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In this work, we study the ground state phase diagrams and the magnetic properties of the mixed spins (S = 3 ∕ 2 , G = 5 ∕ 2) of the silicene–germanene junction-like nanostructure. In the first step, the ground state phase diagrams have been established to show the more stable configurations corresponding in different physical parameter planes. Besides, we have used the Monte Carlo simulations in order to study the magnetization and the susceptibility as a function of the temperature and the exchange coupling interaction and external magnetic field effects. Finally, we have presented and discussed the hysteresis cycles for specific values of the studied physical parameters. [ABSTRACT FROM AUTHOR]

This work presents a study of the magnetic and magnetocaloric properties of mixed spins (σ = 1 , S = 3 / 2) in a Graphullerene-like nanostructure. Monte Carlo simulations (MCs) were conducted using the Metropolis algorithm in the Blume–Capel model. The ground state phase diagrams were established and illustrated for different physical parameters. Additionally, the corresponding magnetizations, susceptibilities, specific heat, Binder cumulant, magnetic and change entropies were examined versus temperature. The critical temperature was determined, and hysteresis cycles were presented for specific physical parameter values. The results suggest that the structure shows potential as a candidate for magnetic refrigeration. [ABSTRACT FROM AUTHOR]

A study of the magnetic properties of LaNi5 intermetallic compoundand and their effect on desorption reaction was carried out as a function of temperature. A Vibrating Sample Magnetometer (VSM) was used for the magnetic measurements and a Metal Hydrogen Reactor (MHR) supplied by a constant current through a coil was used for the hydrogen desorption reaction under the action of a magnetostatic field. Then, the hysteresis cycle, the first magnetization curve, the thermo-magnetization curves and the desorbed hydrogen mass were determined. The results showed that the application of a magnetic field corresponding to the magnetization at saturation Ms at a given temperature improved the hydrogen desorption reaction by the LaNi5.

The magnetic and magnetocaloric properties of the nano‐graphene monolayer structure consisting of mixed spins S = 3/2 and σ = 2 are studied by using Monte Carlo simulations. The ground‐state phase diagrams corresponding to several physical parameters are first discussed. The influence of the number of lattice sites on the total and partial magnetizations and the magnetic susceptibilities has been investigated. The critical temperature is deduced. The effect of exchange interaction, external magnetic, and crystal field on total magnetizations is studied. Magnetic hysteresis cycles are obtained. Specific heat change and magnetic entropy changes are inferred for several magnetic fields. Finally, the relative cooling power is determined. [ABSTRACT FROM AUTHOR]

Background: A deeper physical understanding of flame behaviour is necessary to make more reliable predictions about forest fire dynamics. Aims: To study the container size effect on the combustion characteristics of herbaceous fuels. Methods: Dead samples were put in cylindrical containers of different sizes, and were ignited at the lowest circumference of the basket in the absence of wind. Key results: In the growth phase, there is an anomalously fast relaxation of the fuel mass accompanied by a super-diffusion of the emitted gas species, whereas in the decay phase, there is a stretched exponential relaxation and the gas species sub-diffuse through the porous fuel. The crossover between these two anomalous processes occurs when the flame is fully developed. Thomas's correlation between flame height and fuel bed size, and the two-third power law dependence of the normalised flame height on the Froude number, fit the experimental data well. The flame height variation with burning rate exhibits a hysteresis cycle, implying the existence of memory effects on flame formation. Conclusions: The observed relaxation regimes and hysteresis cycle seem to drive fire dynamics and behaviour. Implications: Further investigation of the influence of the fuel geometry and porosity on these properties is necessary. Combustion properties of dead herbaceous fuels were studied in no-wind conditions. The phases of fire development are characterised by anomalous diffusion and relaxation processes. The variation of flame height with burning rate exhibited a hysteresis cycle induced by memory effects. These newly discovered physical mechanisms seem to drive fire dynamics. [ABSTRACT FROM AUTHOR]

The solar activity displays variability and periodic behaviours over a wide range of timescales, with the presence of a most prominent cycle with a mean length of 11 years. Such variability is transported within the heliosphere by solar wind, radiation and other processes, affecting the properties of the interplanetary medium. The presence of solar activity–related periodicities is well visible in different solar wind and geomagnetic indices, although their time lags with respect to the solar cycle lead to hysteresis cycles. Here, we investigate the time lag behaviour between a physical proxy of the solar activity, the Ca II K index, and two solar wind parameters (speed and dynamic pressure), studying how their pairwise relative lags vary over almost five solar cycles. We find that the lag between Ca II K index and solar wind speed is not constant over the whole time interval investigated, with values ranging from 6 years to ∼ 1 year (average 3.2 years). A similar behaviour is found also for the solar wind dynamic pressure. Then, by using a Lomb-Scargle periodogram analysis we obtain a 10.21-year mean periodicity for the speed and 10.30-year for the dynamic pressure. We speculate that the different periodicities of the solar wind parameters with respect to the solar 11-year cycle may be related to the overall observed temporal evolution of the time lags. Finally, by accounting for them, we obtain empirical relations that link the amplitude of the Ca II K index to the two solar wind parameters. [ABSTRACT FROM AUTHOR]

In this work, we study the ground state phase diagrams and the magnetic properties of the mixed spins (S-1, σ-7/2) of the Hexacene-like nanostructure. In the first step, the ground state phase diagrams have been established to show the more stable configurations corresponding to different physical parameters. Besides, the Monte Carlo simulations are used to investigate the effects of the temperature, the exchange coupling interactions, the crystal field, and the external magnetic field on the magnetization. Moreover, the hysteresis cycle behaviors have been investigated. It is found that the studied system exhibits two compensation temperatures (Tcomp1; Tcomp2) which depend on the exchange coupling parameters and the external magnetic field. [ABSTRACT FROM AUTHOR]

The paper studies the magnetic properties of the ternary FeCoxNi1–x alloy with mixed spins Fe(S = 2), Co(σ = 3/2) and Ni(q = 1), using Monte Carlo simulations under the Metropolis Algorithm. Firstly, we explore the ground state phase diagrams in order to identify all possible and stable configurations based on the minimisation of the system energy in different physical parameters planes. In addition, the magnetisations and the magnetic susceptibilities as a function of the temperature have been studied. Moreover, the effects of the crystal field, the exchange coupling parameters on the magnetizations and the hysteresis loops have been investigated for different values of the concentration ratio x of the Co atoms. It is found that the ratio x affects strongly the magnetisation, the susceptibility, the transition temperature and the hysteresis loops of the studied system. [ABSTRACT FROM AUTHOR]

The present work aims to investigate the physical properties of the ternary intermetallic MnXGe (X = Al and Ga) using density functional theory (DFT) and Monte Carlo simulation. The obtained ground state results reveal that MnXGe (X = Al and Ga) are stable in the ferromagnetic phase with a metallic character. The total magnetic moments of bulk structure (2D layer MnXGe(001)) are 2.13 μ B (2.325 μ B) and 2.30 μ B (3.28 μ B) for MnAlGe and MnGaGe, respectively, with the total moments coming mainly from the Mn atom. The ferromagnetic behavior is confirmed by the obtained density of state at the Fermi level and verified by the Stoner criterion. The mechanical, thermodynamic and transport properties show that the alloys are stable with brittle behavior and exhibit weak thermoelectric efficiency. The Monte Carlo simulation demonstrates that the critical temperatures (T C) are 540 K for MnAlGe(001) and 460 K for MnGaGe(001) with lattice size L = 30. • MnXGe (X = Al and Ga) are stable in the ferromagnetic phase with a metallic character. • The ferromagnetic behavior is confirmed by the Stoner criterion. • The mechanical and thermodynamic properties show that the alloys are stable. • The critical temperatures are of 540K for MnAlGe(001) and 460 K for MnGaGe(001). [ABSTRACT FROM AUTHOR]

The effects of heavy particle-wall interaction on a cylindrical plasma source discharge are investigated, through hybrid particle-in-cell/fluid simulations. The bulk plasma is considered quasineutral with isothermal electrons, and with no secondary electron emission from the walls. The neutral gas wall reflection model is shown to play a major role in determining the conditions for a self-sustained and stationary plasma discharge. A hysteresis cycle on the injection mass flow rate is found when neutrals deviate from a purely diffuse reflection at the walls, with the mass utilization efficiency changing up to 20% between purely specular and diffuse scenarios. However, as the ratio of ionization mean free path to macroscopic length is decreased, the neutral-wall reflection model becomes irrelevant. Finally, even small deviations from unity of the ion energy accommodation coefficient at the walls are seen to have a major impact on both the ion and neutral distribution functions, and ultimately the mass utilization efficiency. This behavior stresses out the importance of a precise experimental determination of this parameter for accurate simulations. [ABSTRACT FROM AUTHOR]

This article analyzes the magnetization rotation behavior of Fe-based soft magnetic materials and soft magnetic composites (SMMs and SMCs, respectively) samples. Room temperature measurements of the complex permeability until frequencies near 20 MHz and isothermal M(H) magnetization curves obtained from room to low temperatures (down to 20 K) show very similar soft magnetic behavior for both type of samples. Pulsed magnetic fields have been used to test their behavior under extreme conditions. Even with a substantial increase of the field variation sweeping rate and the temperature reduction (from 20 to 300 K) both types of materials keep their pronounced non-hysteretic behavior. However, zero field cooled–field cooled (ZFC–FC) curves with an applied field lower than 7.5 kOe show full irreversibility below room temperature, which indicates the existence of a broad distribution of barrier heights and seems to be in full contradiction with the obtained complex permeability and M(H) results. In this article, we aim to clarify this new and unexpected dual behavior. We suggest the existence of pinning barrier heights which are very sensitive to the variation of the magnetic field allowing the magnetization rotation with no losses while there are other barrier heights which need high values for the magnetic static fields to be removed when the temperature changes. [ABSTRACT FROM AUTHOR]

The aim of this paper is to investigate the magnetic properties of the MnBi magnetic systems by using the Monte Carlo simulation. Indeed, we analyzed the effect of the number of layers on the magnetic properties of the compound MnBi. The magnetization, the binder cumulant, the Curie temperature, and the hysteresis cycle are also calculated in this work. We used the free boundary conditions to simulate the properties of the studied system, and we presented the effect of multilayer numbers on the magnetic properties of MnBi films. Indeed, the indications that coercive field increases drastically with the increases multilayer numbers is consistent with the experimental facts. [ABSTRACT FROM AUTHOR]

The double perovskite Sr2CrIrO6 has very important characteristics for spintronic applications. It is a ferrimagnetic material distinguished by its high Curie temperature. This manuscript presents a model representing the double perovskite Sr2CrIrO6 in order to simulate and to predict its magnetic properties. This compound contains only two magnetic atoms, namely: Cr (S = 3/2) and Ir (σ = 2). Our simulations are done using the Monte Carlo method under the Metropolis algorithm. We present the behavior of the magnetization and the susceptibilities as a function of the temperature. Also, we discuss the effect of the physical parameters such as the coupling exchange interactions, the crystal field and the external magnetic field. To complete this study, we have presented the ground state by exposing the different phase diagrams in different planes of the physical parameters. Moreover, we establish the magnetic hysteresis loops of this compound. • We study the magnetic properties of the double perovskite Sr2IrCrO6. • We perform Monte Carlo simulations to investigate the magnetic properties of the double perovskite Sr2IrCrO6. • The effect of the physical parameters is studied and discussed. • The hysteresis loops are also presented for specific values of the physical parameters. [ABSTRACT FROM AUTHOR]

Abstract In the present work, we use Monte Carlo simulations (MCS) to study the ferrimagnetic of the mixed spin-1 and 3/2 Blume-Emery-Griffiths (BEG) model on a honeycomb lattice. The ground state phase diagram has been obtained for T = 0 whereas at non vanishing, total and partial magnetizations have been calculated. Moroever, we have presented the results of phase diagrams depending on different parameters: exchange coupling paramaters (r 1 and r 2), crystal field (d 1 and d 2), biquadratic coupling interaction (k) and external magnetic field (h). On the other hand, the compensation temperature and hysterisis cycle have been established. Highlights • Ground-state phase diagrams have been determined. • Magnetic properties of mixed spin-1 and spin-3/2 have been studied. • Critical temperature has been deduced. [ABSTRACT FROM AUTHOR]

A study of the magnetic properties of LaNi 5 intermetallic compoundand and their effect on desorption reaction was carried out as a function of temperature. A Vibrating Sample Magnetometer (VSM) was used for the magnetic measurements and a Metal Hydrogen Reactor (MHR) supplied by a constant current through a coil was used for the hydrogen desorption reaction under the action of a magnetostatic field. Then, the hysteresis cycle, the first magnetization curve, the thermo-magnetization curves and the desorbed hydrogen mass were determined. The results showed that the application of a magnetic field corresponding to the magnetization at saturation M s at a given temperature improved the hydrogen desorption reaction by the LaNi 5 ., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 Published by Elsevier Ltd.)

The use of friction dampers has been widely proposed for a variety of mechanical systems for which applying viscoelastic materials, fluid based dampers or other viscous dampers is impossible. An important example is the application of friction dampers in aircraft engines to reduce the blades’ vibration amplitudes. In most cases, friction dampers have been studied in a passive manner, but significant improvements can be achieved by controlling the normal force in the contact region. The aim of this paper is to present and study five control strategies for friction dampers based on three different hysteresis cycles by using the Harmonic Balance Method (HBM), a numerical and experimental analysis. The first control strategy uses the friction force as a resistance when the system is deviating from its equilibrium position. The second control strategy maximizes the energy removal in each harmonic oscillation cycle by calculating the optimal normal force based on the last displacement peak. The third control strategy combines the first strategy with the homogenous modulation of the friction force. Finally, the last two strategies attempt to predict the system’s movement based on its velocity and acceleration and our knowledge of its physical properties. Numerical and experimental studies are performed with these five strategies, which define the performance metrics. The experimental testing rig is fully identified and its parameters are used for numerical simulations. The obtained results show the satisfactory performance of the friction damper and selected strategy and the suitable agreement between the numerical and experimental results. [ABSTRACT FROM AUTHOR]

Using Monte Carlo simulations, we are studying the magnetic properties of Fe-doped CuO thin films. The total magnetizations and the susceptibilities are studied as a function of the effect doping, external magnetic field, and exchange coupling. The critical temperature is discussed as a function of the effect of iron concentration. On the other hand, we investigate the effect of increasing temperatures on the coercive field for a constant value of exchange coupling and a fixed concentration. The coercive magnetic field is found to decrease with increasing temperature values until reaching its null value. The effect of increasing the exchange coupling amount on the saturation magnetic field H is illustrated. A linear growth of the saturation magnetic field is found as a function of the exchange coupling interaction. To complete this study, we presented and discussed the magnetic hysteresis cycle loops. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate and determine the magnetic properties and the magneto-caloric effect of the system MnAs with the spin moment ( S = 2). To attain this aim, we first use Ab initio method to determine the density of the state and exchange couplings of the compound. This stage is followed by analysis and discussion of ground-phase diagrams, and then by examination of all stable phases. To investigate further the compound, we establish the magnetic properties and the magneto-caloric effect of the compound in question by Monte Carlo simulation method in the framework of the Ising model, and consequently, we achieve a number of results such as the determination of the magnetization, the susceptibility, the specific heat and the Binder's fourth-order cumulate of the order parameter, the plotting of the effect of the exchange coupling and temperature on the hysteresis loop behaviors, the calculation of the Binder's fourth-order cumulate of energy, and finally the isothermal magnetic entropy change, adiabatic temperature change and relative cooling power (RCP) for the different external magnetic fields. [ABSTRACT FROM AUTHOR]

The magnetic properties of zigzag metallic chains have been calculated based on the Monte Carlo simulation. The reduced transition temperatures and the magnetization have been obtained for different exchange interactions and for different crystal fields. The hysteresis cycle is obtained for different exchange interactions, temperatures and crystal field. The superparamagnetic behavior is obtained for a specific value of temperatures and crystal field. The second-order phase transitions are also observed. The obtained results are comparable with some given by experiment results and theoretical calculations. [ABSTRACT FROM AUTHOR]

This study evaluated a special type of stiffened plate that eliminates the weaknesses of previous stiffened systems, such as early out-of-plane buckling, low ultimate shear capacity, lack of symmetry and stability in the hysteresis curves of shear force-displacement. Consequently, folded sheet trapezoidal stiffeners connected to the basic plate by screws were used in order to obtain the values of the ultimate capacity and failure modes under quasi-static cyclic loads. An experimental analysis was performed on three types of steel plate shear walls including unstiffened by two different dimension stiffeners. The results indicated that the appropriate behavior in the stiffened wall using folded-shape specimens significantly amplified the ultimate capacity of the system and enhanced the symmetry and stability of the hysteresis curves of the force-displacement. Energy absorption also increased substantially. [ABSTRACT FROM AUTHOR]

In this paper, we study the magnetic properties of ferrimagnetic mixed spins with integer σ = 2 and half-integer S = 7 / 2 in a Blume–Capel model, using Monte Carlo simulations. The considered Hamiltonian includes the first nearest-neighbors and the exchange coupling interactions on the two sub-lattices. The effect of these coupling exchange interactions, in the presence of both the external magnetic field and the crystal field, are studied. The magnetizations and the corresponding susceptibilities are presented and discussed. Finally, we have interpreted the behaviors of the magnetic hysteresis of this model. [ABSTRACT FROM AUTHOR]

Electric steel is widely used for magnetic conversion of electrical energy such as in electric motors and power transformers. Electric steel sheets are cut using mechanical methods (such as punching) during manufacturing. These methods induce local plastic strains, which lead to overall degradation in magnetic performance. Plasticity and magnetic losses are physically related in electrical steel. It is impossible to measure the magnetic losses on the production line using standard methods. Non-destructive testing (NDT) based on magnetization mechanisms is a promising alternative, giving access to local plastic strains and indirectly to local magnetic losses. In this study, a setup was designed to stimulate the magnetization mechanisms separately while maintaining the same experimental conditions. The magnetization processes related to the domain wall kinetics were revealed to be more correlated to plastic strain. The magnetic incremental permeability hysteresis area and maximal value, and the coercivity associated with Barkhausen noise were found to be the best plastic strain indicators. Additional tests in an NDT context confirmed the correlations, the equal applicability of the proposed indicators, and their viability in predicting static hysteresis loss. [ABSTRACT FROM AUTHOR]

Using Monte Carlo simulations, we study the effect of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions in a bilayer olympicene structure, with mixed spins ( σ = 3/2 and S = 2) in the Blume-Capel model. The studied system is formed by two magnetic layers ( N and N ), separated by a number of non-magnetic layers (NM). We first elaborate the ground-state phase diagrams and then we found that from 4 × 5 = 20 phases possible, only 12 configurations are found to be stable. For low reduced temperature values, the partial magnetizations are found to be in good agreement with the corresponding ground-state phase diagrams. The critical temperature is displaced towards lower temperatures. This is due to the fact that the increasing of the number of non-magnetic layers increases the effect of the RKKY interaction. We have interpreted the behaviors of the magnetic hysteresis for this model. [ABSTRACT FROM AUTHOR]

• A very low coercive field (2 A/m) is already possible in the laboratory on an Fe50Ni50 alloy with a thickness of 0.8 mm, useful on a high precision torque sensor. • Additions of copper or chromium & titanium to effectively reduce the remanence and the coercive field of an Fe 50 Ni 50 alloy. • Tuned Curie point and Hopkinson peak drive new non-contact temperature sensing technology. Present and future applications for Fe 50 Ni 50 type alloys are dependent on an ever-improving mastery of the shape of the hysteresis cycle and/or the best use of these quantities when approaching the Curie point T c. A metallurgical solution exists to trigger anomalous grain growth at a thickness of 0.8 mm, allowing for the achievement of a coercive field less than 1.5–2 A/m which can further improve torque sensor accuracy. The lowering of J r to reinforce the safety and efficiency of certain electromechanical actuators is obtained by adding elements, interpreted as magnetoelastic effect related to lattice deformations. The joint selection of T c , the magnetic properties and the thermal and electromagnetic environmental conditions of the material will soon make it possible to achieve effective temperature regulations through the very nonlinear signature of the inductance as a function of temperature T at the approach of T c. [ABSTRACT FROM AUTHOR]

Coronary bypass surgery is a usual therapy for vessel-related diseases as several thousand of this kind of surgery are reported annually. In this surgery, saphenous vein, internal mammary artery or radial artery are grafted to replace coronary vessels. This research aims to evaluate viscoelastic properties of human saphenous vein vessel wall used in bypass surgery using a device designed in our laboratory. The most important feature of this device is its ability to simulate physiological conditions which exist inside humans' bodies. During experiments, variations in both vessel diameter and exerted pressure are recorded simultaneously. After performing measurements at frequencies near to heart beat frequency and finding loss and storage modulus for each frequency, it is found that, in the scanned frequency range, Kelvin model is the best approach to assess viscoelastic behavior of vessels. Remarkably, the results found in this research are in agreement with literature. [ABSTRACT FROM AUTHOR]

We present a new method for the accurate characterization of soft magnetic sheets using a permeameter based on the precise compensation of the magnetomotive force (MMF) drop in the flux-closing yoke. It has been developed in order to overcome the systematic uncertainty affecting the value of the magnetic field strength in single sheet testers when obtained, according to the standards, through the measurement of the magnetizing current. This phenomenon is more critical to high-permeability materials, because of the reduced MMF drop across the sample. While additional sensors and auxiliary windings have been proposed in the literature, a novel approach is demonstrated here, based on the use of the permeameter upper half yoke as the MMF drop sensor and of an auxiliary winding on the lower half yoke, implementing compensation. This solution, dispensing one from dealing with the usually small signal levels of the conventional MMF drop sensors (e.g., Chattock coils), provides the best results with the introduction of wedge-shaped magnetic poles, in order to accurately define the magnetic path length. The method is validated by the measurements of power loss, apparent power, and hysteresis cycles on non-oriented and grain-oriented Fe-Si steel sheets, which are compared with local measurements performed on the same samples using H-coil and B-coil across a uniformly magnetized region. [ABSTRACT FROM AUTHOR]

The magnetic properties of an Ising ferrimagnetic system based on a Dendrimer structure with the following mixed spins, σ = 2 and S = 5/2, have been investigated using the Monte Carlo simulations. The effect of the coupling exchange interactions in the presence/absence of both the external magnetic field and the crystal field on the critical temperature, the susceptibility and the magnetizations are studied. It is found that the critical temperature increases with increasing of the absolute value of exchange interactions. In addition, we have interpreted the behaviors of the magnetic hysteresis in this Dendrimer structure. [ABSTRACT FROM AUTHOR]