ABSTRACT Marine microplastic pollution, particularly from polystyrene, poses serious risks to ecosystems and human health. Traditional detection methods, though sensitive, are often costly and complex, which restricts their application in large-scale marine monitoring. This study presents a low-cost electrochemical detection – filtration strategy using electrospun nanofiber membranes for the rapid identification and removal of microplastics in seawater. A functional membrane composed of PVDF, chitosan, and SiO₂ is fabricated via electrospinning, offering high porosity, uniform structure, and self-cleaning properties. By comparing the current before and after filtration, a correlation between current response (ΔI) and microplastic concentration is established, enabling semi-quantitative detection. The membrane effectively filters 10–50 μm polystyrene microplastics with a theoretical efficiency above 90%, while maintaining hydrophobicity under dynamic seawater conditions. This approach provides a practical, minimally instrumented, portable solution for marine microplastic monitoring and offers theoretical support for the development of efficient sensing materials.

ABSTRACT For improving accuracy and aspect ratio of micro-rods, a wire electrical discharge grinding method based on controllable slit (CS-WEDG) was proposed. Wire electrode included angle β effectively improves material removal accuracy of micro-rods and makes removal resolution smaller than the feed resolution of motion axis. In addition, the CS-WEDG method has the advantage of being insensitive to the machine tool positioning accuracy. Through experiments, it is found that the wire electrode fluctuation amplitude has a positive correlation with the tension fluctuation rate. The adverse influence of wire electrode fluctuation can be avoided by keeping the wire electrode stationary during finishing. The micro-rod is affected by wire electrode wear (WEW) when fed along the rectangular wave path, resulting in an olive-shaped outline. By optimizing feed path, the inverted triangle feed strategy can compensate for wire electrode wear, which can control the diameter error of micro-rods within ± 1 μm. Through the optimization of feed parameters, the high aspect ratio micro-rod can be fabricated, which has a 48 ± 1 μm diameter with a 33.3 aspect ratio.

ABSTRACT This research focuses on the conversion of an ethylene glycol solution – one of the hydrolysis products of PET waste – into reduced graphene oxide (rGO), a high-value product, through thermal processes. According to characterization methods, FT-IR spectrum analysis revealed aromatic C = C, C – H, and – COOH bonds in the material. Raman spectroscopy indicated G and D peaks related to the rGO structure. EDX elemental analysis showed 77.33% carbon, 20.91% oxygen, and 1.77% sulfur. SEM images exhibited thick, rough layers and bud-like structures. The C1s XPS spectrum of rGO showed oxygen-free ring C (284.1 eV) and oxidized carbon (C – O at 285.4 eV, C = O, O – C = O at 288.6 eV). This study successfully produced reduced graphene oxide using a simple, rapid, one-step method, creating new opportunities for recycling PET, a significant plastic waste. Recycling PET waste from plastic bottles can provide economic and environmental benefits, making high-value products from plastic recycling more attractive.

ABSTRACT This work aims to study the processing performance and optimize the CNC (Computer Numerical Control) turning process to reduce the environmental impact of CNC machining operations while maintaining efficiency and productivity. Experiments are conducted using an I-optimum design that takes into account four factors: spindle speed (x1), depth of cut (x2), feed rate (x3), and environment (x4) (wet and dry). The desirability function approach is used to evaluate the effects of these factors and optimize material removal rate (y1), surface roughness (y2), energy consumption (y3), and machining cost (y4). The optimal setting obtained is x1(250 rpm), x2 (1.5 mm), x3 (0.20 mm/min), and x4 (dry condition) and optimized responses are y1 (MRR) as 284.42 mm3/min, y2 (Ra) as 1.07 µm, y3 (energy consumption) as 1769.44 kJ, and y4 (total machining cost) as Rs. 80.47, respectively. The findings of the study are validated through confirmatory trials. By implementing the results of the study, manufacturers can reduce the environmental footprint of machining operations and thus contribute to the overall goal of achieving a more sustainable manufacturing industry.

ABSTRACT The tool pin design of the Friction Stir Welding (FSW) tool is important for the generation of heat, plasticization and flow of material. The stirring of the tool pin between the tool-workpiece material has a considerable impact on the evolution of grain size, the formation of weld defects and the overall strength of the weld joint. This study presents a detailed examination of various tool pin geometries such as cylindrical, cylindrical threaded, tapered cylindrical, taper threaded cylindrical, tri-flute and polygonal tools and their implications on mechanical properties and microstructural evolution for producing defect-free joints. The rationale behind this study is to consolidate scattered research for AA6061-T651 materials and to identify the impact of different tool pin geometries in relation with process variables. Also, need for optimization and standardization of various process variables relative to the tool pin geometry to achieve a high-strength joint is discussed to address various industrial applications. Various research gaps specifically in numerical modeling, process control optimization, effect of pulsating action in polygonal tools, plunge force monitoring, heat input characterization, etc are identified that will further promote FSW developments, ensuring their increased usage with enhanced efficiency, reliability and sustainability.

ABSTRACT Industries are currently focused on reducing cutting zone temperatures and improving machining performance while minimizing coolant use through eco-friendly methods. Tool surface texturing combined with Minimum Quantity Lubrication (MQL) is emerging as an effective anti-adhesion technique to enhance tool life and machining performance. In this study, a novel textured tool was fabricated using a laser texturing machine, and its performance was evaluated. The performance of an untextured tool (UT) was compared to that of a circular pit hole textured tool (CPT) when the cutting of EN24 alloy steel via MQL, with varying cutting conditions. The cutting temperature (Tm), surface roughness (Ra), rake wear (Rw), flank wear (Vb) and chip morphology were investigated under modified cutting inserts. The test results, revealed that the Tm, Rw, Ra, and Vb of the CPT tools were reduced by up to 11.35%, 17.59%, 7.47%, and 4.47%, respectively, compared to the UT. The experimental findings suggest that a slight mitigation in the cutting region temperature results in enhanced machining performance.

ABSTRACT In the current scenario, the demand for eco-friendly manufacturing techniques has been raising due to stringent rules on utilization of chemical coolants. Minimum Quantity Lubrication (MQL) cooling and surface textured tool techniques support eco-friendliness. However, the machining performance of textured tools under MQL technique significantly depends on geometry of the textured design and its coolant storage capabilities during machining operation. In this context, in the current work, new dual textured design cutting tools were fabricated and assessed for its performance in turning of AISI304 material under MQL conditions. Experiments were conducted using orthogonal array design with both textured and untextured tools. Results indicated that textured tools demonstrated superior turning performance in terms of cutting temperature (T), tool rake wear (Vr), tool flank wear (Vb), and surface roughness (Ra), with maximum reductions of 48%, 24%, 45%, and 28%, respectively, than non-textured tools. Further, higher BUE and edge chipping out mechanisms were pragmatic in conventional tools. Furthermore, it was revealed that derivative cutting mechanism and effective cooling are accountable for paramount results in textured tools. The proposed combination of machining technique in the current study cares about environmental cleanness along with process improvement and contributes to a few of the sustainable development goals.

ABSTRACT A novel methodology combining WAAM with post-deposition ultrasonic impact treatment (UIT) was developed to address the challenges of excessive grain coarsening and compromised mechanical characteristics in ultrahigh-strength steel (UHSS) builds subjected to intensive thermal cycles. The research found that compared to the directly deposited samples, the grain refinement at the top of the ultrasonic impact-treated samples improved by 12.5%, while the refinement in the middle section increased by 15%. Quantitative analysis revealed differential strain localization patterns, with the surface-adjacent region demonstrating 40.63% KAM enhancement compared to 9.4% improvement in central bulk material. UIT-assisted WAAM processing significantly reduced anisotropy, where the horizontally oriented tensile strength reached 185.94 MPa, representing an 18.6% increment over conventional high-heat-input deposition techniques. This strengthening mechanism originates from the effects of UIT, which simultaneously induces grain refinement, elevates dislocation configuration complexity, and facilitates homogeneous Ni₃Ti intermetallic precipitation throughout the matrix. Therefore, by introducing ultrasonic impact treatment, the microstructural morphology of the deposited samples is improved, and their mechanical properties are enhanced, all while maintaining high deposition efficiency.

ABSTRACT Ultra-thin SUS304 stainless steel, a high-end raw material, is widely applied in various high-tech fields. For rolling processing, it is difficult to reduce the thickness of SUS304 stainless with the smallest possible rolling thickness. Herein, a novel electrochemical machining (ECM) method called scanning electrochemical thinning is developed for the subsequent thinning process through the straight reciprocating motion of a cathode. First, the distributions of the electrolyte flow rate and the density of electric current during the machining process are explored utilizing a dynamic simulation. Next, the influence of processing conditions on the ECM performance is investigated using a specially designed experimental system with an integrated cathode. Finally, various machining strategies for an SUS304 strip are compared, and the repeated feeding of integrated cathode with a low material removal rate shows the correct thickness reduction and low surface roughness. Above results verify the feasibility of the proposed approach.

ABSTRACT Optimization of laser machining parameters is crucial for cutting high-precision and high-quality stent profiles on nickel-titanium-cobalt shape memory alloys (NiTiCo SMA). Performance and reliability directly influence the key parameters, namely kerf width (KW), heat-affected zone (HAZ), and surface roughness (Ra). To align the intricate patterns of the stent, KW is modified for precision and accuracy. By fine-tuning the laser parameters, the desired material removal rate can be achieved without compromising the structural integrity of the alloy. Ra impacts the stent performance significantly by influencing blood flow and tissue response. Lower Ra values are preferred, necessitating precise control of laser parameters to achieve smooth surfaces. HAZ must be minimized to prevent thermal damage, that could alter the mechanical properties and shape memory effect (SME). The DEAR (Data Envelopment Analysis-based Ranking) method systematically optimizes the input parameters. Through iterative testing and process adjustments using the DEAR methodology, the optimal combination of KW, Ra, and HAZ can be determined, ensuring that the laser machining process produces stents with superior quality, enhanced biocompatibility, and reliable performance for medical applications.