This study presents, for the first time, field evidence of complete, irreversible processing of solid calcium carbonate (calcite)-containing particles and quantitative formation of liquid calcium nitrate particles apparently as a result of heterogeneous reaction of calcium carbonate-containing mineral dust particles with gaseous nitric acid. Formation of nitrates from individual calcite and sea salt particles was followed as a function of time in aerosol samples collected at Shoresh, Israel. Morphology and compositional changes of individual particles were observed using conventional scanning electron microscopy with energy dispersive analysis of X-rays (SEM/EDX) and computer controlled SEM/EDX. Environmental scanning electron microscopy (ESEM) was utilized to determine and demonstrate the hygroscopic behavior of calcium nitrate particles found in some of the samples. Calcium nitrate particles are exceptionally hygroscopic and deliquesce even at very low relative humidity (RH) of 9-11% which is lower than typical atmospheric environments. Transformation of non-hygroscopic dry mineral dust particles into hygroscopic wet aerosol may have substantial impacts on light scattering properties, the ability to modify clouds and heterogeneous chemistry.
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Sci Rep
December 2024
School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, China.
The dolomite dust-emulsified asphalt composite (DAC) with excellent mechanical properties was successfully prepared using alkali activation. The effects of different alkali concentrations and emulsified asphalt contents on the mechanical properties of the materials were studied. And the micro-mechanisms of its mechanical performance changes were analyzed through SEM and XRD characterization.
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December 2024
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Sand and dust storms (SDS) can cause adverse health effects, with the oxidative potential (OP) and environmentally persistent free radicals (EPFRs) inducing oxidative stress. We mapped the OP and EPFRs concentrations at 1735 sites in China during SDS periods using experimental data for 2021-2023 and a random forest model. We examined 855,869 hospitalizations during SDS events for 2015-2022 in Beijing, China.
View Article and Find Full Text PDFEnviron Sci Technol
December 2024
Climate and Environmental Physics, Physics Institute, and Oeschger Centre for Climate Change Research, University of Bern, Sidlerstrasse 5, Bern 3012, Switzerland.
This study presents the integration of the single-particle extinction and scattering (SPES) method in a continuous flow analysis (CFA) setup. Continuous measurements with the instrument allow for the characterization of water-insoluble particles in ice cores at high resolution with a minimized risk of contamination. The SPES method can be used to investigate particles smaller than 1 μm, which previously could not be detected by instruments typically used in CFA.
View Article and Find Full Text PDFSci Rep
December 2024
Geotechnical Institute, TU Bergakademie Freiberg, Freiberg, Germany.
The development of new urban areas necessitates building on increasingly scarce land, often overlaid on weak soil layers. Furthermore, climate change has exacerbated the extent of global arid lands, making it imperative to find sustainable soil stabilization and erosion mitigation methods. Thus, scientists have strived to find a plant-based biopolymer that favors several agricultural waste sources and provides high strength and durability for sustainable soil stabilization.
View Article and Find Full Text PDFDeveloping novel materials is an essential requirement in the engineering field. This study investigates the effects of incorporating wood dust particles on the mechanical and erosive wear properties of Luffa acutangula fiber (LAF)-reinforced phenol-formaldehyde composites, fabricated using the hand layup method with a constant 20% fiber content and varying wood dust particle contents of 0%, 10%, 20%, and 30%. Using the Taguchi method, the study identifies the optimal combination for minimizing erosive wear - 20% wood dust content, 45 m/s impact velocity, 60° impingement angle, 600 μm erodent size, and 60 mm standoff distance-achieving a minimum erosion rate of 189.
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