Search Results (106)

Based on the experience gained worldwide from potential solutions to the fouling problem of fisheries and aquaculture infrastructure, we attempted to design, construct and test the antifouling efficiency of a new hybrid filament created from non-laminated copper wire braided with synthetic fibers made of Dyneema. The design involved the creation of a hybrid twine substituting a percentage of the synthetic fibers with 0.1–0.15 mm diameter copper wire at 5%, 10%, 20% and 40% levels. There is limited information in the international literature for comparison with our results, since there has never been any attempt to create such a hybrid net. The results showed that for the 6 mm mesh, the maximum openness obtained after the 8-month experimental period was 8.72%, with Cu wire substitution at 35%. For the 12 mm mesh, these values were 27.07% at 26%, and for the 20 mm mesh, they were 33.68% at 28%. A conservative average independent from mesh size to achieve optimum openness in the long term is 30 ± 4.73% Cu wire substitution. In addition, we found that both the mesh size (mm) and the copper substitution percentage affected the fouling process during the experimental period, which lasted 8 months. Full article

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

This study signifies the development and characterization of a composite material with a metallic matrix of aluminum reinforced with a steel mesh, utilizing centrifugal casting technology. An evaluation was conducted to ascertain the influence of the formulation process and the presence of the insert on the mechanical behavior with regard to tensile strength. The aluminum matrix was obtained from commercial and scrap alloys, elaborated by advanced methods of degassing and chemical modification. Meanwhile, the steel mesh reinforcement was cleaned, copper plated, and preheated to optimize wetting and, consequently, adhesion. The structural characterization was performed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy analyses (EDX), which highlighted a well-defined interface and uniform copper distribution. The composite was produced by means of horizontal-axis centrifugal casting in a fiberglass mold, followed by cold rolling to obtain flat specimens. A total of eight tensile specimens were examined, with measured ultimate tensile strengths ranging from 78.5 to 119.8 (MPa). A thorough examination of the fractured specimens revealed a brittle fracture mechanism, devoid of substantial plastic deformation. The onset of failures was frequently observed at the interface between the aluminum matrix and the steel mesh. The use of SEM and EDX investigations led to the confirmation of the uniformity of the copper coating and the absence of significant porosity or interfacial defects. A bimodal distribution of tensile strength values was observed, a phenomenon that is likely attributable to variations in mesh positioning and local differences in solidification. A correlation was established between the experimental results and an analytical polynomial model, thereby confirming a reasonable fit. In sum, the present study provides a substantial foundation for the development of metal matrix composites with enhanced performance, specifically designed for challenging structural applications. This method also demonstrates potential for recycling aluminum scrap into high-performance composites with controlled microstructure and mechanical integrity. Full article

As an innovative plant protection method in precision agriculture, electrostatic spray technology can increase the droplet coverage area by over 30% coMpared to conventional spraying. This technology not only achieves higher droplet deposition density and coverage but also enables water and pesticide savings while reducing environmental pollution. This study, combining theoretical analysis with experimental validation, reveals the critical role of electrode material selection in induction-based electrostatic spray systems. Theoretical analysis indicates that the Fermi level and work function of electrode materials fundamentally determine charge transfer efficiency, while corrosion resistance emerges as a key parameter affecting system durability. To elucidate the effects of different electrode materials on droplet charging, a coMparative study was conducted on nickel, copper, and brass electrodes in both pristine and moderately corroded states based on the corrosion classification standard, using a targeted mesh-based charge-to-mass measurement device. The results demonstrated that the nickel electrode achieved a peak charge-to-mass ratio of 1.92 mC/kg at 10 kV, which was 8.5% and 11.6% higher than copper (1.77 mC/kg) and brass (1.72 mC/kg), respectively. After corrosion, nickel exhibited the smallest reduction in the charge-to-mass ratio (19.2%), significantly outperforming copper (40.2%) and brass (21.6%). Droplet size analysis using a Malvern Panalytical Spraytec spray particle analyzer (measurement range: 0.1–2000 µm) further confirmed the atomization advantages of nickel electrodes. The volume median diameter (Dv50) of droplets produced by nickel was 4.2–8 μm and 6.8–12.3 um smaller than those from copper and brass electrodes, respectively. After corrosion, nickel showed a smaller increase in droplet size spectrum inhomogeneity (24.5%), which was lower than copper (30.4%) and brass (25.8%), indicating superior droplet uniformity. By establishing a multi-factor predictive model for spray droplet size after electrode corrosion, this study quantifies the correlation between electrode characteristics and spray performance metrics. It provides a theoretical basis for designing weather-resistant electrostatic spray systems suitable for agricultural pesticide application scenarios involving prolonged exposure to corrosive chemicals. This work offers significant technical support for sustainable crop protection strategies. Full article

The propulsion system is a critical component of medium–low-speed maglev trains and the single-sided linear induction motor (SLIM) has been adopted to generate thrust. However, the SLIM operates periodically in maglev trains. The temperature of the secondary plate of the SLIM rises significantly due to eddy currents when the train enters and leaves the station, where large slip occurs. Subsequently, the temperature decreases through natural cooling during the shift interval time. This periodic operating condition is rarely addressed in the existing literature and warrants attention, as the temperature accumulates over successive periods, potentially resulting in thermal damage and thrust variation. Furthermore, the conductivity of plate varies significantly in the process, which affects the losses and thrust, requiring a coupled analysis. To investigate the temperature variation patterns, this paper proposes a coupled model integrating the lumped parameter thermal network (LPTN) and the equivalent circuit (EC) of the SLIM. Given the unique structure of the F-shaped rail, the LPTN mesh is well designed to account for the skin effect. Three experiments and a finite element method (FEM)-based analysis were conducted to validate the proposed model. Finally, optimizations were performed with respect to different shift interval time, plate materials, and carriage numbers. The impact of temperature on thrust is also discussed. The results indicate that the minimum shift interval time and maximum carriage number are 70.7 s and 9, respectively, with thrust increasing by 22.0% and 22.0%. Furthermore, the use of copper as the plate material can reduce the maximum temperature by 22.01% while decreasing propulsion thrust by 26.1%. Full article

Printed electronics employ established printing methods to create low-cost, mechanically flexible devices including batteries, supercapacitors, sensors, antennas and RFID tags on plastic, paper and textile substrates. This review focuses on the specific contribution of screen printing to that landscape, examining how ink viscosity, mesh selection and squeegee dynamics govern film uniformity, pattern resolution and ultimately device performance. Recent progress in advanced ink systems is surveyed, highlighting carbon allotropes (graphene, carbon nano-onions, carbon nanotubes, graphite), silver and copper nanostructures, MXene and functional oxides that collectively enhance mechanical robustness, electrical conductivity and radio-frequency behavior. Parallel improvements in substrate engineering such as polyimide, PET, TPU, cellulose and elastomers demonstrate the technique’s capacity to accommodate complex geometries for wearable, medical and industrial applications while supporting environmentally responsible material choices such as water-borne binders and bio-based solvents. By mapping two decades of developments across energy-storage layers and functional electronics, the article identifies the key process elements, recurring challenges and emerging sustainable practices that will guide future optimization of screen-printing materials and protocols for high-performance, customizable and eco-friendly flexible devices. Full article

With the proliferation of flexible electronics, the advancement of mechanically compliant thermal management systems, notably flexible heat pipes, is imperative to address evolving demands for adaptive thermal regulation in deformable device architectures. The wicks of heat pipes commonly utilize porous copper. In this study, three types of porous copper materials were fabricated: sintered pure copper powder, sintered copper powder with a copper mesh (as a reinforcing network), and sintered copper powder with NaCl (as a pore-forming agent). Their pore structure characteristics, tensile, and compressive mechanical properties were systematically investigated. Results demonstrated that incorporating NaCl into copper powder significantly increased porosity and enlarged pore size, thereby enhancing permeability. For instance, compared to sintered pure copper powder, the addition of NaCl increased the average pore diameter from 0.31 μm to 2.44 μm and improved permeability from 1.908 × 10⁻¹⁴ m² to 2.832 × 10⁻¹² m², effectively reducing fluid flow resistance. The introduction of copper mesh notably improved mechanical performance: under a sintering temperature of 900 °C, tensile strength increased from 121.6 MPa to 132.2 MPa, and compressive strength rose from 443.5 MPa to 458.4 MPa. However, NaCl-added porous copper exhibited a drastic decline in tensile strength. Consequently, NaCl-modified porous copper is unsuitable for flexible wick applications, whereas copper mesh-reinforced porous copper shows potential as a flexible wick, though further investigation is required to enhance its permeability mechanisms. Full article

This paper presents the design and implementation of a compact, high-isolation, optically transparent 2 × 2 MIMO antenna array. Optical transparency is achieved using a copper-based metal mesh material, which serves as both the radiating element and the ground plane, ensuring high radiation efficiency and minimal visual impact. The array consists of four monopole antennas, and mutual coupling is effectively suppressed through the integration of shorting decoupling branches and a common-ground structure. These techniques address both adjacent and diagonal (non-adjacent) coupling. A prototype was fabricated and experimentally validated. The experimental results demonstrate that the proposed antenna array achieves 20 dB isolation, 3.56 dB antenna gain, and 76% efficiency. Full article

This study aims to determine the effect of adding copper powder with different mesh sizes on the welding point, as well as the resulting tensile strength, micro photo and hardness. The raw material of this research is aluminum type 1100. The tests included tensile strength tests (ASME QW-4629 standard), micro photo tests with a metallographic microscope, and Vickers tests (AWS D8.9-97 standard). The results of the tensile strength test rank mesh 40 (556.38), mesh 50 (739.13) and mesh 60 (1316.10) in descending order of tensile strength. The highest value of hardness is in the fusion zone (nugget). The last heat affected zone is in the base metal area and the order of hardness is, in descending order, mesh size 60, 50, and lastly, 40. For micro images, all of the results obtained are the same because they use the same material. The widest melted area in the welding area is on the 60 mesh and it decreases proportionally with the larger meshes. Full article

The combination of a liquid piston gas compressor and a solid metal insert can achieve a near-isothermal compression process, which can greatly contribute to improving the system efficiency of a compressed-air energy storage system. To examine the effectiveness of the insert at various pressure levels, compressions were performed in a liquid piston compressor with and without copper wire mesh inserts at three different pressures of 1, 2, and 3 bars. The use of inserts increased isothermal compression efficiencies by 8–10% from the baseline isothermal efficiencies about 83–87%, while the compromised air volume due to the inserts was minor. In addition to the solid insert-based technique analysis, a comparative study with other proven liquid-based heat transfer enhancement techniques, spray injection and aqueous foam, was performed. Not only was a quantitative analysis made comparing the isothermal efficiency values but the pros and cons of each technique’s distinctive working mechanisms were also compared. Full article

Copper foil has been widely adopted as the anode current collector in commercial lithium-ion batteries (LIBs) due to its exceptional electrical conductivity, mechanical flexibility, and low cost. However, the smooth surface of copper foil often leads to active material delamination during cycling, resulting in accelerated capacity degradation. To address this limitation, this study developed a novel composite current collector featuring a high specific surface area and rough porous architecture through a dip-coating method. The fabrication process employs copper mesh as a structural skeleton, integrated with carbon nanotubes (CNTs) and polyvinylidene fluoride (PVDF) as functional fillers. Compared to conventional metallic copper foils, the composite current collector demonstrates superior interfacial wettability, enhanced adhesion strength, and reduced contact resistance. When paired with graphite as the active material, the graphite composite electrode exhibits outstanding cycling stability and rate capability. Specifically, the graphite composite electrode delivers a specific capacity of 297.9 mAh g⁻¹ with 94.3% capacity retention after 200 cycles at 0.5 C, significantly outperforming the graphite–copper foil counterpart (238.3 mAh g⁻¹, 81.2% retention). This work provides an innovative strategy for enhancing battery performance through the rational design of efficient and durable current collectors. Full article

This article compares the antibacterial properties of single-layer (Ag) and two-layer (Ag,Cu) coatings deposited onto a polypropylene mesh (endoprostheses for hernioplasty) in various gaseous environments (argon or nitrogen) via magnetron sputtering. The microstructure and elemental composition of the coatings were studied via SEM and TEM. The antimicrobial activity of sterile samples was investigated using the Staphylococcus aureus strain. To prevent the overheating of the polymer samples during the coating process, it is advisable to carry out pulse processing (the total coating formation time is divided into cycles of switching the magnetron on and off for equal periods). All the samples, with both single- and double-layer coatings, exhibited good antibacterial properties; however, the Cu–Ag coating enhanced the antimicrobial effect, increasing it from 97.00 to 99.97%. The glow-discharge plasma etching of the samples with a double-layer coating led to the mixing of the copper and silver layers and an increase in the surface copper content, though this did not affect the antibacterial properties of the samples. Full article

The mechanical and hydrodynamic characteristics of single-piece nets are key to the design and optimization of offshore aquaculture net cages. A numerical approach for offshore submerged aquaculture net materials based on the Morison equations and finite element is proposed, simulating the hydrodynamic characteristics of single-piece nets under varying parameters such as wire diameter, mesh size, and flow velocity, and simulating the impact of marine organism attachment on nets by modifying the drag coefficient. The simulation results of nets made from materials such as Copper–Zinc Alloy (Cu-Zn), Zinc–Aluminum Alloy (Zn-Al), Semi-Rigid Polyethylene Terephthalate (PET), and Ultra-High Molecular Weight Polyethylene (UHMWPE) are compared, which provides a theoretical basis for optimizing design parameters and selecting materials for nets based on force conditions and hydrodynamic characteristics. The simulation results indicate that the current force on the net is positively correlated with flow velocity; the maximum displacement of the net is also positively correlated with the flow rate. Compared to other materials, the Cu-Zn net is subjected to the greatest water flow force, while the UHMWPE net experiences the greatest displacement; the larger the diameter of the netting twine, the greater the current force on the net; the mesh size is inversely related to the current force on the net. With increasing drag coefficient, both the maximum displacement of the net and the current force experiences increase, and UHMWPE material nets are more sensitive to increases in the drag coefficient, which indicates a greater impact from the attachment of marine organisms. The density and elastic modulus of the netting material affect the rate of increase in force on the net. The research results can provide a basis for further research on material selection and design of deep-sea aquaculture nets. Full article

This article presents the results of experimental studies on the influence of the geometry of high-voltage plasma actuator electrodes on the change in flow in the boundary layer and their influence on the change in the lift coefficient. The plasma actuator used in the described experimental studies has a completely different structure. The experimental model of the plasma actuator uses a large mesh ground electrode and different geometries of the high-voltage electrodes, namely copper solid electrodes and mesh electrodes (the use of mesh electrodes, large GND and HV is a new solution). The plasma actuator was placed directly on the surface of the wing model with the SD 7003 profile. The wing model with the plasma actuator was placed in the wind tunnel. All experimental tests carried out were carried out for various configurations. The DBD plasma actuator was powered by a high-voltage power supply with a voltage range from V_p = 7.5–15 kV. The use of a high-voltage mesh electrode allowed for an increase in the lift coefficient (C_L) for the angle of attack α = 5 degrees and the air flow velocity in the range from V = 5 m/s to 20 m/s, while the use of copper electrodes HV with the plasma actuator turned off and on, were very small (close to zero). The experimental studies were conducted for Reynolds numbers in the range of Re = 87,985–351,939. Full article

After rolling, TP2 copper tubes exhibit defects such as sawtooth marks, cracks, and uneven wall thickness after joint drawing, which severely affects the quality of the finished copper tubes. To study the effect of drawing process parameters on wall thickness uniformity, an ultrasonic detection platform for measuring the wall thickness of rolled copper tubes was constructed to verify the accuracy of the experimental equipment. Using the detected data, a finite element model of drawn copper tubes was established, and numerical simulation studies were conducted to analyze the influence of parameters such as outer die taper angle, drawing speed, and friction coefficient on drawing force, maximum temperature, average wall thickness, and wall thickness uniformity. To address the problem of the large number of finite element model meshes and low solution efficiency, the wall thickness uniformity was predicted using a radial basis function (RBF) neural network, and parameter optimization was performed using the particle swarm optimization (PSO) algorithm. The research results show that the RBF neural network can accurately predict wall thickness uniformity, and using the PSO optimization algorithm, the best parameter combination can reduce the wall thickness uniformity after drawing in finite element simulation. Full article