Дисертації з теми "Interactions directes de surface"
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Wu, Hung-Jen. "Direct measurements of ensemble particle and surface interactions on homogeneous and patterned substrates." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3747.
Everett, William Neil. "Evanescent wave and video microscopy methods for directly measuring interactions between surface-immobilized biomolecules." Thesis, [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1585.
Jespersen, Michael L. 1979. "Engineering the macro-nano interface: Designing the directed self-assembly and interfacial interactions of gold nanoparticle monolayers." Thesis, University of Oregon, 2008. http://hdl.handle.net/1794/7504.
Gold nanoparticles in the 1-2 mn core diameter size regime have generated a great deal of interest due to their size-dependent electronic, optical, and catalytic properties. A number of proof-of-concept experiments have demonstrated that small metal nanoparticles can be integrated into single electron transistors and optical waveguides. Still, reliable incorporation of gold nanoparticles into devices requires practical methods for their assembly on surfaces. Additionally, surface modification methods must be developed in order to control interparticle interactions and nanoparticle-environment interactions for use in sensing and catalysis. In this research, nanoparticle-substrate interactions were utilized to assemble surface-bound gold nanoparticle monolayers with interesting electronic and catalytic properties. Gold nanoparticles (1.5 nm diameter) with a thiol ligand shell containing phosphonic acid terminal functionality were synthesized and assembled selectively onto hafnium-modified silicon dioxide substrates through bonding of the terminal phosphonate to Hf(IV) surface groups. By increasing the surface coverage of Hf, it was possible to assemble monolayers of gold nanoparticles dense enough to exhibit nonlinear current-voltage properties across a 5-μm electrode gap at room temperature. Moreover, by taking advantage of the selectivity of this ligand shell for ZnO over SiO 2 , small gold nanoparticles were utilized as catalysts for selective growth of patterned, vertical ZnO nanowire arrays. In addition to engineering nanoparticle-substrate interactions, new surface modification methods were introduced to manipulate the interaction of the as-deposited gold nanoparticle monolayers with the environment. For example, thiol-thiol ligand exchange reactions were carried out on the surface-bound nanoparticle monolayers by immersion in dilute thiol solutions. Contact angle and XPS measurements indicate that the upper, surface-exposed phosphonic acid ligands are replaced by incoming thiol ligands. TEM measurements indicate that nanoparticle monolayers remain surface-bound and are stable to this exchange process, as the average particle size and surface coverage are preserved. As another example, the ligand shell can be partially removed by UV/ozone treatment to expose bare gold cores to the surrounding environment. On metal oxide substrates, this approach activates the particles for room temperature oxidation of carbon monoxide to carbon dioxide. This dissertation includes both my previously published and my co-authored materials.
Adviser: James E. Hutchison
Zhang, Jing. "Design and implementation of DNA-Directed Immobilisation (DDI) glycoarrays for probing carbohydrate-protein interactions." Phd thesis, Ecole Centrale de Lyon, 2010. http://tel.archives-ouvertes.fr/tel-00605541.
Haidar, Ali. "Numerical simulation of nonlinear shallow-water interactions between surface waves and a floating structure." Electronic Thesis or Diss., Université de Montpellier (2022-....), 2022. https://ged.scdi-montpellier.fr/florabium/jsp/nnt.jsp?nnt=2022UMONS093.
In this Ph.D., we investigate two main research problems: (i) the design of stabilization patches for higher-order discontinuous-Galerkin (DG) methods applied to highly nonlinear free-surface shallow-water flows, (ii) the construction of a new numerical approximation strategy for the simulation of nonlinear interactions between waves in a free-surface shallow flow and a partly immersed floating object. The stabilization methods developed in the first research line are used in the second part of this work.High-order discontinuous-Galerkin (DG) methods generally suffer from a lack of nonlinear stability in the presence of singularities in the solution. Such singularities may be of various kinds, involving discontinuities, rapidly varying gradients or the occurence of dry areas in the particular case of free-surface flows. In the first part of this work, we introduce two new stabilization methods based on the use of Finite-Volume Subcells in order to alleviate these robustness issues. The first method relies on an a priori limitation of the DG scheme, together with the use of a TVB slope-limiter and a PL. The second one is built upon an a posteriori correction strategy, allowing to surgically detect the incriminated local subcells, together with the robustness properties of the corresponding lowest-order Finite-Volume scheme. This last strategy allows to ensure the nonlinear stability of the DG scheme in the vicinity of discontinuities, as well as the positivity of the discrete water-height, while preserving the subcell resolution of the initial scheme. This second strategy is also preliminary investigated in the two dimensional horizontal case. An extensive set of test-cases assess the validity of this approach.In the second part, we introduce a new numerical strategy designed for the modeling and simulation of nonlinear interactions between surface waves in shallow-water and a partially immersed surface piercing object. At the continuous level, the flow located in the textit{exterior} domain is globally modeled with the nonlinear hyperbolic shallow-water equations, while the description of the flow beneath the object reduces to a nonlinear ordinary differential equation. The coupling between the flow and the object is formulated as a free-boundary problem, associated with the computation of the time evolution of the spatial locations of the air-water-body interface. At the discrete level, the proposed formulation relies on an arbitrary-order discontinuous Galerkin approximation, which is stabilized with the a posteriori Local Subcell Correction method through low-order finite volume scheme introduced in the first part. The time evolution of the air-water-body interface is computed from an Arbitrary-Lagrangian-Eulerian (ALE) description and a suitable smooth mapping between the original frame and the current configuration. For any order of polynomial approximation, the resulting algorithm is shown to: (1) preserves the Discrete Geometric Conservation Law, (2) ensures the preservation of the water-height positivity at the subcell level, (3) preserves the class of motionless steady states (well-balancing), possibly with the occurrence of a partially immersed object.Several numerical computations and test-cases are presented, highlighting that the proposed numerical model(1) effectively allows to model all types of wave / object interactions, (2) efficiently provides the time-evolution of the air-water-body contact points and accordingly redefine the new mesh-grid thanks to ALE method (3) accurately handles strong flow singularities without any robustness issues, (4) retains the highly accurate subcell resolution of discontinuous Galerkin schemes
Awassa, Jazia. "Mécanismes antibactériens des hydroxydes doubles lamellaires à base de zinc." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0155.
Layered double hydroxides (LDH) are solid compounds constituted by the stacking of divalent M(II) and trivalent M(III) metal hydroxide sheets separated by an interlayer of anions and water molecules. Due to the versatility of LDH in terms of their tunable physico-chemical properties, a growing interest arises for investigating their different antibacterial activity mechanisms. This thesis work aims at studying the different proposed hypotheses explaining the antibacterial effect of pristine zinc-based LDHs: (1) direct interactions between the surface of LDH and bacterial cell walls, (2) release of constituent divalent metal ions, (3) generation of reactive oxygen species (ROS). First a global investigation was performed to determine the different physico-chemical parameters influencing the antibacterial activity of pristine M(II)Al(III) LDHs (M= Zn, Cu, Ni, Co, Mg). The antimicrobial effect of LDHs against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria was linked in the first place to the nature of divalent metal itself, and to the amount of released M2+aq ions into the culture media in the second place. This effect was more easily identified in Zn(II)-based LDHs possessing the strongest antibacterial activity and whose antibacterial properties depended on their release profile of Zn2+aq ions (Mechanism 2) initially controlled by the different physico-chemical parameters. Moreover, the direct contact mechanism (Mechanism 1) was validated for Zn(II)-based LDHs by comparing the antibacterial activity of micron-sized LDHs against S. aureus to that of LDH nanoparticles (NPs) exhibiting a greater antibacterial effect. The presence of specific surface interactions between Zn(II)-based LDHs and the cell wall of S. aureus was further validated by atomic force microscopy-based force spectroscopy (AFM-FS). The enhancement of the antibacterial properties of Zn(II)-based LDH NPs by ROS generation (Mechanism 3) in presence of UVA light was also assessed. After providing experimental evidences about the three suggested mechanisms, the role of each mechanism contributing to the antibacterial activity of Zn(II)-based LDHs in different antibacterial tests assays was determined
Neltner, Brian. "Creating selective directional interactions with defects caused by subnanometre-ordered ligand domains on the surface of colloidal metal nanoparticles for the purpose of directed self-assembly." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32848.
Includes bibliographical references (p. 42-43).
Introduction: The ability to utilize directional, specific bonds are a fundamental property of atoms which has allowed us to predictably create molecules of consistent geometry and composition for centuries. One fundamental difference between a true atom and a nanoparticle is that to date, nanoparticles do not possess this property.
by Brian Neltner.
S.B.
Rimbault, Charlotte. "Modulation des interactions impliquant les domaines PDZ par une approche d’évolution dirigée." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0438/document.
Complex and dynamic protein-protein interactions are the core of protein-based networks in cells. At excitatory synapses, the postsynaptic density (PSD) is a typical example of protein-based network whose nanoscale structure and composition determines the cellular function. For instance, the dynamic regulation of PSD composition and glutamate receptors movements into or out of the PSD are the base of current molecular theories of learning and memory. In this context, during my PhD, I focused on a class of protein-protein interactions mediated by PDZ domains. Indeed, over the last decade, numerous studies have shown the critical implication of PDZ domain-mediated interactions from the PSD95 scaffolding protein family in the synaptic targeting and anchoring of glutamate receptors. However, in part due to the lack of adapted tools, the molecular mechanisms that dynamically govern their respective synaptic retention remain poorly understood. In order to investigate these PDZ domain-mediated interactions, I developed several selection strategies by phage-display based on the fibronectin type III (FN3) scaffold in order to either target the PDZ domain-binding motifs of the receptors complexes (e.g., stargazin for AMPARs and GluN2A for NMDARs) or the PDZ domains themselves. Using a multidisciplinary approach, my main objectives were to engineer small synthetic antibodies that will allow us to acutely and specifically disrupt or stabilize these protein complexes, as well as monitor endogenous interactions
Took, Roger Kenton. "Surface interaction : separating direct manipulation interfaces from their applications." Thesis, University of York, 1990. http://etheses.whiterose.ac.uk/13997/.
Mohammad, Ali Monadjemi Shirin. "Phototransformation de matières actives à la surface des végétaux . Mécanismes des réactions directes et sensibilisées." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2012. http://tel.archives-ouvertes.fr/tel-00836760.
Gosselet, Adam. "Inversion conjointe d'arrivées réfléchies de surface et d'arrivées directes au puits par tomographie de pente." Paris, ENMP, 2004. http://www.theses.fr/2004ENMP1266.
Seismic tomography, which aims to determine propagation velocities of waves in the subsoil, is a key point in obtaining accurate geological images in petroleum exploration. The methodology proposed here consists in inverting both seismic waves traveltimes and slopes and jointly uses surface data and direct borehole arrivals. These latter allow better reliability of the velocity field because they can provide more accurate values and enhanced depth fitting. Using slopes, they can be retropropagated in the inverted model in order to assess its quality in terms of focusing capability. The method is applied on two data sets. First one provides borehole data only and is unable to correctly constrain model parameters, due to lack of coverage at surface. Second one demonstrates that joint use of surface and borehole data provides enhanced seismic images compared to use of surface data alone
Zidan, M. D. "Gas-liquid surface interactions." Thesis, University of Sussex, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333478.
Nguyen, Minh Quan. "Simulation numérique des interactions fluides-polymères dans le cadre d'une turbulence homogène isotrope." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEC026/document.
No abstract
Hessey, Stephen. "Surface interactions of ionic liquids." Thesis, University of Nottingham, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664318.
Mouncey, Simon Patrick. "Low energy ion-surface interactions." Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333823.
Cotton, Ross Thomas. "Surface interactions of soccer balls." Thesis, Loughborough University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.536210.
Subedi, Laxmi P. "AFM Tip-Graphene-Surface Interactions." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1291144388.
Clowes, Steven Kenneth. "Experimental studies of surface-adsorbate interactions and surface magnetism." Thesis, University of York, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323531.
Ye, Zhou. "Effect of Nanoscale Surface Structures on Microbe-Surface Interactions." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/85387.
Ph. D.
Montagne, Franck. "Elaboration de latex magnétiques à partir d'émulsions directes de ferrofluide : forces de surface entre conjugués particules-oligodésoxyribonucléotides." Lyon 1, 2002. http://www.theses.fr/2002LYO10241.
Melki, Mickaël. "Les interactions directes et indirectes entre idéologie et croissance économique : Cinq essais appliqués au cas français,1870-2011." Paris 1, 2012. https://tel.archives-ouvertes.fr/tel-00767439.
Katuri, Jaideep. "Guiding active particles through surface interactions." Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/663989.
Los organismos y sistemas vivos convierten energía almacenada internamente o derivada de sus alrededores en movimiento de forma continua. Esta actividad puede causar una constante auto-propulsión que lleva a estos sistemas a un estado fuera de equilibrio térmico. Gracias a esto, aparecen un gran número de fenómenos exóticos que no son accesibles para un sistema que se encuentra en equilibrio térmico. En los últimos años se ha clasificado a estos sistemas de no equilibro como “material activa”. La materia activa, por definición, incluye los sistemas compuestos de unidades activas, cada una de ellas capaz de convertir la energía almacenada o del entorno en movimiento sistemático. Existen varios ejemplos que van desde la escala sub-micrométrica, donde podemos encontrar a los microtúbulos asociados a proteínas motoras en el citoplasma, a las grandes escalas, donde se encuentran sistemas más familiares como peces o pájaros, pasando por la escala micrométrica, donde nadan las bacterias. Podemos diferenciar dos temas principales que se manifiestan en todos estos sistemas de materia activa. El primero es la aparición de fenómenos colectivos correlacionados a través de interacciones partícula-partícula, como ocurre en bandadas de pájaros, enjambres bacterianos y la cristalización de partículas auto-propulsadas. El segundo es la capacidad de estas unidades activas de interaccionar con sus alrededores a través del fenómeno de la auto-propulsión, por ejemplo, a través de quimiotaxia o reotaxia, como se puede observar en muchos sistemas biológicos y que ya han sido reportados en varios estudios. En esta tesis, me he enfocado en el estudio de este último tema principal: la interacción de partículas activas con su entorno local. Como modelo de sistema de materia activa, usamos partículas activas coloidales que se propulsan gracias al fenómeno de auto-difusioforesis. Estas partículas están recubiertas por dos materiales diferentes en cada una de sus caras, y son comúnmente llamadas “partículas Janus”. Una de sus caras está recubierta con Pt, material que cataliza la descomposición de H2O2, mientras que la otra cara está recubierta de un material inerte (SiO2). En una solución de H2O2, la reacción que ocurre en la parte catalítica produce un gradiente de concentración de producto a lo largo de la superficie de la partícula e induce un deslizamiento forético que la propulsa. En esta tesis se ha estudiado la dinámica de estas partículas "autoforéticas" cerca de superficies sólidas. De manera natural, las partículas interaccionan con su alrededor debido a los efectos foréticos e hidrodinámicos. Cuando estas partículas se hayan confinadas cerca de una superficie, observamos que se origina en ellas una fuerte interacción de alineamiento. A partir de ello, consideramos interesante diseñar ratchets micro estampados capaces de generar un flujo direccional de partículas activas. Por otra parte, estudiamos la influencia de aplicar un flujo de cizalla externo en la dinámica de las partículas activas cerca de superficies. A consecuencia del flujo externo, encontramos que en el sistema emerge una respuesta fuertemente direccional para las partículas activas en la dirección perpendicular al flujo provocando una migración "cross-stream" de partículas activas.
Kerford, M. "Modelling of energetic molecule-surface interactions." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/843052/.
Thom, Alasdair D. "Analysis of vortex-lifting surface interactions." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/3037/.
Driscoll, Heather Frances. "Understanding shoe-surface interactions in football." Thesis, Sheffield Hallam University, 2012. http://shura.shu.ac.uk/17145/.
Hulot, Florence. "Des chaînes aux réseaux trophiques : rôle de la diversité fonctionnelle dans le fonctionnement des écosystèmes." Paris 6, 2001. http://www.theses.fr/2001PA066440.
Nayakasinghe, Mindika Tilan Abeyrathna. "Fundamental Surface Properties and Gas-Surface Interactions of Two-Dimensional Materials." Diss., North Dakota State University, 2019. https://hdl.handle.net/10365/29325.
ACS-PRF
North Dakota State University. Department of Chemistry and Biochemistry
North Dakota State University. Research and Creative Activity
LEREBOURS, PIGEONNIERE BRIGITTE. "Phototransfert d'electron en micelles directes : polymerisation de tensioactifs, carcterisation de vesicules mixtes." Paris 6, 1987. http://www.theses.fr/1987PA066490.
Musehane, Ndivhuwo M. "Direct numerical simulation of bubble-bubble and droplet-droplet interaction using a Surface Thin Film model." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/22963.
Frühauf, Jens. "Surface dopant interactions in ultra-shallow junctions." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=979061350.
Jarvis, Suzanne Philippa. "Atomic force microscopy and tip-surface interactions." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359441.
Willems, Nathalie. "Molecular dynamics simulations of lipase-surface interactions." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:7765c334-7c02-4190-a4b2-99ad315cfe52.
Agbormbai, Adolf Akombi. "Gas surface interactions in rarefied hypersonic flows." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/46929.
Ioannou, Marina. "Cell surface interactions of Coxsackie A9 virus." Thesis, University of Essex, 2018. http://repository.essex.ac.uk/22325/.
Pavey, Karl David. "Piezoelectric quartz crystal monitoring of surface interactions." Thesis, University of Brighton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299222.
Rêgo, Celso Ricardo Caldeira. "Ab-initio studies of adsorbate-surface interactions." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-29012018-093011/.
Esta tese ajuda a entender as interações entre duas superfícies de carbono. A natureza da interação de átomos ou aglomerados atômicos adsorvidos sobre uma superfície de carbono. Além disso, visa esclarecer a dinâmica de um átomo sendo adsorvido sobre uma superfície metálica. As interações superfície-superfície e átomos-superfícies são importantes por razões que variam desde o interesse industrial até a necessidade acadêmica para compreendê-la profundamente. Entendê-las ainda é um desafio. Diversos trabalhos apresentam medidas experimentais e simulações para as propriedades geométricas e eletrônicas do grafite. Tais medidas diferem em mais ide 40% umas da outra. Isso mostra que nossa compreensão sobre a natureza desse material ainda é bastante pobre. A interação entre pequenos grupos de metais de transição com uma folha de grapheno é outro exemplo em que nosso conhecimento é limitado. Existem muitos estudos teóricos na literatura que descrevem a interação desse tipo de aglomerado com uma folha de grafeno, porém há numerosas discordâncias. Tais controvérsias parecem suplicar por um estudo sistemático. Nesta tese focamos nossos estudos nas interações superfície-superfície e de átomos ou aglomerados atômicos com superfícies de carbono e de um metal. A tese foi dividida em três projetos. O primeiro visa compreender melhor a interação entre as camadas do grafite. No segundo, pretendemos lançar alguma luz no entendimento da interação de átomos e aglomerados atômicos com uma folha de grafeno. Esses dois projetos, são estudados à luz da Teoria do Funcional da Densidade com a inclusão das correções van der Waals (vdW). No Projecto sobre o grafite, mostramos que as propriedades eletrônicas e geométricas dependem do tipo de correção de vdW empregada no cálculo. No projeto sobre átomos e aglomerados atômicos adsorvidos no grapheno, combinamos um modelo modificado de Anderson-Newns para descrever o acoplamento entre um átomo adsorvido e o grafeno. Além disso, encontramos uma competição entre forças quânticas e clássicas, a qual determina o tipo de sítio no qual o átomo prefere ser adsorvido. O último projeto é um estudo dinâmico de um átomo colidindo contra uma superfície metálica. Nesse projeto o foco é posto no cálculo do coeficiente de aderência, o qual mede a taxa de densidade nuclear presa na superfície metálica após a colisão. Resultados preliminares indicam que, uma pequena parte da densidade nuclear permanece aderida ao metal depois da colisão.
Oliveira, Marta Isabel Abreu. "Molecular interactions at the T cell surface." Doctoral thesis, Instituto de Ciências Biomédicas Abel Salazar, 2007. http://hdl.handle.net/10216/7220.
Doherty, Kyle George. "Microplasma technology for influencing cell-surface interactions." Thesis, University of Liverpool, 2014. http://livrepository.liverpool.ac.uk/18213/.
Di, Fino Alessio. "Comparative approach to barnacle adhesive-surface interactions." Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/2838.
Kolasinski, Robert David Goodwin David G. "Fundamental ion-surface interactions in plasma thrusters /." Diss., Pasadena, Calif. : California Institute of Technology, 2007. http://resolver.caltech.edu/CaltechETD:etd-11222006-105854.
Usman, Jauhr. "Quantification of affinity mediated cell/surface interactions." Thesis, University of Bath, 1997. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362307.
Oliveira, Marta Isabel Abreu. "Molecular interactions at the T cell surface." Tese, Instituto de Ciências Biomédicas Abel Salazar, 2007. http://hdl.handle.net/10216/7220.
Jones, Cullen Brandon. "Groundwater-Surface Water Interactions near Mosier, Oregon." PDXScholar, 2016. https://pdxscholar.library.pdx.edu/open_access_etds/3414.
Fernandez, Nicolas. "Etude des interactions gaz - surface par DFT." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4715/document.
The work herein presented deals with the reactivity of surfaces and the gas–surface interaction. This work is connected to different fields of applied science and more specifically to the field of nuclear materials for fusion devices like the International Thermonuclear Experimental Reactor (ITER).Numerical simulations at the atomic scale can provide an in depth understanding of the mechanisms at the origin of experimental observations. More specifically, our skills are about electronic structure calculations and chemical properties modelling; most of the work we produced has been conducted within the framework of the Density Functional Theory (DFT) and statistical thermodynamics. While made of six chapters, the manuscript can be cast in three main parts. The first one is dedicated to the methods used throughout this thesis. The second is devoted to the formation of beryllium carbide from deposited beryllium atoms on graphite surfaces; the reliability of the DFT results was benchmarked and the main steps of the beryllium carbide formation were determined. The third part explores the interaction between hydrogen and metallic tungsten. The formation of vacancies in the material, its impact on the solubility and diffusion of hydrogen in tungsten were investigated, and the results were compared with experiment; an excellent agreement was found
Fernandez, Nicolas. "Etude des interactions gaz - surface par DFT." Electronic Thesis or Diss., Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4715.
The work herein presented deals with the reactivity of surfaces and the gas–surface interaction. This work is connected to different fields of applied science and more specifically to the field of nuclear materials for fusion devices like the International Thermonuclear Experimental Reactor (ITER).Numerical simulations at the atomic scale can provide an in depth understanding of the mechanisms at the origin of experimental observations. More specifically, our skills are about electronic structure calculations and chemical properties modelling; most of the work we produced has been conducted within the framework of the Density Functional Theory (DFT) and statistical thermodynamics. While made of six chapters, the manuscript can be cast in three main parts. The first one is dedicated to the methods used throughout this thesis. The second is devoted to the formation of beryllium carbide from deposited beryllium atoms on graphite surfaces; the reliability of the DFT results was benchmarked and the main steps of the beryllium carbide formation were determined. The third part explores the interaction between hydrogen and metallic tungsten. The formation of vacancies in the material, its impact on the solubility and diffusion of hydrogen in tungsten were investigated, and the results were compared with experiment; an excellent agreement was found
Liang, He. "Control of surface interactions with ultra-violet/ozone modification at polystyrene surface." Thesis, Robert Gordon University, 2014. http://hdl.handle.net/10059/948.
Toquer, Guillaume. "Couplages originaux entre Surfactants et Cristaux Liquides Thermotropes : Microémulsions inverses et émulsions directes." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2006. http://tel.archives-ouvertes.fr/tel-00142098.
La première étude porte sur l'organisation de systèmes lyotropes (surfactants et eau) dans un solvant thermotrope anisotrope (cristal liquide). L'existence d'une phase baptisée « nématique transparente » dans un tel système mixte thermotrope-lyotrope de type microémulsion a été en effet récemment débattue. Des expériences de diffusion dynamique de lumière, au voisinage de la transition isotrope-nématique, laissait supposer l'apparition d'une phase intermédiaire, résultant de la compétition entre l'apparition d'un ordre nématique dans le solvant et des effets d'ancrages sur les agrégats.
Nous avons caractérisé, dans un premier temps, par diffusion de rayonnement X et neutrons, la morphologie et les interactions d'agrégats, composés de bromure de didodecyldimethylammonium (DDAB) et d'eau, dans le cristal liquide 4-n-pentyl-4'-cyanobiphenyl (5CB) en phase isotrope. L'étude de l'évolution des diagrammes de phases couplée à des expériences de diffusion (X, Lumière et neutrons) a permis de montrer que l'ajout de cosurfactants permettait de faire varier continûment la taille des nanoagrégats. L'ensemble de nos données expérimentales s'explique bien par la présence d'interactions fortes de Van der Waals entre micelles, ce qui justifie en particulier l'absence de transition microémulsion/ lamellaire gonflée dans ce système. L'analyse des facteurs de structure a permis par ailleurs de mettre en évidence une seconde interaction attractive entre micelle, causée par les fluctuations paranématiques du cristal liquide, intervenant essentiellement à l'approche de la transition isotrope-nématique du cristal liquide. Nous discutons de cette nouvelle interaction à la lumière des résultats de nos expériences de diffusion.
La deuxième étude porte sur les émulsions directes eau-cristal liquide en présence de surfactants amphotropes que nous avons synthétisés et caractérisés par RMN. La formulation de ces surfactants visait à renforcer leur localisation exclusive à l'interface eau-cristal liquide. Les émulsions obtenues montrent la formation spectaculaire de gouttes allongées cylindriques de type filaments. Les propriétés statiques et dynamiques de ces objets ont été explorées et l'origine de cette instabilité est explicitée. La longueur des microtubes est modifiable par des gradients de concentration ou des variations de température ce qui nous a permis de discuter du mécanisme régissant leur morphologie.
Simonin, Olivier. "Contribution à la résolution collective de problème (Modèles d'auto-organisation par interactions directes et indirectes dans les SMA réactifs et robotiques)." Habilitation à diriger des recherches, Université Henri Poincaré - Nancy I, 2010. http://tel.archives-ouvertes.fr/tel-00546300.
Zarzoso-Lacoste, Diane. "Vers une meilleure compréhension des interactions trophiques directes et indirectes entre prédateurs invasifs et espèces natives au sein des écosystèmes insulaires." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4330/document.
Introduced predators, particularly cats (Felis silvestris catus) and rats (Rattus spp) are recognized as a major factor of rarefaction and extinction of island bird species. The impact of predation on bird populations is usually assessed through the morphological identification of bird remains in predator diet samples. A review conducted in this thesis highlighted the qualitative and quantitative biases related to the difficulty of detecting and identifying the consumed bird species in predator diet samples. Molecular methods allow the accurate detection and identification of targeted prey DNA in the diet of predators. A large part of the work entailed here has been to optimize the molecular protocol and particularly the key steps of the selection of.taxon-specific primer pairs and the extraction of prey DNA. A comparative study of the performances of both morphological and molecular methods highlighted the strength of the latter in the detection and identification of the bird species preyed by cats and rats on Niau island (French Polynesia). The study of the direct (predation) and indirect (competition for food) trophic interactions between three invasive predators (R. exulans, R. rattus and F. s. catus) and a critically endangered bird, the Tuamotu Kingfisher (Todiramphus gambieiri), demonstrated a very low impact of cats and rats on the population of Tuamotu Kingfisher through predation, but a high potential for food competition between this bird and the two species of rats, particularly for lizards (Scincidae) and some terrestrial arthropods. Finally, management perspectives regarding the conservation of Kingfisher Gambier are proposed and discussed
Daniel, Richard Crosson. "Ink-media interactions in ink-jet printing /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/9829.