Academic literature on the topic 'Effet enclume'
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Journal articles on the topic "Effet enclume"
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Li, Zhi, Ruyi Yan, Zuo Zhang, and Huaping Sun. "The Effect of Enclave Adjustment on the Urban Energy Intensity in China: Evidence from Wuhan." Sustainability 13, no. 4 (2021): 1940. http://dx.doi.org/10.3390/su13041940.
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Due to the needs of China’s rapid urbanization, enclave adjustments between districts in a city have become a national phenomenon in recent decades. However, it is rarely discussed in the literature whether this adjustment can have an impact on urban energy intensity. Taking Wuhan’s enclave adjustment in 2009 as a sample and a city-level panel dataset during the period of 2005–2014, using the synthetic control method, this paper investigates for the first time the impact of enclave adjustment between districts on the urban energy intensity. The results show that the logarithmic energy intensity paths of real and synthetic Wuhan diverge after 2009, and the enclave adjustment is indeed conducive to reducing energy intensity. Although this policy effect fluctuated slightly in 2013, it remained evident and continued to expand in subsequent years. We also further adopt the permutation test and placebo test to check the robustness of the baseline results, and this policy effect was found to still be statistically significant and persistent over time. We further verified that aligning division management, changing the incentives of local officials, promoting the agglomeration effect, and regional integration after adjustment are potential contributors to reducing urban energy intensity.
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Du, Gai Hong, and Yang Meng Tian. "The Coupling Effect of Electromagnetic Pulse and Computer." Applied Mechanics and Materials 541-542 (March 2014): 452–57. http://dx.doi.org/10.4028/www.scientific.net/amm.541-542.452.
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Coupling characteristic of EM pulse into the computer enclose with aperture and the coupling effect of electromagnetic pulse and computer box are studied. The impact of coupling characteristic of EM pulse into the computer enclose with aperture includes the three aspects (1) the effect of hole shape on the coupling characteristics (2) the effects of the apertures area on the coupling property characteristics (3) the effects of the polarization direction of the electromagnetic pulse on the coupling characteristics; The brief overview of electromagnetic pulse coupling phenomena on the computer includes the following three aspects (1) the physical model of the computer chassis (2) the coupling coefficient of electric field in the computer box and the computer center (3) the change characteristics of the electromagnetic pulse in the computer box; Finally we discussing the preventive approach of computers electromagnetic coupling is.
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Gibbs, P. E. "A Male genital defect in the dog-whelk, Nucella lapillus (Neogastropoda), favouring survival in a TBT-polluted area." Journal of the Marine Biological Association of the United Kingdom 73, no. 3 (1993): 667–78. http://dx.doi.org/10.1017/s0025315400033208.
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Tributyltin (TBT) pollution has exterminated populations of the dog-whelk Nucella lapillus along most of the north Kent coast (Thames Estuary) but the species survives as a small enclave around the North Foreland. Males in this enclave exhibit an unusual defect involving the non-development or partial development of the genital system: about 10% lack penes, or have undersized penes, and their gonoducts (vas deferens and prostate) are incompletely developed; in some cases, spermatogenesis appears to be retarded. Laboratory-bred animals display the same characters. This deficiency (‘Dumpton Syndrome’) is manifest also in the atypical development of male sex organs on the females (‘imposex’) induced by exposure to tributyltin (TBT). The evidence points to Dumpton Syndrome being a genetic disorder which has lessened the sterilizing effect of imposex and thereby has permitted the survival of this isolated enclave in an area of high TBT pollution.
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Le, Anh T. "The Determinants of Immigrant Self-Employment in Australia." International Migration Review 34, no. 1 (2000): 183–214. http://dx.doi.org/10.1177/019791830003400108.
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This article applies both single cross-section and dual cross-section approaches to modeling the propensity to be self-employed among the foreign born in the Australian labor market. The results from a single cross-section regression indicate that educational attainment, Australian labor market experience, the availability of capital, marital status and job related characteristics are important influences on self-employment outcomes. The propensity to be self-employed among immigrants is shown to be enhanced by the existence of enclave markets. Ethnic enclaves created via a common language provide more relevant prospects for self-employment than does the concentration of immigrants by birthplace. However, enclave markets do not have a significant impact on the self-employment outcomes of the Australian-born children of immigrants. The dual cross-section approach shows that the cross-section self-employment growth among immigrants is predominantly an adjustment effect rather than a cohort effect.
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Krmíček, Lukáš, and Martin Závacký. "Triaxial Compression Testing of Multicomponent Geomaterials from Quartz-Poor (Syenitic) Systems." GeoScience Engineering 63, no. 4 (2017): 1–7. http://dx.doi.org/10.1515/gse-2017-0016.
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AbstractThis paper focuses on mafic microgranular enclaves enclosed in quartz-poor igneous rocks and their effect on strength properties of the rock massif. The study examines host rock–enclave multicomponent geomaterials from enclave-bearing syenitic rocks from the Třebíč Massif exposed in the Královec quarry near Jaroměřice nad Rokytnou in the Czech Republic. A series of laboratory tests were performed to describe strength properties of individual constituents of the multicomponent geomaterials. We mainly focused on triaxial compression tests, however, rebound hardness, uniaxial compressive strength and indirect tensile strength were determined as well. The obtained results indicate that enclaves and even the contact zones between the enclaves and host rocks do not have any negative influence on the rock strength. In contrast, enclaves represent “stress concentrators” within such multicomponent systems. Strength properties of various multicomponent geomaterials are practically an unexplored topic in the field of rocks mechanics and future studies are needed to establish a robust database describing the behaviour of such geocomposites.
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Delpla, Isabelle. "State Liability for Failure to Protect Others. Srebrenica Cases." Südosteuropa 66, no. 2 (2018): 245–71. http://dx.doi.org/10.1515/soeu-2018-0018.
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Abstract Over recent years, a number of legal decisions have been taken that represent real novelties in the field. They address state liability towards foreigners in a realm where immunity has long prevailed. Dutch courts have condemned the Dutch state for failure to protect Bosniacs after the fall of the enclave of Srebrenica in 1995. The novelty of these court decisions is most apparent when they are compared to the previous investigations and reports on the fall of the Srebrenica enclave, which had the intended or de facto effect of leaving aside state liability. This article focuses on this comparison. The decisions of the Dutch court represent a change with regard to a trend in which collective responsibility was reduced to a scarecrow argument, where state liability for genocide was limited to the obligation to address criminal responsibility, and where co-agency was a shield preventing the attribution of state responsibility. Not only do these court decisions sanction state liability, they also address the victims and even grant them reparations.
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Boire, Sidiki, and Kevin S. Nell. "The enclave hypothesis and Dutch disease effect: A critical appraisal of Mali's gold mining industry." Resources Policy 74 (December 2021): 102398. http://dx.doi.org/10.1016/j.resourpol.2021.102398.
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Shin, Eun Jin. "Unraveling the Effects of Residence in an Ethnic Enclave on Immigrants’ Travel Mode Choices." Journal of Planning Education and Research 37, no. 4 (2016): 425–43. http://dx.doi.org/10.1177/0739456x16663309.
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This article examines the relationship between immigrants’ residence in an ethnic enclave and use of alternative modes of transportation. Ethnic enclaves may offer stronger social networks, which may affect mode choice. Using the 2012–2013 California Household Travel Survey, I find that immigrants residing in ethnic enclaves have higher rates of household-external carpooling for nonwork trip purposes than immigrants residing outside ethnic enclaves. I find no difference in the rate of transit use, once built environment characteristics are taken into account. External carpools require arrangements between people in different households, and thus may reflect the social network effect of ethnic enclaves.
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Ouyang, Fang, Jun Wei Bi, Jian Wei Han, and Wei Ming Liao. "A Study on the Effect of a Dyke Reinforced by Geotextile-Encased Sand Columns." Advanced Materials Research 919-921 (April 2014): 7–9. http://dx.doi.org/10.4028/www.scientific.net/amr.919-921.7.
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A dyke construction was dealed with geotextile-encased sand columns. The dyke was used to enclose a polder in Hamburg-Finkenwerder, Germany. With the help of geotextile, the columns can be used in very soft soils , even undrained shear strength cu < 15 kN/m2, without excessive bulging. After the system is installed, the dike can be filled immediately. To analysis observed data of the long-term settlements in the dyke, three stages can be gotten i.e. "Primary settlements" - "Secondary settlements" - "Creep settlements". Most settlements occurred during the primary filling, while, only little settlements appeared after that construction was accomplished. The settlement rate decreases from the first settlement stage to the last one. No jump takes place when unloading soft soil. Furthermore, the method shorten time and saved a lot of money.
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Iwara, A. I., F. O. Ogundele, U. W. Ibor, V. M. Arrey, and O. E. Okongor. "Effect of Vegetation Adjoining Tourism Facilities on Soil Properties in the Tourism Enclave of Cross River State." Research Journal of Applied Sciences 6, no. 4 (2011): 276–81. http://dx.doi.org/10.3923/rjasci.2011.276.281.
Full textDissertations / Theses on the topic "Effet enclume"
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Demmou, Karim. "Nanoindentation, viscoplasticité et piézo-mécanique de films de dithio-phosphate de zinc triboformes." Ecully, Ecole centrale de Lyon, 2007. http://www.theses.fr/2007ECDL0031.
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Utilisés depuis les années 30, les dithiophosphates de zinc sont des additifs de lubrification possédant de bonnes propriétés anti-oxydantes, anti-usure et extrême pression grâce à la formation de films protecteurs sur les surfaces frottantes. L'introduction，dans les années 90，des pots d'échappement catalytiques a entraîné l’émission de normes de plus en plus drastiques limitant la teneur en phosphore et en soufre d’huiles de lubrification destinées au transport automobile. Ces additifs étant les seuls apports de phosphore au sein des moteurs à combustion interne，la recherche a été relancée pour comprendre leurs modes d'actions au sein du contact lubrifié et tenter de trouver des remplaçants potentiels. Si l’on a beaucoup appris concernant leur mode de formation，leur structure et leur composition au cours des quinze dernières années, leurs propriétés mécaniques ainsi que leur comportement mécanique restent en discussion. Ce travail tente d' apporter des éléments de réponse quant à leur comportement mécanique au sein du contact. Dans un premier temps, grâce à la technique de nanoindentation ，les propriétés mécaniques de tribofilms formés à partir d'additifs différents ont été mesurées et comparées vis à vis des différences structurelles，morphologiques et de composition des tribofilms. Puis，dans le but de nous approcher des conditions réelles de contact，ces propriétés mécaniques ont évaluées en fonction de la température et de la vitesse de déformation Nous avons également exploré la propriété de ces tribofilms à augmenter leur module d'élasticité lorsque la pression augmente (effet enclume) à travers des essais à pression hydrostatique élevée. Nous avons ainsi pu mettre en évidence ，sous pression de contact élevée, une relative indépendance des propriétés mécaniques des tribofilms vis-à-vis du type d'additif utilisé. Nous avons également pu montrer qu'à partir d'une température de 60°C environ le comportement du tribofilm évoluait, passant d'un caractère viscoplastique à un caractère que nous avons qualifié de « rhéofluidifiant ». Enfin, l’étude des tribofilms après un cycle compression-décompression a mis en évidence la réversibilité de l’effet enclume dans le domaine de pression étudié<br>Used since the thirties, zinc dithiophosphates are lubricant additives having good antioxidant, anti-wear and extreme pressure properties thanks to the formation of protective films on rubbing surfaces. The introduction of catalytic mufflers in the Nineties, induced the emission of increasingly drastic standards limiting the content of phosphorus and sulphur in lubrication oils intended for automobile transport. These additives being the only phosphorus contributions within internal combustion engines, research was started again to understand their lubricating action modes within the contact and to try to find out potential substitutes. If one learned much concerning their formation mode , their structure and their composition during the last fifteen years，their mechanical properties as their mechanical behavior remain under discussion. This work tries to bring replies about their mechanical behavior within the contact. First, thanks to the nanoindentation technique, the mechanical properties of the tribofilms formed from different additives were measured and compared to the structural morphological and composition between the tribofilms. Then, with the aim of approaching actual conditions of contact, these mechanical properties were evaluated according to the temperature and the deformation rate. We also explored the property of these tribofilms to increase their elastic modulus when the pressure increases (anvil effect) through tests with high hydrostatic pressure. We have highlighted，under high contact pressure，a relative independence of the mechanical properties of the tribofilms with respect to the type of additive used. We have also shown that starting from a temperature of approximately 60°C, the behavior of the tribofilm evolved, passing from a viscoplastic nature to a character which we described as “shear-thinning-like”. Lastly, the study of the tribofilm after a compressiondecompression cycle highlighted the reversibility of the anvil effect in the studied range of pressure
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Roche, Soline. "Propriétés viscoélastiques et plastiques par nano-indentation de couches minces polymères solides : étude en température et en pression." Ecully, Ecole centrale de Lyon, 2004. http://www.theses.fr/2004ECDL0013.
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Le sujet de cette étude porte sur la caractérisation mécanique en nanoindentation et nanorayure de couches minces polymères. L'objectif est d'améliorer la compréhension du comportement élastique d'un film mince polymère déposé sur un substrat dur. Des essais de nanoindentation et nanorayure sont réalisés sur des couches minces déposées sur différents substrats. Un modèle rhéologique est utilisé afin d'extraire les propriétés élastiques du film seul à partir de la réponse mesurée, correspondant au système {film+substrat}. Un phénomène caractéristique des couches minces polymères est mis en évidence : I'effet enclume. En indentation, il s'exprime de deux façons différentes : une augmentation du module de conservation du film avec la dureté, liée au durcissement du film et une diminution du facteur de perte du film avec la dureté, qui s'explique par I'augmentation de la température de transition vitreuse. En rayure, cet effet se manifeste par une augmentation des propriétés mécaniques du film. Au cours de cette étude, la présence de contraintes résiduelles, majoritairement d'origine thermique, est mise en évidence. Une méthode de détermination des contraintes résiduelles d'un film mince polymère est présentée Une interprétation de l’effet enclume est proposé. Celui-ci correspond à la mise en pression d'un film mince confiné entre I'indenteur en diamant et le substrat dur. Ses propriétés mécaniques augmentent avec la pression hydrostatique. Ce phénomène est d'autant plus sensible pour des films de faible épaisseur (<50 µm) dont les propriétés mécaniques sont nettement inférieures à celles du substrat Une étude en température montre que les courbes isothermes du module de conservation en fonction de la pression, sont décalées. L'effet enclume peut alors être décrit par une courbe unique, en appliquant les constantes additives déterminée pour une température de référence donnée. Il en est de même pour le facteur de perte du film. Enfin, les conséquences de I' effet enclume sur les propriétés d'usage des revêtements polymères sont étudiées : la résistance à la rayure et I'adhérence sur le substrat. Une application fondamentale des couches minces est étudiée : les revêtements multicouches. Il semble que I'effet enclume soit un phénomène à considérer afin d'améliorer la résistance à la rayure d'un revêtement mono ou multicouche. Les résultats obtenus sur les couches minces permettent de choisir deux formulations, de type topcoat et basecoat, afin de former un revêtement bicouche performant. Nous avons montré que la présence d'un primaire d'adhérence mou entre un topcoat et un substrat dur permet d'améliorer la performance à la rayure du revêtement final<br>The topic of this study was to mechanically characterize in nanoindentation and nanoscratch thin polymers layers. The goal is to improve the understanding of thin polymer layer elastic behavior laid on hard substrate. Tests in nanoindentation and nanoscratch were done on thin polymer films laid on different substrates. A rheologic model was used in order to extract the film elastic properties from the measured value linked to {film+substrate}. A specific behavior of thin polymer film has been identified: the anvil effect. In indentation, it is observed in two different ways : increase of the conservation film modulus with the hardness, linked to the film hardening, and decrease of the loss tangent with the hardness, which is explained by increasing the vitreous transition temperature. In scratch test, this effect is related to the increase of the film mechanical properties. Nanoindentation tests have highlighted residual stresses, mainly thermal driven. A new methodology to characterize those residual stresses for a thin polymer film was presented. An interpretation of the anvil effect is proposed. This effect is linked to thin layer pressurized, confined between diamond indenter and hard substrate. Its mechanical properties grow with hydrostatic pressure. This phenomenon is greater for thin layers (< 50μm) with lower mechanical properties than those of the substrate. A logarithmic type evolution law is proposed. A temperature study show isothermal curves of the conservation modulus with the pressure are shifted. The anvil effect can be described by a unic curve, applying additive constants determined at a given reference temperature. It is the same for the film loss tangent. Moreover, the consequences of the anvil effect on the use properties of polymer coating are analyzed: scratch resistance and the adhesion to substrate. A fundamental application of thin film was studied multilayer coatings. It seems that anvil effect is a phenomenon to consider for improvement of mono or multilayer coating scratch resistance. The results obtained on thin layers allow to choose two mix of basecoat and topcoat in order to have an improved bilayer. We have demonstrated that a basecoat between the topcoat and the hard substrate allow an improved scratch resistance of the final coating
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Sonneville, Camille. "Étude des propriétés élastiques des verres d’oxydes sous haute pression : implications structurales." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10114/document.
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Le comportement des verres sous pression, lié à leurs structures topologiques, est un enjeu majeur à la fois fondamental et appliqué. L’anomalie élastique de la silice à 2,5GPa est un phénomène connu et son existence est plus que probable dans le verre de GeO2. Il semblait alors légitime de questionner son existence dans des verres plus répandus de compositions chimiques complexes comme les verres alumino sodo silicatés. L’anomalie élastique a été étudiée in situ par Diffusion Brillouin et Raman pour le verre de GeO2 et trois verres alumino sodo silicaté de compositions chimiques : (Al2O3)X(Na2O)25−X(SiO2)75 où X=0, 6 et 12%. Il a été montré que l’existence de l’anomalie de compressibilité dans le domaine élastique n’était pas réduite qu’à la silice uniquement mais au contraire persistait sur un vaste domaine de compositions chimiques et semblait être liée à la présence d’anneaux à 6 tétraèdres. Au delà de la limite élastique, les modifications structurales à l’origine du phénomène de densification permanente ont été étudiées pour la silice, le verre de GeO2 et six verres d’alumino sodo silicatés (contenant X=0, 2, 6, 9, 12 et 16% d’Al2O3). Tout d’abord nous avons observé par diffusion Brillouin la disparition progressive de l’anomalie élastique de la silice avec la densification. Ce phénomène a été interprété en termes de transformations induites par la pression d’une forme amorphe basse densité (LDA) en une forme amorphe haute densité (HDA) : LDA → HDA. Des études in situ et ex situ par Diffusion Brillouin et Raman, Résonance Magnétique Nucléaire (RMN) et aussi de Spectroscopie d’Absorption des Rayons X proche du seuil (XANES) ont montré que les modifications structurales à l’origine de la densification permanente dépendaient grandement de la composition chimique. En particulier la présence de cation sodique semble favoriser les modifications à courte portée comme la formation d’espèces hautement coordonnées d’aluminium ou encore de silicium ainsi que la dépolymérisation du réseau. Au contraire les verres les plus riches en aluminium semblent montrer une densification plus proche structurellement de celle de la silice pure c’est à dire modifiant principalement l’ordre à moyenne distance avec diminution de l’angle inter-tétraèdre et de la taille des anneaux<br>The structural study of glasses under pressure is of fundamental interest in Physics, Earth Science and is technologically important for the comprehension of industrial material properties. The elastic anomaly at 2.5GPa in pure silica glass is a well known phenomenon and its existence is more than likely in GeO2 glass. In this work the persistence of the elastic anomaly in more complex and more widely glass compositions as sodium alumino silicate glasses was studied. The elastic anomaly was studied in situ in GeO2 and three sodium alumino silicate glasses by Brillouin and Raman scattering. The studied sodium alumino silicate glasses had the following compositions : (Al2O3)X(Na2O)25−X(SiO2)75 where X=0, 6 et 12% and is the molar percentage of Al2O3. The elastic anomaly was shown to persist in a broad domain of chemical compositions thus its existence is not reduced to pure silica glass. Its existence seems to be linked to the presence of 6 membered rings. Beyond the elastic limit, the structural modifications was studied in pure silica, GeO2 glass and sodium alumino silica glasses (with X=0, 2, 6, 9, 12 et 16% of Al2O3) in order to structurally better understand the densification phenomenon. Firstly the elastic anomaly was studied by Brillouin scattering experiments, was shown to progressively disappear with the densification. This progressive disappearance was interpreted in terms of a progressive structure induced transformation from a Low Density Amorphous form (LDA) into a High Density Amorphous form (HDA) : LDA → HDA. In situ and ex situ studies by Brillouin and Raman scattering, Nuclear Magnetic Resonance (NMR) and X-ray Absorption Near Edge Structure (XANES) showed that the pressure induced structural transformation was highly dependent of the glass chemical composition. For instance the presence of sodium cations promotes short range order modifications, such as formation of highly coordinated species (Al, Si) and network depolymerization. On the other hand, glasses with a high aluminum concentration show a densification process closer to that of pure silica glass, with mainly middle range order structural modifications such as a decrease of the inter-tetrahedral angle or ring size decrease
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Amiguet, Élodie. "Déformation expérimentale de diopside dans les conditions de pression et température du manteau supérieur." Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10001/document.
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La plasticité des minéraux aux conditions pression et température du manteau supérieur terrestre joue un rôle majeur dans les grand processus qui affectent la dynamique de l'intérieur de la Terre. Les propriétés des minéraux du manteau restent cependant mal connues à ce jour. L'objectif de ce travail est d'étudier la déformation sous pression des clinopyroxènes (au travers du diopside), qui sont un des constituants majeur du manteau supérieur. Des monocristaux orientés et des polycristaux de diopside ont été déformés dans les conditions de pression du manteau supérieur et pour des températures comprises entre 1000°C et 1400°C. Les expériences de déformation ont été réalisées en presse multi-enclume de type D-DIA couplée à un rayonnement synchrotron permettant la mesure in situ de la contrainte et de la déformation. Les microstructures des échantillons après déformation ont été caractérisées en Microscopie Electronique en Transmission. Les données mécaniques nous ont permis de déterminer la loi rhéologique de haute pression pour les systèmes 1/2<110> {110 }. A haute pression et haute température, les glissements 1/2<110> et [001] sont dominants. Les glissements [100] et [010], plus difficilement activables à basse pression et haute température, le restent à haute pression. Des modélisations VPSC basées sur nos résultats expérimentaux rendent parfaitement compte des textures observées dans nos polycristaux déformés expérimentalement comme de celles des échantillons déformés naturellement. Les clinopyroxènes ont tendance à réduire l'anisotropie sismique du manteau supérieur<br>The plasticity of mineraIs under Earth's upper mantle conditions plays a major role in the processes that affect the dynamics of the Earth's interior. The properties of mantle mineraIs are still not weIl constrained. The purpose of this work is to study the deformation of clinopyroxenes (taking diopside as a proxy) under pressure since they are a major constituent of the upper mantle. Oriented single-crystals as weIl as polycristals of diopside were deformed under upper mantle pressures and temperatures. Deformation experiments have been conducted using a D-DIA multi-anvil press coupled with synchrotron radiation in order to perform in situ stress and strain measurements. The microstructures of deformed samples were characterized by Transmission Electron Microscopy. Mechanical data have enabled us to determine the high-pressure rheological law for 1/2 <110>{110} glide systems. At high pressure and temperatures, 1/2 <110> and [001] slips are dominant while [100] and [010] slips remain the hardest slip systems. VPSC modeIling based on our experimental results agree weIl with the textures observed in our experimentaIly deformed polycrystals as weIl as those in naturaIly deformed samples. We conclude that clinopyroxenes tend to reduce the upper mantle seismic anisotropy
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Bollinger, Caroline. "Rhéologie de l’olivine polycristalline aux conditions du manteau supérieur : étude en D-DIA." Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10038/document.
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Ce manuscrit présente une étude expérimentale de l’effet de pression sur rhéologie de l’olivine et de la forstérite aux conditions du manteau supérieur. En effet, certains aspects de la géodynamique de l’intérieur de la Terre restent méconnus. En particulier, le manteau supérieur, en convection, présente une anisotropie sismique dont l’amplitude diminue avec la profondeur et l’olivine, composant principal du manteau supérieur, possède des propriétés mécaniques mal comprises. Des polycristaux d’olivine et de forstérite sont déformés en presse D-DIA entre 3 et 8 GPa et 1373-1673 K. A l’aide de rayonnement synchrotron, une méthode d’analyse est mise au point pour mesurer in situ les contraintes et le développement de textures dans les échantillons. Ces résultats sont ensuite complétés par des analyses en microscopie électronique en transmission. Ces données expérimentales permettent de contraindre les lois rhéologiques en déformation par fluage-dislocation, en conditions « hydratées » et jusque 8 GPa. Un effet de pression est observé avec un volume d’activation de 12,8 (5) cm3.mol-1 pour l’olivine. Ce paramètre est de 12,5 ± 5 cm3.mol-1 pour la forstérite, avec un exposant de contrainte déterminé à n’= 2,35 (0,6). L’effet d’eau est moins marqué que celui de la pression, et le fer rend l’olivine plus ductile que la forstérite. Les textures développées au cours des expériences montrent un plan de glissement (010) dominant en-dessous de 8 GPa. Au-delà, d’autres systèmes de glissement et/ou un autre mécanisme de déformation entrent en jeu. Cette transition de textures est bien corrélée avec la chute d’anisotropie observée dans le manteau supérieur en-deçà de 200 km<br>This manuscript presents an experimental investigation of the effect of pressure on the rheology of olivine and forsterite. Indeed, the geodynamics of the Earth’s interior is not always well understood and needs input for experimental data. The movements of materials in the Earth mantle induce plastic deformation of the constitutive minerals and, particularly, are connected to the rheology of olivine, the main constituent of the upper mantle. Polycristalline olivine and forsterite are deformed in D-DIA at pressure-temperature conditions of the upper mantle, from 3 to 8 GPa and 1373-1673 K. Coupled with synchrotron radiations, applied stresses and developed lattice preferred orientations are measured in situ, with the addition of transmission electron microscopy observations on the run products. From these experimental data, rheological laws have been determined in dislocation-creep regime, under “wet” conditions and below 8GPa for both of these minerals. Pressure effect is observed with an activation volume of 12.8 ± (5) cm3.mol-1 for olivine. For forsterite, this parameter is 12.5 ± 5 cm3.mol-1, with a stress-exponent of n’= 2.35 (0.6). The water influence is apparently not significant compared to the pressure effect, and the iron-bearing olivine is more ductile than iron-free olivine.Developed textures show a dominant slip-system along the (010) plane below 8 GPa. Above, textures are weaker, leading to the conclusion that others slip-systems and/or deformation mechanisms take a part in the plasticity of the olivine. This transition is well correlated with the decreasing of the observed seismic anisotropy of the upper mantle below -200 km
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Nisr, Carole. "Caractérisation des dislocations in situ dans les minéraux sous haute pression." Thesis, Lille 1, 2011. http://www.theses.fr/2011LIL10114/document.
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La plupart des processus géologiques affectant la surface de la Terre sont le reflet des mouvements de convection au sein du manteau terrestre. Ces mouvements sont essentiellement gouvernés par le fluage par dislocations des silicates du manteau et sont à l'origine d'une anisotropie des vitesses des ondes sismiques. Cependant, les mécanismes de déformation de ces minéraux sont mal connus. Les conditions dans les couches les plus profondes sont extrêmes; la température y atteint plusieurs milliers de degrés et la pression est plus d’un million de fois supérieure à la pression atmosphérique. La détermination expérimentale de la plasticité de ces minéraux nécessite des expériences de déformation sous hautes pression et température. Les mécanismes de déformation sont généralement déterminés à partir d'expériences en cellule à enclumes diamants permettant d'atteindre les conditions de pression et de température du manteau. L'objectif de cette thèse visait à développer une nouvelle technique permettant d'étudier les dislocations in situ dans les grains d’un polycristal sous haute pression, directement à partir de leur effet sur les raies de diffraction X. De ce fait, nous avons combiné la diffraction X tridimensionnelle (3D-XRD) à la méthode d'analyse des profils de pics de diffraction (XLPA, X-ray Line Profile Analysis). Les travaux de cette thèse ont été appliqués à la post-perovskite, présente dans la couche D'' à l'interface noyau-manteau et à la stishovite, présente principalement dans les plaques en subduction. Les résultats obtenus sont utiles à la compréhension et la modélisation des mouvements de convection et du développement d'anisotropie sismique dans le manteau<br>The Earth mantle and inner core are submitted to large scale movements of solid materials. The physical process allowing the flow of solid materials is connected to plastic properties and, in particular, dislocations. It is the source of seismic wave velocities anisotropy. However, the deformation mechanisms of deep Earth minerals are poorly understood. Deep in the Earth’s interior, minerals are under extreme conditions; the temperature reaches several thousand degrees and the pressure is more than one million times the atmospheric pressure. The experimental study of the plasticity of those minerals requires deformation experiments under high pressure and temperature. High pressure phenomena are often determined from experiments using diamond anvil cell to reach the conditions of pressure and temperature of the mantle. The objective of this thesis was to develop a new technique for studying dislocations in situ in grains inside a polycrystal under high pressure, directly from their effect on the X ray diffraction profiles. To do so, we combine three-dimensional X-ray diffraction (3D-XRD) to X ray Line Profile Analysis method (XLPA). The development done in this thesis was applied to post-perovskite, the main constituent of the D'' layer at the core-mantle boundary and to stishovite, present mainly in subducting slabs. The results obtained are useful for understanding and modeling of convection and the development of seismic anisotropy in the mantle
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Pandolfi, Silvia. "High-pressure pathways towards new functional Si-based materials with tailored optoelectronic properties and their characterization." Electronic Thesis or Diss., Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2019SORUS459.pdf.
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Dans cet ouvrage, le traitement à haute température et haute pression est utilisé pour développer et optimiser la synthèse de nouvelles formes exotiques du silicium. La synthèse de nouvelles phases de silicium est un point clé dans le développement de technologies à base de Si, en particulier l'énergie solaire. Le développement de nouveaux matériaux à base de silicium à haut rendement pourrait faire face à la fois à l'optimisation des performances et à la réduction des coûts. Au niveau industriel, la haute pression a été principalement utilisée pour la synthèse des diamants et des matériaux super-durs, mais des études récentes ont prouvé qu’elle est également efficace pour la synthèse de nouveaux matériaux à base de silicium à propriétés remarquables pour les applications. Nous abordons ce défi sous tous ses aspects, à partir de l'étude des mécanismes de transition à haute pression jusqu’à la synthèse et à la caractérisation d'un nouveau matériau de silicium. Nous utilisons la diffraction in situ de rayons X à haute-pression haute-température pour observer et caractériser des transitions de phase du silicium et leur dynamique. Grâce à nos résultats, nous donnons de nouvelles perspectives capables de clarifier certains aspects du diagramme de phase du silicium qui étaient encore en discussion. Nous obtenons la première synthèse de silicium hexagonal pur, un défi de longue date dans le domaine. Grâce à notre échantillon de phase pure, nous caractérisons ses propriétés physiques et structurales. Nous prouvons que le silicium hexagonal obtenu à partir du traitement haute pression est sous forme du polytype 4H (séquence d'empilement ABCB). D'autres caractérisations structurelles révèlent une nanostructure hiérarchique dans la morphologie de l'échantillon. La découverte et la caractérisation de nanoparticules quasi-2D accessibles à la manipulation ouvrent de nouvelles perspectives pour le développement de nouveaux dispositifs optoélectroniques<br>In this work, high-pressure high-temperature treatment is used to develop and optimize synthetic pathways to new and exotic forms of silicon. The synthesis of new phases of silicon is a key point in the future development of Si-based technology, especially for solar energy. Development of new Si-based materials with high-efficiency could both optimise the performances and reduce the costs. At an industrial level, high-pressure has been mainly used for the synthesis of diamonds and super-hard materials, but recent studies have proven it also efficient in the synthesis of new silicon-based materials with enhanced properties for applications. We tackle this challenge in all its aspects, starting from the study of transition mechanisms at high-pressure and arriving to the synthesis and characterization of a new silicon material. We use in-situ x-ray diffraction at high-pressure high-temperature conditions to monitor and characterize silicon phase transitions and their dynamics. Our results give new insights that clarify some aspects of the silicon phase diagram that were still a matter of debate. We obtain the first synthesis of pure hexagonal silicon, a longstanding challenge in the field. Thanks to our pure-phase sample, we characterize its physical and structural properties. We prove that hexagonal silicon obtained from high-pressure is in the form of 4H polytype (ABCB stacking sequence). Further structural characterizations reveal a hierarchical nanostructure in the pristine morphology of the sample. Discovery and characterization of discrete quasi-2D nanoparticles accessible for manipulation opens new perspectives for the design of new optoelectronic devices
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Tran, Trung Hieu. "Élasticité des verres silicatés sous pression : étude par diffusion Brillouin." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20181.
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Nous étudions la réponse élastoplastique des verres silicatés à de fortes contraintes par diffusion Brillouin de la lumière. Des cartographies micro-Brillouin 3D du champ de densité résiduelle sont obtenues dans l'empreinte plastique laissée par une indentation Vickers et comparés à des modélisations par éléments finis. L'analyse conjointe des mesures réalisées en enclumes diamants sur la silice dans le domaine de déformation élastique et des données de la littérature fait apparaître que le durcissement anormal des modules élastiques avec la température est d'origine dynamique. La température à laquelle le durcissement est mis en évidence augmente avec la pression hydrostatique appliquée. Nous observons également que la densification progressive de la silice diminue fortement l'amplitude du maximum dans le frottement interne observé à 2 GPa de même qu'elle supprime l'anomalie dans la compressibilité<br>We study the elastoplastic response of silicate glasses at high stresses with Brillouin light scattering. 3D micro-Brillouin mapping residual density field are obtained in the plastic region left by a Vickers indentation. Maps are compared with finite element modeling. The joint analysis of new high-pressure measurements in a diamond anvil cell on silica in the elastic domain and literature data revealed that the abnormal hardening of elastic moduli with temperature is of dynamical origin. The onset temperature of the hardening increases with increasing applied hydrostatic pressure. We also observe that densification of silica strongly reduces the amplitude of the maximum in internal friction observed at 2 GPa as well as it suppresses the compressibility anomaly
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Montagnac, Gilles. "Spectroscopie Raman résonnante UV in situ à haute température ou à haute pression." Thesis, Lyon, École normale supérieure, 2012. http://www.theses.fr/2012ENSL0784/document.
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Dans cette thèse, la spectroscopie Raman résonante UV (SRRUV) est appliquée pour la première fois à l'étude ‘in situ’ de matériaux carbonés à très haute température (> 2000 K) ou à haute pression (< 1 GPa).La thèse est constituée de trois parties. La première aborde notre travail de caractérisation en SRRUV (1) de films semi conducteurs de diamants ultra-nano-cristalins, (2) des kérogènes issues de météorites chondritiques et de charbons, et (3) des tholins, échantillons de carbone-hydrogène-azote, synthétisés comme analogues de l'atmosphère de Titan.L’intérêt pour ces phases du carbone en planétologie et en science des matériaux nous a poussé à mettre en œuvre leur étude ‘in situ’ en SRRUV. La seconde partie de la thèse est consacrée au développement d'une platine chauffante, grâce à laquelle les spectres Raman du graphite sous sa forme pyrolitique et HOPG ont été mesurés jusqu'à 2700 K. Ces données valident les modèles anharmoniques théoriques d’interaction électron-phonon et phonon-phonon. Le spectre Raman du graphite a été étalonné en fonction de la température et devient un « thermomètre » à très haute température.Dans la troisième partie de cette thèse, une presse à enclumes opposées a été modifiée pour suivre en SRRUV les changements structuraux de cristaux moléculaires très luminescents. Les vibrations intramoléculaires du cristal de pérylène sont étudiées sous pression par SRRUV. Ce composé est un cristal formé de molécules organiques polyaromatiques, avec des propriétés de semi-conducteur. Les effets de la pression sur certains modes de vibrations sont non linéaires et mettent en évidence des changement structuraux et de planéité de la molécule<br>I applied UV resonant Raman spectroscopy (UVRRS) to an ‘in situ’ study of carbon materials at very hight temperature (> 2000 K) or at high pressure (< 1 GPa).The advantages of UVRRS are presented in the first part of this PHD thesis, and used to investigate details of the composition and structure of disordered carbon materials such as: (1) n-type nanocrystalline films, (2) carbonaceous matter in chondrites and (3) tholins, HCN synthetic samples of Titan 's atmosphere.‘In situ’ Raman studies are limited to 2000 K by the visible black-body emission. I designed a high temperature cell to perform UVRRS above this limit. The second part of the manuscript presents Raman spectra of pyrolitic graphite and HOPG up to 2700 K. This data are consistent with anharmonic models up to 900 K, and show the coupling effects of electron-phonon and phonon-phonon. The last one dominates the anharmonicity above 1000 K. The Raman spectra was calibrated as a function of temperature and became a “thermometer” up to 2700 K.For high pressure measurements in the third part, I modified an anvil cell to study by UVRRS, the vibrational changes induced by pressure on very luminescent molecular organic crystals. I present an analysis at 244 nm of resonant Raman modes of perylene crystal under hydrostatic pressure up to 0.8 GPa. Some of them have a non linear feature under pressure, revealing structural and planar modifications of the molecules
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Rannou, Isabelle. "Etudes sous pression de la transition de phase interpolytypique du sulfure de gallium." Paris 6, 1986. http://www.theses.fr/1986PA066063.
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Etude entre 0 et dollar GPA, permettant de mettre en évidence une transition de basse pression à 1,6 GPA; mesures de l'absorption optique et de l'indice de réfraction, de la diffusion Raman et de la diffusion Brillouin; analyse des variations a la transition. Description satisfaisante des variations des modes de vibration au moyen d'un modèle de dynamique réticulaire a forces centrales.
Books on the topic "Effet enclume"
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Weissman, Susan. Final Judgement and the Dead in Medieval Jewish Thought. Liverpool University Press, 2020. http://dx.doi.org/10.3828/liverpool/9781906764975.001.0001.
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Through a detailed analysis of ghost tales in the Ashkenazi pietistic work Sefer ḥasidim, this book documents a major transformation in Jewish attitudes and practices regarding the dead and the afterlife that took place between the rabbinic period and medieval times. The book reveals that a huge influx of Germano-Christian beliefs, customs, and fears relating to the dead and the afterlife seeped into medieval Ashkenazi society among both elite and popular groups. In matters of sin, penance, and posthumous punishment, the infiltration of Christian notions was so strong as to effect a radical departure in Pietist thinking from rabbinic thought and to spur outright contradiction of talmudic principles regarding the realm of the hereafter. Although it is primarily a study of the culture of a medieval Jewish enclave, this book demonstrates how seminal beliefs of medieval Christendom and monastic ideals could take root in a society with contrary religious values — even in the realm of doctrinal belief.
Book chapters on the topic "Effet enclume"
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Bulnes, Francisco, Juan Carlos García-Limón, Víctor Sánchez-Suárez, and Luis Alfredo Ortiz-Dumas. "Numerical Simulations of Detections, Experiments and Magnetic Field Hall Effect Analysis to Field Torsion." In Recent Advances on Numerical Simulations [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96779.
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Field torsion models are considered from the experiments realized in electronic-dynamical devices and magnetic censoring of a Hall Effect sensor to detect torsion under electrical restricted conditions and space geometry. In this last point, are obtained 2D and 3D-models of torsion energy, which enclose the field theory concepts related with torsion, and open several possibilities of re-interpretations that can be useful in technological applications in the future. Likewise, are considered some measurements that evidence the torsion as field observable. Through geometrical models obtained from theorems and other results are demonstrated the conjectures required to understanding of torsion, as a geometrical and physics invariant most important in the deep study of the Universe. Also, applications in astrophysics and cosmology of these geometrical models are obtained to show Universe phenomena understudy of torsion.
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Chan, Catherine S. "Crossing Imperial Borders." In The Macanese Diaspora in British Hong Kong. Amsterdam University Press, 2021. http://dx.doi.org/10.5117/9789463729253_ch01.
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The lives of a Macanese clerk, a businessman and a newspaper editor reveal the dynamic and continuous relationship between Macau and Hong Kong. Owing to the lack of exciting opportunities in the Portuguese enclave, aspiring Macanese men braved their first move to British Hong Kong in 1842, pulled by pre-existing employment, partnerships and unfulfilled dreams. The arrival of the Macanese caused a domino effect, prompting Catholic missionaries to transfer their headquarters to Hong Kong where they would set up churches and schools that catered to a growing population. As against common perceptions of Macau as a ‘prelude’ to Hong Kong’s acquisition, this chapter shows how Macanese migrants created an unprecedented meeting point between the Portuguese and British imperial spheres.
Conference papers on the topic "Effet enclume"
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Sato, Toru, Kentaro Mizumukai, Chun-ju Lin, Shigeru Tabeta, and Daisuke Kitazawa. "Predictions of Ecological Effects of Artificial Upwelling in Semi-Enclosed Bay and Enclosed Lake." In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/omae2009-79687.
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An apparatus, which mixes waters in upper and lower layers in density stratification and discharges the mixture at the middle depth, has made a remarkable success in enhancing water quality for ecosystems in a small semi-enclosed bay and an enclose lake in Japan. In this study, we conducted numerical simulations by using a three-dimensional tidal current model and an ecosystem model to predict the effects of the apparatus in two different waters: a larger semi-enclosed bay and an enclosed lake. Isahaya Bay in Ariake Sea was chosen as the former case to see how effectively the apparatus can reduce oxygen-deficient water, and Feng-Shan dam-lake located in South Taiwan represents the latter case, where we are interested in the effect of the apparatus on reduction of Microcystis aeruginosa, which is harmful blue-green alga and causes environmental problems in the neighbouring area. As a result, it is suggested that the apparatus averages temperature of water vertically in its vicinity and this increases phytoplankton in the lower layers resulting in reducing oxygen-deficient water in Isahaya Bay. However, it is not very effective in reducing the blue-green alga in the Taiwanese lake because the temperature in the lower layer is still preferable for the alga even after the mixing.
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Arifeen, Shams U., Victor Wolemiwa, Dominic Nwoke, et al. "Finite Element Analysis and Fatigue Life Prediction of an Aluminum Alloy Braze for High Temperature Thermoelectric Generator Package Assembly." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-38829.
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Thermoelectric generators (TEGs) are solid state devices that convert thermal energy into electrical energy using the Seebeck effect. They can be used for energy harvesting in trucks and passenger vehicles by taking advantage of the temperature difference between the exhaust pipes and ambient environment. The key issue with thermoelectric devices today is the demand for increased operating temperatures while maintaining adequate reliability and low cost. Since, TEGs are subjected to sub-critical thermal cyclic loading, ensuring satisfactory reliability is important for commercially viable products. TEGs used in passenger vehicles should be able to withstand extreme environmental conditions such as high temperature, shock and mechanical vibration [1]. Since the operating temperatures of TEGs can reach temperatures higher than 500 °C, aluminum brazes offer a good high temperature solution for die attach applications. The thermoelectric materials of TEGs are prone to oxidation and sublimation. A solution to minimize these phenomena is to enclose the TEG device in a hermetic package. This paper analyzes the reliability of aluminum alloy braze Al 718 (12% Si, 88% Al) used in TEG packages under fatigue loading. A power cycling temperature fluctuation method was employed to simulate the operating conditions of the TEGs for passenger vehicle. Low cycle fatigue simulations were performed using the direct cyclic approach embedded in the finite element software ABAQUS. Direct cyclic approach uses an extrapolation technique, which allows for efficient and computationally inexpensive simulations. The numerical model was validated using experimental test data. A validated damage model was used to analyze the cyclic damage evolution in the aluminum alloy braze for the hermetic TEG packages.