Search

Epidemiologic research and quantitative risk assessment play a crucial role in transferring fundamental scientific knowledge to policymakers so they can take action to reduce the burden of ambient air pollution. This commentary addresses several challenges in quantitative risk assessment of air pollution that require close attention. The background to this discussion provides a summary of and conclusions from the epidemiological evidence on ambient air pollution and health outcomes accumulated since the 1990s. We focus on identifying relevant exposure-health outcome pairs, the associated concentration-response functions to be applied in a risk assessment, and several caveats in their application. We propose a structured and comprehensive framework for assessing the evidence levels associated with each exposure-health outcome pair within a health impact assessment context. Specific issues regarding the use of global or regional concentration-response functions, their shape, and the range of applicability are discussed. [ABSTRACT FROM AUTHOR]

This study presents a comparative study on architecture‐dependent electrochemical properties of anodes made from aluminum particles and aluminum foil for lithium‐ion batteries (LIBs) application. The purity and other physicochemical features were analyzed by X‐ray diffraction (XRD), energy‐dispersive X‐ray spectroscopy (EDX), and scanning electron microscopy (SEM) methods. The electrochemical characteristics were determined by cycling voltammetry (CV) and galvanostatic charge/discharge (GCD) tests. The obtained results demonstrated that, due to the architecture nature of aluminum foil, the aluminum foil electrode had better conductivity and higher nucleation overpotential compared to the aluminum particles electrode, which involved other components such as PVDF as binder and carbon super P as conductive agent. Thus, the CV curves of the aluminum foil electrode showed sharper redox peaks with higher peak intensity. In addition, the aluminum foil electrode provided significantly higher initial capacity than that of the aluminum particles electrode. However, the architecture of the foil anode rendered it extremely prone to volume expansion during cycling, resulting in a fast and complete capacity fading just after 13 cycles. The anode made from aluminum particles, in contrast, witnessed slower capacity decay and ultimately stabilized at approximately 50 mAh g−1 for extending cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] Aqueous solutions of long-chain water-soluble sucrose ester surfactants exhibit non-trivial response to temperature variations, revealing a peak in viscosity around 40–50 °C. While previous investigations have explored the structures within sucrose stearate systems at various constant temperatures, a comprehensive understanding of the entire temperature dependence and the underlying molecular factors, contributing to this phenomenon is currently missing. Temperature dependent properties and supramolecular structures formed in aqueous solutions of commercial sucrose palmitate were examined using SAXS/WAXS, DSC, optical microscopy, rheological measurements, NMR, and cryo-TEM. The underlying mechanism governing this unusual behavior is revealed and is shown to relate to the mono- to di-esters ratio in the solutions. Solutions primarily containing sucrose monoesters (monoesters molecules ≳ 98% of all surfactant molecules) exhibit behavior typical of nonionic surfactants, with minimal changes with temperature. In contrast, the coexistence of mono- and di-esters results in the formation of discrete monodisperse diester particles and a network of partially fused diester particles at low temperature. As the temperature approaches the diesters' melting point, wormlike mixed micelles form, causing a viscosity peak. The height of this peak increases significantly with the diester concentration. Further temperature increase leads to fluidization of surfactant tails and formation of branched micelles, while excess diester molecules phase separate into distinct droplets. [ABSTRACT FROM AUTHOR]

We comment on the so-called negative result experiments (also known as null measurements, interaction-free measurements, and so on) in quantum mechanics (QM), in the light of the new general understanding of the quantum-measurement processes, proposed recently. All experiments of this kind (null measurements) can be understood as improper measurements with an intentionally biased detector set up, which introduces exclusion or selection of certain events. The prediction on the state of a microscopic system under study based on a null measurement is sometimes dramatically described as "wave-function collapse without any microsystem-detector interactions". Though certainly correct, such a prediction is just a consequence of the standard QM laws, not different from the situation in the so-called state-preparation procedure. Another closely related concept is the (first-class or) repeatable measurements. The verification of the prediction made by a null measurement requires eventually a standard unbiased measurement involving the microsystem-macroscopic detector interactions, which are nonadiabatic, irreversible processes of signal amplification. [ABSTRACT FROM AUTHOR]

Purpose: This research investigates the behavior of granulated sugar particles of different sizes in a rotating drum at varying speeds, using the discrete element method (DEM) as a mathematical modeling approach. Design/methodology/approach: The study conducted a data scan to determine both static and rolling friction coefficients. Based on benchmark studies, the Hertz–Mindlin contact model with rolling history elastic-plastic spring-dashpot (EPSD) and CDT (directional constant torque) models were employed to simulate the behavior of granulated sugar particles in a rotating drum under varying speeds. Findings: In this research, the static and rolling friction coefficients presented the best values for granulated sugar near 0.60 and 1.5, respectively, applying the CDT model. The method demonstrated great accuracy in replicating experimental data. Originality/value: This study enables comprehension of the behavior of the particles and particle system in a rotating drum at different speeds. The method may develop models that characterize and predict the main effects of particle systems to reduce project time and expense, especially in the food industry. [ABSTRACT FROM AUTHOR]

AMReX is a software framework for the development of block-structured mesh applications with adaptive mesh refinement (AMR). AMReX was initially developed and supported by the AMReX Co-Design Center as part of the U.S. DOE Exascale Computing Project (ECP), and is continuing to grow post-ECP. In addition to adding new functionality and performance improvements to the core AMReX framework, we have also developed a Python binding, pyAMReX, that provides a bridge between AMReX-based application codes and the data science ecosystem. pyAMReX provides zero-copy application GPU data access for AI/ML, in situ analysis and application coupling, and enables rapid, massively parallel prototyping. In this paper we review the overall functionality of AMReX and pyAMReX, focusing on new developments, new functionality, and optimizations of key operations. We also summarize capabilities of ECP projects that used AMReX and provide an overview of new, non-ECP applications. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the airborne exposure to aerosols according to the particle size distribution of three different spray types (nano-nozzled spray gun, low-temperature steam spray, and fogger) and compare the concentrations of inhaled aerosols between children and adults. Airborne aerosols released from three products were observed using size-segregated particle measurements, and particle concentrations deposited in the respiratory tracts of adults and children were estimated using multi-path particle dosimetry lung deposition models. All types of sprayers generated the most nanoparticles (~100 nm). Due to their higher respiratory rate than adults, a larger number of particles <1.0 μm deposited in the children's respiratory tracts was higher. The sequences of the total number of particles in the respiratory regions after spraying nano-nozzled spray gun and fogger were alveolar (AL)>tracheobronchial (TB)>head airway (HA) in adults and AL>HA>TB in children. Meanwhile, the trend of low-temperature steam spray was AL>TB>HA in adults and AL>TB>HA in children. [ABSTRACT FROM AUTHOR]

The international GEOTRACES program has been instrumental in demonstrating how marine sediments are a critical source of dissolved Fe to the world's oceans. Here, we present dissolved iron (dFe) from the GEOTRACES North Pacific GP15 section, which, alongside other sediment‐source tracers (including dissolved δ56Fe, Mn, 228Ra, and particulate Fe), allows for identification of the dFe provenance of three distinct dFe depth maxima at the Alaskan margin. Two of these (shelf and abyssal depths) are of local Alaskan sedimentary origin. The third, a mid‐depth dFe maximum with an absence of 228Ra, is an advected signal that, based on tracer data from Western Pacific GEOTRACES transects and circulation models, must be advected from sedimentary sources on the Asian margin, ∼5,000 km away. This study illustrates the importance of measuring diagnostic sedimentary tracers like radium when assigning local margins as sedimentary sources of marine trace metal budgets. Plain Language Summary: Iron is an essential, yet limiting, micronutrient for marine primary producers, and thus influences patterns of global oceanic primary productivity and carbon exchange. In recent years, the International GEOTRACES program has highlighted that marine sediments, hydrothermal vents, and atmospheric dust all supply dissolved iron to the oceans. Here, we investigated the sources of dissolved iron to the Eastern North Pacific Ocean, using samples collected on the U.S. GEOTRACES GP15 Pacific Meridional Cruise that sailed from Alaska to Tahiti in 2018. We identified three elevated dissolved iron features close to the Alaskan continental margin, with two originating from local sedimentary sources (shelf and abyss). The third, an intermediate depth dissolved iron plume that extends south into the gyre, is not of local sedimentary origin, but instead results from long‐distance transport of dissolved iron from Asian marginal sediment sources. A critical aspect of this study is the use of multiple chemical tracers such as radium, iron, and manganese, coupled with ocean circulation models, to correctly attribute the sources of trace metals to the ocean. Key Points: Three distinct dFe maxima were identified close to the Alaskan margin at different depths. Two are of local origin (shelf and abyssal)An intermediate depth dFe plume with an absence of Mn and Ra, is a distal advected signal from Asian margin sedimentary sources (5,000 km away)A multiple tracer approach of Fe, Mn, and Ra was necessary to rule out what appeared to be a local margin source [ABSTRACT FROM AUTHOR]

Carbon nanoparticle interactions with gases are central to many environmental and technical processes, but the underlying reaction kinetics and mechanisms are not well understood. Here, we investigate the oxidation and gasification of carbon nanoparticles by NO2 and O2 under combustion exhaust conditions. We build on a comprehensive experimental data set and use a kinetic multilayer model (KM‐GAP‐CARBON) to trace the uptake and release of gas molecules alongside the temporal evolution of particle size and surface composition. The experimental results are captured by a model mechanism that involves different types of carbon atoms (edge/plane‐like) and the formation of a reactive oxygen intermediate (activated CO complex) as the rate‐limiting step. A transition between distinct chemical regimes driven by NO2 at lower temperatures and O2 at higher temperatures is reflected by an increase in the observable activation energy from ∼ ${ \sim }$ 60 kJ/mol to ∼ ${ \sim }$ 130 kJ/mol. We derive energy profiles for three alternative reaction pathways that involve uni‐ or bimolecular decomposition of reactive oxygen intermediates. [ABSTRACT FROM AUTHOR]

Background/Objectives: The present work proposes a mathematical model able to describe the dissolution of poly-disperse drug spherical particles in a solution (Dissolution Rate Test—DRT). DRT is a pivotal test performed in the pharmaceutical field to qualitatively assess drug bioavailability. Methods: The proposed mathematical model relies on the key hallmarks of DRT, such as particle size distribution, solubility, wettability, hydrodynamic conditions in the dissolving liquid of finite dimensions, and possible re-crystallization during the dissolution process. The spherical shape of the drug particles was the only cue simplification applied. Two model drugs were considered to check model robustness: theophylline (both soluble and wettable) and praziquantel (both poorly soluble and wettable). Results: The DRT data analysis within the proposed model allows us to understand that for theophylline, the main resistance to dissolution is due to the boundary layer surrounding drug particles, whereas wettability plays a negligible role. Conversely, the effect of low wettability cannot be neglected for praziquantel. These results are validated by the determination of drug wettability performed while measuring the solid–liquid contact angle on four liquids with decreasing polarities. Moreover, the percentage of drug polarity was determined. Conclusions: The proposed mathematical model confirms the importance of the different physical phenomena leading the dissolution of poly-disperse solid drug particles in a solution. Although a comprehensive mathematical model was proposed and applied, the DRT data of theophylline and praziquantel was successfully fitted by means of just two fitting parameters. [ABSTRACT FROM AUTHOR]

Diesel engine exhaust (DEE) is carcinogenic and potentially hazardous for those working in close proximity to diesel-powered machines. This study characterizes workplace exposure to DEE and its associated particulate matter (PM) during outdoor construction activities. We sampled at 4 construction sites in the Copenhagen metropolitan area. We used portable constant-flow pumps and quartz-fiber filters to quantify personal exposure to elemental carbon (EC), and used real-time instruments to collect activity-based information about particle number and size distribution, as well as black carbon (BC) concentration. Full-shift measurements of EC concentration ranged from < 0.3 to 6.4 µg/m3. Geometric mean (GM) EC exposure was highest for ground workers (3.4 µg/m3 EC; geometric standard deviation, GSD = 1.3), followed by drilling rig operators (2.6 µg/m3 EC; GSD = 1.4). Exposure for non-drilling-rig machine operators (1.2 µg/m3 EC; GSD = 2.9) did not differ significantly from background (0.9 µg/m3 EC; GSD = 1.7). The maximum 15-min moving average concentration of BC was 17 µg/m3, and the highest recorded peak concentration was 44 µg/m3. In numbers, the particle size distributions were dominated by ultrafine particles ascribed to DEE and occasional welding activities at the sites. The average total particle number concentrations (PNCs) measured in near-field and far-field positions across all worksites were 10,600 (GSD = 3.0) and 6,000 (GSD = 2.8)/cm3, respectively. Sites with active drilling rigs saw significantly higher average total PNCs at their near-field stations (13,600, 32,000, and 9,700/cm3; GSD = 2.4, 3.4, and 2.4) than sites without (4,700/cm3; GSD = 1.6). Overall, the DEE exposures at these outdoor construction sites were below current occupational exposure limits for EC (10 µg/m3 in Denmark; 50 µg/m3 in the European Union), but extended durations of exposure to the observed DEE levels may still be a health risk. [ABSTRACT FROM AUTHOR]

In Europe, respiratory protective devices must be certified before they can be marketed. Among the parameters of interest, inward leakage (IL) characterizes the tightness between the face seal and the face, to verify that the device is well-designed. European standard EN 13274-1 (2001) and International Organization for Standardization (ISO) standard ISO 16900-1 (2019) specify that IL should be measured using sodium chloride (NaCl) aerosol or sulfur hexafluoride (SF6) gas. For reusable masks made of nonporous materials, both test agents are considered equally acceptable. However, the few studies that have compared IL values measured with various aerosols and gases have come to divergent conclusions. This work then aimed to measure IL with the test agents recommended by the standards to determine whether they are really equivalent. Since krypton (Kr) is an interesting candidate for replacing SF6 in standard tests, IL was assessed with SF6 and Kr simultaneously, and with NaCl aerosol using various calculation methods. Tests were carried out on 5 models of full-face masks donned on a headform connected to a breathing machine simulating 3 sinusoidal breathing rates of various intensities. The respirator fit on the headform was evaluated using a controlled negative pressure method to determine a manikin fit factor. Four scenarios were then tested to represent very poor, bad, good, and excellent fit. Gas concentration was measured using a mass spectrometer, and IL was calculated for SF6 and Kr. A combination of 3 devices allowed the determination of the number-based concentration of particles with diameters between 20 nm and 2 µm, and IL was calculated for each of the 33 channels, as well as using a cumulative number concentration. In addition, to comply with standards, a conversion was carried out to calculate IL using a cumulative mass concentration. The results of this work evidenced that the IL values measured with NaCl were systematically lower than those determined with gases. IL was also shown to vary with particle size, with a maximum value exceeding that calculated with cumulative concentrations (in number or mass). As part of the revision of the standards, protocols for measuring inward leakage should be redefined. On the one hand, acceptability thresholds should be re-evaluated according to the nature of the test agent (gas or aerosol), as it is clear that the 2 options do not give the same results for a given configuration. On the other hand, the aerosol leakage measurement protocol needs to be reworked to enable the measurement of a well-defined, robust, and reproducible inward leakage value. [ABSTRACT FROM AUTHOR]

• Coarser oat flours reduced postprandial glycemia when consumed in a porridge. • Finer oat flour porridge reduced appetite but did not impact food intake. • Adding coarse oat flour to common foods can increase health benefits. • Processing impacts the nutritional properties of oat flours. Consumption of oats is associated with lowered risks of type 2 diabetes and obesity. However, many oat-based products (e.g., breakfast cereals) use finely milled flours but are associated with health claims based on oats of larger particle sizes. The objective of this study was to test the hypothesis that increasing oat flour particle size will result in lower postprandial glycemia and appetite. Using a randomized-controlled, crossover design, 20 participants (10 males, 10 females; age: 25.3 ± 1.0 years; body mass index: 23.2 ± 0.6 kg/m2) consumed a serving of porridge made using 40 g of coarse (675.7 ± 19.6 µm), whole (443.3 ± 36.2 µm), fine (96.0 ± 2.1 µm), or a commercial (375.9 ± 14.8 µm) oat flour unmatched in available carbohydrate, protein, and dietary fiber content. After a 12-hour overnight fast, blood glucose, insulin, and appetite were measured at 15 to 30-minute intervals over 120 minutes posttreatment consumption. Coarse and whole flours led to lower blood glucose between 30 and 60 minutes (P <.02). Blood glucose area under the curve (AUC) was lower after coarse than fine and commercial oat flours (P < 0.03), and after whole than fine oat flour (P <.002). Both coarse and whole oat flours resulted in lower insulin AUC than finer flours (P <.05). Appetite AUC was lower after the commercial than coarse flour (P <.007). Controlling milling to produce coarser oat flour to add to common foods may have health benefits. This study was registered at ClinicalTrials.gov (NCT05291351). Healthy adults consumed porridge made using coarse, whole, fine, or commercial oat flour after a 12-hour overnight fast. Postprandial glycemia and appetite were assessed every 15 to 30 minutes over 120 minutes. Food intake was assessed at an ad libitum pizza meal at 120 minutes. Coarse and whole oat flours led to lower blood glucose and insulin, but appetite was lower after the finer flours. No differences in food intake were found. Producing coarser oat flour to add to common foods may have health benefits. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Multi-nozzle nebulisers for pressurised intraperitoneal aerosol chemotherapy (PIPAC) are implemented in clinical practice to improve the homogeneity of tissue drug delivery. Nonetheless, the advantages of such devices over one-nozzle nebulisers have not been demonstrated thus far. In this study, we compared the performance of multi- and one-nozzle nebulisers by conducting physical and ex vivo pharmacological experiments. Methods: The one-nozzle nebuliser Capnopen® and the multi-nozzle nebuliser were the subjects of this study. In physical experiments, the aerosol droplet size was measured by laser diffraction spectroscopy. Spatial spray patterns were depicted on blotting paper. Pharmacological experiments were performed on the enhanced inverted bovine urinary bladder model, demonstrating real-time tissue drug delivery, aerosol sedimentation and homogeneity of doxorubicin and cisplatin tissue distribution. Results: The multi-nozzle nebuliser had a sixfold greater aerosolisation flow and a threefold greater angle of aerosolisation than Capnopen®. The aerosol particle size and distribution range were higher than that of Capnopen®. Spray patterns on blotting paper were more extensive with the multi-nozzle nebuliser. Real-time tissue drug delivery with the multi-nozzle nebuliser was over 100 ml within 1 min, and the aerosol sedimentation was 48.9% ± 21.2%, which was not significantly different from that of Capnopen®. The doxorubicin and cisplatin tissue concentrations were greater with Capnopen®. Although there was no significant difference in the homogeneity of doxorubicin distribution between the two devices, the homogeneity of cisplatin distribution was significantly higher with Capnopen®. Conclusion: The multi-nozzle PIPAC nebuliser did not fulfil expectations. Even though the surface spray patterns were broader with the multi-nozzle nebuliser, the tissue drug homogeneity and concentration were greater with Capnopen®. [ABSTRACT FROM AUTHOR]

This systematic review explores the release and health outcomes of exposure to chalk particles in classrooms. A literature search was conducted on Scopus, Google Scholar, and the Web of Science. Chalk particles contribute significantly to poor indoor air quality in classrooms. Higher concentrations of PM2.5 chalk particles were found in the front row (14.25 µg/m3) and near the chalkboard (19.07 µg/m3). Inhalation and dermal are significant exposure routes; hence, teachers and learners are at risk of developing respiratory and skin disorders. Inhalation of chalk particles correlates with reduced lung function in teachers and learners. The release and size of chalk particles depend on the activities, type of chalk sticks, and texture of the chalkboards. Wiping the chalkboard releases more chalk particles of smaller size (3.85–9.3 µm) than writing (10.57–92.91 µm). A shift from chalk sticks and chalkboards in classrooms is necessary to mitigate the associated health risks. [ABSTRACT FROM AUTHOR]

We conducted simultaneous real-time measurements for particles on the premises of four schools, two of which were naturally ventilated (NV) and two mechanically ventilated (MV) in Kanpur, India. Health to school children from reduced particle levels inside classrooms simulated to the lowest acceptable levels (ISHRAE Class C: PM10 ≤ 100 µg/m3 & PM2.5 ≤ 25 µg/m3) using air filters were examined. Lung deposition of particles was used as a proxy for health impacts and calculated using the MPPD model. The particle levels in all classrooms were above the baseline, with NV classrooms having higher particle masses than MV classrooms: 72.16% for PM1, 74.66% for PM2.5, and 85.17% for PM10. Our calculation reveals a whooping reduction in particles deposited in the lungs (1512% for PM10 and 1485% for PM2.5) in the case of the NV classrooms. Results highlight unhealthy air inside classrooms and suggest urgent interventions, such as simple filtration techniques, to achieve acceptable levels of particles inside schools. [ABSTRACT FROM AUTHOR]

Boron doped MoSi 2 particles have been envisioned as sacrificial particles for self-healing thermal barrier coatings (TBCs) but their oxidation behaviour is yet not well understood. In this work, oxidation of MoSi 2 based particle is studied in the temperature range of 1050–1200 °C. The oxidation proceeds from a transient to a steady-state oxidation stage. The kinetics during steady-state oxidation is captured with a thermal diffusion-based model. As compared to the oxidation of pure MoSi 2 particles, the addition of boron strongly enhances the silica formation. Also, a finer dispersion of MoB x in the MoSi 2 matrix accelerates the formation of silica. The oxide growth rate constant increases proportional with the boron content of the MoSi 2 particles. This enhanced oxidation is related to the microstructure of the oxide scale. Upon oxidation, boron yields B 2 O 3 , which promptly merge with SiO 2 to form amorphous borosilicate, hindering the formation of crystalline SiO 2. Consequently, the migration of oxygen in the borosilicate oxide scale is faster than in the silica oxide scale on pure MoSi 2 particles. [ABSTRACT FROM AUTHOR]

There has been great interest in developing high‐performance, sustainable and eco‐friendly materials. This study presents an innovative development and research of the mechanical properties of dog bone–reinforced epoxy composites to determine their suitability for biomedical applications. Good surface compatibility for the matrix and reinforcement was the target, complementing the structural compatibility needed for such applications. Hand‐lay open mould technique was used to fabricate the composites with varying weight percentage of dog bone particles (DBPs), and mechanical properties (tensile strength, Young's modulus, percentage elongation and flexural strength) were determined. The results show that the developed composites' mechanical properties were enhanced, and the tensile strength of 21.10 MPa–27.97 MPa, Young's modulus of 1531.00 MPa–1732.90 MPa, ductility of 2.10%–2.60% and flexural strength of 27.53 MPa–35.67 MPa were recorded for the biocomposites. Energy‐dispersive X‐ray spectroscopy (EDS) revealed the main elements' contents of the DBPs as calcium (50.3%), carbon (20.77%) and oxygen (11.76%). Scanning electron microscopy (SEM) examination of the fractured surfaces revealed the homogeneous distribution of the dog bone particulates within the epoxy matrix, which caused the property enhancement. The findings of this research underline the potency of processed animal waste as filler materials. [ABSTRACT FROM AUTHOR]

Three different partition functions are well-known and described in statistical physics. Here, a novel partition function for the description of intra-particular interactions and with this for the mass of particles is presented below. In statistical physics, three different partition functions are already well-established. These are the microcanonical, the canonical, and the macro-canonical partition functions. Here a fourth, novel partition function is added to these already well-established three. Thereby due to the properties of quantum mechanics and superposition, this novel partition function is of fundamental different nature. According to this concept, the new partition function for particles is first defined. The masses and energies of the elementary particles are then calculated using this novel partition function. The energy of an elementary particle is proportional to the mass on the one hand and to the novel partition function on the other. The constant of proportionality with respect to the new partition function is found to be identical with Rydberg constant and Rydberg energy. The relationships found for the proton, the electron, and the sigma particle are then generalized to all elementary particles. [ABSTRACT FROM AUTHOR]

A physical description is given of the formation of corrosion product deposits on the surfaces of pipelines of heat supply systems, and an investigation has been made into the effects of various factors on this process. An analysis has been made of the existing models of formation of corrosion deposites. A mathematical model has been developed for the formation of corrosion product deposites in the liquid's motion through pipelines of heat supply systems in the region of linear velocity of the growth of deposits at a constant temperature of the heat transfer agent. The model is based on equations of conservation of the mass of dissolved depolarizer and solid particles suspended in the solution. The parametric calculations performed on the basis of the developed mathematical model have shown a possibility for the existence of a maximum in the thickness of the corrosion product deposit layer through the pipe length. [ABSTRACT FROM AUTHOR]

The present study addresses advanced monitoring techniques for particles and airborne molecular contaminants (AMCs) in cleanroom environments, which are crucial for ensuring the integrity of semiconductor manufacturing processes. We focus on quantifying particle levels and a representative AMC, hydrogen chloride (HCl), having known detrimental effects on equipment longevity, product yield, and human health. We have developed a compact laser sensor based on open-path cavity ring-down spectroscopy (CRDS) using a 1742 nm near-infrared diode laser source. The sensor enables the high-sensitivity detection of HCl through absorption by the 2-0 vibrational band with an Allan deviation of 0.15 parts per billion (ppb) over 15 min. For quantifying particle number concentrations, we examine various detection methods based on statistical analyses of Mie scattering-induced ring-down time fluctuations. We find that the ring-down distributions' 3rd and 4th standard moments allow particle detection at densities as low as ~105 m−3 (diameter > 1 μm). These findings provide a basis for the future development of compact cleanroom monitoring instrumentation for wafer-level monitoring for both AMC and particles, including mobile platforms. [ABSTRACT FROM AUTHOR]

This paper addresses the computational modeling of selective laser sintering (SLS) and 3D concrete printing (3DCP) processes in advanced manufacturing. We focus on the phenomena experienced by their feedstock materials at the level of their mesoscale (the sintering powder grain and concrete aggregate scales) during the manufacturing process. Our approach is based on the discrete element method (DEM) for representing the material's mechanical behavior. In SLS, the DEM is then combined with a lumped heat transfer model for describing the powder particles' thermal states when scanned by the laser beam. In 3DCP, in turn, the DEM is combined with the so-called discrete fresh concrete (DFC) model for representing the fresh concrete paste rheology. We then present a simple numerical solution scheme followed by numerical simulations on two model-problems, with which we illustrate the applicability of such modeling approach. [ABSTRACT FROM AUTHOR]

In this research, the finite-element numerical software COMSOL Multiphysics is used to simulate the electric pulse rock-breaking process, and the novel numerical model takes into account the multiple fields of electrical, thermal, and mechanical physics. The electric field strength inside the rock under the action of the electric pulse is updated by the full coupling function of COMSOL (version 6.1) software, and the electric damage variable χ is used to describe the process of electric breakdown inside the rock, to simulate the formation of plasma channel in the process of electric pulse rock-breaking. The voltage change curves and plasma channel trajectories in the electric breakdown process of the model in this paper are compared with the literature to verify the accuracy of the model. The formation process of plasma channels captures the temperature and stress changes during the whole process of electric pulse rock-breaking, to reveal the mechanism of the electric pulse rock-breaking process. With the presence of conductive particles inside the rock, the particles can effectively promote the formation of plasma channels, increase the area of electrical damage, and improve rock-breaking efficiency. Before the formation of the plasma channel, the internal temperature of the rock is about 600 K, and the stress is about 10−2 MPa; when the channel is formed, the energy of the electric pulse is mainly concentrated in the plasma channel, and the temperature of the plasma channel rises to 104 K. When the maximum stress exceeds the critical stress of the rock, the rock undergoes fracture. Furthermore, an appropriate increase in the rise time of the electric pulse increases the speed and area of rock-breaking, subsequently improving the efficiency of rock fracture. The results of the numerical modeling in this paper help to better understand the mechanism of the electric pulse rock-breaking process, which is of great engineering significance for the development of new electric pulse rock-breaking technology in the realm of geotechnical engineering. [ABSTRACT FROM AUTHOR]

Poetry is often described as having 'unusual syntax'. Based on a close study of nine cywydd poems by the fourteenth century Welsh poet Dafydd ap Gwilym, I identify attributive adjectives and preverbal particles as the loci of substantial departures in poetic language from the ordinary grammar of contemporary Welsh, providing an optimality theoretic analysis of the interaction between the linguistic and poetic grammars in Welsh cywyddau. I conclude that abnormally frequent noncanonical adjective ordering and omission of certain preverbal particles in poetry is a result of the domination of certain constraints on syntactic well-formedness by verse constraints. [ABSTRACT FROM AUTHOR]

Direct-on-Filter (DoF) analysis of respirable crystalline silica (RCS) by Fourier Transform Infrared (FTIR) spectroscopy is a useful tool for assessing exposure risks. With the RCS exposure limits becoming lower, it is important to characterize and reduce measurement uncertainties. This study systematically evaluated two filter types (i.e., polyvinyl chloride [PVC] and polytetrafluoroethylene [PTFE]) for RCS measurements by DoF FTIR spectroscopy, including the filter-to-filter and day-to-day variability of blank filter FTIR reference spectra, particle deposition patterns, filtration efficiencies, and pressure drops. For PVC filters sampled at a flow rate of 2.5 L/min for 8 h, the RCS limit of detection (LOD) was 7.4 μg/m3 when a designated laboratory reference filter was used to correct the absorption by the filter media. When the spectrum of the pre-sample filter (blank filter before dust sampling) was used for correction, the LOD could be up to 5.9 μg/m3. The PVC absorption increased linearly with reference filter mass, providing a means to correct the absorption differences between the pre-sample and reference filters. For PTFE, the LODs were 12 and 1.2 μg/m3 when a designated laboratory blank or the pre-sample filter spectrum was used for blank correction, respectively, indicating that using the pre-sample blank spectrum will reduce RCS quantification uncertainty. Both filter types exhibited a consistent radially symmetric deposition pattern when particles were collected using 3-piece cassettes, indicating that RCS can be quantified from a single measurement at the filter center. The most penetrating aerodynamic diameters were around 0.1 µm with filtration efficiencies ≥ 98.8% across the measured particle size range with low-pressure drops (0.2–0.3 kPa) at a flow rate of 2.5 L/min. This study concludes that either the PVC or the PTFE filters are suitable for RCS analysis by DoF FTIR, but proper methods are needed to account for the variability of blank absorption among different filters. [ABSTRACT FROM AUTHOR]

The present study was aimed at preparing stable dry adsorbed nanoparticles (DANs) of olanzapine (OLZ) loaded solid lipid nanoparticles (SLNs) for sustained release. OLZ SLNs were prepared by hot melt emulsification and ultrasonication using Precirol ATO 5 (PRE) as a solid lipid, combination of Kolliphor ELP (KELP) and Tween 80 (T80) as surfactants, after optimising formulation and process variables. The SLN system was subjected to evaluation of particle size, zeta potential, entrapment efficiency (EE), in-vitro drug release and ex-vivo intestinal permeability studies using the chicken intestinal segments (jejunum). Further, these SLNs were converted into stable DANs by adsorbing onto a Neusilin US2 (NUS2) and Avicel CL 611 (ACL) carriers using the granulation-evaporative drying method. The DANs were characterised for redispersion properties, in-vitro drug release, thermal behaviour, crystallinity, and morphology. The SLN and DAN had a particle size of 238.0 nm [0.274 polydispersity index (PdI)] and 302.4 [0.494 PdI] respectively. The zeta potentials of SLN and DAN were found to be −29.3 mV and −26.3 mV, respectively. The SLN had 67% EE, and showed a sustained drug release in various media. The highest permeability of SLNs was observed in ex-vivo permeation model compared to the OLZ suspension, indicating that SLNs have the potential to bypass hepatic metabolism. The adsorption of SLNs onto carriers was confirmed by surface morphology. The DAN had good flow properties and sustained drug release similar to that of SLNs. The X-ray diffraction (XRD) patterns and endothermic peaks confirmed the complete encapsulation of actives in lipid matrices. The encapsulating of OLZ in SLNs and converting it into DAN showed a sustained release and adsorption technique that can be used for improving the stability of NLC dispersion. The DANs can be offered in dosage forms such as filling into sachets, capsules and compressed into tablets. [ABSTRACT FROM AUTHOR]

Foods containing bits and pieces are often less liked by children; however, there is a limited understanding of how perceptions and preferences for foods with particles change during childhood. This study aimed to investigate preferences and perceptions of particle‐containing foods in children aged 5–12 years. Children (n = 485) completed a forced‐choice questionnaire on drawings of six pairs of foods, each available with or without particles. Additionally, children tasted yogurts added with muesli differing in particle size (median diameter: 3.9 or 7.5 mm) and evaluated their perception of particle size in mouth and their liking. The questionnaire results showed that children had a clear preference for foods without particles. The average probability of choosing the 'with‐particle' foods was 28%, significantly below the midpoint of 50% (p <.0001). Preferences for particle‐containing foods were lowest at age six and increased significantly with age (p =.0007). In the taste test, muesli particle size affected oral size perception (p <.0001) but not liking (p =.60). Older children were better able to differentiate particle size than younger children. However, there was no relationship between individual preferences for particle‐containing foods and oral size perception of muesli particles. The observation that children's texture preferences changed with age highlights the role of increased experience in shaping preferences for foods with particles. [ABSTRACT FROM AUTHOR]

Tunnel boring machines (TBMs) are used to excavate tunnels in a manner where the rock is constantly penetrated with rotating cutter heads. Fine particles of the rock minerals are thereby generated. Workers on and in the vicinity of the TBM are exposed to particulate matter (PM) consisting of bedrock minerals including α-quartz. Exposure to respirable α-quartz remains a concern because of the respiratory diseases associated with this exposure. The particle size distribution of PM and α-quartz is of special importance because of its influence on adverse health effects, monitoring and control strategies as well as accurate quantification of α-quartz concentrations. The major aim of our study was therefore to investigate the particle size distribution of airborne PM and α-quartz generated during tunnel excavation using TBMs in an area dominated by gneiss, a metamorphic type of rock. Sioutas cascade impactors were used to collect personal samples on 3 separate days. The impactor fractionates the dust in 5 size fractions, from 10 µm down to below 0.25 µm. The filters were weighted, and the α-quartz concentrations were quantified using X-ray diffraction (XRD) analysis and the NIOSH 7500 method on the 5 size fractions. Other minerals were determined using Rietveld refinement XRD analysis. The size and elemental composition of individual particles were investigated by scanning electron microscopy. The majority of PM mass was collected on the first 3 stages (aerodynamic diameter = 10 to 0.5 µm) of the Sioutas cascade impactor. No observable differences were found for the size distribution of the collected PM and α-quartz for the 3 sampling days nor the various work tasks. However, the α-quartz proportion varied for the 3 sampling days demonstrating a dependence on geology. The collected α-quartz consisted of more particles with sizes below 1 µm than the calibration material, which most likely affected the accuracy of the measured respirable α-quartz concentrations. This potential systematic error is important to keep in mind when analyzing α-quartz from occupational samples. Knowledge of the particle size distribution is also important for control measures, which should target particle sizes that efficiently capture the respirable α-quartz concentration. [ABSTRACT FROM AUTHOR]

On days 2023‐364 and 2024‐034, the Juno spacecraft made close passages of Jupiter's moon Io, at altitudes of about 1,500 km. Data obtained from the first flyby, when the spacecraft was on magnetic field lines connected to both Jupiter and Io, revealed deep flux decreases. In addition, Juno's energetic particle detectors observed tens to hundreds of keV electron and proton beams. Such beams could be generated near Jupiter on field lines associated with Io. The second encounter occurred in the plasma wake and a more modest flux decrease was observed. Furthermore, data from both encounters suggest a spatially extensive decrease in >1 MeV electrons that includes regions inward of Io's orbit. In the immediate vicinity of Io, signatures of absorption likely dominate the data whereas diffusion and wave‐particle interactions are expected to be needed to understand MeV electron data in the wider spatial region around Io. Plain Language Summary: Jupiter's magnetospheric plasma overtakes Io in its orbit. This causes a cavity to be formed over the hemisphere of Io that leads its orbital motion. Within this cavity subtle details of the plasma and energetic charged particle environment can be extracted from the signal, usually dominated by radiation at these distances. Examples include beams traveling in the direction from Jupiter to the moon, with little evidence of reflection at Io. Another major finding of this work is that there is a large region both along Io's orbit and even radially inward of it with a lower level of MeV electron flux. Guided by previous modeling, the most likely candidates for shaping the data are absorption by the moon, wave‐particle interactions that can scatter particles into Jupiter's atmosphere, and diffusion. Key Points: Deep flux decreases over Io and in its immediate wake caused by losses to the moon's surface were observed in Juno JEDI dataJuno JEDI detected narrow field‐aligned beams of electrons and protons directed toward Io's north poleMoon absorption and wave‐particle interactions may explain the loss of >1 MeV electrons that extend both inward and outward of Io's orbit [ABSTRACT FROM AUTHOR]

A method was developed to analytically distinguish between the ventilated (v) and nonventilated (nv) fractions of water‐soluble ions in deposits of particle indoors. The indicative method was based on low‐cost passive outdoor and indoor sampling of the particle and ion deposits and NO2 gas and analysis of the regression values and residuals of the correlations between these parameters. The method was applied to measurements in the Pieskowa Skała Castle Museum in Poland. A dominating source of "soil and building dust" was indicated all year round, probably partly from renovation works of the castle, with larger total infiltration in the winter–spring (W‐S) but with a higher proportion of ventilation ingress in the summer–autumn (S‐A). About 60%–80%, by mass, of the water‐soluble ions in the soil and building dust were calcium and probably some magnesium bicarbonate (Ca(HCO3)2, Mg(HCO3)2) and about 10%–20% sulfates (SO4−−) with calcium (Ca++) and several other cations. The other main source of the ion deposits was indicated to be air pollution, with chloride (Cl−), sulfate (SO4−−), and nitrate (NO3−), from outdoor combustion sources, like traffic, residential heating, and industry. These were mainly v from outdoors in the colder parts of the year, but also to the more open locations in the S‐A. A small source of nv sulfate (SO4−−) was identified inside two showcases in the S‐A. The study showed good enclosure protection of the museum objects against exposure to particle pollution, but also the need to avoid the trapping of particle pollution inside showcases or closed rooms. The identification of the probable different amounts and sources of v and nv ions in the castle aided preventive actions to reduce the pollution exposure. [ABSTRACT FROM AUTHOR]

Due to climate change, wildfires have increased in intensity and duration. While wildfires threaten lives directly, the smoke has more far-reaching adverse health impacts. During an extreme 2017 wildfire event, residents of Seeley Lake, Montana were exposed to unusually high levels of wood smoke (WS) causing sustained effects on lung function (decreased FEV1/FVC). Objective: The present study utilized an animal model of WS exposure to research cellular and molecular mechanisms of the resulting health effects. Methods: Mice were exposed to inhaled WS utilizing locally harvested wood to recapitulate community exposures. WS was generated at a rate resulting in a 5 mg/m3 PM2.5 exposure for five days. Results: This exposure resulted in a similar 0.28 mg/m2 particle deposition (lung surface area) in mice that was calculated for human exposure. As with the community observations, there was a significant effect on lung function, increased resistance, and decreased compliance, that was more pronounced in males at an extended (2 months) timepoint and males were more affected than females: ex vivo assays illustrated changes to alveolar macrophage functions (increased TNFα secretion and decreased efferocytosis). Female mice had significantly elevated IL-33 levels in lungs, however, pretreatment of male mice with IL-33 resulted in an abrogation of the observed WS effects, suggesting a dose-dependent role of IL-33. Additionally, there were greater immunotoxic effects in male mice. Discussion: These findings replicated the outcomes in humans and suggest that IL-33 is involved in a mechanism of the adverse effects of WS exposures that inform on potential sex differences. [ABSTRACT FROM AUTHOR]

A numerical simulation of the gasdynamic processes accompanying the formation and propagation of vortex rings obtained with the use of a piston-type generator has been performed. The formation of a vortex ring, the capture of particles of a disperse admixture by it, and their carry by the ring are considered. The numerical calculations were conducted with the use of nonstationary Navier–Stokes equations, and the movement of particles was defined using the discrete-trajectory method. The distribution of the admixture particles in a vortex ring was determined depending on the conditions of its formation. The influence of the characteristics of a vortex ring on the carry of a passive admixture by it was investigated. The reasons for the qualitative and quantitative differences between the losses of particles in a vortex ring in the path of its movement in different regimes are discussed. [ABSTRACT FROM AUTHOR]

In West African cities, the impacts of the air quality on the health of the population is expected to increase significantly in the near future. For the first time to our knowledge, we conducted a high-resolution modeling study over Abidjan (Côte d'Ivoire) using the WRF-Chem model and the simplified GOCART model to simulate carbonaceous aerosols BC and OC, sulfate, dust, sea salt, PM2.5, and PM10. The simulations were carried out during January and February 2019, a period over which there are databases of observations available. The DACCIWA inventory provided anthropogenic emissions at the regional scale, whereas a new emission inventory has been developed for the city of Abidjan. In 2019, the emissions were 4986.8 Gg for BC, 14,731.4 Gg for OC, and 7751.6 Gg for SO2. Domestic fires were the primary OC source (7719.5 Gg), while road traffic was the largest BC emitter (2198.8 Gg). Our modeling results generally overestimate urban particle concentrations, despite having a better agreement for those based on the inventory of the city of Abidjan. Modeled concentrations of BC are higher in administrative centers due to road traffic, while OC concentrations are significant in densely populated neighborhoods. [ABSTRACT FROM AUTHOR]

In the present study, magnesium nanoparticles (Mg NPs) were synthesized utilizing an aqueous extract of Berberis aristate rhizome and evaluated for antimicrobial and anti-inflammatory activity. Technofunctional properties of rhizome powder were evaluated and during thermal stability evaluation four stages of decomposition with a maximum delta Y value of 76.04 % was observed. Optimization of Mg NPs was carried out by employing eight different concentrations (C1-C8) and the C4 showed maximum absorbance at 330 nm confirming the NPs synthesis. The Mg NPs showed the particle size of 62 nm, zeta potential of −24.7 mV and hexagonal mprphology. Potential inhibition against S. aureus and E. coli (76.78 ± 0.05% and 74.62 ± 0.17%)and anti-inflammatory activity ranging from 42.43 ± 0.07–82.92 ± 0.04% was observed for Mg NPs. Therefore, green synthesis of Mg NPs is a promising approach for the development ofbiological active NPs to cure microbial infections. [ABSTRACT FROM AUTHOR]

Ultrasonic wave propagates with strong penetration, high stability, and has non-contact nature, therefore it is widely used in the petroleum industry. As an application example, an ultrasonic flowmeter can accurately measure the annular flow rate of water-based drilling fluid. According to the outlet flow rate, it can be noticed if there is an abnormal situation in the well to avoid accidents such as well kick and blowout. However, due to the attenuation of ultrasonic wave in the drilling fluid, the relevant research results are not reliable. Herein, based on the theory of acoustics, the influences of water-based drilling fluid density, solid particle size and solid particle number on the ultrasonic attenuation characteristics under different frequencies are studied by numerical simulation. First, the propagation characteristics of ultrasonic wave in water-based drilling fluid are systematically analyzed, then the accuracy of the above results is verified by laboratory tests. The results show that the ultrasonic attenuation rate is positively correlated with the solid particle size, solid particle number and ultrasonic frequency in water-based drilling fluid, while it is negatively correlated with the density of water-based drilling fluid. Furthermore, it is established that the ultrasonic energy decreases with increasing propagation distance. The results of this study can provide a theoretical basis and practical guidance for using an ultrasonic flowmeter to accurately measure the annulus return flow rate of drilling fluid and develop an intelligent drilling system, so as to improve the efficiency of field operation and drilling success rate. [ABSTRACT FROM AUTHOR]

In this research, we sought to establish whether adult non-native English speakers interpret aspectual phrasal verbs by means of the continuous or discontinuous position of the particle that goes with them and whether this is related to their level of proficiency in English as a second language (L2). An image selection task was designed and applied to adult native and non-native English speakers, the latter were divided into four groups based on their hours of exposure to the target language (100–200 h, 300–400 h, 600–700 h, +1000 h.). The results obtained suggest that the position of the particle can sometimes affect the interpretation of phrasal verbs of English by non-native speakers; however, this does not occur in the same way for all phrasal verbs, since the interpretation is also linked to the category to which they belong and to the particle present in each case. Finally, non-native speakers of English with a greater number of hours of exposure to the target language do not have a significantly different performance from non-native speakers when interpreting phrasal verbs, although in some cases the differences are pronounced. [ABSTRACT FROM AUTHOR]

Background: Tendon stem/progenitor cell (TSPC) senescence contributes to tendon degeneration and impaired tendon repair, resulting in age-related tendon disorders. Ferroptosis, a unique iron-dependent form of programmed cell death, might participate in the process of senescence. However, whether ferroptosis plays a role in TSPC senescence and tendon regeneration remains unclear. Recent studies reported that Platelet-derived exosomes (PL-Exos) might provide significant advantages in musculoskeletal regeneration and inflammation regulation. The effects and mechanism of PL-Exos on TSPC senescence and tendon regeneration are worthy of further study. Methods: Herein, we examined the role of ferroptosis in the pathogenesis of TSPC senescence. PL-Exos were isolated and determined by TEM, particle size analysis, western blot and mass spectrometry identification. We investigated the function and underlying mechanisms of PL-Exos in TSPC senescence and ferroptosis via western blot, real-time quantitative polymerase chain reaction, and immunofluorescence analysis in vitro. Tendon regeneration was evaluated by HE staining, Safranin-O staining, and biomechanical tests in a rotator cuff tear model in rats. Results: We discovered that ferroptosis was involved in senescent TSPCs. Furthermore, PL-Exos mitigated the aging phenotypes and ferroptosis of TSPCs induced by t-BHP and preserved their proliferation and tenogenic capacity. The in vivo animal results indicated that PL-Exos improved tendon-bone healing properties and mechanical strength. Mechanistically, PL-Exos activated AMPK phosphorylation and the downstream nuclear factor erythroid 2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPX4) signaling pathway, leading to the suppression of lipid peroxidation. AMPK inhibition or GPX4 inhibition blocked the protective effect of PL-Exos against t-BHP-induced ferroptosis and senescence. Conclusion: In conclusion, ferroptosis might play a crucial role in TSPC aging. AMPK/Nrf2/GPX4 activation by PL-Exos was found to inhibit ferroptosis, consequently leading to the suppression of senescence in TSPCs. Our results provided new theoretical evidence for the potential application of PL-Exos to restrain tendon degeneration and promote tendon regeneration. [ABSTRACT FROM AUTHOR]

The complex air environment makes it urgent to build good and safe indoor environments, and the study and application of new materials have become the focus of current research. In this study, we tested and analyzed the structural parameters and filtration performances of the four most commonly used new filter materials in the current market. The results showed that all four new filter materials showed a trend of first increasing and then decreasing their filtration efficiency with an increase in filtration velocity. The filtration efficiency of the materials was as follows: PTFE > glass fiber > nanomaterial > electret. The filtration efficiency of all materials reached its maximum when the filtration velocity was 0.2 m/s. The filtration efficiency of the PTFE for PM10, PM2.5, and PM1.0 was higher than that of the other three materials, with values of 0.87% to 24.93%, 1.21% to 18.69%, and 0.56% to 16.03%, respectively. PTFE was more effective in capturing particles smaller than 1.0 μm. Within the testing velocity range, the resistance of the filter materials was as follows: glass fiber > PTFE > electret > nanomaterial, and the resistance of the four materials showed a good fitting effect. It is also necessary to match the resistance with the filtration efficiency during use, as well as to study the effectiveness of filter materials in blocking microorganisms and absorbing toxic gases. Overall, PTFE showed the best comprehensive performance, as well as providing data support for the selection of related materials or the synthesis and research of filter materials in the future. [ABSTRACT FROM AUTHOR]

Higher concentrations of air pollutants, such as nitrogen dioxide (NO 2 ) and particulate matter (PM), are observed in streets compared to the urban background. These concentrations could be predominantly attributed to road traffic, which remains an important source despite relentless efforts. In this study, performed over the Paris area, the impacts of the evolution of the fleet composition on urban air quality down to the street scale is assessed with two scenarios assuming the introduction of very-low-emission vehicles. Exhaust emission factors for these vehicles are based on the improvement of engine and after-treatment technologies, leading to factors lower than those proposed for the European emission standard Euro 7. Using the year 2014 as the baseline, very-low-emission vehicles are introduced up to the year 2030 for the Paris region. NO 2 emissions are thus reduced by 68 % in streets, and concentrations by 53 %. However, PM concentration reduction is limited to 18 % in streets as non-exhaust emissions from tyre and brake wear and road abrasion are preponderant. PM emissions from non-exhaust sources represent 59 % of the total road-traffic emission of PM in 2014 and 89 % in 2030. Non-regulated pollutant concentrations are also reduced, by 42 % for black carbon and 30 % for organic matter. Considering only very-low-emission and electric vehicles in the fleet further reduce NO 2 emissions and concentrations by 99.5 % and 80 % respectively. PM concentrations are only reduced by 22 %. This study highlights the high reduction potential of NO 2 concentrations with very-low-emission and electric vehicles, because of reduction of exhaust emissions. However, difficulties remain to reduce PM concentrations in urban areas, with the large majority of PM traffic emissions coming from non-exhaust sources. [ABSTRACT FROM AUTHOR]

Plastic materials are used in various domains, such as constructions, textile, or medical applications, due to their durability and versatility. Despite plastics contribution to human wellbeing, these materials can also have a negative impact on ecosystems, leading to water pollution and loss of aquatic life. However, no study has been made, so far, to determine the impact of plastic products on natural particle size distribution in water systems. The aim of this study is to evaluate if plastic affects aquatic particulate matter of different size ranges, from 0.3 to 16 000 nm. Three types of plastics (polystyrene [PS], polypropylene [PP], and low‐density polyethylene [LDPE]) have been added to lake water samples and incubated for nine months at room temperature. Results show that the average particle size increases toward the end of the experiment indicating that small particles (<1200 nm) adhere to plastic surfaces, while medium and large particles sediment in the water sample. Also, substances migrating from plastic may alter the aggregating properties of particles. However, the influence may be less substantial in the environment, as plastic types and concentrations differ. Moreover, more studies are needed to establish additional implications in relation to bacterial communities, transport of pollutants, or chemical composition. [ABSTRACT FROM AUTHOR]

The effect of removing suction on energy consumption, displacement, and separation of particles with different sizes and densities in the jig was investigated by CFD-DEM coupling. Water velocity functions were categorized into four modes: normal sinusoidal, partial removal of suction, complete removal of suction, and optimal. Particles rise to a certain height in the normal sinusoidal mode, while their jump height increases in the case of partial or complete removal of suction. The jump was controlled by fluid and added (Hutch) water velocities. Increasing the maximum jump height of particles leads to a decrease in separation, an increase in operational costs, and heightened particle mixing and energy consumption. In both modes of partial or complete suction removal, the fluid velocity should be reduced. The extent of velocity reduction depends on the power required to move the particles. The simulation of coarse particles (7 and 8 mm) revealed that in the complete removal of suction, the velocity should be decreased to less than half of the normal sinusoidal mode, and the hutch water velocity should be equivalent to the velocity amplitude. The energy consumption for the optimal mode was significantly lower than that of the other modes. [ABSTRACT FROM AUTHOR]

In multiphase particulate systems, the turbulence of the continuous phase (gas or liquid) is modulated due to interactions between the continuous phase and the suspended particles. Such phenomena are non-trivial in the essence that addition of a dispersed phase to a turbulent flow complicates the existing flow patterns depending on the physical properties of the particles leading to either augmentation or attenuation of continuous phase turbulence. In the present study, this aspect has been comprehensively analysed based on the available experimental data obtained from the well-studied turbulent flow systems such as channel and pipes, free jets and grids. Relevant non-dimensional parameters such as particle diameter to integral length scale ratio, Stokes number, particle volume fraction, particle momentum number, and particle Reynolds number have been utilised to characterise the reported turbulence modulation behavior. Some limitations of these commonly used dimensionless parameters to characterise turbulence modulation are discussed, and possible improvements are suggested. [ABSTRACT FROM AUTHOR]

Sufficient homogeneity of the certified parameter(s) over the whole fill series of a matrix reference material (RM) is a fundamental quality criterion. In practice, the heterogeneity of the target parameter is evaluated, whereby a relative value can be calculated of how much the target parameter is varying over the RM-batch. A high degree of homogeneity (low heterogeneity) is an inherent quality mark of a good RM. Here, we report how challenging matrix RMs were produced by using particle suspensions at the core of the material processing step. The examples of matrix RMs produced span from whole water reference materials for persistent organic pollutants, PM2.5-like atmospheric dust certified for specific ions to microplastic RMs. Most of these RMs were subsequently used in different phases of analytical method development or for method validation. Common to all these matrices is that they cannot be easily mixed, handled, or dosed to prepare larger sample batches. In all cases, a continuously stirred suspension of particles was used during material processing. In general, relative between-bottle heterogeneities from 1.6 to 6% were achieved for the target parameters in these matrix presentations. Concerning developments of new CRMs in emerging fields, the co-dependence between the availability of validated analytical methods with good repeatability and testing materials with a known and high homogeneity of the target parameter(s) becomes particularly challenging. This situation is an RM/Method causality dilemma. To overcome that hurdle, strategies are proposed for stepwise processes where RM producers and a network of analytical method developers could work hand in hand. In addition, development of a portfolio of inexpensive and well-homogenised common samples coupled with a reporting interface is suggested. This would benefit method developers and RM producers alike. As more and more data is compiled for a specific matrix, it paves the way for new and challenging RMs that can later be used by a wider community. [ABSTRACT FROM AUTHOR]

This work introduces the mobile app ContLab with advanced computational code installed on mobile devices (tablet, cellphone, iPad, etc.), with internet access, and compatible with Android operating systems. It is designed to be coupled with a simple microscope for the automated counting of particles, ranging in size from 0.05 µm to 50 µm, within the microfiltration spectrum, and specifically customized for micelle counting produced in fermentable processes. It is an easily accessible and cost-effective device for users interested in micelle counting present in any fermentable broth, such as in the pharmaceutical, food, and brewing industries. The app enhances the speed and precision of results compared to the manual counting method. [ABSTRACT FROM AUTHOR]

The results of experimental studies of the erosion rate of high-purity tungsten cathodes after pulsed arc discharges in a pure oil-free ultrahigh vacuum and in gases of various purities are reported. The erosion rate in high-purity argon does not change compared to the rate of erosion of electrodes in a pure oil-free vacuum. The rate of erosion in "technical" argon is 10–20% less than the rate of erosion of electrodes in an oil-free vacuum. The rate of erosion in "technical" nitrogen is 15–35% less than the rate of erosion of electrodes in vacuum. Particle sizes formed in gas arcs are smaller than those formed in vacuum arcs. [ABSTRACT FROM AUTHOR]

Objective: To explore the protective effect of human urine‐derived stem cell exosomes (hUSC‐Exos) on radiation‐induced salivary gland (SG) injuries in Sprague Dawley rats. Methods: Fresh adult urine was collected, and primary hUSCs were isolated and identified. The hUSCs were hypoxia‐pretreated with 1% oxygen for 24 h and then transferred to a normoxic culture environment for 24 h. The hUSC‐Exos were collected and identified for exosomes. A radiation‐induced injury model was established in the rats, and exosomes were introduced by local injection in the SG and tail vein. The submandibular gland was excised for morphological observation 1 week later. Immunohistochemical detection of the glandular tissue was conducted by α‐smooth muscle actin (a‐SMA), stem cell growth factor receptor (c‐Kit) staining, and periodic acid–Schiff staining. Qualitative polymerase chain reaction and western blot analysis were adopted to detect the gene and protein expression of Wnt3a, GSK3β, and Axin. Results: In both the normoxic and hypoxic hUSC‐Exo groups, microvesicular structures with bilayer membranes of approximately 80 nm in diameter were detected, and the expressions of CD9 and CD63 were detected by nanoflow cytometry. Compared with the control group, in the radiation‐induced injury model group, the expression of a‐SMA was significantly higher, the expression of c‐Kit was significantly lower, and the expressions of Wnt3a, GSK3β, and Axin were significantly upregulated; the differences were statistically significant (p < 0.05). Compared with the model group, in the normoxic and hypoxic hUSC‐Exo groups, the expression of a‐SMA was significantly decreased, the expression of c‐Kit was significantly increased, and the expressions of Wnt3a, GSK3β, and Axin were significantly upregulated; the differences were statistically significant (p < 0.05). Conclusion: Hypoxia‐pretreated hUSC‐Exos could repair radiation‐induced SG injuries by activating the Wnt3a/GSK3β pathway to suppress the expressions of a‐SMA and c‐Kit. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to quantitatively investigate airborne particle load in the operating room during endoscopic or microscopic epitympanectomy or mastoidectomy. Method: In the transcanal endoscopic ear surgery group, drilling was performed underwater. A particle counter was used to measure the particle load before, during and after drilling during transcanal endoscopic ear surgery or microscopic ear surgery. The device counted the numbers of airborne particles of 0.3, 0.5 or 1.0 μm in diameter. Results: The particle load during drilling was significantly higher in the microscopic ear surgery group (n = 5) than in the transcanal endoscopic ear surgery group (n = 11) for all particle sizes (p < 0.01). In the transcanal endoscopic ear surgery group, no significant differences among the particle load observed before, during and after drilling were seen for any of the particle sizes. Conclusion: Bone dissection carries a lower risk of airborne infection if it is performed using the endoscopic underwater drilling technique. [ABSTRACT FROM AUTHOR]

Objectives: The superiority and usefulness of liquid material over particles for embolization have been a topic of debate due to differences in materials and techniques. This study aimed to identify the complications and outcomes associated with both embolization materials. Methods: This retrospective multicenter cohort study included 93 patients from an endovascular treatment registry, treated from January 1, 2018 to May 31, 2022. It included patients who underwent preoperative embolization for meningioma, solitary fibrous tumor/hemangiopericytoma, and hemangioblastoma. Data for patient characteristics, procedural factors, complications, and outcomes were collected from medical records. Results: A tortuous access route was the only factor independently associated with complications (p = 0.020). Although liquid material was more frequently used for embolization in relatively high-risk conditions, complication rates did not differ significantly between the groups (p = 0.999). In the liquid material group, the tip of the microcatheter could be guided closer to the tumor (p <0.001) using a distal access catheter and flow-guide microcatheters. The subgroup middle meningeal artery embolization had less operative bleeding in the liquid material group (p <0.001), whereas the particles group exhibited less intraoperative blood loss than the liquid material group (p = 0.006). Conclusion: The vascular tortuosity of the access route was only associated with complications in preoperative tumor embolization. Liquid material and particles showed no difference in complication rates. The use of particles in embolization may reduce intraoperative bleeding, but not in all cases can it be used safely. Therefore, a thorough understanding of the characteristics of both approaches and their relative advantages in clinical practice is essential to opt for the appropriate material according to the case. [ABSTRACT FROM AUTHOR]