Search Results (685)

To address the challenges of winter pavement icing and the disposal of organic waste, this study developed a sustained-release deicing filler utilizing biochar derived from spent coffee grounds (SCGs). The material was synthesized through high-temperature carbonization, followed by physical adsorption of chloride salts and surface hydrophobic modification to control release rates. The study made asphalt mixtures and replaced normal mineral filler with the SCG material by volume at ratios of 0%, 50%, 75%, and 100% to test road and deicing performance. Wheel-tracking tests showed that the additive improved high-temperature stability and dynamic stability went up by 27.04% at the 75% replacement level. Salt dissolving created voids and slightly lowered water stability at high dosages, but all performance numbers still met the current engineering rules. Rutting slab tests at −5 °C showed the 100% replacement mix cut snow coverage to 11.43% in 60 min and proved it works for deicing. Pull-out tests measure the bond strength between ice and pavement at −5 °C, −7 °C, and −9 °C. The SCG deicing material weakens ice sticking and the bond strength for the 100% group at −5 °C was 0.35 kN, which is about 57.8% lower than the control asphalt. The bond strength of the deicing mix at −9 °C was still lower than the normal mix at −5 °C. This big drop in stickiness means the pavement stops ice from packing hard and makes mechanical removal easier. This study shows that the prepared deicing materials exhibit excellent sustained-release performance and snow-melting efficiency while ensuring satisfactory road performance. SCG deicing materials can effectively reduce snow accumulation on road surfaces in winter, lower the difficulty of ice-layer removal, and realize the sustainable utilization of SCGs. Full article

Wind and solar power generation represent crucial forms of clean energy utilisation, where generation efficiency is paramount. However, clean energy facilities such as wind turbine blades and photovoltaic sheets frequently cease operation during low temperatures due to ice and frost accumulation, resulting in energy wastage. This study investigates the mechanism of low-temperature surface frost formation through observational experiments. By comparing the temporal progression of frost accumulation on four materials—HIPS (high-impact polystyrene), ABS (Acrylonitrile Butadiene Styrene), acrylic, and acrylic sheet with low-temperature flexible superhydrophobic coating (LFSC)—it validates the anti-frost capabilities of superhydrophobic surfaces. The experimental results show that, under the same conditions, surface frosting gradually decreases as the contact angle of the material increases. After 15 min of frosting, the frost layer thicknesses of the four materials were 0.057 mm, 0.101 mm, 0.105 mm, and 0.275 mm, respectively, and the frost coverage per unit area was 12%, 68%, 76%, and 88%, respectively. The frost formed on the superhydrophobic coating surface was loose and thin, with a frost suppression efficiency exceeding 80%. In contrast, the three materials—HIPS, ABS, and untreated acrylic sheets—exhibited significant frost particle accumulation, and as time progressed, a cycle of frost crystal growth, melting, and regrowth occurred. This study demonstrates that superhydrophobic surfaces possess excellent frost-inhibiting capabilities, which can reduce the energy consumption associated with traditional defrosting methods such as heating and spraying chemical de-icing agents, thereby enabling the sustainable use of energy. Full article

Wind power has experienced rapid development due to its renewable advantages. To address the performance degradation of wind turbines caused by icing in alpine regions, this study integrates field testing and numerical simulation to analyze three key aspects for a 1.5 MW turbine: the underlying mechanism of icing impact, the effect of a de-icing coating on performance during ice-free operation, and the coating’s efficacy under active icing conditions. Results show that ice accretion causes a 25% power loss, induces severe flow separation and vortex shedding, and shifts the separation point forward to 15% chord length. Under ice-free conditions at an average wind speed of 8.3 m/s, the de-icing coating introduces a negligible power deviation of only 0.4%. In extreme cold, ice thickness on the coated blade section was measured at just 4.86 cm. The research demonstrates that de-icing the outer 10 m blade tip section substantially improves performance and confirms that the coating has a minimal aerodynamic footprint during normal operation while providing effective ice mitigation. These findings offer a scientific foundation for optimizing de-icing techniques and support the broader application of such coatings for wind turbines in cold climates. Full article

Icing poses significant operational and safety risks in aviation, especially for engine components such as cowls and baffles. This study explores the potential of a chemically exfoliated graphene-rich carbon platelet epoxy coating to improve the anti-icing and de-icing performance of 3003-H14 aluminum alloy, which is widely used in such applications. Chemically exfoliated graphite was incorporated into an epoxy resin, then applied to aluminum substrates. Characterization of the coated samples revealed ~30% improvement in surface Vickers hardness (HV) (HV 75.6 ± 1.15 vs. HV average of 98.3 ± 1.5) and enhanced thermal dissipation, with coated surfaces cooling from 104 °C to 22 °C in 530 s compared to 870 s for uncoated samples. While anti-icing performance was not directly evaluated, the observed improvements in thermal dissipation and surface hardness suggest that chemically exfoliated graphene-rich carbon platelet coatings could be promising for passive anti-icing applications. The literature suggests that graphene coating improves hydrophobicity, reducing ice adhesion and delaying nucleation due to its low surface energy and nanoscale roughness, thereby supporting potential passive anti-icing functionality for aircraft engine components. SEM analysis confirmed a uniform, compact coating layer. These preliminary findings indicate that chemically exfoliated graphene-rich carbon platelet coatings can deliver multifunctional performance—mechanical, thermal, and surface—making them promising candidates for passive anti-icing/de-icing solutions in engine components where conventional systems are ineffective. Full article

The cloud spatial uniformity in the test section is crucial for icing wind tunnels in aircraft icing research and airworthiness certification. To achieve uniform supercooled large droplet (SLD) icing conditions, both the spatial variation in droplet size distribution and the concentration should be considered. In this study, the spatial distribution of droplets under three SLD conditions is explored in the Aviation Industry Corporation of China Aerodynamics Research Institute (AVICARI)’s FL-61 icing wind tunnel. Measurements are conducted at 12 test points in vertical and horizontal directions using the holographic airborne cloud particle imager (HACPI) in conjunction with a two-axis traversing system. The droplet images obtained at specific test points below the test section centerline show deformation phenomena for droplets larger than 400 $\mathsf{\mu }$m. Additionally, the aspect ratio of deformed droplets increases with droplet size. The spatial evolution of the median volume diameter (MVD) and liquid water content (LWC) is examined. For two spray arrangements where the activated nozzles are positioned close, the test point where the LWC peak in the vertical direction occurs is higher than that of the MVD peak. Further analysis focuses on the size distribution of droplets in the vertical direction. The results show that the settling effect of the droplets larger than 50 $\mathsf{\mu }$m is evident under a flow velocity of 78 m/s. Meanwhile, the position where large droplets tend to appear lowers as the droplet size increases. Finally, the spatial uniformity of droplet size distributions at the same radial distance is discussed. Full article

Snow accumulation and ice formation can significantly reduce pavement friction, posing a serious threat to traffic safety during winter. Traditional snow-removal methods, including mechanical removal, chemical de-icing agents, and heated pavement systems, suffer from several limitations such as low efficiency, environmental impacts, and high operational costs. Electrically conductive asphalt concrete (ECAC) has therefore emerged as a promising active snow-melting technology. When an electric current passes through the conductive network formed within the asphalt mixture, heat is generated through the Joule heating effect. After incorporating conductive fillers, the electrical resistivity of ECAC mixtures can be reduced from approximately 10⁶–10⁸ Ω·cm for conventional asphalt mixtures to about 10⁻¹–10² Ω·cm. Under an applied voltage typically ranging from 30 to 60 V, ECAC pavements can increase the surface temperature by 10–30 °C within 10–30 min, thereby enabling rapid snow melting and ice removal. Meanwhile, an optimized conductive network can maintain sufficient mechanical performance, with dynamic stability generally exceeding 3000 cycles/mm. When the conductive filler content is reasonably controlled, only a limited reduction in fatigue resistance is observed. This paper presents a comprehensive review of electrically conductive asphalt concrete technologies for snow-melting pavements. The background, underlying mechanisms, material development, system configuration, and field applications of ECAC are systematically summarized. Finally, the current challenges are discussed, including the stability of conductive networks, the trade-off between electrical conductivity and pavement performance, and electrical safety. Future research directions focusing on material optimization, intelligent power control, and long-term field performance evaluation are proposed to support the practical application of ECAC pavements in sustainable winter road maintenance. Full article

Devastating or nearly invariably fatal infections caused by free-living amoebae (FLA), including Acanthamoeba keratitis (AK), granulomatous amoebic encephalitis (GAE), and primary amoebic meningoencephalitis (PAM), remain a significant public health concern, driven by increasing case numbers, geographic expansion, and the lack of approved, effective, and safe treatments. Despite decades of research, no new drugs have been successfully approved, highlighting the severe limitations of de novo drug development for these infections, particularly for GAE and PAM, largely due to the challenges of conducting clinical trials for these rare and rapidly lethal diseases. In this context, drug repurposing represents a cost-effective and promising strategy to accelerate therapeutic advances and overcome key bottlenecks of conventional drug development. Accordingly, we conducted a systematic review of in vitro studies and animal models of AK, GAE, and PAM reported in indexed databases to identify promising drug repurposing candidates against FLA infections. After screening 23,624 records, 112 studies were included in the analysis. Overall, 2726 drugs and drug combinations, spanning 865 pharmacological classes and approved for 565 therapeutic indications, were assessed for their repurposing potential. Among these, 166 compounds showed substantial trophocidal activity (≥IC₅₀) at potentially translatable concentrations (≤10 µM), including six with additional cysticidal activity. In vitro, four compounds were active against Balamuthia mandrillaris, 44 against Acanthamoeba spp. (three cysticidal), and 115 against Naegleria spp. (three cysticidal). In in vivo studies, sulfadiazine and rifampicin were effective as preventive or early monotherapies for GAE. For AK, the combination of polyhexamethylene biguanide, neomycin, and atropine, as well as voriconazole and nitazoxanide monotherapies, showed the greatest promise. In PAM, azithromycin alone or in combination with amphotericin B emerged as the most promising therapeutic options. Further studies are required to advance the clinical translatability of these findings. To the best of our knowledge, this work provides the first comprehensive and integrated synthesis of repurposable drug candidates against FLA infections. Full article

This study assessed the structural stability and in vitro antioxidant capacity of a cosmetic formulation incorporating sangre de grado extract (Croton lechleri Muell) and vegetable oils from aguaje (Mauritia flexuosa L.f.), aguaymanto (Physalis peruviana L.), super sacha inchi (Plukenetia huayllabambana sp. nov.), and sacha inchi (Plukenetia volubilis L.), sourced from Peruvian biodiversity. Structural characterization was conducted using Attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) on the formulation at the initial time point (ASC T0) and after six months under accelerated stability conditions (ASC T6). Characteristic absorption bands corresponding to carbonyl, ether, and hydroxyl functional groups were observed, confirming the structural integrity of the lipid–polymeric components within the emulsifying system. Antioxidant activity was evaluated using DPPH and ABTS assays, with IC₅₀ values comparable to those of a commercially available cream. In the DPPH assay, ASC T6 exhibited IC₅₀ of 5744.8571 μg/mL, comparable to a commercial formulation (5641.1585 μg/mL). In the ABTS assay, ASC T0 demonstrated antioxidant activity statistically equivalent (p > 0.05) to that of the commercial cream, with IC₅₀ values of 410.2358 and 420.2202 μg/mL, respectively. In conclusion, the preservation of antioxidant activity is attributed to the structural integrity of the formulated system, which stabilized and retained synergistic interactions of the antioxidants. Future studies should explore the incorporation of additional antioxidants and include in vivo instrumental assessments of stability and efficacy. Full article

Ice accretion along aircraft leading edges, particularly at stagnation line parting strips, remains difficult to remove using conventional electrothermal anti-icing systems. These systems require continuous high-power heating to maintain the stagnation region above the melting point, often exceeding 10–12 kW/m². This study introduces an Ice Cavitation Deicer (ICD) that removes ice through rapid, localized cavitation generated within a thin melt layer formed at the ice–surface interface. In the proposed approach, a short pulse of electric current melts a 1–10 µm interfacial layer and causes a cavitation impulse of approximately 1–10 MPa. This impulse ejects the stagnation-line ice in a direction normal to the surface, often against the external airflow, enabling the immediate aerodynamic removal of the remaining ice. Analytical modeling based on the energy conservation principle was used to determine the optimal foil geometry, thermal pulse parameters, thermal stress, and material selection. Experiments with various metallic foils and substrate materials validated the predicted ejection behavior. The impulses were sufficient to fracture and eject ice 1–10 mm thick. The observed ice fragment velocities varied from 1 m/s to 10 m/s. Compared with conventional thermal anti-icing, the ICD concept reduces power consumption by approximately two orders of magnitude while offering rapid and reliable leading-edge deicing. The low power requirements, rapid response, and compatibility with thin-foil heater architectures make ICD a promising technology for both conventional and electrified aircrafts, UAVs, rotorcrafts, and other platforms where power availability is limited. This manuscript presents the first theoretical and experimental research on the ICD method and is a concept-proof work. Further research and development are required before the ICD is ready to be tested in flight. Full article

Demand for cosmetics based on green production and the circular economy is growing. The inflorescences and apical leaves of Nicotiana tabacum (tobacco) after blunting, deflowering, or topping are considered pre-harvest waste biomass. Using green and ecofriendly solvents such as natural deep eutectic solvents (NaDESs) offers a sustainable way to make use of this biomass for incorporation in cosmetic formulations. The inflorescence and apical leaves of tobacco var Virginia were therefore dried, powdered, and extracted using a NaDES composed of choline-chloride, urea, and distilled water (NaDES CU). The resulting inflorescence and apical leaves extracts showed high concentrations of phenolic compounds and flavonoids. Both extracts demonstrated significant biological activity and effectively inhibited tyrosinase, the enzyme responsible for melanin regulation and skin aging (IC₅₀ = 50 μg GAE/mL), as well as showing antioxidant capacity (ABTS^•+; SC₅₀ =1.7–7 μg GAE/mL). Ten nanoemulsions containing tobacco leaf- and inflorescence extract-based NaDES CU, formulated using different polysorbates, deionized water and glycerin, were produced. A low-energy emulsification technique at a constant temperature was applied. Considering the droplet size and polydispersity index, only the nanoemulsions containing inflorescence and leaf extracts based on NaDES CU and containing 5% or 10% polysorbate 85 were selected for further stability assessment and characterization. This study highlights the potential of NaDES combined with tobacco waste extracts as a sustainable and non-toxic ingredient in anti-aging and antioxidant cosmetics. Full article

Deep-sea mollusks represent untapped resources for searching novel biologically active peptides effectual against many chronic diseases. Here we presented the identification of four novel angiotensin I-converting enzyme (ACE) inhibitory peptides from the deep-sea mollusk Gigantidas platifrons by using a combined approach of peptidomics and virtual screening. Fifteen protein hydrolysates from five deep-sea macroorganisms were prepared using three different proteases and were determined for their ACE inhibitory activities. Pepsin hydrolysate of G. platifrons protein (GPp) demonstrated the highest inhibition rate against ACE at 400 μg/mL. Then, targeted investigation was conducted on the GPp with peptidomic profiling; more than 3000 peptides were de novo identified, which were then subject to virtual screening using the docking software Smina. Subsequently, 29 peptides were selected and synthesized based on the affinity threshold and the interactions with ACE active sites. More than 58% peptides were biologically active, showing more than 50% inhibition to ACE at 400 μM. Four peptides, LAAHFAR, YAAPYR, NGAGPYGRP, and FTTFGK, exhibited low micromolar inhibition. The most potent peptide, LAAHFAR with an IC₅₀ of 6.01 ± 1.06 μM, was subject to molecular dynamics simulations for revealing atomistic interaction analysis. LAAHFAR forms comprehensively stable hydrogen bonds with the classic active site of ACE, and its N terminal arginine residue is anchored by additional hydrogen bonding to Cys370, Asp377, and Thr372. This study highlights deep-sea mollusks as an important source of novel ACE inhibitory peptides, contributing to the development of new therapeutic ingredients or functional food agents against hypertension. Full article

Energy obtained by green ways with releasing environmental pollution is still a challenge for sustainable development for model society. Among energy technologies, photothermal conversion by using solar energy has become a new field and a hot topic in recent years. Based on the exploration of nanomaterials in the past decades, photothermal nanomaterials by using nanomaterials bring new chances for expending the utilization of green energy with high efficiency, mainly including metal semiconductors and carbon nanomaterials. Their modulated structure for enhancing light absorption, accelerating transformation of photon into heat, and located heat management were also considered important for promoting the utilization of solar energy and therefore, the strategies for designed and controllable preparing of photothermal nanomaterials were also summarized. The applications of photothermal nanomaterials were also reviewed to reveal the new chances for energy conversion engineering or promoting the solar energy utilization of solar energy in some cold regions or somewhere with low solar irradiation. Full article

The widespread application of road deicing salts in northern regions has led to elevated salinity in roadside soils and adjacent watersheds. Phytoremediation offers a cost-effective and sustainable approach for mitigating salt contamination, but its success depends on utilizing plant species that can both tolerate and remove salt under roadside conditions. To systematically identify high-potential candidates from the large inventory of salt-tolerant plants in North America, we developed a quantitative decision matrix incorporating criteria related to ecological safety, establishment potential on disturbed soils, aboveground biomass production, biomass use-value, and salt uptake capacity. Thirteen of the highest-ranked species were subsequently evaluated for sodium (Na⁺) and chloride (Cl⁻) uptake in a controlled greenhouse study under saline and non-saline conditions. The greatest total salt uptake was observed in common sunflower (Helianthus annuus) (35.6 mg Na⁺ and 100.2 mg Cl⁻ plant⁻¹) and pitseed goosefoot (Chenopodium berlandieri) (18.6 mg Na⁺ and 76.0 mg Cl⁻ plant⁻¹), while perennial species including tall fescue turfgrass (Lolium arundinaceum), showy goldenrod (Solidago speciosa), and weeping alkaligrass (Puccinellia distans) also demonstrated substantial uptake combined with greater long-term suitability for roadside management. Overall, this study presents a quantitative framework for phytoremediation species selection and provides experimental evidence supporting both annual and perennial species for mitigating deicing salt contamination through environmentally sustainable, low-input roadside management strategies. Full article

Cyclic freezing and thawing (FT) are a primary cause of cracking in concrete, yet current assessment procedures in Germany rely heavily on qualitative estimation using the International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM) capillary suction, internal damage and freeze-thaw (CIF) and Capillary de-icing freeze-thaw (CDF) tests. Although these standard tests provide a general overview of the condition of concrete damage in specimens through the estimation of water saturation through capillary suction, mass of surface delamination, qualitative open surface damage, and relative dynamic modulus of elasticity, they do not take quantitative analysis of voids, including cracks and air pores, directly into account. To address this, we propose a novel workflow utilizing deep learning-based semantic segmentation with Fourier-based slice-to-volume registration by combining 2D light microscopy (LM) of petrographic sections and 3D micro-computed tomography ($\mu$CT). We segment cracks, air pores, and aggregates in both modalities and employ feature matching alongside spatial harmonics analysis for 3D shape description. The best proposed 3D registration framework through feature matching demonstrated a success rate of 89.75%, achieving a dissimilarity of 5.21% in relative root mean square error (RRMSE) terms and thereby significantly surpassing the performance of compared 2D-only methods adapted from the body of research. Our approach enables precise, automated, and verifiable quantification of voids across CT and LM modalities and paves the way for advanced computational modeling-based methods to investigate moisture transfer mechanisms for more accurate assessments of frost damage in concrete, service life prediction models, deep learning applications for multimodal data fusion, and more comprehensive FT damage simulations. Full article

Large-scale mining of graphite, a crucial strategic mineral, generates substantial amounts of graphite tailings (GT). The stockpiling of this solid waste occupies vast land resources and poses persistent environmental risks due to potential heavy metal leaching. Repurposing GT into construction materials presents a promising solution, with its use as a partial replacement for fine aggregates in cementitious composites being one of the most effective methods. This review systematically consolidates current research on graphite tailings cement mortar (GTCM) and graphite tailings concrete (GTC). Due to its physicochemical properties comparable to natural sand, GT is suitable for producing building materials. Studies consistently demonstrate that a substitution level of 10% to 20% optimizes overall performance. This optimal range enhances particle packing, promotes cement hydration via pozzolanic activity, and refines the microstructure, leading to improved workability, superior mechanical strength, and enhanced durability, including resistance to permeability, freeze–thaw cycles, and chemical attacks. Moreover, the inherent carbon content imparts electrical conductivity to GTC, enabling functional applications like de-icing and structural health monitoring. The successful utilization of GT also extends to lightweight foamed and autoclaved aerated concrete. However, research on the structural behavior of GTC components remains limited. Preliminary findings on beams and columns are encouraging, but comprehensive studies on their seismic performance and design methodologies are urgently needed to facilitate the widespread engineering application of this sustainable material and mitigate the environmental impact of tailings accumulation. Full article