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A comparative study of BiFeO<sub>3</sub>-based compounds for enhanced hydrogen evolution reaction
No full textInternational audienceWe present a comprehensive study, combining experimental and theoretical approaches, to assess the hydrogen evolution reaction (HER) efficiency of BiFeO3-based solid solutions. Initially, we investigate the electronic and optical properties of these compounds, with a particular focus on band edge alignment relative to water redox potentials. Our findings show that the materials exhibit optimal band gaps of approximately 2.0 eV, indicative of enhanced visible light absorption and favorable energetic alignment to drive efficient hydrogen generation. To corroborate our theoretical predictions, we perform photoelectrochemical measurements on selected BiFeO3-based compounds synthesized via the solid-state method. Our experimental results reveal a high hydrogen yield, with BiFeO3-SrTiO3 achieving a production rate of ∼114 µmol/L in 30 min, outperforming BiFeO3-BaTiO3 (∼70 µmol/L) and pristine BiFeO3 (∼61 µmol/L). These findings validate our theoretical assumptions and demonstrate the superior HER performance of BiFeO3-SrTiO3, positioning it as a highly promising candidate for sustainable hydrogen production
Physicochemical, nutritional and structural properties of mealworm powders manufactured by using different technological processes
No full textInternational audienceDue to the growing concerns over the sustainability of traditional protein sources, edible insects such as Tenebriomolitor (T. molitor) are gaining attention as promising alternatives, offering high nutritional value and a lowerenvironmental footprint. The present study aimed to evaluate the impact of pre-treatment processes on thequality of T. molitor powders derived from: i) fresh freeze-dried larvae flour (FDF), ii) whole (undefatted)blanched and dried larvae flour (WUF), and iii) partially defatted, blanched, pressed, and dried larvae flour(PDF). Significant differences (P < 0.05) were observed among the three powders in terms of physico-chemicalcomposition, color attributes, and technofunctional properties. For instance, the highest protein content wasfound in PDF powder (61.7 %), followed by WUF (52.9 %) and FDF (51.4 %) powders. The FDF powder exhibitedthe highest brightness (L* = 46.9) and browning index (BI = 76.4). PDF powder demonstrated superior functionalperformance, with the highest oil holding capacity (2.1 g oil/g powder), swelling capacity (2.7 mL water/gpowder), and water holding capacity (2.7 g water/g powder). These macroscopic changes were corroborated bystructural differences observed at the molecular (fluorescence spectroscopy and FT-MIR) and microstructural(scanning electron microscopy) levels. Overall, the findings highlight the critical influence of processing onT. molitor powder quality, with potential implications for its use in food and feed applications
Impact of acidic and basic pH on the interfacial shear rheology and foaming properties of transglutaminase cross-linked casein micelle: Structure-function relationship
No full textInternational audienceThis work investigated the pH effect (pH 3.5 to 9.0) on the interfacial behavior of native and transglutaminasecross-linked (TGase) caseins films at air-water interface using a rotational rheometer equipped with a BiConegeometry. Both caseins formed a viscous-like interfacial adsorbed layer within the range of frequency from 0.1 to10 rad/s, with a maxima viscoelastic layer at alkaline pH (8.0 and 9.0). TGase caseins exhibited the highestinterfacial shear surface moduli values, and the difference between them was pronouncedly, under acid pHconditions (3.5 to 5.5). The conformational studies revealed the pH and transglutaminase cross-linking effect onthe protein structure. The foaming properties suggested a weakening and strengthening of foaming capacity andstability, respectively, by TGase in alkaline pH conditions. The combination of pH-shifting and transglutaminasetreatment, especially, under alkaline p
Determination of antibacterial and antioxidant potential of organic crude extracts from Malus domestica, Cinnamomum verum and Trachyspermum ammi
No full textInternational audiencePlants are the rich source of biologically active compounds which can be obliging against various pathogenic microorganisms and cancerous diseases. The current study evaluated the antibacterial potential of aqueous, methanol, ethanol, and acetone extracts of Malus domestica (apple), Cinnamomum verum (cinnamon) and Trachyspermum ammi (ajwain) via agar well diffusion methods and minimum inhibitory concentration (MIC) in (mm) against Staphylococcus aureus (ATCC 25923) and Salmonella typhi (ATCC 19430). The antioxidant properties including total phenolic content (TPC), total flavonoid content (TFC), DPPH and reducing power was determined by UV/VIS spectrophotometery and all the results interpreted through one way ANOVA (STATISTICA). In the results, methanolic and acetonic extracts of C. verum has shown maximum zone of inhibition (22.3 ± 0.58 mm) against S. aureus while for C. verum and T. ammi, ethanolic extracts has expressed the maximum zone of inhibition (22.3 ± 0.58 mm) against S. typhi and for M. domestica the methanolic extracts has exhibited highest zone of inhibition (18 ± 0.56 mm) among all other extracts of M. domestica. The MIC values were comparable with antimicrobial activity. Among the antioxidant activity analysis, the highest level of TPC has observed in aqueous extract of M. domestica 72.15 ± 1.80 mg GAE/g, while highest TFC was observed in methanolic extracts of M. domestica 15.62 ± 0.25 µg CE/g. The DPPH assay showed maximum percentage inhibition 123% in the methanolic extract of M. domestica, while highest reducing potential 13.42 ± 1.15 nm was observed in aqueous extract of C. verum. This study has compared three potential medicinal plants with biological active and eco-friendly components which play crucial role in therapeutics
CSR Performance and Firm Value: Disentangling the Role of ESG Rating Providers
No full textInternational audienceWe study the impact on firm valuation of a novel exogenous shock to environmental, social, and governance (ESG) data that affects how firms’ corporate social responsibility (CSR) gets measured by a third‐party ESG data provider. Our analysis reveals a significantly higher sensitivity of firm values to CSR ratings for firms whose CSR ratings were affected by the change in ESG reporting methodology. Moreover, firms with low capital constraints or low institutional ownership tend to drive the value sensitivity of CSR ratings when ESG reporting gets revamped. These findings provide insight into how ESG rating providers could influence and shape firms’ actual CSR engagement
Une intermédialité claudicante : creux créatif et art raté dans La caída de Madrid et Los viejos amigos de Rafael Chirbes
No full textInternational audienceEn los dos últimos volúmenes de la trilogía chirbesiana, La caída de Madrid (2000) y Los viejos amigos (2003), los diversos aspectos de la práctica artística -creación, colección o exposición -suelen verse marcados por la fatalidad del fracaso. Semejante hueco creativo se representa bajo dos formas particulares de encarnación del arte fallido: la imposibilidad de acceder al medio artístico y, más sutilmente, la práctica interesada del arte, entonces considerado como una mercancía, lo que le quita toda sinceridad al proceso creativo o exposicional. Se trata entonces de darse cuenta de que el significado de tal inexorabilidad del fracaso se relaciona con la agria denuncia de la dictadura de las apariencias que consigue socavar el mundo artístico, en su sentido más amplio, en la sociedad española del tardofranquismo y de la Transición. Sin embargo, la práctica del arte se ve rehabilitada felizmente en las diégesis cuando tiene lugar en la intimidad, señal de su realización según un espíritu de autenticidad. La operatividad de las referencias artísticas no se restringe al mero nivel intraficcional sino que alcanza también el de los lectores, conducidos a interpretar las remisiones intermediales que lucen los textos como claves de comprensión diseminadas por toques a lo largo de las dos novelas. Por ende, es según el modo de la claudicación como funciona la intermedialidad en los dos últimos opus de la trilogía de Chirbes, en que las artes oscilan entre situaciones de fiasco y de eficiencia.Dans les deux derniers volumes de la trilogie chirbésienne, La caída de Madrid (2000) et Los viejos amigos (2003), les divers pans de la pratique artistique -création, collection ou exposition -se trouvent très régulièrement marqués par la fatalité de l'échec. Un tel creux créatif est représenté sous deux formes particulières d'incarnation de l'art raté : l'impossibilité d'accéder au milieu artistique et, plus subtilement, la pratique intéressée de l'art, alors considéré comme une marchandise, ce qui ôte toute sincérité à la démarche créative ou expositionnelle. Il s'agit alors de se rendre compte que la signification de cette inexorabilité de l'échec a trait à l'âpre dénonciation de la dictature des apparences qui en vient à miner le monde artistique au sens large dans la société espagnole du franquisme tardif et de la Transition. Toutefois, la pratique de l'art se voit heureusement réhabilitée dans les diégèses lorsqu'elle a lieu dans l'intimité, signe de sa réalisation dans un esprit d'authenticité. L'opérativité des références artistiques ne s'arrête pas au niveau intrafictionnel, mais atteint également celui des lecteurs, amenés à interpréter les renvois intermédiaux dont se parent les textes comme des clés de compréhension disséminées par touches au fil des deux romans. C'est ainsi sur le mode de la claudication que fonctionne l'intermédialité dans les deux derniers opus de la trilogie de Chirbes, où les arts vacillent entre situations d'insuccès et d'efficience
Navigating the legal environment of AI (part 2)
No full textIESEG Insights. https://insights.ieseg.fr/en/resource-center/navigating-the-legal-environment-of-ai-part-2
Constructing gender through reporting: unveiling the rhetorical strategies of an NGO from 1995 to 2021
No full textInternational audiencePurpose Addressing grand challenges requires an in-depth understanding of the social constructs, such as the gender discourse that shapes gender equality. Accounting, through annual reporting, contributes to constructing realities, thus impacting grand challenges. This paper explores how organizational reporting by a non-governmental organization (NGO) promotes particular ideologies about gender in a changing sociocultural context. Design/methodology/approach The paper uses a case study of an NGO that has long used annual reports to disseminate its perspectives on gender. Drawing on 1,251 pages of annual reports (in French, a gendered language), including 1,618 visuals, from 1995 to 2021, we use feminist and ideological perspectives to analyse the rhetorical strategies used. Findings The results show that the NGO’s annual reports include evolving perspectives on gender. In an earlier period, it emphasizes complementarity between men and women while assigning primary roles to men. More recently, while the organization continues to support traditional visions on gender representation, the reporting narratives and visuals strive towards greater inclusivity. The findings also suggest instances of ambiguity in how an organization can use narratives and visuals, prompting a discussion on the idea of rhetorical ambiguity in organizational reporting. Originality/value This study shows how organizational reporting longitudinally evolves regarding grand challenges, beyond financial and business matters. The paper identifies sites of gender ideology in both visuals and narratives of the reports
Temporal dynamics and tidal influences on plastic deposition, remobilization, and accumulation in an estuarine mixing zone in Northern France
No full textInternational audiencePlastic pollution represents a critical threat to estuarine environments, with the complex dynamics of plastic deposition, remobilization, and accumulation remaining understudied. This study investigated these three processes in a natural French estuary during semi-diurnal tidal cycles, focusing on the influence of these cycles, wind patterns, and substrate types. Repeated samplings were conducted at regular intervals, with six consecutive observations during low tides each month over a period of 3 months. OSPAR protocol along a 100 m2 transect was used, and plastic deposition rates ranged from 1.5 ± 0.54 plastics/100 m2 to 31.16 ± 8.06 plastics/100 m2 per semi-diurnal tide cycle. Remobilization rates varied from 50 to 100%, with substrates such as mud and gravel showing rapid remobilization and low accumulation, while dense vegetation retained up to nine times more plastic, acting as hotspots for accumulation. In addition, landward winds amplified this plastic deposition, increasing rates by a factor of 5 to 20, particularly during spring tides. Macroplastics dominated the various sizes of plastic deposited, and polymer analysis identified polyethylene and polypropylene as the most prevalent polymers. Long-term monitoring underestimated plastic retention by a factor of up to 20, highlighting the value of short-term, high-frequency observations to accurately study plastic dynamics. These results reveal the complex interaction of substrate characteristics, environmental factors, and tidal cycles in the regulation of plastic dynamics in estuarine environments and the need for targeted mitigation strategies to protect these ecosystems