The behavior of an aqueous-dominant multicomponent cometary model is examined at high doses of ionizing radiation. The system is composed of a water mixture of HCN (0.2 mol dm-3), CH3CN (0.04 mol dm-3), C2H5CN (0.02 mol dm-3), CH3OH (0.12 mol dm-3) and HCO2H (0.01 mol dm-3. It was exposed to gamma rays at doses up to 18.5 MGy. The chemical kinetic database used in the computer treatment of experimental data consists of 79 reactions. A complex mixture of products has been synthesized: gases, amino acids, carboxylic acids and polymeric material. The results suggest that the pristine material in cometary nuclei may have been chemically altered by the action of cosmic rays and embedded radionuclides.
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http://dx.doi.org/10.1016/0273-1177(92)90155-q | DOI Listing |
Sci Rep
January 2025
Department of Chemistry, Devchand College, Arjunnagar, Kolhapur, MH, 591237, India.
Acoustical properties are essential for understanding the molecular interactions in fluids, as they influence the physicochemical behavior of liquids and determine their suitability for diverse applications. This study investigated the acoustical parameters of silver nanoparticles (Ag NPs), reduced graphene oxide (rGO), and Ag/rGO nanocomposite nanofluids at varying concentrations. Ag NPs and Ag/rGO nanocomposites were synthesized via a Bos taurus indicus (BTI) metabolic waste-assisted method and characterized using advanced techniques, including XRD, TEM, Raman, DLS, zeta potential, and XPS.
View Article and Find Full Text PDFAnal Sci
January 2025
Graduate School of Pharmaceutical Sciences, Tokushima University, 1-78-1 Shomachi, Tokushima, 770-8505, Japan.
A digital-movie-based flow colorimetry for pH measurement using a universal indicator has been applied to the end point detection of acid-base titrations. A two-channel flow system of feedback-based flow ratiometry, primarily consisting of two peristaltic pumps, a digital microscope-based detector, and a laptop computer, was constructed; a Visual Basic.NET program written in-house was used for automating the analytical processes.
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January 2025
Markanda National College, District-Kurukshetra, Shahabad (M), 136135, Haryana, India.
Pyrazole derivatives are aromatic heterocyclic compounds endowed with multifaceted applications. In the present study 1,3,4-trisubstituted pyrazoles derivatives have been synthesized for the purpose of studying their physical properties and their characterization was done by FTIR, H NMR and C NMR spectroscopic technique. The measurement of densities (ρ) and viscosities (η) of solutions of substituted pyrazole derivative in polar aprotic solvent i.
View Article and Find Full Text PDFChem Sci
December 2024
Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
Phosphorescent gold(iii) complexes possess long-lived emissive excited states, making them ideal for use as molecular sensors and photosensitizers for organic transformations. Literature reports indicate that gold(iii) emitters exhibit good catalytic activity in homogeneous photochemical reactions. Heterogeneous metal-organic framework (MOF)-supported gold(iii) photocatalysts are considered to show high recyclability in photochemical reactions and potentially provide new selectivities.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Department of Chemical, Environmental and Materials Engineering, Higher Polytechnical School of University of Jaén, Avda. de la Universidad s/n, 23700 Linares, Spain.
A sequential valorization process of sunflower stalks was carried out using nitric acid (0.1-2 mol dm) as a hydrolytic agent and fermenting the hydrolysate of higher sugar concentration in the presence of the non-conventional yeast . Values reached for ethanol yield (0.
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