Found 497 results
Open Access
Article
02 February 2026Alkaline Leaching Lithium from Spent Carbon Anode and Coupling of Extraction-Carbonization for Cryolite Regeneration
This paper proposes an integrated coupling process of alkali leaching, HBTA-TOPO synergistic extraction, and carbonation for the resource utilization of spent carbon anode (SCA), a typical lithium-bearing industrial solid waste from electrolytic aluminum production, whose lithium content exceeds the ore grade. Compared with conventional acid leaching methods, the adopted alkaline leaching approach features mild reaction conditions, low equipment corrosion risk, and eliminates the volatilization of toxic hydrogen fluoride (HF) gas, thus showing prominent environmental safety advantages. Under the optimal alkaline leaching conditions (NaOH concentration of 10 mol/L, reaction temperature of 90 °C, liquid-to-solid ratio of 10:1, and reaction time of 120 min), the maximum Li+ leaching rate reaches 89.46%. As the leaching process proceeds, lithium in the carbon slag rapidly migrates to the alkaline leaching solution. The Na–Al–F bonds of cryolite (Na3AlF6) and lithium cryolite (Na2LiAlF6) present in the SCA gradually break, and soluble ions such as Na+, Li+, Al3+, and F− enter the solution. High-concentration Na+ reacts with free F− to form sodium fluoride (NaF), which adheres to the SCA, leading to an increase in the sodium-aluminum ratio (Na/Al) of the SCA. The HBTA-TOPO synergistic extraction system is proposed for the extraction and enrichment of lithium in the lithium alkaline leaching solution, and the extraction residue is used to repair and regenerate cryolite. The extraction efficiency of Li+ reaches and the yield of cryolite reaches 81.54% and 76.54%. The molecular ratio of sodium fluoride to aluminum fluoride in synthetic cryolite products is relatively high. This integrated process realizes the efficient recovery of lithium and the high-value regeneration of cryolite from SCA, providing a sustainable technical route for the clean utilization of electrolytic aluminum solid waste. This integrated closed-loop process realizes the simultaneous recovery of lithium and high-value regeneration of cryolite from SCA, which not only mitigates the environmental pollution caused by SCA stacking and the scarcity of lithium resources, but also provides a sustainable technical route for the clean and high-value utilization of electrolytic aluminum solid waste.
Open Access
Article
02 February 2026Topology Optimization for Drone Structure: Comprehensive Workflow Including Conceptual Modeling, Components Preparation and Additive Manufacturing
Payload drones are often limited more by frame weight than by motor power. This work aims to design, optimize, and validate a flat octocopter frame with eight independently driven rotors arranged symmetrically on separate arms. The drone frame design in SOLIDWORKS uses Finite Element Analysis (FEA) and topology optimization to remove material from low-stress regions while keeping the main load paths intact. The final design cuts the frame mass by 37.3% compared to the baseline model and reduces the 3D printing time by about five hours using a Creality K1C printer with Polylactic Acid (PLA) filament. These changes increase the available thrust-to-weight margin for payload without exceeding the allowable stress or deformation limits of the material. The electronic components also identified compatible flight controllers, ESCs, motors, and radio systems to show that the proposed frame can be integrated into a complete multirotor platform. Overall, this work demonstrates a practical approach to designing lighter octocopter frames that are easier to 3D print and can be used more effectively for delivery and inspection missions.
Open Access
Article
30 January 2026Photocatalytic Transformation of Guanine Using Colloidal CdS Nanoparticles
Investigations into the photoinduced reactions of deoxyribonucleic acid (DNA) bases are important for human health. Herein, we have synthesized colloidal CdS nanoparticles by a method reported in the literature. The mean particle diameter of the semiconductor was about 55 nm. The colloidal CdS particles were used as a photocatalyst to investigate the organic transformation of guanine (2-amino-6-oxopurine). The products of the semiconductor-induced reaction were analyzed by liquid chromatography-mass chromatography (LC-MS) measurements. The solitary product of the photocatalytic reaction of guanine was revealed as 2,5-diamino-4H-imidazol-4-one. The likely reaction pathway for the formation of the product has been presented. To our understanding, the present work is the first account on the mechanistic aspects of the semiconductor-induced photocatalytic reaction of guanine.
Open Access
Article
28 January 2026Enhanced High-Temperature Oxidation Resistance of Refractory High-Entropy Alloys Al-Cr-Mo-Ta-Ti by Aluminizing Using Pack Cementation
Refractory high-entropy alloys (RHEAs) show promising properties for applications as structural materials in high-temperature applications, such as high solidus temperature and high strength. Improving their density, oxidation resistance, and room temperature ductility are still the aims of research in alloy development. In this study, Al-rich diffusion coatings by pack cementation are developed for three different alloys in the system Al-Cr-Mo-Ta-Ti in order to improve their high-temperature oxidation resistance. Equimolar AlCrMoTaTi, Al-rich Al3CrMoTaTi, and Ti-rich AlCrMoTaTi3 are synthesized by vacuum arc melting with subsequent milling to powder, consolidation to bulk material by field-assisted sintering technology/spark plasma sintering (FAST/SPS), and homogenization heat treatment. The applied aluminizing coatings are investigated by gravimetry, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Experimental analyses are supplemented by CALPHAD simulations. Compact, uniform, and adhesive Al-rich diffusion coatings are produced on all three substrate RHEAs and exhibit single-layered D022 Al3(Cr,Mo,Ta,Ti) intermetallic compound analogous to Al3Ti in the binary Al-Ti system. Isothermal oxidation at 1000 °C for 48 h in ambient air results in the formation of 1–2 µm thin protective single-layered alumina scale—in contrast to multi-layered oxide scales in uncoated condition—and mass gains as low as binary Al3Ti and Ni-based superalloys.
Open Access
Perspective
28 January 2026The Double Face of Exosomes Derived from Mesenchymal Stromal Cells in Fibrotic Lung Diseases: Pathology Contribution or Treatment?
Several studies have attempted to clarify the role of exosomes and/or microvesicles derived from mesenchymal stromal cells (MSCs) (collectively indicated as extracellular vesicles: MSCs-EVs) in pulmonary fibrosis. Depending on their origin and on the micro-environmental context, MSCs-EVs may support or attenuate the fibrotic invasion of the lung, a hallmark of all Interstitial Lung Diseases (ILDs). Indeed, EVs have emerged as pivotal intercellular mediators and their potential diagnostic and therapeutic applications have been suggested. We aim here to elucidate the dual role of MSCs-derived exosomes and microvesicles: the contribution to pulmonary fibrosis progression, exerted by the MSCs-EVs originated from resident MSCs, or the potential therapeutic activity of those generated from healthy MSCs. Actually, MCSs-EVs appear as the frontiers of cell-free therapy and nano-medicine research in a great number of pre-clinical studies, but developments are needed to optimize and standardize their isolation, production and delivery. Interestingly, since the respiratory system directly communicates with the external environment, lung treatment could be approached by MSCs-EVs nebulization as a preferential administration route, integrating targeted pulmonary delivery with an enhanced patient’s compliance. Hence MSCs-EVs may contribute to ILD pathogenesis, display a potential as biomarkers, and still hold promise as therapeutic agents to reduce lung fibrosis. However further researches are needed to validate their clinical application.
Open Access
Review
27 January 2026Emergent Superorganisms: Grass Rings Shaped by Individual Growth and Mortality
The grass ring phenomenon remains an interesting and enduring puzzle. Previous research has proposed various mechanisms, including Environmental stress and physical disturbance, Nutrient and water depletion, and the Self-Organization hypothesis, to explain ring formation. However, this process is highly complex and dynamic, hindering the development of a unified theory. This is primarily because grass rings of different origins, and even those at different developmental stages, are influenced by diverse factors. Furthermore, existing studies have often been limited to isolated cases, which highlights the need for more comprehensive, global-scale studies. Through a systematic analysis of publications, this review proposes three claims. First, they are classified based on genetic origin into single and multiple individual origins, which align with formation driven primarily by death-based and growth-based formation modes, respectively. Second, the grass ring is essentially a superorganism. Third, although grass rings are globally widespread, their formation mechanisms in regions above 4000 m remain elusive. Future research should prioritize key directions, including quantifying complete life cycles and elucidating mechanisms of high-altitude formation. This requires establishing international monitoring networks that integrate multi-omics with hyperspectral remote sensing to predict how grass rings develop under global climate change.
Open Access
Article
26 January 2026Enhanced Stability of Nickel Phyllosilicate Anchored Ni/SiO2 Catalyst for Liquid-Phase Hydrogenation and Hydrodeoxygenation
The aggregation and leaching of nanoparticles often reduce catalytic activity and hinder the long-term application of catalysts. Here, we synthesis a hollow Ni/SiO2-AEH catalyst with small Ni nanoparticles (NPs) encapsulated by nickel phyllosilicate (NiPS) via an ammonia evaporation-hydrothermal method. Compared with the Ni/SiO2-AE only synthesized via ammonia evaporation method, the Ni/SiO2-AEH catalyst after further hydrothermal treatment possesses more nickel phyllosilicate (NiPS) species, which enhances the stability of Ni NPs through the strong metal-support bonding (Si–O–Ni) in NiPS. By controlling the size of Ni NPs to 3.6 nm along with the presence of NiPS, we find that Ni/SiO2-AEH displays superior catalytic performance for maleic anhydride (MA) hydrogenation and vanillin hydrodeoxygenation, achieving yields of 97% for succinic anhydride (SA) and 99% for 2-methoxy-4-methylphenol (MMP), respectively. Importantly, the deactivation of Ni/SiO2-AEH is remarkably suppressed, with only a slight decrease in activity after five or six runs. The excellent catalytic activity and stability of phyllosilicate materials imply an extensive application in other industrial catalytic reactions.
Open Access
Review
26 January 2026Synergistic Natural Products in Anti-Ageing: Mechanistic Insights, Experimental Evidence, and Translational Perspectives
Ageing is characterised by a progressive decline in physiological function driven by oxidative stress, chronic inflammation, and metabolic imbalance. Natural products contain diverse bioactive compounds capable of regulating these interconnected processes through convergent molecular pathways. This review synthesises current evidence across six major classes of natural bioactives, including polyphenols, terpenoids, polyamines, polysaccharides, fatty acids, and bioactive peptides, and examines their roles within metabolic, redox, inflammatory, and epigenetic networks. Individually, these compounds enhance mitochondrial function, modulate AMP-activated protein kinase (AMPK)–sirtuin 1 (SIRT1)–mechanistic target of rapamycin complex 1 (mTORC1) signalling, activate the nuclear factor erythroid 2-related factor 2 (Nrf2)–antioxidant response element (ARE) antioxidant pathway, suppress nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) activation, and improve cellular stress resilience. When used in combination, they exhibit synergistic interactions that amplify antioxidant, anti-inflammatory, and metabolic benefits, resulting in measurable improvements in lifespan and healthspan. Quantitative analyses demonstrate that rationally designed combinations achieve approximately 20–35 percent greater efficacy than single agents, reflecting coordinated multi-target reinforcement rather than simple additive effects. Overall, these insights highlight the mechanistic rationale, experimental evidence, and translational potential of synergistic natural bioactives as promising strategies for promoting healthy ageing and mitigating age-related decline.
Open Access
Article
26 January 2026Investigating the Interplay of Springshed Phenomenon and Its Crucial Role in Fostering Sustainable Practices and Community Resilience: Reflection from the Indian Himalayan Regions
This study examines the critical role of springsheds in fostering resilient communities and sustainable practices in the Indian Himalayan regions, focusing on Kalimpong I (Kalimpong) and Bhurung (Sikkim). The research addresses the pressing environmental challenges, particularly resource depletion and water scarcity, that threaten these ecologically sensitive areas. By integrating physical, environmental, and socio-economic analyses, the study compares the spring water quality, utility, and mobility in the two springsheds. It also identifies obstacles residents face in accessing these water sources. Utilizing mixed methods, including field surveys, in-depth interviews, GIS-based mapping, and water quality analysis, the study reveals the indispensable role of springs in daily life, providing essential water for drinking, agriculture, and domestic use. The findings emphasize the need to integrate traditional knowledge with sustainable practices, such as rainwater harvesting and afforestation, to enhance community resilience. This research highlights the importance of community-driven approaches to environmental sustainability, offering valuable insights for similar ecological settings worldwide.
Open Access
Article
21 January 2026Milling Mechanism of Sheet Fiberglass Plastic by a Tungsten Carbide Tool with Diamond and Diamond-like Wear-Resistant Coatings
The study focuses on identifying the specific mechanisms of the FR4 fiberglass composite milling process using tungsten carbide end mills with wear-resistant diamond-like and diamond coatings. The processing was carried out at cutting speeds from 115 to 300 m/min and feed of 0.075 and 0.15 mm/tooth. At the same time, the vibroacoustic signal was recorded in three formats: changes in the RMS value and the amplitude of the acoustic emission in the low-frequency and high-frequency ranges, as well as the parameter Kf, which is the ratio of the RMS amplitudes of the signals in the low-frequency and high-frequency ranges. It is shown that the coating material has a predominant effect on the surface roughness. The minimum roughness value was RA = 0.2 µm for the case of a diamond-coated tool. In addition, the coating improves processing performance by increasing the cutting speed for tools with DLC by 1.3 times and for tools with diamond coating by 1.7 times, provided that the RA increases slightly but does not exceed 0.36 µm. When processed with an uncoated instrument, the mill captures the fiber, bends it and breaks it into bundles, creating grooves. The mechanism of glass fiber destruction by a DLC mill is similar, with the difference that the length of the fragmented fiber sections is noticeably reduced due to reduced friction. The mechanism of cutting fiberglass with a diamond-coated milling cutter is significantly different. There are characteristic scratches on the worn sections of the fiber, and there are no signs of destruction of the composite between the matrix and the fiber. Studies of vibration signals have shown that frequency ranges up to 20 kHz and from 33 to 48 kHz are informative enough to diagnose the fiberglass milling process. The most significant values of the Kf parameter were observed at large amplitudes of low-frequency vibrations, typical for processing with uncoated and DLC milling cutters. The lowest Kf values were obtained using diamond-coated milling cutters. A correlation was found between the values of the Kf parameter and the roughness values of the treated end surface of the fiberglass plate.
