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Heavy cold ions at Mars are gravitationally bound to the planet unless some process provides energy to them. Observations show that cold (<20 eV) and dense (∼>1 cm−3) O+/O2+ ions with bulk velocities equal to energies ∼1 keV can reach deep into the nightside Martian magnetosheath. These ions are co‐located with a change of the sign of the sunward component of the magnetic field. This magnetic field topology implies the persistence of a localized planetary ions escape channel associated with draped magnetic field lines that are convecting tailward. The observed ion populations propagate approximately in the same direction as surrounding magnetosheath flow and are likely to be almost unheated ionospheric ions from low altitudes. The paper discusses planetary ion energization via Hall electric field originated from ions and electron separation associated with magnetic field curvature. Plain Language Summary: In‐situ observations above the nightside of Mars show the presence of localized dense planetary ion fluxes at altitudes exceeding 2,000 km and escaping from the planet at high energies, comparable to that of the solar wind. These fluxes are accompanied by the reversal of sunward component of magnetic field. Unlike most atmospheric escape channels, the reported phenomenon is characterized by an increase in heavy to light ions density ratio with the distance from the planet at the observed altitudes up to nearly 5,000 km, as well as an increase in overall plasma number density inside this escape channel relative to the ambient sheath environment. This behavior is consistent with acceleration process initiated by a bent magnetic flux tube. Key Points: Ions of different species gain similar energies in the Martian magnetosheath by Hall electric fields associated with magnetic curvatureA high concentration of ionospheric ions correlates with a near void of shocked solar wind protons and a magnetic field reversalNumber density at the reversal increases with distance from Mars in comparison to the surrounding sheath at least till two Martian radii [ABSTRACT FROM AUTHOR]

Summary: This paper presents a low dropout regulator (LDO) with a wide input voltage range and high power supply rejection (PSR) for Hall sensor front‐end circuits, which is fabricated with a 0.18 μm BCD process. A topology in which a closed‐loop charge pump biases the gate of two‐stage cascode NMOS pass transistors is proposed to increase immunity to electromagnetic interference (EMI) capability for automotive applications. Furthermore, a power‐down protection circuit is proposed to maintain the reliability of the system, and a novel implementation of the charge pump unit is presented to improve the influence of the body effect. Detailed derivation regarding the analyses of the simplified small‐signal model of the closed‐loop charge pump, the loop stability, and the PSR at various frequency bands is given. Simulation and measurement results show that the proposed LDO can operate with the input voltage from 5 to 40 V, providing up to 60 mA current drive capability, and its minimum operating voltage is 2.5 V with a 10 mA load capacity. Moreover, results verify that measured PSR is better than −45 dB at 1.5 kHz, and measured PSR is better than −30 dB at 15 MHz. The results confirm that the obtained parameters of line and load regulations are significantly improved to 1.86 mV/V and 1.75 mV/mA, respectively. [ABSTRACT FROM AUTHOR]

This paper presents a dual gravity model for a (2+1)‐dimensional system with a limit on finite charge density and temperature, which will be used to study the properties of the holographic phase transition to paramagnetism‐ferromagnetism in the presence of Horndeski gravity terms. In our model, the non‐zero charge density is supported by a magnetic field. As a result, the radius ρ/B$\rho /B$ indicates a localized condensate, as the Horndeski gravity parameter is increased, that is represented by γ. Furthermore, such condensate shows quantum Hall‐type behavior. This radius is also inversely related to the total action coefficients of our model. It is observed that increasing the Horndeski parameter decreases the critical temperature of the holographic model and leads to the harder formation of the magnetic moment at the bottom of the black hole. However, when removing the magnetic field, the ferromagnetic material presents a disorder of its magnetic moments, which is observed through the entropy of the system. The authors also found that at low temperatures, spontaneous magnetization and ferromagnetic phase transition. [ABSTRACT FROM AUTHOR]

This paper deals with obtaining some new characterizations on the dynamics of the moving charged particle acting under particular forces in the three‐dimensional space. In this perspective, we have enlarged the research of magnetic curves and associated Killing magnetic fields by adding the Fermi–Walker parallelism and derivative. By doing this, we investigate the Hall–Killing–Fermi effect on the charged particle, then we define new types of Fermi–Walker magnetic curves corresponding to the Killing magnetic field. We carefully construct the Fermi–Walker character of the magnetic field to prove the parallelism of the magnetic trajectories and uniformly accelerated motion of the charged particle. It leads to defining a very special family of magnetic fields, that is, Fermi–Walker uniform magnetic fields. Moreover, we use the Killing feature of the magnetic field to show that the Frenet–Serret scalars and quasislopes of the magnetic curves must meet particular differential equations that lead to obtaining some geometric interpretations of the magnetic trajectories. Last but not the least, both of these two characters allow us to define Killing and Fermi–Walker electric vector fields influencing the motion of the charged particle experiencing the Lorentz force in the three‐dimensional setting. [ABSTRACT FROM AUTHOR]

In this paper, we examine the effect of thermal radiation on rotating magnetohydrodynamic two liquid flows of ionized gasses past horizontal channel under slip and Hall conditions. The fluids in the two zones are considered to be immiscible, incompressible, and electrically conducting with various viscosities, thermal and electrical conductivities. We derive the exact solutions for the temperature profiles and coefficients of heat transfer rate at the plates in the two zones by solving governing equations in the presence of slip‐regime analytically. The temperature fields have been figured for various sets of values of the involved governing characteristics to analyze the behavior of heat transport. It has been noted that there is an enhancement in the temperature profile as the slip parameter rises for fixed values of the remaining parameters. Also, stimulations occur in the temperature field, with an increment in Taylor's number. This study may have some significant implementations in biomedical science such as destroying cancer cells during the drug delivery treatment, polishing damaged internal cavities, heart valves, and so forth. [ABSTRACT FROM AUTHOR]

Tunability of topological photonic structures opens a new avenue for photonics research. The rich physical characteristics of the topological photonics have great significance in practical implementations. In this paper, multi‐type topological states are demonstrated in higher‐order photonic topological insulators based on Kagome metal lattices. By stretching or rotating Kagome metal lattices, two types of topological insulators are obtained, and multi‐type topological states are observed. By stretching Kagome metal lattices, a 1D topological edge state and two types of higher‐order topological corner states (corresponding to a traditional higher‐order topological corner state based on nearest‐neighbor coupling and a new higher‐order corner state caused by long‐range interactions) are obtained in a classical quantization of dipole moments higher‐order topological insulators. By rotating Kagome metal lattices, dual‐band higher‐order valley‐Hall topological insulators are achieved with nodal ring degeneracy. Odd‐type and even‐type topological states are obtained. Achieving reconfigurable, multi‐type, and multi‐band topological insulators by using a single structural unit provides interesting insights into topological photonics and provides an unconventional approach to explore photonic systems and condensed matter physics. [ABSTRACT FROM AUTHOR]

Calibration is the backbone of any sensor and measurement philosophy. The conventional calibration techniques for electrical parameter measurement using nonlinear sensors are affected by the repeating analogue signals and lead to errors in measurement. This research paper investigates different regression‐based mathematical models to calibrate the Hall sensor for measuring RMS and the fundamental frequency. The novelty of this research work lies in the feature‐based input modelling to measure RMS current and frequency with an error of 3.37e‐12% and 7.61e‐9%, respectively. The conventional Fourier transform method is compared with six different bio‐inspired metaheuristic algorithms to estimate the frequency components of the analogue signal received from the measurement setup. Apart from the conventional sine waveforms, this paper investigates sawtooth and square waveforms as the periodic signals for determining the frequency components. The results from the comparison study show that the Whale Optimization Algorithm exhibits 1.25% lesser error whilst predicting the features in measured frequency components. Apart from this, the paper identifies a unique combination of features that effectively measures the instantaneous electrical parameter with RMSE, NRMSE, and R2 value of 158.8, 0.51, and 0.44, respectively. Experimentally it is found that the decision tree and random forest regression models calibrate the Hall sensor with 93% less error than their linear and polynomial counterparts. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the effects of Hall current, radiation absorption and diffusion thermo on unsteady magnetohydromagnetic free convection flow of a viscous incompressible electrically conducting and chemically reacting second‐grade fluid past an inclined porous plates in the presence of an aligned magnetic field, thermal radiation, and chemical reaction. An exact analytical solution of the governing equations for fluid velocity, fluid temperature, and species concentration subject to appropriate initial and boundary conditions is obtained using the perturbation technique. Expressions for shear stress, rate of heat transfer, and rate of mass transfer at the plate are derived. The numerical values of primary and secondary fluid velocities, fluid temperature and species concentration are displayed graphically, whereas those of shear stress and rate of mass transfer at the plate are presented in tabular form for various values of pertinent flow parameters. In addition, the skin friction on the boundary, the heat flux expressed in terms of the Nusselt number, and the rate of mass transfer described in the Sherwood number are all derived, and their behavior is studied computationally. It can be deduced that an increase in radiation absorption and hall current parameters over the fluid region increases the velocity produced. The resulting velocity continually increases to a very high level, with contributions coming from thermal and solutal buoyancy forces. Skin friction may decrease by manipulating the rotation parameter, but the Hall effect can worsen it. When the parameter for the chemical reaction increases, there is a concomitant rise in the mass transfer rate. [ABSTRACT FROM AUTHOR]

Summary: Electronic commutator in Brushless DC motor (BLDC) drives decides the sequence of driving current through the stator windings based on the rotor position sensed by the three Hall position sensors. If any fault occurs in the Hall sensors, it will result in a faulty driving sequence of rotors and the motor will stall. This paper investigates an artificial intelligence‐based Fault Diagnosis and Compensation (FDC) system for correcting up to two position sensor failures in trapezoidal back EMF BLDC motor drives. The proposed fault‐tolerant system is a simple, fast, and efficient method to diagnose and reconstruct the commutation signals using the existing processor‐based commutator arrangements. An Artificial Intelligence algorithm is developed to estimate the correct switching sequence in the absence of up to two Hall sensor signals while the motor is running. This supervised learning network is advantageous as it is added as an additional control algorithm with the existing control algorithm for BLDC motor. The simulation and hardware results showcase the effective performance of the proposed algorithm for different Hall sensor fault conditions. [ABSTRACT FROM AUTHOR]

The anomalous Hall effect (AHE) is a quantum coherent transport phenomenon that conventionally vanishes at elevated temperatures because ofthermal dephasing. Therefore, it is puzzling that the AHE can survive in heavy metal (HM)/antiferromagnetic (AFM) insulator (AFMI) heterostructures at high temperatures yet disappears at low temperatures. In this paper, an unconventional high-temperature AHE in HM/AFMI is observed only around the Néel temperature of AFM, with large anomalous Hall resistivity up to 40 nQ cm is reported. This mechanism is attributed to the emergence of a noncollinear AFM spin texture with a non-zero net topological charge. Atomistic spin dynamics simulation shows that such a unique spin texture can be stabilized by the subtle interplay among the collinear AFM exchange coupling, interfacial Dyzaloshinski-Moriya interaction, thermal fluctuation, and bias magnetic field. [ABSTRACT FROM AUTHOR]

It is difficult to separate Luer lock adapters during the external ventricular drainage (EVD) since they are often connected by a threaded connection, and the infusion needle put into the patient's body gets pulled out when extubation occurs unexpectedly. The paper described a new magnetic connection assembly made up of ring magnetic permanents and a Hall sensor that could be used to replace Luer lock adapters for quicker disconnection and reconnection of the drainage catheter. For the design and analysis of the device, the finite element method magnetics (FEMM) was used to estimate the size of magnetic permanents and the best detection site of the Hall sensor for detecting whether the magnetic permanents were closely attracted and/or pulled apart. Then an experiment was conducted to confirm our findings. Both simulation and experiment revealed that a pair of hollow cylindrical magnetic permanents, each with height 10 mm, outer diameter 8 mm, and inner diameter 4 mm, could achieve the same force as the Luer lock adapters held, and that the best Hall sensor detection position was in the middle of the permanent magnets, with a radial distance of about 2 mm. [ABSTRACT FROM AUTHOR]

The focus of this paper is to examine the heat and mass transport behavior of transient magnetohydrodynamics second‐grade fluid (elastico‐viscous fluid) flow within a vertical channel bounding the porous regime with the Hall phenomenon and induced magnetic field (IMF). The flow system consists of a strong transverse magnetic field that gives rise to the Hall phenomenon and IMF. The right vertical surface of the channel is conducting and oscillations in its plane in the vertical direction while the left vertical surface of the channel is nonconducting and stationary. The suitable dimensionless setup transforms the flow model into a simplified comparable model which is solved analytically with the assistance of the method of separation of variables. Numerical computation is performed with the aid of MATHEMATICA software to explore the results from the analytical solutions. The results of the investigation are helpful in analyzing the nature of the elastic‐viscous fluids. A noteworthy result noted from the investigation is that there appears a reverse flow in the direction of normal flow when the magnetic interaction parameter is large. For the small magnetic interaction parameter, such a flow is not seen. Hall current reduces the strength of the principal IMF and induces the strength of the secondary generated magnetic field. Furthermore, it is explored that the elastico‐viscous nature of the second‐grade fluid has a tendency of enhancing the principal flow and principal‐produced magnetic field. [ABSTRACT FROM AUTHOR]

Accurate position signals are essential for a vector control system. To obtain accurate position signals, high‐precision position sensors such as optical encoder and resolver are employed. However, they are usually restricted by the environmental condition and cost. Linear Hall‐effect sensors, possessing tiny size, light weight and low cost, are usually used to detect position signals. However, the position signals detected by linear Hall‐effect sensors in low cost conditions always contain a large part of high‐order harmonics, which will decrease the validity and reliability of sensor measurement. In this paper, to eliminate the influence of harmonics, a short‐distance harmonic suppression method without any low‐pass filter is proposed. The proposed method utilises three linear Hall‐effect sensors displaced a certain electrical angle to dissolve the position signal. Through simulation analysis and experimental verification, the proposed method has been proven to be effective in suppressing the third‐order and fifth‐order harmonics. [ABSTRACT FROM AUTHOR]

Since the confirmation of long‐range magnetic ordering in 2D materials, much effort has been devoted to finding more 2D magnetic materials with high Curie temperature (TC) and tunable physical properties. Most of the 2D magnets realized to date are based on van der Waals (vdW) materials, but recently synthesized 2D non‐vdW ultrathin materials have revealed an alternative direction for the discovery of novel 2D magnets. In this paper, a family of 2D non‐vdW Cr2TexSe3−x compounds is proposed. All Cr2TexSe3−x compounds are predicted to be energetically favorable and air stable, suggesting experimental feasibility, and long‐term stability. Compared to other non‐vdW materials, Cr2TexSe3−x compounds have superior oxidation resistance. Moreover, they exhibit obvious composition‐dependent magnetic ordering, which originates from the competition between interlayer direct antiferromagnetic exchange and ferromagnetic superexchange. Among them, half‐metals Cr2Te3 and Cr2TeSe2 exhibit robust ferromagnetism with high TC values of 396 and 261 K, respectively. Additionally, 2D Cr2TeSe2 shows a sizable anomalous Hall conductivity of 6237 Ω cm−1. The present results enrich the database of 2D non‐vdW magnets and provide fundamental understanding about the composition‐induced magnetic phase transition, which may be of use in spintronic applications. [ABSTRACT FROM AUTHOR]