Search Results (399)

In this study, 8YSZ thermal barrier coatings (TBCs) were deposited on IC21 single-crystal superalloy substrates. Short-term overheating at 1300 °C was conducted for durations of 1, 5, and 10 min under both uniform temperature and simulated service conditions, followed by thermal cycling and thermal shock tests, respectively, to investigate the short-term overheating behavior of the coatings. The effects of short-term overheating on microstructural evolution and stress evolution under different conditions were analyzed, and the underlying damage mechanisms were determined. The results show that under uniform temperature conditions, short-term overheating drives the continuous growth of the thermally grown oxide (TGO). Coating failure occurs at the specimen edge, dominated by thermal stress concentration induced by geometric edge effects. The stress evolution is relatively mild, and the damage mechanism is primarily long-term interfacial degradation. Under simulated service conditions, short-term overheating induces sintering and cracking in the ceramic top coat. Coating failure occurs at the specimen center, dominated by crack coalescence. Transient temperature gradients generate high non-steady-state thermal stresses. The damage mechanism involves thermomechanical loading accelerating interfacial degradation, with synergistic effects of ceramic layer sintering and TGO destabilization, leading to a significant reduction in coating lifetime. Full article

Gout is a metabolic disorder associated with abnormal purine metabolism and persistent hyperuricaemia, which promotes formation and deposition of monosodium urate crystal in joints, leading to acute arthritis and impaired quality of life. This study aimed to evaluate the xanthine oxidase inhibitory activity of ethanolic leaf extract of Abies kawakamii and its fractions. The protocol of bioassay-guided fractionation was employed to isolate active compounds from leaf extract. Maltol was identified as the major active compound from the ethyl acetate fraction (EAF). Maltol inhibited xanthine oxidase with IC₅₀ values of 33.18 and 26.67 μg/mL against xanthine and hypoxanthine, respectively, significantly lower than the crude extract (152.04 and 136.57 μg/mL) and EAF (66.70 and 48.76 μg/mL). Enzyme kinetic analyses further showed that EAF inhibited xanthine oxidase through a competitive inhibition mechanism toward both substrates. Molecular docking analysis suggested that maltol may interact with the active-site region of xanthine oxidase, showing a binding affinity of −6.5 kcal/mol, slightly weaker than that of allopurinol, with no predicted hepatotoxicity based on in silico analysis. Our findings indicate that A. kawakamii leaf extract and its constituent, maltol, could be further explored as a natural approach for gout management. Full article

Staged upward seepage can trigger particle migration and pore-structure adjustment in graded sandy soils, but the resulting transition behavior remains difficult to identify quantitatively. In this study, three representative sandy soils from a deep overburden deposit in southeastern Tibet were tested using a laboratory vertical upward seepage apparatus. Eight specimens with different nominal preparation states were subjected to stepwise increases in hydraulic head difference. Local hydraulic gradient, seepage velocity, hydraulic conductivity, and macroscopic outflow phenomena were monitored. Apparent seepage-transition hydraulic gradients were identified by combining abrupt changes in k–i curves, conductivity ratios between eligible staged records, and observed seepage responses. The clearest transition occurred in the nominal loose specimen of Soil 2, where the temperature-corrected hydraulic conductivity k₂₀ increased from 1.76 × 10⁻³ to 2.25 × 10⁻² cm s⁻¹ as i increased from 0.20 to 0.25, giving k_20,2/k_20,1 = 12.80 and i_c = 0.225. A clear transition was also identified for the nominal dense specimen of Soil 3, with k_20,2/k_20,1 = 6.61 and i_c = 0.583. Clear transitions were identified in the tested specimens only for Groups D and H, whereas the remaining specimens showed weak or phenomenon-assisted responses, local high-gradient fluctuations, or anomalous loading-path records rather than uniformly identifiable transition points. These results show that apparent transition gradients are path-dependent and should be evaluated together with loading history, seepage-velocity evolution, conductivity ratios, and macroscopic observations. Full article

High-resolution marine sedimentary archives from active continental margins provide exceptional records of paleo-earthquake histories through the preservation of seismogenic turbidites. A 477cm long gravity core (HOBAB4-S2) retrieved from the southern Okinawa Trough (SOT) off eastern Taiwan at a water depth of 1505 m preserves a ~700-year record (1445–2003 AD) of alternating hemipelagic background sedimentation and rapid event deposits. Chronological control is established through accelerator mass spectrometry (AMS ¹⁴C) radiocarbon dating and excess ²¹⁰Pb profiling. Detailed sedimentological and geochemical analyses identify fifteen turbidite events (T1–T15), which are grouped into three lithofacies: TI (silt turbidites), TII (sandy silt turbidites), and TIII (silty sand turbidites). Temporal correlation demonstrates that the majority of these turbidite beds coincide with documented historical and instrumental earthquakes (M_w ≥ 6.6), confirming seismic shaking as the primary triggering mechanism. Notably, turbidite thickness, basal grain size and recurrence frequency increase during the Little Ice Age (LIA, ~1400–1850 AD), a pattern we attribute to enhanced terrestrial sediment supply driven by intensified typhoon activity, which preconditioned the slope system for seismically induced failure. These findings demonstrate that turbidite sequences in the SOT provide a reliable record of local paleo-earthquake activity, while establishing that their stratigraphic expression is modulated by climatically driven sedimentary preconditioning. This principle is critical to paleoseismic reconstruction in seismically active, storm-prone continental margins globally. Full article

Rheumatoid arthritis (RA) management via conventional monotherapy is often limited by poor transdermal flux and suboptimal articular accumulation. This study seeks to bridge a critical gap in monotherapy by engineering chitosan-coated nanobilosomal gel co-encapsulated with thymol and silibinin (CH-TH+SB-BG) in a 3:1 stoichiometric ratio. Compared with monotherapeutics, the CH-TH+SB-BG showed the highest drug content and a sustained drug release profile, accompanied by higher skin permeation and deposition, indicating the fluidizing effect of thymol and the dermal reservoir of silibinin. Interestingly, CH-TH+SB-BG was cytocompatible, owing to its higher IC50 than that of the pure drugs. A marked reduction in the paw volume and arthritic score and significant normalization of hematological, biochemical, and inflammatory biomarkers, compared with the monotherapeutics, indicate the synergistic anti-inflammatory potential of the developed gel. Furthermore, the dual loading effectively reduced oxidative stress, confirmed by a significant decrease in malondialdehyde level along with the restoration of glutathione and superoxide dismutase levels. The Bliss independence model mathematically validated pharmacological synergy. Radiographic and histopathological analysis confirmed the near-complete articular restoration and marked reduction in pannus formation. In conclusion, the developed transdermal gel can be a more effective and safer alternative to long-term oral administration, opening the way for novel topical management of RA. Full article

Ice-dammed lakes were common along the southern margin of the Laurentide Ice Sheet during deglaciation. In the Schoharie Valley of the northern Catskill Mountains, New York, a 171 km² lake known as glacial Lake Grand Gorge formed in an interlobate area. Previous researchers suggested that deltas developed into this glacial lake from meltwater supplied by the adjacent Hudson Lobe during deglaciation. This study investigates stratigraphy and sedimentology of Pleistocene deltas and lake deposits to determine the source of meltwater and sediment. Detailed examination of stratigraphy from quarries, stream exposures, and new exploration borings was combined with radiocarbon and OSL geochronology to establish event stratigraphy. Sedimentologic and geomorphic data from deltas in the Manor Kill and Platter Kill Valleys demonstrates that braided outwash was supplied directly from the Westerlo Sublobe that crossed the northeastern escarpment of the Catskill Mountains. New geochronologic data indicates that the lake was established by 28 ka and likely persisted to at least 22 ka. Insects and twigs recovered from lake sediments complement the OSL data and indicate: (1) that the lake was present significantly earlier than previous deglacial models predict, and (2) that it existed in an ice-free area of the northern Catskill Mountains during the last glacial maximum of the MIS 2 glaciation. Full article

Upcycling biomass waste into value-added battery materials is crucial for sustainable energy storage. Here, we transform coffee grounds into high-performance hard carbon (HC) anodes for sodium-ion batteries (SIBs) via a synergistic pre-oxidation and acetylene chemical vapor deposition (CVD) strategy, which effectively reduces open pores and promotes structural stabilization. The resulting material exhibits features consistent with a closed-pore architecture. Pre-oxidation incorporates oxygen-containing functional groups that template accessible pores and expand the interlayer spacing during carbonization. Subsequent CVD covers surface pores and contributes to the stabilization of the pore structure. The optimized HC (COF300&1300@C) exhibits a balanced set of structural features, including a low specific surface area (2.1 m² g⁻¹), expanded interlayer distance (0.391 nm), and a well-regulated pore system with reduced surface area and controlled pore size. As a result, it delivers a reversible capacity of 298 mAh g⁻¹ with an ICE of 70%, and remarkable cycling stability (97% capacity retention after 500 cycles at 1C). This study elucidates the synergistic mechanism of pre-oxidation and CVD in reducing open pores and stabilizing the pore architecture, thereby yielding characteristics indicative of closed-pore behavior, and providing a novel and efficient approach for designing high-performance biomass-derived hard carbons for energy storage. Full article

A multi-analytical investigation was carried out to elucidate the deterioration processes affecting the stone materials of the Arca di Cansignorio della Scala in Verona (Italy) and to characterize the surviving traces of its original polychrome and gilded decoration. The study combined macroscopic mapping, stratigraphic sampling, optical microscopy (OM), environmental scanning electron microscopy coupled with energy-dispersive X ray spectroscopy (ESEM-EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and ion chromatography (IC). The monument, predominantly carved from Candoglia marble, exhibits three principal weathering patterns: (i) rain washed areas affected by marble decohesion, (ii) grey deposits corresponding to dirt accumulation areas; and (iii) sulphation-induced black crusts developed in dirt wetting areas. In addition, severe mechanical deterioration was found to be associated with early twentieth-century structural consolidation interventions involving embedded iron bars, whose corrosion-driven volumetric expansion generated vertical cracking. Stratigraphic and microanalytical investigations revealed the presence of original azurite-based polychromy, proteinaceous and lipidic binding media, lead white preparatory layers, and multiple applications of gold leaf. The analytical results highlight the complex interplay between environmental exposure, atmospheric pollution, the incompatibility of materials introduced during past restorations campaigns. Furthermore, they contribute to a better understanding of the composition, execution techniques and preservation state of the surviving decorative layers, providing a scientific basis for future conservation strategies. Full article

SiO_x anodes are highly promising for next-generation lithium-ion batteries due to their superior theoretical capacity. However, issues such as drastic volume expansion and low initial Coulombic efficiency (ICE) impede their practical use. While macroporous architectures can mitigate these challenges, traditional fabrication often depends on tedious hard templating methods and significant organic solvent consumption. In this work, we report a sustainable, emulsion-self-templated and organic solvent-free strategy to synthesize a carbon-coated 3D macroporous SiO_x/C composite (3DM-SiO_x/C@C). Our approach uniquely integrates radical polymerization with a water-in-oil emulsion and sol–gel process, followed by chemical vapor deposition (CVD). The 3D macroporous framework is generated via in-situ emulsion droplets acting as self-templates, effectively eliminating the need for external sacrificial templates and toxic etchants. Notably, this organic solvent-free process achieves an exceptional precursor to (precursor + organic solvent) mass ratio of 1.0, contrasting sharply with conventional methods (0.0044–0.17). The resulting hierarchical structure, characterized by interconnected macropores and a uniform carbon coating, significantly enhances structural integrity and electronic conductivity. Electrochemical evaluations reveal that 3DM-SiO_x/C@C exhibits an improved ICE of 74.32% and long-term cycling stability even at a high current density of 1.0 A g⁻¹ compared to non-porous and uncoated counterparts. This integrated synthesis offers a green and scalable pathway for developing high-performance silicon-based anodes for large-scale energy storage. Full article

Shallow lunar subsurface characterization is a key requirement for future exploration activities, particularly for in situ resource utilization and the identification of protected environments for human and robotic operations. This work presents the preliminary design and performance assessment of an orbital very high frequency (VHF) radar sounder tailored to the detection of subsurface water ice deposits and lava tubes at depths relevant to exploration. The analysis combines physically based modeling of acquisition geometry, electromagnetic properties, and surface roughness with quantitative evaluation of signal-to-noise and signal-to-clutter ratios. Results indicate that surface clutter constitutes the primary limitation for subsurface detectability in orbital sounding, thereby driving both instrument design and mission geometry. Quantitative performance bounds are derived for penetration depth and spatial resolution, providing guidance for identifying regions where subsurface access may be achieved with reduced operational risk. One-dimensional electromagnetic simulations further demonstrate the advantages of operating in the VHF regime. While lower-frequency systems retain sensitivity to some subsurface interfaces, their limited vertical resolution prevents reliable separation of closely spaced structures, such as the roof and floor of lava tubes. In contrast, the proposed VHF sounder enables clear separation of multiple subsurface interfaces, allowing geometric characterization of cavities and improved discrimination of ice-bearing layers. These results establish the feasibility and relevance of a VHF orbital radar sounder as a dedicated tool for shallow lunar subsurface investigations in support of future exploration missions. Full article

The search for extraterrestrial life has traditionally focused on environments where liquid H₂O is stable over long timescales, such as subsurface aquifers, hydrothermal systems, or ice-rich deposits. However, many planetary bodies are characterized by active cycles of particulate transport involving either mineral dust or atmospheric aerosols. In planetary science, these are commonly distinguished as refractory particles (non-volatile mineral dust) and volatile or mixed aerosol particles, including condensates such as ices, organics, or acidic droplets. Here, we propose the concept of planetary aerobiomes, defined as distributed particle-associated microbial persistence and dispersal systems in extraterrestrial environments. In this framework, refractory mineral particles may act as mobile particle-associated microenvironments that could support microbial survival and dispersal, while in some cases also providing partial physical shielding from environmental stressors. Drawing on observations from terrestrial dust-associated microbiomes and mineral–microbe interactions, particle-associated systems may represent previously overlooked ecological substrates in planetary environments. Rather than replacing models centred on environments with persistent liquid H₂O, this perspective expands them by considering particle-associated microenvironments as transient but potentially relevant biosignature-preservation niches in arid, dust-dominated worlds such as Mars, as well as in aerosol-rich environments including Titan, Venus, and icy moons. We further discuss the implications for life-detection strategies, highlighting atmospheric particles as potential reservoirs of biosignatures, and consider their relevance for applied microbiology, including in situ resource utilization (ISRU) and bioregenerative life-support systems (BLSS). Beyond astrobiological implications, understanding microbial persistence within particle-associated extreme environments may provide useful models for applied microbiology, including stress-resilient microbial engineering, biomining, contamination control, and bioregenerative technologies for space exploration. Full article

Cymodocea nodosa, growing at low water depth, is affected by various environmental changes and is expected to adapt to oxidative stress. Oxidative stress in living leaves (LC) and beach deposits (NC) of C. nodosa activated superoxide dismutase (SOD), which was higher in LC, leading to significant neutralization of the produced H₂O₂ and destruction of protein generation. Higher antioxidant capacity (using a UV/Vis spectrophotometer) to scavenge 2.2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS^•+) (IC₅₀: 5 in LC vs. 22 μg mL⁻¹ in NC) and OH^• (hydroxyl) radicals (IC₅₀: 132 in LC vs. 281.7 μg mL⁻¹ in NC), compared to 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) (IC₅₀: 63 in LC vs. 45 μg mL⁻¹ in NC) and superoxide anion (O₂^•−) radicals (IC₅₀: 190 in LC vs. 94 μg mL⁻¹ in NC), and similar reducing power (RP) were recorded in LC compared with NC extracts (IC₅₀: 53 in LC vs. 52 μg ml⁻¹ in NC). Phenolic compounds were not significantly lost during plant exposure on shores (mean value: 57.00 in LC vs. 45.48 mg g⁻¹ d.w. in NC). Phenolic compounds identified, using UHPLC-DAD analysis, in both LC and NC extracts were chicoric, trans-ferulic, caftaric, p-coumaric, sinapic, and trans-cinnamic acid and rutin hydrate, whereas caffeic acid, in traces, was identified in NC extracts. NC showed higher cytotoxic activity in inhibiting LS 174 colon cancer cells than LC. In cases of plant cultivation or management plans for seagrass meadows and their beach deposits, with the least possible impacts, both LC and NC extracts could be exploited for their antioxidant and anticancer properties. In a ‘case study’, the amounts of individual phenolic compounds that can be produced from NC utilization were estimated. Full article

Aqueous zinc-ion batteries are promising for large-scale energy storage due to their intrinsic safety, low cost, and environmental friendliness. However, their practical application is severely impeded by water-induced parasitic reactions and uncontrollable dendrite growth at the anode interface. Furthermore, the freezing of aqueous electrolytes at subzero temperature restricts their all-weather viability. Herein, we report a hydrogel electrolyte with interfacial regulation capabilities. By optimizing interfacial ion transport, the hydrogel electrolyte guides uniform Zn²⁺ deposition, effectively mitigating parasitic reactions and dendrite growth while enabling exceptional low-temperature tolerance. Consequently, the symmetric Zn//Zn cell using the hydrogel electrolyte delivers ultra-high cycling stability for 4000 h at 0.5 mA cm⁻² under −30 °C. When assembled into full cells, the Zn//NH₄V₄O₁₀ configuration operates stably for 4000 cycles at 5 A g⁻¹, exhibiting outstanding capacity retention. Furthermore, the assembled flexible pouch cell maintains 86% of initial capacity after 900 cycles at 3 A g⁻¹. Notably, the pouch cells demonstrate reliable operation and structural integrity under severe conditions, such as ice baths, bending, and piercing. This work provides an effective strategy for durable, wide-temperature, and intrinsically safe flexible aqueous energy storage systems. Full article

In the northeastern United States, sediments related to the expansion and contraction of the Laurentide ice sheet have been extensively mapped throughout New England, as well as in New Jersey and on Long Island. However, linking these deposits around New York City is challenging due to the extensive urbanization. Staten Island is less developed than the other boroughs of New York City, however outcrops of rock and surface sediment are limited, making interpretation of its geologic history challenging. When small areas of sediment are temporarily exposed, they can be used to improve our understanding of sediment erosion and deposition over time, helping to link the deposits mapped in New Jersey and Long Island. In this study of two small temporary outcrops, the beds of sediment were measured and described in the field and samples were collected for textural and compositional analyses. The results were interpreted in the context of previous work on similar exposures nearby. The sediments are sands and gravels of fluvioglacial origin containing reworked sediments of both the Pliocene Pensauken Formation and older Triassic rocks of the Newark Basin, interpreted to have been deposited on an outwash plain during the Illinoian glaciation (Marine Isotope Stage 6). They were deposited in a topographic low directly overlying Cretaceous sedimentary rocks, but adjacent to sediments of the Pensauken Formation which had in turn been deposited as an earlier valley fill. Similar sequences of repeated valley fills have been observed in New Jersey but have not been documented on Staten Island. This interpretation solves an apparent disagreement between previous studies by illustrating how both the Pensauken Formation and later fluvioglacial sediments can directly overly Cretaceous sediments across a distance of less than a kilometer. Full article

Chromium-forming metallic interconnectors (ICs) are generally used to assemble protonic ceramic fuel cell stacks (PCFCs). Thus, Cr poisoning is a potential threat to the performance and stability of PCFCs. The effects of Cr deposit and poisoning on the performance and stability of a typical BaCo_0.8(Zr_0.8Y_0.2)_0.2O_3-δ (BCZY) air electrode after polarization with a current density of 0.2 A cm⁻² for 50 h are investigated. It is found that the BCZY and Cr₂O₃ powder are able to react even at 400 °C. In addition, Cr poisoning affects the chemical stability of BCZY. The humidification of air accelerates the Cr deposition and poisoning of BCZY by promoting the surface segregation of Ba and Cr evaporation from IC, and the main phase of the surface deposit is BaCrO₄. When the air humidity increases from 3% to 50%, the deposit layer depth increases from 0.949 μm to 2.870 μm. For the fuel cell exposed to air with a relative humidity of 3% and 50%, the polarization resistance (R_p) increases by 19.9% and 53.3%, while the ohmic resistance (R_Ω) increases by 3.5% and 17.1%, respectively. This study lays the foundation for further design of Cr-tolerant air electrodes and the selection of working conditions. Full article