Search Results (341)

The most prevalent growth of Candida cells is based on biofilm development, which causes the intensification of antifungal resistance against a large range of chemicals. Nanoparticles can be synthesized using green methods via various biological extracts and reducing agents to control Candida biofilms. This study aims to compare copper oxide nanoparticles (CuONPs) synthesized through chemical methods and those synthesized using Cinnamomum verum-based green methods against Candida infections and their biofilms isolated from Iraqi patients, with the potential to improve treatment outcomes. The physical and chemical properties of these nanoparticles were characterized using Fourier-transform infrared spectroscopy (FT-IR,) scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). Four strains of Candida were isolated and characterized from Iraqi patients in Tikrit Hospital and selected based on their ability to form biofilm on polystyrene microplates. The activity of green-synthesized CuONPs using cinnamon extract was compared with both undoped and doped (Fe, Sn) chemically synthesized CuONPs. Four pathogenic Candida strains (Candida glabrata, Candida lusitaniae, Candida albicans, and Candida tropicalis) were isolated from Iraqi patients, demonstrating high biofilm formation capabilities. Chemically and green-synthesized CuONPs from Cinnamomum verum showed comparable significant antiplanktonic and antibiofilm activities against all strains. Doped CuONPs with iron or tin demonstrated lower minimum inhibitory concentration (MIC) values, indicating stronger antibacterial activity, but exhibited weaker anti-adhesive properties compared to other nanoparticles. The antiadhesive activity revealed that C. albicans strain seems to produce the most resistant biofilms while C. glabrata strain seems to be more resistant towards the doped CuONPs. Moreover, C. tropicalis was the most sensitive to all the CuONPs. Remarkably, at a concentration of 100 µg/mL, all CuONPs were effective in eradicating preformed biofilms by 47–66%. The findings suggest that CuONPs could be effective in controlling biofilm formation by Candida species resistant to treatment in healthcare settings. Full article

A Cu-11.85Al-3.2Mn-0.1Ti shape memory alloy (SMA) with excellent superelasticity and shape memory effect was successfully fabricated via selective laser melting (SLM). Increasing the energy density enhanced grain refinement, achieving a 90% refinement rate compared to cast alloy, with an average width of ~0.15 µm. Refined martensite lowered transformation temperatures and increased thermal hysteresis. Nanoscale Cu₂TiAl phases precipitated densely within the matrix, forming a dual strengthening network combining precipitation hardening and dislocation hardening. This mechanism yielded a room-temperature tensile strength of 829.07 MPa, with 6.38% fracture strain. At 200 °C, strength increased to 883.68 MPa, with 12.26% strain. The maximum tensile strength represents a nearly 30% improvement on existing laser-melted quaternary Cu-based SMAs. Full article

Prussian blue analogs (PBAs) are widely recognized as promising candidates for aqueous zinc-ion batteries (AZIBs) due to their stable three-dimensional framework structure. However, their further development is limited by their low specific capacity and unsatisfactory cycling performance, primarily caused by phase transformation during charge–discharge cycles. Herein, we employed a high-entropy strategy to introduce five different metal elements (Fe, Co, Ni, Mn, and Cu) into the nitrogen–coordinated M_a sites of PBAs, forming a high-entropy Prussian blue analog (HEPBA). By leveraging the cocktail effect of the high-entropy strategy, the phase transformation in the HEPBA was significantly suppressed. Consequently, the HEPBA as an AZIB cathode delivered a high reversible specific capacity of 132.1 mAh g⁻¹ at 0.1 A g⁻¹, and showed exceptional cycling stability with 84.7% capacity retention after 600 cycles at 0.5 A g⁻¹. This work provides innovative insights into the rational design of advanced cathode materials for AZIBs. Full article

The addition of beryllium (Be) to Al–Cu alloys enhances their mechanical properties and corrosion resistance. This study aims to investigate the effects of solidification cooling rates and the addition of Be on the microstructural refinement and corrosion behavior of an Al–5wt.%Cu–1wt.%Si–0.5wt.%Be alloy. Radial solidification under unsteady-state conditions was performed using a stepped brass mold, producing four distinct cooling rates. An experimental growth law, λ₂ = 26${\dot{\mathrm{T}}}^{-1/3}$, was established, confirming the influence of Be and the cooling rate on dendritic size reduction. The final microstructure was characterized by an α-Al dendritic matrix with eutectic compounds (α-Al + θ-Al₂Cu + Si + Fe-rich phase) confined to the interdendritic regions. No Be-containing intermetallic phases were detected, and beryllium remained homogeneously distributed within the eutectic. Notably, Be addition promoted a morphological transformation of the Fe-rich phases from angular or acicular forms into a Chinese-script-like structure, which is associated with reduced local stress concentrations. Tensile tests revealed an ultimate tensile strength of 248.8 ± 11.2 MPa and elongation of approximately 6.4 ± 0.5%, indicating a favorable balance between strength and ductility. Corrosion resistance assessment by EIS and polarization tests in a 0.06 M NaCl solution showed a corrosion rate of 28.9 µm·year⁻¹ and an Epit of −645 mV for the Be-containing alloy, which are lower than those measured for the reference Al–Cu and Al–Cu–Si alloys. Full article

The CASTRIP process is an innovative method for producing flat rolled low-carbon and low-alloy steel at very thin thicknesses. By casting steel close to its final dimensions, enormous savings in time and energy can be realized. In this paper, an ultra-high-strength low-alloy corrosion-resistant steel was produced through the CASTRIP process. Microstructure and properties were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser confocal microscopy (LSCM), electron backscattered diffraction (EBSD), and tensile testing. The results show that the microstructure is mainly composed of polygonal ferrite, bainite ferrite, and acicular ferrite. The bainite ferrite forms parallel lath bundles nucleating at austenite grain boundaries, propagating perpendicularly into the parent grains. The acicular ferrite exhibits a cross-interlocked morphology preferentially nucleating at oxide/sulfide inclusions. Microstructural characterization confirms that the phase transformation of acicular ferrite and bainite ferrite introduces high-density dislocations, identified as the primary strengthening mechanism. Under the CASTRIP process, corrosion-resistant elements such as Cu, P, Sb, and Nb are completely dissolved in the matrix without grain boundary segregation, thereby contributing to solid solution strengthening. Full article

This study fabricated a C/C-CuNi composite using the hydrothermal co-deposition method and investigated its friction and wear behavior as well as the underlying mechanisms after being subjected to arc discharge ablation. The results indicate that the graphitization degree of the material matrix was significantly enhanced after arc discharge ablation, accompanied by a transformation in the carbon microstructure. Carbon nanotubes and graphene structures were generated in the arc ablation zone. Under low arc discharge density, limited pits and open pores are formed on the material surface, with the generated graphene structures effectively reducing friction. Specifically, CN-5 exhibited a stable friction coefficient, a wear rate of 5.2 mg/km, and partial self-repair capability. In contrast, CN-10, under high arc discharge density, suffered from structural collapse, matrix-fiber debonding, and extensive open pores, leading to increased surface roughness. The combined effects of frictional heat and Joule heating elevated the wear surface temperature, triggering matrix oxidation and a sharp rise in wear rate to 14.7 mg/km. The wear mechanisms of C/C-CuNi composites under continuous arc conditions involve arc erosion wear, oxidative wear, abrasive wear, and adhesive wear. Full article

This study critically examines the early Cretaceous carbonate-hosted Zn-Pb (±Ba±Cu) deposits of the Malayer-Esfahan (MEMB) and Yazd-Anarak (YAMB) metallogenic belts in Iran, which have been inaccurately classified as Mississippi Valley type (MVT) deposits by Nejadhadad et al. (2025). Our findings reveal significant differences in mineralogy, fluid inclusion characteristics, and geochemical signatures compared to typical MVT deposits. These deposits are more akin to Irish-type Zn-Pb mineralization and formed in extensional and passive margin environments around the Nain–Baft back-arc basin. The normal faults in this back-arc rift can transform significantly during inversion and compressional tectonics, reactivating to behave as reverse faults and leading to new geological structures and landscapes. Our study highlights barite replacement as a crucial factor in forming sediment-hosted Zn-Pb (±Ba±Cu) and barite-sulfide deposits. Based on textural evidence, fluid inclusion data, and sulfur isotope analyses, we propose that barite plays a fundamental role in controlling subsequent Zn-Pb (±Ba±Cu) mineralization by serving as both a favorable host and a significant sulfur source. Furthermore, diagenetic barite may act as a precursor to diverse types of sediment-hosted Zn-Pb (±Ba±Cu) mineralization, refining genetic models for these deposits. Sulfur isotope analyses of Irish-type deposits show a broad δ³⁴S range (−28‰ to +5‰), indicative of bacterial sulfate reduction (BSR). Nevertheless, more positive δ³⁴S values (+1‰ to +36‰) and textural evidence in shale-hosted massive sulfide (SHMS) deposits suggest a greater role for thermochemical sulfate reduction (TSR) in sulfide mineralization. Full article

The gas adsorption and sensing properties of a transition metal oxide (TMO)-ZnO heterojunction-based sensor for H₂, CO, and C₂H₄ are analyzed. It is found that CuO, Ag₂O, and Cu₂O stably composite onto the surface of ZnO by forming heterojunctions, which helps to improve the gas sensing and selectivity of the sensor. The adsorption results show that CuO-ZnO shows physical adsorption for H₂ and good gas sensing performance for CO and C₂H₄, while Ag₂O-ZnO and Cu₂O-ZnO have significant responses for H₂, CO, and C₂H₄. In addition, the introduction of the TMO-ZnO heterojunction structure can effectively avoid the sensor poisoning phenomenon, as the gas adsorption process does not destroy the original geometric configuration of the heterojunction. This study lays a theoretical foundation for preparing TMO-ZnO heterojunction-based sensors for transformer defect detection and energy efficiency analysis. Full article

Cu-Fe in situ composites often face challenges in achieving high strength during cold rolling due to the inefficient transformation of partial Fe phases into fibrous structures. To uncover the underlying mechanisms, this study systematically investigates the co-deformation behavior of Cu and Fe phases in a Cu-10Fe alloy subjected to cold rolling at various strains. Through microstructure characterization, texture analysis, and mechanical property evaluation, we reveal that the Cu matrix initially accommodates most applied strain (ε_vm < 1.0), forming shear bands, while Fe phases (dendrites and spherical particles) exhibit negligible deformation. At intermediate strains (1.0 < ε_vm < 4.0), Fe phases begin to deform: dendrites elongate along the rolling direction, and spherical particles evolve into tadpole-like morphologies under localized shear. Concurrently, dynamic recrystallization occurs near Fe phases in the Cu matrix, generating ultrafine grains. Under high strains (ε_vm > 4.0), Fe dendrites progressively transform into filaments, whereas spherical Fe particles develop long-tailed tadpole-like structures. Texture evolution indicates that Cu develops a typical copper-type rolling texture, while Fe forms α/γ-fiber textures, albeit with sluggish texture development in Fe. The low efficiency of Fe fiber formation is attributed to the insufficient strength of the Cu matrix and the elongation resistance of spherical Fe particles. To optimize rolled Cu-Fe in situ composites, we propose strengthening the Cu matrix (via alloying/precipitation) and suppressing spherical Fe phases through solidification control. This work provides critical insights into enhancing Fe fiber formation in rolled Cu-Fe systems for high-performance applications. Full article

In Chile, copper concentrate production through mineral flotation is increasing while production through hydrometallurgical processes is decreasing due to the depletion of oxidized ores. Using the idle capacity of hydrometallurgy plants for acid pretreatment of sulfate ores before the leaching stage is an attractive alternative; however, a deeper understanding of the process and the products of such treatment is required. In this study, the mineral species formed during acid pretreatment are characterized to identify new mineralogical species. Pretreatment was conducted at 50 °C with 210 kg/t H₂SO₄ over 15 days on a copper concentrate mainly composed of enargite (35.93%). The characterization techniques used were X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and X-ray Photoelectron Spectroscopy (XPS). XRD identified copper sulfate (CuSO₄) formation and the disappearance of chalcocite/digenite (Cu₂S) and bornite (Cu₅FeS₄), indicating their transformation into sulfates. FESEM showed that enargite particles were oxidized, suggesting they did not form copper sulfates. The XPS results confirmed the presence of copper in species such as sulfides and sulfates. The results indicate that chalcocite and bornite transformed into copper sulfates, while chalcopyrite and enargite were only superficially oxidized. The combination of techniques allowed for a detailed identification of mineral transformations during pretreatment. Full article

A chiral gelator (R)-H₆L with multiple carboxyl groups based on a 1,1′-bi-2,2′-naphthol (BINOL) skeleton was prepared, and it could form a supramolecular gel under the induction of water in DMSO/H₂O and DMF/H₂O (1/1, v/v). In the EtOH/H₂O system, the original partial gel transformed into a stable metal–organic gel (MOG), specifically with Cu²⁺ among 20 metal ions. It is proposed that Cu²⁺ coordinates with the carboxyl groups of (R)-H₆L to form a three-dimensional network structure. With the addition of a variety of α-hydroxy acids and amino acids, the Cu²⁺-MOG collapsed with merely 0.06 equivalents of L-tartaric acid (L-TA), while other acids required much larger amounts to achieve the same effect, realizing the visual chemoselective and enantioselective recognition of tartaric acid. Therefore, the chiral gelator (R)-H₆L achieved the tandem visual recognition of Cu²⁺ and chiral tartaric acid by sequence gel formation and collapse, offering valuable insights for visual sensing applications and serving as a promising model for future chiral sensor design. Full article

The traditional hot-dip tinning processes face challenges in controlling excessive copper dissolution and interfacial instability. This study involved designing a dissolution experiment using the hot-dip tin plating process. Through microscopic characterization and dissolution kinetics analysis, it systematically revealed the regulatory mechanism of trace Ni addition (0–0.5 wt.%) on the dissolution behavior and interfacial reaction of copper wire in a tin alloy melt. The experiment showed that Ni atoms formed a (Cu_1−x,Ni_x)₆Sn₅ ternary phase by replacing Cu in the Cu₆Sn₅ lattice, resulting in a transformation of the grain morphology of the IMC layer from equiaxed to fibrous. At the same time, the addition of Ni changed the kinetics of the interfacial reaction, effectively increasing the activation energy from 40.84 kJ/mol in the pure Sn system to 54.21 kJ/mol in the Sn-0.5Ni system, which extended the complete dissolution time of the copper wire at 573 K by three times. Full article

The polyol method under a single pot has successfully produced a coating of CuO, TiO₂, and the combination of CuO/TiO₂ around Ag NWs under sequential addition. The Ag NWs and their coating with a pure metal oxide and a hybrid of metal oxide were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with EDX, X-ray photoelectron spectroscopy (XPS), UV–Visible, photoluminescent (PL) spectroscopy, and cyclic voltammetry (CV). The formation of ultra-thin NWs was also been seen in the presence of the TiO₂ coating. The ultra-thin and co-axial coating of each metal oxide and their hybrid form preserved the SPR of the Ag NWs and demonstrated photon harvesting from the 400–800 nm range. The band gap hybridization was confirmed by CV for the Ag@CuO/TiO₂ design, which made the structure a reliable catalyst. Therefore, the material expresses excellent photocatalytic activities for carcinogenic textile dyes such as turquoise blue (TB), sapphire blue (SB), and methyl orange (MO), with and without the reagent H₂O₂. The hybrid form (i.e., Ag@CuO/TiO₂) exhibited degradation within 6 min in the presence of H₂O₂. Additionally, the material showed antibacterial activities against various bacteria (Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Bacillus pumilus) when assayed using broth media. Therefore, the materials have established degrading and disinfection roles suitable for environmental perspectives. The role of coating with each metal oxide and their hybrid texture further improved the growth of Ag NWs. The preparatory route possibly ensued metal–metal oxide and metal–hybrid metal oxide Schottky junctions, which would expectedly transform it into a diode material for electronic applications. Full article

In this study, we studied the process of recovering copper from mine-leached water at an altitude of 4500 m. The process was ion exchange–esolution–nanofiltration–separation–cyclone electrodeposition. As a result, high-purity copper cathodes were produced. The study demonstrated that the maximum adsorption capacity of ion exchange resin D402 for Cu²⁺ reached 174.6 g/L and the efficiency of Cu²⁺ adsorption and eluent was found to be 97.2% and 94.2%, respectively. The results of Fourier Transform infrared spectroscopy (FTIR) analysis indicated that the resin contains -OH and -NH₂. The lone pair electrons on O and N atoms can form coordination bonds with copper ions to form stable complexes. The results of X-ray photoelectron spectroscopy (XPS) analysis indicated that copper ions were absorbed into the resin. The recovery efficiency of Cu²⁺ throughout the entire process reaches 95.1%, and the purity of the resulting copper cathode reaches 99.997%. This method is distinguished by a straightforward process, minimal environmental impact, optimal operating conditions, high copper recovery efficiency, and a high copper grade. Full article

Developing effective treatment technologies for heavy metal-contaminated biomass is of great environmental significance. This study explores the hydrothermal carbonization (HTC) of biomass contaminated with heavy metals (Cu, Zn, Cd, and Pb), focusing on the migration, transformation, and ecological stability of these metals during the process. Biomass samples were treated under subcritical conditions at varying temperatures (170–260 °C) and reaction times (1–4 h). Results showed that heavy metals were mainly enriched in biochar (>98%), and Cu predominantly transformed into metallic copper (Cu⁰), Zn tended to form stable organometallic complexes or remain in non-volatile forms, Pb coexisted in both metallic and carbonate species, and Cd converted into metallic and oxidized states. The transformation of these metals was influenced by reaction parameters, such as temperature and time, which affected both their immobilization and the structural properties of the prepared hydrochar. The Tessier extraction experiments showed that the unstable state (F1, F2) of heavy metals in hydrochar was obviously reduced from 17.9% to 6.8%, and the heavy metals were significantly stabilized compared with the original biomass. This research highlights the potential of HTC as a dual-purpose technology for biomass conversion and heavy metal remediation, offering insights for stabilizing contaminants and producing environmentally stable biochar products. Full article