A modeless broadband dye laser is applied to probe inside optically dense fireballs generated by high explosives using single-shot, high resolution absorption spectroscopy. Despite attenuation of the main beam by 98%, high signal-to-noise ratio absorption spectra of Al, Ti, and AlO are readily obtained at resolutions of 0.007 nm, and luminosity from the fireball is strongly rejected. Detection limits for atomic species are less than 200 ppb. The method offers good time resolution of chemistry within the fireball, and scaling laws suggest that this technique should be valid in explosives tests at least up to the gram scale.
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http://dx.doi.org/10.1366/000370209789379268 | DOI Listing |
Sci Rep
December 2024
Department of Urology, Urological Science Institute, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-gu, Seoul, 03722, South Korea.
Carbon dots (CDs) are versatile nanomaterials that are considered ideal for application in bioimaging, drug delivery, sensing, and optoelectronics owing to their excellent photoluminescence, biocompatibility, and chemical stability features. Nitrogen doping enhances the fluorescence of CDs, alters their electronic properties, and improves their functional versatility. N-doped CDs can be synthesized via solvothermal treatment of carbon sources with nitrogen-rich precursors; however, systematic investigations of their synthesis mechanisms have been rarely reported.
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December 2024
College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, China.
A cost-effective industrial TiOSO solution was employed to fabricate visible light active sulfur-doped titanium dioxide (S-TiO) via a facile hydrothermal method. The effect of calcination temperature on morphology, particle size, crystallinity, and photocatalytic property of S-TiO was systematically investigated. Successful incorporation of sulfur into TiO was confirmed by carbon-sulfur analysis, X-ray photoelectron spectroscopy (XPS), and Energy dispersive spectrometer (EDS).
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Saha's Spectroscopy Laboratory, Department of Physics, University of Allahabad, Prayagraj, India.
The present study demonstrates the applicability of non-destructive and rapid spectroscopic techniques, specifically laser-induced fluorescence, ultraviolet-visible, and confocal micro-Raman spectroscopy, as non-invasive, eco-friendly, and robust multi-compound analytical methods for assessing biochemical changes in maize seedling leaves resulting from the treatment of aluminium oxide nanoparticles. The recorded fluorescence spectrum of the leaves shows that the treatment of different concentration of aluminium oxide nanoparticles decreases the chlorophyll content as observed by the increase in fluorescence emission intensity ratio (FIR = I/I). The analysis of ultraviolet-visible absorption measurements reveals that the amount of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid decrease for treated plants with respect to untreated seedlings.
View Article and Find Full Text PDFChemistry
December 2024
University of Pardubice: Univerzita Pardubice, Institute of Organic Chemistry and Technology, CZECHIA.
Differently substituted pyrrole-azo‑benzene molecular photoswitches were prepared in a straightforward synthetic way. Their fundamental properties were investigated by XRD analysis, differential scanning calorimetry, thermogravimetric analysis, cyclic voltammetry, UV‑Vis absorption spectroscopy, Hyper-Rayleigh Scattering, and NMR spectroscopy; the experimental results were further corroborated by DFT calculations. Thermal robustness, the HOMO/LUMO levels, and the absorption properties were altered mostly by substituting the N‑methylpyrrole moiety and further fine-tuned by modifying the benzene substituents.
View Article and Find Full Text PDFWater Res
December 2024
Institute for Advanced Membrane Technology (IAMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. Electronic address:
Calcium (Ca)-enhanced organic matter (OM) fouling of nanofiltration (NF) membranes leads to reduced flux during desalination and requires frequent cleaning. Fouling mechanisms are not fully understood, which limits the development of targeted fouling control methods. This study employed synchrotron-based X-ray fluorescence (XRF) and X-ray absorption near-edge structure (XANES) spectroscopy to quantify the spatial distribution and mass of Ca deposition as well as changes in the Ca coordination environment characteristic of specific fouling mechanisms, respectively.
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