Search Results (1,315)

Ammonia, as a hydrogen carrier and carbon-free alternative fuel, shows great potential in future low-carbon energy systems. This study uses dimethyl ether (DME) as a combustion promoter for ammonia to enhance the combustion performance of ammonia-fueled engines. To address the issue of unburned ammonia emissions, the original combustion chamber geometry was optimized by removing the squish area to enhance flame propagation. At an ammonia energy ratio (AER) of 60%, the modified combustion chamber (MCC) reduces unburned ammonia (uNH₃) emissions by up to 85.46% and improves indicated thermal efficiency (ITE) by 1.93% compared to the original combustion chamber (OCC). Furthermore, to achieve higher thermal efficiency and lower pollutant emissions, the DME injection strategy was redesigned based on the MCC. The results show that adjusting the single injection timing (SIT) and injection angle (INA) of DME can effectively improve the homogeneity of the in-cylinder combustible mixture and enhance combustion efficiency; however, overly concentrated injection can lead to rapid heat release and increase the risk of knock. The split injection strategy enables more controllable combustion phasing, significantly reduces the maximum pressure rise rate (MPRR) and ringing intensity (RI), and mitigates knocking tendency. When the main injection timing (MIT) is −5 °CA ATDC, pilot injection timing (PIT) is −30 °CA ATDC, and the pilot injection ratio (PIR) is 60%, the ITE reaches 49.98%, which is 3.53% higher than that of the pure diesel mode. Greenhouse gas (GHG) and NO_x emissions are reduced by 45.94% and 62.49%, respectively, with uNH₃ emissions as low as 4.16 g/kW·h. Full article

Hydrogenation reactors are critical equipment in the petrochemical industry, yet their material degradation is governed by coupled multi-mechanism damage. Current assessment practices largely neglect this complexity, remaining single-factor oriented and overlooking synergistic interactions and temporal evolution. This paper proposes a regionally differentiated, multi-level framework integrating 5 primary and 17 secondary indicators with a hybrid AHP-EWM weighting strategy that synthesizes expert knowledge and measured data. A multi-factor coupling correction coefficient is introduced to provide a preliminary estimate of the synergistic acceleration effect among damage mechanisms, while a GM(1,1) gray model enables dynamic trend prediction. Applied to a 25-year 2.25Cr-1Mo steel reactor, the method produces regional degradation values of 0.378, 0.607, and 0.533 for the base metal, welds, and cladding layer, respectively, with an overall baseline of 0.453 rising by 11% to 0.503 after coupling correction. Compared with exponential regression, ARIMA, and BP neural networks, GM(1,1) is selected for its balanced performance in small-sample fitting, extrapolation stability, and physical interpretability. Sensitivity analysis confirms stable degradation grading even with ±50% coupling coefficient variations. The proposed approach mitigates the underestimation inherent in conventional single-mechanism assessments and offers a quantitative tool for full-lifecycle risk management and predictive maintenance of hydrogenation reactors. Full article

Rising temperatures and the occurrence of heat waves due to climate change can increase the risk of various skin disorders. Moreover, elevated temperatures worsen oxidative damage and inflammation caused by other climate change stressors, such as UV exposure. Consequently, there is growing interest in innovative solutions to protect skin health from the effects of pollution and climate change stressors. Among natural cosmeceuticals, carotenoids are recognized for their antioxidant and anti-inflammatory properties. This study evaluated the thermoprotective effects of Hematococcus lacustris (the microalga formerly called Hematococcus pluvialis) extract (HLE), which is considered the richest natural source of carotenoid astaxanthin, against acute hyperthermia, which mimics the conditions of heat waves. In addition, we separately assessed the effects of HLE against UVA and hydrogen peroxide stress, complementing the antioxidant profile of the extract under study. The evaluation was conducted using in vitro tests on human HaCaT keratinocytes and the nematode Caenorhabditis elegans, which is a model organism sensitive to environmental stressors. The treatment of HaCaT keratinocytes with HLE counteracted the intracellular formation of reactive oxygen species and cytotoxicity induced by hyperthermia, UVA, and hydrogen peroxide exposure. Under the same experimental conditions, HLE also restored the impaired expression of stress-sensitive genes, such as matrix metalloproteinase-1, in HaCaT keratinocytes and promoted wound closure mimicking the process of re-epithelization. Lastly, experiments in C. elegans confirm that HLE reduces heat stress-induced oxidative damage and preserves motility, supporting a systemic protective effect consistent with dietary uptake of the extract. These findings suggest that HLE, rich in carotenoid astaxanthin, can protect keratinocytes against oxidative damage and cytotoxicity induced by thermal stress, indicating its potential role in mitigating thermal aging. Full article

Corn stover (CS), as a major agricultural residue in Northeast China, suffers from inefficient anaerobic digestion (AD) due to its rigid lignocellulosic structure and the generation of inhibitory phenolic compounds during pretreatment. Alkaline hydrogen peroxide (AHP) disrupts lignocellulosic structures while generating methanogenesis-inhibiting phenolic compounds. Current pretreatments only resolve either lignocellulosic rigidity or phenolic toxicity, with no integrated method to mitigate both simultaneously. This work investigated a combined strategy of AHP pretreatment coupled with MnO₂ amendment to improve methane production from CS using laboratory-scale batch AD. Results demonstrated that 3% AHP pretreatment induced structural modifications and altered lignin-related functional groups, while the subsequent addition of 1.0 g MnO₂ significantly (p < 0.05) removed up to 28.4% of the generated total phenolic equivalents and alleviated volatile fatty acid (VFA) accumulation. The Mn-AHP group achieved the highest cumulative methane production of 449.28 ± 13.25 mL/g VS, representing a 14.6% increase compared to the control and a 3.24% improvement over the AHP-only group. Microbial analysis revealed increased relative abundance of acidogenic bacteria (e.g., Synergistota) and a compositional shift in the archaeal community toward a structure dominated by Methanobacterium and Methanothrix. These findings indicate that coupling AHP with MnO₂ is a promising approach to address the dual challenges of lignocellulosic recalcitrance and phenolic inhibition, providing a feasible pathway for agricultural waste valorization. Full article

The imperative to mitigate climate change has accelerated the development of Carbon Capture, Utilization, and Storage (CCUS) technologies, particularly CO₂ hydrogenation into high-value chemicals and alternative fuels. This work evaluates the fundamental thermodynamic limitations and the primary directions of CO₂ conversion, with a primary focus on methanation, alongside related pathways such as methanol synthesis and the reverse water-gas shift (RWGS) reaction. To overcome the high kinetic barriers of CO₂ activation, various catalytic systems are analyzed. While noble metal catalysts exhibit high catalytic performance, nickel-based catalysts serve as a viable and cost-effective alternative. To overcome nickel’s susceptibility to thermal sintering and coking, advanced bimetallic and multimetallic formulations are being developed to enhance structural stability and selectivity. These advancements are crucial for producing Synthetic Natural Gas (SNG) and sustainable aviation fuels (SAF). Ultimately, the objective of this comprehensive review is to systematically summarize recent advancements in catalyst design, critically analyze the advantages and fundamental bottlenecks of distinct catalytic systems, and outline prospective paths for the efficient industrial-scale production of sustainable alternative fuels. Full article

Aqueous zinc-ion batteries (AZIBs) have garnered extensive attention owing to their high theoretical capacity, cost-effectiveness, and intrinsic safety. However, the practical deployment of AZIBs is severely hindered by deleterious side reactions, including surface corrosion, hydrogen evolution, and uncontrollable dendrite growth on the metallic Zn anode. In this work, we propose a simple one-step immersion strategy to in situ construct a ZnMoO₄ (ZMO) protective coating on the Zn electrode. Mechanistically, the ZMO layer with polar surfaces exhibits a preferential adsorption affinity towards water molecules and Zn²⁺ ions. This synergistic adsorption behavior serves a dual function: it effectively excludes active water from the electrode surface to suppress hydrogen evolution, and simultaneously, the strong interaction with Zn²⁺ lowers the desolvation energy barrier, facilitating rapid Zn²⁺ desolvation at the interface. Furthermore, the resulting ZMO coating promotes a homogenized surface electric field and provides abundant nucleation sites, thereby guiding uniform Zn deposition and effectively mitigating dendrite formation. Consequently, the ZMO-modified Zn anode delivers significantly enhanced electrochemical reversibility and long-term cycling stability. This work provides a cost-effective and industrially viable surface engineering strategy to tackle the fundamental challenges of Zn anodes, paving the way for the commercialization of high-performance AZIBs. Full article

Melatonin (MT), a potent antioxidant, can mitigate abiotic stress. The objective of this study was to determine if foliar spraying of MT can alleviate the stress of Trichosanthes kirilowii seedlings under drought conditions. The results showed that drought stress significantly inhibited the growth of T. kirilowii seedlings, whereas exogenous MT alleviated this inhibition. Compared with the treatment with drought stress alone, the addition of MT significantly increased the stem length, net photosynthetic rate, chlorophyll content, maximum photochemical efficiency, and relative leaf water content of T. kirilowii seedlings after 20 days of drought stress. Under drought stress, the addition of MT significantly reduced the levels of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), and reduced electrolyte leakage (EL) in the leaves of T. kirilowii seedlings. Compared with the control group, the antioxidant enzyme activity was significantly enhanced under drought stress, and the contents of soluble sugars (SSs) and proline (Pro) increased significantly. The antioxidant enzyme activity was strongest in the group treated with MT, and the SS and Pro contents were the highest in this group. The results indicate that the addition of MT can maintain the relative water content (RWC) of the leaves of T. kirilowii seedlings under drought stress, significantly enhance antioxidant capacity, reduce drought-induced damage, maintain the stability of the photosynthetic system, and promote the growth of T. kirilowii seedlings. Full article

Given that large-scale storage and transportation of liquid hydrogen are key to realizing the hydrogen economy, tank containers have attracted much attention for their flexibility. To minimize evaporation losses, efficient support structures are essential for these liquid hydrogen tank containers. Herein, a carbon fiber-reinforced polymer (CFRP) suspension ring is developed to support the inner vessel of liquid hydrogen tank containers. By using a special resin matrix and optimizing its curing process, the suspension ring capitalizes on a small cross-sectional area and low thermal conductivity, thereby significantly mitigating the cold-bridge heat transferred from the outer vessel to the inner vessel. Experimental results demonstrate that the tensile strength, outgassing rate, and fatigue performance of the suspension ring at both 77 K (liquid nitrogen temperature) and 4 K (liquid helium temperature) can meet the design targets. Notably, its equivalent thermal conductivity was approximately 88% lower than that of a stainless steel structure of the same size. With the integration of this suspension ring into a 40 ft liquid hydrogen tank container, the daily liquid nitrogen evaporation rate was recorded below 0.082%/d. Furthermore, the holding time before the pressure reached 0.14 MPa exceeded 192 h with a 90% liquid hydrogen filling ratio. This work provides key technical support for high thermal insulation, long-endurance liquid hydrogen storage and transportation equipment. Full article

The reduction in aviation-induced climate impacts requires not only decreasing CO₂ emissions, but also mitigating non-CO₂ effects such as persistent contrail cirrus. Alternative propulsion systems and fuels are therefore discussed as potential pathways toward climate-neutral aviation. However, their influence on contrail formation and evolution remains insufficiently understood, particularly regarding how emission characteristics translate into contrail microphysical behavior and lifetime. This study aims to bridge this knowledge gap by systematically evaluating the contrail-forming potential of Sustainable Aviation Fuel (SAF) and hydrogen-based propulsion systems, with a clear focus on identifying the key emission parameters that govern contrail persistence. To assess the impact of reduced particle emissions on contrail evolution, scenarios with lower initial ice crystal number concentrations $N_{\mathrm{ice}}$, representative of alternative propulsion concepts, were simulated using a Gaussian plume contrail evolution model. The results demonstrate that high ice crystal number concentrations ($N_{\mathrm{ice}}\approx {10}^{14}$–${10}^{15}$ kg⁻¹), characteristic of kerosene and many SAF combustion cases, lead to persistent contrails with lifetimes of approximately 9–12 h due to suppressed crystal growth and sedimentation. Conversely, low initial ice crystal concentrations ($N_{\mathrm{ice}}\approx {10}^9$–${10}^{10}$ kg⁻¹), expected for hydrogen systems under aerosol-limited nucleation conditions, promote short-lived contrails in the order of minutes. The findings indicate that contrail impacts are influenced not only by the fuel type itself, but also by combustion processes, atmospheric conditions, and the prevailing nucleation mechanisms. Consequently, the potential of SAF and hydrogen propulsion systems to mitigate contrail-related climate effects will likely depend on further technological optimization as well as additional experimental and in-flight observations to better quantify their atmospheric impacts. This work underscores the importance of linking emission measurements directly to contrail microphysics and provides a framework for evaluating future propulsion technologies based on their actual contrail-forming potential, rather than solely on fuel composition or CO₂ reduction. Full article

Current research in commercial aviation is exploring numerous propulsion and aircraft technologies to mitigate its environmental impact. While purely hydrogen-powered aircraft face manifold challenges, combining hydrogen and conventional fuel may facilitate the introduction of hydrogen-based flight. This study dives into the conceptual design of a parallel-hybrid dual-fuel regional aircraft retrofit based on the D328eco. The assessed retrofit approach aims to extend airframe service life and reduce emissions by incorporating a novel propulsion system. By integrating high-temperature fuel cells (FCs) to assist conventional turboshaft engines, the powertrain reduces fuel consumption. Utilizing the Bauhaus Luftfahrt Aircraft Design Environment, various aircraft-level sensitivities and hybridization strategies were assessed. The fuel/payload ratio was identified as a key metric, and enabling FC support during diversion climb while minimizing that ratio shifted the corresponding hybridization degree from 20.3% to 37.2%. Retaining the reference turboshaft-engine for reduced retrofit development costs, a hybridization degree of 20.2% was attainable while the minimum allowable payload was carried aboard. Subsequent off-design mission analysis revealed a decrease in transport efficiency for reduced mission ranges, underlining the importance of market-tailored aircraft designs. The main studies were complemented by a higher-level emission and climate impact assessment to set the basis for more generalized retrofit statements. Full article

Municipal solid waste (MSW) incineration with energy recovery is embedded in national decarbonization strategies but emits fossil CO₂ from plastic-derived combustion, challenging the long-term sustainability of waste-to-energy systems. Carbon capture and utilization (CCU) offers a potential mitigation route, yet assessments rarely link technology economics, environmental performance, and the carbon-pricing instruments that would finance deployment. This study develops a break-even carbon-pricing framework integrating life-cycle CO₂ emissions (LCCO₂) and discounted annualized life-cycle cost (LCC; capital-recovery-factor annualization at a 4% real discount rate) for two CCU routes—methanation and methanol synthesis—applied to a 300 t/day Japanese incineration facility (84,000 t/y) under 2024 and 2050 energy-system conditions, thereby quantifying the environmental and the economic dimensions of sustainable CCU deployment in the waste sector. Two complementary indicators are distinguished: an incremental break-even carbon price, the price at which adding CCU to the existing waste-to-energy facility becomes economically neutral, and a plant-level cash balance price. Under the product-system boundary and photovoltaic-electrolysis hydrogen, both routes show lower life-cycle emissions than the baseline in both years; the magnitude—and, for methanation in 2024, the sign—of the net climate benefit depends on the downstream-use accounting boundary. The incremental break-even price for methanol falls from 20.3 × 10⁴ JPY/t-CO₂ (≈1293 USD/t-CO₂) in 2024 to 1.90 × 10⁴ JPY/t-CO₂ (≈122 USD/t-CO₂) in 2050, while that for methanation falls from 32.2 × 10⁴ JPY/t-CO₂ to 0.75 × 10⁴ JPY/t-CO₂ (≈48 USD/t-CO₂)—about half the 2023 EU ETS average price—and approaches zero at approximately a one-third capital subsidy. This collapse is driven largely by the assumed hydrogen-price decline (100 → 20 JPY/Nm³); hydrogen-supply policy, rather than carbon pricing alone, therefore appears to be the dominant lever for making CCU at MSW incineration a viable contribution to sustainable, carbon-neutral waste management. Sensitivity analyses covering the discount rate (2–8%), plant scale (300–900 t/day), methane leakage, product-market absorption, and hydrogen delivered price premiums support the robustness of this sequencing conclusion. Full article

Background Aflatoxin B1 (AFB1) is a potent hepatotoxic mycotoxin that induces severe oxidative liver damage. Kaempferol (Kae), a natural flavonoid with known antioxidant properties, has unclear protective effects against AFB1-induced hepatotoxicity. This study aimed to evaluate the hepatoprotective role of Kae and elucidate its underlying mechanism using integrated in vivo, in silico, and in vitro approaches. Methods: In vivo (AFB1-challenged mice) and in vitro (hepatocyte) models were employed, combined with network pharmacology, molecular docking, and molecular dynamics simulations. Liver injury indices, oxidative stress markers, antioxidant enzyme activities, and Keap1/Nrf2 pathway expression were assessed. Results: Kae co-treatment reversed AFB1-induced increases in liver index, serum ALT/AST, histological lesions, and reduced antioxidant capacity in mice. Network pharmacology revealed 59 common targets, with NFE2L2 (Nrf2) as a key node. In vitro, Kae pretreatment significantly lowered AFB1-elevated ROS, MDA, ALT, and AST, while restoring GSH and total antioxidant capacity. Kae reversed AFB1-induced Keap1 upregulation and Nrf2 downregulation, and increased mRNA levels of HO-1, NQO1, SOD, GPX1, and CAT. Molecular docking and simulation showed stable Kae–Keap1 binding (−9.6 kcal/mol) with critical hydrogen bonds (VAL-606) and van der Waals contacts. Conclusions: Kae directly binds Keap1, activates Nrf2 signaling, upregulates antioxidant gene expression, and mitigates AFB1-induced oxidative liver injury. These findings support Kae as a promising candidate for preventing AFB1 hepatotoxicity. Full article

The practical deployment of aqueous zinc-ion batteries (AZIBs) is critically limited by uneven Zn²⁺ flux, uncontrolled dendrite growth, and concurrent parasitic reactions—notably the hydrogen evolution reaction (HER) and anode corrosion—arising from interfacial and kinetic instability during repeated plating/stripping cycles. These issues originate at the zinc anode–electrolyte interface, underscoring the necessity of advanced interfacial engineering. Here, we report a surface-confined polyphenol-derived interphase formed on zinc foil through a 1 min dip treatment in a dilute aqueous solution of a commercial tea polyphenol (TP) mixture (0.02 M); after rinsing and drying, the modified electrode is cycled in a conventional electrolyte to which no TP is deliberately added. This interphase promotes more homogeneous nucleation behaviour through coordination between phenolic oxygen-containing moieties and Zn²⁺, improves electrolyte contact homogeneity and perturbs the local water structure to mitigate water-mediated parasitic reactions. The TP-derived surface modification creates a substantially altered interfacial charging environment (Cdl = 47.25 vs. 16.83 µF cm⁻² for bare Zn) that facilitates more uniform zinc deposition. Symmetric cells with TP@Zn anodes demonstrated exceptional cycling stability exceeding 4000 h at 1 mA cm⁻² and 1 mAh cm⁻² (bare Zn fails within ~240 h under identical conditions), while TP@Zn//V₂O₅ full cells retained 56.2% capacity after 300 cycles at 0.5 A g⁻¹ with a higher median discharge voltage than bare Zn cells, substantially outperforming the latter (31.1% retention). Density functional theory calculations using the selected cluster models yield a markedly more negative electronic interaction energy for Zn²⁺ with an EGCG model ligand (−10.97 eV) than with H₂O (−4.49 eV), qualitatively supporting preferential coordination of Zn²⁺ by phenolic oxygen sites. This work presents a green, facile and potentially scalable interfacial regulation strategy and advances the understanding of natural polyphenols as pre-formed surface conditioners for highly reversible metal anodes. Full article

Lined rock caverns offer a promising option for underground hydrogen, helping to mitigate renewable intermittency and enhance system stability. Considering the geological characteristics of hard rock formations in Southern Ontario, Canada, this study establishes a thermo–gas–mechanical coupled framework that incorporates hydrogen mass and energy evolution in the cavern, gas–wall convective heat exchange, dynamic cavern-volume feedback, and the deformation behaviour of the sealing layer, concrete lining, and surrounding rock. The influences of cavern geometry, sealing material, and in situ stress on the short–term thermodynamic and mechanical responses are further examined. The results show that hydrogen temperature and pressure exhibit clear stage–dependent evolution during the charging–storage–discharging cycle. The comparison between the first and 20th operating cycles indicates that repeated operation mainly causes a moderate adjustment of the cyclic thermal state and temperature–pressure baseline, without changing the overall stage–dependent response pattern. During charging, temperature and pressure increase simultaneously; during storage, both gradually decrease as thermal energy is transferred to the cavern wall; and during discharging, expansion causes pronounced cooling and depressurization, followed by gradual recovery driven by heat transfer from the surrounding rock. Cavern geometry significantly affects stress redistribution around the cavern. The circular cavern shows a relatively uniform stress distribution, whereas the arched cavern is more prone to local stress concentration near the sidewall–floor transition zone. The sealing material mainly influences gas temperature fluctuations through its thermal conductivity. The fibre–reinforced plastic (FRP) sealing layer amplifies thermal fluctuations during cyclic operation, whereas the steel sealing layer promotes heat dissipation through the lining and surrounding rock, thereby moderating cavern–gas temperature variations. In situ stress difference further controls the directional distribution of stresses around the cavern. As the minimum horizontal principal stress increases, compressive stress concentration at the crown and invert becomes stronger, while relative stress release occurs near the sidewalls. These findings provide a thermo–mechanical basis for preliminary cavern–geometry design, comparison of sealing–layer thermal performance, and assessment of in situ stress adaptability for lined rock cavern hydrogen storage in Southern Ontario. Full article

The escalating volume of agricultural waste presents not only a significant environmental challenge but also a substantial opportunity for resource recovery within a circular bioeconomy. This study investigates the feasibility of extracting high-quality cellulose from two underutilized agricultural residues: flower stems and tomato stems. Raw materials were subjected to a multi-stage chemical pulping process involving alkaline treatment, acid treatment, and hydrogen peroxide bleaching in order to remove lignin, hemicellulose, and other impurities. The resulting cellulose samples were comprehensively characterized for their yield, purity (α-cellulose content), degree of polymerization (DP), chemical structure (FT-IR), crystallinity (XRD), and inorganic elemental composition. The results demonstrate that both feedstocks can yield cellulose with an α-cellulose content exceeding 91% and a DP greater than 600, meeting the stringent quality requirements for dissolving-grade pulp intended for such applications as textiles, composite additives and others products. Flower stems showed a higher pulping yield (26.8%) compared to tomato stems (13.7%), highlighting their greater potential. This work validates agricultural residues, particularly flower stems, as a viable and sustainable alternative to traditional wood sources for cellulose production, offering a pathway to mitigate waste and add value to agricultural supply chains. Full article