Optimization of microstructural evolution during laser cladding of Ni based powder on GCI glass molds

International audienceIn the glass industry, laser cladding is an innovative surfacing technique of depositing a layer of nickel to protect glass mold against corrosion, abrasion and thermal fatigue. This method (powder fusion by projection), well known in additive manufacturing represents a real technological leap for the glass industry. However, during laser cladding of Ni-based powder on gray cast iron, cracks can be observed for some process conditions. These cracks are often due to the Heat Affected Zone which creates structural stresses linked to the development of a martensitic structure in the ferritic matrix of the lamellar graphite cast iron. The aim of this work is to observe the impact of laser cladding (without substrate pre-heating usually used to limit cracking) on coating behavior but also on flake-graphite cast iron substrates. The microstructure and the mechanical properties were studied around the interface cladding/substrate. The impact of the processing parameters (power P, scanning speed v and powder feeding rate PFR was studied by using the ANOVA (ANalysis Of VAriance) technique. It has been observed that laser cladding on graphite cast iron without cracking is possible by limiting the linear energy induced by the process. Optimization of the processing parameters in order to obtain the industrial expected geometry of the coating has also been proposed

Crossing boundaries:bras, lingerie and rape myths in postcolonial urban middle-class India

With the processes of modernization, urbanization and the entry of women in the formal labour market in Indian metropolitan spaces, this paper examines how the modern middle-class woman’s sartorial choices become enmeshed in popular rape myths (false beliefs) that serve to blame her for the wearing of western clothing. The paper articulates the ways in which middle-class women’s social realities are shaped by historical, colonial and nationalist ideologies of modernization, constructed and mediated through moral codes of dressing. By drawing upon original and contemporary empirical narratives from the urban spaces of Delhi and Mumbai, we emphasise how everyday sartorial choices, in relation to particularly the bra and lingerie, can reveal the nuanced ways in which Urban Indian Professional Women (UIPW) seek to understand, negotiate, and resist patriarchal power. Our findings shed light on conflicting and contradictory spatial experiences, where some women internalize and negotiate moral codes of dressing, out of fear, and others who transgress are subject to sanctions. Given the paucity of scholarly literature in this area, the paper makes an important theoretical and empirical contribution with its focus on postcoloniality and everyday discursive material spaces of gendered and sexualized dress practices. It argues for the consciousness raising of everyday urban geographies of dress that reveal complicated structures of power that are often deemed hidden

Equity and justice in global warming policy

Many countries are implementing or at least considering policies to counter increasingly certain negative impacts from climate change. An increasing amount of research has been devoted to the analysis of the costs of climate change and its mitigation, as well as to the design of policies, such as the international Kyoto Protocol, post-Kyoto negotiations, regional initiatives, and unilateral actions. Although most studies on climate change policies in economics have considered efficiency aspects, there is a growing literature on equity and justice. Climate change policy has important dimensions of distributive justice, both within and across generations, but in this paper we survey only studies on the intragenerational aspect, i.e.., within a generation. We cover several domains including the international, regional, national, sectoral and inter-personal, and examine aspects such as the distribution of burdens from climate change, climate change policy negotiations in general, implementation of climate agreements using tradable emission permits, and the uncertainty of alternatives to emission reductions

Insuffisance ovarienne prématurée : de la génétique à la clinique

peer reviewedL’Insuffisance Ovarienne Prématurée (IOP) est une pathologie dont la présentation clinique est complexe. Elle survient chez 1% des femmes avant 40 ans, 0,1% avant 30 ans. Les causes sont multiples : les anomalies génétiques, les maladies auto-immunes, les atteintes ovariennes iatrogènes secondaires à la chirurgie, radiothérapie, chimiothérapie, aux facteurs environnementaux tels que les virus, les toxines, le tabac, et aux facteurs métaboliques. Cependant, dans la majorité des cas, l’étiologie de l’IOP est idiopathique

Trisomy 11 in myeloid malignancies is associated with internal tandem duplication of both MLL and FLT3 genes.

In 20 patients with myeloid malignancies and isolated trisomy 11 an internal tandem duplication of the MLL and FLT3 genes was observed in 41% and 31% of the cases, respectively; 80% of the FLT3+ cases showed MLL self-fusion. Concomitant presence of MLL and FLT3 anomalies could be relevant in determining the poor outcome of patients with acute myeloid leukemia with trisomy 11

Multi-scale characterization by neutronography and electron diffraction of Ni coating on Cu-Ni-Al or cast-iron glass molds after laser cladding

International audienceLaser cladding of a Ni based powder on Cu-Ni-Al or cast iron was performed with a 4kW continuous Nd: YAG laser. The Cu-Ni-Al and cast-iron substrates are used for their thermal properties in glass mold industry. But the issue of these materials is their lack of resistance on corrosion and abrasion. The role of the Ni based alloy is to protect the mold without affecting its thermal properties (Heat Affected Zone (HAZ)). The purpose of this research is to produce a well bonded Ni based melted powder without pores or cracks on a non-planar surface (curvilinear section). An investigation of the impact of the processing parameters, power (1500-3200 W), scanning speed (2.5-10 mm/s) and powder feeding rate (24.5-32.5 g/min) on the bonding quality, the porosity propagation and HAZ appearance is performed. The used methods are neutronography, Scanning Electron Microscopy, Energy Dispersive Spectroscopy and Electron BackScatter Diffraction (EBSD). These multi-scale techniques are obviously complementary. Neutronography is a well-adapted non-destructive method to observe the porosity in the volume thanks to the contrast between materials. EBSD analysis allows us to analyze the microstructural evolution of the coating notably by observing the dendrites growth. This same method also permits to observe the HAZ nature according to the laser cladding parameters. Those methods allowed to optimize the processing parameters in a way to obtain perfect bonding, to avoid porosity propagation and to limit the HAZ emergence