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The stationary version of the Boussinesq system with a general gravitational acceleration term is considered. Under suitable assumptions on this term, as well as on the external forces acting on each equation of this coupled system, we first establish the existence of weak solutions in the natural energy space H˙1(R3). The uniqueness of these solutions is a challenging open problem. Within this framework, our first main contribution is to show that any weak H˙1-solution exhibits an analytic smoothing effect in the Gevrey class. Our second main contribution is to show that the Gevrey class regularity can also be used to study the uniqueness problem, provided that these solutions satisfy a suitable low-frequency control. As a by-product, we also obtain new regularity results and a new Liouville-type result for weak H˙1-solutions of the classical Navier–Stokes equations.
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Mine tailings (MTs) limit plant and microbial establishment due to low fertility, poor structures, and toxic metal(loid) contents. Organic amendments (OAs) modify these conditions by increasing contents of carbon and nutrients and decreasing metal(loid) toxicity; however, the overall effectiveness of OAs remains unclear. This meta-analysis evaluated the effects of OAs on the chemical and biological properties of MTs. A total of 2322 observations from 47 studies were analyzed. Application of OAs increased total and available contents of N, P, Ca, Mg and total organic carbon (TOC) by 50–300
This study analyzes the influence of direct carbon emissions (Scope 1), those emitted indirectly through energy consumption (Scope 2), and those occurring within the value chain (Scope 3) on corporate profit margin (measured as net income-to-assets ratio, with ROA as robustness check), examining the dual moderating roles of environmental regulation and sectoral heterogeneity. Using a fixed-effects panel model on a sample of 250 global companies from the Forbes Global 2000 Lists for 2020–2023, we find a significant negative association between emissions volume and financial performance. This economic impact is particularly pronounced in the chemical and utilities sectors, whereas the oil and gas sectors exhibit atypical dynamics, characterized by resilience. Contrary to expectations, cross-country regulatory stringency does not significantly moderate this relationship. The findings, subject to the specific temporal and regulatory scope analyzed, suggest that sectoral structural factors appear more consistently associated with emissions-profitability variation than measured regulatory stringency, providing preliminary evidence consistent with the importance of industry-specific approaches to decarbonization.
Valorization of copper slag has become an essential focus in the circular economy, and its industrial exploitation represents a promising strategy to close material cycles and reduce waste generation. Thus, various reductants have been used to reduce slags; however, hydrogen stands out as the most promising owing to its ability to reduce greenhouse gas emissions in these reduction reactions, thereby contributing to a lower carbon footprint. Therefore, it is necessary to understand how hydrogen acts as a reductant; consequently, this work analyzes the effects of temperature, gas composition, and flux addition on hydrogen-assisted copper slag reduction to maximize iron recovery. Additionally, a kinetic study was conducted to understand the reaction mechanism and the process efficiency. The analysis of apparent reaction rates revealed that both a higher hydrogen concentration (30 versus 5
