Dissertations / Theses on the topic 'Azobenzène – Effets de la lumière'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Azobenzène – Effets de la lumière.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Harvey, Luke. "Elaboration of photo-responsive supramolecular nano-cylinders in solution." Electronic Thesis or Diss., Le Mans, 2023. https://cyberdoc-int.univ-lemans.fr/Theses/2023/2023LEMA1035.pdf.
The aim of this work was to elaborate supramolecular nano-cylinders that may be reversibly disrupted usinglight as a trigger. To this end, Azo-(U-PEO)2 was designed and synthesized. This is a polymer composed of alight-responsive azobenzene bisurea self-assembling core, linked to two poly(ethylene oxide) (PEO) armswith short alkyl chains. As long as the photo-responsive azobenzenes were in their planar trans configuration,this polymer could be self-assembled into nano-cylinders through directional and cooperative hydrogenbonding between urea units.In water, the polymer could be self-assembled into long nano-cylinders of several hundreds of nanometers inlength, by first dissolving it in DMSO, followed by water addition, triggering self-assembly. UV irradiationtriggered photo-isomerizing of the azobenzene units to their non-planar cis configuration, leading to thedisruption of the nano-cylinders. While blue light irradiation did lead to recovery of the initial trans isomer, thiswas not accompanied by the re-assembly of the nano-cylinders. This could be explained by the kineticallyfrozen nature of the assemblies, due to hydrophobic effects.In toluene and chloroform, where there were far fewer solvophobic effects, the polymer self-assembledspontaneously into nano-cylinders, suggesting that the system was at thermodynamic equilibrium. UVirradiation led to partial disassembly in toluene, while it was total in chloroform. Blue light irradiation led tototal re-assembly in toluene, and only partial re-assembly in chloroform.To summarize, the main aim of this project was achieved, and represents the first example of reversible lighttriggereddisassembly of supramolecular polymer decorated nano-cylinders
Fabbri, Filippo. "Déformation photoinduite dans les films minces contenant des dérivés d'azobenzène : effets de polarisation, de proximité et de contact." Palaiseau, Ecole polytechnique, 2009. http://pastel.archives-ouvertes.fr/docs/00/52/73/88/PDF/Thesis.pdf.
In this work we use direct local-probe techniques to study the photomechanical phenomena induced at micro- nanoscale in photochromic thin films containing azobenzene molecules. We show the existence of different mechanisms at the origin of the photo-induced deformation and their crucial dependence on the spatial distribu- tion of the light field polarization and intensity, which allows to coherently interpret far-field and near-field photo- deformation phenomena so far observed. Moreover, we investigate the near-field deformation effects due to the interaction between the local probe and the sample surface. Finally, we present preliminary studies of the photo- mechanical effects in layered hybrid metal/azo-polymer structures which open perspectives in view of applica- tions in the fields of nano-fabrication and nano-actuation of thin films and surfaces
Khoukh, Sihame. "Associations photostimulables entre polymère et tensioactif et application à la concepion d'émlsifiant : contrôle de la stabilité et de l'inversion d'émulsions par la lumière." Paris 6, 2006. http://www.theses.fr/2006PA066534.
Tchénio, Paul. "Transitoires cohérents en lumière incohérente : effets de champ fort." Paris 11, 1989. http://www.theses.fr/1989PA112006.
CHAMAILLARD, KARINE. "Etude statistique des effets de rugosite des grains de poussieres sur leurs proprietes optiques." Cergy-Pontoise, 1999. http://www.theses.fr/1999CERG0081.
Chevallier, Eloïse. "Cascade d'effets induits par la lumière aux interfaces liquides : du photo-surfactant à la mousse." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00828281.
Filippo, Fabbri. "Déformation photoinduite dans les films minces contenant des derivés d'azobenzene: effets de polarization, effets de proximité et effets de contact." Phd thesis, Ecole Polytechnique X, 2009. http://pastel.archives-ouvertes.fr/pastel-00527388.
Bellando, de Castro Louis. "Localisation de la lumière et effets coopératifs dans des nuages d'atomes froids." Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-00988897.
Delteil, Aymeric. "Exaltation multicorps du couplage lumière-matière." Phd thesis, Université Paris-Diderot - Paris VII, 2012. http://tel.archives-ouvertes.fr/tel-00793607.
Shlesinger, Ilan. "Contrôle de l'émission spontanée de lumière par effets collectifs en présence d'un résonateur." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLO006/document.
Spontaneous emission of light is not an intrinsic property of an emitter. On the one hand, it depends on the electromagnetic environment. On the other hand, it depends on the presence of other emitters with whom it may interact and generate interferences. Up to date, very few studies address the question of multiple interacting emitters coupled to a resonator. The goal of this thesis is to combine both collective effects and nanoresonators to control the spontaneous emission and scattering of light emitters.First, we theoretically study an ideal system consisting of two emitters coupled to a resonator. The emitters are in close proximity, and the dipole-dipole interaction generates a superradiant state and a subradiant state. The system that we obtain behaves as an efficient, and tunable, single photon source and quantum memory. We then switch to the case of a plasmonic resonator with an antisymmetric mode, which allows to efficiently excite the subradiant state. We show that this results in an enhancement of the Purcell effect while maintaining a spectrally narrow state.In the second part of this thesis, we explore a system of a large number of emitters coupled to a surface plasmon travelling along a metal-air interface.The emitters are nanoplatelets, also called colloidal quantum wells. Strong coupling is obtained when a layer of nanoplatelets is deposited on top of the metal. The coupling of the nanoplatelets to the surface plasmon allows to obtain directional and polarized light emission
Chevallier, Eloïse. "Cascade d'effets induits par la lumière aux interfaces liquides : du photo-surfactant à la mousse." Phd thesis, Paris 6, 2012. http://www.theses.fr/2012PA066656.
A new system is described here, a photo-foam. A UV stimulus triggers a fast and localized destabilization of such a foam, still quite stable in ambient white light. This photo foam is made of a solution of a photo-surfactant synthesized in the lab. The hydrophobic tail containing an azobenzene group is able to change its conformation reversibly depending on the light stimulus (UV or blue). First the two isomers of the surfactant (cis and trans) are shown to have a very different affinity to the air-water interface. Second, this work establishes that the light stimulus generates a flux of desorption of the surfactant from the interface. This molecular flux triggers a series of effects at different scales of the foam : 1. At an air-water interface, light controls the adsorption of the surfactant so that surface tension can be finely tuned by the light intensity. 2. For a soap film, electrostatic interactions are modified in few seconds. Thus, the initial thickness of the film becomes instable and various objects are thus created. 3. When soap thick films are interconnected, Marangoni flows are developed and can prevent the drainage to occur. Their dynamics is directly determined by the molecular desorption flux, and controlled by light intensity. 4. The study of these different fluxes at different lengthscales brings a new perspective to understand the fast destabilization of the photo-foam, but also its local drainage retardation
Kachaya, Mona. "Amas d'argent induit dans des films minces de chlorure d'argent par implantation ionique et illumination : formation et stabilité." Lyon 1, 1986. http://www.theses.fr/1986LYO10069.
Abidi, Farouk. "Effets de la qualité de la lumière sur l'élaboration de l'architecture du rosier buisson." Angers, 2013. http://tel.archives-ouvertes.fr/tel-00871779.
The global shape of an ornamental plant is one of its major aesthetic criteria. It is controled by its architecture, particularly by bud bursting and shoot elongation. Environmental factors including light have a strong impact on both processes. The management of the lighting conditions during plant culture could help to produce plants with innovative shapes, using environmentally-friendly practices. However, there is a significant lack of knowledge about the mechanisms involved in the regulation of plant development by light. In this thesis, we studied the effect of blue light on the architectural development of two varieties of rose bushes coupling morphological, histological and molecular approaches. Our results show that monochromatic blue light has a depressive effect on the photosynthetic assimilation of roses but induces in both cultivars, same meristem organogenetic activity, internodes growth and floral development than full spectrum light. On the contrary, the removal of blue raies from white light stimulates the elongation of the first order axis in one of the two studied cultivars. This stimulation results from the increase of leaf photosynthetic assimilation and internode cell elongation. This photo-control is exerted on the expression of genes involved in sugar metabolism and cell wall loosening. Our study of photoreceptor mutants in pea suggests that phytochrome B is the major photoreceptor involved in this response to blue light
Xu, Yong. "Étude des effets de la lumière sur les propriétés électriques d’une jonction tunnel magnétique." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0256/document.
This thesis is devoted to the study of the effects of light on a magnetic tunnel junction (MTJ). A MTJ is made of a nanometer thick insulating layer sandwiched between the two magnetic layers. When an electric current is injected into such a structure, a voltage can be measured across the insulating layer. This voltage depends on the relative orientation of the magnetizations of the two magnetic layers. This is known as the tunnel magneto-resistance effect. We have shown in this thesis that voltage depending on the orientation of the magnetic layers can be measured when the junction is illuminated with light. By studying the influence of the substrate, the position of the light beam, the wave length of light and the response of the system to a laser pulse, we have been able to demonstrate the presence of photovoltaic and Seebeck effects. These results show that it is possible, thanks to the sunlight, to read the information from magnetic memory (MRAM) made of a MTJ
Rouabah, Mohamed Taha. "Effets de cohérence en diffusion multiple de la lumière et intrication des états cohérents." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4012/document.
This work is devoted on the one hand to the investigation of coherence effects in multiple scattering of light by an atomic cloud and on the other hand to the entanglement of a deformed coherent state. The interaction between light and a dilute disordered atomic cloud gives rise to collective coherent effects due to the interaction of the induced dipoles via the external field. The behavior of such coherent effects in multiple scattering regime is an important question for various physical systems. We present two theoretical models describing those coherence effects in different scattering regimes. The scattering order expansion treatment of light scattering allows us to highlight the role of the first and second scattering orders as well as the interference between the resulting scattered fields. In the multiple scattering regime we show that the radiation pressure force is not a good observable to probe cooperative effects. Furthermore, we discover a surprising phase coherence that hints that collective effects may survive in multiple scattering regime. That could be due to a synchronization between the induced atomic dipoles. In a second part, we study the effect of an algebra deformation on entangled coherent states. Such an approach allows to describe decoherence in perturbed entangled quantum systems. We construct a deformed coherent state and calculate their concurrence. We show that algebra deformation could have a non negligible impact on bipartite entangled coherent states if those later are not maximally entangled
Chehadi, Zeinab. "Nanostructures hybrides Au/Semi-conducteur : investigation des effets plasmoniques en catalyse sous lumière visible." Thesis, Troyes, 2017. http://www.theses.fr/2017TROY0016/document.
The excitation of Localized Surface Plasmon Resonance (LSPR) of Gold NanoParticles (GNPs) can give many physical effects such as near-field enhancement, heat generation and hot electron injection, which have been investigated in many chemical transformations. In that context, the plasmonic photocatalysis based on electron transfer from GNP to a semi-conductor has been proposed. However, few studies are focused on the influence of LSPR features and the respective contribution of its local effects (thermal and electronic) on the photocatalytic activity. These issues are addressed herein through 3 catalytic reactions. First, the efficient and selective oxidation of glycerol in the presence of supported GNPs is demonstrated under laser irradiation and without any external source of heat, thanks to the local heat generation and hot electron transfer. The respective contributions of these effects is further investigated in plasmonic photocatalysis by following the degradation of Bisphenol-A. Our results show that GNP plays a major role through hot electron transfer but also as a nano-source of heat that accelerates the reaction and leads to a fast and total elimination of this endocrine disruptor. Finally, an optical set-up is developed for studying the plasmonic photocatalysis at the nanoscale. For this, a hybrid system of GNPs coupled to a TiO2 nanofilm is realized by laser nanostructuring. Our investigations show that photocatalytic activity is correlated to the LSPR (size and shape of GNPs, hot spots). These results open the way for exploiting valuable and industrial reactions under solar light
Verlot, Pierre. "Etude des effets de pression de radiation et des limites quantiques du couplage optomécanique." Paris 6, 2010. http://www.theses.fr/2010PA066343.
Berthier, Alexandre. "Transport du saccharose chez le Ray-grass anglais (Lolium perenne L. ) : réponse à la défoliation et à l’intensité lumineuse : Thèse soutenue sur un ensemble de travaux." Caen, 2011. http://www.theses.fr/2011CAEN2001.
We wanted to determine the nature of sucrose transport, isolate, characterize and localize one or more sucrose transporters (SUTs) and assess if these SUTs respond to defoliation or to a modulation of light intensity before and/or after defoliation in rye-grass. Sucrose transport is apoplastic. It depends on a multigenic family of SUTs that were identified for the first time in rye-grass (LpSUT1, LpSUT2). The functional characterization of LpSUT2, which possess a cytoplasmic inner loop, was also successfully realized for the first time in a Monocot species. LpSUT2 is inhibited by fructose, which is a remarkable result for a fructan-accumulating plant, thus suggesting that this SUT could be the perception site of a sugar signal. The expression and the localization of these SUTs, mainly in the mesophyll, suggest that they play a great role for the distribution of C resources within the regrowing plant. The LpSUT1transcript level increases in the few hours following defoliation and might be regulated by sucrose content. LpSUT1 could be implicated in the lateral sucrose transport associated to the storage and/or the mobilization of fructans. The LpSUT2 transcripts are not sensitive to defoliation, but they are surprisingly modulated by light intensity before and/or after defoliation, which could strikingly match their putative role of sugar sensors. Because neither LpSUT1 nor LpSUT2 are localized within phloem tissues, this suggest the existence of other SUTs. The present results allow to better understand regrowth mechanism within a perennial forage species accumulating fructans
Ibrahim, Tharwat. "Dendrologie et fonctionnement hydrique de jeunes plants forestiers en relation avec la lumière et la sécheresse édaphique." Nancy 1, 2006. http://www.theses.fr/2006NAN10094.
This work had as first objective the analysis of water relations of five forest species (Fagus sylvatica, Betula verrucosa, Quercus petraea, Quercus péd onculé et acer pseudoplatanus) in relation with the irradiance. We used a conductmetre (the hydraulic methods) to measure the loss of the conductivity PLC in the side-branches (2years) for these different species. Clear differences observed between species and treatments. This gradient is strongly correlated with irradiance that branches received during the growth. Vulnerability curves for the four studied species are presented figure. We noticed a higher vulnerability for birch. The shape of the curves for the other species were very close. In each case, seedlings grown under shade presented an higher vulnerability than full light. Differences were highly significant. Differences between Psi 50% for extreme treatments (full light and deep shade) could reach 1 MPa. Xylem anatomy presents for all the studied species a high dependence with irradiance. The Oak presented the largest vessels and the weakest vessel densities globally. The impact of the luminous climate was very clean, with a gradual reduction of the diameter and the density of vessels in weak light with a clean reduction of the diameter and the density of vessels in all species. . . .
Paillard, Charles. "Effets photo-induits dans les multiferroïques." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC055/document.
The need for clean and renewable energy, as well as constantly improved numerical performances have been two of the most important driving forces in research worldwide. In this light, multiferroic materials, which are materials presenting several ferroic order, have been widely investigated towards their application in electronics and computation, or as sensors. Recently, they have been also considered for their potential use to generate energy through the photovoltaic effect. However, power conversion have remained poor compared to existing technologies such as p-n junction silicon based solar cells, mainly because of their wide bandgap and low mobility of the carriers. Nevertheless, multiferroic materials often present a vast number of degrees of freedom, and their interaction with light cannot be reduced to the sole photovoltaic effect.In this work, we study from first-principles the interaction of light and strain in the multiferroic bismuth ferrite, and find that the so-called photostriction effect originates from a screening of the polarization at the unit cell scale, which results in a photo-induced strain via the action of the converse piezoelectric effect. A solid solution of lead nickel niobium and lead titanate, exhibiting large electromechanical properties at its morphotropic phase boundary, is then synthesized, and its optical and photoinduced properties are studied. Also, the influence of defects at domain walls in the model ferroelectric lead titanate is studied from ab-initio calculations, in order to understand why domain walls exhibit a large conductivity compared to the domains. It is found that defects are more likely to form at the domain wall, and provide it with extra-carriers. Eventually, the advances in a recently considered spin-orbit energy term, the Angular MagnetoElectric coupling (AME), are considered and applied to the Inverse Faraday Effect (IFE), that is the existence of a magnetic field induced by circularly polarized light
Briant, Tristan. "Caractérisation du couplage optomécanique entre la lumière et un miroir : bruit thermique et effets quantiques." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2003. http://tel.archives-ouvertes.fr/tel-00004972.
Nous avons mesuré le bruit thermique du miroir et suivi son évolution temporelle dans l'espace des phases. Nous avons refroidi le miroir en exerçant une force de friction froide et obtenu une compression du bruit thermique dans l'espace des phases.
Une étude spatiale des modes acoustiques internes a été réalisée pour différentes géométries du miroir, en balayant une force de pression de radiation sur la surface du miroir. Les résultats valident les modèles théoriques utilisés pour les interféromètres gravitationnels et permet de définir une géométrie favorable à la démonstration des effets quantiques du couplage optomécanique.
Nous présentons également une étude théorique des bruits thermiques et quantiques dans un nouveau type d'antenne gravitationnelle, constituée de deux sphères imbriquées.
Askenazi, Benjamin. "Du couplage ultra-fort lumière-matière : nouvelle Ingénierie de Métamatériaux Térahertz." Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCC127.
Sub-wavelength patterning of one or several materials can give rire to "metamaterials", with artificial electromagnetic properties. This work is focused on the design and realization of THz metamaterials, exploiting plasmonic cavity engineering and many-body effects in a dense electron gas. In the first part of this manuscript, many-body effects are investigated through the optical response of an electron gas in a semiconductor layer. The electron gas displays a cooperative response to an incident electromagnetic field : its absorption spectrum shows a unique sharp resonance, centred at an energy that depends on the electronic density and on the confinement. A model is presented that describes infrared absorption of thin doped semiconductor layers as well as intersubband absorption in a quantum well. When a highly doped semiconductor layer is inserted in a metallic microcavity, the so called "ultra-strong" coupling regime is achieved between the electronic many-body excitation and the cavity fundamental optical mode. Through an optimization of the cavity geometry, I demonstrate a record value of the relative coupling strength at room temperature. The ultra-strong coupling regime is then used for two different applications: a metamaterial with an artificial photonic reflectivity band and a cavity with an extremely high effective index. Those cavities are then used to realize an incandescent THz source, operating at room temperature
Massier, Sébastien. "Effets du traitement par la Lumière Pulsée sur la physiologie de Pseudomonas aeruginosa et d'Enterococcus faecalis." Rouen, 2011. http://www.theses.fr/2011ROUES030.
This work is devoted to the study of the bacterial response of Pseudomonas and Enterococcus genus against Pulsed Light treatment (PL). First, the characterization of the PL decontamination unit has chosen a configuration for achieving uniform treatment and to know the physical characteristics. On the other hand, very rapid kinetics destructions of bacterial cultures are obtained in this configuration (reduction of 9 logarithm units a few seconds). In this study, we showed that Pseudomonas aeruginosa is usually more sensitive than Enterococcus faecalis with respect to the same intensity treatment. However and interestingly Pseudomonas aeruginosa is able to adapt to a lethal treatment LP when subjected to sublethal PL doses. While Enterococcus faecalis showed a mutation rate increased after treatment. These different mechanisms used by bacteria in order to cope with the deleterious PL effects were identified by two-dimensional electrophoresis analysis to elucidate the molecular mechanisms involved in these responses
Obeid, Nada. "Régime juridique du divorce : causes et conséquences, réforme du droit libanais à la lumière du droit français." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1G012.
Lebanon is known for its original and specific system relevant to its history and the Lebanese society is a pluralistic society made up of different communities, each having its own traditions, beliefs and organization. This pluralism permeates the various structures of the State, based on the balance of representation of communities. It also reflects on its legal system, which seeks to preserve the communities’ identities, mainly in matters of personal status where the traditional powers of the religious authorities are recognized by the State and ensured by civil effectiveness. However, religious pluralism and the prevalence of the religious in terms of civil status are considered "as an anachronism, as a brake retarding the growth of the State and the realization of the unity of the Nation". Thus, for the same cause and for the same reasons, the inhabitants of the same country, Lebanon, are judged differently, and sometimes in a contradictory manner as well, for the sole fact that they belong to such a religion and not to another. In marriage law, divorce, for the same reasons, may be legitimately granted to some and legitimately denied to others. Moreover, "based on truths often revealed, religious rights would be incapable of conveying the reforms that modern society calls for", in particular the liberalization of the right of divorce which explicitly retains only divorce-sanction and implicitly divorce-remedy due to illness only. The confrontation of the family rights of the divorce - Lebanese and French - will make it possible to highlight the differences which oppose them and the principles that underlie them and to see in what sense and to what extent a reform of the Lebanese law of the divorce is possible in the light of the French law of divorce, the civil law which has liberalized the conception of divorce
Rousselet-Perraut, Karine. "Modélisation des effets de polarisation dans un interféromètre stellaire : application aux observations astronomiques haute résolution angulaire en lumière polarisée." Aix-Marseille 3, 1996. http://www.theses.fr/1996AIX30034.
Arthaut, Louis-David. "Effets de la lumière bleue et du champ magnétique sur la synthèse des ROS par le cryptochrome." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS400.
Cryptochromes are photoreceptors that absorb blue light, they are found in animals and plants and have multiple signaling roles. In plants they can regulate growth, development, circadian rhythms or stress; in animals they also regulate circadian rhythms and stress responses. Their activation in the presence of blue light is reflected biochemically by the photoreduction of the flavin which is associated with these proteins, this cofactor then triggers a conformational change of the C-terminus domain that will allow the binding of cryptochromes to multiple partners responsible for signaling. Today, research on the functioning of cryptochromes is based on new fields of study, among them are their link with the ROS and their sensitivity to magnetic fields. In our work we show for the first time that animal cryptochromes can also directly synthesize some ROS after activation in blue light, and that this synthesis which is also observed in plants has a signaling role. Finally, we have linked their magnetoreception property with their ROS synthesis in animal cell models
Cottier, Florent. "Interaction lumière-atomes : approche de champ moyen et fluctuations d’intensité." Thesis, Université Côte d'Azur (ComUE), 2019. http://www.theses.fr/2019AZUR4024/document.
In this thesis, we investigate the coherent scattering of light propagating in a random medium. We are interested in phenomena like the super- and subradiance and Anderson localization that are related to waves interferences and spatial disorder. However, the fundamental difference between subradiance and Anderson localization still needs to be clarified. This thesis gives new elements for the understanding of these phenomena and we present a new method to observe Anderson localization. A mean-field model that does not contain disorder is developed, and we show that super- and subradiance do not require disorder whereas Anderson localization does. In this theoretical work, the coupling between the light and many atoms is reduced to a coupling matrix between the atoms by tracing over the degrees of freedom of the light, which results in a linear problem for the atomic dipoles. The study of the eigenvalues and eigenmodes of this matrix then allows to determine the super- and subradiant modes, and to probe the Anderson localization phase transition with a scaling analysis. Furthermore, the link to the experiment is realized by showing that the intensity fluctuations present an increase at the localization transition. The system is studied in the steady-state regime when the medium is continuously charged by a laser until reaches a stationary regime, and the decay dynamics, when the laser is switched off, so the cloud releases the energy stored. Finally, we present a preliminary work that shows that the diagonal disorder might be a good strategy to reach Anderson localization
Boivin, Catherine. "Effet de l'intensité lumineuse sur le contrôle de la reproduction chez la brebis et sur la croissance des agneaux." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24666/24666.pdf.
Lachance, Marie-Pier. "Impact d'une photopériode prolongée en maternité sur les performances et le comportement des truies et des porcelets." Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27193/27193.pdf.
Martinet, Quentin. "Étude des effets environnementaux sur les modes acoustiques confinés de nanoparticules par diffusion inélastique de la lumière." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1152/document.
Over the past twenty years, inelastic light scattering by vibrational eigenmodes of nanoparticles, called Lamb modes, has proven to be an effective method for characterizing the size and mechanical properties of nano-objects. The resonant frequency of a nano-sphere, in the gigahertz range, is given, as a first approximation, by the ratio of the acoustic velocity of the bulk material and the size of confinement. The refinements of the theoretical model allow to obtain, from these eigenmodes, information on the shape and local environment of nano-objects.The objective of this thesis is to probe the domain of validity of the Lamb model, to analyze the different impacts of the environment on eigenmodes and to develop a new strategy to measure them. Several aspects of interaction with the external medium can be considered depending on the system studied. On the one hand, the delocalization of the acoustic wave in the case of core shell systems is ruled by the acoustic impedance of the core and the shell and leads to a mechanical coupling. On the other hand, the inertial mass effect induced by the presence of organic ligands on the surface of the particle modifies the resonant frequency. The validity of both approaches is discussed according to the configuration and these models are applied to real cases, such as semiconductor core shell nanoparticles and nanoplatelets, or gold colloidal clusters. The inertial mass effect is significant for small objects and it is shown the feasibility to realize ultra-sensitive nano-balance capable of probing the local environment of nano-objects. Furthermore, in the case of gold clusters, this approach makes it possible to discuss the limit of the Lamb model, based on continuum mechanics, to interpret vibrations involving only six atoms. Thanks to low frequency Raman spectroscopy, it appears that the experimental results are in good agreement with both the continuum mechanics approach, by considering the inertial mass effect, and also with density functional theory (DFT) calculations. Finally, the experimental development of an optical set-up capable of measuring low frequency Raman modes on a single nanoparticle in a liquid medium is presented. This technic requires to localize a nanoparticle in a liquid medium with plasmonic tweezers and to enhance the low frequency Raman signal by stimulating vibrational modes with electrostriction. The perspectives are to apply this method to the dynamical study of a single object such as viruses or proteins
Martinot-Lagarde, Gregoire. "Effets mécaniques de la lumière sur des sphères de polystyrène dans l'eau : mesure et applications physico-chimiques." Bordeaux 1, 1995. http://www.theses.fr/1995BOR10595.
Kojadinovic, Mila. "Effets antagonistes de l'oxygène et de la lumière sur la régulation de la photosynthèse et de la respiration chez Rhodopseudomonas palustris." Aix-Marseille 2, 2007. http://theses.univ-amu.fr.lama.univ-amu.fr/2007AIX22041.pdf.
The photosynthetic purple bacterium Rhodopseudomonas palustris is able to develop using photosynthesis or respiration. Extraordinarily, it possesses six bacteriophytochromes and two PpsR transcriptional regulators. This work aimed at studying bacteriophytochromes and PpsR roles in the regulation of photosynthesis and respiration by light and oxygen. The study of photosystem synthesis and respiratory activity in Rps. Palustris WT, or inactivated in bacteriophytochromes or in PpsRs showed that (i) the bacteriophytochrome RpBphP1, activated by a far red illumination can trigger photosystem synthesis, by counterbalancing PpsR2 repressive effect, from microaerobic to aerobic conditions ; (ii) that LH2 antennae synthesis is activated by the PpsR1 transcriptional regulator and the bacteriophytochrome RpBphP4, which, depending on the Rps. Palustris strain, can be an oxygen sensor or a light sensor and (iii) that RpBphP1, PpsR1 and PpsR2 are involved in the regulation of Rps. Palustris respiratory activity by far red light. Considering the results obtained combining in silico, molecular biology and biochemistry approaches, we propose that the bacteriophytochrome RpBphP1, by inhibiting PpsR2 activation on the transcription of sucA – encoding the subunit E1 of the alpha-ketoglutarate dehydrogenase, a central enzyme in the Krebs cycle – is responsible for a 40% respiration limitation under far red illumination relative to darkness. Our results showed that a far red illumination, via RpBphP1 action on PpsR2, has a double effect since it activates photosystem synthesis on the one hand, and limits respiration on the other hand. This work also revealed that PpsR1 and PpsR2 regulators are both transcriptional repressors and activators, which can have joint or opposite effects. Finally, we showed that the molecular mechanisms responsible for the metabolic regulations encountered in Rps. Palustris are not all retrieved in the phylogenetically closely related bacterium, Bradyrhizobium ORS278
Laffort, Brigitte. "Orientation spatiale et lumière polarisée chez Talitrus saltator (Crustacea, Amphipoda) aspects comportementaux et évolutifs." Toulouse 3, 1992. http://www.theses.fr/1992TOU30104.
Courties, Alicia. "Les effets de la lumière sur le métabolisme du carbone des bactéries marines contenant la protéorhodopsine : cas d’étude en culture continue d’une Gammaprotéobactérie Photobacterium angustum S14." Paris 6, 2013. http://www.theses.fr/2013PA066672.
Since its discovery more than 10 years ago, there are more and more studies about proteorhodopsin. This protein seems to be significant in marine ecology considering its large global distribution among many bacterial taxa; but its role remains controversial. Although light response from proteorhodopsin-containing prokaryotes (PCPs) seems to be strain-dependent, it has been hypothesized that the main function of proteorhodopsin was to provide an advantage to PCPs during starvation conditions. In this work, we investigated the increase knowledge about the role of proteorhodopsin regarding the organic carbon utilization efficiency measured in the proteorhodopsin-containing Gammaproteobacterium (Photobacterium angustum S14) in the light compared to the dark. Carbon-limited continuous cultures have been used to mimic environmental conditions. Yields and energetic maintenance were determined according to Pirt’s model (1965) with acid pH or without supplementary pH-stress. We observed highest energetic maintenance in the dark under pH stress condition. However, when light-dark cycles were used, the energy required for bacterial maintenance was significantly decreased during all the run and nearly in the range without pH stress. Taking together, it seems that the response of P. Angustum S14 to light is more linked to the energetic balance than substrate concentration. The innovative results indicate a possible reason why many studies did not observe positive effects on bacterial growth and yield. In addition, PCP sequencing was performed to confirm these conclusions at a more large taxa scale
Briand, Decré Gwenaëlle. "L’influence des stimuli lumière et température sur les réponses émotionnelles et conatives des consommateurs au sein du point de vente." Paris 9, 2011. https://portail.bu.dauphine.fr/fileviewer/index.php?doc=2011PA090012.
While the influence of lighting and temperature on consumer behavior in retail outlets is of conceptual and managerial importance, they are understudied aspects of store environment. Based on a multidisciplinary literature (social psychology, psychiatry, ergonomics, medicine) and on Stimulus-Organism-Response models, our research aims at studying (1) the effect of these stimuli on affective and behavioral responses in retail outlets, (2) and the effect of uncomfortable levels of temperature as well. The moderating effects of season, optimal stimulation level and gender have been studied. From this perspective, two experiments have been conducted, one with digitally manipulated pictures and one in laboratory. The findings of the two experiments are convergent considering the main hypotheses and the influence of key variables. Managerial and conceptual implications are discussed
Mihiretie, Besira. "Effets mécaniques de la lumière sur des particules anisotropes micrométriques et dynamique du mouillage à l'interface eau-air." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00869331.
Roco, Fossa Rodrigo. "Les effets de pairs à la lumière des interactions entre élèves et des dimensions subjectives du vécu scolaire." Phd thesis, Université de Bourgogne, 2011. http://tel.archives-ouvertes.fr/tel-00665829.
Mihiretie, Besira. "Effets mécaniques de la lumière sur des particules anisotropes micrométriques et dynamique du mouillage à l’interface eau-air." Thesis, Bordeaux 1, 2013. http://www.theses.fr/2013BOR14813/document.
We report experiments on ellipsoidal micrometre-sized polystyrene particles. The particle aspect ratio (k) varies between about 0.2 and 8. These particles are manipulated in water by means of a moderately focused laser beam. We observe the levitation and the dynamical state of each particle in the laser beam, in bulk water or in contact to an interface (water-glass, water-air, water-oil). In the first part, we show that moderate-k particles are radially trapped with their long axis lying parallel to the beam. Conversely, elongated (k>3) or flattened (k<0.3) ellipsoids never come to rest, and permanently “dance” around the beam, through coupled translation-rotation motions. The dynamics are periodic or irregular (akin to chaos) depending on the particle type and beam characteristics. We propose a 2d model that indeed predicts the bifurcation between static and oscillating states. In the second part, we apply optical levitation to study the transition from total to partial wetting of the particles at the water-air interface. We show that the dynamics of the transition is about independent of particle shape, and mainly governed by the pinning-depinning mechanism of the contact line
Morin, Philippe. "Nouveaux systèmes de contrôle de la polarisation de la lumière par effets non lineaires dans les fibres optiques." Phd thesis, Université de Bourgogne, 2013. http://tel.archives-ouvertes.fr/tel-00956783.
Maure, Sophie. "Effets d'interface et de volume dans le processus des pertes optiques dans les structures planaires multicouches : application à la diffision piégée et aux cavités luminescentes." Aix-Marseille 3, 1996. http://www.theses.fr/1996AIX30093.
Abidi, Farouk. "EFFETS DE LA QUALITE DE LA LUMIERE SUR L'ELABORATION DE L'ARCHITECTURE DU ROSIER BUISSON." Phd thesis, Université d'Angers, 2013. http://tel.archives-ouvertes.fr/tel-00871779.
Marquestaut, Nicolas. "Effets d'exaltations par des nanostructures métalliques : application à la microscopie Raman en Champ Proche." Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13812/document.
This thesis work focuses on Raman scattering enhancements by metallic nanostructures. In the first part of this work, arrays of metallic patterns with nanometer dimensions were fabricated by the Langmuir-Blodgett deposition technique and electron-beam lithography. Such structures made of gold were fabricated onto microscope slides with the goal to enhance the Raman signal through SERS effect (Surface Enhanced Raman Spectroscopy). These patterns formed by an assembly of triangular nanostructures with sizes of hundreds of nanometers, exhibit plasmon resonance bands in the visible spectral region. By using an appropriate excitation laser source with respect to the plasmon frequency, Raman enhancement factors of a monolayer were found to be of several order of magnitude for both Langmuir-Blodgett and electron-beam lithography platforms. To further complement these results, gold wires arrays with large aspect ratio made by electron-beam lithography showed multipolar plasmon resonances with enhancement factors up to 105. In the second part of this thesis, near-field Raman microscopy has been developed with the aim to localize precisely the Raman enhancement and improve spatial resolution of Raman measurements. Atomic force microscopy gold tips have been used to locally enhance scattering signal of molecules in close proximity to the tip opening new opportunities. This approach known as TERS (Tip Enhanced Raman Spectroscopy) is of significant interest to probe nanomaterials, nanostructures or monolayers. Software and mechanical developments have been made between a confocal Raman microscope and an atomic force microscope to control simultaneously both instruments. This experimental setup was used to characterize gallium nitride semi-conductors nanowires with spatial resolution better than 200 nm
Gagné, Anne-Marie. "Modulation de la réponse rétinienne par l'histoire lumineuse récente ou la mélatonine chez le sujet sain ou affecté du trouble affectif saisonnier." Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27144/27144.pdf.
Gagné, Marielle. "Impact de la lumière sur la production de protéines recombinantes chez Nicotiana benthamiana." Master's thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/26977.
La moléculture végétale est une approche prometteuse pour la production de protéines d’intérêt médical ou industriel. Considérant les variations de rendement possibles dans une plante soumise à différentes conditions culturales, nos objectifs étaient : (i) de cartographier l’accumulation d’un antigène viral d’intérêt clinique dans les feuilles du tabac sauvage Nicotiana benthamiana utilisé comme bio-usine, et (ii) d’évaluer l’impact de la lumière en période de croissance sur le rendement total en antigène. Nous avons étudié les relations entre l’âge foliaire, le régime lumineux, l’expression du transgène et le rendement final en antigène dans les feuilles. Nos données confirment l’influence de l’âge sur les variations de rendement d’une feuille à l’autre, et l’impact positif de l’intensité lumineuse sur le rendement par plante. Elles mettent aussi en relief l’importance des tiges secondaires sur le rendement et le rôle clé de la transcription du transgène sur la teneur en antigène à l’échelle cellulaire.
Plant molecular farming is a promising approach to produce proteins of medical or industrial interest. Considering possible variations of protein yield in plants exposed to different cultural conditions, our goals were : (i) to map the accumulation of a clinically useful viral antigen in leaves of the tobacco relative Nicotiana benthamiana used as protein biofactory, and (ii) to evaluate the impact of light conditions during plant growth on total antigen yield. We looked at eventual relations in planta between leaf age, light intensity, light quality, transgene expression and final protein yield in leaves. Our data confirmed the central influence of leaf age on antigen yield variation from one leaf to another, and the positive impact of light intensity on total yield per plant. They also highlight the importance of secondary stem growth on total yield, and the key role of transgene transcription on antigen content at the cell scale.
Arsenault, Hélène. "EFFETS DU VERRE TEINTÉ SUR LA QUALITÉ DE LA LUMIÈRE NATURELLE, L'ÉVEIL DES OCCUPANTS ET L'UTILISATION D'UN ÉCLAIRAGE D'APPOINT." Thesis, Université Laval, 2012. http://www.theses.ulaval.ca/2012/29060/29060.pdf.
The impact on daylight quality perception, of three windows of similar visual transmittance but different colour (blue, neutral, bronze) was investigated. Participants (n=36, mean age 23.8 years) were seated with their upper body immersed in a scale model (1:4) replicating an office room composed of four walls and a changeable window (blue, neutral or bronze) oriented towards the south-east direction. On separate sessions (one for each window glazing), participants were asked to evaluate the luminous conditions in the room according to the following qualitative factors: visual comfort; naturality; pleasantness; precision (of details and textures); light level. Participants were also asked to evaluate their level of arousal using a sleepiness scale (KSS) at the beginning and end of each session. Mixed model analyses revealed statistically significant higher scores for the factors pleasantness (p=0,003 and p=0,017 when results from the oral and written questions were combined), comfort (p=0,015) and daylight quality (p=0,044) for the bronze window glazing compared to the blue and neutral glazing. The neutral glazing was also preferred over blue for pleasantness (p=0,021). Paired t-test analysis from the KSS results indicated a slight decrease in the level of arousal in presence of the blue glazing. Overall, the thesis shows that there appears to be a clear preference for ambient light filtered through bronze window glazing compared to blue window glazing.
Boulanger, Félix. "La régénération de l'épinette noire en forêt boréale en présence du Kalmia angustifolia étude des effets de la lumière." Mémoire, Université de Sherbrooke, 2005. http://savoirs.usherbrooke.ca/handle/11143/4617.
Caron, Jérôme. "Diffusion de la lumière dans les milieux stratifiés : prise en compte des interfaces rugueuses et des effets de polarisation." Paris 6, 2003. http://www.theses.fr/2003PA066043.
Laviale, Martin. "Effet des polluants sur les communautés périphytiques naturelles : apport des mesures de fluorescence chlorophyllienne en lumière modulée (PAM)." Thesis, Lille 1, 2008. http://www.theses.fr/2008LIL10055.
Ln the context of the European Water Framework Directive implementation, new tools for river toxicity assessment have to be developed. Periphytic communities, which play a fundamental role in the trophic web in lotic systems, could be regarded as early wamings for detection of acute toxicant exposure by monitoring its physiological state. Several studies were then carried out by means of the chlorophyll fluorescence measurement in modulated light technique (P AM fluorescence) which helps to estimate the photosynthetic activity in a non-intrusive way. The aim of the present work was to study the effects of several pollutants commonly found in aquatic ecosystems (Cu, Zn, Cd, atrazine, isoproturon) on stream periphyton physiology and to highlight the role of light as an addition al potentially stressful parameter. Our results showed a relative resistance of the natural biofilms to the pollutants on a short term scale (< 1 day) which depended both on the mechanism of action of the toxicant (herbicides vs heavy metals) and the biofilms architecture. By combining novel experimental designs both in field and laboratory conditions, we also demonstrated that periphyton can be more affected when another stress, such as light, is applied. This work confmns the usefulness of chlorophyll fluorescence-based methods in ecotoxicological studies, particularly in order to detect in situ herbicide toxic effects
Bourgain, Ronan. "Diffusion de la lumière dans les nuages denses mésoscopiques d'atomes froids." Phd thesis, Palaiseau, Institut d'optique théorique et appliquée, 2014. http://tel.archives-ouvertes.fr/tel-00978177.
Erramli, Abdellah. "Etude du chrome et du nickel dans GAP par spectroscopie d'absorption détectée thermiquement." Clermont-Ferrand 2, 1990. http://www.theses.fr/1990CLF21221.