56 research outputs found

    Local linear estimation of conditional cumulative distribution function in the functional data: Uniform consistency with convergence rates

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    summary:In this paper, we investigate the problem of the conditional cumulative of a scalar response variable given a random variable taking values in a semi-metric space. The uniform almost complete consistency of this estimate is stated under some conditions. Moreover, as an application, we use the obtained results to derive some asymptotic properties for the local linear estimator of the conditional quantile

    Analysis of the resistance to crack propagation in SENT test specimens printed in ABS using parallel or crossed filaments between layers

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    Additive manufacturing techniques continue to develop and cover all industrial fields. However, the performances of aspect and mechanical behavior of the parts obtained by this process remain to be mastered and are still the subject of current research works. Among these performances, the one corresponding to the resistance to the propagation of cracks. In order to improve this very interesting property in various industrial fields, it is desirable to master the understanding of crack propagation in this type of structure obtained by 3D printing. The objective of this paper is to analyze and understand the effect of the adopted raster angle on the crack propagation in SENT specimens obtained by FDM in ABS (Acrylonitrile-Butadiene-Styrene). Two approaches were developed: one is experimental to determine the critical stress intensity factor KIC and the other is numerical to predict the possible paths of crack propagation

    Analysis of the resistance to crack propagation in SENT test specimens printed in ABS using parallel or crossed filaments between layers

    Get PDF
    Additive manufacturing techniques continue to develop and cover all industrial fields. However, the performances of aspect and mechanical behavior of the parts obtained by this process remain to be mastered and are still the subject of current research works. Among these performances, the one corresponding to the resistance to the propagation of cracks. In order to improve this very interesting property in various industrial fields, it is desirable to master the understanding of crack propagation in this type of structure obtained by 3D printing. The objective of this paper is to analyze and understand the effect of the adopted raster angle on the crack propagation in SENT specimens obtained by FDM in ABS (Acrylonitrile-Butadiene-Styrene). Two approaches were developed: one is experimental to determine the critical stress intensity factor KIC and the other is numerical to predict the possible paths of crack propagation

    Caractérisation d'une entaille dans un milieu homogène par une approche asymptotique

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    Dans cette étude, une méthodologie de calcul du facteur d'intensité de contraintes a été développée. La particularité de cette méthode consiste en la détermination par un calcul itératif par éléments finis de l'ordre de la singularité qui sera intégré dans la formulation de MARTIN L et al. et dans celle de G. GROSS et MENDELSON pour déterminer ce facteur d'intensité de contraintes. Les résultats obtenus par cette approche ont été validés par la littérature (LEGUILON D)

    Experimental investigation of surface roughness effect on fatigue performance of AISI 1045 carbon steel and fatigue limit prediction

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    In fatigue life, surface integrity perform a major role to determine the fatigue lifetime. It could differ greatly among specific cases even for the same solicitations. Indeed, the manufacturing process carries modifications on surface state, residual stresses and the microstructure which affects the fatigue behavior of mechanical parts.This article investigate the effect of surface roughness on the fatigue strength of AISI 1045 carbon steel obtained by the turning process. The work carried out consists in testing in uniaxial fatigue different batches of specimens which have a controlled surface state. The S-N curves obtained present a strong dependence between fatigue performance and surface state. Based on the surface topography, a model for predicting fatigue limit will be adopted

    Experimental investigation of surface roughness effect on fatigue performance of AISI 1045 carbon steel and fatigue limit prediction

    Get PDF
    In fatigue life, surface integrity perform a major role to determine the fatigue lifetime. It could differ greatly among specific cases even for the same solicitations. Indeed, the manufacturing process carries modifications on surface state, residual stresses and the microstructure which affects the fatigue behavior of mechanical parts. This article investigate the effect of surface roughness on the fatigue strength of AISI 1045 carbon steel obtained by the turning process. The work carried out consists in testing in uniaxial fatigue different batches of specimens which have a controlled surface state. The S-N curves obtained present a strong dependence between fatigue performance and surface state. Based on the surface topography, a model for predicting fatigue limit will be adopted

    Flexible Electronics Sensors for Tactile Multi-Touching

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    Flexible electronics sensors for tactile applications in multi-touch sensing and large scale manufacturing were designed and fabricated. The sensors are based on polyimide substrates, with thixotropy materials used to print organic resistances and a bump on the top polyimide layer. The gap between the bottom electrode layer and the resistance layer provides a buffer distance to reduce erroneous contact during large bending. Experimental results show that the top membrane with a bump protrusion and a resistance layer had a large deflection and a quick sensitive response. The bump and resistance layer provided a concentrated von Mises stress force and inertial force on the top membrane center. When the top membrane had no bump, it had a transient response delay time and took longer to reach steady-state. For printing thick structures of flexible electronics sensors, diffusion effects and dimensional shrinkages can be improved by using a paste material with a high viscosity. Linear algorithm matrixes with Gaussian elimination and control system scanning were used for multi-touch detection. Flexible electronics sensors were printed with a resistance thickness of about 32 ÎĽm and a bump thickness of about 0.2 mm. Feasibility studies show that printing technology is appropriate for large scale manufacturing, producing sensors at a low cost

    Expression of Nestin by Neural Cells in the Adult Rat and Human Brain

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    Neurons and glial cells in the developing brain arise from neural progenitor cells (NPCs). Nestin, an intermediate filament protein, is thought to be expressed exclusively by NPCs in the normal brain, and is replaced by the expression of proteins specific for neurons or glia in differentiated cells. Nestin expressing NPCs are found in the adult brain in the subventricular zone (SVZ) of the lateral ventricle and the subgranular zone (SGZ) of the dentate gyrus. While significant attention has been paid to studying NPCs in the SVZ and SGZ in the adult brain, relatively little attention has been paid to determining whether nestin-expressing neural cells (NECs) exist outside of the SVZ and SGZ. We therefore stained sections immunocytochemically from the adult rat and human brain for NECs, observed four distinct classes of these cells, and present here the first comprehensive report on these cells. Class I cells are among the smallest neural cells in the brain and are widely distributed. Class II cells are located in the walls of the aqueduct and third ventricle. Class IV cells are found throughout the forebrain and typically reside immediately adjacent to a neuron. Class III cells are observed only in the basal forebrain and closely related areas such as the hippocampus and corpus striatum. Class III cells resemble neurons structurally and co-express markers associated exclusively with neurons. Cell proliferation experiments demonstrate that Class III cells are not recently born. Instead, these cells appear to be mature neurons in the adult brain that express nestin. Neurons that express nestin are not supposed to exist in the brain at any stage of development. That these unique neurons are found only in brain regions involved in higher order cognitive function suggests that they may be remodeling their cytoskeleton in supporting the neural plasticity required for these functions

    Evaluation d'anticorps polyclonaux diriges contre les endosomes: aspects biochimiques et structuraux. Identification d'un polypeptide membranaire conserve au cours de l'Evolution

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    SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 78135 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
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