Context. The new generation of extreme-ultraviolet (EUV) imagers onboard missions such as the Solar Dynamics Observatory (SDO) and Solar Orbiter (SO) will provide the most accurate spatial measurements of post-flare coronal loop oscillations yet. The amplitude profiles of these loop oscillations contain important information about plasma fine structure in the corona. Aims. We show that the posi...

Oscillations of magnetic structures in the solar corona have often been interpreted in terms of magnetohydrodynamic waves. We study the adiabatic magnetoacoustic modes of a prominence plasma slab with a uniform longitudinal magnetic field, surrounded by a prominence-corona transition region (PCTR) and a coronal medium. Considering linear small-amplitude oscillations, the dispersion relation for...

The formation of negative ions produced in a negative point-to-plane corona discharge fed by a Ar/N2/CH4 gas mixture has been studied using mass spectrometry. The measurements were carried out in flowing regime at ambient temperature and a reduced pressure of 460 mbar. The CN− anion has been found to be the most dominant negative ion in the discharge and is believed to be the precursor of heavi...

We develop a theoretical model that explains the formation of hot coronae around strongly magnetized neutron stars — magnetars. The starquakes of a magnetar shear its external magnetic field, which becomes non-potential and is threaded by an electric current. Once twisted, the magnetosphere cannot untwist immediately because of its self-induction. The self-induction electric field lifts particl...

We present a method for deriving a twoÈthermal-component approximation to the di†erential emission measure distribution of plasma in the SunÏs corona in the temperature range to which the ExtremeUltraviolet Imaging Telescope (EIT) on the Solar and Heliospheric Observatory (SOHO) spacecraft is sensitive. EIT takes high-resolution full-disk coronal images in three of its four optimized channels b...

We highlight 10 key aspects of coronal heating that must be understood before we can consider the problem to be solved. (1) All coronal heating is impulsive. (2) The details of coronal heating matter. (3) The corona is filled with elemental magnetic stands. (4) The corona is densely populated with current sheets. (5) The strands must reconnect to prevent an infinite build-up of stress. (6) Nano...

The existence of a trypsin-like enzyme (TLE) in acrosomes ofepididymal spermatozoa was confirmed and was further demonstrated to be present in acrosomes of ejaculated and capacitated spermatozoa. TLE rapidly removes the zona pellucida of the ovum. Extracts of acrosomes of ejaculated spermatozoa contain an inhibitor that is separated from the TLE by purification of the TLE. The inhibitor of TLE ...

A DC positive streamer discharge has been characterized by measuring current/voltage relation, ozone and NOx production. Due to its relevance in the field of indoor air treatment, the effect of humidity was examined. The goal of this research is to use the corona discharge reactor for the abatement of low levels of toluene from indoor air. Experiments proved that toluene (concentrationin = 0.5 ...

We present a model for the spontaneous onset of fast magnetic reconnection in a weakly collisional plasma, such as the solar corona. When a current layer of macroscopic width undergoes collisional (Sweet-Parker) reconnection, a narrow dissipation region forms around the X-line. This dissipation region naturally becomes narrower during the reconnection process as stronger magnetic fields are con...

In this study, the photospheric vector magnetograms obtained by Helioseismic and Magnetic Imager on-board the Solar Dynamics Observatory are used as boundary conditions for a CESE-MHD model to investigate some photosphere characteristics around the time of a confined flare in solar active region NOAA AR 11117. We report our attempt of characterizing a more realistic solar atmosphere by includin...