scholarly journals Magnetic Field Usage for the Removal of Iron by Filtration-Assisted Different Filter Materials

Proceedings ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 6
Author(s):  
Ewa Szatylowicz ◽  
Iwona Skoczko

The conducted research concerned the effect of a magnetic field (MF) on the removal of iron compounds. The tested process was filtration through a quartz sand bed with a grain size of 0.4–0.8 mm. Another examined material was activated alumina. The obtained results proved that the MF had a significant impact on the efficiency of iron removal from a water filtrated trough than activated alumina. It was proven that the effect of the magnetic field on the filtration process using other filtration materials, was insignificant.

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1584 ◽  
Author(s):  
Ewa Szatyłowicz ◽  
Iwona Skoczko

Currently, methods of water purification and aqueous solutions leading to effective reduction of introduced chemical compounds into water purification systems have become the subject of research. Physical methods have become an alternative, because by subjecting water and aqueous solutions to UV (ultraviolet) radiation or magnetic fields (MF), either ultrasonic or electric, it is possible to influence the change of structure, which results in changes in the properties of water and aqueous solutions. This paper attempts to verify the influence of a weak magnetic field on the removal of iron and manganese compounds in the filtration process on gravel of 1–2 mm granulation, sand of 0.4–0.8 mm granulation, activated alumina and activated carbon. The conducted research proved that MF has a significant influence on the effectiveness of iron and manganese removal from water in the case of alumina, while in the filtration process through other filter materials the effect of MF was small.


2020 ◽  
Vol 634 ◽  
pp. L15 ◽  
Author(s):  
V. Guillet ◽  
J. M. Girart ◽  
A. J. Maury ◽  
F. O. Alves

Context. The azimuthal polarization patterns observed in some protoplanetary disks by the Atacama Large Millimetre Array (ALMA) at millimeter wavelengths have raised doubts about whether they are truly produced by dust grains that are aligned with the magnetic field lines. These conclusions were based on the calculations of dust polarized emission in the Rayleigh regime, that is, for grain sizes that are much smaller than the wavelength. However, the grain size in such disks is typically estimated to be in the range of 0.1−1 mm from independent observations. Aims. We study the dust polarization properties of aligned grains in emission in the Mie regime, that is, when the mean grain size approaches the wavelength. Methods. By using the T-MATRIX and DustEM codes, we computed the spectral dependence of the polarization fraction in emission for grains in perfect spinning alignment for various grain size distributions. We restricted our study to weakly-elongated oblate and prolate grains of astrosilicate composition that have a mean size ranging from 10 μm to 1 mm. Results. In the submillimeter and millimeter wavelength range, the polarization by B-field aligned grains becomes negative for grains larger than ∼250 μm, meaning that the polarization vector becomes parallel to the B-field. The transition from the positive to the negative polarization occurs at a wavelength of λ ∼ 1 mm. The regime of negative polarization does not exist for grains that are smaller than ∼100 μm. Conclusions. When using realistic grain size distributions for disks with grains up to the submillimeter sizes, the polarization direction of thermal emission by aligned grains is shown to be parallel to the direction of the magnetic field over a significant fraction of the wavelengths typically used to observe young protoplanetary disks. This property may explain the peculiar azimuthal orientation of the polarization vectors in some of the disks observed with ALMA and attest to the conserved ability of dust polarized emission to trace the magnetic field in disks.


2005 ◽  
Vol 492-493 ◽  
pp. 665-672 ◽  
Author(s):  
A. Ozieblo ◽  
Tomasz Wejrzanowski ◽  
K. Konopka ◽  
Mikolaj Szafran ◽  
Krzysztof Jan Kurzydlowski

This paper describes the technology and microstructure of Al2O3-Fe functionally graded composites, FGM, obtained by slip-casting under magnetic field. Alumina a-Al2O3, provided by Alcoa (symbol A16SG), with average grain size of 0.5 µm, and iron powder, (symbol Distaloy AB) from Hoganas, with average grain size of 35 µm, were used to produce a series of specimens which differed in contents of Fe particles in Al2O3. As a source of magnetic force a permanent magnet was used. Preforms were sintered in a vacuum at temp. 1470oC. The microstructures of the specimens were quantitatively described via stereological methods. Sections, parallel to the magnetic field lines were analyzed using special image analysis software. Stereological methods presented in this work have been used to determine gradient in the volume fraction of the Fe particles and variation in their size and dispersion. These parameters are essential for controlling the technological process of interest and to design microstructure for needed properties (fracture toughness).


2015 ◽  
Vol 1123 ◽  
pp. 260-263
Author(s):  
Christian Fredy Naa ◽  
Didier Fasquelle ◽  
Manuel Mascot ◽  
Suprijadi ◽  
Sparisoma Viridi ◽  
...  

The resistivity relaxation in magnetic material is one of the important characteristics for reliable device operations. It also provides insight to the physics of magnetic material. Furthermore, this characteristic is related to the micro structural of the material. In this paper, the resistivity relax- ation of different grain sizes of La0.7Sr0.3MnO3(LSMO) nanoparticles has been studied. The LSMO nanoparticles was synthesized by sol-gel method and to obtain different grain size, the samples were sintered at different temperatures ranging from 800◦C to 1100◦C. The resistivity relaxation measurements were recorded for 500-1500s under the influence of magnetic field in range 25-110mT in room temperature. Under the influence of magnetic field, the resistivity of all samples were slowly de- creases as a function of time following logarithmic behavior. Moreover, no saturation was observed in the measurement time span. The resistivity ratio ρ(t)/ρ(0) as a function of time t was fitted by using logarithmic model. It is shown that resistivity relaxation depends on the grain size and the strength of the magnetic field.


2014 ◽  
Vol 979 ◽  
pp. 297-301 ◽  
Author(s):  
Arpapong Changjan ◽  
Pongkaew Udomsamuthirun

Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature. Fe-based superconductors are superconductors whose containing iron compounds and having a very high critical magnetic field. London penetration depth can assist in the study of the behavior of the critical magnetic field. The London penetration depth is the distance to which a magnetic field penetrates into a superconductor and becomes equal to 0.367879 times that of the magnetic field at the surface of the superconductor. In this paper, the London penetration depth of Fe-based superconductors is studied by Ginzburg-Landau scenery. Free energy of Fe-based superconductors is assumed by modified the free energy of two-band magnetic superconductors model and theof Fe-based superconductors is derived analytically. Finally, the temperature dependence of is investigated and applied to Single-Crystal superconductors.


1967 ◽  
Vol 31 ◽  
pp. 375-380
Author(s):  
H. C. van de Hulst

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.


1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož

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.


2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath

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.


1976 ◽  
Vol 32 ◽  
pp. 613-622
Author(s):  
I.A. Aslanov ◽  
Yu.S. Rustamov

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.


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