Magnetic Lines Research Articles

Enhancement of functional properties of V0.6Ti0.4 alloy superconductor by the addition of yttrium

We show here that yttrium is immiscible and precipitates with various sizes in the body centered cubic V0.6Ti0.4 alloy superconductor. The number and size of the precipitates are found to depend on the amount of yttrium added. Precipitates with various sizes up to 30 μm are found in the V0.6Ti0.4 alloy containing 5 at. % yttrium. The large amount of line disorders generated by the addition of yttrium in this alloy is found to be effective in pinning the magnetic flux lines. While the superconducting transition temperature increases with the increasing amount of yttrium in the V0.6Ti0.4 alloy, the critical current density is maximum for the alloy containing 2 at. % yttrium, where it is more than 7.5 times the parent alloy in fields higher than 1 T. We found that the effectiveness of each type of defect in pinning the flux lines is dependent on the temperature and the applied magnetic filed.

Magnetic quivers and line defects — On a duality between 3d mathcal{N} = 4 unitary and orthosymplectic quivers

Supersymmetric Sp(k) quantum chromodynamics with 8 supercharges in space-time dimensions 3 to 6 can be realised by two different Type II brane configurations in the presence of orientifolds. Consequently, two types of magnetic quivers describe the Higgs branch of the Sp(k) SQCD theory. This is a salient example of a general phenomenon: a given hyper-Kähler Higgs branch may admit several magnetic quiver constructions. It is then natural to wonder if these different magnetic quivers, which are described by 3d mathcal{N} = 4 theories, are dual theories. In this work, the unitary and orthosymplectic magnetic quiver theories are subjected to a variety of tests, providing evidence that they are IR dual to each other. For this, sphere partition function and supersymmetric indices are compared. Also, we study half BPS line defects and find interesting regularities from the viewpoints of exact results, brane configurations, and 1-form symmetry.

Correlated Spatio-temporal Evolution of Extreme-Ultraviolet Ribbons and Hard X-Rays in a Solar Flare

Abstract We analyze the structure and evolution of ribbons from the M7.3 SOL2014-04-18T13 flare using ultraviolet images from the Interface Region Imaging Spectrograph and the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA), magnetic data from the SDO/Helioseismic and Magnetic Imager, hard X-ray (HXR) images from the Reuven Ramaty High Energy Solar Spectroscopic Imager, and light curves from the Fermi/Gamma-ray Burst Monitor, in order to infer properties of coronal magnetic reconnection. As the event progresses, two flare ribbons spread away from the magnetic polarity inversion line. The width of the newly brightened front along the extension of the ribbon is highly intermittent in both space and time, presumably reflecting nonuniformities in the structure and/or dynamics of the flare current sheet. Furthermore, the ribbon width grows most rapidly in regions exhibiting concentrated nonthermal HXR emission, with sharp increases slightly preceding the HXR bursts. The light curve of the ultraviolet emission matches the HXR light curve at photon energies above 25 keV. In other regions the ribbon-width evolution and light curves do not temporally correlate with the HXR emission. This indicates that the production of nonthermal electrons is highly nonuniform within the flare current sheet. Our results suggest a strong connection between the production of nonthermal electrons and the locally enhanced perpendicular extent of flare ribbon fronts, which in turn reflects the inhomogeneous structure and/or reconnection dynamics of the current sheet. Despite this variability, the ribbon fronts remain nearly continuous, quasi-one-dimensional features. Thus, although the reconnecting coronal current sheets are highly structured, they remain quasi-two-dimensional and the magnetic energy release occurs systematically, rather than stochastically, through the volume of the reconnecting magnetic flux.

Tailoring magnetic properties through variation of cations distribution in Zn-Cu ferrite nanoparticles prepared by exploding wire technique

In this paper, Zinc-Copper ferrite nanoparticles, synthesized via a novel exploding wire technique. The Fe3+ cation distribution of tetrahedral and octahedral sites of prepared nanoparticles is estimated through intensity analysis of powder X-ray diffraction. The preference of Zn2+ and Cu2+ towards tetrahedral and octahedral sub-lattices and their influence on hyperfine magnetic lines are determined through Mössbauer spectroscopy. The cation distributions of Fe3+ at tetrahedral and octahedral sites of Fe2O3 powder used as precursor for the synthesis of samples are estimated through sextet’s areas. The existence of Fe3+ oxidation state Zn-rich Zn0.7Cu0.3Fe2O4 and Cu-rich Zn0.3Cu0.7Fe2O4 nanoparticles is ascertained through Mössbauer and electron spin resonance analysis. The ferroelectric properties are studied through polarization versus electric field analysis. Zero field cooling-field cooling investigation substantiated superparamagnetic behavior and demonstrated the variation of saturation magnetization with respect to Zinc/Copper concentration, as per Neel’s and Yafet-Kittel models.

B-dot probe measurements on plasma plume expansion across the magnetic field

Time-varying diamagnetism in laser-produced plasma moving across a transverse magnetic field for different field strengths has been studied using fast imaging and magnetic probe. The emphasis of the present work is on the development of suitable B-dot probe, quantitative analysis of induced diamagnetic field in an expanding plasma plume and its effect on the applied magnetic field profiles. A Helmholtz coil with pulsed power system is used to produce uniform magnetic field varying from 0.13 T to 0.57 T. Helmholtz coil allows the plume imaging along the magnetic field lines, which gives the direct structural information of the induced diamagnetic cavity. A high frequency three-axis B-dot probe has been developed to measure the transient magnetic field. Different experimental approaches have been used to test the response, sensitivity and calibration of the developed probe. It has been observed that induced magnetic field displaced the external magnetic field that is plasma plume shows the diamagnetic behaviour for considered magnetic field range. The probe signals in directions orthogonal to the applied/induced magnetic lines are correlated with the distortion in applied magnetic field in three dimensional space, which is consistent with recently simulated topology of external magnetic field in similar experimental conditions [Patel et al, 2021 Plasma Phys. Control. Fusion 63 115020 ].

Numerical study of simultaneous transport of heat and mass transfer in Maxwell hybrid nanofluid in the presence of Soret and Dufour effects

The article aims to investigate the influence of copper (Cu) and a combination of copper (Cu) and aluminum oxide (Al2O3) on the simultaneous transfer of heat and mass in sodium alginate liquid moving over a circular pipe. This transport activity is modeled by the use of conservation laws with correlations for physical quantities of Cu, Al2 O3, and sodium alginate. Through cylindrical coordinates formulation, the set of partial differential equations is obtained. These models are solved numerically by the finite element method (FEM). The relaxation time associated with momentum diffusion in Maxwell fluid plays role in controlling the viscous region. Moreover, momentum relaxation time in Cu/sodium alginate is strong than that in Cu–Al2O3/sodium alginate. It is noticed from simulations that particles of Cu/ sodium alginate have a greater velocity than the velocity of Cu–Al2O3/sodium alginate. Therefore, distortion of magnetic lines by the flow of Cu/sodium alginate is more than the distortion of magnetic lines by the flow of Cu–Al2O3/sodium alginate. The rise in the thermal conductivity of sodium alginate due to simultaneous dispersion of Cu and Al2O3 is more than the rise in thermal conductivity of sodium alginate. Thus for maximum HT, the simultaneous dispersion of Cu and Al2O3 in sodium alginate is recommended.

Magnetic Peristaltic Ciliary Flow Regulates an Embryo Growth in the Human Fallopian Tube

The flow transport behavior in a peristaltic-ciliary fallopian tube in the human system caused by a sinusoidal pressure gradient due to magnetic lines of force has been investigated. A descriptive prototype model is established and presented in cylindrical coordinates for the fallopian tapered tubal linearly viscous fluid influenced by an external magnetic force in the human body. Under the wavelength approximation, the consequential partial differential equations governing this biological phenomenon are solved analytically. The solutions obtained are presented in modified Bessel functions of zeroth order of the first kind. Also, solutions are obtained for the velocity components along the axial and the radial directions, pressure gradient, pressure differences over a wavelength, and the stream function. The impacts of the various physical quantities of interest on the momentum transport, wavy curve patterns depicting the velocity range, and the pressure change are plotted. A comparison study of peristaltic, peristaltic-ciliary, and magnetic peristaltic-ciliary flows is also presented as a special case. Furthermore, the embryo's development in the interior of the narrow fallopian tube intramural fluid coming from the ampulla is discussed.

MHD Flow around Circular Cylinder UnderControl through three Different magnetic Permeability Status

Through the current work, the flow around an insulating cylinder of various magnetic permeability, submitted to a flow of an incompressible electrically conducting fluid has been investigated. The homogeneous fluid flow and the homogeneous applied magnetic field are aligned at infinity. When the cylinder has the similar magnetic permeability as the fluid, the applied field is not influenced by the cylinder. However, when the cylinder has a different magnetic permeability than that of the fluid, the applied field is agitated by the cylinder and then the flow structures will become different from those of the previous case. Consequently, two cases can be distinguished following the last state whereas the cylinder magnetic permeability may have less or greater value than the fluid one’s. The best agreed results that have been obtained following the comparison to the literature magnetic field behaviors were selected .The event has been occurred, where the convergence and divergence of the magnetic stream lines were realized to the previous both cases of magnetic permeability situations, respectively. In fact, an important influence of magnetic field on the fluid has been occurred. Consequently, it can be concluded that the fluid has significant influences on the cylinder structure, through the impact of the fluid structure phenomenon, the shedding vortex process and its suppression. Accordingly, good results of drag aerodynamic coefficient evolution were obtained at the fixed value of the Reynolds number Re=550, for different Stuart numbers, greater than and lessen than a critical value adopting at N=0.8.

Magnetic lump motion in saturated ferromagnetic films.

In this paper, we study in detail the nonlinear propagation of a magnetic soliton in a ferromagnetic film. The sample is magnetized to saturation by an external field perpendicular to film plane. A generalized (2+1)-dimensional short-wave asymptotic model is derived. The bilinearlike forms of this equation are constructed and exact magnetic line soliton solutions are exhibited. It is observed that a series of stable lumps can be generated by an unstable magnetic soliton under Gaussian disturbance. Such magnetic lumps are highly stable and can maintain their shapes and velocities during evolution or collision. The interaction between lump and magnetic solitons, as well as the interaction between two lumps, are numerically investigated. We further discuss the nonlinear motion of lumps in ferrites with Gilbert damping and inhomogeneous exchange effects. The results show that the Gilbert-damping effects make the amplitude and velocity of the magnetic lump decay exponentially during propagation. And the shock waves are generated from a lump when quenching the strength of inhomogeneous exchange.

Theoretical and experimental analysis of pulse compression capability in non-linear magnetic transmission line

This paper presents a theoretical and experimental analysis of nonlinear magnetic transmission lines and demonstrates the phenomenon and capability of a simultaneous rise and fall time compression. A theoretical approach is formulated in which a new version of the modified Korteweg–de Vries equation is developed utilizing the Gardner–Morikawa transformation, continuum limit approximation, Toda-lattice approximation, and Mei theory of Maxwellian circuits. The proposed theoretical foundation work is validated through experimental demonstration. The pulse generation in a nonlinear magnetic transmission line is then studied in detail, and the output pulse characteristics are explored under different magnetic field strengths and arbitrary magnetization directions. In particular, output waveforms are analyzed in terms of pulse amplitude, full width half maximum, detailed ringing level, and figure of merit. Magnetic losses that arise in the ferrite material are modeled. It is shown that these losses are responsible for originating dissipative effects, which in turn deteriorate pulse shaping and increase ringing level. The localized disturbance within ferrimagnetic materials is also studied, and its impact on the output waveforms is also discussed. This study can potentially open up a new and fruitful entry to explore magnetic materials and their impacts in the field of ultrafast electronics in parallel with nonlinear electrical transmission lines.

Numerical simulation of electron extraction from micro electron cyclotron resonance neutralizer under different magnetic circuits

The electron cyclotron resonance (ECR) neutralizer is an important part of the micro ECR ion thruster. The electrons extracted from the neutralizer are used to neutralize the ions extracted from the ECR ion source, thereby avoiding the surface charges accumulating on the spacecraft, and the behaviour of electron extraction affects the overall performance of the thruster. In order to investigate the electron extraction through the orifices of the micro ECR neutralizer, a two-dimensional particle-in-cell with Monte Carlo collision (PIC/MCC) model is established in this work. The effects of different magnetic circuits on the electron extraction of the neutralizer and the influence of different cavity lengths on the wall current loss are studied through numerical simulation. The effects of different magnetic circuit structures on the electron extraction and wall current loss of the neutralizer are studied. The calculation results show that the position of the ECR layer and the magnetic flux lines near the extraction orifices are very important for the electron extraction performance of the neutralizer. When the ECR layer is located upstream of the antenna, electrons are easily lost in migration and diffusion motion, and the energy required for the electrons to cross the potential well before the extraction hole is higher. If more magnetic flux lines pass parallelly through the extraction orifices, the neutralizer requires a small voltage to extract the same electron current. When the ECR layer is cut by the antenna or is located downstream of antenna, more electrons may migrate along the magnetic flux lines to the vicinity of the extraction orifices, thereby reducing the voltage of collector plate. The effects of different cavity lengths on the extraction of electrons under the same magnetic circuit structure are studied. It is found that increasing the length of the cavity allows more parallel-axis magnetic flux lines to pass through the extraction holes to avoid electron loss on the surface of the extraction plate, and thus increasing the extraction electron current. The research results conduce to designing a reasonable neutralizer magnetic circuit and cavity size.

Magnetic field assisted 3D printing of short carbon fibre-reinforced polymer composites

This paper investigates and discusses the outcomes from an ongoing feasibility research being conducted at Advanced Composites Research Focused Group on 3D printing polymers and carbon composites subjected to localised magnetic field force lines. Magnetic equipped composite processes are starting to become an important new development for structural applications. Specific to this paper, in-situ alignment of short carbon fibres (∼1 mm length) in thermoplastic polymer filaments (Onyx FR, a Nylon base with micro carbon-fibres with a flame retardant additive supplied by Markforged) during a fused deposition modelling (FDM) based 3D printing (MakerBot Replicator 2). An experiment took place in which samples of PLA and onyx were printed, both with and without a magnetic field present. This was done to see what effects, if any, the magnetic field had on the flow orientation of these materials when printed. The results from using a high-resolution optical microscopy and scanning electron microscopy showed that while carbon fibres within the Onyx had aligned in response to the magnetic field, the PLA samples were visibly unchanged by the magnetic field. The observations have been partially supported by theoretical calculations utilizing Multiphysics constitutive equations.

Study on Smoothing of Hole Wall Surface by Electron Beam Polishing under Control of Magnetic Field

A surface finishing method by large-area electron beam (EB) irradiation called EB polishing has been developed recently. Highly efficient surface smoothing of mold steels with planar shape can be performed by the EB polishing. However, it is difficult to smooth wall and bottom surfaces in hole shape by the EB polishing, since the EB tends to concentrate on entrance edge or upper inside wall of hole, and the energy density of EB on the wall and bottom surface of hole may decrease. Our previous study showed that the bottom surface could be smoothed by EB polishing under control of magnetic field around the workpiece. It is highly expected that EB can be also guided to the whole area of hole wall surface under appropriate control of magnetic field there.In this study, smoothing of hole wall surface by EB polishing under control of magnetic field around the workpiece was proposed. As a basic study for smoothing of hole wall surface, L-shaped workpiece was prepared by combining two stainless steel plates, and magnet was set under the workpiece. The electromagnetic field analysis results suggested that EB could be guided to the whole area of side surface by setting magnet under appropriate setting position, since magnetic force lines are uniformly distributed on whole area of side surface. In addition, magnetic flux destiny on the side surface more increases by setting a yoke made of steel on the magnet. The experimental results show that smoothed area with the surface roughness of less than 1.5μmRz can be obtained on the whole area of side surface. Therefore, the whole area of side surface can be uniformly smoothed by guiding the EB to the side surface under appropriate control of magnetic field.

Simple Approximation of the Magnetic Induction Inside High Voltage Overhead Transmission Lines

With the development of electrical power transmission networks, are resulted the increase and continuous consumption of various power production sources, this is what requires the large quantities of energy construction. The increased demand in electric power employment has generated an raised of operating voltage for transmission lines (HV and VHV). The high voltage overhead transmission lines create electric and magnetic fields, and therefore have elevated serious concern questions about their possible potential effects in human body and environmental great associated with the resulting higher levels of electromagnetic fields strength around these power lines. The accurate evaluation of extremely low frequency electromagnetic fields influences produced by the high voltage overhead power lines on human health and the environment are well very known and analysed in several research works and simulation study projects. In this paper we precise examine and present a methodology for plot the lateral profile of magnetic field distribution in close a three-phase overhead transmission line in single circuit flat horizontal configuration at height 1m above the ground level, In order show the essentials factors affecting in the magnetic fields intensity under and in the vicinity of high voltage overhead transmission line in any point of space surface and ground plane, the analytique calculation results of the lateral profile of magnetic flux density behaviour are obtained by program MATLAB software, which makes it possible better analyser and easy represent the transverse profile of the magnetic field around electric power transmission lines, the numerique simulation results are based in image method and the superposition theorem.

Whistler waves generated by nongyrotropic and gyrotropic electron beams during asymmetric guide field reconnection

Using a two-dimensional particle-in-cell simulation of asymmetric reconnection with a guide field whose strength is 0.3 times the reconnecting magnetic field, we study electron distribution functions and wave intensities in the diffusion region, focusing on the electron diffusion region (EDR). Wave activities with frequencies below the electron cyclotron frequency are observed, and these are whistler waves propagating almost anti-parallel to the magnetic field. The waves are concentrated near the magnetospheric separatrix away from the X line, but the wave activity also spreads through the EDR near the X line. The reconnection outflows are asymmetric in the outflow direction in the magnetospheric side, and the wave intensity is stronger in the side of the faster electron outflow. We study the whistler waves using the fast Fourier transform, analyses of electron velocity distribution functions, and the dispersion solver calculation. Along the magnetospheric separatrix in the stronger outflow side, highly anisotropic electron beams exist with super-Alfvénic drift speeds. The dispersion analysis shows that there are two modes: a temperature anisotropy mode and a beam mode. Outside the EDR, the whistler wave intensity is highest near the separatrix, but the wave intensity decreases if we move away from the separatrix toward the magnetic neutral line because of the increase in the electron population near zero parallel velocity. In the EDR, in the velocity plane perpendicular to the magnetic field, ring/crescent electron distribution functions are observed. Near the X-line, the wave power is enhanced where nongyrotropic electrons contribute to increase the perpendicular temperature anisotropy.

A Study on Correcting the Effect of Polarization Crosstalk in Full-Disk Solar Photospheric Magnetic Field Observations

Magnetography using magnetic sensitive lines is regarded traditionally as the main instrument for measuring the magnetic field of the whole Sun. Full polarized Stokes parameters (\(I\), \(Q\), \(U\), \(V\)) can be used to deduce the magnetic field under specific theoretical models or inversion algorithms. Due to various reasons, there are often cross-talk effects among Stokes signals observed directly by magnetographs. Especially, the circularly polarized signal \(V\) usually seriously affects the linearly polarized \(Q\) and \(U\) signals, which is one of the main errors in the value of the transverse magnetic field (parallel to the solar surface) that is related to \(Q\) and \(U\). The full-disk magnetograph onboard the Advanced Space based Solar Observatory (ASO-S/FMG) is designed to observe Stokes parameters and deduce the magnetic-field vector. In this article, the methods for correcting the effects of cross-talk \(V\) on \(Q\) and \(U\) based on the assumption of perfectly symmetric \(Q\) and \(U\) and anti-symmetric Stokes \(V\) profiles and a new method for reducing the crosstalk effect under observation mode of the FMG are developed. Through the test, it is found that the two methods are effective in cross-talk removal in the sunspot region and have better consistency. Additionally, the developed method can be applied to remove the cross-talk effect by using only one group of \(Q\), \(U\) and \(V\) images observed at one wavelength position.

A New Tectonic Model Between the Madagascar Ridge and Del Cano Rise in the Indian Ocean

AbstractThe southern Indian Ocean has several prominent aseismic ridges recognized as oceanic large igneous provinces (i.e., the Madagascar Ridge, Del Cano Rise, Crozet Plateau, and Conrad Rise) in the off‐axis areas of the Southwest Indian Ridge (SWIR). However, previously obtained magnetic survey lines are sparse and not correctly aligned with the seafloor spreading direction; thus, the detailed spreading history, including the formation of these aseismic ridges, remains an open question. We reconstructed the tectonic history of two segments between the Discovery II and Gallieni fracture zones in the SWIR using newly obtained magnetic data (total and vector magnetic field) and an open‐source magnetic data set. We revealed that the southern Madagascar Ridge and the Del Cano Rise once formed a single bathymetric high and separated by at least Chron 30y, which is quite different from the global age model. In addition, the rises may have formed before Chron 34y, assuming an extinct ridge south of the Del Cano Rise. The two rises have been recognized as having formed by Marion hotspot plume‐induced excess volcanism around the active spreading ridge of the SWIR, which can explain locally isostatically compensated thicker‐than‐normal crust. However, linear magnetic anomalies have not been observed across the main part of these rises, suggesting that magmatic activity controlled by seafloor spreading is unlikely. Like other aseismic ridges in the southern Indian Ocean, these two rises may possibly have been formed partly by continental fragments rather than plume‐induced excess volcanism.

Chiral Waves and Topological Novel States in Fermi

This first show was that the spin system, the two nearest neighbour spin in the Entanglement of measuring compliance by the ground conditions are achieved Berry stage to the relation when it is a closed path developed is. It noted the need to share the stage in a kind of geometric phase as explained to go to which any deformations involved is not and it’s the first Stiefel-Whitney class which is to Z_z–cohomology value takes. However for polarized fermions we can relate the exchange phase as the celebrated Berry phase as in this case the Z_z-cohomology becomes irrelevant and is consistent with the first Chern class which involves curvature. This follows from the depiction of a fermion as a scalar particle attached with a magnetic flux line. As in this framework the measure of entanglement of two nearest neighbor spins in a spin system given by concurrence is found to be associated with the Berry phase acquired by a spin state when it evolves in a closed path we can consider that entanglement is a consequence of Fermi statistics. It has been noted that in terms of quantum field theory, the berry phase is related to the perpetual inconsistency caused by the breaking of the perpetual symmetry. As mentioned earlier the quantization procedure of a fermion in the framework of Nelson’s stochastic quantization procedure introduces an internal variable which appears as a direction vector and gives rise to spin degrees of freedom. It's pointing to is that when a spin- 1 state of two spin 1/2 state is a Entangle system as considered to be that, the most widely covered state longitudinal elements with the matching it.

The Disk-Magnet Electromagnetic Induction Applied to Thermoelectric Energy Conversions

The thermoelectric energy conversion technique by employing the Disk-Magnet Electromagnetic Induction (DM-EMI) and improved DM-EMIs is shown, and possible applications to heat engines as one of the energy harvesting technologies are also discussed. The idea is induced by integrating irreversible thermodynamical mechanism of a water drinking bird with that of a Stirling engine, resulting in thermoelectric energy generation different from conventional heat engines. The current thermoelectric energy conversion with DM-EMI can be applied to wide ranges of temperature differences. The mechanism of DM-EMI energy converter is examined in terms of axial flux magnetic lines and categorized as the axial flux generator. It is useful for practical applications to macroscopic heat engines such as wind, geothermal, thermal and nuclear power turbines and heat-dissipation lines, for supporting thermoelectric energy conversions. The technique of DM-EMI will contribute to environmental problems to maintain clean and susceptible energy as one of the energy harvesting technologies.

Development of a hybrid raindrop generator based on tribo-nanotechnology

With the rapid development of modern industrial society, the energy crisis has become one of the urgent problems to be solved in modern society. Electric energy is one of the indispensable energy sources in the current society, and its production has always been concerned by more and more people. Based on the existing raindrop generators, a new raindrop generator, which can make full use of raindrop energy to generate electricity by means of triboelectric nanogenerators and cutting the magnetic line of force, is proposed to solve the current renewable energy power generation problem. Its brief construction model and its application prospects are given by this generator. Preliminary calculations show that the energy conversion efficiency of the hybrid system is about 50%, which improves the conversion efficiency of raindrop energy to electric energy and has good practical value.