Fine Dust Particles Research Articles

EHD stability of a viscid fluid cylinder surrounding by viscous/inviscid gas with fluid-particle mixture in permeable media

The article is concerned with Electrohydrodynamics (EHD) instability of an incompressible dielectric viscous fluid in a vertical cylinder that surrounds a dielectric viscous/inviscid gas. The incompressible packing has microscopic fine dust particles of a consistent size. An unchanged tangential electric field influences the system which is saturated in porous media. Given their importance in the stability picture, the fundamental equations that regulate the particle mixture are constructed. The linear stability approach is employed to analyze the system. The motivation for tackling this problem lies in the growing interest in a variety of practical physics and engineering disciplines. The profiles of velocity fields and pressure are evaluated by the conventional normalized approach. A transcendental dispersion relationship connects the rate of growth and the wave number of the wave propagation. The procedure produces several numbers of non-dimensional characteristics of the problem at hand. Appropriate findings have been yielded that match the existing results in the available literature.

Characterization of the aerosol field over Sofia, Bulgaria, using contact and passive-remote-sensing methods and instruments

The atmospheric aerosol particles, called also atmospheric particulate matter, that include also fine dust particles (FDP), are an important factor conditioning many physical processes in the atmosphere, affecting the climate and the air quality, and posing serious potential risks to the human health. In this regard, the regular observation of the atmospheric aerosol load and its dynamics is a valuable source of scientific information concerning these processes, while also allowing the relevant institutions to undertake preventive measures in cases of a dangerous FDP concentration increase. This work is devoted to estimating experimentally, by passive optical sensing and contact measurements, some important integral microphysical and optical characteristics and their dynamics of the aerosol ensembles over Sofia, Bulgaria. The results obtained outline the springtime values of the aerosol number and mass concentration in the near-ground urban atmosphere, the depth of the atmospheric boundary layer, the aerosol optical depth at different optical wavelengths, the water vapor content, and the Ångström exponent at the wavelengths of 440/870 nm.

Modelling of the detachment of adhesive dust particles during bulk solid particle impact to enhance dust detachment functions

The detachment of fine adhered dust particles during bulk particle contacts is studied with an adhesive Discrete Element Method (DEM) to describe the carrier and the dust particle motion. Further, dust detachment functions are realized in a non-adhesive DEM, in which only the coarse carrier particles are tracked as one composed bulk particle. The implemented detachment functions include three criteria, a normal and a tangential lift-off condition as well as a rotational condition. These functions are benchmarked based on dust-resolved adhesive DEM simulations by varying crucial parameters in the course of particle-particle and particle-wall contacts. In advance, the adhesive force is calibrated using experimental single drop tests. The detachment criteria reflect the physical detachment of individual dust particles well assuming dust particles with a narrow size distribution. The application of the enhanced dust detachment functions therefore allows to predict dust release of individual dust particles with significantly less computing time.

The DPA-derivative 11S, 17S-dihydroxy 7,9,13,15,19 (Z,E,Z,E,Z)-docosapentaenoic acid inhibits IL-6 production by inhibiting ROS production and ERK/NF-κB pathway in keratinocytes HaCaT stimulated with a fine dust PM10

11 S, 17S-dihydroxy 7,9,13,15,19 (Z,E,Z,E,Z)-docosapentaenoic acid (DoPE) is a derivative of docosapentaenoic acid, a specialized pro-resolving mediator of inflammation such as lipoxins, resolvins, maresins, and protectins. PM10 is a fine dust particle that induces oxidative stress, DNA damage, inflammation, aging, and cancer. The anti-inflammatory mechanism of DoPE, however, has not yet been elucidated. In these studies, we investigated whether DoPE has anti-inflammatory effects in human keratinocyte HaCaT cells. We demonstrated that DoPE suppressed PM10-induced expressions of IL-6 mRNA and protein in human HaCaT keratinocytes. We also investigated the modulating effects of DoPE on reactive oxygen species (ROS) and mitogen-activated protein kinase (MAPK). ROS production, extracellular signal regulated kinase (ERK) phosphorylation, and translocation of nuclear factor-kappa B (NF-kB) p65 and NF-kB activity were suppressed by DoPE in PM10-stimulated HaCaT cells. Collectively, our results demonstrated that DoPE inhibited IL-6 expression by reducing ROS generation, suppressing ERK phosphorylation, and inhibiting translocation of NF-kB p65 and NF-kB activity in PM10-stimulated HaCaT cells, suggesting that DoPE can be useful for the resolution of the inflammation caused by IL-6.

Experimental investigations on tensile and flexural properties of epoxy resin matrix waste marble dust and tamarind shell particles reinforced bio-composites

A great gain has been made in recent years in the creation of hybrid bio-composites by combining different natural resources as reinforcement and filler elements. The waste marble dust particles and tamarind shell powder particles were additional to the epoxy resin matrix in this experiment to study the tensile and flexural characteristics of the epoxy resin matrix. Tamarind shell powder and waste marble dust particles are used as reinforcing materials. To create hybrid bio-composite specimens, researchers varied the reinforcement material weight percentages while maintaining the epoxy resin weight percentage as constant. Hot injection moulding was used to create hybrid biocomposites boards. The hybrid bio-composite specimens for tensile and flexural tests are cut away from the hybrid bio-composite boards using the water jet machining method as per ASTM specifications. Research shows that adding small amounts of fine waste marble dust particles and tamarind shell powder to an epoxy resin matrix enhances the hybrid bio-composites' tensile and flexural capabilities significantly. The maximum tensile strength, yield strength, elongation percentage, flexural strength and flexural modulus of 34.63 MPa, 32.81 MPa, 3.3 %, 36.17 and 38.53 MPa were obtained from 35 wt% tamarind shell powder and 15 wt% waste marble dust powder composite specimens (C4 Composites) correspondingly.

Properties of Saharan Dust Versus Local Urban Dust—A Case Study

AbstractOn June 29–30, 2019, the Barcelona Dust Forecast Center with Non‐hydrostatic Multiscale Model (NMMB/BSC‐Dust) and the Navy Aerosol Analysis and Prediction System forecasted huge amounts of mineral dust over Poland. The Hybrid Single Particle Lagrangian Integrated Trajectory model confirmed uniquely fast (120 hr) long‐range air‐mass transport form North Africa to Poland. This remarkable dust event was observed using lidar at the Aerosol, Clouds and Trace Gases Research InfraStructure site in Warsaw, Central Poland; the only site equipped with Raman‐Mie polarization water vapor lidar in East‐Central Europe. The excellent capabilities of PollyXT lidar allowed to obtain an impressive number of 31 full sets of aerosol optical properties profiles, which enabled study of dust properties evolution on a rare hourly scale. The analyses were completed with the separation of fine and coarse mode dust particles form non‐dust particles using the POlarization‐LIdar PHOtometer Networking algorithm. Huge amount of an exceptionally pure mineral dust from Sahara measured in the free troposphere was characterized by a gradually decreasing coarse dust fraction (76%–21%) with a peak of fine dust fraction (67%) and particle linear depolarization ratio (26%) in the middle of the event. Within the boundary layer, a local urban dust mixed with pollution was observed with fine mode dust particles dominating (44%) and lower particle linear depolarization ratio (7.4%). The influx of pure mineral dust has been unique to this geographical region and will therefore be a reference point for future research and comparative studies.

Ecological technologies for environmental objects remediation

The greening of urban areas, including roofs of buildings, can be used as a means to reduce the concentration of pollutants in the air in large cities. In the context of high built-up density, when it is impossible to pick out free space, greening the roofs of existing buildings is a sole solution. In this paper, the movement of air flows and the diffusion of fine dust particles smaller than 2.5 microns (PM2.5) are modelled for a Moscow region with consideration of external non-stationary factors. The computation is made in ENVI-met program via the CFD analysis. In the future, it is planned to assess options for complex landscaping of the studied site, including greening the roofs of buildings along areas with a high content of fine particles, in order to reduce the concentration of PM2.5.

Spatio-temporal changes of AOD in Xinjiang of China from 2000 to 2019: Which factor is more influential, natural factor or human factor?

Aerosol optical depth (AOD), which represents the optical attenuation, poses a major threat to the production activity, air quality, human health and regional sustainable development of arid and semi-arid areas. To some degree, AOD shows areal air pollution level and possesses obvious spatio-temporal characteristics. However, long-time sequences and detailed AOD information can not be provided due to currently limited monitoring technology. In this paper, a daily AOD product, MODIS-based Multi-angle Implementation of Atmospheric Correction (MAIAC), is deployed to analyze the spatio-temporal characteristics in Xinjiang Uygur Autonomous Region from 2000 to 2019. In addition, the importance of influencing factors for AOD is calculated through Random Forest (RF) Model and the propagation trajectories of pollutants are simulated through Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) Model. Spatio distribution of AOD presents a tendency that AOD value in northern Xinjiang is low while the value in southern Xinjiang is high. Regions with high AOD values are mainly concentrated in Tarim Basin. AOD in southern Xinjiang is the highest, followed by that in eastern Xinjiang and AOD value in northern Xinjiang is the lowest. Seasonal variation of AOD is significant: Spring (0.309) > summer (0.200) > autumn (0.161) > winter (0.158). Average AOD value in Xinjiang is 0.196. AOD appears wavy from 2000 to 2014 with its low inflection point (0.157) appearing in 2005, and then increases, reaching its peak in 2014 (0.223). The obvious downward tendency after 2014 shows that the use of coal to natural gas (NG) conversion project improves the conditions of local environment. According to RF Model, NG contributes most to AOD. HYSPLIT Model reveals that aerosol in southern Xinjiang is related to the short-distant carriage of dust aerosol from the Taklimakan Desert. Aerosol there can affect Inner Mongolia through long-distant transport. Blocked by the Tianshan Mountains, fine dust particles can not cross the Tianshan Mountains to become a factor contributing to AOD in northern Xinjiang.

Experimental investigation on highly efficient collection and cleaning for fine coal dust particles by dry-wet mixed chemical method

The dust removal efficiency of dry dust collectors is low, especially with the decrease of coal dust particle size. To improve the collection and removal efficiency of fine coal dust particles, a dry-wet mixed chemical method was designed. The chemical polymer solution was transformed into fine droplets by an ultrasonic atomizer and added into the dust removal process. A new type of chemical polymer (AM/AA-CMCS) was prepared by modifying carboxymethyl chitosan. The atomizing effect, chemical structure, and surface morphologies of AM/AA-CMCS were investigated in detail. The adsorption process between AM/AA-CMCS and coal dust was simulated from a molecular level. Through the experimental platform, the variation of filtration resistance, filtration cycle, residual pressure, and dust emission concentration were measured under different dust particle size conditions. The results show that the AM/AA-CMCS could better wet, bind, and agglomerate coal dust particles. Compared to dry-type dedusting, the capture and removal of coal dust particles of less than 500 mesh in dry-wet chemical dedusting conditions are improved more significantly. The research results are not limited to the fine coal dust particles produced in mine systems, but could also provide a reference for the application of dust collectors in other energy and industrial fields.

Quantitative analysis of fine dust particles on moss surfaces under laboratory conditions using the example of Brachythecium rutabulum

The identification of a model organism for investigations of fine dust deposits on moss leaflets was presented. An optical method with SEM enabled the quantitative detection of fine dust particles in two orders of magnitude. Selection criteria were developed with which further moss species can be identified in order to quantify the number of fine dust particles on moss surfaces using the presented method. Among the five moss species examined, B. rutabulum had proven to be the most suitable model organism for the method presented here. The number of fine dust particles on the moss surface of B. rutabulum was documented during 4 weeks of cultivation in the laboratory using SEM images and a counting method. The fine dust particles were recorded in the order of 10 μm–0.3 μm, divided into two size classes and counted. Under laboratory conditions, the number of particles of the fine fraction 2.4 μm–0.3 μm decreased significantly.

Disease modeling and drug screening using human airway organoids: a systematic review

Increasing levels of fine environmental dust particles due to industrialization and emerging respiratory illnesses, such as coronavirus disease 2019, pose serious threats to human life. The use of organoids for disease modeling and drug screening has been proposed as a new treatment approach for respiratory diseases. As discussed in this review, various pathogen models, genetic disease models, and patient-derived lung cancer organoid models have been reported for disease modeling and drug testing using human airway organoids. Despite these promising recent advances, several issues must be addressed before the disease modeling potential of human airway organoids can be fully realized. If systematic methods to produce mature airway organoids can be developed, and reproducible organoid models can be implemented using standardized protocols, airway organoids will likely become valuable respiratory disease models and drug screening tools.

Verification of particle matter generation due to deterioration of building materials as the cause of indoor fine dust

Particles of fine dust are pollutants that adversely affect indoor air quality and exacerbate human respiratory diseases. The aging of the building was pointed out as a source of fine dust indoors. The aging of buildings has various causes of deterioration. During various deterioration, friction adversely affects the building floor finish. In this study, an accelerated friction deterioration device was used to confirm the generation of fine dust particles through the frictional deterioration of floor finishes in buildings. The study found that the concentration of fine dust particles attributed to deteriorating flooring was 327 mg/m3 in PM2.5 and 4828 mg/m3 in PM10 and confirmed that particle distribution differs depending on the surface of the flooring. Particles of 10 µm or less were observed through particle analysis. The study confirmed that fine dust particles did not diffuse in a specific direction and that the detected fine dust particles could be attributed to deterioration. Further research is needed on the detection of fine dust in degraded building finishing materials.

Application of green tea catechins, polysaccharides, and flavonol prevent fine dust induced bronchial damage by modulating inflammation and airway cilia

Airborne fine dust particles (FDPs) have been identified as major toxins in air pollution that threaten human respiratory health. While searching for an anti-FDP reagent, we found that green tea extract (GTE) and fractions rich in flavonol glycosides (FLGs) and crude tea polysaccharides (CTPs) had protective effects against FDP-stimulated cellular damage in the BEAS-2B airway epithelial cell line. The GTE, FLGs, and CTPs significantly increased viability and lowered oxidative stress levels in FDP-treated cells. Combined treatment with GTE, FLGs, and CTPs also exerted synergistic protective effects on cells and attenuated FDP-induced elevations in inflammatory gene expression. Moreover, the green tea components increased the proportion of ciliated cells and upregulated ciliogenesis in the airway in FDP-stimulated BEAS-2B cells. Our findings provide insights into how natural phytochemicals protect the airway and suggest that green tea could be used to reduce FDP-induced airway damage as an ingredient in pharmaceutical, nutraceutical, and also cosmeceutical products.

An assessment of the spatial extent of polar dust using satellite thermal data

The effect of mineral dust aerosols and subsequent deposition in polar regions has historically been underestimated in climate models. Dust aerosols increase melt rates by reducing surface albedo and modifying atmospheric radiative properties. In this study 127,413 satellite images covering the Arctic and Antarctic from 2007 to 2019 were assessed for dust content using thermal infrared wavelengths. The results show a strong linear trend in which the relative spatial extent of dust (RSED) increased annually by 0.31% in the Arctic (8.5% to 12.1%) and 0.19% in the Antarctic (5.2% to 7.5%). Seasonally, the maximum aggregated average RSED occurred in the Arctic during boreal winter (11.2%), while the Antarctic peaked in austral spring (9.5%). Maximum RSED rates occurred in boreal winter/austral summer (Dec–Jan–Feb) for both polar regions. The data suggests that finer dust particles are more efficiently distributed by aeolian processes leading to higher RSED values that are not necessarily reflective of polar dust loading models.

Numerical Analysis of Ultrasonic Multiple Scattering for Fine Dust Number Density Estimation

In this study, a method is presented for estimating the number density of fine dust particles (the number of particles per unit area) through numerical simulations of multiply scattered ultrasonic wavefields. The theoretical background of the multiple scattering of ultrasonic waves under different regimes is introduced. A series of numerical simulations were performed to generate multiply scattered ultrasonic wavefield data. The generated datasets are subsequently processed using an ultrasound data processing approach to estimate the number density of fine dust particles in the air based on the independent scattering approximation theory. The data processing results demonstrate that the proposed approach can estimate the number density of fine dust particles with an average error of 43.4% in the frequency band 1–10 MHz (wavenumber × particle radius ≤ 1) at a particle volume fraction of 1%. Several other factors that affect the accuracy of the number density estimation are also presented.

Impact of surface contamination on elemental composition of Sanguinea (Pall.) leaves

The leaves of C. sanguinea Pall. have the potential to accumulate dust on the surface. As the fine dust particles contain various chemical elements (ChEs), we studied the ChE composition in the leaves with different degrees of dust contamination to assess the impact on assay results. The samples of C. sanguinea leaves collected in the Kemerovo region (Russia) were divided into two groups based on the visual condition of plant material: clean leaves and dust contaminated leaves. The total ash assay revealed higher ash content, exceeding pharmacopoeial standards in the dust contaminated group. Dust contaminated leaf samples demonstrated significantly higher concentrations of many ChE: Si, Fe, Al, Na, Ti, Ni, Zr, Cr, V, Pb, La, Ga, Y, Sc and Yb comparing to non-contaminated plant material. The values of potentially hazardous ChEs were significantly lower than the maximum levels specified for medicinal raw materials in all studied samples.

Impact of surface contamination on elemental composition of Crataegus sanguinea (Pall.) leaves

The leaves of C. sanguinea Pall. have the potential to accumulate dust on the surface. As the fine dust particles contain various chemical elements (ChEs), we studied the ChE composition in the leaves with different degrees of dust contamination to assess the impact on assay results. The samples of C. sanguinea leaves collected in the Kemerovo region (Russia) were divided into two groups based on the visual condition of plant material: clean leaves and dust contaminated leaves. The total ash assay revealed higher ash content, exceeding pharmacopoeial standards in the dust contaminated group. Dust contaminated leaf samples demonstrated significantly higher concentrations of many ChE: Si, Fe, Al, Na, Ti, Ni, Zr, Cr, V, Pb, La, Ga, Y, Sc and Yb comparing to non-contaminated plant material. The values of potentially hazardous ChEs were significantly lower than the maximum levels specified for medicinal raw materials in all studied samples.

Artificial Intelligence-Based Smart Solution to Reduce Respiratory Problems Caused by Air Pollution

Globally, air pollution is a significant concern for human health. Artificial sources of particulate matter (fine dust particles suspended in the air), especially PM2.5, are the significant constituents in indoor air pollution and prominently leads to many lung-related illnesses. Research suggests that around 90% of people spend ~22 hours inside every day, either at a home, office, factory, or restaurant. Plants act as a natural detoxifying agent by taking particulate matter (PM) waste from the atmosphere. Our hypothesis tested whether placing specific plants indoors can reduce levels of PM inside by using principles of biomedical engineering and machine-learning approaches. Our data showed that plants improved the overall quality of the air in the room. Levels of PM2.5 were decreased dramatically in the rooms compared to the average levels measured outside the house. As higher PM exposure in humans is associated with many diseases, our research suggests that plant-based interventions coupled with a sensor and cloud-based application using artificial intelligence may be useful in the long run to reduce indoor air pollution.

Removal Rates of NOx, SOx, and Fine Dust Particles in Textile Fabrics Coated with Zeolite and Coconut Shell Activated Carbon

An effective dipping method for coating of textile fabrics with porous materials is proposed on the basis of the use of epoxy solution consisted of resins, crosslinkers, and dilution solutions. The removal rates of nitrogen oxides (NOx), sulfur oxides (SOx), and fine dust particles in the coated textile fabrics are accessed. The textile fabrics made of polyester are used to effectively reduce fine dust particles through static electricity. Zeolite and coconut shell activated carbon are used as porous material to reduce SOx and NOx, respectively. The effects of the epoxy content and dilution solution types on the SOx removal rate of textile fabrics coated with zeolite are evaluated to determine the optimum coating conditions. In addition, the effects of external environmental conditions, such as washing and freeze thawing, on the SOx and NOx removal rates of the textile fabrics coated with porous materials using the optimum coating conditions are examined. The test results show that the SOx removal rate of textile fabrics coated with zeolite decreases with the increase in the epoxy content. The decrease is 2.9 times larger for textile fabrics coated using deionized water than those coated using isopropyl alcohol. After one wash, the SOx removal rate decreases dramatically. However, the decrease is reduced by 16% when the epoxy content ratio is increased by 0.5%. The effects of washing and freeze thawing on the SOx and NOx removal rates of textile fabrics coated using the deionized water diluted with the epoxy content ratio of 2% are minimal. Consequently, to maintain stable SOx and NOx removal rates under external environmental conditions such as washing and freeze thawing, 98% deionized water dilution and 2% epoxy content ratio are required for the optimum coating of textile fabrics with zeolite and coconut shell activated carbon.

Study of the potential use of the invasive marine algae Undaria pinnatifida in the preliminary development of a functional textile

Seaweeds are considered to be an important source of relevant chemical substances or bioactive compounds of great usefulness in the medical, cosmetic, pharmaceutical or food industry. Recently, some seaweed had been used to produce or incorporate in fibers in order to manufacture technical textiles in which functional ingredient of the seaweed are exploited in the health and body care area. The brown seaweed Undaria pinnatifida (Undaria) has an important nutritive value being consumed as food in several Asian countries. As well Undaria is required in cosmetic or dermatology medicine given the presence of other bioactive chemical substances known as phycocolloids. The objective of this study was to explore the potential use of Undaria in a preliminary development of a functional textile. A soft bilaminate textile with a high crease recovery and an efficient release of mucilage, was achieved using a fine dust (particle of <0.26 mm) of Undaria between two layers of nonwoven. The best combination of the two layers of nonwoven was laminate and fine spundbond. The extract of Undaria used in our experimentation had minerals and vitamins with positive effect to the human skin, besides it is no irritant when applied to healthy or abraded skin. Further research focused in the incorporation of this alga in nonwoven fibers is required. We expect to obtain a textile with a dermatologic use in the near future; so as to turn Undaria into a resource susceptible to exploitation given the specie is considered a worldwide plague.