Hal - Université Grenoble Alpes
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Un port de plaisance n’est pas un hôtel (obs. sous CE, 23 déc. 2025, n° 503613, Assoc. Cap Nautique La Rochelle et a.)
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Nemo plus juris, censetur ignorare legem, et coetera (obs. sous Cass. civ. 3, 18 déc. 2025, Mme D. c./ Dpt de l'Hérault, n° 24-20.480)
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Terahertz Imaging of Early Stage Thermal Transformations in Oil Shale
No full textInternational audienceThe characterization of oil shales is essential for evaluating their quality and industrial potential. Existing techniques, such as X-ray tomography (XCT), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM–EDS), infrared (IR) and Raman spectroscopies, and nuclear magnetic resonance (NMR), provide valuable information. However, none of these methods offer millimetric/sub-millimetric-scale resolution with direct sensitivity to simultaneous changes in both water and organic matter within a bulk sample. To address this limitation, terahertz (THz) imaging has previously been applied to oil shales; however, no studies have explored its use under varying temperature conditions of the sample. This is particularly relevant, as heating the samples at low temperatures (<200 °C) can provide new insights into their structural and compositional evolution. Thus, in this work, we acquired THz images after sequential heating an oil shale sample at 40, 150, and 200 °C for 15 h each, in order to monitor its change during thermal evolution. The results revealed, for the first time, changes in the THz images arising from the evaporation of free water, the release of bound water from clays, and transformation of organic matter. These findings were validated and explained by complementary analyses, including X-ray diffraction (XRD), XCT, and Rock-Eval pyrolysis. Furthermore, a first effective absorption and refractive index model was proposed, which enabled the estimation of free and bound water evaporation
Porous NaTi<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub>-PVDF Composite Granules as Negolyte Boosters for Sodium-Based Redox-Targeting Flow Batteries
No full textInternational audienceRedox-Targeting Flow Batteries (RTFBs) are promising alternatives to classical vanadium-based batteries for large-scale and stationary energy storage. Typically, RTFBs are marked by higher energy densities thanks to the addition of solid boosters within aqueous systems, taking care to limit the use of critical raw materials. This work subsequently investigates the case of sodium titanium phosphate (NTP, NaTi2(PO4)3, 132.8 mAh/g) as a potential booster material for the negolyte side of aqueous RTFBs. Pure NTP and carbon-coated NTP (C-NTP) particles were synthesized and characterized by various techniques (X-ray, TEM, TGA, Raman). So-obtained NTP and C-NTP particles were found to be suitable for creating innovative porous composite boosters formed as centimeter-sized granules by dry processing. Porous composite granules with an open porosity of 65% and 50 wt % of immobilized NTP or C-NTP were successfully produced by an extrusion–dissolution process using a regular PVDF binder and PEO as a porogen agent. Subsequently, intensive electrochemical tests were performed using an innovative dual-mediator reaction system (Fe-Tiron and 2,7-AQDS). High NTP reactivity, with booster utilization rates of up to 84% of its theoretical capacity, can be achieved under flow conditions, with an increase in volumetric capacity by a factor of 1.5, from 4 Ah L–1 to 6 Ah L–1. The mediator concentration (10 – 100 mM) and the mediator/booster ratio (0.5 – 1) play key roles in NTP reactivity. The fundamental work also highlights the benefit of C-NTP, allowing higher reactivity at low mediator concentrations. The study consequently validates the potential of NTP as an interesting booster material in future RTFB applications, with its scalable extrusion–dissolution technique to create innovative porous booster granules
A multi-model ensemble and its portability for the prognostics of direct methanol fuel cells under different dynamic operating conditions
No full textInternational audienceAccurate estimation of State Of Health (SOH) and prediction of RemainingUseful Life (RUL) are all-important to ensure the fuel cells' reliable operation.During the ageing of Direct Methanol Fuel Cells (DMFCs), the output voltage can be monitored in real-time to acquire the degradation trend. However, traditional prognostic methods relying solely on observed voltage trend regression cannot cope with dynamic changes in operation. The deep-level degradation information, which is merely affected by environmental factors, can be accessed by the Electrochemical Impedance Spectroscopy (EIS) measurements. Using the Equivalent Circuit Model (ECM), degradation covariates such as internal impedances can be identified and tracked over time. This paper proposes an approach that combines internal characterization and direct observation to predict the RUL of DMFCs under dynamic operating conditions. The proposed approach is implemented on two DMFCs of the same type prepared for accelerated ageing tests under different scenarios: one DMFC following the China Light Vehicle Test Cycle (CLTC) for training, and the other following the World Light Vehicle Test Cycle (WLTC) to verify the method’s portability. Compared to the traditional data-driven prediction method, experimental results show that the proposed multi-level degradation indicator-based approach can provide more accurate SOH estimation and RUL predictions.</p
Modeling the Vibrational Circular Dichroism Spectroscopy of Phenylcyclohexanediol Solvated in Dimethyl Sulfoxide Using Polarizable Molecular Dynamics
No full textInternational audienceModeling vibrational circular dichroism (VCD) spectra in solution remains a complex task due to the intricate interactions involved. Recent advances in computational chemistry, particularly the implementation of polarizable force fields, have greatly improved the description of environmental effects in classical molecular dynamics simulations. In this study, we use the AMOEBA polarizable model to calculate VCD spectra through the expression of the electric and magnetic dipole moments developed recently [Bowles J. et al. ChemPhysChem 2024, 25, e202300982] in combination with the use of induced dipole models. This methodology enables the reliable treatment of flexible molecules and has been applied to the 1-Phenyl-1,2-Cyclohexanediol (PC) molecule in dimethyl sulfoxide (DMSO). The computed infrared and VCD spectra provide detailed insights into molecular conformations and solute-solvent interactions. An in-depth investigation was conducted into the possible effects of system size, concentration, and spectral convergence. Comparison with experimental vibrational frequencies in deuterated solvent further supports the interpretation of spectral features, although residual differences in the spectral shifts and broadenings prove to be challenging for theory, especially in the case of VCD.</div
A nationwide 12‐month observatory of automated insulin delivery shows improved glucose control, sustained adoption, and reduced acute severe events
No full textInternational audienceAims: A nationwide observational study was conducted to assess the 12-month effectiveness of AID systems in the routine care of people with Type 1 diabetes (PwT1D).Methods: All PwT1D, adults, and children, who initiated AID between January 1, 2022, and December 31, 2022, were included across 79 centres. Clinical data, continuous glucose monitoring (CGM) parameters, acute severe events in the last year, and HbA1c levels were collected at AID initiation, and after 3, 6, and 12 months of AID treatment. Median values [interquartile range, IQR] and % PwT1D with acute severe events were reported. The primary outcome was the change in time in range (TIR; 3.9-10 mmol/L) after 1 year with AID.Results: A total of 2741 PwT1D were included: 44.4% male, age 38 years [29], BMI 24.5 kg/m2 [6.7], diabetes duration 19 years [20]. AID systems were MiniMed 780G in 49.7%, Tandem Control-IQ in 49.3%, others in 1%. After 12 months, TIR increased from 58.0 [21] to 70.1% [14] while HbA1c levels decreased from 7.6 [1.2] to 7.0% [0.8]. Percent PwT1D experiencing severe hypoglycaemia (SH) decreased from 4.1 to 0.9%, and ketoacidosis from 1.2 to 0.6%. All improvements were observed after 3 months, sustained through 12 months, and statistically significant (p < 0.05). Only 2.8% of PwT1D discontinued AID.Conclusions: Twelve months of AID use in routine care improved glucose control in PwT1D, among whom there was less experienced SH and a minor discontinuation
