scholarly journals An Analytical–Experimental Approach to Quantifying the Effects of Static Magnetic Fields for Cell Culture Applications

2020 ◽  
Vol 10 (2) ◽  
pp. 531
Author(s):  
Pablo Ferrada ◽  
Sebastián Rodríguez ◽  
Génesis Serrano ◽  
Carol Miranda-Ostojic ◽  
Alejandro Maureira ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Permanent Magnets ◽  
Bubbly Flow ◽  
Scenedesmus Obliquus ◽  
Relative Difference ◽  
Magnetic Flux Density ◽  
The South ◽  
Nannochloropsis Gaditana ◽  
Static Magnetic Fields ◽  
The North

This work aimed to study the effects of static magnetic fields (SMFs) on cell cultures. A glass flask was filled with a liquid medium, which was surrounded by permanent magnets. Air was introduced through a tube to inject bubbles. Two magnet configurations, north and south, were used as perturbation. Scenedesmus obliquus and Nannochloropsis gaditana, growing in Medium 1 and 2, were subjected to the bubbly flow and SMFs. Differences between media were mainly due to conductivity (0.09 S/m for Medium 1 and 4.3 S/m for Medium 2). Joule dissipation ( P ) increased with the magnetic flux density ( B 0 ), being 4 orders of magnitude higher in Medium 2 than in 1. Conversely, the time constant ( τ P ) depended on B 0 , being nearly constant for Medium 1 and decreasing at 449 s/T for Medium 2. Dissipation occurred with the same τ P (235 s) in Medium 1 and 2 at B 0 = 0.5 T. In Species 1, the SMF effect was inhibitory. For Species 2, a higher enzymatic activity was observed. For superoxide dismutase, the relative difference was 78% with the north and 115% with the south configuration compared to the control values. For the catalase, differences of 29% with the north and 23% with the south configuration compared to control condition were obtained.

scholarly journals Response to Static Magnetic Field-Induced Stress in Scenedesmus obliquus and Nannochloropsis gaditana

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 527
Author(s):  
Génesis Serrano ◽  
Carol Miranda-Ostojic ◽  
Pablo Ferrada ◽  
Cristian Wulff-Zotelle ◽  
Alejandro Maureira ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Enzymatic Activity ◽  
Scenedesmus Obliquus ◽  
Pulse Mode ◽  
Research Field ◽  
Continuous Exposure ◽  
Sod Activity ◽  
Nannochloropsis Gaditana ◽  
Static Magnetic Fields ◽  
Induced Stress

Magnetic fields in biological systems is a promising research field; however, their application for microalgae has not been fully exploited. This work aims to measure the enzymatic activity and non-enzymatic activity of two microalgae species in terms of superoxide dismutase (SOD), catalase (CAT), and carotenoids, respectively, in response to static magnetic fields-induced stress. Two magnet configurations (north and south) and two exposure modes (continuous and pulse) were applied. Two microalgae species were considered, the Scenedesmus obliquus and Nannochloropsis gaditana. The SOD activity increased by up to 60% in S. obliquus under continuous exposure. This trend was also found for CAT in the continuous mode. Conversely, under the pulse mode, its response was hampered as the SOD and CAT were reduced. For N. gaditana, SOD increased by up to 62% with the south configuration under continuous exposure. In terms of CAT, there was a higher activity of up to 19%. Under the pulsed exposure, SOD activity was up to 115%. The CAT in this microalga was increased by up to 29%. For N. gaditana, a significant increase of over 40% in violaxanthin production was obtained compared to the control, when the microalgae were exposed to SMF as a pulse. Depending on the exposure mode and species, this methodology can be used to produce oxidative stress and obtain an inhibitory or enhanced response in addition to the significant increase in the production of antioxidant pigments.

scholarly journals Modelling External Magnetic Fields of Magnetite Particles: From Micro- to Macro-Scale

Geosciences ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 133 ◽  
Author(s):  
Jiangang Ku ◽  
Miguel Valdez-Grijalva ◽  
Rongdong Deng ◽  
Weiran Zuo ◽  
Qidi Chen ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Relative Difference ◽  
Extraction Yield ◽  
Magnetic Flux Density ◽  
Magnetization Direction ◽  
Uniform Magnetization ◽  
Macro Scale ◽  
Sphere Radius ◽  
Magnetite Particles ◽  
Magnetic Extraction

We determine the role of particle shape in the type of magnetic extraction processes used in mining. We use a micromagnetic finite element method (FEM) to analyze the effect of external magnetic fields on the magnetic structures of sub-micron magnetite particles. In non-saturating fields, the magnetite particles contain multiple possible non-uniform magnetization states. The non-uniformity was found to gradually disappear with increasing applied field strength; at 100 mT the domain structure became near uniform; at 300 mT the magnetic structure saturates and the magnetization direction aligned with the field. In magnetic separation techniques, we suggest that 100 mT is the optimal field for magnetite to maximize the magnetic field with the lowest energy transfer; larger particles, i.e., >1 µm, will likely saturate in smaller fields than this. We also examined the effect of external magnetic fields on a much larger irregular particle (L × W × H = 179.5 × 113 × 103 μm) that was too large to be examined using micromagnetics. To do this we used COMSOL. The results show the relative difference between the magnitude of magnetic flux density of the particle and that of a corresponding sphere of the same volume is <5% when the distance to the particle geometry center is more than five times the sphere radius. The ideas developed in this paper have the potential to improve magnetic mineral extraction yield.

Transmittal properties of a superconductor-ferromagnetic metamaterial subjected to magnetic fields generated by the permanent magnets

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542049
Author(s):  
H. Liu ◽  
X. T. Li ◽  
P. B. Zhou ◽  
H. Zhang ◽  
C. Yang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Permanent Magnets ◽  
Transformation Optics ◽  
Optimal Structure ◽  
Magnetic Shielding ◽  
Static Magnetic Fields ◽  
Coaxial Cylinders ◽  
Geometrical Distribution ◽  
The Magnetic Field

Superconductor-ferromagnetic (FN) metamaterial with effective magnetic shielding and transmittal properties that allow the cloaking and transferring of static magnetic fields has been introduced. Most metamaterials consist of different arrangements of superconducting and ferromagnetic materials whose performance and feasibility mainly depend on the involved materials, their geometrical distribution and the permeability of each. In this paper, combining the method of transformation optics with the design of metamaterials, we experimentally demonstrated a superconductor-FM metamaterial system, composed of two coaxial cylinders of different lengths, to investigate the influence of the length and the properties of superconducting material on the magnetic transferring properties of the magnetic field produced by the permanent magnets. By comparing the transmittal magnetic field of different cases, the optimal structure has been ultimately achieved in terms of calculating the transmitted magnetic field ratios. The insights attained by the present study are aimed to provide useful implications for the design of wireless energy transmission and increasing the efficiency of magnetic transmittal devices.

scholarly journals Impact of Static Magnetic Field on the Antioxidant Defence System of Mice Fibroblasts

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Marek Glinka ◽  
Stanisław Gawron ◽  
Aleksander Sieroń ◽  
Katarzyna Pawłowska-Góral ◽  
Grzegorz Cieślar ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Magnetic Field ◽  
Magnetic Fields ◽  
Static Magnetic Field ◽  
Permanent Magnets ◽  
Energy State ◽  
Redox Homeostasis ◽  
Static Magnetic Fields ◽  
Antioxidant Defence System ◽  
The Impact

Results of research assessing the biological impact of static magnetic fields are controversial. So far, they have not provided a clear answer to their influence on cell functioning. Since the use of permanent magnets both in everyday life and in industry becomes more and more widespread, the investigations are continued in order to explain these controversies and to evaluate positive applications. The goal of current work was to assess the impact of static magnetic field of different intensities on redox homeostasis in cultures of fibroblasts. The use of permanent magnets allowed avoiding the thermal effects which are present in electromagnets. During the research we used 6 chambers, designed exclusively by us, with different values of field flux density (varying from 0.1 to 0.7 T). We have noted the decrease in the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx). The static magnetic fields did not modify the energy state of fibroblasts— adenosine triphosphate (ATP) concentration was stable, as well as the generation of malondialdehyde (MDA)—which is a marker of oxidative stress. Results of research suggest that static magnetic fields generated by permanent magnets do not cause oxidative stress in investigated fibroblasts and that they may show slight antioxidizing activity.

scholarly journals Observations of the Polar Magnetic Fields

1971 ◽  
Vol 43 ◽  
pp. 714-724 ◽  
Author(s):  
Jan Olof Stenflo
Keyword(s):  
Magnetic Fields ◽  
South Pole ◽  
The South ◽  
The North ◽  
General Field ◽  
Latitude Variation ◽  
Polar Magnetic Fields ◽  
Visual Measurements ◽  
Good Agreement ◽  
Made In

Results from observations of the polar magnetic fields made in 1968 with the Mount Wilson magnetograph are reported. The field was of south polarity near the heliographic north pole and of north polarity near the south pole. The inversion line of the field was at latitude +70° in the north hemisphere and −55° in the south, which coincides with the position of the polar prominence zones at that time. Observations made simultaneously at the Crimean Astrophysical Observatory are in good agreement with the Mt. Wilson data and confirm the latitude variation of the field.A few hundred of Hale's plates from 1914, which he had used to determine the Sun's general magnetic field, have been remeasured. The plates were automatically scanned with a digitized microphotometer, and the treatment of the data was made with a computer. While the visual measurements by Van Maanen had given a strong general field similar to that of a dipole, the computer reductions did not reveal any significant field (stronger than 5 G) at any latitude.

scholarly journals Study of the effect of nitrogen and hydrogen on the structure and magnetic properties of (Sm, Er)2Fe17 alloys

2021 ◽  
Vol 2103 (1) ◽  
pp. 012073
Author(s):  
I S Tereshina ◽  
S V Veselova ◽  
O V Akimova ◽  
M A Paukov ◽  
A Yu Karpenkov ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Permanent Magnets ◽  
Magnetic Hysteresis ◽  
Partial Substitution ◽  
Pulsed Magnetic Fields ◽  
Mechanical Grinding ◽  
Static Magnetic Fields ◽  
X Ray ◽  
Powder Samples ◽  
Grinding Time

Abstract Materials based on the Sm2Fe17 compound with nitrogen have great potential for the manufacture of highly efficient permanent magnets. The initial, nitrided, and hydrogenated alloys based on the Sm2Fe17 intermetallic compound with partial substitution of erbium atoms for samarium atoms Sm1.2Er0.8Fe17(H, N)x have been studied by X-ray phase analysis and scanning electron microscopy. Nanopowders of Sm1.2Er0.8Fe17N2 were obtained by mechanical grinding. The grinding time was varied from 0 to 60 minutes. The magnetic hysteresis properties of all powder samples were studied in static magnetic fields up to 7 T, as well as in pulsed magnetic fields up to 60 T. The strength of the intersublattice exchange interaction was estimated. The obtained values λ are valid only for the explored concentration of Sm/Er ions.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

US and Russian policies and strategies in the Middle East: Iraq and Syria as a model

2019 ◽  
pp. 220
Author(s):  
Esraa Aladdin Noori ◽  
Nasser Zain AlAbidine Ahmed
Keyword(s):  
Middle East ◽  
East Asia ◽  
Balance Of Power ◽  
Western World ◽  
International Conflicts ◽  
The South ◽  
The West ◽  
The North ◽  
East Region ◽  
Middle East Region

The Russian-American relations have undergone many stages of conflict and competition over cooperation that have left their mark on the international balance of power in the Middle East. The Iraqi and Syrian crises are a detailed development in the Middle East region. The Middle East region has allowed some regional and international conflicts to intensify, with the expansion of the geopolitical circle, which, if applied strategically to the Middle East region, covers the area between Afghanistan and East Asia, From the north to the Maghreb to the west and to the Sudan and the Greater Sahara to the south, its strategic importance will seem clear. It is the main lifeline of the Western world.

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