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BACKGROUND: Chronic exposure to microorganisms inside homes can impact respiratory health. Few studies have used advanced sequencing methods to examine adult respiratory outcomes, especially continuous measures. We aimed to identify metagenomic profiles in house dust related to the quantitative traits of pulmonary function and airway inflammation in adults. Microbial communities, 1264 species (389 genera), in vacuumed bedroom dust from 779 homes in a US cohort were characterized by whole metagenome shotgun sequencing. We examined two overall microbial diversity measures: richness (the number of individual microbial species) and Shannon index (reflecting both richness and relative abundance). To identify specific differentially abundant genera, we applied the Lasso estimator with high-dimensional inference methods, a novel framework for analyzing microbiome data in relation to continuous traits after accounting for all taxa examined together. RESULTS: Pulmonary function measures (forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio) were not associated with overall dust microbial diversity. However, many individual microbial genera were differentially abundant (p-value < 0.05 controlling for all other microbial taxa examined) in relation to FEV1, FVC, or FEV1/FVC. Similarly, fractional exhaled nitric oxide (FeNO), a marker of airway inflammation, was unrelated to overall microbial diversity but associated with differential abundance for many individual genera. Several genera, including Limosilactobacillus, were associated with a pulmonary function measure and FeNO, while others, including Moraxella to FEV1/FVC and Stenotrophomonas to FeNO, were associated with a single trait. CONCLUSIONS: Using state-of-the-art metagenomic sequencing, we identified specific microorganisms in indoor dust related to pulmonary function and airway inflammation. Some were previously associated with respiratory conditions; others were novel, suggesting specific environmental microbial components contribute to various respiratory outcomes. The methods used are applicable to studying microbiome in relation to other continuous outcomes. Video Abstract.

We report state-of-the-art first-principles molecular dynamics results on the heterogeneous chemical uptake of NO2, a major anthropogenic pollutant, on the dry and wet hydroxylated surface of α-quartz, which is a significant component of silica-based catalysts and atmospheric dust aerosols. Our investigation spotlights an unexpected chemical pathway by which NO2 (i) can be adsorbed as HONO by deprotonation of interfacial silanols (i.e., –Si–OH group) on silica, (ii) can be barrierless converted to nitric acid, and (iii) can finally dissociated to surface bounded NO and hydroxyl gas phase radicals. This chemical pathway does not invoke any previously experimentally postulated NO2 dimerization, dimerization that is less likely to occur at low NO2 concentrations. Moreover, water significantly catalyzes the HONO formation and the dissociation of nitric acid into surface-bounded NO and OH radicals, while visible light adsorption can further promote these chemical transformations. This work highlights how water-restricted solvation regimes on common mineral substrates are likely to be a source of reactive oxygen species, and it offers a theoretical framework for further and desirable experimental efforts, aiming to better constrain trace gases/mineral interactions at different relative humidity conditions. [ABSTRACT FROM AUTHOR]

Thirdhand smoke (THS) is the persistent and toxic residue from tobacco smoke in indoor environments. A comprehensive understanding of the chemical constituents of THS is necessary to assess the risks of long-term exposure and to establish reliable THS tracers. The objective of this study was to investigate compounds associated with THS through nontargeted analysis (NTA) of settled house dust samples from smokers' and non-smokers' homes, using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS). Compounds that were either only present in dust from smokers' homes or that had significantly larger abundance than in non-smokers' homes were termed qualified compounds. We identified 140 qualified compounds, and of these, 42 compounds were tentatively identified by searching matching mass spectra in NIST electron impact (EI) mass spectral library including 20 compounds confirmed with their authentic standards. Among the 42 compounds, 26 compounds were statistically more abundant (p

BackgroundPrior studies suggested that air pollution exposure may increase the risk of Parkinson's Disease (PD). We investigated the long-term impacts of traffic-related and multiple sources of particulate air pollution on PD in central California.MethodsOur case-control analysis included 761 PD patients and 910 population controls. We assessed exposure at residential and occupational locations from 1981 to 2016, estimating annual average carbon monoxide (CO) concentrations - a traffic pollution marker - based on the California Line Source Dispersion Model, version 4. Additionally, particulate matter (PM2.5) concentrations were based on a nationwide geospatial chemical transport model. Exposures were assessed as 10-year averages with a 5-year lag time prior to a PD diagnosis for cases and an interview date for controls, subsequently categorized into tertiles. Logistic regression models were used, adjusting for various factors.ResultsTraffic-related CO was associated with an increased odds ratio for PD at residences (OR for T3 vs. T1: 1.58; 95% CI: 1.20, 2.10; p-trend = 0.02) and workplaces (OR for T3 vs. T1: 1.91; 95% CI: 1.22, 3.00; p-trend

Detection sensitivity of aquatic species using environmental DNA (eDNA) generally decreases in turbid water but is poorly characterized. In this study, eDNA detection targeted delta smelt (Hypomesus transpacificus), a critically endangered estuarine fish associated with turbid water. eDNA sampling in the field was first paired with a trawl survey. Species-specific detection using a Taqman qPCR assay showed concordance between the methods, but a weak eDNA signal. Informed by the results of field sampling, an experiment was designed to assess how turbidity and filtration methods influence detection of a rare target. Water from non-turbid (5 NTU) and turbid (50 NTU) estuarine sites was spiked with small volumes (0.5 and 1 mL) of water from a delta smelt tank to generate low eDNA concentrations. Samples were filtered using four filter types: cartridge filters (pore size 0.45 μm) and 47 mm filters (glass fiber, pore size 1.6 μm and polycarbonate, pore sizes 5 and 10 μm). Prefiltration was also tested as an addition to the filtration protocol for turbid water samples. eDNA copy numbers were analyzed using a censored data method for qPCR data. The assay limits and lack of PCR inhibition indicated an optimized assay. Glass fiber filters yielded the highest detection rates and eDNA copies in non-turbid and turbid water. Prefiltration improved detection in turbid water only when used with cartridge and polycarbonate filters. Statistical analysis identified turbidity as a significant effect on detection probability and eDNA copies detected; filter type and an interaction between filter type and prefilter were significant effects on eDNA copies detected, suggesting that particulate-filter interactions can affect detection sensitivity. Pilot experiments and transparent criteria for positive detection could improve eDNA surveys of rare species in turbid environments.

General Relativity describes the trajectories of light-rays through curved spacetime near a massive object. In addition to gravitational lensing, we include an absorbing dielectric medium given by a complex refractive index known as the Drude model. When absorption is included the eikonal becomes complex, with the imaginary part related to the absorption along a ray between emission and observation points. We extend results from the literature to include dispersion in the index of refraction. The complex Hamiltonian splits into a real part that describes the equations of motion and a constraint equation that governs the momentum loss in the system. We work in coordinates which are fully real, with a real metric in physical spacetime. We assume the dust and plasma distributions of the Drude matter to coincide and vary as a power-law 1 / r h . We find that transmission requires h > 1, otherwise exponential absorption occurs along ray paths. We use ray-tracing through strongly absorbing matter near the surface of the compact star, as well as specializing to a point-lens in the weak-field limit with weakly absorbing matter to generate potentially observable light curves for distant observers. In the appropriate limits, our theory reproduces results from the literature. [ABSTRACT FROM AUTHOR]

This article introduces the notions of asymptotic dust and asymptotic radiation equations of state. With these non-linear generalizations of the well known dust or (incoherent) radiation equations of state the perfect-fluid equations lose any conformal covariance or privilege. We analyse the conformal field equations induced with these equations of state. It is shown that the Einstein- λ -perfect-fluid equations with an asymptotic radiation equation of state allow for large sets of Cauchy data that develop into solutions which admit smooth conformal boundaries in the future and smooth extensions beyond. In the case of asymptotic dust equations of state sharp results on the future asymptotic behaviour are not available yet. [ABSTRACT FROM AUTHOR]

This study examined the heavy metal content in dust storm samples from Erbil, Iraq, along with four other locations. Using ICP-MS, Cd, Ni, Cr, Hg, Pb, Zn, Mn, Cu, Co, Fe and As were determined. The health risks due to exposure to these metals through ingestion, inhalation and dermal contact were assessed for both adults and children. Non-carcinogenic risks were evaluated using the hazard quotient (HQ) and hazard index (HI). Children faced a cumulative risk with HQ > 0.2 for As and Cr and HI > 1. The carcinogenic risk was measured using the carcinogenic risk factor (CRF), which fell below 10–6, indicating low cancer risk. However, children had a higher cancer risk (10−4 to 10−6) for As. The pollution indices revealed varying pollution levels from unpolluted to moderately polluted in the studied areas. Overall, this study highlights potential health risks associated with heavy metal exposure during dust storms, particularly for children, and emphasises the importance of addressing these concerns to safeguard public health. [ABSTRACT FROM AUTHOR]

Particles regularly tribocharge in collisions. Here, we study how long charges can persist on such particles in the environment of a protoplanetary disc. We set up three complementary experiments to quantify discharge time-scales. We first directly measure the time dependency of charge on triboelectrically charged objects. For this aspect, we performed two long-time experiments under different environmental conditions. We find that the charge persists on the tribocharged bodies on time-scales between minutes and years. Discharge might be mediated by external ions or internally, by conduction. To constrain the latter, we also determined the specific electric resistance of dust samples as simulants for dust aggregates in protoplanetary discs. In this third experiment, we see an increase in resistivity at decreasing ambient pressure up to the limit of the instrument. These findings are consistent with the assumption that water on all relevant surfaces including dust grains within the pore space of aggregates is the main driver of discharge. Under disc conditions, the charge might persist for weeks to years. This leaves net-charged isolated grains in dense parts of the mid-plane of protoplanetary discs charged in between collisions. [ABSTRACT FROM AUTHOR]

Snow cover is an important source of data for the study of environmental pollution due to its ability to accumulate atmospheric dust particles. A total reflection x‐ray fluorescence method (TXRF) was applied to assess the concentration levels of potentially toxic elements (As, Pb, Zn, Ni, Cu, Cr, V, Mn, and Sr) in samples of snow cover solid phase collected in suburban areas of the Irkutsk region with industrial activity. Suspension was chosen as an optimal sample preparation procedure for solid phases of snow samples obtained after melting and filtration. Results were compared with those obtained by wavelength‐dispersive x‐ray fluorescence spectrometry and atomic absorption spectrometry. Precision of TXRF results expressed by repeatability values was not exceeded 15% (n = 3) for most of the elements, and the trueness of the TXRF method expressed by recovery values was in the range of 87%–115% for concentration levels of 5.0–350 μg/g. Forty samples of snow cover solid phase were analyzed by TXRF method and results were compared with the background values. The investigation showed low contamination of the studied area by Pb, Cu, V, Mn, and Sr, medium contamination by Ni, As, and Cr, and high contamination by Zn. TXRF is advantageous in being rapid, cost‐efficient, and simple and can be used as a promising method for an assessment of environmental pollution. [ABSTRACT FROM AUTHOR]

The valuable metals copper and zinc were successfully recovered from a water-quenched lead smelting slag containing zinc in Gansu Province. This study focuses on the application of the direct reduction roasting-flotation process for extracting these metals from the slag phase. To comprehend the recovery principle of copper and zinc minerals in the slag phase, various techniques including thermodynamic analysis, scanning electron microscopy, energy dispersive spectrometry, and mineral liberation analyzer were employed. The findings demonstrate that zinc minerals can be easily recovered through reduction roasting processes. Following roasting, chalcopyrite within the slag phase recrystallizes into larger particles which become exposed on the surface of vitreous gangue material. By optimizing parameters such as roasting time (90 min), coke dosage (12.5%), and roasting temperature (1250°C), a remarkable volatilization rate of 99.27% for zinc in the slag phase was achieved while successfully recovering high-purity zinc oxide dust. Copper ores undergo a transition from being difficult to dissociate into monomers to becoming easier to dissociate, thereby enhancing their flotation recovery potential. Through one rough flotation followed by three cleaning flotation during process, a concentrate with an impressive copper grade of 18.24% and copper recovery rate of 56.22% was obtained. [ABSTRACT FROM AUTHOR]

Air pollution as a result of desertification and dust transportation is one of the critical environmental challenges in the arid and semi-arid regions. Urmia Lake, the largest inland lake of Iran has lost most of its water over the past 2 decades. The lake bed is known as one of the aerosol pollution sources in the northwestern Iran. Although recent studies contributed to investigate the impacts of the drying up of Urmia Lake on the local and regional air quality, there is still a need to identify spatiotemporal aerosol pollution and dust generation sources in the study area. In this study, remote sensing techniques, fuzzy logic and Principal Component Analysis (PCA) were used to identify dust hot spots in the south and east parts of the Lake, where recent studies have highlighted the dramatic extent of salinization and desertification. Based on the results of this study, the lake's contribution to the local aerosol pollution declines with increasing distance from it. The results indicated that the potential of dust forming on the east side of the lake has increased, presenting a variety of challenges for inhabitants, including health and biological hazards. The fuzzy results have a high correlation with Electrical Conductivity (EC) (0.69), Aerosol Optical Depth (AOD) (0.46), and Leaf Area Index (0.45), respectively, while wind speed (0.22) and slope (0.24) have the lower correlation. The results of PCA indicate that AOD, Digital Elevation Model, and EC have the highest percentage in identifying dust generation sources among the effective parameters in determining dust production sources. [ABSTRACT FROM AUTHOR]

Mercury (Hg) pollution around artisanal and small-scale gold mining (ASGM) areas has been of much concern. Many studies have reported elevated Hg concentrations in environmental media, but studies on dust relating to inhalation exposure of Hg around ASGM area are limited. In this study, we investigated Hg in indoor and outdoor dust to reveal environmental and human health risk around ASGM in Amansie West district, Ghana. Indoor and outdoor dust samples were collected from Manso Abore and Manso Nkwanta in Ashanti Region. Concentration of Hg in the samples were analyzed using a direct Hg analyzer. The mean and median value of Hg concentration in the indoor dust (n = 31) were 2.2 ± 3.6 mg/kg and 0.72 mg/kg respectively while that of the outdoor dust (n = 60) were 0.19 ± 0.48 mg/kg and 0.042 mg/kg, respectively. The mean and median Hg concentration in indoor dust were about 11 and 17 times higher respectively than that in the outdoor dust. The Hg concentration in the indoor dust was statistically significantly higher than that of the non-miner in Manso Abore (p < 0.05) but was not significant in Manso Nkwanta, probably due to higher mining activity. The geo-accumulation index of the outdoor dust ranged from unpolluted to extremely polluted while that of the indoor dust ranged from moderately polluted to extremely polluted. Health risk assessments suggested that there was no potential non-carcinogenic health effect for Hg exposure relating to the dust to residents living in rooms of miners and non-miners. [ABSTRACT FROM AUTHOR]

In the study, the secondary explosion characteristics of TiH 2 dust with different particle sizes induced by hydrogen-oxygen detonations were studied, using a shock tube with semi-open and seal conditions. The processes of dispersal and deflagration were analyzed by a high-speed camera, and the explosion temperature and pressure were measured with the two-color pyrometer technique and pressure sensors, respectively. The experiment results showed that the dust clouds of TiH 2 with smaller particle sizes were larger in volumes and more liable to combust. With the decrease of particle size, the deflagration processes of TiH 2 dust became more intense, while their average temperatures had reverse trends, that is, lager particle sizes had higher average deflagration temperatures. Compared with the semi-open condition of shock tube, the duration of combustion under the confined condition was prolonged and the shock waves were enhanced for the wall reflection, which made the ignition of TiH 2 dust more possible and the subsequent deflagration more violent. Furthermore, the effects of semi-open and seal conditions of shock tube on the peak pressures of secondary explosion were different, compared with no TiH 2 dust addition, the peak pressures of secondary explosion with TiH 2 powders decreased in semi-open condition but increased in seal condition. [Display omitted] • Secondary explosion of TiH 2 dust induced by hydrogen detonation were simulated. • Dust lifting characteristics of TiH 2 under the high-speed airflow were studied. • Dynamic flame temperature distributions of TiH 2 dust explosion were mapped. • Gas-solid two-phase interaction effects during TiH 2 dust explosion were analyzed. [ABSTRACT FROM AUTHOR]

Polar dust has been discovered in a number of local active galactic nuclei (AGN), with radiation-driven torus models predicting a wind to be its main driver. However, little is known about its characteristics, spatial extent, or connection to the larger scale outflows. We present the first JWST /MIRI study aimed at imaging polar dust by zooming on to the centre of ESO 428-G14, part of the Galaxy Activity, Torus, and Outflow Survey (GATOS) survey of local AGN. We detect extended mid-infrared (MIR) emission within 200 pc from the nucleus. This polar structure is co-linear with a radio jet and lies perpendicular to a molecular gas lane that feeds and obscures the nucleus. Its morphology bears a striking resemblance to that of gas ionized by the AGN in the narrow-line region. We demonstrate that part of this spatial correspondence is due to contamination within the JWST filter bands from strong emission lines. Correcting for the contamination, we find the morphology of the dust continuum to be more compact, though still clearly extended out to |$r\approx 100 \, \rm pc$|⁠. We estimate the emitting dust has a temperature of |$\sim 120\, \rm K$|⁠. Using simple models, we find that the heating of small dust grains by the radiation from the central AGN and/or radiative jet-induced shocks is responsible for the extended MIR emission. Radiation-driven dusty winds from the torus is unlikely to be important. This has important implications for scales to which AGN winds can carry dust and dense gas out into their host galaxies. [ABSTRACT FROM AUTHOR]

JWST /NIRCam obtained high angular resolution (0.05–0.1 arcsec), deep near-infrared 1–5  |$\mu$| m imaging of Supernova (SN) 1987A taken 35 yr after the explosion. In the NIRCam images, we identify: (1) faint H2 crescents, which are emissions located between the ejecta and the equatorial ring, (2) a bar, which is a substructure of the ejecta, and (3) the bright 3–5  |$\mu$| m continuum emission exterior to the equatorial ring. The emission of the remnant in the NIRCam 1–2.3  |$\mu$| m images is mostly due to line emission, which is mostly emitted in the ejecta and in the hotspots within the equatorial ring. In contrast, the NIRCam 3–5  |$\mu$| m images are dominated by continuum emission. In the ejecta, the continuum is due to dust, obscuring the centre of the ejecta. In contrast, in the ring and exterior to the ring, synchrotron emission contributes a substantial fraction to the continuum. Dust emission contributes to the continuum at outer spots and diffuse emission exterior to the ring, but little within the ring. This shows that dust cooling and destruction time-scales are shorter than the synchrotron cooling time-scale, and the time-scale of hydrogen recombination in the ring is even longer than the synchrotron cooling time-scale. With the advent of high sensitivity and high angular resolution images provided by JWST /NIRCam, our observations of SN 1987A demonstrate that NIRCam opens up a window to study particle-acceleration and shock physics in unprecedented details, probed by near-infrared synchrotron emission, building a precise picture of how an SN evolves. [ABSTRACT FROM AUTHOR]

The structure and phase transition of a two‐dimensional (2D)$$ \left(2\mathrm{D}\right) $$ dusty plasma, confined by an anisotropic power‐law potential and interacting via a screened Coulomb potential, were investigated using Monte Carlo simulations. The study varied the number of particles (N$$ N $$), screening strength (k$$ k $$), eccentricity parameter (α$$ \alpha $$), and confinement power parameter (n$$ n $$) to characterize the system's structural properties. [ABSTRACT FROM AUTHOR]

\nHIGHLIGHTSThis research examines particulate matter with a diameter of 2.5 micrometers (PM2.5) and ozone (O3) variation across the climatic mesoregions of Alagoas. Mean PM2.5 and O3 concentrations across three mesoregions were as follows: East (5.91; 44.22 μg.m−3), Hinterland (6.90; 44.18 μg.m−3), and Arid (7.03; 44.23 μg.m−3). Spatial and temporal variations were observed, with PM2.5 concentrations highest in the northwest (NW) and O3 concentrations in the east (E), influenced by local sources, weather, and transportation. Differences between rainy and dry years were noted, attributed to biomass burning and dust particle transport. This study establishes a baseline for understanding air quality, lacking monitoring stations, aiding policymaking. It provides insights into PM2.5 and O3 dynamics, with PM2.5 concentrations highest in the NW and lower O3 concentrations in the E. Temporal variations emphasize the need for dynamic monitoring. Positive correlations between PM2.5 and O3 highlight complex relationships. Practical implications include proactive policymaking and the necessity for monitoring stations. Rigorous statistical methodologies inform model selection, enhancing environmental data understanding. Despite changes in land use, studies on extreme probability distributions are limited, emphasizing the need for robust methodologies for environmental data analysis to address air pollution challenges effectively in Alagoas. Spatio-temporal variability of the airborne pollutant criteria measured in Alagoas.Database of air pollutants of the state of Alagoas.Significant difference in the concentration of air pollutants between the dry and rainy seasons.Correlation between air pollutantsSpatio-temporal variability of the airborne pollutant criteria measured in Alagoas.Database of air pollutants of the state of Alagoas.Significant difference in the concentration of air pollutants between the dry and rainy seasons.Correlation between air pollutants [ABSTRACT FROM AUTHOR]

In this paper, we apply quantum cosmology to investigate the early moments of a Friedmann–Lemaître–Robertson–Walker (FLRW) cosmological model, using Hořava–Lifshitz (HL) as the gravitational theory. The matter content of the model is a dust perfect fluid. We start studying the classical model. Then, we write the total Hamiltonian of the model, quantize it and find the appropriate Wheeler–DeWitt equation. In order to avoid factor ordering ambiguities, in the Wheeler–DeWitt equation, we introduce a canonical transformation. We solve that equation using the Wentzel–Kramers–Brillouin (WKB) approximation and compute the tunneling probabilities for the birth of that universe (TPWKB). Since the WKB wave function depends on the dust energy and the free coupling constants coming from the HL theory, we compute the behavior of TPWKB as a function of all these quantities. [ABSTRACT FROM AUTHOR]

At present, under the influence of environmental pollution, the color of architectural painting gradually darkens, loses luster, and even cracks when the pigment falls off, which seriously affects the long-term preservation of architectural painting. In order to study the damage mechanism of dust particles to the color of the architectural painting, this study took the archery tower at the West Gate as the research object, monitored the temperature and humidity of the indoor environment, and analyzed the composition of the dust by ICP-MS, IC, and XRD. The experimental results showed notable fluctuations in the indoor humidity in inner the archery tower at the West Gate during the monitoring period from January to March, which were not conducive to the preservation of wood-colored paintings. The 24-h average PM2.5 and PM10 concentrations, measured over 2 days in January, were beyond the National Ambient Air Quality Standard norms, and PM contains a large amount of soluble salts such as sulfate and nitrate, causing serious salt erosion and damage to the color painting layer. Through the simulation experiment of the color painting layer, it was revealed that the dust particles deposited on the surface of the color painting layer change the spectral characteristics of the color painting layer, and then cause the color layer to lose its original hue, fade become blurred, or darken. It was anticipated that this research would serve as a valuable reference for the preventive protection of the color painting layer of the archery tower at West Gate. [ABSTRACT FROM AUTHOR]

The Mg ii resonance doublet at 2796 Å and 2803 Å is an increasingly important tool to study cold, |$T \sim 10^{4}\,$|  K, gas – an observational-driven development requiring theoretical support. We develop a new Monte Carlo radiative transfer code to systematically study the joined Mg ii and Ly α escape through homogeneous and 'clumpy' multiphase gas with dust in arbitrary three-dimensional geometries. Our main findings are (i) the Mg ii spectrum differs from Ly α due to the large difference in column densities, even though the atomic physics of the two lines are similar. (ii) The Mg ii escape fraction is generally higher than that of Ly α because of lower dust optical depths and path lengths – but large variations due to differences in dust models and the clumpiness of the cold medium exist. (iii) Clumpy media possess a 'critical covering factor' above which Mg ii radiative transfer matches a homogeneous medium. The critical covering factors for Mg ii and Ly α differ, allowing constraints on the cold gas structure. (iv) The Mg ii doublet ratio |$R_{\rm MgII}$| varies for strong outflows/inflows (⁠|$\gtrsim 700 \,\mathrm{km\, s}^{-1}$|⁠), in particular, |$R_{\rm MgII}\lt 1$| being an unambiguous tracer for powerful galactic winds. (v) Scattering of stellar continuum photons can decrease |$R_{\rm MgII}$| from two to one, allowing constraints on the scattering medium. Notably, we introduce a novel probe of the cold gas column density – the halo doublet ratio – which we show to be a powerful indicator of ionizing photon escape. We discuss our results in the context of interpreting and modelling observations as well as their implications for other resonant doublets. [ABSTRACT FROM AUTHOR]

Three-dimensional dust density maps are crucial for understanding the structure of the interstellar medium of the Milky Way and the processes that shape it. However, constructing these maps requires large data sets and the methods used to analyse them are computationally expensive and difficult to scale up. As a result, it has only recently become possible to map kiloparsec-scale regions of our Galaxy at parsec-scale grid sampling. We present all-sky three-dimensional dust density and extinction maps of the Milky Way out to 2.8 kpc in distance from the Sun using the fast and scalable Gaussian Process algorithm Dustribution. The sampling of the three-dimensional map is l, b, d  = 1° × 1° × 1.7 pc. The input extinction and distance catalogue contains 120 million stars with photometry and astrometry from Gaia DR2, 2MASS and AllWISE. This combines the strengths of optical and infrared data to probe deeper into the dusty regions of the Milky Way. We compare our maps with other published 3D dust maps. All maps quantitatively agree at the 0.001 mag pc−1 scale with many qualitatively similar features, although each map also has its own features. We recover Galactic features previously identified in the literature. Moreover, we also see a large under-density that may correspond to an inter-arm or -spur gap towards the Galactic Centre. [ABSTRACT FROM AUTHOR]

All-inorganic CsPbX 3 (X = Cl, Br, I) perovskite quantum dots (QDs) exhibit substantial potential in optoelectronics, rendering them valuable materials for next-generation lighting. However, the high cost and substantial usage of Cs present challenges. This study investigates the impact of NaF and/or ZnO modifiers on the network topological structure of CsPbBr 3 QDs-embedded sodium borosilicate (SBS) glass. The incorporation of NaF and ZnO not only reduces Cs consumption and energy requirements during heat treatment but also enhances the stability and optical properties of CsPbBr 3 QDs. Through a combination of experimental analysis and molecular dynamics (MD) simulations, we explore the changes in the SBS glass network topology induced by these modifiers. The results demonstrate that the addition of these modifiers effectively alters the topological structure of SBS glass, providing outstanding water and heat resistance for the embedded CsPbBr 3 QDs. This suggests that the NaF and ZnO co-modified CsPbBr 3 QDs-embedded SBS glass, with improved stability and optical characteristics, exhibits great promise for applications in optoelectronics. [ABSTRACT FROM AUTHOR]

High pathogenicity avian influenza viruses (HPAIVs) have caused major epizootics in recent years, with devastating consequences for poultry and wildlife worldwide. Domestic and wild ducks can be highly susceptible to HPAIVs, and infection leads to efficient viral replication and massive shedding (i.e., high titres for an extended time), contributing to widespread viral dissemination. Importantly, ducks are known to shed high amounts of virus in the earliest phase of infection, but the dynamics and impact of environmental contamination on the epidemiology of HPAIV outbreaks are poorly understood. In this study, we monitored mule ducks experimentally infected with two H5N8 clade 2.3.4.4b goose/Guangdong HPAIVs sampled in France in 2016–2017 and 2020–2021 epizootics. We investigated viral shedding dynamics in the oropharynx, cloaca, conjunctiva, and feathers; bird-to-bird viral transmission; and the role of the environment in viral spread and as a source of samples for early detection and surveillance. Our findings showed that viral shedding started before the onset of clinical signs, i.e., as early as 1 day post-inoculation (dpi) or post-contact exposure, peaked at 4 dpi, and lasted for up to 14 dpi. The detection of viral RNA in aerosols, dust, and water samples mirrored viral shedding dynamics, and viral isolation from these environmental samples was successful throughout the experiment. Our results confirm that mule ducks can shed high HPAIV titres through the four excretion routes tested (oropharyngeal, cloacal, conjunctival, and feather) while being asymptomatic and that environmental sampling could be a non-invasive tool for early viral RNA detection in HPAIV-infected farms. [ABSTRACT FROM AUTHOR]

Humans have occupied the Alps over most of the Holocene. Yet, continuous records on the impact of using montane resources and landscapes are scarce or confined to segregated areas or periods. We present a high-resolution geochemical record of the last 4800 years from the ombrotrophic peatland Piller Moor in the Central Alps (Tyrolean Oberland, western Austria), using inductively coupled mass plasma spectrometry (ICP-MS) and highly efficient inter-calibrated portable X-ray fluorescence analysis (pXRF). Fluctuations of metal enrichment factors (EF) for lead (Pb), copper (Cu), zinc (Zn) and antimony (Sb), accumulation rates of anthropogenic lead (Pb anth AR) and mineral matter (MAR), based on titanium (Ti), are in line with archaeological and pollen evidence for human presence and environmental change. Periods of intensified, erosive land use are indicated by MAR around 4400 cal BP, 3400 cal BP and, very prominently, at 2400 cal BP. After low MAR in the early Middle Ages, soil disturbances reappear around 1200 cal BP (750 AD), after 200 cal BP (1750 AD) and during the 20th century AD. We found evidence that metallurgy was practised in the area as early as 4450 cal BP, again from 3500 to 2900 cal BP and episodically between 2400 and 1400 cal BP. The Central Alps were presumably a source of increased Pb-emissions in the post-Roman period from 1500 to 1400 cal BP (450–550 AD). Generally, our findings suggest that mining predates archaeological and historical evidence. Following a continuous increase since the Middle Ages, atmospheric Pb EF and Pb anth AR peak around 1980 AD. The record of mineral atmospheric input illustrates the notable impact of human activities on soil erosion and dust entrainment in the Central Alps. Furthermore, links between Little Ice Age cold phases and reduced human impact and mining are established. Our high-resolution peat-geochemistry data quantifies atmospheric deposition of mineral matter and Pb, which act as proxies for landscape evolution and metallurgy on a local and regional scale. It provides new insights and a deeper understanding of the interaction of climate, environment and humans in mountainous landscapes like the Central Alps. [ABSTRACT FROM AUTHOR]

A positive correlation was observed between the enantiomeric excess (ee) of L-isovaline (L-iVal) and the degree of aqueous alteration (AqA) of carbonaceous meteorites. The origin of this remarkable phenomenon has remained enigmatic from two points of view: First, the correlation is between seemingly unrelated observables-nothing about AqA is of chiral characteristics; and second, following the accepted assumption that circularly polarized light (CPL) was the origin of the observed meteoritic ee of L-amino acids (AAs), it remined unclear why some of the observed levels of the ee of L-iVal in that correlation are significantly higher than those observed in laboratory simulations or those obtained from circular dichroism (CD) g-factor calculations. The current proposition accounting for this picture attributes late AqA conditions of the meteoritic parent bodies as providing the grounds for amplification of early initially CPL-generated low levels of L-ee. For reasons summarized below, this interpretation, which treats the CPL event and the AqA process as occurring in wide-time separated eras, is re-visited. An alternative interpretation of the observed correlation and of the high ee-values, is provided. It focuses on hydrophilic dust-aggregates clouds in wet star-forming regions in early presolar times, where both the CPL event and the grounds leading to the later AqA processes of the parent bodies, occurred. This mechanism removes the time separation between the initial ee formation and the AqA of the parent body, and replaces it with parallel processes, providing a scenario to the observation of high ee's without total destruction, and to the apparent AqA/L-ee correlation. Although iVal is at the focus of this report, the steps of the development of the alternative mechanism and the conclusions that arise from it, are relevant and applicable to the general observations of L-ee's of meteoritic AA's. [ABSTRACT FROM AUTHOR]

AbstractDust explosions are common and highly hazardous industrial accidents that occur rapidly and involve complex changes in particle structure. Traditional experimental methods struggle to capture the time-resolved information of the explosion process, limiting the in-depth study of its dynamic mechanisms. Synchrotron radiation small-angle x-ray scattering (SAXS) offers a novel method to study the microscopic dynamics of dust particles during explosions. Utilizing high-flux x-rays from synchrotron facilities, coupled with fast detectors and specialized explosive chambers, SAXS provides high temporal and spatial resolution alongside nondestructive detection capabilities. It is expected to obtain information on particle morphology changes during dust explosions. This contribution first introduces the basic characteristics and hazards of dust explosions, reviews the current research status and challenges, and then expounds on the basic principles and advantages of synchrotron radiation SAXS. Finally, the potential of this method in real-time monitoring of dust explosion characteristics and enhancing understanding of explosion mechanisms was explored. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) panels are similar in many aspects to the leaves of trees, both are standing in the Sun to capture the sunlight, however, PV panels get soiled especially in desert areas, while the leaves remain clean to a very good extent. The question is, why leaves remain clean while PV panels get soiled quite easily? The leaves are hanging on the stem of trees and these stems are flexible to motion, such that if the wind blows in any direction over the stem it vibrates allowing any deposited particle to fall off the surface. The objective of this research is to develop a fixation method for PV panels similar to the stems of trees, such that the panel can vibrate as the wind blows in order to minimize dust accumulation. Different fixation methods for the PV panel are designed, and the air flow around the panel is simulated using the CFD package Ansys Fluent. It has been found that a PV panel pivoted at its lower edge, such that it can revolve around the lower edge, together with a vertical wind shield attached to its upper edge and a spring attached at the middle of its backside has the largest vibration amplitude due to the applied wind compared to the other designs. Experiments have been done to infer the influence of the new fixation method of the PV panel on dust accumulation over the panel. After 6 weeks of operation, it has been found that the efficiency of the PV panel that is flexibly fixed has dropped by only 5%, while the efficiency of the panel that is rigidly fixed has dropped by 25%. It can be concluded that a PV panel operating a light post should be fixed on a flexible base that allows the panel to vibrate as the wind blows over it in order to mitigate dust. [ABSTRACT FROM AUTHOR]

The article discusses an art installation by Giuseppe Penone called Sculture di linfa, which explores the relationship between nature and culture through the use of tree trunks and leather sheets imprinted with tree bark. The artist focuses on the sensory experience rather than symbolic meaning. The article also mentions Georges Didi-Huberman's exploration of the significance of bark, particularly in relation to the birch trees at Birkenau concentration camp. Gerhard Richter's response to the Holocaust is discussed, highlighting his use of painting to capture and convey the trauma. Richter's Birkenau series, displayed at the Alte Nationalgalerie, invites viewers to reflect on the unimaginable horror of the Holocaust through the metaphor of the mirror. The text also notes the association between the word "birch" and the color red-brown in Richter's work, and mentions that the Birkenau cycle is permanently displayed in a museum near Auschwitz. [Extracted from the article]

It is increasingly recognized that light-absorbing impurities (LAI) deposited on snow and ice affect their albedo and facilitate melting processes leading to various feedback loops, such as the ice albedo feedback mechanism. Black carbon (BC) is often considered the most important LAI, but some areas can be more impacted by high dust emissions. Iceland is one of the most important high latitude sources for the Arctic due to high emissions and the volcanic nature of the dust. We studied optical properties of volcanic dust from Iceland and Chile to understand how it interacts with the Sun's radiation and affects areas of deposition as LAI. Optical properties of dust samples were measured at the laboratory of the Finnish Geospatial Research Institute (FGI) using the latest setup of the FGI's goniospectrometer. We found that, depending on the particle size, the albedo of dry volcanic dust on the visible spectrum is as low as 0.03, similar to that of BC, and the albedo decreases with increasing particle size. Wet dust reduces its albedo by 66% compared to dry sample. This supports the comparability of their albedo reducing effects to BC as LAIs, and highlights their significant role in albedo reduction of snow and ice areas. The potential use of the results from our measurements is diverse, including their use as a ground truth reference for Earth Observation and remote sensing studies, estimating climate change over time, as well as measuring other ecological effects caused by changes in atmospheric composition or land cover. [ABSTRACT FROM AUTHOR]

The removal and discharge of coal powders from coalbed methane wellbore is the key to maintaining continuous production. For this reason, based on the submerged jet theory, the force and migration starting conditions of coal powder particles deposited at the bottom of the coalbed methane well are analyzed by analyzing the cohesiveness of coal powders, and a model for the starting and migration of coal powders at the bottom of the well under submerged jet conditions is established; Considering the adhesion between coal dust, the adhesion coefficient is used to characterize the adhesion between particles, a mechanical model of coal dust particles deposited at the bottom of the well is established, and the corresponding calculation formula for the outlet flow rate of the coal dust cleaning nozzle is derived. The fluid mechanics parameters of the bottom of the well coal dust cleaning under different conditions are obtained, and the numerical simulation method is used to simulate the whole process of jet flushing of the bottom of the well coal dust deposited, and the effect of the bottom of the well jet flushing of coal dust deposits is analyzed, providing a theoretical basis for the bottom of the well coal dust flushing process. [ABSTRACT FROM AUTHOR]

The concentration of various potentially toxic metals (Pb, Cd, As, Ni, Zn, and Cr) in street dust samples collected from Mehran city, Iran, was analyzed. The samples were obtained during normal traffic conditions, NTT, prior to the Arbaeen ceremony, as well as after the pilgrims' return, which corresponds to high traffic time, HTT. Street dust samples were analyzed for HM content using ICP-OES, following acid digestion. The subsequent evaluation of the data involved the application of the geo-accumulation index, enrichment factor, and potential ecological risk index (PER) and health risk assessment. The findings demonstrate a notable increase in the levels of HMs during HTT compared to the NTT. The highest enrichment values for Pb and Cd were observed in Mehran Street dust during the HTT. The mean of PER for all sampling points increased to 138.24, indicating a moderate-potential ecological risk at this time. Based on the health risk assessment, it was found that the hazard index for all samples was below one. The incremental lifetime cancer risk was below 10−6. This indicates that the exposed population is not exposed to substantial health risks. Despite the heavy traffic caused by the Arbaeen ceremony in this area and the high enrichment of HMs, along with potential ecological risks, no significant health risks were observed for individuals exposed to street dust. However, it is important to note that the continuation of this trend, in the absence of proper traffic management, could lead to significant environmental and health problems in the future. [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]

In Thailand, the volatile period from 2019 to 2023 was marked by changing material and political atmospheres. Air pollution, the COVID‐19 pandemic, and government restrictions on speech transformed how Thai citizens breathed and how they related to the monarchy. Understanding this period as a history of breath reconceptualizes the citizen‐body as volumetric, recasting politics as an intermaterial practice. Breath, its vibrations, and its constraints, as it moves across the topologies of the respiratory system, generate densely material, richly symbolic political relations that bind citizens to one another, to the polity, and to the world. Small particles, dust, viruses, speech restrictions, and tear gas constrained the breath of Thai citizens while shaping the conditions in which dissenting vibrations could shake the country's cosmologies. Attention to the citizen‐body as volumetric thus recasts the lungs as relational chambers of political capacity, resituating political analysis within the material world and suggesting that all politics are, in some sense, environmental. [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]

Autoignition and smoldering of coal dust have gained great safety concern in both industry and mining due to their high susceptibility to heating. To better understand their controlling mechanism, autoignition and smoldering of bituminous coal particles (1-mm diameter) and coal powders (0.1-mm diameter) in the form of bulk layer heated by 4–45 kW m−2 thermal radiation levels were systematically studied. The results showed that the critical heat flux was between 4 and 5 kW m−2 for both samples. Under 5 kW m−2, no morphology change was detected on surface, but internal ignition and smoldering occurred. Partial oxidation and intense glowing ignition were observed under heat fluxes of 10 and 15–45 kW m−2, respectively. The average glowing temperature was 782.4 ± 19.6 K, while the maximum temperature during smoldering changed in 976–1206 K. Smoldering spread rate of powder sample was larger than that of particle sample due to emerged cracks during heating and larger specific surface area, and both spread rates linearly depended on heat flux. The linear dependency of ignition time to the power of − 0.5 on heat flux in classical ignition theory was found still valid for glowing ignition of both samples, and apparent thermal inertia and critical heat fluxes were quantitatively estimated. In all smoldering tests, mass loss rates exhibited a bimodal feature, with first peak charactering moisture evaporation, while the second peak indicating coal-oxygen reaction. Under 35 and 45 kW m−2 heat fluxes, a unique faint blue flame appeared which depended more on surface temperature than on mass flux of pyrolyzates. This contribution may deliver useful reference for evaluation of coal fire risk and help mitigate hazard of smoldering in practical applications. [ABSTRACT FROM AUTHOR]

The effect of dust pollution on the photosynthesis and respiration parameters of foliose lichens Hypogimnia physodes (L.) Nyl, Lobaria pulmonaria (L.) Hoffm. and Peltigera aphthosa (L.) Willd., collected near the bauxite mine (Komi Republic, Russia) was investigated. Microscopic analysis showed that fine dust particles were mainly on the thalli surface, with a few mineral inclusions in the thalli medulla. The deposition of dust particles caused significant changes in the optical properties of the lichen surface in the visible and infrared spectral regions. A number of spectral indices (BRI, REP, RES, WI) sensitive to lichen pollution by dust emissions from the bauxite mine were identified due changes in the reflectance spectra of the thalli. Shading of the algal layer by mineral particles deposited on the thalli surface did not affect the content of photosynthetic pigments and PS II photochemical activity parameters. At the same time, lichen CO2-exchange parameters were observed to change. Lichen thalli from the polluted area were characterized by lower values of net CO2 uptake in the moderate light conditions (150 µmol PAR/m2 s), and the proportion of dark respiration in the gas exchange was 1.5 to 2 times higher than the values for thalli from background site. A 2-fold decrease in cytochrome respiration capacity was observed in thalli from the affected area. In thalli of L. pulmonaria and P. aphthosa, the energetically inefficient alternative respiratory pathway capacity increased 1.5‑fold and in H. physodes the activity of residual respiration increased more than 3.5-fold. The results obtained allowed an assessment of the chronic dust pollution effects on the foliose lichens symbionts functioning. The data may be useful for environmental biomonitoring. [ABSTRACT FROM AUTHOR]

Cosmic very small dust grains (VSGs) contain 100 to 10000 atoms, making them a mesoscopic system with specific thermal and optical characteristics due to the finite number of atoms within each grain. This paper focuses on graphite VSGs which contain free electrons. The energy level statistics devised by Kubo (1962 , J. Phys. Soc. Jpn. 17, 975) are used for the first time to understand the thermal properties of free electrons in graphite VSGs. We show that the shape irregularity of the grains allows graphite VSGs to absorb or emit photons at submillimeter wavelengths or longer; otherwise, the frequency is limited to above a few THz. Additionally, we consider the decrease in Debye temperature due to the surface effect. VSGs have an extremely small volume, resulting in limited thermal energy storage, especially at low temperatures. Since a VSG is able to emit a photon with energy smaller than its internal energy, this determines the maximum frequency of the emitted photon. We develop a Monte Carlo simulation code to track the thermal history of a dust grain, considering the stochastic heating from the absorption of ambient photons and radiative cooling. This approach is applied to the interstellar environment to compute the spectral energy distributions from the interstellar graphite dust grains. The results show that graphite VSGs emit not only the mid-infrared excess emission, but also a surplus emission from submillimeter to millimeter wavelengths. [ABSTRACT FROM AUTHOR]

In order to theoretically understand dust properties in the circumgalactic medium (CGM), we construct a dust evolution model that incorporates the evolution of grain size distribution. We treat the galaxy and the CGM as separate one-zone objects, and consider the mass exchange between them. We take into account dust production and interstellar dust processing for the galaxy based on our previous models, and newly incorporate sputtering in the hot phase and shattering in the cool phase for the CGM. We find that shattering increases the dust destruction (sputtering) efficiency in the CGM. The functional shape of the grain size distribution in the CGM evolves following that in the galaxy, but it is sensitive to the balance between sputtering and shattering in the CGM. For an observational test, we discuss the wavelength dependence of the reddening in the CGM traced by background quasar colors, arguing that, in order to explain the observed reddening level, a rapid inflow from the CGM to the galaxy is favored because of quick dust/metal enrichment. Small grain production by shattering in the CGM also helps to explain the rise of dust extinction toward short wavelengths. [ABSTRACT FROM AUTHOR]

The spatial distribution of dust particles in protoplanetary disks affects dust evolution and planetesimal formation processes. The vertical shear instability (VSI) is one of the candidate hydrodynamic mechanisms that can generate turbulence in the outer disk region and affect dust diffusion. Turbulence driven by the VSI has a predominant vertical motion that can prevent dust settling. On the other hand, the dust distribution controls the spatial distribution of the gas cooling rate, thereby affecting the strength of VSI-driven turbulence. Here, we present a semi-analytic model that determines the vertical dust distribution and the strength of VSI-driven turbulence in a self-consistent manner. The model uses an empirical formula for the vertical diffusion coefficient in VSI-driven turbulence obtained from our recent hydrodynamical simulations. The formula returns the vertical diffusion coefficient as a function of the vertical profile of the cooling rate, which is determined by the vertical dust distribution. We use this model to search for an equilibrium vertical dust profile where settling balances with turbulent diffusion for a given maximum grain size. We find that if the grains are sufficiently small, there exists a stable equilibrium dust distribution where VSI-driven turbulence is sustained at a level of α z  ∼ 10−3, where α z is the dimensionless vertical diffusion coefficient. However, as the maximum grain size increases, the equilibrium solution vanishes because the VSI can no longer stop the settling of the grains. This runaway settling may explain highly settled dust rings found in the outer part of some protoplanetary disks. [ABSTRACT FROM AUTHOR]

This study investigates the measurement of plasma‐grown nanoparticles, comparing ex situ scanning electron microscopy (SEM) and an in situ light scattering method which is based on Mie theory and utilizes a neural network for evaluation. The research reveals that the particle size distribution (PSD) is normal and very narrow, supporting the common assumption of monodisperse particle clouds. Importantly, the study finds that the spread of the PSD increases proportionally with the mean size, suggesting varied growth rates based on the radius of the spherical dust grains. Both methods produce consistent results, which encourages the use of the interference‐free, real‐time, light‐based Mie method in similar studies. [ABSTRACT FROM AUTHOR]

Purpose: Studies have recently shown a correlation between the elemental components of coal dusts, including potassium aluminosilicates, and the lung response as a potential driver for lung diseases associated with inhalation of coal dust. Here we aimed to systematically review the evidence for the association between exposure to potassium bearing dusts and lung outcomes in human studies as well as adverse cellular response in animal/cell culture studies. Methods: A systematic search of the National Library of Medicine (PubMed), Embase and Web of Science was conducted in May 2024. Studies regarding exposure to potassium bearing dusts and aluminosilicates and respiratory consequence were included in the search. Articles were screened, with a secondary assessment for relevance and extraction of key information using a systematic review process. Results: We identified 64 studies, of which 35 were human studies, 22 involved animal experiments and 12 were in vitro studies with 5 papers having both in vivo and in vitro studies. Our review found some evidence that a range of potassium rich dusts increased incidence of respiratory symptoms and lung diseases, although the effect on radiological changes in the lung and pulmonary function loss was not consistent. The in vivo animal and in vitro studies consistently demonstrated an inflammatory response and cytotoxic effect after exposure to these dusts. Conclusion: Given complexity in the dust compositions and lack of direct evidence attributing these specific responses to potassium, we are not able to conclude the effect of potassium minerals in coal on development of respiratory diseases, warranting further research. [ABSTRACT FROM AUTHOR]

We explore the dynamical behaviour of dust particles that populate the surface of inner optically thick protoplanetary discs. This is a disc region with the hottest dust and is of a great importance for planet formation and dust evolution, but we still struggle to understand all the forces that shape this environment. In our approach, we combine results from two separate numerical studies, one is the wind velocity and density distributions obtained from magnetohydrodynamical simulations of accretion discs, and the other is a high-resolution multigrain dust radiation transfer. In our previous paper in the series, we described the methodology for utilizing these results as an environmental input for the integration of dust trajectories driven by gravity, gas drag, and radiation pressure. Now we have two improvements, we incorporate time changes in the wind density and velocity, and we implement the non-radial radiation pressure force. We applied our analysis on the Herbig Ae and T Tau stars. We confirm that the radiation pressure force can lead to dust outflow, especially in the case of more luminous stars. Additionally, it opposes dust accretion at the inner disc edge and reduces dust settling. These effects are enhanced by the disc wind, especially in the zone where the stellar and the disc magnetic fields meet. Our results suggest that dust grains can stay in the hottest disc region for an extended period and then end up ejected into the outer disc regions. [ABSTRACT FROM AUTHOR]

We investigate the chemical evolution of complex organic molecules (COMs) in turbulent discs using gas-ice chemical reaction network simulations. We trace trajectories of dust particles considering advection, turbulent diffusion, gas drag, and vertical settling, for 10 |$^6$| yr in a protoplanetary disc. Then, we solve a gas-ice chemical reaction network along the trajectories and obtain the temporal evolution of molecular abundances. We find that the COM abundances in particles can differ by more than two orders of magnitude even when the ultraviolet (UV) fluence (i.e. the time integral of UV flux) received by the particles are similar, suggesting that not only the UV fluence but also the time variation of the UV flux does matter for the evolution of COMs in discs. The impact of UV fluence on molecular abundances differs between oxygen-bearing and nitrogen-bearing COMs. While higher UV fluence results in oxygen being locked into CO |$_2$|⁠ , leading to reduced abundances of oxygen-bearing COMs such as CH |$_3$| OCH |$_3$|⁠ , mild UV exposure can promote their formation by supplying the precursor radicals. On the other hand, nitrogen is not locked up into specific molecules, allowing the formation of nitrogen-bearing COMs, particularly CH |$_3$| NH |$_2$|⁠ , even for the particle that receives the higher UV fluence. We also find that the final COM abundances are mostly determined by the inherited abundances from the protostellar core when the UV fluence received by dust particles is less than a critical value, while they are set by both the inherited abundances and the chemistry inside the disc at higher UV fluence. [ABSTRACT FROM AUTHOR]

We have investigated the behaviour of three strong near-infrared diffuse interstellar bands (DIBs) at λ13177 Å, λ14680 Å, and λ15272 Å, on a larger sample of sightlines and over a wider range of extinctions than previously studied, utilizing spectra from three observatories. We applied two telluric correction techniques to reduce atmospheric contamination and have used Gaussian fits to characterize the DIB profiles and measure equivalent widths. We confirmed strong and approximately linear correlations with reddening of the λ13177 Å, λ14680 Å, and λ15272 Å DIBs, extending them to higher reddening values and strengthening their link to interstellar matter. Modelling of the λ14680 Å DIB profiles revealed intrinsic variations, including line broadening, linked to their formation processes. This effect is particularly pronounced in the Galactic Centre (GC) environment, where multiple diffuse molecular clouds along the line of sight contribute to line broadening. We have detected one new DIB candidate at λ14795 Å on sightlines with high reddening. [ABSTRACT FROM AUTHOR]

To solve the problem of point source dust in industrial production, we employed a large-diameter pleated filter cartridge (fold ratio α values of 1.23, 1.47, 1.7, and 1.8). However, its complex pleated structure affects the stable operation state of the dust collector. The experimental results show that with the gradual increase of the fold ratio of the filter, the filter cleaning efficiency ε increases at first and then decreases, and an α value of 1.47 shows the best results. The average effective filtration area Ae ¯ increases with increasing fold ratio over the same run time. The higher the dust concentration, the lower is the Ae ¯ ; the ratio of the average effective filtration area to the theoretical filtration area β ¯ decreased from 80.2% (α = 1.8) and 80% (α = 1.47) to 77% (α = 1.7). [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental investigation of the influence of electrode configuration on corona discharge and particle collection under ambient climatic conditions in Blade-to-Plane Electrostatic Precipitator (BP-ESP). In an experimental-scale electrostatic precipitator (BP-ESP), electrodes of different shapes (blade, saw blade with small tooth, and saw blade with large tooth) were tested. The experiments were performed with three types of dust particles having a mean size of about 5 µm, 10 µm, and 45 µm. An aerosol spectrometer was used to characterize the chemical composition of these dust particles injected into the ESP. Different DC-applied voltages have been taken into account for both positive and negative polarities. Results showed that a high current was generated with a saw blade electrode with large teeth which increased the particle collection efficiency, for both polarities. The negative corona discharge is overall more effective than the positive one for the different configurations of electrodes and dust particles used. [ABSTRACT FROM AUTHOR]

Pulse-jet cartridge filters are widely used in industrial dust removal. However, the accumulation of highly sticky dust can cause irreversible blockage of cartridges. This is primarily due to the humidity of the air on the cleaning performance of the filter cartridge. Therefore, this article proposed a new method to solve it by changing the injection air source (nitrogen, compressed air after suction dryer treatment and compressed air after cold dryer treatment), the influence of humidity on system strength and dust residues was assessed. We define absolute humidity above 10 g m−3 as a high humidity condition and vice versa as a low humidity condition. The conclusions are that the injection effect only considers the water content of the injection air source: nitrogen > compressed air after suction dryer treatment > compressed air after cold dryer treatment. In low humidity conditions, the injection air source is the main influence factor, plus the water content of the injection air source, the greater the resistance of the system and the dust residues. In high humidity conditions, the humidity of the air is the most important influence. When the gas-solid concentration and filtration wind speed are constant, the system strength and dust residues increase with the increase in humidity. This study provides new ideas and reliable data sources for the industrial collection of adhesive dust. [ABSTRACT FROM AUTHOR]