magnetic parameter we have highlighted that the temperature dependance of the magnetization is not the same depending ont the position of the monolayer inside the Fe thin film as predicted by the theory of Sandratski.

This work deals with the optimization of the preparation process of WO3 photoanodes nad their characterization. For compositions were prepared, which were applied to a substrate via spin-coating process and subsequently annealed at 450 °C. The length of milling of precursor particles contained in the coating formulations determined properties of deposited layers. were examined for. The additivity of the individual compositions was also observed. The structure of the layers was observed by optical microscopy and scanning electron microscopy (SEM), their composition by the X-ray diffraction (XRD) and their thickness and surface roughness was defined by contact profilometry. Photoelectrochemical properties of the prepared layers were also investigated by linear voltametry and chronoamperometry.