7 research outputs found

    Transposition of a weighted ah-throughput model to another li-ion technology: is the model still valid? new insights on the mechanisms

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    The increasing interest in electric vehicles powered by rechargeable batteries, combined with the wide development of powerful lithium-ion batteries as a renewable energy storage system have raised the need for battery ageing characterization. Several models have been developed for this purpose, including empirical, fatigue and mathematical ones. One of the main issue of these approaches consists of the universality, when extension is required to other chemistries or solicitations. Electrochemical models are supposedly the most extensible. The Weighted Ah-Throughput Model takes into account that certain operating conditions may lead either to an increase or a decrease of the rate of ageing. It modulates the impact of the exchanged Ah by the temperature, the C-rate and the state of charge (SOC), both in calendar and active regime. This influence of the parameters is described here, and compared between two Li-ion chemistries: LFP and NCA. The similitudes enable us to extract the generic hidden mechanisms that, by nature, the fatigue modelling methods do not provide. This innovative method enables us to reach energetic behavior laws. We finally suggest improvements on the tests matrix used to define the model, to better fit the outcome of the study

    Thermo-mechanical behaviour of a compacted swelling clay

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    Compacted unsaturated swelling clay is often considered as a possible buffer material for deep nuclear waste disposal. An isotropic cell permitting simultaneous control of suction, temperature and pressure was used to study the thermo-mechanical behaviour of this clay. Tests were performed at total suctions ranging from 9 to 110 MPa, temperature from 25 to 80 degrees C, isotropic pressure from 0.1 to 60 MPa. It was observed that heating at constant suction and pressure induces either swelling or contraction. The results from compression tests at constant suction and temperature evidenced that at lower suction, the yield pressure was lower, the elastic compressibility parameter and the plastic compressibility parameter were higher. On the other hand, at a similar suction, the yield pressure was slightly influenced by the temperature; and the compressibility parameters were insensitive to temperature changes. The thermal hardening phenomenon was equally evidenced by following a thermo-mechanical path of loading-heating-cooling-reloading

    Transposition of a weighted ah-throughput model to another li-ion technology: is the model still valid? new insights on the mechanisms

    No full text
    The increasing interest in electric vehicles powered by rechargeable batteries, combined with the wide development of powerful lithium-ion batteries as a renewable energy storage system have raised the need for battery ageing characterization. Several models have been developed for this purpose, including empirical, fatigue and mathematical ones. One of the main issue of these approaches consists of the universality, when extension is required to other chemistries or solicitations. Electrochemical models are supposedly the most extensible. The Weighted Ah-Throughput Model takes into account that certain operating conditions may lead either to an increase or a decrease of the rate of ageing. It modulates the impact of the exchanged Ah by the temperature, the C-rate and the state of charge (SOC), both in calendar and active regime. This influence of the parameters is described here, and compared between two Li-ion chemistries: LFP and NCA. The similitudes enable us to extract the generic hidden mechanisms that, by nature, the fatigue modelling methods do not provide. This innovative method enables us to reach energetic behavior laws. We finally suggest improvements on the tests matrix used to define the model, to better fit the outcome of the study

    Blood Gene Expression Predicts Bronchiolitis Obliterans Syndrome

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    Bronchiolitis obliterans syndrome (BOS), the main manifestation of chronic lung allograft dysfunction, leads to poor long-term survival after lung transplantation. Identifying predictors of BOS is essential to prevent the progression of dysfunction before irreversible damage occurs. By using a large set of 107 samples from lung recipients, we performed microarray gene expression profiling of whole blood to identify early biomarkers of BOS, including samples from 49 patients with stable function for at least 3 years, 32 samples collected at least 6 months before BOS diagnosis (prediction group), and 26 samples at or after BOS diagnosis (diagnosis group). An independent set from 25 lung recipients was used for validation by quantitative PCR (13 stables, 11 in the prediction group, and 8 in the diagnosis group). We identified 50 transcripts differentially expressed between stable and BOS recipients. Three genes, namely POU class 2 associating factor 1 (POU2AF1), T-cell leukemia/lymphoma protein 1A (TCL1A), and B cell lymphocyte kinase, were validated as predictive biomarkers of BOS more than 6 months before diagnosis, with areas under the curve of 0.83, 0.77, and 0.78 respectively. These genes allow stratification based on BOS risk (log-rank test p < 0.01) and are not associated with time posttransplantation. This is the first published large-scale gene expression analysis of blood after lung transplantation. The three-gene blood signature could provide clinicians with new tools to improve follow-up and adapt treatment of patients likely to develop BOS

    Airway microbiota signals anabolic and catabolic remodeling in the transplanted lung

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