Etude phénoménologique du frottement des matériaux fibreux souples

Ce travail porte sur l'étude phénoménologique du comportement tribologique des surfaces textiles en vue de mieux comprendre la sensation éprouvée lors du toucher. Les surfaces fibreuses utilisées dans cette étude représentent une gamme assez large de surfaces utilisées dans l'habillement. Les mesures tribométriques sont réalisées dans des conditions inspirées du toucher humain en terme d'aire apparente de contact, de vitesse et de charge normale. Le coefficient de frottement dans quatre directions de la surface est mesuré sous différentes charges. La présence ou non d'une pilosité superficielle et le rôle de l'orientation de cette pilosité sont mis en évidence dans le comportement au frottement de l'étoffe. De plus, une étude d'analyse sensorielle sur le caractère « accrochant » révèle que seul le frottement ne décrit pas l'accrochant et qu'il est nécessaire de prendre également en compte la dureté du matériau

Biallelic loss-of-function variants in PLD1 cause congenital right-sided cardiac valve defects and neonatal cardiomyopathy

Congenital heart disease is the most common type of birth defect, accounting for one-third of all congenital anomalies. Using whole-exome sequencing of 2718 patients with congenital heart disease and a search in GeneMatcher, we identified 30 patients from 21 unrelated families of different ancestries with biallelic phospholipase D1 (PLD1) variants who presented predominantly with congenital cardiac valve defects. We also associated recessive PLD1 variants with isolated neonatal cardiomyopathy. Furthermore, we established that p.I668F is a founder variant among Ashkenazi Jews (allele frequency of ~2%) and describe the phenotypic spectrum of PLD1-associated congenital heart defects. PLD1 missense variants were overrepresented in regions of the protein critical for catalytic activity, and, correspondingly, we observed a strong reduction in enzymatic activity for most of the mutant proteins in an enzymatic assay. Finally, we demonstrate that PLD1 inhibition decreased endothelial-mesenchymal transition, an established pivotal early step in valvulogenesis. In conclusion, our study provides a more detailed understanding of disease mechanisms and phenotypic expression associated with PLD1 loss of function

Thermal failure of carbon nanostructures

The greatest weakness of integrated circuits is thermal. Localized temperature increase can significantly degrade circuit performances, sometimes irreversibly. To tackle this issue, carbon-based materials are envisioned as potential candidates to replace metals like copper, tungsten and aluminium. However, little is known about their failure mechanisms. In this thesis, we studied the thermal degradation mechanisms of graphitic materials (Carbon nanotubes, graphite and graphene). To do so, we first examined the joule-heating induced electrical failure of graphene based devices (electro-burning). From our observations, we identified a thermally heterogeneous electro-burning process driven by localised Joule-heating leading to the propagation of a nanometre-spaced gap. To gain more insight into this degradation, we used a femtosecond laser to induce thermal damage to the graphene locally. Our interpretation reveals that heating a graphitic layer leads to the formation of vacancies resulting in an unstable carbon lattice. Finally, we showed how electro-burning, when controlled, can be an advantage. We use a tightly focused femtosecond laser beam to induce defects in graphene according to selected patterns. We show that the nanogaps in pre-patterned devices propagate along the defect line created by the femtosecond laser with a 92\% success rate. Finally, we performed electrical and thermal simulations of an alternative 3D architecture: carbon nanotubes through-substrate vias covalently bonded to graphene/graphite horizontal interconnects. The structure is highly conductive both thermally and electrically and can sustain higher current densities than currently used copper interconnects. However, our results also indicate that graphite anisotropy could worsen the reliability of the architecture due to higher current crowding.Doctor of Philosoph

Introduction

Hamon Maurice, Rovère Ange. Introduction. In: Être reconnu en son temps : personnalités et notables aux Temps modernes. Actes du 134e Congrès national des sociétés historiques et scientifiques, « Célèbres ou obscurs : hommes et femmes dans leurs territoires et leur histoire », Bordeaux, 2009. Paris : Editions du CTHS, 2012. p. 3. (Actes des congrès nationaux des sociétés historiques et scientifiques, 134-10

Income Disparities in Post-Reform China: A Review of the International Literature

China has experienced spectacular economic growth since 1978, averaging 8 to 9% per year. As a result, on average, people’s standard of living is far higher than ever before in China’s history. However, economic disparities have also widened very significantly during this period, raising questions about the appropriateness and sustainability of existing policies. This book includes the papers from a seminar held in Paris on 20-21 October 2003 to explore the causes of China's growing economic disparities. The seminar was organised by the OECD and the National Development and Reform Commission (NDRC) of China. The papers by Chinese and OECD experts look at the driving forces behind these trends and discuss possible policy responses. The collection presents many comparisons with income inequality trends in OECD countries, including geographic disparities, and looks at ways to improve Chinese data on income distribution

UV–Vis Absorption Spectroscopy of Polonium(IV) Chloride Complexes: An Electronic Structure Theory Study

International audienceMore than a hundred years after its discovery, the chemistry of the polonium radioelement is still largely unknown. However, it is quite clear that the properties of this heavy element (Z = 84) may be affected by relativistic effects, in particular scalar relativistic effects and the so-called spin–orbit coupling (SOC). In this Article, we revisit the interpretation of UV–vis absorption spectra of polonium(IV) complexes in HCl medium, reported decades ago. From the data, two complexes were hypothesized, complex I with a maximum of absorption at 344 nm (at low HCl concentration) and complex II with a maximum at 418 nm (the only visible peak for HCl concentrations above 0.5 M). By monitoring the absorbance at 344 and 418 nm as a function of both the HCl concentration and the pH, complex I was formulated as [Po(OH)Clx]3–x while complex II was formulated as [PoCl2+x]2–x. In this work, we study the ground-state geometries of the [Po(OH)Clx]3–x and [PoCl2+x]2–x complexes for x = 4–2, i.e. for the most probable complexes, with density functional theory (DFT), demonstrating that solvation can remarkably change the geometries of such systems. The electronic excitation energies are then computed with time-dependent DFT (TD-DFT), second-order N-electron valence state perturbation theory (NEVPT2), and contracted spin–orbit configuration interaction (c-SOCI), showing (i) that the SOC must be at play to obtain excitation energies in the right energy domain and (ii) that the quantum chemical calculations point toward x = 4, i.e., toward the [Po(OH)Cl4]− and [PoCl6]2– complexes

Modélisation phénoménologique du comportement tribologique des surfaces textiles

L objectif de ce travail est d améliorer la caractérisation mécanique du toucher des surfaces textiles en déterminant les forces d interaction situées à l interface entre le palpeur et l étoffe. L étude est restreinte au toucher à plat, sans l aspect thermique. La partie expérimentale met en avant l existence de la pilosité de surface. Ce paramètre négligé dans de nombreuses études est mis en évidence par une méthode permettant de calculer la flexion de la pilosité de surface d étoffe présentant une surface dont la pilosité est orientée et longue. Cette méthode permet de confronter le paramètre de flexion de la pilosité vis à vis de la force de frottement. Une seconde méthode qui consiste à prendre en compte l enfoncement du doigt dans la pilosité lors du frottement. Cette méthode propose un critère pertinent basé sur la contrainte de cisaillement existante lors frottement. Pour finir une troisième méthode qui consiste à venir mesurer l énergie acoustique permet de classer les étoffes. Cette méthode est validée car elle suit les résultats obtenus par l Homme lors de la caractérisation microneurographique du toucher d étoffes similaires.The objective of this work is to improve the mechanical characterization of the touch of textile surfaces by determining the forces of interaction located at the interface between the probe and the fabric. The study is restricted to the touch flat, without the thermal aspect. The experimental part specially displayed the existence of the hairiness of surface. This parameter neglected in many studies is highlighted by a method allowing to calculate the bending of the hairiness of fabric surface which having a surface whose hairiness is directed and long. This method makes it possible to confront the bending force of hairiness with the force of friction. A second method consists in taking into account the depression of the finger in hairiness shows that the touch is a complex parameter, which cannot be only characterized by one simple friction. To finish a third method consists in to measure acoustic energy allows to classify the fabrics. This method is validated because it follows the results obtained by the human being during the microneurography characterization of the similar fabric touch.MULHOUSE-SCD Sciences (682242102) / SudocMULHOUSE-ENSISA (682242207) / SudocSudocFranceF

Po(IV) chloride complex: a theoretical and experimental study

International audienc