An important question in solar physics is to what extent solar surface magnetism affects the solar irradiance. Previous attempts to answer this question have employed proxies of the magnetic field to reconstruct the irradiance and compare it with observations. Here we present the first model calculations of solar irradiance variations based on variations of the surface distribution of the solar...

small and medium size firms have major influence on job creation. some researchers, believe most of the new jobs are created in existed firms rather than newly established ones. growth management, could be the most important tactic for the firms future success. although it has many advantages for the firm, growth process faces some challenges. in this research, these challenges were identified,...

Previous studies have found that coronal loops have a nearly uniform thickness , which seems to disagree with the characteristic expansion of active region magnetic fields. This is one of the most intriguing enigmas in solar physics. We here report on the first comprehensive one-to-one comparison of observed loops with corresponding magnetic flux tubes obtained from cotemporal magnetic field ex...

Comparisons of solar magnetic-field measurements made in different spectral lines are very important, especially in those lines in which observations have a long history or(and) specific diagnostic significance. The spectral lines Fe i 523.3 nm and Fe i 525.0 nm belong to this class. Therefore, this study is devoted to a comprehensive analysis using new high-precision Stokesmeter full-disk obse...

We investigate the heating of the quiet corona by measuring the increase of coronal luminosity with the amount of magnetic flux in the underlying network at solar minimum when there were no active regions on the face of the Sun. The coronal luminosity is measured from Fe ix/x–Fe xii pairs of coronal images from SOHO/EIT, under the assumption that practically all of the coronal luminosity in our...

We analyze and interpret SOHO/MDI data on the variations of oscillation frequency changes between 1996 and 2004 focusing on differences between activity minimum and maximum of solar cycle 23. We study only the behavior of the centroid frequencies, which reflect changes averaged over spherical surfaces. Both the f-mode and p-mode frequencies are correlated with general measures of the sun’s magn...

We report the observation of one-arm spiral waves and of turbulence states in a nematic slab subjected to an external forcing These one-arm spiral waves constitute a close analog to the spiral waves observed m chemical and biological excitable media. Those results were obtained by adding a small vertical magnetic field on the experimental apparatus described m iii, in which double-arm spiral wa...