Electric Arc Furnace Dust (EAFD) is a hazardous byproduct of steelmaking that poses significant environmental and regulatory challenges due to its toxic-metal content, while also representing a strategic secondary resource within circular-economy frameworks aimed at reducing primary raw-material extraction and waste disposal. This critical review evaluates current and emerging EAFD valorization pathways—including hydrometallurgical, pyrometallurgical, and hybrid routes—through an integrated sustainability perspective that combines environmental performance, techno-economic feasibility, product-market integration, and governance considerations. Rather than providing a purely technological comparison, the analysis systematically examines key sustainability indicators such as energy, water, and reagent consumption per tonne of EAFD; emission profiles (CO₂, liquid and solid effluents); material recovery efficiencies; and secondary residue generation, alongside logistical constraints related to transport, product specifications, and downstream market demand. Particular emphasis is placed on the role of EAFD valorization in mitigating environmental liabilities, enhancing industrial symbiosis, and supporting resource-efficiency strategies at regional and global scales. The review further examines interactions among waste generators, technology providers, end-users, and policymakers, highlighting regulatory, technological, and market-related barriers that currently limit large-scale implementation, and ultimately proposes a decision-oriented framework to guide the sustainable and circular recovery of valuable metals from EAFD. Provides a sustainability-oriented comparison of EAFD valorization pathways. Integrates environmental, techno-economic, market, and governance perspectives. Identifies key circular economy barriers beyond purely technological limitations. Assesses the circular performance of hydrometallurgical, pyrometallurgical, and hybrid routes. Proposes a decision-oriented framework for sustainable EAFD recovery.
This study examines whether management control systems (MCS) mediate the relationship between governance mechanisms and the maturity of environmental, social, and governance (ESG) practices in organizations. Using survey data from 142 Brazilian firms and partial least squares structural equation modeling (PLS-SEM), the results indicate that governance mechanisms are not directly associated with the level of ESG maturity. Instead, their effect is fully transmitted through the use of management control mechanisms, such as strategic planning, budgeting, forecasting, and performance monitoring, that operationalize strategic intentions and translate them into organizational action. From a theoretical perspective, the study integrates governance and management control literatures by empirically examining how governance mechanisms are associated with ESG maturity through internal management control mechanisms. Empirically, the findings highlight the mediating role of MCS and demonstrate that governance is associated with ESG maturity only when activated through coherent planning and control mechanisms (full mediation model). The results carry important implications for managers, boards, and policymakers seeking to advance ESG integration, particularly in institutional contexts characterized by weak or evolving legal mandates for boards. ESG initiatives progress not through isolated governance structures, but when sustainability intentions are embedded within an integrated set of planning and control mechanisms. By shifting the analytical focus from formal governance structures to execution and internal coordination, this study contributes to a more actionable understanding of how sustainability practices become institutionalized in organizational behavior.
Epoxy-based thin films reinforced with graphene oxide (GO), hexagonal boron nitride (h-BN), and their hybrid combination (GO/h-BN) at low filler contents (< 1 wt%) were developed to advance thermosetting nanocomposites for high-performance thermal interface materials (TIMs). The incorporation of these 2D nanostructures led to marked and simultaneous increases in both the storage modulus (E ') and the glass transition temperature (T-g) for the individual and hybrid systems. These enhancements indicated strong interfacial interactions between the nanofillers and the epoxy matrix, promoting a more efficient crosslinking density and reinforcing the overall rigidity of the polymer network. Uniform thin films, processed under controlled conditions, exhibited efficient phonon transport without compromising their dielectric integrity, as demonstrated by steady-state and 3-omega thermal analyses. The incorporation of 0.5 wt% GO/h-BN resulted in up to a 56% enhancement in thermal conductivity at 90 degrees C while preserving the intrinsic thermal stability of the epoxy system. These synergistic effects yielded multifunctional nanocomposites that combine high thermal conductivity, superior mechanical reinforcement, and electrical insulation, positioning them as promising candidates for next-generation TIMs in advanced electronic and photonic applications.
PurposeThis study aims to explore how central bank digital currencies (CBDCs) reshape the geopolitics of monetary sovereignty by shifting authority from private-led to state-driven payment infrastructures. It argues that sovereignty in monetary affairs must be understood not only as the legal prerogative to issue currency but also as control over the technological and institutional systems that underpin cross-border payments and settlements.Design/methodology/approachThe study analyses two cases: the Bank for International Settlements Innovation Hub's mBridge project and the embryonic, largely symbolic BRICS Cross-Border Payments Initiative. It builds on scholarship in currency hierarchies and infrastructural geopolitics to assess how these proposals may transform the geopolitical dynamics of payment infrastructures.FindingsThe cases show that CBDCs can incrementally reconfigure power within an international monetary system long anchored in US dollar dominance and Western-centric private utilities such as the Society for Worldwide Interbank Financial Telecommunication, the New York Clearing House Interbank Payments System and Continuous Linked Settlement. mBridge demonstrates how public governance can be embedded directly into code, contracts and consensus protocols, while BRICS highlights the symbolic projection of infrastructural autonomy.Research limitations/implicationsThe findings suggest that although CBDCs can expand monetary sovereignty through infrastructural redesign, they also expose persistent structural constraints within the international monetary system. Moreover, US dollar dominance may be deeply connected to factors beyond payment infrastructures, such as global liquidity provision, the depth of US financial markets and strong network effects, which CBDCs alone may not overcome.Originality/valueThe study contributes by demonstrating that CBDCs function as infrastructural interventions with potential implications for geopolitics, while also linking debates on technological design to broader questions of monetary sovereignty.
Stellar photospheric heterogeneities (e.g., starspots and faculae) distort the apparent stellar spectrum during a transit and imprint wavelength-dependent biases on the measured planet–to–star radius ratio. This transit light source effect (TLSE) must be accounted for to obtain reliable atmospheric properties. A widely used approach is the Rackham–TLSE (R–TLSE) prescription, which applies a disk-averaged contamination correction based solely on the filling factor and spectral contrast. However, accurate transmission-spectroscopy interpretations require models that also account for limb darkening, the spatial distribution of active regions, and transit geometry. In this work, we incorporated these effects into a self-consistent, pixel-resolved framework, ECLIPSE-Xλ, and performed idealized, noise-free model–model comparisons against the R–TLSE approximation. Using three archetypal systems – the super-Earth LHS 1140 b, the mini-Neptune K2-18 b, and the hot Jupiter WASP-69 b – we show that disk-averaged TLSE corrections can differ from the self-consistent model by up to ~400 ppm in the optical for active hosts and non-equatorial transits, while remaining below ~10 ppm at near-infrared wavelengths where limb darkening is weaker. We then applied both approaches to the JWST/NIRISS SOSS transmission spectrum of LHS 1140 b. When limb darkening is artificially set to zero, ECLIPSE-Xλ recovers stellar-contamination parameters that closely match the reference R–TLSE solution, confirming that the two frameworks are consistent in the disk-averaged limit. With wavelength-dependent limb darkening included, however, reproducing the observed short-wavelength slope through stellar contamination alone requires very hot faculae (ΔTfac ≃ 600 K) covering ffac ≃ 0.35 of the visible hemisphere, corresponding to an equivalent circular facular region with radius ≃0.6 R⋆ (i.e., about 60% of the stellar radius) on the stellar disk. Such an extended, unocculted active region would be physically unlikely even for an active M dwarf. In this context, a purely stellar-contamination explanation for any residual optical slope would demand rather extreme facular populations; scenarios in which a genuine atmospheric contribution helps complement a more modest facular signal appear more physically plausible. Taken together, these results delineate the regime of validity of the R–TLSE approximation and underscore the need for geometry-aware stellar-heterogeneity models that explicitly account for limb darkening in high-precision transmission spectroscopy.
