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Robust control of a high-temperature synchronous machine with anodized aluminum coils
No full textInternational audienceObjective – This paper presents a robust control strategy for wound rotor synchronous machine with anodized aluminum windings designed to operate at temperatures up to 300°C. At these high temperatures, resistance and magnetic flux can fluctuate significantly, challenging conventional control methods that depend on fixed machine parameters. This highlights the importance of a robust control strategy to effectively handle these variations.Findings – This control law has demonstrated its effectiveness in regulating machine speed and currents by enhancing the dynamics and reducing oscillations during steady-state operation. It also shows more adaptability compared to conventional control methods, such as Field-Oriented Control.Originality – Making a robust control for a high-temperature wound rotor aluminum coil machine by taking into account the losses and real-time parameters variations and estimating them. This problem is not a very present topic in the literature
Assessing Opportunity Costs Under Conflicting Objectives: Application to Profitability, Pesticide Reduction, and Crop Production
No full textThis study proposes a method to evaluate opportunity costs when shifting between competing objectives. We compare three strategies: profitability maximization (baseline), output production maximization and input cost minimization. Our analysis is conducted in two stages. First, using a log-linear production technology and incorporating output prices, we correct for inefficiencies to position all decision-making units (DMUs) on the efficiency frontier, ensuring a relevant comparison. In the second stage, we estimate opportunity costs and related price elasticity when switching strategies. Using a panel of 458 arable farms in the Meuse region (France) observed over 27 years (1991–2017), we analyze the tradeoffs between farmers’ objectives for profitability maximization, the society’s objective to maximize crop production and the environmental concern for pesticide use minimization. The first stage of analysis identifies potential improvements within each objective. In the second stage, when all practices are projected on the frontier, we compute the margin per ha loss when switching from the farmers’ objective of profitability maximization to any of the alternative scenarios and the price elasticities related to these switches. Importantly, our analysis indicates that reducing pesticide use is economically viable, while maximizing production may lead to greater financial trade-offs
Application of Ventilated Solar Façades to enhance the energy efficiency of buildings: A comprehensive review
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Biological Properties of Red Macroalgal Protein Hydrolysates and Their Uses as Biopreservatives
No full textInternational audienceIn this study, we investigate the effect of different enzyme/substrate (E/S) ratios on the antioxidant and antibacterial properties of protein hydrolysates from two unexplored red macroalgae, namely, Sphaerococcus coronopifolius (SCPH) and Gelidium spinosum (GSPH). Antioxidant properties were evaluated using DPPH radical scavenging capacity, reducing power, ferrous ion chelating ability, and total equivalent antioxidant capacity. On the other hand, antibacterial activities were evaluated using agar diffusion and minimum inhibitory concentration (MIC) methods against six bacterial strains (Listeria monocytogenes, Staphylococcus aureus, Kocuria rhizophila, Micrococcus luteus, Escherichia coli, and Salmonella newport). The biopreservative effect of SCPH and GSPH on minced meat quality during 11 days of storage at 4 °C was also studied focusing on lipid oxidation status and microbial growth. Both protein hydrolysates have considerable antioxidant activities whatever the E/S ratio used, in terms of scavenging DPPH radical (IC 50 ranging from 0.12 to 3.22 mg/mL) and metal chelating activity (IC 50 ranging from 0.15 to 2.24 mg/mL). At 5 mg/mL, the reducing power of SCPH and GSPH varied from 1.16 to 2.87. Moreover, SCPH and GSPH exhibited strong antibacterial activity against all tested bacteria, with MIC values ranging from 1.56 to 25 mg/mL. In addition, the incorporation of SCPH and GSPH into minced beef meat significantly (p < 0 05) inhibited lipid peroxidation and microbial growth during 11 days of storage at 4 °C. At the end of the storage period, the TBARS values measured in the groups treated with 1% (w/w) SCPH and GSPH were significantly reduced to 1 36 ± 0 003 and 1 34 ± 0 01 mg MDA/kg meat, respectively. Overall, the results showed that the addition of both protein hydrolysates has a positive effect on meat quality and suggest that SCPH and GSPH can serve as effective natural additives, enhancing the biopreservation and shelf life of refrigerated minced beef.</div
Intensified epoxidation of soybean oil: Evaluation and experimental optimization in a slug-flow millireactor
No full textInternational audienceThis work assessed a continuous slug-flow millireactor in the epoxidation of soybean oil with H2O2, using acetic acid as an oxygen carrier, and H2SO4 as a catalyst. The impact of the operating flow rates of the aqueous and oil phase (i.e., H2O2:oil ratio), acids to oil ratio, residence time, and temperature on reaction conversion, selectivity, yield, and productivity were experimentally evaluated. Then, an experimental simplex evolutionary optimization was conducted, and optimal operating conditions were achieved at 68.9 °C, H2O2: oil ratio of 0.79:1, acids: oil ratio of 0.29:1, and a residence time of 29.6 min. Under these conditions, conversion of 90 %, selectivity of 91 %, yield of 82 %, and a productivity of 0.95 kg OO·m−3·min−1 were obtained, reaching an oxirane oxygen content of 6.4 % wt. in epoxidized soybean oil (ESBO). While the oxirane content is slightly higher than the typically obtained using industrial reactors, the productivity is much larger. This indicates a promising potential for parallel slug-flow reactors in epoxides production
Impact of the incorporation of clove and sesame flour in the formulation of dry chicken sausages on their quality during the fermentation stage
No full textInternational audienceThis study aimed to investigate the effect of sesame flour and clove on the physico-chemical, colorimetric and structural quality of sausages during their fermentation stage. The results indicated that clove could be used as an antioxidant source in sausages produced with sesame flour. The principal component analysis (PCA) applied to the physicochemical and colorimetric data set allowed to clearly differentiate sausage samples according to the fermentation stage and, to a lesser extent, their recipes. This trend was confirmed by factorial discriminant analysis (FDA), since 97.22% of correct classification was noted. The PCA applied on the mid infrared (MIR) spectra allowed to differentiate sausage according to their formulations; this trend was confirmed by the FDA since 100% of correct classification of the samples were obtained.The partial least squares regression (PLSR) allowed a perfect prediction of the physicochemical parameters from the MIR spectra, since R2 higher than 0.85 were found for the calibration and validation model, respectively
Transporter-Mediated Interactions Between Uremic Toxins and Drugs: A Hidden Driver of Toxicity in Chronic Kidney Disease
No full textInternational audienceChronic kidney disease (CKD) is associated with the systemic accumulation of uremic toxins (UTs) due to impaired renal elimination. Among these, indoxyl sulfate (IS) and p-cresyl sulfate (PCS) are particularly challenging because of their high protein binding and limited removal by dialysis. In addition to renal excretion, the transport of IS and PCS, and their microbiota-derived precursors, indole and p-cresol, across key physiological barriers—the intestinal barrier, blood–brain barrier, and renal proximal tubule—critically influences their distribution and elimination. This review provides an overview of transporter-mediated mechanisms involved in the disposition of IS, PCS, and their microbial precursors, indole and p-cresol. It also examines how these UTs may interact with commonly prescribed drugs in CKD, particularly those that share transporter pathways as substrates or inhibitors. These drug–toxin interactions may influence the pharmacokinetics and toxicity of IS and PCS, but remain poorly characterized and largely overlooked in clinical settings. A better understanding of these processes may guide future efforts to optimize pharmacotherapy and support more informed management of CKD patients, particularly in the context of polypharmacy
Analyse de séances conçues dans le cadre d’un dispositif de formation portant sur l’usage de l’histoire des mathématiques à l’école primaire
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