The Role of Magnetic Fields in the Origin and Structure of Planetary Nebulae

Planetary Nebulae ◽

Ionized Gas ◽

Symmetrical Structure ◽

Image Position ◽

That the characteristic, quasi-symmetrical structure of planetary nebulae may result from the presence of imbedded magnetic fields has undoubtedly occurred to many astronomers. Gurzadian (1962), for example, employed the widely used equation where p is the pressure of the ionized gas and H the magnetic-field intensity. This equation specifies that the sum of the gas and magnetic pressures should be constant for a given value of the radius.

The role of the magnetic field intensity and geometry in the type III burst generation

Solar Physics ◽

10.1007/bf00156777 ◽

1990 ◽

Vol 130 (1-2) ◽

pp. 31-37 ◽

Cited By ~ 6

Author(s):

P. Zlobec ◽

V. Ruždjak ◽

B. Vršnak ◽

M. Karlický ◽

M. Messerotti

Keyword(s):

Magnetic Field ◽

Field Intensity ◽

Type Iii ◽

Magnetic fields in Proto Planetary Nebulae

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314002592 ◽

2013 ◽

Vol 9 (S302) ◽

pp. 398-399

Author(s):

L. Sabin ◽

Q. Zhang ◽

A. A. Zijlstra ◽

N. A. Patel ◽

R. Vázquez ◽

...

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Planetary Nebulae ◽

Point Of View ◽

Late Type ◽

Grain Alignment ◽

Observational Point ◽

AbstractThe role of magnetic field in late type stars such as proto-planetary and planetary nebulae (PPNe/PNe), is poorly known from an observational point of view. We present submillimetric observations realized with the Submillimeter Array (SMA) which unveil the dust continuum polarization in the envelopes of two well known PPNe: CRL 618 and OH 231.8+4.2. Assuming the current grain alignment theory, we were then able to trace the geometry of the magnetic field.

Correlation between Ca plages and longitudinal magnetic fields of the CSSAR active regions

Symposium - International Astronomical Union ◽

10.1017/s0074180900021744 ◽

1968 ◽

Vol 35 ◽

pp. 338-345 ◽

Author(s):

V. Bumba ◽

G. Godoli

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Field Intensity ◽

Solar Disk ◽

Active Regions ◽

The Magnetic Field ◽

Magnetic Inclusions

The shapes of K2,3,2 Ca plages and longitudinal magnetic fields are compared for CSSAR active regions during their first transit on the solar disk.The bipolar magnetic regions follow the Hale polarity law.Often the region of inversion of the magnetic field corresponds to a gap in the Ca plage structure.Bright patches of plages may coincide with magnetic inclusions, magnetic hills, and occasionally also with regions of inversion of the magnetic field. The outline of Ca plages follow well the isogauss of 20–40 oersted.Histograms of the distances of individual magnetic field intensity peaks do not only correspond to the geometry of the supergranular network but also seem to indicate a difference in the organization of these peaks between the leading and following polarities.

Estimation of informative and background signals ratio in the registration of magnetic fields of surface defects by magnetic measuring transducers

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2020-5-43-49 ◽

2020 ◽

pp. 43-49

Author(s):

Yuriy L. Nikolaev ◽

Elina F. Akhmetshina ◽

Aleksey A. Samorukov ◽

Aleksandra V. Chernova

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Field Intensity ◽

Output Signal ◽

Background Ratio ◽

Estimated Parameters ◽

Magnetic Measuring ◽

Background Magnetic Field ◽

Authors propose algorithms for quantitative ratio determining of informative and background components of the output signal of magnetic measuring transducers, used as a means of recording and measuring the parameters of locally distributed magnetic fields that occur over defective surface areas of the tested object in an applied permanent magnetic field. The method of separating the informative and background components based on the summation property and the deterministic nature of the distributions of the magnetic field intensity of the defect and the background magnetic field along the coordinate axis parallel to the controlled surface, and analysis of the topography of the distribution of magnetic field intensity is described. The approach to selection and experimental determination of estimated parameters characterizing the levels of informative and background signals is justified. Authors give the formulas for calculating the signal-to-background ratio based on the measured values of the estimated parameters applied to single magnet-static, differential magnet-static and differentiating magnetic measuring transducers taking into account the orientation direction (normal, tangential) of their sensitivity axis. The signal-to-background ratio calculation results are presented using an example of an analysis of the magnetic measuring transducers output signal when registering the distribution of the magnetic field intensity over the surface of a control sample with artificial defects of a given size. The comparative analysis of considered magnetic measuring transducers according to signal-to-background ratio is carried out. General recommendations to increase the value of the signal-to-background ratio parameter are given.

Variation of Surface Tension of Water in High Magnetic Field

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.2279 ◽

2013 ◽

Vol 750-752 ◽

pp. 2279-2282 ◽

Cited By ~ 2

Author(s):

Long Chen ◽

Chuan Jun Li ◽

Zhong Ming Ren

Keyword(s):

Magnetic Field ◽

Surface Tension ◽

Magnetic Fields ◽

Hydrogen Bonds ◽

High Magnetic Field ◽

Field Intensity ◽

High Magnetic Fields ◽

The surface tension of water in high magnetic fields up to 10T was investigated with aid of the high-magnetic-field tensiometer (HMFT). It was found that the surface tension of water linearly varied with the magnetic field intensity and increased by 0.48mN/m or 0.65% in 10T. The increase of the surface tension of water could be attributed to the increase in the number and stabilization of the hydrogen bonds in the magnetic field.

Tunable amplified spontaneous emission based on liquid magnetically responsive photonic crystals

Journal of Materials Chemistry C ◽

10.1039/c8tc05763j ◽

2019 ◽

Vol 7 (13) ◽

pp. 3740-3743 ◽

Author(s):

Ying Li ◽

Yue Long ◽

Guoqiang Yang ◽

Chen-Ho Tung ◽

Kai Song

Keyword(s):

Magnetic Field ◽

Photonic Crystals ◽

Spontaneous Emission ◽

Field Intensity ◽

Amplified Spontaneous Emission ◽

The wavelength of amplified spontaneous emission based on liquid magnetically responsive photonic crystals can be tuned by simply changing the magnetic field intensity.

Magnetic Fields and Disks in Star-forming Regions

Publications of the Astronomical Society of Australia ◽

10.1017/s1323358000025777 ◽

1993 ◽

Vol 10 (3) ◽

pp. 247-249 ◽

Cited By ~ 5

Author(s):

C.M. Wright ◽

D.K. Aitken ◽

C.H. Smith ◽

P.F. Roche

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Transverse Component ◽

Young Stellar Objects ◽

Stellar Objects ◽

Star Forming ◽

Star Forming Regions ◽

Molecular Outflow ◽

AbstractThe star-formation process is an outstanding and largely unsolved problem in astrophysics. The role of magnetic fields is unclear but is widely considered to be important at all stages of protostellar evolution, from cloud collapse to ZAMS. For example, in some hydromagnetic models, the field may assist in removing angular momentum, thereby driving accretion and perhaps bipolar outflows.Spectropolarimetry between 8 and 13μm provides information on the direction of the transverse component of a magnetic field through the alignment of dust grains. We present results of 8–13μm spectropolarimetric observations of a number of bipolar molecular outflow sources, and compare the field directions observed with the axes of the outflows and putative disk-like structures observed to be associated with some of the objects. There is a strong correlation, though so far with limited statistics, between the magnetic field and disk orientations. We compare our results with magnetic field configurations predicted by current models for hydromagnetically driven winds from the disks around Young Stellar Objects (YSOs). Our results appear to argue against the Pudritz and Norman model and instead seem to support the Uchida and Shibata model.

A Novel Method for Improving Low-Temperature Flotation Performance of Nonpolar Oil in the Molybdenite Flotation

Minerals ◽

10.3390/min9100609 ◽

2019 ◽

Vol 9 (10) ◽

pp. 609 ◽

Author(s):

Wan ◽

Qu ◽

Li ◽

He ◽

Bu ◽

...

Keyword(s):

Magnetic Field ◽

Surface Tension ◽

Low Temperature ◽

Interfacial Tension ◽

Field Intensity ◽

Maximum Surface ◽

Flotation Recovery ◽

Flotation Performance ◽

Nonpolar hydrocarbon oil (NHO) is one of the most extensively used collectors in the flotation of molybdenite due to its excellent selectivity. However, NHO has low sensibility at pulp temperature. At low temperatures (<283 K), although more kerosene is used, the recovery of molybdenite flotation is still lower than at room temperature. In this study, magnetizing treatment, which is an efficient, low-cost, innovative, and environmentally friendly emulsification method, was used to improve the flotation performance of NHO in low-temperature molybdenite flotation. The test results showed that, compared with unmagnetized kerosene (UMK), the optimum dosage of magnetized kerosene (MK) could be reduced by 11% at 298 K. At the same dosage of kerosene, the flotation recovery of MK was 3% higher than UMK at 278 K. The surface tension measurement results showed that the surface tension of MK rose periodically as the magnetic field intensity increased, and there was a maximum surface tension within each period. Further, the magnetic field intensity had the maximum flotation recovery of molybdenite at the maximum surface tension of MK. Combined with the analysis based on the Girifalco–Good theory and the static drop volume method of interfacial tension, the interfacial tension of kerosene–water was shown to decrease with the increase of the surface tension of kerosene. This finding indicates that the dispersibility of kerosene in pulp could be improved by reducing the size of oil droplets, thereby improving the molybdenite flotation recovery of kerosene at low-temperature pulp. It is helpful to improve the flotation recovery of molybdenite using NHO as a collector for low-temperature pulp (<283 K).

Oscillatory convection in strong magnetic fields and origin of active regions

Symposium - International Astronomical Union ◽

10.1017/s0074180900021410 ◽

1968 ◽

Vol 35 ◽

pp. 127-130 ◽

Author(s):

S. I. Syrovatsky ◽

Y. D. Zhugzhda

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Active Regions ◽

Oscillatory Convection ◽

Strong Magnetic Fields ◽

Various Boundary Conditions ◽

Convective Cells ◽

The Magnetic Field ◽

Polytropic Atmosphere

The convection in a compressible inhomogeneous conducting fluid in the presence of a vertical uniform magnetic field has been studied. It is shown that a new mode of oscillatory convection occurs, which exists in arbitrarily strong magnetic fields. The convective cells are stretched along the magnetic field, their horizontal dimensions are determined by radiative cooling. Criteria for convective instability in a polytropic atmosphere are obtained for various boundary conditions in the case when the Alfvén velocity is higher compared with the velocity of sound.The role of oscillatory convection in the origin of sunspots and active regions is discussed.

Viscosity of Potassium Dihydrogen Phosphate Aqueous Solution within Magnetic Field

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.1783 ◽

2017 ◽

Vol 898 ◽

pp. 1783-1786

Author(s):

Lei Zhang ◽

Yi Su ◽

Yu Lin Wu ◽

Yao Liu ◽

Yong Wang ◽

...

Keyword(s):

Magnetic Field ◽

Aqueous Solution ◽

Field Intensity ◽

Extreme Values ◽

Potassium Dihydrogen Phosphate ◽

Experimental Results ◽

Dihydrogen Phosphate ◽

Potassium Dihydrogen ◽

The viscosity of potassium dihydrogen phosphate, KH2PO4 (KDP), aqueous solution within magnetic field was studied. Experimental results showed that, the viscosity of saturated KDP solution exhibited multiple extreme values when the magnetic field intensity increased from 0 Gs to 2250 Gs. Influences of the magnetic field intensity on the viscosity of KDP solution were very complicated. It’s concerned with the temperature and the concentration of solution. As the KDP was produced from aqueous solution within magnetic field, the temperature and the concentration of solution also needed to be carefully controlled. Magnetic field with intensity values of 300 Gs, 600 Gs and 1800 Gs, all have the strong effects on the structures of KDP aqueous solution.