The growth rate and maximum value of electric field inside the thundercloud of finite dimensions are calculated incorporating the effect of positive space charge produced by corona at the ground surface. Our theoretical findings reveal that the transport of corona space charge increases significantly electric dipole moment already existing in thunderclouds of moderate heights and is partly resp...

The Sun's outer atmosphere, or corona, is heated to millions of degrees, considerably hotter than its surface or photosphere. Explanations for this enigma typically invoke the deposition in the corona of nonthermal energy generated by magnetoconvection. However, the coronal heating mechanism remains unknown. We used observations from the Solar Dynamics Observatory and the Hinode solar physics m...

Following previous investigations by Giordano and Mancuso [1] and Mancuso and Giordano [2,3] on the differential rotation of the solar corona as obtained through the analysis of the intensity time series of the O VI 1032 Å spectral line observed by the UVCS/SOHO telescope during solar cycle 23, we analysed the possible influence of projection effects of extended coronal structures on the observ...

Using Zeeman observations of the H30α recombi-nation line maser transition at 1.3 mm we have detected a magnetic field which is associated with the corona of the circum-stellar disk of MWC 349. At a radial distance of 40 a.u., where the H30α maser is located, the line–of–sight component of the field is approximately parallel to the plane of this edge–on disk, and its average strength is 22 mG. ...

Cutting-edge observations with the 1.6-meter telescope at Big Bear Solar Observatory (BBSO) in California have taken research into the activity of the Sun to new levels of understanding of the structure and evolution of the solar atmosphere at high-resolution spatial and temporal scales. On August 7, 2013 the NST observed active region NOAA 11810 in photospheric and chromospheric wavelengths. T...

Background: Given the importance of maintaining the mental health of workers, the present study was conducted to determine the effect of the individual factors on hypochondriasis and job stress under the corona epidemic condition in a company.    Methods: This cross-sectional study was performed on 275 workers in 2020 in one of the industries in southern Iran. To gather the data, demographic, ...

For two graphs $mathrm{G}$ and $mathrm{H}$ with $n$ and $m$ vertices, the corona $mathrm{G}circmathrm{H}$ of $mathrm{G}$ and $mathrm{H}$ is the graph obtained by taking one copy of $mathrm{G}$ and $n$ copies of $mathrm{H}$ and then joining the $i^{th}$ vertex of $mathrm{G}$ to every vertex in the $i^{th}$ copy of $mathrm{H}$. The neighborhood corona $mathrm{G}starmathrm{H}$ of $mathrm{G}$ and $...

Estimating the structure, or density distribution, of the solar corona from a set of 2D white light images made by coronagraphs is a critical challenge in coronal physics. This work describes new data analysis procedures which are used to create global maps of the coronal structure at heights where the corona becomes approximately radial (≥3R ). The technique, which is named Qualitative Solar R...

This paper reports a study on the inception condition of positive corona discharges around thundercloud hydrometeors that are simulated as a spherical point electrode. The corona inception from the hydrometeor is investigated using a model developed by Naidis (2005), which suggests that the discharge becomes self-sustaining when the number of ionizing photons produced by all secondary electron ...