Soot nanoparticles result from incomplete combustion of fossil fuels, and have been exhibited, when released into the atmosphere, to be detrimental to air quality and human health. However, because of the inert and non-luminescent properties, probing the dynamics of soot in situ is still a challenge. Here we report a strong near-infrared laser pump and multi-color Rayleigh scattering probe approach to reveal soot dynamics in situ in a n-pentanol/air laminar diffusion flame at femtosecond time resolution. A size-dependent dynamical process of the pump-laser-induced soot swelling at femtosecond time scale and subsequent shrinking back to its original size at picosecond time scale is observed, in which both the swelling rise time and the shrinking decay time increase monotonically as the initial sizes of soot nanoparticles become larger. By characterizing the evolution time and intensity of the multi-color scattered probe light, the spatial distributions of different sizes of soot particles from the inception to the burnout regions of the flame are mapped, which provide useful information on exploring the formation and growth mechanisms of soot particles in flames.
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http://dx.doi.org/10.1364/OE.461947 | DOI Listing |
Sci Total Environ
January 2025
Direction Milieux et impacts sur le vivant, Institut National de l'Environnement Industriel et des Risques (INERIS), Verneuil en Halatte, France.
Emissions due to tires retread/repair and incineration are a cause of concern owing to the presence of nanoparticles in the products. The assessment exposure to humans hereto related is a challenge in an environmental context. The first object of this work is to develop a method to characterize the emission sources using online (counting and sizing) and offline measurements.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Ecole polytechnique - CNRS UMR7654, Palaiseau, Ile-de-France, France; Université Paris Cité - Inserm UMR-S1124, Paris, Ile-de-France, France.
Alzheimer's disease (AD) is the most common dementia in humans that today concerns 50 million individuals worldwide and will affect more than 100 million people in 2050. Except for familial AD cases (<5% of AD patients) for which AD pathology connects to mutations in critical genes involved in the processing of the amyloid precursor protein into neurotoxic Aß peptides, it remains unknown what provokes the overproduction and deposition of Aß peptides in the brain of sporadic AD cases (>95% of AD patients). Some nanosized materials, e.
View Article and Find Full Text PDFNanotheranostics
January 2025
Department of Research and Innovation, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Thandalam, Chennai - 602105, Tamil Nadu, India.
In an era where chemical synthesis of nanomaterial is accounting for the generation of toxic wastes, leading to nanotoxicity, the present work focuses on the extraction of carbon nanodots from available natural sources such as turmeric smoke. The extracted carbon nanodots were characterized and their physical and chemical attributes were confirmed. The antibacterial property of the isolated carbon nanodots was tested against coliforms and oral bacteria.
View Article and Find Full Text PDFEnviron Pollut
December 2024
State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
A multiple-site filter-sampling observation study was conducted in a coastal industrial city (Rizhao, 35°10'59″N, 119°23'57″E) to understand the main components, formation mechanisms, and potential sources of particulate matter. The average (±σ) mass concentration of PM across all the sites was 42 (±27) μg/m, with high variability (6∼202 μg/m). Water-soluble inorganic ions (WSIIs) were the major contributors (54%∼60%) to PM with mean values for sulfate (13 μg/m), nitrate (6 μg/m), and ammonium (7 μg/m) (SNA).
View Article and Find Full Text PDFMikrochim Acta
December 2024
Chemistry Institute, Federal University of Uberlândia, Uberlândia, MG, 38408-100, Brazil.
Babassu (Atallea sp.), a native palm tree from South America's Amazon produces bio-oil and biochar with significant potential for industrial applications. Babassu oil as a bio-based plasticizer is reported here for the first time to replace petrochemical alternatives in the production of conductive filaments for additive manufacturing purposes.
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