Effect Of Low Magnetic Field Research Articles

A low frequency magnetic field regulated the synthesis of carotenoids in Rhodotorula mucilaginosa by influencing iron metabolism

The purpose of this study is to investigate the effect of low frequency magnetic fields (LFMF) on carotenoid synthesis and iron metabolism in Rhodotorula mucilaginosa and to explore potential connections between the two processes. Various LFMF intensities were employed to assess carotenoid production, intracellular iron content, and the expression levels of genes related to carotenoid synthesis and iron metabolism in R. mucilaginosa. The results show that a LFMF could promote carotenoid synthesis, resulting in varying increases in intracellular iron content. Specifically, the expression of the iron metabolism-related gene transferrin receptor (TFR) was upregulated, while the expression of ferroportin 1 (FPN1) was downregulated. Meanwhile, the expressions of the carotenoid synthesis-related genes geranylgeranyl diphosphate synthases (GGPPS) and phytoene synthase (PSY) displayed varying degrees of upregulation at different time points. Further, the TFR and FPN1 gene knockout strains of R. mucilaginosa were subjected to treatment with a 3.5-mT LFMF, the results of which showed that an LFMF is capable of influencing the iron metabolism levels and subsequently regulating carotenoid synthesis in R. mucilaginosa.

On the Electrodeposition of Zinc in Low Magnetic Fields

Abstract While aqueous zinc-based batteries have garnered much research on account of their improved safety, lower cost, and easier fabrication over lithium-ion batteries, they remain held back by dendrite growth on the anode. While many different solutions have been proposed, these solutions often greatly complicate the synthesis or materials in the battery. The application of a magnetic field across the battery has been shown to inhibit dendrite formation without the need for any materials or interface engineering. Herein, we provide a study on the effects of low magnetic fields on the electrodeposition and cycling of zinc in various aqueous systems. We demonstrate that although stronger fields have more immediate impacts on the morphology of zinc deposits, low magnetic fields are still suitable for inhibiting dendrite growth over long periods of cycling. Magnetic field strengths as low as 29 mT were shown to decrease charge transfer resistance of zinc ion deposition by up to 54% and to stabilize the cycling of Zn/Zn symmetric cells. Furthermore, the versatility of magnetic field application was demonstrated by affecting the morphology of zinc deposits on both copper and single-walled carbon nanotubes, which are both compatible with anode-free configurations of aqueous zinc-ion batteries.

Comparative study of low magnetic field effects in finger-finger and finger-split gate single electron pumps

Single Electron Pump (SEP) devices that can deliver single electrons at high frequencies are fabricated using two different gate geometries. The pump quantum dot (QD) can be defined either using two finger gates where the pump operates in what is known as the conventional pumping regime (CPR), or alternatively, the QD can be designed with the use of a single finger gate and split gate, where the pump operates in the long pumping regime (LPR). Here we investigate pump-maps produced in both the CPR and LPR under the effects of a low magnetic field (1 T to −1 T) and observe both the evolution of the pump-map and pump accuracy. Measurements were carried out in a cryogen free dilution refrigeration system with the use of a superconducting magnetic. Clear discrepancies between the behaviour of current in the different regimes can be seen indicating a fundamental difference in the operation of the pumps in the two different pumping regimes.

Effect of low magnetic field during nickel electroplating on morphology, structure, and hardness

Nickel (Ni) layers are commonly utilized in various applications, such as automotive components. By using a magnetic field during the electroplating process, it is possible to achieve better properties. Ni electroplating was conducted in 0.5 M nickel sulphate in this research. Various low intensities of the magnetic field (0.08 T and 0.14 T) were applied during the electroplating process. In the past, it has been demonstrated that an increase in low magnetic field could result in a decrease in crystallite size and a rise in hardness. Samples were weighed with a digital scale to determine the deposition rate and current efficiencies. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and hardness tester were performed to investigate Ni layers properties. The magnetic field influences the deposition rate, cathodic current efficiency, surface morphology, structure, and hardness properties. The increase in the magnetic field caused a wider grain and smaller crystallite sizes. The crystallite sizes of the NiS - 0, NiS - 8, and NiS - 14 samples are 33.536 nm, 33.083 nm, and 28.540 nm, respectively. The hardness of the NiS - 0, NiS - 8, and NiS - 14 samples are 212.33 HV, 255.01 HV, and 267.214 HV, respectively. Higher hardness could be reached by reducing the size of crystallites. The influence of the magnetic field could enhance hardness during the electroplating process.

Effect of low magnetic field heat treatment process on grain sizes and soft magnetic properties of Finemet cores

In this study, we investigate the effect of low transverse magnetic field annealing on the soft magnetic properties of cores made of industrial Finemet ribbons. The variation of static/dynamic magnetic properties and average grain size of the cores obtained by zero-field annealing (ZFA), secondary-field annealing (SMA) and direct-field annealing (DMA) are studied in detail. It is found that the average grain size obtained by DMA decreased compared to that of the ZFA sample, while the average grain size increased slightly after SMA. The effective permeability (μe) of the ZFA sample after SMA decrease less than that of the ZFA sample with increasing frequency. The μe of the DMA sample decreases significantly at the low-frequency stage but tends to decrease smoothly overall, maintaining high effectiveness at high frequencies magnetic permeability. For example, at 100 kHz, the μe of ZFA at 550 °C temperature is only 0.6 × 104, while the μe of SMA and DMA are 2.0 × 104 and 2.2 × 104, respectively. Meanwhile, the Hc = 1.85 A/m, Br = 0.59 T after ZFA and Hc = 1.67 A/m after DMA show no significant decrease compared to ZFA. While Hc = 0.55 A/m, Br = 0.08 T after SMA. Due to the field anisotropy constant Ku generated after SMA and DMA, the average anisotropy constant is dominated by Ku, the domain structure becomes simple and uniform, and the domain width becomes larger. This leads to a decrease in core losses with increasing frequency and improves the high-frequency characteristics of the core. These results can provide good guidance for performance optimization for Finemet alloys in a wide frequency range.

Various Low Magnetic Field Effect on Electrochemical Performance of Asymmetric Supercapacitor MnO<sub>2</sub>- Carbon-Based Composites

Application of energy storage systems such as supercapacitors can not be separated from the magnetic fields effect. In the last decade, it’s rare to find research reports about various low magnetic field effects on supercapacitor performance. Asymmetric supercapacitors based on MnO2-Carbon were made to analyze its electrochemical performance changes by magnetic field in 0-50 mT. Magnetic field was applied in flow direction from cathode (MnO2-C) to anode (C) during electrochemical performance test using Galvanostatic Charge-Discharge (C-D) instrument. The electrochemical performance was increasing in charging (91%) and discharging (22%) time of asymmetric supercapacitors. Impressively, the 50 mT magnetic field showed a high specific capacitance of 61.9 F/g at 0.1 A/g. The supercapacitor system delivers specific energy (17.8 Wh/kg), specific power density (329.72 W/kg), and outstanding stability (79% in 50 cycles). The electrochemical improvement by magnetic field indicates a highly promising application of this method in future supercapacitor devices.

Effect of Low Magnetic Field on Biomimetic Deposition of Hydroxyapatite on Titanium and BIOLINE Stainless Steel

In this work, we evaluated the effect of a low magnetic field on the deposition of hydroxyapatite (HAp) on different metallic substrates. The substrates studied were titanium and BIOLINE stainless steel SS316LVM with and without Ta and TaN/Ta coatings. Before deposition, the uncoated Ti and SS316LVM substrates were treated with alkali to improve the adhesion of the films prompted to be formed. Next, all substrates (coated and uncoated) were immersed in stimulated body fluid (SBF) at physiological conditions of 37 °C, pH = 7.4, in the presence of magnetic fields from 0.15 T and 0.22 T for 7, 10, and 14 days. The formed films were characterized using SEM, FTIR, and the contact angle. Ti and SS316LVM substrates presented Ca/P relations closer to the stoichiometric HAp. It was demonstrated that in both coatings, Ta and Ta/N, an increase of the bioactivity was obtained. Additionally, our results showed that the application of magnetic fields has a significant effect on the increment in the mass:area ratio of HAp. Finally, the contact angle values were lower than 90°, showing an increase in hydrophilicity with respect to the metallic substrates.

Resistive Switching in HfO2-x/La0.67Sr0.33MnO3 Heterostructures: An Intriguing Case of Low H-Field Susceptibility of an E-Field Controlled Active Interface.

High-performance nonvolatile resistive random access memories (ReRAMs) and their small stimuli control are of immense interest for high-speed computation and big-data processing in the emerging Internet of Things (IoT) arena. Here, we examine the resistive switching (RS) behavior in growth-controlled HfO2/La0.67Sr0.33MnO3 (LSMO) heterostructures and their tunability in a low magnetic field. It is demonstrated that oxygen-deficient HfO2 films show bipolar switching with a high on/off ratio, stable retention, as well as good endurance owing to the orthorhombic-rich phase constitution and charge (de)trapping-enabled Schottky-type conduction. Most importantly, we have demonstrated that RS can be tuned by a very low externally applied magnetic field (∼0-30 mT). Remarkably, application of a magnetic field of 30 mT causes RS to be fully quenched and frozen in the high resistive state (HRS) even after the removal of the magnetic field. However, the quenched state could be resurrected by applying a higher bias voltage than the one for initial switching. This is argued to be a consequence of the electronically and ionically "active" nature of the HfO2-x/LSMO interface on both sides and its susceptibility to the electric and low magnetic field effects. This result could pave the way for new designs of interface-engineered high-performance oxitronic ReRAM devices.

Effects of Magnetic Fields in Hot White Dwarfs

Abstract In this work, we study the effects of magnetic fields on hot white dwarfs. We model their interior as a nuclei lattice surrounded by a relativistic free Fermi gas of electrons, accounting for effects from temperature, Landau levels, and anomalous magnetic moment. We find that, at low densities (corresponding to the outer regions of star), both temperature and magnetic field effects play an important role in the calculation of microscopic thermodynamical quantities. To study macroscopic stellar structures within a general-relativistic approach, we numerically solve the coupled Einstein–Maxwell equations for fixed entropy per particle configurations and discuss how temperature affects stellar magnetic field profiles, masses, and radii.

Low magnetic field effects on a photoinduced electron transfer reaction in an ionic liquid

Low Magnetic field effects on a photoinduced electron transfer reaction between benzophenone and 1,4-diazabicyclo [2.2.2] octane (DABCO) in an ionic liquid of N,N,N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)amide were studied with nanosecond transient absorption measurements. At a magnetic field (~2mT) comparable with the hyperfine coupling in DABCO cation, so-called low field effects (LFEs), whose effect is opposite to the magnetic field effects caused by the hyperfine coupling mechanism, were observed on the yield of the benzophenone anion radical. The magnitude of the LFE is linearly increased with the increase of the lifetime of the radical ion pair. The present study provides basic data to clarify the mechanism of LFEs in biological systems.

Effect of low frequency magnetic field (LFMF) on seed quality of radish (Raphanus sativus L.) seeds

In recent years, the application of magnetism in agriculture has been paid more and more attention to, especially in the field of its treatment on the seed germination and physiological indexes of seedlings grown out of them. In this experiment, the radish (Raphanus sativus L.) seeds of two cultivars ‘Carmen’ and ‘Szkarłatna z Białym Końcem’ were treated by 20 mT low frequency magnetic field (LFMF) for 10, 30 and 60 minutes, respectively. The MF was generated from a Viofor JPS Delux - a patented device adopted from the routine medical magnetic therapy. By measuring their seed germination rate (energy), seedling length and fresh weight, it was proved that LFMF improved the seed quality of both radish cultivars and the best results were received for the longest exposing time. The received that way results were similar as reported for priming of radish seeds. The developed treatment has a great potential in replacing traditional seed priming methods. However, for its commercial use, for selected crops and cultivars, further research is still needed.

Low frequency magnetic field plus high pH promote the quality of pork myofibrillar protein gel: A novel study combined with low field NMR and Raman spectroscopy

This study investigated the combined effects of low frequency magnetic field (LF-MF) (3.8 mT) and pH (5–7) on pork myofibrillar protein (MP) gel quality. With LF-MF applying, the water ratio and migration rate both changed to varying extents. LF-MF modified secondary structure of MP by exposing tryptophan and tyrosine residues to participate in hydrogen bonding with water, as well changing α-helix and β-sheet to varying extents; LF-MF also drove molecular rearrangement and crosslinking. LF-MF brought gel larger and more ordered network to trap more water. And the water holding capacity of gels significantly increased by 2.50% and 2.47% when LF-MF involved at appropriate pH (pH 6.5 and 7.0). Collectively, our results support an optimum treatment (pH 6.5 or 7.0 with applying LF-MF) for the improvement in gel quality of pork MP, and the combination of physical and chemical treatments casts a new light into improving product quality during meat processing.

Effect of low intensity static magnetic field on purified water in stationary condition: Ultraviolet absorbance and contact angle experimental studies

This work focused its attention on the effect of a low intensity static magnetic field on purified water: more specifically, on how the ultraviolet absorbance and the surface tension of the water may be affected. It has been found that pure water, exposed to a magnetic field for periods of time, does not absorb the ultraviolet radiation in an asymptotic way but shows a local maximum at 15 min. It is also shown that the contact angle of droplets on paraffin can be reduced by up to 5° by exposing the water to a 10 mT static magnetic field.

Low frequency magnetic fields modification on hydrogen peroxide oxidized myoglobin-isolate and mechanisms underlying the chain reaction process

The effects of low frequency magnetic field (0–12 mT) on hydrogen peroxide oxidized myoglobin-isolate (MbI) were investigated. The results indicate that the primary target of the hydrogen peroxide oxidation was Met(FeIII)Mb, leading to the fall off of iron ions from the porphyrin ring. Additionally, the increased magnetic field (≥9 mT) enhanced the release of more iron ions to react with H2O2, giving rise to the production of more hydroxyl radicals and the shift of oxidation site from porphyrin ring to Mb skeleton. Moreover, the directional movement of iron ions induced by magnetic field caused the generation of local micro-electric field and the rearrangement of charged groups on the protein surface or near-surface, thus affecting Mb aggregation. Overall, the magnetic field interfered with the hydrogen peroxide chain reaction process, changed the redox equivalents of Mb, and shifted the oxidation sites of Mb.

Low magnetic field effects on triplet pair annihilations at canonical orientations

Using the density operator formalism, a simple analytical model is developed to study low magnetic field effects on triplet pair annihilations in organic solids. Analysis is restricted to canonical orientations where two identical triplet molecules have the same orientation and the direction of the external magnetic field is parallel to one of the principle axes of the dipolar coupling tensor for a triplet. The analytical solution reveals that the low magnetic field effect in the triplet pair arises from the anisotropic dipole-dipole coupling in a triplet. In the presence of the dipole-dipole coupling, the spin quantization axis for each triplet gradually changes with the increase of the external magnetic field from zero field to high field. The low magnetic field effect reaches a maximum when the Zeeman splitting between the spin states matches a dipole-dipole coupling component orthogonal to the external magnetic field direction. The result is also discussed with the low magnetic field effect in the radical pair with one isotropic hyperfine coupling.

Effect of low frequency magnetic field on efficiency of chromosome break repair

ABSTRACTDNA repair is essential to maintain genome integrity. There is scientific evidence that exposure to magnetic fields (MF) can produce alterations in DNA repair without clear conclusions. This work aims to study the cellular response to and repair of a very deleterious type of DNA damage, the DNA double strand break (DSB), in S. cerevisiae, under MF exposure. In S. cerevisiae cells, pairs of DSB were induced enzymatically by HO endonuclease by plating the cells on Galactose-containing media. The repair processes took place under exposure to a 50Hz, 2.45mT sinusoidal MF during 21 days. MF was generated by a pair of Helmholtz coils. MF induced 1.29- and 1.5-fold increase in the number of colonies grown at day 21 of exposure in relation to untreated controls for Pho91 and Rmd5 strain, respectively. In relation to the kinetics of DSB repair during MF exposure, a higher increase (55.56-fold) in DNA reparation was observed at day 15 for Rmd5 strain in relation to the slight increment (1.18-fold) found for Pho91 strain. The results suggest that long-term MF exposure could increase the DNA repair activity and there may be a relationship between the position of the DSB and the distance to the centromere.

Effects of low frequency magnetic field on myoglobin oxidation stability

The effects of low frequency magnetic field on myoglobin (Mb) oxidation stability were evaluated by treatments at 0, 3, 6, 9, 12 mT and storage for 10 h. The results showed that Mb oxidation was inhibited under all magnetic field treatments, due to the increase of total sulfhydryl and free amino groups (9 or 12 mT) from unfolding of Mb clusters (3, 9, 12 mT) as well as β-turn and β-sheet structures (9 or 12 mT). The unfolding also induced (i) the destruction or burial of iron porphyrin and tyrosine residues; (ii) the exposure of tryptophan; (iii) more uniform Mb particle size distribution (3, 9, 12 mT) and increased zeta potential (3, 6, 12 mT). Overall, magnetic field promoted exposed active groups as the preferred oxidation target, thus decreasing the oxidation rate of central iron atoms. It also promoted Mb stability by redistributing particle size and increasing zeta potential.

Effect of sinusoidal and pulsed magnetic field exposure on the chronological aging and cellular stability of S. cerevisiae

Purpose: The aim of this study is to investigate the effects of low frequency and intensity sinusoidal magnetic field (SMF) and pulsed magnetic field (PMF) exposure on the chronological aging and cellular stability of Saccharomyces cerevisiae.Materials and methods: The S. cerevisiae wild type strain (WS8105-1C) was exposed to SMF (2.45 mT, 50 Hz, continuous) and PMF (1.5 mT, 25 Hz, 8 h/day). Chronological aging was evaluated during 40 days. Survival was assayed by clonogenic assay and drop test. Cellular stability was studied by spontaneous mutation count and the index of respiratory competence (IRC).Results: We found that exposure to PMF produces an acceleration of cellular chronological aging, not observed in the groups treated with SMF. A decrease in the spontaneous frequency of mitochondrial mutation during aging was observed in PMF-treated samples. However, no alterations in the IRC during aging were found for both, SMF and PMF, treatments.Conclusions: Exposure to PMF produces the acceleration of aging and an alteration in cellular stability.

Effect of low magnetic field on single-diode dosimetry for clinical use

PurposeTo evaluate the effect of a low magnetic field (B-field, 0.35 T) on QED™ for clinical use. MethodsBlack and Blue QED were irradiated using tri-Co-60 magnetic resonance image-guided radiation therapy systems with and without the B-field. For both detectors, angular dependence of the beam orientation was evaluated by rotating the gantry and detector in parallel and perpendicular directions to the B-field. Angular dependence betweenthe directions of both QED and B-field was also measured. Response on the depth and output factor of both detectors was investigated for parallel and perpendicular setups, respectively. ResultsWhen Black QED was placed on a surface, detector response decreased by 1.8% and 4.5% for parallel and perpendicular setups, respectively, owing to the B-field. The angular dependence of the beam orientation was not affected by B-field for both detectors. There was a significant angular dependence between Black QED and B-field direction and for the Black QED when the gantry was rotated. Owing to the B-field, the detector response at 90° decreased by 2.4%, response of Black QED on the depth was changed only on the surface, and output factor of Black QED was changed only on the surface. The response of Blue QED was not affected by the B-field for all examined situations. ConclusionsUsing Black QED on a surface in the same position as that in the calibration requires some correction to the B-field. Blue QED does not require correction as it is not affected by the B-field.

Activation of the intracellular temperature and ROS sensor membrane protein STIM1 as a mechanism underpinning biological effects of low-level low frequency magnetic fields

The biological effects of low frequency magnetic fields (LF MF) at high flux densities are well known and the underlying mechanism is established. In contrast, health associated effects at lower flux densities, which can be found in the human environment, are controversial, and no accepted interaction mechanism has been presented.Here we present a hypothesis regarding the biological aspect of interaction between LF MF and cells. We suggest that the endoplasmic reticulum (ER) membrane protein STIM1, which functions as a sensor for several cellular conditions (low Ca2+ levels, temperature increase, increased levels of oxygen radicals, hypoxia), is a candidate LF MF sensor. Such a sensor function can be either direct (via local temperature increase caused by intracellularly induced electric fields), or indirect due to responses to increased reactive oxygen species (ROS) levels. Activated STIM1 leads to downstream effects by activation of signal transduction processes and changes in gene expression leading to secondary events. The nature of these changes would be dependent on both cell type and the particular physiological state the cell displays at the time of STIM1 activation.Results from testing of this hypothesis, as suggested in this paper, would greatly assist in understanding of the possible health-related effects of low-level LF MF. This would benefit both safety assessments regarding MF exposure as well as possible use of MF in medicine.A better understanding of the biological mechanisms underpinning MF exposure effects of living matter allows the targeted use of the fields in medical applications. There are several examples already in use based on empiric and not on mechanistic knowledge. Knowledge generated from our hypothesis testing makes it possible for MF based medical applications to be optimized.