Radio spectrometers of the CALLISTO type to observe solar flares have been distributed to nine locations around the globe. The instruments observe automatically, their data is collected every day via internet and stored in a central data base. A public webinterface exists through which data can be browsed and retrieved. The nine instruments form a network called e-CALLISTO. It is still growing in the number of stations, as redundancy is desirable for full 24 h coverage of the solar radio emission in the meter and low decimeter band. The e-CALLISTO system has already proven to be a valuable new tool for monitoring solar activity and for space weather research.

Shape-controlled Pt nanoparticles (cubic, tetrahedral, and cuboctahedral) are synthesized using stabilizers and capping agents. The nanoparticles are cleaned thoroughly and electrochemically characterized in acidic (0.5 M H2SO4 and 0.1 M HClO4) and alkaline (0.1 M NaOH) electrolytes, and their features are compared to that of polycrystalline Pt. Even with less than 100% shape-selectivity and with the truncation at the edges and corners as shown by the ex-situ TEM analysis, the voltammetric features of the shape-controlled nanoparticles correlate very well with that of the respective single-crystal surfaces, particularly the voltammograms of shape-controlled nanoparticles of relatively larger size. Shape-controlled nanoparticles of smaller size show somewhat higher contributions from the other orientations as well because of the unavoidable contribution from the truncation at the edges and corners. The Cu stripping voltammograms qualitatively correlate with the TEM analysis and the voltammograms. The fractions of low-index crystallographic orientations are estimated through the irreversible adsorption of Ge and Bi. Pt-nanocubes with dominant {100} facets are the most active toward oxygen reduction reaction (ORR) in strongly adsorbing H2SO4 electrolytes, while Pt-tetrahedral with dominant {111} facets is the most active in 0.1 M HClO4 and 0.1 M NaOH electrolytes. The difference in ORR activity is attributed to both the structure-sensitivity of the catalyst and the inhibiting effect of the anions present in the electrolytes. Moreover, the percentage of peroxide generation is 1.5-5% in weakly adsorbing (0.1 M HClO4) electrolytes and 5-12% in strongly adsorbing (0.5 M H2SO4 and 0.1 M NaOH) electrolytes.

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We report observations of the high frequency type II radio burst (≈430–30 MHz) that occurred in the solar corona on 2015 November 4. The drift rate of the burst, estimated close to the start frequency of its fundamental component (≈215 MHz), is unusually high (≈2 MHz s−1). Our analysis shows that the estimated speed of the magnetohydrodynamic shock driver of the burst varies with time. The peak speed and acceleration are very large, and , respectively. There is spatio-temporal correlation between the type II burst and the associated coronal mass ejection (CME) in the whitelight and extreme-ultraviolet images. The time profile of the shock speed and the light curve of the associated soft X-ray flare correlate well. These results indicate that in the present case, (i) the magnetohydrodynamic shock responsible for the high frequency coronal type II burst is driven by the CME and (ii) the time profile of the type II burst shock speed represents the near-Sun kinematics of the CME.