Search Results (5,468)

Because dust-emission processes driven by local, small-scale winds (e.g., terrain-induced winds) are difficult to accurately capture with mesoscale or larger-scale predictive models, this study employed a CFD-Lagrangian particle-tracking approach to numerically simulate near-surface dust release and transport under different atmospheric stability conditions in the same local flow field. The novelty of this work was the integration of MOST-based stable/neutral/unstable inflow construction with Lagrangian particle tracking, enabling a consistent comparison of stability effects within one framework. This framework is useful for assessing local blowing-sand impacts on short-range receptors. A near-surface source term was specified for PM10-class mineral dust, and particles were emitted using a vertically exponential allocation. Simulations were conducted over a kilometer-scale flow domain containing an idealized cosine hill, and the low-level concentration patterns and dispersion-height variations in the resulting dust cloud were analyzed. Compared with neutral conditions, stable stratification produced higher near-surface concentrations and a lower dispersion height, whereas unstable stratification yielded lower near-surface concentrations and a higher dispersion height; as the $\left|L\right|$ increased, the unstable cases gradually approached the neutral state. The influence of reference wind speed exhibited clear stability dependence: under stable conditions, stronger winds intensified the buoyancy-related suppression of dust dispersion, while under unstable conditions, stronger winds inhibited the vertical spreading of the dust cloud. In addition, reduced air density representative of plateau environments resulted in lower dust-cloud concentrations and higher dispersion heights. These findings highlight the coupled effects of stratification and wind speed on near-field dust dispersion and provide a reference for assessing local dust emissions over complex terrain. Full article

Dust and sand storms occurring in northern China are strongly controlled by near-surface aerodynamics, yet the spatial heterogeneity of these processes remains poorly understood. We obtained field measurements of the wind above gobis, sandy surfaces, and dry lakebeds in the Hexi Corridor Desert and Heihe River Basin, and sandy surfaces in northern China. First, the slope of wind profile (a₁) reveals distinct drag reversal with increasing wind speed: under low winds, a₁ increases from sandy to dry lakebed to gobi surfaces, whereas under high winds, actively saltating sandy surfaces exhibit the highest a₁, surpassing gobi and dry lakebed. Second, the dynamic feedback between sediment transport and aerodynamics is clear: at below-threshold winds, friction velocity ($u_{*}$) and aerodynamic roughness length (z₀) are lowest for sand; however, as wind speed increases to initiate significant saltation, the sandy surface develops the highest $u_{*}$ and z₀, highlighting the dominant role of grain-borne roughness. Third, the focal height (z_f) shows regional disparity, varying by up to two orders of magnitude for both sandy and gobi surfaces, with a strong correlation to local gravel coverage. This work provides spatially explicit parameterizations of surface type, offering a physical basis for modeling dust emission and transport in northern China and similar arid regions globally. Such parameterizations are essential for developing reliable early warning systems and evidence-based land management strategies. These advances contribute directly to ecosystem sustainability and community resilience in vulnerable arid and semi-arid regions under climate change. Full article

Welding fumes in the shipbuilding industry severely threaten workers’ health. This study systematically investigated welding fume exposure in a Chinese shipyard, analyzing mass concentration, particle size distribution, and harmful metal content using data from 2015. Differences were observed across welding sites and processes. Confined spaces and gas metal arc welding (GMAW) were associated with significantly higher exposure levels. Welding fumes were dominated by particles smaller than 1.00 μm, a distribution influenced by welding site, distance from the welding spot, and process. Iron (Fe) and manganese (Mn) were the predominant metal components, with concentrations significantly higher in respirable dust than in total dust. Risk assessment indicated minimal non-cancer hazards for Fe, zinc, and copper. However, Mn posed the predominant risk (Hazard Quotient >> 1), while nickel (Ni) and chromium (Cr) also exceeded safety thresholds at most points. Consequently, confined spaces and GMAW should be prioritized as key control targets in shipyards, as respirable dust rich in metal-bearing particles poses greater health risks. Therefore, China urgently requires the establishment of specific occupational exposure limits for respirable welding fumes. Additionally, personal sampling is more focused and efficient than area sampling for precise occupational health risk assessment due to the greater mobility of welding operations. Full article

This study addresses the problem of efficient utilization of aspiration dust (AD) generated during crushing of high-carbon ferrochrome (HCFeCr). To solve this issue, a briquetting technology was proposed, involving aspiration dust blended with dry gas-cleaning dust (20 wt.% as filler) and an organic polymer binder (3 wt.%). The produced briquettes demonstrated high mechanical strength (average 195 kg per briquette in splitting strength and 98% drop resistance), ensuring maximum integrity during transportation and handling. Pilot-industrial remelting of 35 tons of briquettes in a 1.8 MVA direct current electric arc furnace (DC EAF) confirmed the effectiveness of the proposed technology for HCFeCr production. Chromium recovery into the alloy reached 94%, which is 3–4% higher compared to remelting of loose dust. The specific electric energy consumption was 1600 kWh/t, representing a 29% reduction compared to loose dust processing. The produced metal met commercial grades FeCr800–FeCr900 specifications. Additional advantages included elimination of dust formation, reduction in fines generation during crushing of the final metal to 15%, and improved environmental performance. The developed technology represents an economically and environmentally viable solution for comprehensive recycling of ferroalloy dust waste. Full article

Dust generated during coal mining and transportation poses serious threats to miners’ health, operational safety, and the surrounding environment. However, comprehensive review studies on dust suppression in coal mines remain limited, particularly those integrating dust movement laws with numerical simulation approaches. This review presents a systematic and reproducible analysis of dust control methods in coal mines with a particular focus on numerical simulation. Current research progress and development trends are summarized from three aspects: structural optimization of dust suppression devices, optimization of operating conditions, and ventilation system design. Existing studies indicate that structural improvements mainly concentrate on nozzle geometry, diameter, installation position, and spraying distance, while operating condition optimization primarily involves pressure regulation. Due to the complexity and high cost of full-scale experimental platforms, ventilation system optimization is largely achieved through numerical simulation, supplemented by field measurements. Studies based purely on numerical simulations remain limited in addressing the chemical modification of dust removers; however, with the advancement of molecular dynamics techniques, this area may represent a promising direction for future research. Full article

In desert regions, frequent aeolian dust events lead to rapid dust accumulation on greenhouse films, critically compromising light transmittance and inhibiting crop growth. To address this challenge, this study integrated Computational Fluid Dynamics–Discrete Phase Model (CFD-DPM) simulations with field experiments to conduct a comprehensive investigation spanning from microscopic deposition mechanisms to macroscopic physiological responses. Particle characterization revealed a distinct aerodynamic sorting effect, wherein fine particles (<65 μm) preferentially adhered to film surfaces driven by airflow, contrasting sharply with the gravitational settling of coarse ground particles. Numerical simulations further confirmed that as wind speeds increased from 2 to 7 m/s, dust deposition rates exhibited a significant exponential reduction, with accumulation predominantly concentrated in the windward and wake zones. The dust layer covering the film induced a substantial reduction in the indoor daily light integral (DLI), which leads to influence tomato growth that stunted plant height and suppressed the net photosynthetic rate. Physiologically, antioxidant enzyme activities exhibited an initial surge followed by a decline, reflecting photosynthetic constraints and oxidative stress. Consequently, a high-frequency cleaning interval of 7–14 days is recommended to significantly enhance photosynthetic capacity and stress resilience. Full article

Understanding the composition and amount of waste is crucial for the health and development of communities. Panic and the unpredictable situation of COVID-19 caused significant demands for food, which resulted in high pressure on food waste and waste management systems. To determine the change in waste composition in Northern Cyprus during the COVID-19 pandemic, questionnaires were prepared and distributed through the media and via email. This study found that household waste generation per capita was 0.91 kg with a 6% error when compared with a conventional waste composition study performed by the European Union in 2016. According to the results, the quantity of domestic waste decreased during the pandemic, while garden waste increased. Additionally, the results show that 27% of plastic waste came from cleaning purposes. As face mask usage and tea consumption increased during the pandemic, these materials were incorporated as additives into marble-dust-modified cement paste to develop sustainable construction composite. The mechanical performance of the proposed material was evaluated by measuring the flexural and compressive strengths of specimens cured for 7, 28, and 56 days. Eco-efficiency metrics derived directly from mechanical data provided strong environmental engineering insight. When assessed per unit of compressive function, cement intensity increased with mask dosage, indicating reduced binder efficiency despite batch-level cement savings. Furthermore, waste diversion per unit strength increased with mask content, but progressively larger compressive penalties accompanied this benefit. Within this trade-off, low to intermediate mask dosages offered the most validified balance between waste diversion and mechanical performance. Full article

The rapid expansion of wind energy into complex and extreme environments has renewed interest in vertical-axis wind turbines (VAWTs) due to their omnidirectional operation, compact footprint, and potential resilience under harsh operating conditions. However, the current understanding of VAWT performance remains fragmented across aerodynamic, structural, operational, and application-specific studies. This systematic review aims to synthesize and critically evaluate VAWT research with environmental stressors as the central organizing framework, addressing performance behavior, adaptation challenges, and future research pathways. Literature searches were conducted in the Web of Science Core Collection, Scopus, IEEE Xplore, ScienceDirect, and SpringerLink databases, with Google Scholar used as a supplementary source, covering publications from 2000 to January 2026. Eligible studies focused on VAWTs operating under non-standard or extreme conditions, including icing, offshore, desert, high-turbulence, and thermally severe environments. A systematic quality assessment was applied to evaluate methodological rigor and environmental characterization, and the findings were synthesized using a qualitative–quantitative hybrid approach; no formal meta-analysis was performed. The review reveals substantial advances in unsteady aerodynamics, numerical modeling, and control strategies, but also identifies persistent discrepancies between high-fidelity simulations and real-world performance due to simplified modeling assumptions and limited full-scale experimental validation. Quantitative findings indicate that high turbulence can decrease the power output of large VAWTs by 23–42%, dust and sand in arid environments can reduce torque and power by ~25%, and air temperature increases from 15 °C to 60 °C can reduce the power coefficient of VAWTs by about 38%. Emerging approaches, including artificial intelligence-assisted design, adaptive turbine architectures, and climate-aware methodologies, show promise in addressing these limitations. The findings highlight the urgent need for coordinated long-term field measurements, improved multi-physics modeling, and interdisciplinary research to enhance the reliability and scalability of VAWTs in extreme environments. This review was not registered. Full article

The internal recycling of iron-rich fine residues is a crucial process for reducing the raw material loss and the carbon footprint in sustainable ironmaking and steelmaking. Traditionally, cement has been used as a binder to ensure the structural integrity of agglomerates during transport and charging. While cementitious binder can achieve the necessary structural support, it contributes significantly to the carbon footprint. This study investigated the effects of alternative biogenic binders and varying compaction pressures on the physical and mechanical properties of agglomerates produced from three different types of fine residues from steel (SR) and cast-iron (FR) production. In addition, the self-reducing capability and degree of metallization of these agglomerates were evaluated through pyrometallurgical experiments in a Tammann furnace. The resulting agglomerates exhibited sufficient mechanical strength and high iron recovery rates. These findings confirm that biogenic binders can effectively replace cementitious binders without compromising the self-reduction performance of the agglomerates. Full article

This study focused on children residing near a smelter in Baiyin, and investigated the impact mechanism of different soil particle sizes on children’s exposure to heavy metals. By analyzing the distribution pattern of concentrations and bioaccessibilities of typical heavy metals (Cd, Cr, Cu, Ni, Pb) across four particle size fractions (<63 μm, 63–150 μm, 150–250 μm, 250–352 μm), and incorporating the size-selective adherence characteristics of children’s hand-loaded dust, this research quantitatively assessed the contribution of each particle size fraction to children’s health risks from oral exposure. The results showed that fine particle size soil (<63 μm) exhibited both higher concentration and bioaccessibility of heavy metals, which were 1.3–1.9 times and 1.1–2.2 times higher, respectively, than those of the coarsest fraction (250–352 μm). The proportion of particles < 63 μm in children’s hand-loaded dust (64.3%) was significantly higher than that in ambient soil, demonstrating selective adherence towards finer particles during children’s exposure. Due to the particle size-selective effects on metal concentration, bioaccessibility, and actual child exposure, fine soil particles constituted the primary source of heavy metal exposure risk via oral ingestion in children. Soil particles with a size of <63 μm contributed 48–60% to the total exposure risk of the five heavy metals. Therefore, in the health risk assessment of soil around smelting plants, the influence of particle size on the occurrence characteristics of metals, bioaccessibility, and children’s actual exposure behavior should be considered concurrently to enhance the accuracy and targetability of assessment and control measures. Full article

To address the challenges posed by strong environmental disturbance during field observations of dust dispersion at highway construction sites, this study investigates the transport and diffusion patterns of construction dust (PM₁₀) by integrating numerical simulation with on-site measurements. Based on particle sampling parameters and wind conditions obtained from the target project, a construction PM₁₀ dispersion model was established using computational fluid dynamics (CFD). The wind direction that best matched the measured field data was selected as the reference condition, and the dispersion behavior of construction dust was simulated under different wind speeds and particle mass flow rates. The results indicate that larger wind-direction angles facilitate vertical dispersion of particulate matter, and higher wind speeds enhance long-distance transport while reducing near-source concentrations. Dust-suppression performance increases with barrier height, and under a low wind speed of 2 m·s⁻¹, a 3 m barrier achieves a PM₁₀ suppression efficiency of 73.6%. These findings provide quantitative evidence and technical support for PM₁₀ control in highway construction environments. Full article

This study addresses a research gap in integrated environmental and spatial assessments of municipal solid waste (MSW) systems in rapidly growing secondary cities in Central Asia. Using a mixed-method approach that combines field audits, GIS-based spatial analysis, environmental monitoring, and greenhouse gas modeling, the study evaluates waste composition, infrastructure coverage, and ecological risks in Shymkent, Kazakhstan. The results reveal uneven distribution of legal waste containers, a 5–7% annual increase in illegal dumping sites, and dust (TSP) concentrations exceeding WHO thresholds near active disposal zones. Spatial hotspot mapping identifies critical pressure areas in peripheral districts, while morphological audits show a rising share of plastics and construction debris. The findings support district-specific policy interventions, infrastructure modernization, and behavior-driven recycling incentives. The proposed methodology provides a replicable framework for sustainable MSW governance in urban contexts. These results contribute to evidence-based municipal waste governance and regional sustainability planning. Full article

Background: House dust mites (HDM) are one of the significant indoor allergen sources which cause IgE-mediated responses in most of the allergic individuals. HDMs are found in human habitats worldwide and Der p 2 is one of the major clinically relevant HDM allergens involved in triggering allergic diseases. The recombinant production of Der p 2 in plant systems provides a cost-effective and viable platform for developing diagnostic kits and allergen-specific immunotherapy. Methods: The D. pteronyssinus Der p 2 allergen was transiently expressed in Nicotiana benthamiana and its immunogenicity was evaluated in mice. The Der p 2 coding sequence was cloned into a geminiviral plant expression vector and introduced into N. benthamiana leaves via Agrobacterium tumefaciens-mediated infiltration. Recombinant Der p 2 proteins were purified from the crude extracts and confirmed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and Western blot. The immunogenicity of the plant-produced Der p 2 proteins was further evaluated by immunizing mice following a prime–boost immunization regimen, and Der p 2-specific antibody responses were assessed by ELISA. Results: Recombinant Der p 2 was successfully expressed and purified from N. benthamiana, and immunized mice developed high levels of Der p 2-specific IgG antibodies, with antibody titers increased after booster immunization. Conclusions: The results demonstrate that the transient expression of Der p 2 in plants is a feasible and effective strategy for producing immunologically active recombinant allergen proteins for diagnostic and potential clinical applications. Full article

Platform screen door (PSD) systems can reduce particulate matter (PM) levels at subway platforms, but transient particle migration between tunnels and platforms still occurs during door operation. Existing control measures, such as tunnel cleaning, ventilation optimization, onboard dust removal devices, and air curtain systems, mainly target background PM concentrations and generally function as passive mitigation strategies. However, the transient dynamics of tunnel-to-platform PM migration during PSD operation remain insufficiently understood. In this study, field measurements and numerical simulations were used to investigate PM migration under realistic subway operating conditions. Field observations were conducted to characterize the spatial distribution of PM and its relationship with tunnel piston wind. A numerical model based on the Discrete Phase Model (DPM) was then developed to simulate particle transport under different PSD operating sequences. The effects of PSD opening delay and opening duration on particle migration were examined to evaluate their influence on migration rates. The results show that adjusting the timing of PSD operation can significantly reduce tunnel-to-platform PM migration, whereas conventional air curtain configurations may enhance interzonal particle exchange under certain conditions. These findings improve the understanding of PSD-related PM transport and provide potential operational strategies for improving air quality in underground rail transit systems. Full article

Heavy metals in urban dust, derived from anthropogenic activities and natural sources, are considered potentially toxic elements for human health. The city of Puebla, located in Central Mexico, is one of the ten largest metropolitan cities in Mexico. Near this city is the Popocatépetl volcano, which contributes heavy metals through the emission of ash. The objectives of this study were to evaluate heavy metal contamination in urban dust and volcanic ash from the city of Puebla, and to determine the associated human health risks. Heavy metals were analyzed using an XRF spectrometer. The level of contamination was established according to the contamination factor, the geoaccumulation index and the contaminant load index. Furthermore, non-carcinogenic risk indices (HIs) were calculated to evaluate the health risk. The results revealed the presence of 18 elements (Ca, Cr, Cu, Fe, K, Mn, Nb, Ni, Pb, Rb, Sb, Sn, Sr, Ti, Y, V, Zn and Zr), with the highest concentrations found for most in urban dust samples, while Rb, Ca and K showed higher concentrations in ash samples. High levels of Sb and Sn contamination were found in 90 to 100% of the dust and ash samples, while Cr, Cu, Ni, Pb and Zn showed considerable levels of contamination in 60 to 90% of the samples. According to the US EPA thresholds, the health risk assessment indicated safe levels (HI < 0.25) for Cu, Fe, Mn, Ni, Pb, Sn, V and Zn in the urban dust and volcanic ash samples, while some of the samples exceeded the safety threshold (HI > 1) for Cr and Sb with respect to the child population in the city of Puebla. These results must be taken into consideration by environmental and government authorities, and the degree of pollution should be reduced accordingly. Full article