scholarly journals The oscillating-cup viscometer placed in the magnetic field: the experiments under liquid gallium

2008 ◽  
Vol 98 (6) ◽  
pp. 062016 ◽  
Author(s):  
V P Beskachko ◽  
O A Golovnya ◽  
M B Khismatulin ◽  
A E Korenchenko
Keyword(s):  
Magnetic Field ◽  
Liquid Gallium ◽  
Oscillating Cup Viscometer ◽  
The Magnetic Field ◽  
Oscillating Cup

FeNbVB ALLOY PARTICLES SUSPENDED IN LIQUID GALLIUM: INVESTIGATING THE MAGNETIC PROPERTIES OF THE MR SUSPENSION

2011 ◽  
Vol 25 (07) ◽  
pp. 947-955 ◽  
Author(s):  
GJERGJ DODBIBA ◽  
KENJI ONO ◽  
HYUN SEO PARK ◽  
SEIJI MATSUO ◽  
TOYOHISA FUJITA
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Iron Alloy ◽  
Testing Temperature ◽  
Liquid Gallium ◽  
Temperature Sensitive ◽  
Prepared Powder ◽  
Alloy Particles ◽  
The Magnetic Field

A MR suspension was prepared by dispersing silica-coated iron alloy particles into a liquid gallium. In other words, the iron alloy particles of 30 to 50 nm in diameter were first prepared and then coated with silica. Next, the particles were then suspended in a liquid Ga (assay: 99.9999%). In addition, the magnetic properties of the synthesized particles and suspension under the influence of the magnetic field were investigated. One of the main findings of this study is that the prepared powder showed a temperature sensitive of magnetization within the testing temperature range of 293–353 K. The saturation magnetization of silica-coated FeNbVB particles was about 0.55 T, whereas the saturation magnetization (297 K) of the synthesized MR suspension was 0.019 T.

An Experimental Study of Magnetic Damping Effect on Temperature Gradient Induced Natural Convection in Liquid Gallium

2004 ◽  
Author(s):  
B. Xu ◽  
B. Q. Li ◽  
D. E. Stock
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Liquid Gallium ◽  
Horizontal Magnetic Field ◽  
Magnetic Damping ◽  
Damping Effect ◽  
Different Temperatures ◽  
Hot Film ◽  
The Magnetic Field ◽  
Good Agreement

The results of an experimental investigation of natural convection driven flow of liquid gallium are presented. The gallium contained by a rectangular box with two opposite ends held at different temperatures and is subject to a uniform horizontal magnetic field. The objective of this study was to examine the damping effect of a magnetic field on the natural convection in a liquid metal. A hot film anemometry was used to measure the velocity profile and a thermocouple was used to measure the temperature field. The hot-film probe was calibrated over a narrow range of temperatures in a rotating container fill with liquid gallium. The velocity and temperature profiles are compared with previous numerical simulations and reasonably good agreement was found. The damping effect of the external magnetic field was observed in both the temperature and the velocity profiles and found to increase as the strength of the magnetic field increases.

Liquid Metal Free Surface Motion Submerged in an AC Magnetic Field

2007 ◽  
Vol 561-565 ◽  
pp. 1071-1074
Author(s):  
Kazuhiko Iwai ◽  
Shigeo Asai
Keyword(s):  
Magnetic Field ◽  
Free Surface ◽  
Liquid Metal ◽  
Standing Wave ◽  
Skin Layer ◽  
Alternating Magnetic Field ◽  
Liquid Gallium ◽  
Field Frequency ◽  
Surface Motion ◽  
The Magnetic Field

Free surface motion of a liquid metal submerged in an alternating magnetic field has been examined. A copper vessel filled with a liquid gallium is set in a coil for the imposition of the alternating magnetic field. The alternating magnetic field penetrates into a liquid gallium only from an upper free surface because thickness of the copper vessel is larger than the electromagnetic skin layer of copper. Time variation of displacement of the standing wave loop excited on the free surface is detected by a laser level sensor. The standing wave was suppressed not only by intensification of the magnetic field magnitude but also increase of the magnetic field frequency.

Magnetic Field Effect on the Natural Convection of a Liquid Metal in a Horizontal Cylinder

2013 ◽  
Author(s):  
Z. H. Wang ◽  
S. Yang ◽  
H. Chen
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Natural Convection ◽  
Liquid Metal ◽  
Horizontal Cylinder ◽  
Movement Direction ◽  
Liquid Gallium ◽  
Induced Current ◽  
Convection And Heat Transfer ◽  
The Magnetic Field

Magneto-hydrodynamic (MHD) effects are widely exploited in different industrial processes. MHD play an essential role in nuclear fusion, where it is involved in the behavior of the liquid metal alloys employed in some of the currently considered designs of tritium breeding blankets. Results of numerical simulations are presented for the natural convection of a liquid metal placed in a horizontal cylinder in the presence of a vertical magnetic field. When there is an additional magnetic field, an induced current is produced by the movement of the liquid metal in a magnetic field. Induced current and magnetic field interaction produced a Lorentz force which is opposite to the movement direction and inhibits the natural convection and heat transfer intensity. The numerical results show that the magnetic field has a observable effect at the heat transfer process of the liquid metal natural convection in a horizontal cylinder. An interesting effect of the magnetic field during the internal flow is the deceleration of the flow velocity for liquid Gallium. The magnetic field in the horizontal radial direction, which is perpendicular to the natural convection caused by the temperature gradient all the while, has the most significant influence on the natural convection, while the influence on the axial direction is comparatively weak in medium magnetic field. With the increase of the intensity of magnetic field, the inhibition is more obvious.

Observing the galactic magnetic field

1967 ◽  
Vol 31 ◽  
pp. 375-380
Author(s):  
H. C. van de Hulst
Keyword(s):  
Magnetic Field ◽  
Fair Agreement ◽  
Solar Neighbourhood ◽  
Galactic Magnetic Field ◽  
The Magnetic Field

Various methods of observing the galactic magnetic field are reviewed, and their results summarized. There is fair agreement about the direction of the magnetic field in the solar neighbourhood:l= 50° to 80°; the strength of the field in the disk is of the order of 10-5gauss.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

On the Configuration of the Magnetic Field of β CrB

1976 ◽  
Vol 32 ◽  
pp. 613-622
Author(s):  
I.A. Aslanov ◽  
Yu.S. Rustamov
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Radial Velocity ◽  
Magnetic Field Strength ◽  
Complex Shape ◽  
Rotation Period ◽  
Field Variation ◽  
Magnetic Field Variation ◽  
Secular Variations ◽  
The Magnetic Field

SummaryMeasurements of the radial velocities and magnetic field strength of β CrB were carried out. It is shown that there is a variability with the rotation period different for various elements. The curve of the magnetic field variation measured from lines of 5 different elements: FeI, CrI, CrII, TiII, ScII and CaI has a complex shape specific for each element. This may be due to the presence of magnetic spots on the stellar surface. A comparison with the radial velocity curves suggests the presence of a least 4 spots of Ti and Cr coinciding with magnetic spots. A change of the magnetic field with optical depth is shown. The curve of the Heffvariation with the rotation period is given. A possibility of secular variations of the magnetic field is shown.

Materials for Electron Beam Information Storage

1969 ◽  
Vol 27 ◽  
pp. 152-153 ◽  
Author(s):  
D. E. Speliotis
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Recent Literature ◽  
Electron Beams ◽  
Information Storage ◽  
The Subject ◽  
The Magnetic Field

The interaction of electron beams with a large variety of materials for information storage has been the subject of numerous proposals and studies in the recent literature. The materials range from photographic to thermoplastic and magnetic, and the interactions with the electron beam for writing and reading the information utilize the energy, or the current, or even the magnetic field associated with the electron beam.

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