Investigation of cleaning mechanisms for particle, metal ion, and organic contaminations in amorphous carbon post-CMP cleaning

Production quality is a key factor determining success in every industrial sector. To achieve these quality standards, PT. XYZ, a manufacturer of battery electric vehicles (BEVs) in Indonesia, implements a smart quality control system across its entire production line, from electrodes to formation. However, the production process involves many stages and has the potential for contamination by foreign particles. This study focuses on the cathode coating stage at PT. XYZ after copper (Cu) particles were found in electrode samples taken from the bobbin, guide roll, and top head areas. Identification was carried out using EA-300 VHX and showed that the Cu particles had characteristics consistent with indications of contamination from machine components. These initial findings were then followed up by the company through a quality audit conducted in October 2025 to determine the source of the problem and assess the actual condition of the process. This study used the SMART approach and Seven Tools to analyze the causes of contamination and formulate applicable improvements. The analysis results showed that contamination was influenced by suboptimal machine conditions, lack of cleanliness SOPs, and limitations of visual inspection in the smart quality control system. The recommended improvements focused on rearranging the coating parameters, strengthening the cleaning SOP, adding a vision camera to the unwinder, and performing regular maintenance on critical components. Through these improvements, it is hoped that the number of defects caused by particle contamination can be reduced to below the process tolerance limit and support continuous improvement in electrode production quality.

The co astal karstic aquifer of Puerto Morelos, Mexico, is under constant environmental stress due to leakage from poorly constructed and managed septic systems and unregulated solid waste disposal sites within and around the town. The presence of the aforementioned pollution sources in the region motivated the implementation of a contaminant transport model and particle tracking analysis, based on results from a previously constructed groundwater flow model of the local aquifer. Simulations of contaminant plumes revealed a high dilution capacity, with chloride concentrations declining to background concentration levels within approximately 300m from the pollution sources (disposal sites and septic systems). This dilution is attributed to the high hydraulic conductivities in the regional aquifer and the presence of a groundwater dome located beneath the urban area. The dome was shown to significantly affect local flow patterns and gradients, as particle tracking analysis indicated longer travel times farther from its center. These findings suggest that the Puerto Morelos aquifer currently exhibits a high potential for contaminant attenuation under current pollution conditions. However, with expected population and tourism growth, improvement in wastewater and solid waste disposal management practices will be paramount to minimize the risk of groundwater contamination, which is the sole source of fresh water for the Puerto Morelos community.

ABSTRACT Harsh working conditions such as high dust, high humidity, and abrasive particle contamination exist underground in coal mines. In such environments, the plunger pair is vulnerable to impacts, and the problem of wear failure is prominent. Taking the RMI Trimax S500 plunger pump as the research object, a plunger with an alumina coating was selected, the type of coating material and spraying process parameters were clarified, and relevant mechanical calculation formulas were derived. Three-dimensional models corresponding to plunger pairs of different structures were established to simulate the stress distribution under typical pump unit operating pressure, and the fatigue life was theoretically calculated using the Archard wear formula. The results show that with the increase of plunger diameter, the stress distribution in the static analysis shows dispersed stress spots; in the dynamic analysis, the maximum stress of the plunger pair shows a continuous climbing trend, while the fatigue life shows a decreasing trend. Theoretical basis and engineering reference is provided to the selection of plunger pairs in high-water-based high-pressure emulsion pumps, and has important engineering significance for improving the overall reliability of the pump body and extending its service life.

Direct and indirect metal contamination of estuarine sediments by boat paint particles.

Preliminary cadaver study of Surgical Humidification (HumiGard™) demonstrating reduced intra-wound particle counts during total hip arthroplasty.

Planetary journal bearings are enablers for wind turbine gearbox torque density and reliability increase due to their compactness and potentially unlimited lifetime. They are designed to withstand the load conditions during wind turbine operation. Despite their general robustness, abnormal events such as particle contamination, strong overload or operation without sufficient oil supply may be harmful to the bearings. In these cases, damage can occur quickly and with little warning time. Such spontaneous failure leads to turbine downtime and cost-intensive repair work on the wind turbine drive train. Thus, reliable load and condition monitoring systems, which allow the detection of critical operating states before damage occurs, would be beneficial. For journal bearings in wind turbine gearboxes, no commercially available monitoring system exists to date. The existing studies on journal bearing condition monitoring are limited to experiments on component test rigs or small gearboxes, and their transferability to full-size systems has yet to be proven. This work presents the results of a system test with an 850 kW wind turbine gearbox equipped with planetary journal bearings and a novel condition monitoring system based on the measurement of surface acoustic waves. First, the journal bearing design, including the sensor setup, is explained. Second, the test campaign layout is presented. The gearbox is tested under load conditions specific to wind turbines, and the condition monitoring signals are examined in detail. An algorithm based on a machine learning model is presented for evaluating the monitoring signals and predicting the friction state of the bearings. Finally, the practical feasibility and quality of the monitoring approach for planetary journal bearings presented in this work is discussed.

Purpose In response to the issue of abnormal reducer operation caused by unreasonable maintenance of coal mine equipment lubrication systems contaminated by coal dust, this study aims to investigate the impact of coal dust on the friction performance of lubricating oil. Design/methodology/approach 200-mesh anthracite particles were selected as contaminants. The effects of particle concentration and load on lubricant friction properties were investigated through four-ball friction tests, scanning electron microscopy, energy-dispersive spectroscopy and X-ray photoelectron spectroscopy analysis. Validation was conducted on a gear test bench, with gear wear observed using an iron content analyzer and a 3D profilometer. Findings The PB value of lubricating oil decreases as the mass fraction of coal particles increases. As the mass fraction of coal particles increases, the lubricating oil’s coefficient of friction and wear scar size first increase then decrease under high-speed light-load conditions; under low-speed heavy-load conditions, they first decrease then increase. At low loads (≤80 kgf), coal particles exacerbate friction; under high loads (>80 kfg), the mending effect of coal particles becomes dominant, thereby reducing wear. Originality/value The study revealed the mechanism by which load affects the contamination of lubricating oil by coal particles. Coal particle contamination is not solely detrimental. Under high loads, its lubricating effect becomes dominant, providing a theoretical basis for optimizing oil change cycles and maintenance schedules in lubrication systems. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2025-0376/

Leveraging water-solid interactions, hydrovoltaic technology converts ambient thermal energy to electricity through ubiquitous water evaporation. While substantial research efforts have focused on improving the electrical output of evaporation-induced electricity generation (EEG), the antifouling capability and long-term durability of such devices in real-world environments remain largely unaddressed. In this study, we designed a Janus dual-layer EEG device in which a top superhydrophobic layer protects a bottom hydrophilic electricity-generating layer. The nanoporous superhydrophobic layer permits water vapor transmission from the underlying evaporative layer while effectively repelling liquid water and various types of foulants. The Janus EEG device achieved an open-circuit voltage of ∼1.1 V and maintained stable performance when exposed to particulate contaminants and intermittent water dripping, whereas the output of a single-layer EEG device ceased due to overwetting of the evaporative layer. Moreover, the superhydrophobic layer functioned as a protective plastron to preserve the structural integrity of the evaporative layer under impact from falling water drops. One-week-long outdoor test confirmed the superior performance of the Janus EEG device over its single-layer counterpart under various weather conditions and fluctuating ambient temperature and humidity. Our work proposes a promising Janus dual-layer design and highlights enhanced antifouling and durability as a key pathway to all-weather hydrovoltaic applications.

Introduction Infection remains a clinically significant problem in orthopaedic surgery, particularly in joint arthroplasty. Current Infection prevention protocols aim to provide an aseptic operating room environment. An intervention to further reduce airborne particles local to the surgical site may be valuable to protect against infection. Surgical Humidification (F&P HumiGard™) is a novel device designed to provide a warm and hydrated wound environment and reduce particles entering the orthopaedic surgical site. This study aimed to evaluate the ability of HumiGard to deflect airborne particles during a dynamic simulation of total hip arthroplasty, involving movement of tools, surgeon's hands, and tissue. Methods A simulated total hip arthroplasty was performed on a human cadaver using the direct anterior approach under laminar downflow conditions. HumiGard was positioned at the surgical site before incision and remained throughout the procedure. Images of the surgical site were taken during the procedure. Airborne particles (0.3–10 µm) were continuously measured at the wound using an Optical Particle Sizer. Particle counts were compared between standard care (exposure to ambient air), and HumiGard conditions using the Mann–Whitney test. Results HumiGard significantly reduced airborne particle counts at the surgical site. Median particle counts were reduced by 61% compared to standard care (p < 0.0001), excluding measurements during bone saw use. Particle counts dropped immediately when HumiGard was turned on and increased again when turned off, indicating active deflection of exogenous particles. The device integrated seamlessly into the surgical workflow without impeding tool or hand movement. Conclusion This pilot study demonstrates that HumiGard effectively reduced surgical site airborne particle counts during a dynamic cadaveric model of total hip arthroplasty. These findings suggest HumiGard may be a valuable addition to current infection prevention protocols, helping to minimise airborne particle contamination and potentially reduce the risk of surgical site infection.

ABSTRACT Exposures to traffic-related emissions are known to be responsible for diseases and increased mortality. Waste collection truck (WCT) drivers spend most of their time in microenvironments contaminated by these emissions and are also exposed to some pathogenic bioaerosols. To prevent WCT driver exposure, the cabin air filter (CAF) appears as one of the most useful equipment. No standard prescribing CAF efficiency levels for general or professional use was developed. Existing test procedures overlook particles smaller than 300 nm, such as diesel soot or certain bioaerosols, and no previous study has specifically addressed WCT cabin air filters or their clogging under real waste collection conditions. The aim of this work was to evaluate, for a range of particle sizes including ultrafine particles (UFP), the collection efficiency and pressure drop of the CAF media used in WCTs, and to study their evolution after clogging under real waste collection conditions. All the tested CAF models exhibited the typical U-shape curve of fractional collection efficiency with low to medium minimum collection efficiency ranging between 1.3% and 42.5%, depending on the filtration velocity. Statistical analysis indicated that CAF media are relatively homogenous across their filtration area and that variations in efficiency and pressure drop were mainly due to differences in clogging levels or initial state conditions. Compared to data available for private vehicles, CAF clogging appears to be more severe under waste collection conditions. Given the diversity of particulate contaminants, the low to moderate performances of current CAFs, and the exposure of WCT drivers, this study highlights the need for improved and more reliable protection. It is therefore essential to develop specific regulations or standards for CAFs, including systematic measurements of fractional collection efficiency over a broad particle size range, from UFP to micron-sized particles. The issue of preventive CAF replacement should also be addressed. Implications: Waste collection truck (WCT) drivers spend most of their time in micro-environments contaminated by traffic-related emissions and work-related bioaerosols. No previous study has assessed the performance of cabin air filters (CAF) on WCTs as a function of particle size, and their evolution in the event of clogging under real waste collection conditions. This research highlights the fact that WCT cabin air filters exhibit highly variable, and only low to medium, minimum collection efficiencies. Waste collection conditions also accelerated the filter clogging compared with literature data on nonprofessional use of CAFs. Given the size of the particles to which WCT drivers are exposed and their adverse health effects, this study demonstrates the need for more effective and reliable protection. This implies the development of specific regulations and standards for CAF performance and testing, including systematic measurements of fractional collection efficiency over a wide range of particle sizes, from ultrafine to micron-sized particles. These regulations should also explore the definition of more precise and adapted guidelines for CAF replacements to prevent the decrease in air exchange rate and the release in the cabin of deposited particles or of fraction of microbial colonies. Finally, all professional drivers, not just WCT workers, could benefit from such specific regulations.

Many space missions using High-Altitude Platforms (HAPs) are designed to measure contaminant particles in the stratosphere. However, there is no previous performance analysis of the sensors installed in the HAP in terms of the energy required by the detection system and the efficiency of the experiment. In this regard, it is not possible to assess the number of measurements that may be taken by the mission and the energy that it will consume in advance. Considering that energy resources are extremely limited in these space missions, especially in HAPs attached to hot-air balloons that effectively provide High-Altitude Platforms (HAPs), where the weight of the payload is of major importance to the success of the mission, a previous analysis is required to account for the feasibility and pertinence of the contaminant detection system. Building on this, we propose a mathematical analysis to determine the energy consumption of the measurement system based on the potential trajectories and the particle density. Also, the analysis provides an estimation of the number of particles that can be detected by the experiment in order to determine the performance of the sensor system. The model is based on an MMPP-2 (Markov Modulated Poisson Process with 2 states) model under exponential distribution assumptions, which provides a basic model that can be easily extended to other distributions in future works.

Detection of plant-derived silica particle contamination in wheat flour: A first step toward understanding possible dietary exposure

Microplastics are emerging pollutants that threaten aquatic ecosystems and global water safety. This research introduces an integrated IoT and AI-based system designed for real-time detection of microplastic particles in water samples. The system employs high-resolution microscopy integrated with a Raspberry Pi platform, utilizing machine learning models trained to identify and classify microplastic types based on size and shape. Data captured by the camera is processed and transmitted via MQTT to a centralized dashboard, providing live visualization of contamination levels, particle types, and water quality parameters. Validation using simulated datasets demonstrates detection accuracy exceeding 95%, with potential to scale for environmental monitoring across multiple sites. This work highlights a cost-effective, scalable approach for continuous water quality assessment, contributing to environmental protection and pollution management efforts.

Scanning electron microscopy with combined backscattered electron and X-ray imaging (SEM-BEX) represents a new way to conduct direct visual assessment and elemental characterisation of particles in environmental samples up to 18× faster than standard scanning electron microscopy techniques. SEM-BEX provides all element maps combined with back-scattered electron microscopy, which allows the detection of the elemental composition of individual particles, such as microplastics and others, in a semi-automated fashion. Detection of characteristic elements leads to further quantification of specific particles. This provides improved versatility compared to the elemental scans provided by standalone energy-dispersive X-ray spectroscopy (EDX) techniques and strongly increases multi-sample throughput speeds. The applications of this new technology for environmental contamination research include estimations on the morphology and distribution of microplastics and other particles alongside their interaction with micro-organisms and toxicity assessments by tracing the transport of trace metals through the environment on both contaminant (microplastics) and natural (suspended sediment) vectors. This study used filtered samples from the Cát Bà Islands of Viet Nam to assess the applicability of SEM-BEX to environmental contamination research, our results indicate that microplastics and other particles can be physically and chemically characterised across all samples down to a minimum particle size of 5 µm2, in addition, we show that SEM-BEX is particularly powerful for identifying transparent fragments that are otherwise missed by optical studies. Trace metals were also detected, including Cr, Ti, and Hg, which might be due to pigment composition in paints or plastics, or adsorbed onto particles from the environment. Ultimately, SEM-BEX has broad applications as a rapid screening tool for environmental assessments in identifying contamination hot-spots before conducting particle-specific analysis (such as Raman spectroscopy). Further potential also exists to accelerate screening using artificial intelligence machine learning.

Plasma-enhanced chemical vapor deposition (PECVD) is a key technology in semiconductor manufacturing due to its ability to form uniform and precise thin films at low temperatures. However, components such as showerheads, which serve as both electrodes and gas distributors, are continuously exposed to high-energy plasma and fluorine-based gases. This prolonged exposure results in material degradation, particulate contamination, and a decline in process reliability. To mitigate these issues, protective coatings with excellent plasma resistance, corrosion resistance, and mechanical stability are essential.This study proposes a multilayer coating system composed of anodized aluminum oxide (Al₂O₃) and atomic layer deposited (ALD) yttrium oxide (Y₂O₃). The Al₂O₃ layer, approximately 300 nm thick, acts as a dense buffer layer that prevents cracking or delamination of the brittle Y₂O₃ top layer, which can otherwise occur due to thermal stress from the mismatch in thermal expansion with the aluminum substrate. Densification of the Al₂O₃ layer was achieved by varying the holding time after reaching the target anodizing voltage, and its structural properties were evaluated using electrochemical analysis (EIS, Tafel) and morphological characterization via FIB, SEM, and TEM.A dense Y₂O₃ layer was subsequently deposited onto the Al₂O₃ using ALD, and both the single-layer Al₂O₃ and Al₂O₃–Y₂O₃ multilayer coatings were subjected to CF₄/O₂ plasma to assess their plasma resistance. Surface analysis revealed the formation of Al–F, Y–F, and Y–O–F compounds, and the Y₂O₃ layer exhibited approximately 2.7 times higher etch resistance compared to Al₂O₃. Nanoindentation measurements further indicated that the hardness of Y₂O₃ was approximately 2.09 times greater than that of Al₂O₃, confirming its mechanical reinforcement capability.These findings suggest that the Al₂O₃–Y₂O₃ multilayer architecture offers a robust and scalable protective strategy for improving the thermal, mechanical, and chemical durability of PECVD components in advanced semiconductor processing environments. Figure 1

Under ultra-high-pressure full-ocean-depth conditions, the rolling bearings of seawater pumps are often subjected to coupled stress conditions, including high external pressure, oil–water emulsification, and sustained high loads. Early failure tends to occur, which severely compromises system stability and reliability. This study focuses on identifying the typical failure mechanisms of bearings and proposing key optimization measures. A high-pressure experimental system rated at 120 MPa was constructed. Long-term water injection and drainage cycling tests were performed, followed by teardown inspections of failed prototypes. The bearing degradation was found to involve multiple failure modes, including rolling element fracture, cage breakage, lubricant emulsification, and three-dimensional embedded abrasive wear. The combined effects of lubricant degradation and particulate contamination primarily caused these failures. Comparative tests were conducted on ceramic bearings, PEEK bearings, and tapered roller bearings. The results confirmed that the tapered roller bearing exhibited superior environmental adaptability under lubrication with No. 10 aviation hydraulic oil. To enhance system performance, two engineering measures were proposed: (1) the use of heavy-duty tapered roller bearings to increase load capacity and fatigue life; (2) the addition of molybdenum disulfide (MoS₂) anti-wear additives to the lubricant to improve lubrication stability and wear resistance. Validation results showed that, after optimization, the prototype achieved significantly higher mechanical efficiency under 120 MPa conditions, and bearing wear was substantially reduced. These findings provide theoretical support and engineering guidance for selecting bearings and developing lubrication strategies in high-pressure, deep-sea hydraulic systems.

Environmental contamination critically affects the durability and performance of lubricants in machine components. Over long operating periods, particles and water ingress through degraded seals accelerate grease degradation and deteriorate tribological behavior. This study evaluates the effects of SiO2 particle concentration and water contamination, alone and in combination, on the performance of calcium-based grease in bearing steel contacts. Friction coefficients, grease temperatures, wear, pitting, and vibration signals were analyzed. The results show that an increase in particle concentration raised both friction and temperature, leading to more severe wear and pitting. The addition of 0.6 wt% water reduced fluctuations in friction and temperature, but when combined with high particle concentrations, it significantly worsened wear and pitting. The vibration-based energy ratio correlated strongly with pitting evolution, highlighting its potential as a sensitive parameter for monitoring surface fatigue. These findings provide insights into lubricant degradation under contaminated conditions and offer guidance for improving the reliability of lubricated systems.

Systematic characterization of mammalian extracellular vesicles using nano-flow cytometry

This paper presents the development of an innovative optical ball grid array (OBGA) packaging structure for automotive applications focused on process development, optimization and achieving the Automotive Electronics Council (AEC) AEC-Q100 Grade 2 reliability requirements. This new concept expands the package portfolio beyond the current cavity packages used for microelectromechanical systems (MEMS) products in production today. The innovative package features a glass lid that replaces the traditional metal or liquid crystal polymer (LCP) lid on MEMS products, eliminating the need for venting holes. This design change helps prevent particle contamination in the sensor area, enhancing the overall reliability and performance of the optical sensors. The optimized cavity package technology is applied to an optical sensor product and its effectiveness was confirmed through a feasibility study and reliability testing.