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Multi-methods approach for characterizing lithium-ion batteries aged to induce lithium plating
No full textA comprehensive understanding of aging phenomena in lithiumion batteries requires advanced analytical tools. This study applies a multi-method post-mortem approach to characterize structural and chemical changes in graphite anodes from cells cycled under conditions designed to induce lithium plating. The work is part of the SUSTAIN project, which supports the development of a catalog of battery damages to enable reliable diagnostics for second-life and recycling applications.
Samples from aged and reference 18650-type cells were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Raman spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron spectroscopy (XPS), and laser-induced breakdown spectroscopy (LIBS). This combination enabled cross-validation of findings and a deeper insight into surface morphology, elemental composition, chemical bonding, and lithium distribution.
The analysis revealed two distinct degradation features on the aged anodes—a porous carbon-rich surface and a localized mossy structure—each with unique signatures across the applied methods. The results highlight how different techniques complement each other in identifying electrolyte breakdown products, structural disorders, and lithium-related changes.
This study demonstrates the value of a multi-method strategy for building a structured catalog of degradation modes, supporting condition diagnostics, and sustainable battery use
EDS with Low-Voltage SEM: Possibilities and limitations of lithium detection and quantification
No full textAchieving reliable detection and quantification of lithium (Li) with high spatial resolution down to the nanometer (nm) range is a major challenge on the path to fully understanding lithium-ion batteries throughout their life span. This paper presents possible influencing factors, such as contamination, radiation damage and charging effects, on EDS analysis, as well as methods for detecting and avoiding these effects. A windowless EDS detector specialising in the detection of low-energy X-rays enables Li content analysis. Even in Li compounds with overlapping edges, the lithium content can be clarified. The systematic investigation of the detection of lithium in lithium metal and lithium compounds, lithium batteries, and the influence of sample preparation and storage is presented. The reliability and accuracy of EDS quantification on samples under non-ideal testing conditions is also investigated. A new method of quantifying lithium, 'Li by difference', is introduced, whereby the lithium content is calculated as the missing element fraction of a non-normalised EDS quantification
Lipid profile and thermal behavior of oils extracted from Butiá's seeds
No full textThis study investigates the potential of Butiá odorata seeds, a native palm species from southern South America, as a novel and sustainable source of vegetable oil. Two types of oil, denominated Butiá almond oil (BAO) and Butiá seed oil (BSO), were mechanically extracted and characterized in terms of lipid content, fatty acid profile, triglyceride composition, and thermal behavior. Both oils exhibited high content of short and medium chain saturated fatty acids, particularly lauric and capric acids, as well a notable presence of oleic acid. Triglyceride analysis revealed a predominance of tri-saturated and di-saturated mono-unsaturated species, with low ECN values. Thermal analysis from DSC confirmed low melting points indicating typical liquid oil behavior. The properties studied suggest that Butiá oils may be suitable for food applications where rapid melting and enhanced sensory attributes are desired, and potentially for use in cosmetics, pharmaceuticals, and biofuels. Given the limited previous research, this work provides valuable data on Butiá odorata and supports its valorization within the scope of the circular economy. Further studies are recommended to optimize processing and fully explore industrial applications of these underutilized native resources
Plasma Ramp-up and Sustainment Scenarios for Tokamak Energy’s Fusion Pilot Plant
No full textTokamak Energy is designing a Fusion Pilot Plant under the US Department of Energy’s Milestone-Based Fusion Development Program. Tokamak Energy’s Fusion Pilot Plant is based on low aspect ratio tokamak with high-temperature superconducting coils, exploiting the potential to access high confinement, high beta, and high bootstrap current fraction. Representative parameters used in the present modelling are: major radius R0 = 4.25 m, aspect ratio A = 2.15, toroidal field Bt = 4.0 T, and plasma current Ip = 13.6 MA. Since the flux swing capability of the central solenoid (CS) is not sufficient to reach full Ip, a novel Ip ramp-up and sustainment scenario utilising RF power (EC and IC), bootstrap current, and induction by the CS and other poloidal field coils was developed. The plasma is initiated with EC power injected to the “trapped particle configuration”. Following initial ECCD overdrive with CS assist at low density, plasma is densified and ion heating by IC is applied to initiate fusion burn. The increased plasma stored energy drives the bootstrap current, and additional ramp-up to full Ip is achieved with inductive assist from the increasing vertical field. Optimisation of the CS usage during Ip ramp-up is essential to achieve quick Ip ramp-up with minimal use of the CS flux
How to design the perfect lecture
No full textLectures are the backbone of undergraduate physics education and are likely to remain so for the foreseeable future. This means it is important that they provide the best possible educational experience for our students. A lecture can be defined as the gathering of students (typically in large numbers) in the same place and at the same time, for a teaching event led by an expert in the subject of study. However, the exact form that a lecture takes can vary widely. It may consist primarily of a didactic monologue from the lecturer, or it may involve students doing substantial amounts of discussing and problem solving, and anything in between. This variation has been accelerated in recent decades with the use of technology offering easy access to new pedagogies, together with the introduction of flipped and active learning approaches. In this article, I will first review the evidence for what makes teaching lectures effective from the field of physics education research. I will then focus on three key elements of a lecture which should be considered in order to optimise the learning and engagement of students: interactions between teacher and students, interactions between the students in small groups and the student experience of the lecture
Ménopause, traitement hormonal et risque cardiovasculaire
No full textChez la femme, les maladies cardiovasculaires représentent actuellement la deuxième cause de mortalité en France. La période de la ménopause constitue probablement le moment idéal pour dépister l’ensemble des facteurs de risque cardiovasculaires. Cette étape diagnostique est indispensable avant de proposer l’utilisation d’un traitement hormonal de la ménopause, s’il existe une véritable indication. Si ce traitement est autorisé, l’estradiol par voie transdermique associé à la progestérone naturelle constitue le traitement qui assure la meilleure sécurité d’emploi chez les femmes n’ayant pas d’antécédent d’hystérectomie. La tolérance de ce traitement, ainsi que l’ensemble des facteurs de risque cardiovasculaires, doivent être évalués annuellement afin d’optimiser la balance bénéfice-risque de ce traitement
Machine learning-assisted prediction of thermal-hydraulic behaviour in additively manufactured microchannels using hybrid nanofluids and surface roughness correlation
No full textThis research explores the thermal and hydraulic behaviour of straight microchannel heat sinks (MCHS) fabricated using Direct Metal Laser Sintering (DMLS) and cooled with hybrid nanofluids containing Al2O3 and CuO nanoparticles. The combined use of these nanoparticles improved the fluid’s thermophysical properties, while the natural rough surfaces formed during additive manufacturing promoted passive convection. Experiments were conducted with nanofluid concentrations of 0.02% and 0.05% for Reynolds numbers ranging from 23 to 125, under heat fluxes of 20 to 40 W/cm². At a 0.05% concentration and a 30 W/cm2 heat flux, the Nusselt number increased by 12.9%, the surface temperature decreased by 13.8%, and the pressure drop rose by a moderate 6.4%. The performance evaluation criteria (PEC > 1) confirmed that the heat transfer benefit outperformed the hydraulic penalty. The experimental data were further applied to machine learning regression models, including polynomial regression, random forest, Gradient boosting and decision tree. Among them, the Gradient boosting model achieved the highest prediction accuracy, with R2 values above 0.94. The findings highlight that integrating hybrid nanofluids, additive manufacturing, and predictive modelling can lead to compact and energy-efficient cooling systems for modern power and electronic devices
Integrating renewable energy using a lecturer's office as a case study: A comprehensive approach to PV system implementation
No full textThere has been an increasing rise in the demand for an alternative source of electricity due to the effects of fossil fuels on our environment and humans. Renewable energy has been a sought-after source of energy due to its efficiency, environmental friendliness, and reliability. A small-scale implementation of a Photovoltaic system is the starting point to reducing emissions of greenhouse gases, carbon dioxide, and other unfriendly gases in the environment. Furthermore, it serves as a means of generating energy whenever there is a fluctuation or power off from the utility grid. This project demonstrates the effectiveness of PV systems through accurate load calculation and optimized component design, reducing reliance on fossil fuels, and improving the state of the environment. Data was gathered for accurate sizing of these components and monitoring after installation. A 200W solar panel, a 30A charge controller, a 200AH lithium battery, and a 1000W inverter were used in this project. Post-installation data showed solar output rising from 0.792 to 0.800 kWh, charging currents of 0.9-1.6 A, and battery discharge currents of 2.8–1.2 A with a state-of-charge drop from 100% to 85%, confirming stable performance
Strength Characteristics of Concrete Elements Having Aluminum Dross and Styrofoam Food Pack Waste as Partial Replacement of Sand
No full textThis paper investigates the feasibility of using aluminum dross and Styrofoam food-pack waste (SFPW) as partial replacements for sand in concrete. An M20-grade concrete (1:2:4 mix, w/c = 0.55) was produced with aluminum dross (5% and 7.5% by weight of fine aggregate) and SFPW (0.5-2.0%). Compressive strength (on 150 mm cubes) was tested at 7, 21, 28, 45, and 60 days, and splitting tensile strength (on 0150x300 mm cylinders) at 7, 21, and 28 days, following British Standard methods. Results show that increasing waste content reduces strength: at 60 days the control mix reached 21.8 N/mm2, whereas the mix with 7.5% dross + 2% SFPW achieved 11.6 N/mm2 (≈47% lower). The optimal waste mix (5% dross + 0.5% SFPW) had 18.2 N/rmrf at 60 days (≈17% below control). All mixes exhibited strength gain over time, but mixes with aluminum dross showed early-age setting delays and slight expansion due to hydrogen gas release. While strength and density decrease with these waste additions, the modified concrete meets non-structural strength requirements and offers environmental benefits by diverting waste. Limitations include lack of durability testing and use of relatively low replacement levels. Implications: such concrete could be used in non-load-bearing applications (e.g. masonry blocks, paving, insulation panels), contributing to sustainability by conserving sand and reusing industrial and plastic wastes
Effect of perovskite absorber thickness and working temperature on the hematite-based ETL in PSCs
No full textA key factor in increasing the efficiency of perovskite solar cell (PCSs) is optimizing the thickness of the absorber and the operating temperature. In order to examine the impact of these factors, a planar n-i-p PSCs with the configuration FTO/α-Fe2O3/MAPbI3/Spiro-OMeTAD/Au was simulated using SCAPS-1D. The results indicate that the charge carrier generation and transportation are strongly governed by the thickness of MAPbI3 absorber layer. When tune to 600 nm thickness, the device has a Jsc of 22.1 mA/cm2, an Voc of 1.06 V, a FF of 77.4 %, and an overall PCE of 18.3 %. When layers are too thin (800nm), they cause recombination losses that lower the FF. Variation in the temperature also affect how well the device works in different temperature conditions. For example, raising form 300 K to 350 K lowers the Voc and PCE because of non-radiative recombination happens more often. These finding highlight that careful control of absorber thickness coupled with thermal stability of the α-Fe2O3 ETL is crucial for achieving stable and high-efficiency PSCs