The steady-state structure of a disc with a corona is analyzed when the vertical component of the gravitational force due to the self-gravity of the disc is considered. For the energy exchange between the disc and the corona, we assume a fraction f of the dissipated energy inside the accretion disc is transported to the corona via the magnetic tubes. Analytical solutions corresponding to a pres...

Hypercritical accretion flows onto stellar mass black holes (BHs) are commonly considered as a promising model of central engines of gamma-ray bursts (GRBs). In this model a certain fraction of gravitational binding energy of accreting matter is deposited to the energy of relativistic jets via neutrino annihilation and/or magnetic fields. However, some recent studies have indicated that the ene...

We investigate the escape of species from Io's atmosphere using a steady-state model of Io's exospheric corona and its interaction with the Io plasma torus. The corona is assumed to be spherically symmetric with the radial density and compositional structure determined by the gas kinetic temperature, critical level radius, and mixing ratios of the component species. Thermal and nonthermal escap...

‎‎let $g=(v,e)$ be a simple graph‎. ‎an edge labeling $f:eto {0,1}$ induces a vertex labeling $f^+:vtoz_2$ defined by $f^+(v)equiv sumlimits_{uvin e} f(uv)pmod{2}$ for each $v in v$‎, ‎where $z_2={0,1}$ is the additive group of order 2‎. ‎for $iin{0,1}$‎, ‎let‎ ‎$e_f(i)=|f^{-1}(i)|$ and $v_f(i)=|(f^+)^{-1}(i)|$‎. ‎a labeling $f$ is called edge-friendly if‎ ‎$|e_f(1)-e_f(0)|le 1$‎. ‎$i_f(g)=v_f(...

امروزه استفاده از محرک­های پلاسمایی جریان متناوب نسبت به جریان مستقیم، جهت کنترل فعال جریان، متداول­تر بوده و تقریبأ هیچ کار تحقیقی بر روی پلاسمای جریان مستقیم انجام نگرفته است. در این مقاله با استفاده از یک منبع تغذیه جریان مستقیم و هندسه های گوناگون، خصوصیات پلاسما در هر دو حالت corona و dbd (dielectric barrier discharge)  مورد مطالعه قرار گرفت. با استفاده از نتایج این پژوهش مشخص شد که جریان ...

Microresonators have been utilized to construct optical interconnection networks. One of the drawbacks of these microresonators is that they suffer from intrinsic crosstalk noise and power loss, resulting in Signal-to-Noise Ratio (SNR) reduc-tion and system performance degradation at the network level. The novel contribution of this paper is to systematically study the worst-case crosstalk nois...

‎let $g=(v(g),e(g))$ be a simple connected graph with vertex set $v(g)$ and edge‎ ‎set $e(g)$‎. ‎the (first) edge-hyper wiener index of the graph $g$ is defined as‎: ‎$$ww_{e}(g)=sum_{{f,g}subseteq e(g)}(d_{e}(f,g|g)+d_{e}^{2}(f,g|g))=frac{1}{2}sum_{fin e(g)}(d_{e}(f|g)+d^{2}_{e}(f|g)),$$‎ ‎where $d_{e}(f,g|g)$ denotes the distance between the edges $f=xy$ and $g=uv$ in $e(g)$ and $d_{e}(f|g)=s...

We revisit in more detail a model for element abundance fractionation in the solar chromosphere, that gives rise to the “FIP Effect” in the solar corona and wind. Elements with first ionization potential below about 10 eV, i.e. those that are predominantly ionized in the chromosphere, are enriched in the corona by a factor 3-4. We model the propagation of Alfvén waves through the chromosphere u...