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Keywords = Cu-W composites

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39 pages, 8119 KiB  
Article
Magmatic Redox Evolution and Porphyry–Skarn Transition in Multiphase Cu-Mo-W-Au Systems of the Eocene Tavşanlı Belt, NW Türkiye
by Hüseyin Kocatürk, Mustafa Kumral, Hüseyin Sendir, Mustafa Kaya, Robert A. Creaser and Amr Abdelnasser
Minerals 2025, 15(8), 792; https://doi.org/10.3390/min15080792 - 28 Jul 2025
Viewed by 310
Abstract
This study explores the magmatic and hydrothermal evolution of porphyry–skarn–transitional Cu-Mo-W-Au systems within the Nilüfer Mineralization Complex (NMC), located in the westernmost segment of the Eocene Tavşanlı Metallogenic Belt, NW Türkiye. Through integration of field data, whole-rock geochemistry, Re–Os molybdenite dating, and amphibole–biotite [...] Read more.
This study explores the magmatic and hydrothermal evolution of porphyry–skarn–transitional Cu-Mo-W-Au systems within the Nilüfer Mineralization Complex (NMC), located in the westernmost segment of the Eocene Tavşanlı Metallogenic Belt, NW Türkiye. Through integration of field data, whole-rock geochemistry, Re–Os molybdenite dating, and amphibole–biotite mineral chemistry, the petrogenetic controls on mineralization across four spatially associated mineralized regions (Kirazgedik, Güneybudaklar, Kozbudaklar, and Delice) were examined. The earliest and thermally most distinct phase is represented by the Kirazgedik porphyry system, characterized by high temperature (~930 °C), oxidized quartz monzodioritic intrusions emplaced at ~2.7 kbar. Rising fO2 and volatile enrichment during magma ascent facilitated structurally focused Cu-Mo mineralization. At Güneybudaklar, Re–Os geochronology yields an age of ~49.9 Ma, linking Mo- and W-rich mineralization to a transitional porphyry–skarn environment developed under moderately oxidized (ΔFMQ + 1.8 to +0.5) and hydrous (up to 7 wt.% H2O) magmatic conditions. Kozbudaklar represents a more reduced, volatile-poor skarn system, leading to Mo-enriched scheelite mineralization typical of late-stage W-skarns. The Delice system, developed at the contact of felsic cupolas and carbonates, records the broadest range of redox and fluid compositions. Mixed oxidized–reduced fluid signatures and intense fluid–rock interaction reflect complex, multistage fluid evolution involving both magmatic and external inputs. Geochemical and mineralogical trends—from increasing silica and Rb to decreasing Sr and V—trace a systematic evolution from mantle-derived to felsic, volatile-rich magmas. Structurally, mineralization is controlled by oblique fault zones that localize magma emplacement and hydrothermal flow. These findings support a unified genetic model in which porphyry and skarn mineralization styles evolved continuously from multiphase magmatic systems during syn-to-post-subduction processes, offering implications for exploration models in the Western Tethyan domain. Full article
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20 pages, 10028 KiB  
Article
The Fabrication of Cu2O-u/g-C3N4 Heterojunction and Its Application in CO2 Photoreduction
by Jiawei Lu, Yupeng Zhang, Fengxu Xiao, Zhikai Liu, Youran Li, Guiyang Shi and Hao Zhang
Catalysts 2025, 15(8), 715; https://doi.org/10.3390/catal15080715 - 27 Jul 2025
Viewed by 421
Abstract
Over efficient photocatalysts, CO2 photoreduction typically converts CO2 into low-carbon chemicals, which serve as raw materials for downstream synthesis processes. Here, an efficient composite photocatalyst heterojunction (Cu2O-u/g-C3N4) has been fabricated to reduce CO2. [...] Read more.
Over efficient photocatalysts, CO2 photoreduction typically converts CO2 into low-carbon chemicals, which serve as raw materials for downstream synthesis processes. Here, an efficient composite photocatalyst heterojunction (Cu2O-u/g-C3N4) has been fabricated to reduce CO2. Graphitic carbon nitride (g-C3N4) was synthesized via thermal polymerization of urea at 550 °C, while pre-dispersed Cu2O derived from urea pyrolysis (Cu2O-u) was prepared by thermal reduction of urea and CuCl2·2H2O at 180 °C. The heterojunction Cu2O-u/g-C3N4 was subsequently constructed through hydrothermal treatment at 180 °C. This heterojunction exhibited a bandgap of 2.10 eV, with dual optical absorption edges at 485 nm and above 800 nm, enabling efficient harvesting of solar light. Under 175 W mercury lamp irradiation, the heterojunction catalyzed liquid-phase CO2 photoreduction to formic acid, acetic acid, and methanol. Its formic acid production activity surpassed that of pristine g-C3N4 by 3.14-fold and TiO2 by 8.72-fold. Reaction media, hole scavengers, and reaction duration modulated product selectivity. In acetonitrile/isopropanol systems, formic acid and acetic acid production reached 579.4 and 582.8 μmol·h−1·gcat−1. Conversely, in water/triethanolamine systems, methanol production reached 3061.6 μmol·h−1·gcat−1, with 94.79% of the initial conversion retained after three cycles. Finally, this work ends with the conclusions of the CO2 photocatalytic reduction to formic acid, acetic acid, and methanol, and recommends prospects for future research. Full article
(This article belongs to the Section Photocatalysis)
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19 pages, 9988 KiB  
Article
Research on Modification Technology of Laser Cladding Stellite6/Cu Composite Coating on the Surface of 316L Stainless Steel Plow Teeth
by Wenhua Wang, Qilang He, Wenqing Shi and Weina Wu
Micromachines 2025, 16(7), 827; https://doi.org/10.3390/mi16070827 - 20 Jul 2025
Viewed by 307
Abstract
Plow loosening machines are essential agricultural machinery in the agricultural production process. Improving the surface strengthening process and extending the working life of the plow teeth of the plow loosening machine are of great significance. In this paper, the preparation of Stellite6/Cu composite [...] Read more.
Plow loosening machines are essential agricultural machinery in the agricultural production process. Improving the surface strengthening process and extending the working life of the plow teeth of the plow loosening machine are of great significance. In this paper, the preparation of Stellite6/Cu composite coating on the surface of 316L steel substrate intended for strengthening the plow teeth of a plow loosening machine using laser cladding technology was studied. The influence of different laser process parameters on the microstructure and properties of Stellite6/Cu composite coating was investigated. The composite coating powder was composed of Stellite6 powder with a different weight percent of copper. Microstructural analysis, phase composition, elemental distribution, microhardness, wear resistance, and corrosion resistance of the composite coatings on the plow teeth were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness testing, energy dispersive spectroscopy (EDS), friction and wear testing, and electrochemical workstation measurements. The results showed that (1) When the laser power was 1000 W, the average hardness of the prepared Stellite6/Cu composite layer achieved the highest hardness, approximately 1.36 times higher than the average hardness of the substrate, and the composite coating prepared exhibited the best wear resistance; (2) When the scanning speed was 800 mm/min, the composite coating exhibited the lowest average friction coefficient and the optimal corrosion resistance in a 3.5% wt.% NaCl solution with a self-corrosion current density of −7.55 µA/cm2; (3) When the copper content was 1 wt.%, the composite coating achieved the highest average hardness with 515.2 HV, the lowest average friction coefficient with 0.424, and the best corrosion resistance with a current density of −8.878 µA/cm2. Full article
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14 pages, 4290 KiB  
Article
Multifunctional Green-Synthesized Cu2O-Cu(OH)2 Nanocomposites Grown on Cu Microfibers for Water Treatment Applications
by Hala Al-Jawhari, Nuha A. Alhebshi, Roaa Sait, Reem Altuwirqi, Laila Alrehaili, Noorah Al-Ahmadi and Nihal Elbialy
Micro 2025, 5(3), 33; https://doi.org/10.3390/micro5030033 - 5 Jul 2025
Viewed by 358
Abstract
Free-standing copper oxide (Cu2O)-copper hydroxide (Cu(OH)2) nanocomposites with enhanced catalytic and antibacterial functionalities were synthesized on copper mesh using a green method based on spinach leaf extract and glycerol. EDX, SEM, and TEM analyses confirmed the chemical composition and [...] Read more.
Free-standing copper oxide (Cu2O)-copper hydroxide (Cu(OH)2) nanocomposites with enhanced catalytic and antibacterial functionalities were synthesized on copper mesh using a green method based on spinach leaf extract and glycerol. EDX, SEM, and TEM analyses confirmed the chemical composition and morphology. The resulting Cu2O-Cu(OH)2@Cu mesh exhibited notable hydrophobicity, achieving a contact angle of 137.5° ± 0.6, and demonstrated the ability to separate thick oils, such as HD-40 engine oil, from water with a 90% separation efficiency. Concurrently, its photocatalytic performance was evaluated by the degradation of methylene blue (MB) under a weak light intensity of 5 mW/cm2, achieving 85.5% degradation within 30 min. Although its application as a functional membrane in water treatment may raise safety concerns, the mesh showed significant antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria under both dark and light conditions. Using the disk diffusion method, strong bacterial inhibition was observed after 24 h of exposure in the dark. Upon visible light irradiation, bactericidal efficiency was further enhanced—by 17% for S. aureus and 2% for E. coli. These findings highlight the potential of the Cu2O-Cu(OH)2@Cu microfibers as a multifunctional membrane for industrial wastewater treatment, capable of simultaneously removing oil, degrading organic dyes, and inactivating pathogenic bacteria through photo-assisted processes. Full article
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21 pages, 2754 KiB  
Article
Exploring Growth Phase Effect on Polysaccharide Composition and Metal Binding Properties in Parachlorella hussii
by Karima Guehaz, Zakaria Boual, Giulia Daly, Matilde Ciani, Hakim Belkhalfa and Alessandra Adessi
Polysaccharides 2025, 6(3), 58; https://doi.org/10.3390/polysaccharides6030058 - 2 Jul 2025
Viewed by 422
Abstract
Microalgae-based bioremediation is increasingly recognized as a sustainable, efficient, and straightforward technology. Despite this growing interest, the potential of Parachlorella hussii for metal biosorption remains underexplored. This study is the first report evaluating the metal biosorption activity in Parachlorella hussii ACOI 1508 (N9), [...] Read more.
Microalgae-based bioremediation is increasingly recognized as a sustainable, efficient, and straightforward technology. Despite this growing interest, the potential of Parachlorella hussii for metal biosorption remains underexplored. This study is the first report evaluating the metal biosorption activity in Parachlorella hussii ACOI 1508 (N9), highlighting the impact of the culture age on the monosaccharide composition and its correlation to the metal binding capacity. The capsular strain (N9) was isolated from the hypersaline ecosystem—Lake Chott Aïn El-Beida—in southeastern Algeria. Cultivated in Bold’s Basal medium, the strain produced 0.807 ± 0.059 g L−1 of RPSs and 1.975 ± 0.120 g L−1 of CPSs. Biochemical analysis of the extracts revealed a high total sugar content (% w/w) that ranged from 62.98 ± 4.87% to 95.60 ± 87% and a low protein content (% w/w) that ranged from 0.49 ± 0.08% to 1.35 ± 0.69%, with RPS-D7 and RPS-D14 having high molecular weight (≥2 MDa). HPLC-based monosaccharide characterization demonstrated compositional differences between the exponential and stationary phases, with rhamnose dominating (~55%) in RPS-D14 and with the presence of uronic acids comprising 7–11.3%. Metal removal efficiency was evaluated using the whole biomass in two growth phases. Copper uptake exhibited the highest capacity, reaching 18.55 ± 0.61 mg Cu g−1 DW at D14, followed by zinc removal with 6.52 ± 0.61 mg Zn g−1 DW. Interestingly, removal efficiencies increased to about twofold during the stationary phase, reaching 51.15 ± 1.14% for Cu, 51.08 ± 3.35% for Zn, and 36.55 ± 3.09% for Ni. The positive results obtained for copper/zinc removal highlight the biosorption potential of P. hussii, and notably, we found that the metal removal capacity significantly improved with culture age—a parameter that has been poorly investigated in prior studies. Furthermore, we observed a growth phase-dependent modulation in monosaccharide composition, which correlated with enhanced functional properties of the excreted biomolecules involved in biosorption. This metabolic adjustment suggests an adaptive response that may contribute to the species’ effectiveness in heavy metal uptake, underscoring its novelty and biotechnological relevance. Full article
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30 pages, 3838 KiB  
Article
Evidence of Organ-Specific Metal Accumulation: ICP-MS Elemental Analysis of Autopsy Tissues of Tobacco Smokers
by Wojciech Flieger, Przemysław Niedzielski, Zofia Wojciechowska, Aleksandra Proch, Jędrzej Proch, Alicja Forma, Andrzej Torbicz, Dariusz Majerek, Grzegorz Teresiński, Jacek Baj, Ryszard Maciejewski and Jolanta Flieger
Int. J. Mol. Sci. 2025, 26(13), 6368; https://doi.org/10.3390/ijms26136368 - 2 Jul 2025
Viewed by 386
Abstract
Cigarette smoking exposes individuals to numerous toxic substances, including heavy metals. Smokers are at risk due to the accumulation of these substances in various tissues. Objective: To compare the concentrations of 41 elements in 11 brain regions, the spinal cord, the bronchial, the [...] Read more.
Cigarette smoking exposes individuals to numerous toxic substances, including heavy metals. Smokers are at risk due to the accumulation of these substances in various tissues. Objective: To compare the concentrations of 41 elements in 11 brain regions, the spinal cord, the bronchial, the lungs, and the liver in smokers (n = 11) and non-smokers (n = 17). Elemental composition was determined by ICP-MS after wet digestion in a microwave system. The following toxic elements were detected at levels of µg/g w.w.: Al, Cd, Pb, Ba, As, Ni, and Tl. Significantly higher concentrations of Al were detected in bronchial and lung, and more Pb, Tl, and rare earth elements were detected in the liver of smokers compared to non-smokers. In addition, smokers had significantly lower concentrations of essential elements involved in antioxidant defense, such as Cu, in liver tissue (p = 0.033). The brain and spinal cord in smokers and non-smokers were similar in terms of chemical composition, except the insula, where smokers had greater Al accumulation (p = 0.030), the precentral gyrus, where higher amounts of As, Cd, and Mn were detected, and the septal nucleus accumbens, which preferentially accumulated Cd in smokers; however, the p-values indicate that these differences were not statistically significant. Most brain areas of smokers were characterized by higher Na content (p < 0.05). These findings prove the long-term effects of smoking, demonstrating the bioaccumulation of toxic elements, the increased levels of rare earth elements in the liver, decreased levels of elements involved in the body’s antioxidant defense, and disruption of sodium homeostasis in the brain of smokers. Full article
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23 pages, 23602 KiB  
Article
Exploration of the Supercapacitive Performance of 3D Flower-like Architecture of Quaternary CuNiCoZnO Developed on Versatile Substrates
by Priya G. Gaikwad, Nidhi Tiwari, Rajanish K. Kamat, Sadaf Jamal Gilani, Sagar M. Mane, Jaewoong Lee and Shriniwas B. Kulkarni
Micromachines 2025, 16(6), 645; https://doi.org/10.3390/mi16060645 - 28 May 2025
Viewed by 450
Abstract
The demand for high-performance supercapacitors has driven extensive research into novel electrode materials with superior electrochemical properties. This study explores the supercapacitive behavior of quaternary CuNiCoZnO (CNCZO) films engineered into a three-dimensional (3D) flower-like morphology and developed on versatile substrates, including carbon cloth, [...] Read more.
The demand for high-performance supercapacitors has driven extensive research into novel electrode materials with superior electrochemical properties. This study explores the supercapacitive behavior of quaternary CuNiCoZnO (CNCZO) films engineered into a three-dimensional (3D) flower-like morphology and developed on versatile substrates, including carbon cloth, stainless steel mesh, and nickel foam. The unique structural design, comprising interconnected nanosheets, enhances the electroactive surface area, facilitates ion diffusion, and improves charge storage capability. The synergistic effect of the multi-metallic composition contributes to remarkable electrochemical characteristics, including high specific capacitance, excellent rate capability, and outstanding cycling stability. Furthermore, the influence of different substrates on the electrochemical performance is systematically investigated to optimize material–substrate interactions. Electrochemical evaluations reveal outstanding specific capacitance values of 2318.5 F/g, 1993.7 F/g, and 2741.3 F/g at 2 mA/cm2 for CNCZO electrodes on stainless steel mesh, carbon cloth, and nickel foam, respectively, with capacitance retention of 77.3%, 95.7%, and 86.1% over 5000 cycles. Furthermore, a symmetric device of CNCZO@Ni exhibits a peak specific capacitance of 67.7 F/g at a current density of 4 mA/cm2, a power density of 717.4 W/kg, and an energy density of 25.6 Wh/kg, maintaining 84.5% stability over 5000 cycles. The straightforward synthesis of CNCZO on multiple substrates presents a promising route for the development of flexible, high-performance energy storage devices. Full article
(This article belongs to the Special Issue Energy Conversion and Storage Devices: Materials and Applications)
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16 pages, 8657 KiB  
Article
Tailoring Microstructure and Properties of W-Mo-Cu Composites Fabricated via Infiltration Sintering: Effects of Graphene Addition and Skeleton Relative Density
by Jinwen Cai, Qiaoling Jiang, Keqin Feng and Hongling Zhou
Materials 2025, 18(11), 2539; https://doi.org/10.3390/ma18112539 - 28 May 2025
Viewed by 391
Abstract
W-Mo-Cu composites show promise for advanced applications, but their properties require optimization. In this study, a novel approach utilizing Cu-coated graphene (Cu@Gr) reinforcement with skeleton relative density adjustment was employed to tailor the microstructure and properties of W-Mo-Cu composites fabricated via infiltration sintering [...] Read more.
W-Mo-Cu composites show promise for advanced applications, but their properties require optimization. In this study, a novel approach utilizing Cu-coated graphene (Cu@Gr) reinforcement with skeleton relative density adjustment was employed to tailor the microstructure and properties of W-Mo-Cu composites fabricated via infiltration sintering (1300 °C, 1.5 h). The results revealed that Cu@Gr significantly promoted sintering densification, modified the phase composition, and enhanced the properties of the composite. Specifically, the addition of 0.4 wt.% Cu@Gr resulted in a relative density of 98% for the composite, representing an 8% increase compared to the material without Cu@Gr. Furthermore, when higher amounts of Cu@Gr were incorporated, the composite consistently exhibited a high degree of densification. In addition to the primary W, Mo, and Cu phases, molybdenum carbide, Mo2C, was formed at 0.4 wt.% Cu@Gr, with its content rising proportionally to graphene dosage. Notably, the composite containing 0.6 wt.% Cu@Gr exhibits the highest thermal conductivity and electrical conductivity, showing 64% and 73% increases, respectively, versus Cu@Gr-free samples. Additionally, although W-Mo green compact density variations (73–85%) did not compromise graphene-induced densification, a higher green compact density reduced the thermal/electrical conductivities but increased the hardness. These findings demonstrate that controlled Cu@Gr incorporation and green compact optimization synergistically improve the properties of W-Mo-Cu composites, providing insights into high-performance material design. Full article
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14 pages, 1557 KiB  
Article
Lignin Extracted from Green Coconut Waste Impregnated with Sodium Octanoate for Removal of Cu2+ in Aqueous Solution
by Jéssyca E. S. Pereira, Eduardo L. Barros Neto, Lindemberg J. N. Duarte, Ruan L. S. Ferreira, Ricardo P. F. Melo and Paula F. P. Nascimento
Processes 2025, 13(5), 1590; https://doi.org/10.3390/pr13051590 - 20 May 2025
Viewed by 649
Abstract
Investigating viable processes for the use of lignocellulosic biomass in clean fuels and high-value-added chemical products is essential for sustainable development. Large amounts of lignin are available every year as by-products of the paper and biorefinery industries, causing a series of problems, particularly [...] Read more.
Investigating viable processes for the use of lignocellulosic biomass in clean fuels and high-value-added chemical products is essential for sustainable development. Large amounts of lignin are available every year as by-products of the paper and biorefinery industries, causing a series of problems, particularly environmental ones. Its structure and composition make lignin compatible with the concept of sustainability, since it can be used to produce new chemical products with high added value. As such, this study aims to extract lignin from green coconut fiber (LIG), with the subsequent impregnation of a sodium-octanoate-based surfactant (LIG-SUR), and determine its applicability as an adsorbent for removing copper ions from synthetic waste. To this end, the green coconut fiber lignocellulosic biomass was initially subjected to alkaline pre-treatment with 2% (w/v) sodium hydroxide in an autoclave. Next, the surface of the lignin was modified by impregnating it with sodium octanoate, synthesized from the reaction of octanoic acid and NaOH. The physical and chemical traits of the lignin were studied before and after surfactant impregnation, as well as after copper ion adsorption. The lignin was analyzed by X-ray fluorescence (XRF), Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The adsorption tests were carried out using lignin pre-treated with surfactant in a batch system, where the effects of pH and adsorbent concentration were investigated. XRF and SEM analyses confirmed surfactant impregnation, with Na2O partially replaced by CuO after Cu2+ adsorption. FTIR analysis revealed shifts in O–H, C–H, C=O, and C=C bands, indicating electrostatic interactions with lignin. Adsorption kinetics followed the pseudo-second-order model, suggesting chemisorption, with equilibrium reached in approximately 10 and 60 min for LIG-SUR and LIG, respectively. The Langmuir model best described the isotherm data, indicating monolayer adsorption. LIG-SUR removed 91.57% of Cu2+ and reached a maximum capacity of 30.7 mg·g−1 at 25 °C and a pH of 6. The results of this research showed that pre-treatment with NaOH, followed by impregnation with surfactant, significantly increased the adsorption capacity of copper ions in solution. This technique is a viable and sustainable alternative to the traditional adsorbents used to treat liquid waste. In addition, by using green coconut fiber lignin more efficiently, the research contributes to adding value to this material and strengthening practices in line with the circular economy and environmental preservation. Full article
(This article belongs to the Special Issue Emerging Technologies in Solid Waste Recycling and Reuse)
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29 pages, 5916 KiB  
Article
Metal Fingerprints of Eocene Rhyolite Magmas Coincident with Carlin-Type Gold Deposition in Nevada USA
by Celestine N. Mercer, Hannah R. Babel, Cameron M. Mercer and Albert H. Hofstra
Minerals 2025, 15(5), 479; https://doi.org/10.3390/min15050479 - 4 May 2025
Viewed by 574
Abstract
Eocene magmatic systems contemporaneous with world-class Carlin-type Au deposits in Nevada (USA) have been proposed by some researchers as a key ingredient for Au mineralization, though evidence conclusively demonstrating their genetic relationship remains tenuous. This study provides the first direct evidence of the [...] Read more.
Eocene magmatic systems contemporaneous with world-class Carlin-type Au deposits in Nevada (USA) have been proposed by some researchers as a key ingredient for Au mineralization, though evidence conclusively demonstrating their genetic relationship remains tenuous. This study provides the first direct evidence of the pre-eruptive metal budget of volatile- and metal-charged silicic magmas coincident in time (~41 to 34 Ma) and space (within 5 km) with Carlin-type Au deposits. We characterize the pre-eruptive metal fingerprints of these diverse magmatic systems to assess their potential as sources of metals for Carlin-type Au mineralization. Metal abundances from quartz-hosted melt inclusions (Au, Te, Ag, Sb, Tl, Mo, W, Sn, As, Pb, Co, Cu, Ni, and Zn) characterized in situ by SHRIMP-RG and LA-ICP-MS represent our best (and only) estimates for the pre-eruptive metal budget in these systems. Median metal concentrations are generally within one order of magnitude of average upper crust and average continental rhyolite values. But there are two notable exceptions, with median Au contents extending >1 order of magnitude higher than average upper crust and median Cu contents ranging >1 order of magnitude lower than upper crust. Despite this, melts contain lower Au/Cu (<0.1), Au/Ag (<5), and Au/Tl (<0.3) than most ore-grade Carlin-type rock samples and quartz-hosted fluid inclusions, regardless of their age and timing relative to nearby Carlin-type Au mineralization. The metal fingerprints of these magmatic systems, defined both by traditional and multivariate compositional data analysis techniques, are distinct from one another. Yet none are particularly specialized, e.g., high Au/Cu, in terms of being ideal ingredients as postulated by magmatic models for Carlin-type Au mineralization. Magmatic Au contents do not appear to be correlated with rhyolite “flavors” in the way that Cu, Sn, and Nb contents are. Fluid/melt partitioning modeling and magma volume estimates support the idea that a diverse array of non-specialized silicic magmas could feasibly contribute some or potentially all of the Au, Ag, and Cu in Carlin-type systems. The compositional diversity among contemporaneous magmatic systems could possibly contribute to some of the diversity observed across Carlin-type Au districts in Nevada. Full article
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20 pages, 6353 KiB  
Article
Effects of Wood Ash Fertilizer on Element Dynamics in Soil Solution and Crop Uptake
by Chuanzhen Jian, Toru Hamamoto, Chihiro Inoue, Mei-Fang Chien, Hiroshi Naganuma, Takehito Mori, Akihiro Sawada, Masafumi Hidaka, Hiroyuki Setoyama and Tomoyuki Makino
Agronomy 2025, 15(5), 1097; https://doi.org/10.3390/agronomy15051097 - 30 Apr 2025
Cited by 1 | Viewed by 1742
Abstract
Wood ash, a byproduct of woody biomass power generation, has potential as an alternative K fertilizer due to its high K content and pH-raising properties. However, concerns remain about heavy metal contaminants like Cr and the limited understanding of element dynamics in soil–solution–crop [...] Read more.
Wood ash, a byproduct of woody biomass power generation, has potential as an alternative K fertilizer due to its high K content and pH-raising properties. However, concerns remain about heavy metal contaminants like Cr and the limited understanding of element dynamics in soil–solution–crop systems after wood ash’s application. This study examined the effects of 1% (w/w) wood ash on element dynamics and komatsuna (Brassica rapa var. perviridis) uptake in low-K soil through a pot experiment. XRD was used to analyze mineral composition, SEM-EDS to observe surface and elemental properties, and XANES to examine Cr speciation in wood ash. Soil solution analysis covered macro- and micronutrients, heavy metals, anions, pH, and DOC, while crop element concentrations and aboveground dry weight were also quantified. The chemical speciation of Cu and Cr in a soil solution was modeled using Visual MINTEQ. Wood ash significantly increased K concentrations (from 17 mg/L to 650 mg/L) in the soil solution, along with Ca, Mg, P, and Mo, while reducing Ni, Mn, Zn, and Cd levels. Komatsuna K uptake surged from 123 mg/kg to 559 mg/kg, leading to a 3.31-fold biomass increase. Notably, the Cd concentration in the crops dropped significantly from 0.709 to 0.057 mg/kg, well below the Codex standard of 0.2 mg/kg. Although Cu and Cr concentrations rose in the soil solution, crop uptake remained low due to >99% complexation with fulvic acid, as confirmed by Visual MINTEQ modeling. This study confirms that wood ash is an effective K fertilizer, but emphasizes the need for risk mitigation strategies to ensure safe and sustainable agricultural application. Full article
(This article belongs to the Special Issue Heavy Metal Pollution and Prevention in Agricultural Soils)
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14 pages, 10631 KiB  
Article
3D Printing Assisted Injection Molding of Chemically Plated W-Cu Composite
by Bo Yuan, Wenwxin Liu, Zhen Wang, Zhongkai Li, Xiaofang Pan, Shurong Xu, Shoujing Mao, Ying Wu, Yangyang Li and Jun Liu
Materials 2025, 18(8), 1885; https://doi.org/10.3390/ma18081885 - 21 Apr 2025
Viewed by 629
Abstract
W-Cu composites are widely used in the fields of switch contact materials and electronic packages because of their high hardness, high plasticity, and excellent thermal conductivity, while the traditional W-Cu composite preparation process is often accompanied by problems such as a long production [...] Read more.
W-Cu composites are widely used in the fields of switch contact materials and electronic packages because of their high hardness, high plasticity, and excellent thermal conductivity, while the traditional W-Cu composite preparation process is often accompanied by problems such as a long production cycle, difficulties in the processing of shaped parts, and difficulties in guaranteeing the uniformity. Therefore, this work developed a chemical plating technique to prepare W-20 wt.% Cu composite powder with a core–shell structure and used this powder as a raw material for powder metallurgy to solve the problem of inhomogeneity in the production of W-Cu composite by the conventional solution infiltration method. Moreover, the work also developed a high-temperature-resistant photosensitive resin, which was used as a raw material to prepare injection molds using photocuring to replace traditional steel molds. Compared to steel molds, which take about a month to prepare, 3D printed plastic molds take only a few hours, greatly reducing the production cycle. At the same time, 3D printing also provides the feasibility of the production of shaped parts. The injection molded blanks were degreased and sintered under different sintering conditions. The results show that the resultant chemically plated W-Cu composite powder has a uniform Cu coating on the surface, and the Cu forms a dense and uniform three-dimensional network in the scanning electron microscope images of each subsequent sintered specimen, while the photocuring-prepared molds were used to prepare the W-Cu shaped parts, which greatly shortened the production cycle. This preparation method enables rapid preparation of tungsten–copper composite-shaped parts with good homogeneity. Full article
(This article belongs to the Section Manufacturing Processes and Systems)
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14 pages, 1829 KiB  
Article
Nickel, Cu, Fe, Zn, and Se Accumulation, and the Antioxidant Status of Mushrooms Grown in the Arctic Under Ni/Cu Pollution and in Unpolluted Areas
by Nadezhda Golubkina, Uliana Plotnikova, Andrew Koshevarov, Evgeniya Sosna, Olga Hlebosolova, Natalia Polikarpova, Otilia Cristina Murariu, Alessio Vincenzo Tallarita and Gianluca Caruso
Stresses 2025, 5(2), 25; https://doi.org/10.3390/stresses5020025 - 2 Apr 2025
Viewed by 839
Abstract
Mushrooms play an important role in ecosystem sustainability and are highly valued in medicine and human nutrition. Using AAS and biochemical methods of analysis, the antioxidant status and mineral composition of seven mushroom species (Armillaria mellea, Xeromocus illudens, Leccinum aurantiacum [...] Read more.
Mushrooms play an important role in ecosystem sustainability and are highly valued in medicine and human nutrition. Using AAS and biochemical methods of analysis, the antioxidant status and mineral composition of seven mushroom species (Armillaria mellea, Xeromocus illudens, Leccinum aurantiacum, Leccinum scrabum, Lactarium pubescens, Rusula vesca, and Lycoperpon molle Pers.) gathered near the Pechenganikel smelting plant in the Pasvik Nature Reserve of the Murmansk region were evaluated. The concentrations of Ni and Cu in the fruiting bodies of mushrooms were in the ranges of 0.43–39.7 and 7.9–45.9 mg kg−1 d.w., respectively. An unusually high biological concentration factor (BCF) for Ni, Cu, and Zn levels in mushrooms grown in soils with a low amount of these elements indicates the low suitability of the mentioned parameter for mushroom characteristics in territories with an uneven distribution of elements in soil. On the other hand, selenium (Se) showed high BCF levels, exceeding 1, for all mushrooms tested, with the highest values associated with L. saccatum (5.17) and the lowest values with A. mellea (1.36). A significant excess (3.4) of the Recommended Daily Allowance (RDA) level per 30 g of dry mushrooms was recorded for Ni in Russula vesca gathered 6 km from the Ni/Cu smelting plant, and 1.3 excess of the RDA was recorded in L. scrabum grown in the vicinity of the Shuonyoka waterfall. No RDA excess was revealed for Cu. Positive correlations between Se, polyphenol content, and total antioxidant activity (AOA) (r = 0.915–0.926; p < 0.001) and a negative correlation between Cu–Se and Cu–AOA in Leccinum species indicate the important role of antioxidant defense and Se, particularly in Arctic mushroom growth and survival, providing a specific protection of mushrooms against Cu toxicity. Full article
(This article belongs to the Collection Feature Papers in Plant and Photoautotrophic Stresses)
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18 pages, 18008 KiB  
Article
Insights into the Electrochemical Synthesis and Supercapacitive Behaviour of 3D Copper Oxide-Based Nanostructures
by Gintautas Jonkus, Ramunas Levinas, Natalia Tsyntsaru and Henrikas Cesiulis
Solids 2025, 6(2), 15; https://doi.org/10.3390/solids6020015 - 1 Apr 2025
Viewed by 1720
Abstract
In this study, nanostructured copper oxide-based films with crystallite size below 10 nm were electrochemically synthesized on copper foil and foam electrodes and investigated for their supercapacitive behaviour. The synthesis was carried out via cyclic voltammetry (CV) for up to 1000 cycles in [...] Read more.
In this study, nanostructured copper oxide-based films with crystallite size below 10 nm were electrochemically synthesized on copper foil and foam electrodes and investigated for their supercapacitive behaviour. The synthesis was carried out via cyclic voltammetry (CV) for up to 1000 cycles in an alkaline electrolyte. By tuning the upper vertex potential (−0.3 V to 0.65 V vs. Ag/AgCl), both phase composition (Cu2O, Cu(OH)2, CuO) and morphology (grains, nanoneedles, nanoplatelets) were precisely controlled, demonstrating the versatility of this approach. The kinetics of oxide/hydroxide film formation on foil and foam electrodes were analysed based on EIS data that were interpreted in the frame of equivalent electric circuits and their changes with potential. The capacitive properties of the synthesized films were evaluated using CV in the potential range of 0 V–0.65 V, and the optimized CuO film synthesized on Cu foam exhibited a high specific capacitance of 1380 mF cm⁻2. An energy density of 0.061 mWh cm−2 and power density of 1.28 mW cm−2 were obtained at 10 mA cm−2 discharge current. Charge–discharge cycling at 100 mV s−1 for 1000 cycles indicated an initial capacitance increase followed by stable retention, highlighting the structural integrity and electrochemical stability of the films obtained on 3D foam. These findings provide valuable insights into the controlled electrochemical synthesis of copper oxide nanostructures and their potential for high-performance capacitor applications. Full article
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25 pages, 1707 KiB  
Article
The Genistein Supply and Elemental Composition of Rat Kidneys in an Induced Breast Cancer Model
by Dorota Skrajnowska, Arkadiusz Szterk, Karol Ofiara, Paweł Kowalczyk and Barbara Bobrowska-Korczak
Nutrients 2025, 17(7), 1184; https://doi.org/10.3390/nu17071184 - 28 Mar 2025
Viewed by 727
Abstract
Background: Many natural phytochemicals support the work of the kidneys. The health effects of genistein have been confirmed in many kidney diseases (inflammation and acute kidney injury, cancer or menopausal or senile changes). Genistein through various mechanisms can affect kidney conditions. Objectives: The [...] Read more.
Background: Many natural phytochemicals support the work of the kidneys. The health effects of genistein have been confirmed in many kidney diseases (inflammation and acute kidney injury, cancer or menopausal or senile changes). Genistein through various mechanisms can affect kidney conditions. Objectives: The purpose of this work was to analyze the supply of various forms of genistein at a low dose (0.2 mg/kg b.w.) on the renal mineral composition of rats under conditions of mammary gland tumorigenesis (induced with DMBA). Methods: Sprague rats at the age of 40 days were divided into four research groups, i.e., a control group receiving only standard feed and four groups receiving feed supplemented with genistein in the form of nanoparticles (0.1 mg/mL, i.e., 0.2 mg/kg.i.d.) (size: 92 ± 41 nm), genistein in microparticle form (0.1 mg/mL, i.e., 0.2 mg/kg.i.d.) (size: 587 ± 83 nm) and genistein in macroparticle form (normal, classical) (0.1 mg/mL, i.e., 0.2 mg/kg.i.d.). Mammary gland cancer was induced using DMBA (7,12-dimethyl-1,2-benz(a)anthracene). The experiment lasted 100 days. The concentrations of Ca, Zn, Fe, Cu, As, Se, Rb, Sr, Mo, B, and Mn were measured using the ICP-MS method, while the levels of K, Mg, and Na were measured using the FAAS method. Results: It was shown that, depending on the degree of miniaturization of genistein, its administration affected changes in kidney mineral composition, primarily resulting in a strongly reduced calcium content in the group of rats receiving nanogenistein. We found a negative impact of nanogenistein administration on the amount of calcium and iron, indicating an increased distribution or excretion of these elements from the body, as well as an increase in the number of elements, especially magnesium, sodium, zinc, boron, and copper concentrations, compared to the non-supplemented group. Conclusions: This study confirms the need for thorough clinical analyses in the future, with regard to the effects of genistein, especially its nanoforms on the body. Full article
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