Search Results (24,657)

The aim of this study was to investigate the chemical composition and biological activity of extracts obtained from vegetative cranberry biomass generated during plantation rejuvenation. This biomass, composed mainly of young shoots removed during routine agricultural maintenance, represents a readily available and currently underutilized by-product of commercial cranberry (Vaccinium macrocarpon Aiton) cultivation. Extraction optimization was performed using response surface methodology (RSM), which enabled both the assessment of the effects of process variables and the identification of conditions ensuring maximal extraction efficiency. The optimal parameters were determined to be 40% ethanol, a temperature of 60 °C, and an extraction time of 49.44 min, and these conditions were further validated through an additional triplicate extraction. The resulting extract exhibited a high antioxidant activity (429–490 mg Trolox equivalents per gram) and was rich in phenolic compounds, particularly quercetin glycoside derivatives. The chemical profile and bioactivity of the extract highlight the considerable potential of cranberry pruning biomass as an alternative, sustainable source of high-value phytochemicals. Its valorization may support the development of environmentally friendly extraction technologies and contribute to closing the resource loop within agricultural production systems. Full article

Human skin lipids form interconnected pools that support barrier integrity, immune balance, and interactions with the environment. The stratum corneum barrier is built from an ordered mix of ceramides, cholesterol, and long-chain free fatty acids, while sebaceous lipids and their breakdown products shape surface properties and the skin microbiome. Hexadecenoic fatty acids are key at this interface. Palmitoleic acid (cis-9 16:1; 16:1 n−7, POA) is enriched in viable epidermis and remains detectable in stratum corneum lipids, whereas its isomer sapienic acid (cis-6 16:1; 16:1 n−10) predominates in human sebum. Together, they influence membrane organization, lipid fluidity, and antimicrobial defense. This mini-review outlines skin lipid composition and function with a focus on POA and then summarizes experimental and preclinical topical evidence suggesting antimicrobial effects, enhanced lubrication properties, protection from oxidative and ultraviolet B (UVB) injury, and enhanced wound repair. It also reviews early clinical findings from oral POA supplementation trials reporting improved hydration, barrier function, and markers of photo-oxidative aging, with exploratory signals for acne in a multi-nutrient regimen. Major POA sources include sea buckthorn pulp oil, macadamia and avocado oils, selected marine oils, ruminant fats, and emerging fermentation-derived products. Robust mechanistic human studies are still needed to define optimal dosing, formulations, and indications. Full article

In-space manufacturing is essential for achieving long-term planetary colonization, particularly on Mars, where material transport from Earth is both costly and logistically restrictive. Traditional subtractive manufacturing methods are highly equipment-, energy-, and material-intensive, making additive manufacturing (AM) a more practical and sustainable alternative for extraterrestrial production. Among various AM technologies, laser beam powder bed fusion (PBF-LB) stands out due to its exceptional versatility, precision, and capability to produce dense metallic parts with complex geometries. However, conventional PBF-LB processes rely heavily on inert argon environments to prevent oxidation and ensure high-quality part formation—conditions that are difficult to reproduce on Mars. CO₂ makes up over 95% of the Martian atmosphere, meaning printing in a majority-CO₂ environment is of great interest for in situ manufacturing in a Martian colonization effort. This study investigates the feasibility of using pure carbon dioxide (CO₂) as a potential substitute for argon in PBF-LB manufacturing. Single-track and two-dimensional 316L stainless steel specimens were fabricated under argon, CO₂, and ambient air environments with a wide range of laser parameters to evaluate the influence of atmospheric composition on surface morphology, microstructural cohesion, and oxidation behavior. The results reveal that no single parameter controls the overall part quality; rather, a balance of parameters is essential to maintain thermal equilibrium during fabrication. Although parts produced in CO₂ exhibited slightly inferior surface finish, cohesion, and oxidation resistance compared to argon, they performed significantly better than those fabricated in ambient air in terms of balling effects and overall cohesion. These findings suggest that CO₂-assisted PBF-LB could enable sustainable in situ manufacturing on Mars and may also serve as a cost-effective alternative shielding gas for terrestrial applications. Full article

“Rotten” sea ice, ice in an advanced stage of melt, represents an important but understudied habitat in the rapidly changing Arctic. As Arctic warming accelerates, this late-season ice type will become more prevalent, yet little is known about its microbial inhabitants or their roles in Arctic marine biogeochemical cycles. We examined microbial communities (prokaryote and algal abundance, 16S and 18S rRNA gene and transcript sequencing) and biogeochemical properties of rotten sea ice and earlier-season ice near Utqiaġvik, Alaska, USA. Rotten ice was comparatively warm, isothermal, and largely drained of brine, with extensive, interconnected pore networks linked to melt ponds above and seawater below. Unlike earlier-season ice, fluids saturating rotten ice were vertically homogeneous in pH, dissolved inorganic carbon, prokaryote and phytoplankton abundance, and microbial community composition. However, particulate carbon and nitrogen exhibited strong vertical gradients, with the highest concentrations near the surface. Microbial communities in rotten ice were significantly different from those in earlier-season ice and varied between individual floes. These findings indicate that rotten ice constitutes a distinct microbial habitat and may serve as an important source of nutrient-rich particulate matter in the future Arctic Ocean during the summer melt season. Full article

From Palaeolithic ornaments to modern biomimetics, the use of nacre and shells has evolved. Initially utilised for jewellery and tools, they now inspire the development of advanced materials. This paper reviews the current knowledge on nacre’s composition, focusing on the highly regulated biomineralisation process wherein amorphous calcium carbonate (ACC) transforms into crystalline aragonite. It examines the important role of the organic matrix (specifically soluble, insoluble, and acidic proteins) in controlling crystal nucleation, growth, and polymorph selection. Scientists study natural nacre formation to create nacre-inspired composites for various applications. Charles Hatchett’s in 1799 shell categorisation, Sorby and Sowerby’s 19th-century microscopy, Taylor, Beedham, Bøggild, and Currey’s mid-20th-century research on bivalve structures, and mechanical property investigations in the 1970s are some of the major developments. The hierarchical structure, cooperative plastic deformation, surface asperities, organic–inorganic interactions, and interphase in such complex composite materials give rise to impressive mechanical properties. In the early 2000s, with the emergence of biomimetics, inspired by nacre, several macroscopic structural materials with uniform micro- and nanoscale architectures have been synthesised in recent decades, and their mechanical properties and potential applications have been explored. Modern nacre-inspired fabrication utilises 3D printing for precision, freeze casting for sustainability, and mineralisation for scalability. Techniques like layer-by-layer assembly and nanomaterial integration enhance mechanical performance through advanced interfacial engineering. Full article

This study investigates the synergistic and fineness-dependent modification of base asphalt using rice husk biochar (RHB) and styrene–butadiene–styrene (SBS), aiming to achieve the efficient utilization of agro-waste resources while markedly improving the high-temperature performance and durability of green pavement materials and sustainable transportation infrastructure. Through conventional performance tests, rheological measurements, and microstructural analyses, the performance behavior of RHB-SBS composite-modified asphalt and the interaction mechanisms between the modifiers were systematically examined. The results indicate that the fineness of RHB has a significant effect on the performance of the composite-modified asphalt, with 300 mesh identified as the optimal particle size that provides the best balance between high-temperature stiffness, low-temperature ductility, and storage stability. When the RHB fineness is fixed at 300 mesh, increasing the RHB content from 0 to 16 wt% markedly enhances the high-temperature performance of the composite asphalt, while its low-temperature performance slightly decreases. Scanning electron microscopy (SEM) analysis reveals that the porous structure and large specific surface area of RHB enable it to form a stable spatial network within the asphalt matrix, thereby improving high-temperature stability. Fourier-transform infrared spectroscopy (FTIR) results show that the incorporation of RHB alters the chemical structure of the asphalt and increases the degree of crosslinking, while thermogravimetry–differential scanning calorimetry (TG-DSC) analysis further confirms that the thermal stability of the composite-modified asphalt is significantly enhanced. Full article

The incorporation of carbon nanotubes (CNT) into cementitious composites has shown strong potential for enhancing mechanical performance. However, conventional dispersion methods, such as ultrasonication and chemical functionalization, are costly, complex, and difficult to scale for construction applications. This study introduces an alternative approach based on the in situ synthesis of CNT on active silica grains, which enables their direct incorporation into mortar formulations. The material was produced via chemical vapor deposition and characterized by scanning electron microscopy, thermogravimetric analysis, energy-dispersive spectroscopy, and Fourier-transform infrared spectroscopy. The resulting nanostructured active silica (NAS) exhibited high carbon content (80.7%) and a 1350% yield, confirming efficient nanotubular deposition. Residual oxygen (9.12%), Mg (0.75%), and Al (0.17%) indicated partial retention of catalytic species, while Fe–Co promoters with Mg–Al modifiers enabled a catalytically active surface favorable to CNT growth. Mortars incorporating NAS restored the flexural strength losses associated with cement replacement by silica, achieving values comparable to the reference mixture and outperforming the silica-only sample; compressive strength increased by ~16.5%. These results demonstrate that NAS promotes effective CNT dispersion at the composite scale without additional dispersion techniques, reduces process complexity, and adds value to commercial silica, providing a scalable route for developing nanostructured cementitious composites for construction applications. Full article

Through Glass Via (TGV) technology has emerged as a promising solution for advanced packaging. While glass offers lower dielectric loss than silicon, its lower thermal conductivity raises concerns about electro-thermal coupling effects in high-power, high-frequency applications. Therefore, this study conducted an electro-thermal co-design of TGV grounded Coplanar Waveguide (CPW) and Radio Frequency (RF) TGV connected CPW structures. A high-power test platform was developed to investigate the electrical and thermal performance of these structures. The temperature distribution mechanism under high-power conditions was revealed. Under high power and high frequency, the decrease in surface conductivity affected by surface state and film layer composition leads to increased loss, triggering temperature rise and forming an electrothermal coupling loop. Under continuous wave operation (5–20 W), the temperature rise reaches 92.4 °C while insertion loss increases by only 0.4 dB. Under pulsed wave operation (25–100 W, 2.5% duty cycle), the temperature rise is merely 2.1 °C with insertion loss increasing by 0.3 dB. The quadruple-redundant design and reduces heat flux density, preventing localized hotspot formation. The pulse intervals suppress thermal accumulation, leading to lower temperature rise. Therefore, continuous wave applications should prioritize thermal management, while pulsed wave applications can focus on electrical performance optimization. Full article

Air pollution remains a major public-health concern, and exposure to particulate matter (PM), particularly PM₁₀ (with a diameter ≤ 10 µm), is associated with adverse respiratory and cardiovascular outcomes. Most research relies on a singular model for PM₁₀ surface estimation. This study is an assessment of a national-scale, daily PM₁₀ estimation framework for Lithuania (2019–2024), using a hybrid machine-learning method that combines Random Forest (RF) and extreme gradient boosting (XGBoost) algorithms. Hourly PM₁₀ observations were aggregated from 18 monitoring stations to obtain daily means and temporal means. The predictors integrated meteorological factors, such as temperature, wind, humidity, and precipitation, to determine satellite-based atmospheric composition from Sentinel-5P Tropospheric Monitoring Instruments (TROPOMI). Atmospheric components include nitrogen dioxide (NO₂), carbon monoxide (CO), sulfur dioxide (SO₂), ozone (O₃), formaldehyde (HCHO), and the absorbing aerosol index (AI). Moderate-Resolution Imaging Spectroradiometers (MODIS) were used to record land-surface temperature and static spatial descriptors, such as elevation, land cover, Normalized Difference Vegetation Index (NDVI), population, and road proximity. The dataset was partitioned temporally into training (70%), validation (20%), and testing (10%). The hybrid model achieved an improved accuracy, compared with single-model baselines, reaching a coefficient of determination (R²) of 0.739 in validation and R² = 0.75 in the tested dataset. Mean absolute error (MAE) was 3.15 µg/m³, and root mean square error (RMSE) was 3.98 µg/m³. The results indicate a slight tendency to overestimate PM₁₀ concentrations at lower concentration levels. Feature-importance analysis revealed that short-term temporal persistence is the key to daily PM₁₀ prediction, while meteorological variables provide secondary contributions. Temporal evaluation, using consecutive two-year windows, revealed a consistent improvement in predictive performance from 2019–2020 to 2023–2024, while station-level analysis showed moderate-to-strong agreement between the predicted and observed PM₁₀ concentrations across monitoring stations, with R² ranging from 0.455 to 0.760. This provides decision-support capabilities for air-quality management, the evaluation of mitigation measures, and integration of air-pollution considerations into sustainable urban planning strategies assessing public-health protection. Full article

The chemical vapor deposition (CVD) method is a key technology for producing silicon carbide (SiC) epitaxial wafers used in high-performance power devices. Defects in the epitaxial wafers, such as triangular, threading dislocations (TDs); basal plane dislocations (BPDs); and stacking faults (SFs), are considered the critical bottleneck determining device performance and long-term reliability. This review aims to systematically elucidate the fundamental physical and chemical principles underlying defect generation during epitaxial growth of SiC by CVD and provide a comprehensive assessment of corresponding defect reduction strategies. Starting from the essential condition of thermodynamic growth, we analyze the main mechanisms of defect formation, including nonequilibrium kinetics, surface reaction kinetics, and the inheritance of substrate defects. Emphasis is placed on discussing the mechanisms and methods for suppressing defect formation through substrate engineering (off-angle design and surface pretreatment), precise control of the growth parameters (C/Si ratio, temperature, gas composition, and so on), as well as advanced post-treatment techniques. This leads to the proposal of practical strategies focusing on substrate engineering and growth parameter optimization toward practical application. Finally, we summarize the inspection techniques and outline future research directions toward intrinsic low-defect-density SiC epitaxial materials for high-voltage applications. Full article

This study investigates the preparation of a composite material by immobilizing Bacillus subtilis on biochar derived from chicken manure biogas residue for the removal of Cr(VI) from wastewater. The results demonstrated that the composite material (Bacillus subtilis immobilized biochar, BIB) achieved a maximum Cr(VI) removal efficiency of 94.1% in a 100 mg/L Cr(VI) solution within 4 h. The chicken manure-derived biochar not only served as an effective carrier for Bacillus subtilis but also enhanced the Cr(VI) removal efficiency through a synergistic effect with the microorganism. Functional groups such as phosphorus, carboxyl, and hydroxyl groups on the biochar surface played a key role in the sorption of Cr(VI). Bacillus subtilis primarily reduced Cr(VI) to Cr(III) by secreting cellular reductases. The combined action of biochar and Bacillus subtilis increased the Cr(VI) removal rate by 13.71% compared to biochar alone. This study presents a promising approach for Cr(VI) remediation in contaminated water and lays a theoretical foundation for the development of composite materials for Cr(VI) reduction. Full article

To address the safety and environmental challenges associated with deep mining, this study investigates the rheological behaviors and pipeline transport characteristics of cemented paste backfill (CPB) using unclassified tailings from a lead–zinc mine. Through the characterization of basic physicochemical properties—including chemical composition, particle size distribution, and specific surface area—combined with L-shaped pipeline simulation tests, the effects of slurry concentration and pipe diameter on rheological parameters and transport resistance were quantitatively analyzed. Furthermore, the mechanical performance and cost-effectiveness of four different cementitious binders were evaluated to identify the optimal material. The results indicate that the unclassified tailings possess a favorable particle size distribution with a significant fine-particle filling effect, making them suitable as backfill aggregates. Slurry concentration was identified as the critical factor influencing rheological performance; a concentration range of 68% to 72% was determined to be optimal, exhibiting superior fluidity and low pipeline resistance conducive to gravity flow. Additionally, increasing the pipe diameter was found to effectively reduce transport difficulty. Based on a comprehensive technical and economic analysis, Kunlun Mountain PO42.5 cement was selected as the optimal binder, achieving the required backfill strength with controlled costs. This study provides a theoretical basis and practical engineering guidance for the design and optimization of deep-well backfill pipeline systems. Full article

A highly effective and economical method to immobilize cadmium in alkaline agricultural soil is urgently needed. Using adsorption kinetic and isotherm experiments, soil incubation tests, and cadmium leaching assays, this study aimed to evaluate the applicability of hydroxyapatite–organic fertilizer composite amendment (HO), individual hydroxylapatite (HA), individual organic fertilizer (OF), sepiolite (SP), and diatomite (DE) to passivate soil cadmium and their passivating effect. In the aqueous phase, HO successfully adsorbed Cd²⁺ onto the surface and has superior potential Cd²⁺ adsorption capacity than OF, DE, and SP, with its adsorption capacity closely approaching that of HA, enabling its use as a passivator in field Cd-contaminated soils. In Cd-contaminated soil, HO effectively lowered the pH from 9.22 to 8.59 at a 5% application rate and changed the aggregate-size distribution of the soil. The increase in the amount of passivator also significantly increased the soil aggregate size. Moreover, the addition of HO significantly improved the extractable contents of Cd in the soil. Compared with the control, the combined amendment decreased TCLP (toxicity leaching procedure test)-extractable Cd by 30.95%, 42.86%, 59.52%, and 69.05% at application rates of 0.5%, 1%, 3%, and 5% (w/w), respectively. These results demonstrate that HO is a highly efficient and low-cost organic–inorganic composite passivator for cadmium-contaminated soils. Full article

Silica-rich rice husk ash (RHA) was upcycled as an inorganic filler to engineer cellulose acetate (CA) films with tunable properties for higher-value sustainable packaging. Composite films were produced by solvent casting, varying RHA loading with and without glycerol plasticization. FTIRconfirmed the chemical integrity of CA and indicated an increase in hydroxyl interactions in glycerol-plasticized films. Optical microscopy showed that RHA progressively induces particle domains and aggregation, while glycerol improves dispersion and surface uniformity. These microstructural effects translated into controllable optical–mechanical trade-offs: neat CA remained highly transparent, whereas RHA reduced transmittance. Glycerol had a minor effect effect on transmittance, indicating that shielding is primarily governed by the ash-derived inorganic domains and tensile testing highlighted an optimal low-filler regime. A small RHA addition maximized strength and stiffness in non-plasticized films. Contact-angle measurements in neutral and alkaline media indicated pH-sensitive wetting, with faster deterioration under alkaline conditions. Thermogravimetric analysis confirmed increased char residue with RHA addition and that glycerol introduces an early mass-loss stage. Overall, the CA/RHA platform offers a simple and potentially scalable route to upcycled, silica-reinforced films, and the formulation of CA and 1.33 wt% RHA (without glycerol) stands out as a robust secondary layer with low transmittance in the UV-Vis range, making it suitable for high-value light-sensitive flexible healthcare packaging, such as protective overwraps or translucent pouches. Full article

The increasing energy demand and global dependence on conventional fuels have resulted in severe greenhouse gas (GHG) emissions, necessitating the development of sustainable bioenergy alternatives. Algal is recognized as a promising feedstock for the production of fourth-generation biofuels. This study optimizes catalytic pyrolysis of Arthrospira platensis for bio-oil production via a dual-bed catalyst system of iron-impregnated dolomite (Fe/DM) and a copper-impregnated spent fluid catalytic cracking catalyst (Cu/sFCC). A face-central composite design (FCCD) and response surface methodology (RSM) were used for the delineation of optimal conditions, ensuring that all experimental tests remained within feasible operating conditions of 500–600 °C, a reaction time of 45–75 min, a N₂ flow rate of 50–200 mL/min, and a catalyst loading of 5–20 wt%. The bio-oil yield was maximized at 39.73 ± 2.86 wt% at 500 °C for 45 min, a N₂ flow of 50 mL/min, and 5 wt% catalyst loading to feedstock with a 0.4:0.6 mass ratio of Fe/DM: Cu/sFCC. The dual-catalysts combined Brønsted and Lewis acid sites enhanced the catalytic activity, which promotes the cleavage of carbon–carbon and carbon–hydrogen bonds, including the mechanism of catalytic pathways such as dehydration, decarboxylation, oligomerization, aromatization, and further cracking reactions, and was successful in converting high-molecular-weight molecules into lighter hydrocarbons and significantly improving product selectivity, demonstrating a highly effective pathway for producing high-quality sustainable biofuel. Full article