Modelling of Quiet Sun Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 169-176
Author(s):  
S. Serio
Keyword(s):  
Thermal Stability ◽  
Heat Conduction ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Thermal Stratification ◽  
Recent Progress ◽  
Coronal Loops ◽  
Dynamic Heating ◽  
Thermal Stability Of ◽  
Coronal Structures

AbstractThe 1978 paper by Rosner et al. has set the basis for a new way of understanding thermal stratification in the solar corona, taking into account the constraints of magnetic fields on heat conduction. This paper will review recent progress in modelling of coronal loops, and in particular the effects of deviations from Spitzer conductivity, stationary siphon flows and shocks, thermal stability of the transition region, and possible diagnostics of dynamic heating of the coronal plasma.

Calculated Coronal Magnetic Fields and Their Comparison with the Coronal Structures as Observed during Five Solar Eclipses

1994 ◽  
Vol 144 ◽  
pp. 559-564
Author(s):  
P. Ambrož ◽  
J. Sýkora
Keyword(s):  
Magnetic Field ◽  
Solar Cycle ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Coronal Magnetic Field ◽  
Coronal Magnetic Fields ◽  
Solar Eclipses ◽  
Coronal Structures

AbstractWe were successful in observing the solar corona during five solar eclipses (1973-1991). For the eclipse days the coronal magnetic field was calculated by extrapolation from the photosphere. Comparison of the observed and calculated coronal structures is carried out and some peculiarities of this comparison, related to the different phases of the solar cycle, are presented.

Study of Thermal Stability of Magnesium Alloys

2013 ◽  
Vol 690-693 ◽  
pp. 74-77
Author(s):  
Zuzana Turnova ◽  
Tomas Chrebet ◽  
Ivana Turekova ◽  
Karol Balog
Keyword(s):  
Thermal Stability ◽  
Chemical Composition ◽  
Magnesium Alloys ◽  
Ignition Temperature ◽  
Structural Materials ◽  
Mg Alloys ◽  
Muffle Furnace ◽  
Dynamic Heating ◽  
Thermal Stability Of

Today, magnesium (Mg) alloys are recognized alternatives to iron and aluminum to reduce the weight of structural materials. This contribution was performed to provide information on the flammability of magnesium alloys through investigation of the ignition temperature of selected Mg alloys. The test was performed in a muffle furnace with dynamic heating program. Also were performed tests of chemical composition of studied specimens.

scholarly journals A Thermal Catastrophe in a Resonantly Heated Coronal Loop

1983 ◽  
Vol 102 ◽  
pp. 397-400
Author(s):  
P.C.H. Martens ◽  
M. Kuperus
Keyword(s):  
Magnetic Field ◽  
Thermal Stability ◽  
Coronal Loop ◽  
Coronal Loops ◽  
Natural Explanation ◽  
X Ray ◽  
Magnetic Field Topology ◽  
Coronal Rain ◽  
The Magnetic Field ◽  
Thermal Stability Of

A theory for the thermal stability of hot coronal loops is presented, which is based on the resonant electrodynamic heating theory of Ionson (1982) and the evaporation/condensation scenario of Krall and Antiochos (1980). The theory predicts that gradual changes in the length of a loop or in its magnetic field strength can trigger catastrophic changes in the X-ray visibility of the loop, without the need for a change in the magnetic field topology.A natural explanation is thereby given for the observations of X-ray brightenings in loops and loop evacuations with coronal rain.

Experimental and Numerical Analyses of Effect of Thermal Stability of Lubricants on Heatstreaks in Cold Rolling of Stainless Steel

1993 ◽  
Vol 115 (3) ◽  
pp. 532-537 ◽  
Author(s):  
H. Yamamoto ◽  
T. Shiraishi ◽  
M. Ataka ◽  
Y. Iwasaki
Keyword(s):  
Thermal Stability ◽  
Stainless Steel ◽  
Heat Conduction ◽  
Numerical Analysis ◽  
Cold Rolling ◽  
Interface Temperature ◽  
Analysis Model ◽  
Rolled Material ◽  
Synthetic Ester ◽  
Thermal Stability Of

The numerical analysis model of temperature in a roll and a rolled material was first derived by solving the equations of heat conduction. Next, the occurrence limits of heatstreaks for reduction in thickness and interface temperature in a roll bite were evaluated experimentally and numerically in cold rolling experiments of stainless steel (SUS430) with two kinds of lubricants. Also, the thermal stability of two lubricants was measured by thermal balance experiments. Consequently, the limit of interface temperature due to heatstreaks calculated numerically is almost constant in a lubricant, which suggests that an outbreak of heatstreaks is mostly dependent on the thermal stability of lubricant. Also, larger quantity of synthetic ester is considered to give higher heatstreak resistance in cold rolling of stainless steel.

The thermal stability of coronal loops numerical simulations

Solar Physics ◽  
1991 ◽  
Vol 132 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Y. Mok ◽  
D. D. Schnack ◽  
G. Van Hoven
Keyword(s):  
Thermal Stability ◽  
Numerical Simulations ◽  
Coronal Loops ◽  
Thermal Stability Of

Thermal stability of static coronal loops. I - Effects of boundary conditions

1985 ◽  
Vol 298 ◽  
pp. 876 ◽  
Author(s):  
S. K. Antiochos ◽  
E. C. Shoub ◽  
C.-H. An ◽  
A. G. Emslie
Keyword(s):  
Thermal Stability ◽  
Boundary Conditions ◽  
Coronal Loops ◽  
Thermal Stability Of

scholarly journals Chromospheric and Coronal Heating Due to the Radiation and Collisional Damping of Fast Magnetosonic Surface Waves

1987 ◽  
Vol 42 (12) ◽  
pp. 1443-1450 ◽  
Author(s):  
W. Sahyouni ◽  
Zh. Kiss’ovski ◽  
I. Zhelyazkov
Keyword(s):  
Magnetic Field ◽  
Heat Conduction ◽  
Solar Corona ◽  
Surface Waves ◽  
Solar Atmosphere ◽  
Wave Energy ◽  
Coronal Loops ◽  
Electron Heat ◽  
Background Magnetic Field ◽  
Collisional Damping

We study the propagation of surface/pseudosurface modes in the structured solar atmosphere assuming that the surface waves m ay be able to heat the chromosphere and corona. The wave energy can be dissipated by radiation, ion viscosity, and electron heat conduction . For the solar corona, it is found that the pseudosurface waves, trapped in the coronal loops, dissipate efficiently only if their periods are longer than 200 seconds and only if the background magnetic field is smaller than 5 gauss.

scholarly journals The Solar Corona

1980 ◽  
Vol 5 ◽  
pp. 335-341
Author(s):  
Claudio Chiuderi
Keyword(s):  
Magnetic Fields ◽  
Solar Corona ◽  
Coronal Structures

AbstractRecent observations from space have shown that the solar corona is spatially a very structured medium and temporally a very dynamic one. The consequent changes in the current theoretical ideas about coronal physics are reviewed. The role of the magnetic fields in shaping and heating the coronal structures is especially underlined.

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