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Are hydrophilic deep eutectic solvents a potential vehicle for topical delivery of Amphotericin B against cutaneous leishmaniasis? An investigation of physicochemical properties, tolerability and antileishmanial efficacy
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Deux briques magiques hiératiques inédites au nom de Pay (Birmingham 1969 W 3573-3574)
No full textInternational audiencePublication of two unpublished hieratic magical bricks of Pay with northern and southern spells of chapter 151 of the Book of the Dead (Birmingham 1969 W 3573, 1969 W 3574), which may date from the Ramesside Period. The analysis includes remarks on the materiality of these objects and on the archaeology of ritual
« Profiter. ‘Avant de se caser’ : pourquoi hommes et femmes ne suivent pas les mêmes étapes ? »
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Relationship between scalar and electromagnetic beam shape coefficients for fields with a propagating factor of exp ( ± i β z ) : Linear and circular polarizations
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Design Optimization of Contra-Rotating Axial Flow Fan Using a SHADE-Based Approach
No full textInternational audienceContra-rotating fans are known to offer an efficient solution for applications requiring high pressure and low energy consumption. This study introduces a novel approach utilizing a metaheuristic algorithm for the optimal design of a contra-rotating axial flow fan. The geometry of the two rotors is obtained using Success-History based Adaptive Differential Evolution (SHADE) optimization algorithm and a 1D inverse design model, aiming to maximize overall hydraulic efficiency. For the optimal design, the blade cross-section between the hub and tip of the two rotors must comply with geometric constraints defined by the limitations of NACA65-type airfoil cascade. To achieve the desired nominal pressure rise, a sequential optimization strategy is proposed. First, the front rotor is optimized, and then the rear rotor is optimized based on the results from the front rotor, including parameters such as hub and tip radius, velocity triangles, and others. The optimal geometry is analyzed over a range of flow rates using loss models and computational fluid dynamics (CFD) software. The results show a high performance for the contra-rotating geometry obtained by the proposed approach, with a wide operating range. At design point, relative to the existing fan in literature, the proposed fan achieves a 5% efficiency improvement and a 4% higher pressure rise than the specification, whereas the reference fan exhibits a 12% deficit
Microscale stored energy as a fatigue indicator for NiTi shape memory alloys via synchrotron X-ray diffraction
No full textInternational audienceAlthough fatigue is closely related to microstructural changes, current fatigue criteria for shape memory alloys (SMAs) fail to account for this information due to the lack of research on quantifying microstructural defects associated with fatigue. In this study, we introduce local stored energy as a quantifiable parameter that reflects microstructural evolution and demonstrate its effectiveness as a reliable fatigue indicator. Ex-situ synchrotron X-ray diffraction tests were conducted on a series of NiTi specimens subjected to cyclic loading and stopped at different fatigue stages. The results revealed inhomogeneous microstructures along the gauge section, characterized by residual R-phase accumulation, defect density, and residual stress in active zones. These microstructural changes, resulting from localized deformation, were quantified by local stored energy at the microscale via X-ray peak analysis. Consistent with these inhomogeneous microstructures, the distribution of local stored energy was uneven, with maximum values in active zones where fatigue cracks preferentially occur. As fatigue progressed, local stored energy in these zones increased, eventually stabilizing at a steady state. This steady state exhibited a negative correlation with fatigue lifetimes, where higher loading frequencies resulted in increased stored energy and shorter lifetimes. These findings validate local stored energy as a crucial fatigue indicator, paving the way for development of a physically-grounded fatigue criterion based on this quantity
Reduced order modelling for shell finite element structures using the direct parametrisation of invariant manifolds: Hardening/softening transition, resonant dynamics and mode selection
No full textInternational audienceThe accurate simulation of the nonlinear dynamics of thin-walled structures is a critical but computationally demanding task. In this contribution, a 7-parameter solid-shell finite element formulation is combined with the direct parametrisation method for invariant manifolds (DPIM), in order to derive accurate and efficient reduced-order models (ROM) accounting for geometric nonlinearity. The method is illustrated in its ability to be used with different yet complementary purposes. On the one hand, low-order tractable models can be obtained, providing simple ROMs that are amenable to giving physical insights and understanding. On the other hand, higher-order solutions are available within the same framework, hence providing accurate and converged solutions. This scheme is carried out on examples with increasing complexity. First, the transition from hardening to softening behaviour for thin shells with shape imperfections is investigated. The 1:2 resonance as a driver of the change of type of nonlinearity is analysed, and a full understanding of the smooth transition is illustrated. Then, shells with varying thicknesses are investigated, and the case of 1:2 internal resonance is further investigated, showing the emergence of isolated solution branches (isola). In the course of the numerical simulations, it is shown how the reduced basis needs to be enlarged to take into account more and more complex resonance scenarios, and some guidelines are provided in order to help the analyst in selecting the master modes. The numerical results highlight the ability of the reduced-order models to provide a fully comprehensive and integrated framework for the understanding and accurate prediction of thin shells' nonlinear dynamics
Methodological insights into the dip-and-pull X-ray photoelectron spectroscopy technique: analysing electrochemical interfaces under in situ/operando conditions
No full textInternational audienceGaining insight into structural and compositional transformations occurring at the electrode/electrolyte interface during the operation of electrochemical systems is fundamental to understanding and, thus, optimizing their performance. Such an analysis must be performed in operando conditions, owing to the potential, electrolyte and time dependence of these transformations. Here, the use of X-ray photoelectron spectroscopy (XPS) is particularly attractive due to its surface sensitivity and ability to provide quantitative information on the oxidation state and chemical environment of an element. In specific instrumental configurations [ e.g. in `dip-and-pull' (D&P) or `meniscus' setup], it can be used to analyse not only the electrode but also the electrolyte side of the interface, under in situ / operando conditions. In this article, we discuss how D&P XPS can provide unique information on both sides of the electrode/electrolyte interface, briefly review publications demonstrating its capabilities, highlight the challenges the method faces, and share our views on its future developments. This article aims to provide a practical guide to new D&P synchrotron users and help them to understand the technique, and physical phenomena that may impede the acquisition of reliable data
