Dynamism in the solar core

Recent results of a mixed shell model heated asymmetrically by transient increases in nuclear burning indicate the transient generation of small hot spots inside the Sun somewhere between 0.1 and 0.2 solar radii. These hot bubbles are followed by a nonlinear differential equation system with finite amplitude non-homologous perturbations which is solved in a solar model. Our results show the possibility of a direct connection between the dynamic phenomena of the solar core and the atmospheric activity. Namely, an initial heating about DQ_0 ~ 10^{31}-10^{37} ergs can be enough for a bubble to reach the outer convective zone. Our calculations show that a hot bubble can arrive into subphotospheric regions with DQ_final ~ 10^{28} - 10^{34} ergs with a high speed, up to 10 km s-1, approaching the local sound speed. We point out that the developing sonic boom transforms the shock front into accelerated particle beam injected upwards into the top of loop carried out by the hot bubble above its forefront traveling from the solar interior. As a result, a new perspective arises to explain flare energetics. We show that the particle beams generated by energetic deep-origin hot bubbles in the subphotospheric layers have masses, energies, and chemical compositions in the observed range of solar chromospheric and coronal flares. It is shown how the emergence of a hot bubble into subphotospheric regions offers a natural mechanism that can generate both the eruption leading to the flare and the observed coronal magnetic topology for reconnection. We show a list of long-standing problems of solar physics that our model explains. We present some predictions for observations, some of which are planned to be realized in the near future.Comment: 44 pages, 20 figure

Synthesis of carboxylated derivatives of poly(isobutylene-co-isoprene) by azide–alkyne “click” chemistry

The final publication is available at Springer via https://dx.doi.org/10.1038/s41428-018-0130-yThe synthesis of carboxylated derivatives of poly(isobutylene-co-isoprene) (isobutylene–isoprene rubber, IIR) with substitution levels ranging from 1 to 4 mol% and different spacer lengths was accomplished through azide–alkyne Huisgen cycloaddition. Azido-functionalized IIR was first prepared by reacting brominated IIR with sodium azide to full conversion in a 90:10 tetrahydrofuran/N,N-dimethylacetamide mixture. The click reaction of azido-functionalized IIR with acetylenic acids, which was carried out using the copper(I) bromide/N,N,N′,N″,N″-pentamethyldiethylenetriamine catalyst system in tetrahydrofuran, yielded carboxylated IIRs. The products were characterized by 1H NMR and FT-IR spectroscopy, and their molecular weight was determined by size exclusion chromatography analysis. The conversion to carboxylated groups reached up to 100% as determined by NMR spectroscopy but was highly dependent on the type of solvent and the amounts of catalysts and reactants used in the procedures.ARLANXEO Canada Inc.Natural Sciences and Engineering Research Council (NSERC) of Canad