Correction for 'Theoretical study on the mechanisms of formation of primal carbon clusters and nanoparticles in space' by Dobromir A. Kalchevski , , 2024, https://doi.org/10.
View Article and Find Full Text PDFWe present a theoretical study of assembling clusters and nanoparticles in space from primordial aggregations of unbound carbon atoms. Geometry optimization and SCC-DFTB dynamics methods are employed to predict carbon clusters, their time evolution and stability. The initial density of the aggregates is found to be of primary importance for the structure of the clusters.
View Article and Find Full Text PDFDifferent nano-sized phases were synthesized using chemical vapor deposition (CVD) processes. The deposition took place on {001} Si substrates at about 1150-1160 °C. The carbon source was thermally decomposed acetone (CH)CO in a main gas flow of argon.
View Article and Find Full Text PDFThe chemical interactions of two types of graphite and two types of carbon black (CB) with acetone, toluene, and phenol were studied in order to evaluate the influence of chemical treatment on the structure and morphology of the carbon phases. The experimental treatment of carbon phases was carried out at room temperature for 1 hour. The chemical and phase composition were studied by x-ray photoelectron (XP) and Raman spectroscopies, while the morphology and structure were determined by powder x-ray diffraction, as well as transmission electron microscopy techniques.
View Article and Find Full Text PDFThe present study investigates the possibility of obtaining graphene-like phases (defected graphene, graphene oxide, and reduced graphene oxide) as fine suspensions by applying a novel pulsed laser ablation (PLA) approach in flow mode. Two types of suspensions of microcrystalline graphite in aqueous suspensions and two types of microcrystalline graphite in suspensions of 6% hydrogen peroxide solution were irradiated in a quartz tube through which they flow. The third (λ = 355 nm) and fourth harmonics (λ = 266 nm) of an Nd:YAG laser system (15 ns pulse duration and 10 Hz pulse repetition rate) were used.
View Article and Find Full Text PDFThe interactions between Na or Mg ions with different parts of single-stranded RNA molecules, namely, the oxygen atoms from the phosphate groups or the guanine base, in water solution have been studied using first-principles molecular dynamics. Sodium ions were found to be much more mobile than Mg ions and readily underwent transitions between a state directly bonded to RNA oxygen atoms and a completely solvated state. The inner solvation shell of Na ions fluctuated stochastically at a femtosecond timescale coordinating on average 5 oxygen atoms for bonded Na ions and 5.
View Article and Find Full Text PDFAlkaline and alkaline earth ions, namely Na+, K+, Mg2+ and Ca2+, are critical for the stability, proper folding and functioning of RNA. Moreover, those metal ions help to facilitate macromolecular interactions as well as the formation of supramolecular structures (e.g.
View Article and Find Full Text PDFSingle crystals of the mixed valence compound Pb₃Ni₁.₅Mn₅.₅O₁₅ were successfully grown.
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