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Oil contamination resulting from externally ingested particles is one of the major causes of journal bearing failure in industrial machinery. The present study has been carried out to assess the case of externally ingested particle contaminants in a journal bearing lubrication using acoustic emission (AE) and vibration monitoring techniques. Besides quantitative evaluation, the features of AE and vibration spectra have been classified and key parameters for condition monitoring deduced. Furthermore, cases involving different particles sizes and concentrations have been exhaustively examined and illustrated; and the capability of these two methods described in terms of detectability.

Continuous innovations in lithography have led to the advancement of integrated chips for decades. To extend the so-called Moore's Law, chipmakers started to adopt Extreme Ultraviolet Lithography (EUVL) and have extended the use of EUV in their mass production. For the mass production using EUV lithography, EUV pellicles will are essential to prevent unexpected particle-induced yield drop and to promote productivity. However, the structure of the current EUV pellicle is different from that of optical pellicles. Thus, a new type of mounting and demounting system for EUV pellicle is required. The first generation of EUV pellicle mounting and demounting tools allowed chipmakers to handle EUV pellicles at their R&D levels. However, due to many manual processes involved with the first generation, it is necessary to introduce a fully automated tool to increase throughput and minimize particle contamination.

Lack of technical cleanliness and particle contaminations in Lithium-ion battery manufacturing affect the performance of batteries which are a risk for the safety and quality of the product. Therefore, part of the manufacturing process occurs inside the Clean and Dry room area to maintain technical cleanliness. This paper aims to provide a framework to control particle contamination inside the Clean and Dry room and strengthen the product's quality and safety. A literature study was conducted, which was completed by a field study at Northvolt Labs in Västerås to achieve the study's aims. The study contributes to existing theories by providing a framework to find root causes of particle contamination in the manufacturing process based on the existing literature and standards. The Six Sigma problem-solving methodology DMAIC was implemented to conduct the field study. A risk assessment was conducted to find the possible threats toward technical cleanliness in the cell assembly process. The risk sources were identified by implementing measurement methods from relevant standards. The results indicate a high risk for technical cleanliness are coming from the decontamination method, material, machines, and environment. Furthermore, several recommendations were given that are expected to decrease the amount of nonconformity in the process. Brist på teknisk renhet och partikelföroreningar vid tillverkning av litiumjonbatterier påverkar dess prestanda och utgör en risk för produktens säkerhet och kvalitet. Därför sker en del av tillverkningsprocessen i ett Clean & Dry rum för att upprätthålla teknisk renhet. Denna uppsats syftar till att ge ett ramverk för att kontrollera partikelföroreningar och därmed stärka produktens kvalitet och säkerhet. För att uppnå syftet genomfördes först en litteraturstudie vilket vidare kompletterades med en fältstudie vid Northvolt Labs i Västerås. Studien bidrar till befintliga teorier genom att tillhandahålla ett ramverk för att hitta och åtgärda rotorsaker till partikelkontaminering i tillverkningsprocessen baserat på befintlig litteratur och standarder. Sex Sigma problemlösningsmetoden DMAIC implementerades för att genomföra fältstudien. En riskbedömning genomfördes för att hitta riskfyllda aktiviteter i processen. Vidare implementerades mätmetoder från relevanta standarder för att mäta kontamineringsnivån. Resultaten indikerar stor risk för tekniskrenhet från saneringsmetoder, material, maskiner och miljön. Vidare rekommenderas flera åtgärder för att underhålla tekniskrenhet vilka förväntas minska avvikelser i processen.

BACKGROUND: Surgical helmet systems commonly are stand-alone systems with a single fan blowing air into the suit, creating positive pressure that blows particles out through areas of low resistance, possibly contaminating surgical attire and the surgical field. Two-fan systems were developed more recently to release spent air, also theoretically lowering pressure in the suit and decreasing the aforementioned risk of particle contamination. To our knowledge no study to date has measured the potential differences in gown particle contamination to support this hypothesis. QUESTIONS/PURPOSES: We compared a commonly used single-fan system versus a two-fan system and asked: (1) Which fan system results in less gown particle contamination? (2) Are there differences between the systems in the location of contamination? METHODS: Using an existing experimental study model, two surgeons performed five 30-minute TKA simulations comparing a single-fan to a double-fan helmet system after applying fluorescent powder to the hands, axillae, and chest. Both are two-piece hood and gown systems. The single-fan sits on top of the helmet blowing air into the suit; the double-fan system has a second fan positioned at the rear blowing out spent air. Ultraviolet light-enhanced photographs were subsequently obtained of the flexor and extensor surfaces of the arms, axillary areas, and front and back of the chest. We chose these locations because they all contain either a seam or an overlap between gown and hood or gloves through which particles can escape. The images were scored for contamination on a scale of 1 (zero specks) to 4 (> 100 specks) by three independent observers. Interobserver correlation was assessed through Spearman’s test yielding 0.91 (95% CI 0.86 to 0.94; p < 0.0001), 0.81 (95% CI 0.73 to 0.87; p < 0.0001) and 0.87 (95% CI 0.80 to 0.91; p < 0.0001) between observers 1 and 2, observers 1 and 3, and observers 2 and 3, rendering the used scale reliable. Results of the observers were averaged and compared using the Mann-Whitney U test. RESULTS: There was no difference in overall gown particle contamination between the systems (overall single-fan median contamination score 2.5 of 4 [interquartile range Q1-Q3 0-3.42] versus double fan 1 out of 4 (Q1-Q3 0-3); p = 0.082), but all tests showed there was contamination at the gown-glove interface. In general, there were few differences between the two systems in terms of location of the contamination; however, when comparing only the axillary regions, we found that the single-fan group (median score 3.67 [Q1-Q3 3-4]) showed more contamination than the double-fan group (2.33 [Q1-Q3 0-3.08]); p = 0.01. CONCLUSION: We found no difference in gown particle contamination between a single-fan and a double-fan helmet design. However, we note that contamination was present in all tests with both systems, so surgeons should not assume that these systems provide a contamination-free environment. CLINICAL RELEVANCE: When using such helmets, the surgeon should not place items close to the axillary region because the seam of the gown may have low resistance to particle contamination. Gown designs could be improved by creating better seals, especially at the arm-body seam.

Ovaj završni rad prikazuje proces razvoja i konstruiranja premjestivog uređaja za pročišćavanje zraka vodom. Prvo je napravljena analiza tržišta i kompletnih rješenja te funkcijska struktura proizvoda. Za potrebne funkcije proizvoda u morfološkoj matrici su dani prijedlozi rješenja te su na temelju njih generirana dva koncepta. Vrednovanjem je odabran bolji koji je potom detaljno razrađen. Za odabrani koncept izrađen je 3D model korištenjem Solidworks programskog paketa, proveden potreban proračun komponenti te izrađena tehnička dokumentacija u zadanom opsegu. This bachelor thesis shows the process of developing and designing a mobile wet dust collector. In the beginning of the thesis market analysis and functional structure of the product was made. For different functions of the product several different solutions were given. Based on that two concepts were generated. Based on evaluation of them the better one was chosen. The chosen concept was then fully elaborated. For the chosen concept 3D model was made using Solidworks, alongside with required calculations and technical documentation in foreseen range.

В статье рассмотрены конструкция и принцип работы экспресс-анализатора для определения объемного содержания загрязнений в рабочей жидкости гидросистем машин используемых в дорожном строительстве. Приведены расчеты для определения длины заполнения стеклянной трубки частичками загрязнения, объема специального стакана, состоящего из стального усеченного конуса и стеклянной трубки и движения частицы в жидкости., The article discusses the structure and principle of operation of the express-analyzer for determining the voluminous content of in the working fl uid of hydraulic systems of machines used in road construction. The calculation is given for fi lling the glass tube with particles of contaminants, the volume of a special glass consisting of a steel truncated cone and a glass tube and the movement of a particle in a fl uid., №8(134) (2020)

The presence of contaminants in polyethylene terephthalate (PET) bottles and derived materials from the various steps in the recycling loop is studied. Based on these measurements, a model is proposed to generically describe the accumulation of these contaminants within closed‐loop recycling schemes for PET bottles. The measured levels of particle contamination and chlorine content of PET bottles, pellets, and intermediate recycling products are used to derive the modelling parameters. Previously determined relations between these measured parameters and critical bottle properties are used to model the effect of the accumulation of the contaminants on the bottle properties. The measurements reveal that the type of collection system influences the accumulation of contaminants in PET bottles greatly. PET bottles in mono‐collection systems accumulate less contaminants than PET bottles in co‐collection systems do. Therefore, PET bottles within recycling schemes using mono‐collection systems can contain more recycled content than those from co‐collection systems, without exceeding acceptation limits on critical bottle properties such as haziness, yellowing, and migration.

Well working hydraulic systems need clean hydraulic oil. Therefore, the system must ensure the separation of molecular, gaseous, liquid and solid contaminations. The key element of the separation of contaminants is the hydraulic reservoir. Solid particles are a major source of maintenance costs and machine downtime. Thus, an Euler-Euler-Lagrange multiphase CFD model to predict the transport of solid particles in hydraulic reservoirs was developed. The CFD model identifies and predicts the particle accumulation areas and is used to train port-to-port transfer functions, which can be used in system models to simulate the long-term contamination levels of hydraulic systems. The experimental detection of dynamic particle contamination levels and particle accumulation areas validate and confirm the CFD and the system model. Both models in combination allow for parameter and design studies to improve the fluid management of hydraulic reservoirs.

The effect of recycled content and type of recycled poly (ethylene terephthalate) (rPET) on the haziness; colour parameters L*, a*, and b*; total colour change; ultraviolet‐visual spectrum (UV‐VIS) absorption; and environmental stress cracking (ESC) of PET bottles was studied. Three series of PET bottles were made at a small scale production facility with same type of virgin PET and three different types of rPET with recycled contents of 25%, 50%, 75%, and 100%. Also, the particle contamination of the produced PET bottles was studied by dissolving bottle fragments and counting the insoluble particles. A linear relationship was found between the haziness of PET bottles and the particle contamination, with a coefficient of determination of 0.96. Linear relationships were also found between the colour parameters L* and b* and the particle contamination of the PET bottles, but the slope differed for each type of rPET. The origin of rPET (mono‐collection or cocollection) seems to be the crucial factor determining particle contamination and colour of the produced bottles. No correlation was found between the recycled content and the incidence of ESC. However, PET bottles in which high intrinsic viscosity (IV) values were measured showed lower chances of ESC than PET bottles with low IV values

Advanced data analysis techniques can be implemented to quantitatively assess particle contamination data in state-of-the-art chemical distribution systems. Through examining the distribution of the rate of particle detection compared to Poisson’s distribution, it is possible to determine if particle variations are random or systematic and allow for the focus of improvement efforts to reduce particle levels with time. By analyzing the particle contamination data in the frequency domain via Fourier transform analyses, periodic cycles of contamination can be identified with the goal of associating contamination events with activities within the chemical delivery system.

The detection of plastic deformation caused by particle contamination in rolling element bearings using acoustic emission is reliable at low speeds as shown in several studies. However, there are no studies at greater speeds of the detection of plastic deformation by acoustic emission in rolling element bearings. The acoustic emission signals of rolling element bearings have, however, been shown to be dominated by transient force signals which are elastic waves caused by transient forces acting at the raceway surface. The results of the test showed a dominance of transient force signals at elevated speeds, which masks signals caused by plastic deformation and prohibits the detection of particle contamination, while at low rotational speed plastic deformation is detected by acoustic emission.

Particle contamination is a major problem in the hard disk drive (HDD) manufacturing industry, and the tightening of screws during the manufacturing process has been found to be one of the main sources of particles. The aim of this research is to study the possibility of using molybdenum disulfide titanium (MoS2T) composite coating to reduce stainless steel particles that are generated in the screw-tightening process in HDD. The experiments used for simulating dry sliding wear mechanisms were carried out by using a TriboGear machine. MoS2T film was coated on an S2 tool steel bit and a martensitic 410 stainless steel screw; the film was deposited by the sputtering technique with a film thickness of 1·0 μm. Dry sliding wear mechanisms were simulated under both single and loading cycle contact wear. The results showed that the use of solid lubricant MoS2T coating is capable of total prevention of generation of stainless steel particles due to adhesive wear. This study also shows that no stainless steel particles were found on the carbon tape, suggesting that no particles were generated in the single loading test. However, the coating showed surface wear, with the film gradually peeling off during loading cycle contact wear experiments.

Nowadays, power transformer is most crucial electrical equipment in a power system. Researcher has been emphasized a lot of researches on natural ester oils to replace mineral oil that act as insulating liquid in power transformer. In this paper, an effort has been made to investigate corn oil (CO) as alternate liquid insulation to mineral oil (MO). Copper are used as particles contamination in this project. There are 12 oil samples has been prepared. Two samples which are pure MO and pure CO for before aging and 10 oil samples which are five samples of pure MO and five samples of pure CO for after aging. The particles contamination that used in this experiment which is copper with different size of length was added in each sample for after aging. The length sizes of copper were 5cm, 10cm, 15 cm, 20cm, 25cm and 30cm. In this report, the investigation of AC breakdown voltage involved two stages which are before aging and after aging. For before aging, two oil samples are only conducting AC breakdown voltage. Moreover, for after aging another 10 sample has been heated in the oven with temperature 115°C at 96 hours in order to investigate the effect of particle contamination in the transformer oil. From the experiment result that conducted, pure CO higher value of AC breakdown voltage than pure MO for before aging. But, after aging process, the value of pure MO with difference size of copper is higher than pure CO. It show that CO is good oil insulator to replaced MO for the future, but for use in long term, MO still the best insulator because has higher AC breakdown voltage than CO after aging process.

The purpose of pellicles is to protect reticles from particle contamination, thus reducing the number of defects and increasing yield. In this paper we show how recent progress in pellicle technology has succeeded in solving the main challenges in imaging with EUV pellicles. We demonstrate this using the recent results of imaging tests in scanner, EUV reflectivity measurements, and lifetime testing. EUV light reflectivity of pellicles is one of the effects that have negatively impacted imaging with pellicles in the past. Light reflected from pellicles leads to the overexposure of neighboring fields in the corners and edges. Tests with pellicles produced using a new process show EUV reflectivity within specification of 0.04%, and measured impact on critical dimension in the corners below 0.15nm for multiple pellicles. Lifetime performance was tested by exposing up to 3000 wafers with a pellicle while periodically assessing the stability of imaging metrics. The lithometrics studies include: critical dimension (CD) and critical dimension uniformity (CDU), and contrast (via line width roughness). DoseMapper, which is an EUV scanner application developed to improve CDU, was applied during the lifetime test. Here we show that it can successfully reduce the pellicle-induced CDU and CDU over lifetime (previously shown to be dominated by pellicle EUV transmission drift). Our results using DoseMapper show that whilst intrafield CDU 3sigma increases over lifetime, it stays comfortably within the 1.1nm NXE3400 ATP specification using DoseMapper.

Since 1945, a series of nuclear and radiological sources have contributed to the release of radioactive particles containing refractory elements into the environment. Several years of research have demonstrated that the particle composition will depend on the source, while the release scenarios will influence particle properties of relevance for environmental transfer. Radioactive particles can also carry sufficient amount of radioactivity (MBq) and represent point sources of radiological concern. Most radiological assessment models, however, are based on bulk concentrations, assuming that radionuclides in the environment are evenly distributed. In contrast, radioactive particles and thereby doses are unevenly distributed, while leaching of radionuclides from particles prior to measurements can be partial, potentially leading to underestimation of inventories. For areas affected by particle contamination, information on particle characteristics controlling the particle weathering rates and remobilization of particle associated radionuclides will therefore be essential to reduce the overall uncertainties of the impact assessments. The present paper will focus on analytical strategies, from screening techniques applicable for identifying hot spots in the field, fractionation techniques and single particle extraction techniques as a preparatory mean to apply non-destructive solid state speciation techniques, till leaching techniques applied sequentially to obtain information on binding mechanisms, mobility and potential bioavailability. Thus, a combination of techniques should be utilized to characterize radioactive particles in order to improve environmental assessments for areas affected by radioactive particle fallout.

The Ancient Nubians have historically been renowned for their significant contributions to medicine. In spite of this, extremely poor oral health plagued this population. Paleopathological studies depict pronounced dental deterioration patterns far exceeding normal physiological progression. The advanced wear is popularly attributed to sand particle contamination of their daily diets. However, considering that individual wear mechanisms rarely act in isolation, we propose that adverse biochemical factors arising from regular consumption of tetracycline- fortified beer induced calcium malabsorption, and thus provided a synergistic diathesis in potentiating these effects. We examine these implications within the context of prevalent therapeutic remedies, bone fluorescence labeling data, and sociocultural attitudes when making the link between tetracycline and the compromised integrity of teeth, while citing the emergence of antibiotics actually predating formally-accepted convention.

With the introduction of the NXE:3400B scanner, ASML has brought EUV to High-Volume Manufacturing (HVM). In this context, ASML is pursuing a dual-path approach towards zero reticle defectivity: EUV-compatible pellicle or zero particles towards reticle by advanced particle contamination control. This paper will focus on the latter approach of advanced particle contamination control and will show that we are able to reduce particle contamination towards reticle to a level that is compatible with HVM requirements for sub-10nm node lithography.

In the context of space-based optics, contamination due to particle deposition on the optics is inevitable and constitutes a critical issue. This gets more challenging for the sensitive heterodyne measurements of the Laser Interferometer Space Antenna (LISA), the space-based gravitational wave observatory to be launched in 2034. Therefore, table-top experiments need to be developed for a better understanding of how micrometer to millimeter sized dust particles, present on optical surfaces, affect LISA measurements. In this work, we present an experimental setup for the simultaneous measurement of the coherent backscattering and the monitoring of particles deposition on the optics to be tested. The results of the first measurements are presented and discussed in this article.

Heat transfer fluid (HTF) cleanliness is critical to the effectiveness and safety of an HTF system. Routine monitoring of HTF condition is a critical part of ongoing HTF system maintenance. However, the condition of any fluid introduced into a HTF system needs to be monitored closely to ensure that foreign contaminants are not introduced. Such contaminants act to accelerate the ageing of an HTF once in operation. The current research concerns the flushing and cleaning protocol that is used to remove foreign contaminants during the building of a new HTF system. The current study was performed in Scandinavia for a client building a new HTF system that had a capacity of 100 metric tons. The system was flushed with Globaltherm® C1 was used to flush and clean the system prior to filling with a synthetic HTF. The value of the protocol was assessed in terms of its ability to remove contaminants – water, environmental and system build contaminants. The protocol involved the use of a fine filter (15 microns pores) and laboratory analysis to assess cleanliness of the fluid. The results from nineteen fluid samples are presented herein. Results show the presence of water and particle contaminants (4, 6 and 14 microns in size) including silicon, aluminium, iron, calcium and zinc. The flushing and cleaning fluid works by suspending particles in solution and these are subsequently drained from the HTF system. The detection of particles in the fluid demonstrates that the flushing and cleaning fluid and the protocol are effective in removing finer particles from a system. Further analysis assessed the relationship between water and particle contaminants. Results showed a positive association between water and the presence of larger particles (i.e., 14 microns). No association was found between water and smaller particles (4 and 6 microns). These data highlight the value of monitoring both water and particle contamination, and that water may be a substitute method to measuring particles directly. The presence of water in a fluid can be observed and detected onsite, so this may be an early sign of other contaminants present in a newly build HTF system. To conclude, the flushing and cleaning protocol described herein is effective in the removal of contaminants during a HTF system build. This protocol has been shown to be effective by subsequent laboratory analysis. The presence of water may be an early sign of environmental contamination and the formation of rust.

In the present experimental study, abrasive water jet (AWJ) cutting tests were conducted on D2 steel by different jet impingement angles and abrasive mesh sizes. The experimental data was statistically analyzed using the simos–grey relational method and ANOVA test. In addition, the outcome of influencing cutting parameters, namely jet pressure, jet impingement angle, and abrasive mesh size on the different response parameters, namely, the jet penetration, material removal rate, taper ratio, roughness, and topography, were studied. Micro-hardness test and surface morphology analysis were employed to examine the D2 cut surfaces at different AWJ cutting conditions. The chemical element study was performed to determine the abrasive particle contamination in the AWJ kerf wall cut surfaces. The ANOVA test result indicated the jet pressure and jet impingement angle as the influencing process parameters affecting the various performance characteristics of AWJ cutting. The overall AWJ cutting performance o...

Protein drug products play an important role in the treatment of severe diseases. However, due to the instability of these complex molecules, protein aggregates can form which can compromise drug safety and efficacy including immunogenic reactions. In-line filtration during the administration of these drugs can serve as a final safeguarding step to protect patients from risks associated with proteinaceous particles. A unique analysis of more than 300 marketed protein drug products revealed that already around 16% of all these products are filtered during preparation or administration. Further, the research revealed that no standardized filtration practice exists. Broad variances regarding filter membrane or pore size are found and sometimes no specifications are mentioned at all. The benefits as well as possible negative impacts of filtration like filter shedding, extractables or drug adsorption are critically assessed. Several proposals to improve the current filtration practice and to expand the number of in-line filtered protein drug products are made. The suggestions include the demand for the specific usage of one filter membrane type, the establishment of a filtration routine for unfiltered protein drugs and a statistical analysis between filtered and non-filtered products with similar formulations to identify possible differences in the immunogenicity rate.

The lack of quantitative risk assessment of airborne transmission of COVID-19 under practical settings leads to large uncertainties and inconsistencies in our preventive measures. Combining in situ measurements and computational fluid dynamics simulations, we quantify the exhaled particles from normal respiratory behaviors and their transport under elevator, small classroom, and supermarket settings to evaluate the risk of inhaling potentially virus-containing particles. Our results show that the design of ventilation is critical for reducing the risk of particle encounters. Inappropriate design can significantly limit the efficiency of particle removal, create local hot spots with orders of magnitude higher risks, and enhance particle deposition causing surface contamination. Additionally, our measurements reveal the presence of a substantial fraction of faceted particles from normal breathing and its strong correlation with breathing depth., Highlights • Provide in situ characterization of particle generation through normal breathing. • Reveal presence of droplet and crystalline particles generated through breathing. • Risk assessment of airborne transmission of infectious diseases through virus-containing particles. • Inappropriate ventilation enhances the risk of airborne disease transmission.

Plastic particles are small micro and nano range materials internationally produced for industrial applications or as a result of the breakdown of larger plastics. The accumulation of plastic particles varies spatially and temporally, with locations, hydrodynamic conditions, environmental pressure, time, and anthropogenic factors accounting for the disparities in dispersal and distribution. The accelerating global release of plastic particles into the environment seems unending, with long-term consequences for water quality, biodiversity, biological conservation, and human health. In this paper, we review the formation, presence, and toxicity of plastic particles in water, land, and air. Plastic wastes and plastic particles are increasing in abundance every year with increased consumption and rise in the global population. These materials are easily transported over long distances and become ubiquitous in their distribution on land, water, and air with unknown and unproven ecological and human health risks. Notwithstanding the potential threats to ecological health, literary records of plastic particle contamination of environmental media in Africa are very scanty. Managing environmental waste plastics and plastic particles and ensuring effective intervention policies and practices requires an understanding of plastic particles sources, transport, and fate, through regional and international collaboration, and interdisciplinary research. In consideration of the potential threats of plastic particles to ecological functions and human health risks, we recommend specific regulation of microplastics in consumer products. The information contained in this paper adds to the growing body of knowledge in the study of micro- and nano-plastic particles worldwide but with particular reference to developing countries.