Search Results (3,423)

The management of organic waste in high-altitude mining poses a distinctive circularity challenge: waste is generated at sites decoupled from agricultural systems, while the same operations are legally required to revegetate the land they disturb. This study provides, to the best of our knowledge, the first primary-data environmental characterization of a real system that valorizes dining-facility organic waste from a high-altitude mining unit in northern Peru into a solid biofertilizer and a liquid biol, both applied in situ for land reclamation. Unlike methanogenic digesters, the system operates under a lactic (acidogenic) fermentation regime inoculated with effective microorganisms and does not recover biogas. A cradle-to-gate life cycle assessment (ISO 14040/14044) with Monte Carlo uncertainty propagation was combined with a well-established family of five circular economy indicators, adapted to the non-energy-recovery case by redefining the Energy Self-Sufficiency Ratio (ESSR) and the Decarbonization Circularity Indicator (DCI). The principal contribution is methodological: the framework is extended to a circularity archetype that previous, biogas-centered formulations could not represent, showing that a system can close its material and nutrient loops robustly (WVI = 0.97) while the energy loop is absent by design (ESSR = 0). The climate result is conditional and is a first-order greenhouse-gas (GHG) screening balance, not a physical carbon-sequestration claim: under the upper-bound assumption of full fertilizer substitution, the avoided fertilizer credit outweighs non-methane process emissions only below a narrow fugitive-methane threshold (≈0.32 kg CH${}_4$ per ton), a margin that narrows further once agronomic equivalence is discounted. The measured product acidity suggests that this condition is plausible, but, because methane was not measured directly, the low-emission interpretation is presented as a hypothesis requiring confirmation rather than as a demonstrated result. The environmental burden is driven by material and electricity inputs—chiefly the polypropylene containers and grid electricity—rather than by the biological process, which broadens the set of improvement priorities beyond methane management to include capital-good reuse and electricity decarbonization, without implying that methane can be neglected. Full article

This study evaluated the efficacy of post-extraction American cockroach (Periplaneta americana) residue (PAR) as a dietary feed ingredient on the growth performance, antioxidant defense, and whole-body amino acid profile of juvenile black carp (Mylopharyngodon piceus). A total of 300 juvenile black carp (initial weight 17.19 ± 0.20 g) were fed five isonitrogenous and isolipidic diets for 64 days. PAR was supplemented at inclusion levels of 0% (control), 5%, 10%, 15%, and 20% (corresponding to progressive reductions in dietary fishmeal). The results showed that fish fed the diet with 5% PAR inclusion maintained growth performance and feed conversion efficiency comparable to those of the control group (p > 0.05). Thus, 5% PAR did not significantly improve growth performance, but it did not impair growth under the present experimental conditions. Moreover, 5% PAR supplementation significantly increased hepatic catalase activity and was associated with numerically higher values of several other antioxidant- and immune-related indices. PAR inclusion also increased whole-body glycine deposition, whereas high inclusion levels reduced whole-body methionine content and crude protein deposition. Dietary PAR inclusion at higher levels, especially 20%, was associated with a possible reduction in feed utilization, altered organ indices, altered serum glucose levels, suppressed hepatic transaminase activities, and changes in digestive enzyme activities. However, these responses should be interpreted as the combined outcome of ingredient substitution, amino acid imbalance, altered lipid source, possible essential fatty acid changes, chitin/fiber-like fractions, and metabolic burden, rather than as effects of chitin alone. In conclusion, 5% PAR may be a suitable practical inclusion level for juvenile black carp under the present experimental conditions, whereas excessive inclusion should be used with caution and may require amino acid balancing, improved processing, and further evaluation of dietary gross energy, fatty acid profile, and chitin content. Full article

The rapid expansion of hydrogen technologies has intensified the demand for platinum group metals (PGMs), particularly platinum (Pt) and iridium (Ir). Proton exchange membrane fuel cells (PEMFCs) and proton exchange membrane water electrolyzers (PEMWEs) rely on PGMs and fluoropolymer membranes such as Nafion, generating increasing volumes of end-of-life (EoL) membrane electrode assemblies (MEAs). Conventional recycling routes are often energy-intensive, hazardous and limited in polymer recovery. In this study, a closed-loop hydrometallurgical recycling route is assessed through a life cycle assessment (LCA), supported by primary experimental data from optimized recycling trials. Mechanical delamination enabled separation of catalyst layers while preserving membranes, followed by a chlorine-based hydrometallurgical process operating under mild conditions. Leaching efficiencies exceeded 99% for Pt and 80% for Ir, demonstrating the feasibility of metal recovery. Two LCA models were developed: (i) a gate-to-gate recycling model for EoL MEAs and (ii) a cradle-to-gate manufacturing model comparing virgin and recycled Pt. Results showed that substituting virgin Pt with recycled Pt reduced the global warming potential of MEA manufacturing by up to 70%. The analysis also identified electricity demand and Nafion membrane waste as key environmental hotspots. Overall, the study highlights the potential of closed-loop recycling to enhance circularity in hydrogen technologies. Full article

Subterranean metro stations require substantial structural material inputs and can generate prolonged disruption in dense urban environments. Rather than assessing the environmental performance of an entire metro system, this study compares the embodied environmental impacts and surface-occupation effects of two representative underground station typologies from the Istanbul M7 Metro Line: a deep Top-Down station and a shallower Cut-and-Cover station. The proposed SECURE framework integrates Building Information Modelling (BIM)-based Life Cycle Assessment (LCA) with a Spatiotemporal Disruption Index (SDI), which is used as a physical proxy for cumulative surface occupation during construction. The assessment covers material production, transport, end-of-life processes, and recovery benefits in accordance with ISO 14040/14044, while excluding operational energy and on-site construction machinery from the comparative LCA boundary. The results show that the deep Top-Down typology requires 3.11 m³/m² of structural concrete, compared with 2.22 m³/m² for the Cut-and-Cover typology. Within the analysed cases, this higher structural material intensity is associated with a 54% increase in Global Warming Potential, from 9953.62 to 15,343.14 kg CO₂ eq/m². The difference primarily reflects the combined influence of excavation depth, station geometry, reinforced concrete volume, and permanent retaining elements, rather than the construction sequence alone. In contrast, the Top-Down typology substantially reduces modelled surface occupation, with cumulative SDI decreasing from 115,800 to 45,675 m²·month. These findings indicate a trade-off between embodied environmental burden and potential socio-spatial disruption. The study therefore suggests that early-stage metro station planning should evaluate excavation depth, structural mass, construction sequence, and surface continuity together. For deep urban stations where Top-Down construction is required, low-carbon cement substitution and localised material sourcing may help reduce material-related environmental impacts. Full article

This study investigated the effects of partial substitution of diesel fuel with hydrogen in dual-fuel operation on the engine operating characteristics, energy performance, and exhaust emissions of a compression-ignition passenger car engine. Hydrogen was supplied into the intake manifold, and the vehicle was tested on a chassis dynamometer at a constant vehicle speed under varying load conditions. To avoid the onset of abnormal combustion, the maximum stable H₂ mass fraction under diesel–hydrogen dual-fuel operation had to be reduced from 19% to 11% as engine load increased over the brake mean effective pressure (BMEP) range of 0.38–0.88 MPa, while the corresponding H₂ volume fraction in the intake air increased from 4.2% to 6.3%. Hydrogen addition reduced diesel fuel consumption and CO₂ emissions, although its effect depended strongly on engine load. At a 10% H₂ mass fraction, diesel fuel consumption decreased by 20–25%, and CO₂ emissions decreased by 17–21%. At low load, hydrogen addition improved brake thermal efficiency (BTE) and reduced NO_x emissions. At higher loads, reaching the hydrogen flammability limit reduced the excess-air ratio, deteriorated diesel combustion quality, and increased NO_x emissions and the exhaust smoke absorption coefficient. Higher H₂ concentrations reduced combined NO_x + HC emissions at low load but increased them at medium and high loads. Overall, hydrogen enrichment was most effective at low and medium loads, below the abnormal combustion onset limit, indicating that load-sensitive hydrogen dosing is required for efficient and environmentally favourable diesel–hydrogen dual-fuel operation. Full article

The transition towards climate-neutral metallurgical production requires a broader transformation than the simple substitution of fossil-fuel combustion with electrical heating. While process electrification is a fundamental step towards reducing greenhouse gas emissions, achieving truly sustainable high-temperature processing also depends on the ability to maintain tightly controlled reaction environments, minimise thermal losses, and maximise the efficient use of process gases. These factors become increasingly important as the industry moves towards hydrogen-assisted processing routes and greater integration of renewable energy sources. By controlling heat transfer and gas composition, a stable processing environment can be maintained in which temperature, and gases’ partial pressure, can be accurately regulated throughout the treatment cycle. This study introduces the engineering concept of an airtight electrified indirect-fired rotary furnace, developed as a new process for efficient calcination, and also, hydrogen-based reduction processes. To assess the applicability of the proposed reactor concept, a bench-scale experimental campaign was carried out using two representative metallurgical processes: magnesite calcination and hydrogen-assisted reduction of lateritic ores. Throughout the testing campaign, the reactor maintained stable thermal conditions and a well-controlled process atmosphere, while the integrated monitoring system enabled continuous observation of temperature evolution and gas composition. The calcination trials achieved conversion efficiencies above 98%, whereas the hydrogen-reduction experiments successfully promoted the transformation of iron and nickel oxide phases into their metallic state. The results demonstrate that the integration of indirect electrical heating with airtight reactor operation provides a robust platform for hydrogen-assisted thermal processing. The proposed architecture improves atmosphere control and process efficiency while offering a scalable solution for the future implementation of electrified, low-carbon metallurgical technologies. Full article

This study systematically investigates the effects of gold tailings (GT) sand substitution levels and particle fineness on the rheological behavior, mechanical properties, and microstructural characteristics of Engineered Cementitious Composites (ECC). The results demonstrate that incorporating moderate amounts of GT sand (≤75%) effectively enhances both the compressive strength and fracture toughness of the composite. However, complete substitution (100% GT) significantly increases matrix porosity, leading to a consequent reduction in comprehensive mechanical strength. A critical size-dependent decoupling effect was observed: while the full replacement of fine aggregates with coarse GT severely degrades compressive strength due to excessive void formation, it unexpectedly increases the matrix fracture toughness by inducing significant crack deflection and tortuosity. Conversely, the incorporation of fine GT optimizes the distribution of matrix flaws and fosters a stable fiber pull-out mechanism. Consequently, despite a reduced pseudo-strain hardening (PSH) index, the fine GT-blended ECC achieves a remarkable tensile ductility of up to 3.0% by satisfying the fundamental multiple-cracking energy criteria while maximizing frictional energy dissipation. Furthermore, substituting natural silica sand with GT yields a highly sustainable composite, reducing carbon dioxide emissions by 41% and material costs by 20% without compromising core mechanical performance. Full article

Although the acute phase of the SARS-CoV-2 pandemic has subsided, the continued emergence of viral variants underscores the need for structurally diverse antiviral inhibitors. In this study, molecular docking followed by molecular dynamics (300 ns) simulations and binding free energy calculations using the Molecular Mechanics Poisson–Boltzmann Surface Area (MM-PBSA) method were employed to evaluate substituted flavonoids derived from Taraxacum officinale and Urtica dioica as potential inhibitors of the SARS-CoV-2 main protease (Mpro/3CLpro). Docking analysis identified several derivatives with favorable binding scores; however, dynamic refinement revealed differential stability among the ligand–protein complexes. Among the evaluated compounds, the luteolin derivative LND-17 showed the most consistent performance, exhibiting binding free energy estimates approaching those obtained for the reference inhibitors nirmatrelvir and ensitrelvir, sustained catalytic pocket occupancy, and energetic contributions involving the catalytic dyad (His41 and Cys145). Additional derivatives, including LNG-04, QND-07, and QNG-20, showed moderate stabilization but lower overall consistency. These findings highlight glycosylated flavonoids as promising scaffolds for future structure-based optimization and provide structural insights to guide experimental validation. Full article

Doping provides an effective means to tailor the chemical properties of clusters and construct novel functional materials. However, the specific effects of rare-earth doping on the structural evolution and electronic properties of semiconductor clusters remain unclear. To address this, we systematically investigated the structures, growth patterns, electronic properties, and spectroscopic characteristics of Ge_n⁻ and LaGe_n^0/− clusters (n = 10–20) using the ABCluster global search method combined with the mPW2PLYP double-hybrid density functional. Notably, the global minimum (GM) structures of Ge_n⁻ (n = 12–20), confirmed based on calculated energies and measured photoelectron spectroscopy data, differ from previously reported structures. Starting from n = 12, the GM structure of the Ge_n⁻ cluster can be considered as formed by attaching an additional Ge_(n–9) or Ge_(n–10) subcluster to a capped tetragonal antiprism Ge₉ (or dicapped tetragonal antiprism Ge₁₀) subunit. The evolution pattern of LaGe_n (n = 10–19) clusters can be viewed as substitutional structures, in which a La atom substitutes one Ge atom in the Ge_(n+1)⁻ cluster. At n = 20, a cage-like structure is formed. For LaGe_n⁻ (n = 10–19), when n = 10–12 and 18, the structures are linked configurations, where the La atom connects two Ge subclusters. For the remaining clusters, although their global minimum structures tend toward linked configurations, they are fundamentally substitutional in nature. The GM structure of LaGe₂₀⁻ is an encapsulated configuration, with the La atom encapsulated at the center of the Ge cage. The average binding energies, relative stabilities, and HOMO–LUMO energy gaps of the clusters were evaluated. The photoelectron spectra of LaGe_n⁻ (n = 10–20) and the UV–vis absorption spectrum of the LaGe₂₀⁻ cluster were simulated. The results demonstrate that the LaGe₂₀⁻ superatom cluster with high Ih symmetry exhibits favorable optical properties, along with excellent chemical and thermodynamic stability, suggesting its potential as a promising building block for further exploration in optoelectronic-related applications. Full article

The cement industry is one of the most challenging sectors to decarbonize due to the coexistence of high-temperature thermal demand and process-related emissions from limestone calcination. This study presents an energy and emissions assessment of cement manufacturing based on representative mass and energy balances derived from literature benchmarks and industrial operating data. Typical cement production requires 2.8–3.6 GJ of thermal energy and 80–120 kWh of electricity per tonne of final product, resulting in total emission in the range 500–850 kg CO₂/t cement, of which 55–65% originate from clinker calcination. Moving from this baseline, possible decarbonization pathways are evaluated, including energy efficiency improvements, clinker substitution through supplementary cementitious materials use of alternative fuels, electrification, hydrogen utilization and carbon capture technologies. The analysis shows that energy efficiency measures provide relatively limited reductions (10–30 kg CO₂/t cement), while alternative fuels and clinker substitution can achieve larger but still partial benefits. Hydrogen emerges as a promising option for decarbonizing the combustion-related share of emissions, with a potential reduction ranging from 50 to 200 kg CO₂/t cement, particularly when integrated with oxy-fuel combustion systems. Deep decarbonization ultimately requires carbon capture and storage (CCS), the only technology capable of addressing the substantial process emissions inherent to clinker production and use of hydrogen can be relevant too. Full article

As the scale of renewable energy integration continues to expand, the uncertainty and variability of power system operation has increased. Meanwhile, peak regulation resources have become increasingly diverse, making the formation of peak regulation costs more complex. Existing allocation mechanisms therefore have difficulty directly linking the temporal power profile of each entity to its contribution to the optimized deep peak regulation cost and the corresponding cost responsibility. This paper applies the standard Shapley value framework to deep peak regulation cost allocation involving multiple peak regulation demand entities. An energy-preserving substitute scenario method is applied to heterogeneous demand entities. The actual profiles of coalition members are retained, whereas the profiles of nonmembers are replaced by their mean values, thereby removing temporal fluctuations while preserving total energy over the dispatch horizon. For each coalition-specific net load scenario, a dispatch optimization model considering the piecewise deep regulation capability of thermal units and the intertemporal constraints of pumped storage are re-solved, and the resulting minimum cost is used to construct the coalition cost function. The signed Shapley value is then used to calculate the average marginal cost effect of each entity across all coalitions, after which a practical positive contribution settlement rule converts the signed values into nonnegative and budget-balanced charges. A provincial system case study shows that, compared with energy proportional and peak power proportional allocation, the proposed method explicitly accounts for the temporal characteristics and interactions of heterogeneous power profiles and links them to changes in the optimized deep peak regulation cost through coalition-specific re-optimization. Full article

Clutch length is a key determinant of egg production in geese and has a direct impact on breeding efficiency. However, the genetic and molecular mechanisms underlying variation in clutch length remain largely unclear in Zi geese. In this study, we integrated whole-genome resequencing with ovarian transcriptomic and proteomic analyses to identify candidate genes and functional single nucleotide polymorphisms (SNPs) associated with clutch length. A total of 200 female Zi geese were monitored throughout a 230-day laying period, from which 20 individuals with the longest clutch length and 20 with the shortest clutch length were selected for multi-omics analyses. Comparative analyses identified 424 differentially expressed genes and 856 differentially expressed proteins between the two groups. Integration of population-differentiated SNPs, genome-wide association study signals, transcriptomic, and proteomic datasets converged on two key candidate genes, INHA (inhibin subunit alpha) and FNDC1 (fibronectin type III domain containing 1). INHA expression was negatively associated with clutch length, whereas FNDC1 expression showed a positive association. Eight missense SNPs were detected across these two genes. Notably, structural modelling and molecular docking analyses demonstrated that the Gly10Cys substitution in INHA markedly increased the binding affinity of INHA homodimerisation (binding energy: −10.4 kcal/mol versus −8.6 kcal/mol for the wild-type protein), promoting the formation of more stable but functionally inactive INHA–INHA homodimers. This finding provides a plausible molecular explanation for the reduced INHA mRNA and INHA protein expression observed in geese with longer clutch lengths. These structural analyses suggest that the biological effects of these identified missense SNPs are primarily mediated through protein conformational changes. Collectively, our findings identify INHA and FNDC1 as key regulators of clutch length in Zi geese and reveal a previously unrecognised structural mechanism by which an INHA missense variant may influence reproductive performance. These results provide valuable molecular markers and mechanistic insights for the genetic improvement of egg production in geese. Full article

Introduction: Restrictive diets are increasingly encountered in pediatric practice and may be adopted voluntarily or prescribed for medical conditions. Although they can support normal growth when appropriately planned, exclusion of nutritionally important foods may increase the risk of nutrient inadequacy. This narrative review examined nutritional deficiencies and laboratory monitoring in children following plant-based, food-allergy elimination, gluten-free, ketogenic, and protein-restricted diets for inherited metabolic disorders. Methods: Targeted searches of PubMed, Scopus, and Web of Science were conducted through 30 June 2026 using pediatric, diet-specific, nutritional-status, and biomarker terms. Because this was a narrative review, the literature was selected and synthesized qualitatively rather than through a formal systematic-screening process; no fixed study count, duplicate independent screening, or formal risk-of-bias assessment was performed. Professional guidelines and position papers were prioritized when discussing monitoring considerations, while pediatric studies were used to describe dietary intake, biochemical findings, clinically manifest deficiency, and growth outcomes. Results: Nutritional risks differed according to the foods or nutrients restricted. Vitamin B12 and iron were major concerns in plant-based diets, whereas cow’s milk and multiple-food elimination increased the risk of inadequate calcium, vitamin D, iodine, protein, and energy intake. Gluten-free diets were commonly associated with low fiber, iron, folate, and B-vitamin intake, particularly when refined, non-fortified products predominated. Ketogenic dietary therapy required attention to selenium, vitamin D, bone-related minerals, carnitine in selected patients, and linear growth. In phenylketonuria and related disorders, nutritional adequacy depended strongly on protein-substitute adherence and appropriate provision of essential amino acids and micronutrients. Across all dietary patterns, laboratory results required interpretation in relation to dietary intake, growth, supplementation, inflammation, medication, and the underlying condition. Across dietary patterns, inadequate intake, biochemical abnormalities, clinically manifest deficiency, and impaired growth were considered related but distinct outcomes. Conclusions: Nutritional monitoring should be individualized and based on the actual dietary restriction and clinical risk. The principal contribution of this review is a practical, risk-based framework that links the specific dietary restriction and adequacy of replacement foods with growth, symptoms, supplementation, and targeted laboratory biomarkers. Full article

Background: Energy dissipation reflects the viscoelastic behavior of biological tissues and plays a key role in arterial elastic recoil and diastolic flow support. In the native aorta, efficient storage and release of mechanical energy are essential for maintaining ventriculo–aortic coupling. The energy dissipation ratio (EDR) quantifies the proportion of mechanical energy lost during a loading–unloading cycle and may provide insight into the biomechanical performance of aortic substitutes. Bovine pericardial patches (BPPs) are widely used in cardiovascular surgery for arterial reconstruction, patch angioplasty, and tubular replacement. Today, EDR has not been systematically investigated in BPPs. Methods: Forty glutaraldehyde-treated BPPs from four commercial manufacturers (n = 10 per supplier) were subjected to low-cycle fatigue testing using a uniaxial tensile system under controlled physiological conditions (37 °C). Standardized bone-shaped specimens were tested at progressive strain percentage levels. Thickness, EDR, and the percentage of specimens failing to reach progressively higher strain levels were evaluated from stress–strain hysteresis loops. Results: BPPs thickness ranged from 0.253 to 0.608 mm, with no significant differences among most groups. For the 10% strain, all BPPs reached the target deformation and demonstrated comparable EDR values. In detail, the mean EDR was 21.40 ± 7.02% for Edwards Lifesciences, 24.95 ± 6.80% for Supple Peri-Guard (Baxter), 24.99 ± 6.04% for Xenosure (LeMaitre), and 23.37 ± 6.12% for Invengenx–Tisgenx, with no statistically significant intergroup differences (p > 0.05). For the 20% strain, only 18.75% of specimens remained structurally intact, and variability increased. At 30% strain, structural failure occurred in nearly all samples. No significant orientation-dependent differences were observed. Conclusions: Commercially available BPPs exhibit similar biomechanical behavior under moderate deformation. However, tolerance to higher strain is limited. EDR analysis provides a clinically relevant parameter to assess elastic performance and may contribute to optimizing aortic substitute selection. Full article

The decarbonization of passenger transport remains one of the most challenging sectors for climate policy, as supply-side technological solutions alone are insufficient to meet stringent climate targets. This paper presents an extended system dynamics model of the Spanish passenger transport sector, built on the WILIAM integrated assessment framework, that for the first time endogenizes modal shift, allowing transport mode shares to emerge from the interaction of policy instruments, price signals, and infrastructure provision. Four scenarios are evaluated to 2050: a Baseline, a scenario calibrated to the Spanish National Integrated Energy and Climate Plan (GG-PNIEC), a more ambitious electrification and modal-shift scenario (GG+), and a Decent Living Standards scenario (DLS) combining technological change with deep demand reduction. Relative to 2023, direct CO₂ emissions in 2050 fall by 64% under GG-PNIEC, 75% under GG+, and 84% under DLS. While GG-PNIEC and GG+ deliver substantial reductions through electrification, only DLS approaches deep decarbonization, combining rapid electrification with a reduction of over 55% in light-duty vehicle travel demand relative to the Baseline. These results indicate that technological substitution alone is insufficient, and that sufficiency-oriented demand reduction is decisive for reaching the deepest emission cuts in passenger transport. Full article