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This study focuses on construction of novel enhanced metaheuristic algorithm using a modified opposition‐based learning technique and the hunger games search algorithm. The proposed modified opposition‐based hunger games search (mOBL‐HGS) algorithm is aimed to be used as an efficient tool to tune a fractional order proportional‐integral‐derivative (FOPID) controller in order to control a magnetic ball suspension system with greater flexibility. The challenging benchmark functions from CEC2017 test suite are used to confirm the greater performance of the proposed mOBL‐HGS algorithm. The proposed mOBL‐HGS algorithm is also utilized to reach the optimum values of a FOPID controller employed in a magnetic ball suspension system in order to demonstrate its capability in terms of a complex real‐world engineering problem. The latter case is confirmed through comparative evaluations of statistical analysis, convergence profile, transient response, frequency response, disturbance rejection, and robustness. The demonstrated results confirm the greater ability of the proposed approach to control a magnetic ball suspension system. [ABSTRACT FROM AUTHOR]

Arrays of trapped ultracold molecules represent a promising platform for implementing a universal quantum computer. DeMille [Phys. Rev. Lett. 88, 067901 (2002)] has detailed a prototype design based on Stark states of polar 1Σ molecules as qubits. Herein, we consider an array of polar 2Σ molecules which are, in addition, inherently paramagnetic and whose Hund's case (b) free-rotor pair-eigenstates are Bell states. We show that by subjecting the array to combinations of concurrent homogeneous and inhomogeneous electric and magnetic fields, the entanglement of the array's Stark and Zeeman states can be tuned and the qubit sites addressed. Two schemes for implementing an optically controlled CNOT gate are proposed and their feasibility discussed in the face of the broadening of spectral lines due to dipole-dipole coupling and the inhomogeneity of the electric and magnetic fields. [ABSTRACT FROM AUTHOR]

In this work, we report on the development and implementation of a new scheme for efficient calculation of indirect nuclear spin-spin couplings in the framework of four-component matrix Dirac-Kohn-Sham approach termed matrix Dirac-Kohn-Sham restricted magnetic balance resolution of identity for J and K, which takes advantage of the previous restricted magnetic balance formalism and the density fitting approach for the rapid evaluation of density functional theory exchange-correlation response kernels. The new approach is aimed to speedup the bottleneck in the solution of the coupled perturbed equations: evaluation of the matrix elements of the kernel of the exchange-correlation potential. The performance of the new scheme has been tested on a representative set of indirect nuclear spin-spin couplings. The obtained results have been compared with the corresponding results of the reference method with traditional evaluation of the exchange-correlation kernel, i.e., without employing the fitted electron densities. Overall good agreement between both methods was observed, though the new approach tends to give values by about 4%-5% higher than the reference method. On the average, the solution of the coupled perturbed equations with the new scheme is about 8.5 times faster compared to the reference method. [ABSTRACT FROM AUTHOR]

We report the implementation of nuclear magnetic resonance (NMR) shielding tensors within the four-component relativistic Kohn-Sham density functional theory including non-collinear spin magnetization and employing London atomic orbitals to ensure gauge origin independent results, together with a new and efficient scheme for assuring correct balance between the large and small components of a molecular four-component spinor in the presence of an external magnetic field (simple magnetic balance). To test our formalism we have carried out calculations of NMR shielding tensors for the HX series (X = F, Cl, Br, I, At), the Xe atom, and the Xe dimer. The advantage of simple magnetic balance scheme combined with the use of London atomic orbitals is the fast convergence of results (when compared with restricted kinetic balance) and elimination of linear dependencies in the basis set (when compared to unrestricted kinetic balance). The effect of including spin magnetization in the description of NMR shielding tensor has been found important for hydrogen atoms in heavy HX molecules, causing an increase of isotropic values of 10%, but negligible for heavy atoms. [ABSTRACT FROM AUTHOR]

This study addresses double-sided stationary stators in a linear electric generator with similar operation to a linear oscillatory motion electric machine. The plate mover in the linear electric generator's double-sided stationary stators is powered by the acoustic power output of the thermoacoustic engine's acoustic line. The main originality of this structure resides in the linear guidance used for the moving part. The mover is made up of a plate of sandwich magnets between two stators. This plate is in magnetic balance between the two stators through a controlled friction device. [ABSTRACT FROM AUTHOR]

Not long ago, certain iron ore processing plants in Brazil were unable to efficiently recover iron ore fines and, as a result, operated only with high grade iron ore. For this reason, material stored in some iron ore tailings dams have considerable amounts of iron content with a potential to produce pellet feed fines through a concentration process. This study presents the results of magnetic concentration tests carried out on samples from four iron ore tailings dams located in Minas Gerais, named as A, B, C and D. The average iron content is 54% for A dam, 36% for B dam, 49% for C dam, and 58% for D dam. This material had a significant amount of ultra-fine particles, with more than 50% below 0.045mm for all dams, particularly the A and D dams, which present more than 80% of the below 0.045mm on average. Magnetic concentration tests were conducted on bench and pilot scales. The resulting concentrates showed the following average iron content: 66% for dam A, 63% for dam B, and 67% for dams C and D, with a mass recovery of 42% for dam A, 38% for dam B, 75% for dam C, and 63% for dam D. These results confirm the potential for pellet feed production from tailings dams through magnetic concentration. [ABSTRACT FROM AUTHOR]

Abstract There have been extensive reports on the phase diagram and magnetic properties of the Al-Co-Ni system. However, a systematic investigation of the Curie temperatures in this alloy system is still lacking. In this work, the Curie temperature in the fcc phase field of the Al-Co-Ni alloy system was studied using a simultaneous magnetic balance and differential scanning calorimeter method. The Curie temperature contour map was constructed according to the measured results and an Exponential2D fitting function using Originlab® was obtained, which provides a useful tool for estimating the Curie temperature in Al-Co-Ni alloys. The experimental technique provides a novel method of detecting phase transformations and precipitation based on analyzing the heat effects and magnetic behavior of the alloys in the presence or absence of a magnetic field. Experimental results from this technique provide the first evidence for the occurrence of a Nishizawa horn in this system as predicted using Thermo-Calc®. Graphical abstract Image 1 Highlights • The Curie temperature in Al-Co-Ni system was measured using combined TG-DSC method. • A fitting function was proposed for estimating Curie temperature in Al-Co-Ni alloys. • This technique provides a novel method of detecting phase transformations. • Experimental results provide the first evidence for Nishizawa horn in this system. [ABSTRACT FROM AUTHOR]

Abstract The high-resolution aeromagnetic data of parts of the lower and middle Benue Trough (Nigeria) has been analyzed to estimate the magnetic basement depths using the scaling spectral method. Magnetic basement depths beneath the area of study are found dominantly between 3 km and 5 km with the 3 km depths corresponding to the areas of Ogam/Obangedde, Ugba and Makurdi whereas the 5 km depths are found around the areas of Abakaliki, Gboko, Igumale, Oturkpo, Gbajimba and Arufu. Shallower magnetic basement depths of 1 km are estimated around Ebeel and the area of Ugba and 2 km depths from the areas of Akwana and Otukpa. We have also calculated few higher values of 6 km around the areas of Igbor, near Igumale and the area north of Oturkpo, 7 km depths at Onuweyi and Ikumbur areas and 9 km depths near Makurdi, Yandev area and east of Ogoja area. Our estimated basement depths are in good agreement with the results of the earlier studies in the region. The obtained scaling exponent values are found between 0 and 3 and are not correlated everywhere with the estimated depths and the geology of the region. That may be because of the effects of adjacent geological units and the presence of the volcanic intrusions within the region. Highlights • The magnetic basement of 1–9 km is calculated beneath the region of study. • The basement depths beneath the region of study are dominantly between 3 km and 5 km. • Scaling exponent between 0 and 3 for horizontal distribution of magnetic sources are calculated within the region of study. • The scaling exponent value of 0 suggests the uncorrelated distribution of magnetic sources. • The non-correlation of the estimated scaling exponent values suggests the complex and unstable nature of the region. [ABSTRACT FROM AUTHOR]

In a preliminary design study for a small‐angle slot (SAS) divertor configuration suitable for DIII‐D double‐null advanced tokamak (AT) plasmas, a conceptual “SAS 2” slot divertor configuration has been modelled with SOLPS‐ITER. A balanced double‐null equilibrium, representing an H‐mode AT plasma, is employed, with 5 MW neutral beam input power. In simulations with fully recycling walls and no pumping, an up–down‐symmetric open divertor geometry is compared with the SAS 2 configuration. In density scans without electric or magnetic drifts, the upstream separatrix electron density needed to achieve detachment at both target strike points (ne, sep, det.) is ∼35% lower in SAS 2 than in the open configuration, with ne, sep, det. = 1.66 and 2.59 × 1019 m−3, respectively. With drifts, the same ∼35% difference remains, but detachment density for each configuration is shifted up by ∼15%, giving ne, sep, det. = 1.94 and 2.99 × 1019 m−3, respectively. Cryopumping is modelled for the SAS 2 divertor, and with a pump duct deep in the upper slot on the common‐flux side, detachment density is shifted up by ∼15–20%. Strong pumping in the upper slot delays detachment there compared with the lower slot, regardless of drift direction. This research sets the stage for future modelling that would explore more sophisticated cryopumping configurations, and sensitivity of divertor performance to changes in magnetic balance and input power. [ABSTRACT FROM AUTHOR]

In this paper, the magnetic model NGDC-720-V3 is used to investigate the distribution of crustal magnetic anomaly and the depth of Curie surface in west Himalayan syntaxis and its adjacent area. The Curie surface is compared with regional heat flow, the Moho, and seismicity. The results show that the magnetic anomaly and Curie surface are both consistent with the regional tectonic setting. Tarim craton, Tadjik Basin, and Indian Plate have positive magnetic anomaly and a Curie surface deeper than 36 km, corresponding to low heat flow there. In contrast, orogenic belts such as west Himalayan syntaxis, Tianshan Mountain, Afghanistan, and Tibetan Plateau have negative anomaly and a Curie surface shallower than 32 km, corresponding to high heat flow. The north of the syntaxis presents a positive anomaly on the surface, resulting from Ferghana Basin, while the negative anomaly in large depth is probably associated with the subduction of the slab and the resulting heat. The depth of the Curie surface has an inverse relationship to the Moho depth, which is attributed to temperature and isostatic balance. The distribution of earthquakes with epicenter deeper than 100 km clearly suggests the subduction of the Indian plate deep down to the asthenosphere and the deep earthquakes were caused by shear motion within the subducting slab. [ABSTRACT FROM AUTHOR]

Zr–Ag composites were fabricated to decrease the magnetic susceptibility by compensating for the magnetic susceptibility of their components. The Zr–Ag composites with a different Zr–Ag ratio were swaged, and their magnetic susceptibility, artifact volume, and mechanical properties were evaluated by magnetic balance, three-dimensional (3-D) artifact rendering, and a tensile test, respectively. These properties were correlated with the volume fraction of Ag using the linear rule of mixture. We successfully obtained the swaged Zr–Ag composites up to the reduction ratio of 96% for Zr-4, 16, 36, 64Ag and 86% for Zr–81Ag. However, the volume fraction of Ag after swaging tended to be lower than that before swaging, especially for Ag-rich Zr–Ag composites. The magnetic susceptibility of the composites linearly decreased with the increasing volume fraction of Ag. No artifact could be estimated with the Ag volume fraction in the range from 93.7% to 95.4% in three conditions. Young's modulus, ultimate tensile strength (UTS), and 0.2% yield strength of Zr–Ag composites showed slightly lower values compared to the estimated values using a linear rule of mixture. The decrease in magnetic susceptibility of Zr and Ag by alloying or combining would contribute to the decrease of the Ag fraction, leading to the improvement of mechanical properties. [ABSTRACT FROM AUTHOR]

The article presents an overview of the history of the magnetic method in archaeological research, from its first use in 1958 in England through the 1990s. Brief presentations of the history of research using this method have already appeared in general works dedicated to archaeological geophysics, but merely as introductory chapters, which have focused on initial stages of the application of particular methods (chiefly magnetic and electrical resistivity) and highlighted achievements in the field in Western Europe, primarily the UK. In the present text, the author has also included the history of the use of the magnetic method in other parts of Europe (Central and Eastern Europe) and on other continents. He analyzes technological changes in the instruments used for research, from the proton magnetometer and magnetic balance to the increasingly advanced fluxgate and optically pumped magnetometers. He also examines the changes in measurement technology and data processing that have occurred and the factors shaping the development of the method. [ABSTRACT FROM AUTHOR]

We studied the electronic structure of Fe- or Co-doped Sr2IrO4, using density functional calculations including spin-orbit coupling and electron correlation. Our results show that upon the doping (x < 0.5), a Fe3+-Ir5+ or Co3+-Ir5+ charge state appears on the Ir4+ matrix. Contrary to the effective j = 1/2 state of the Ir4+ ion due to a strong spin-orbit coupling, the Ir5+ (5d4, t428 ) ion could form a closed jtff = 3/2 subshell and hence behave like a singlet. The Fe3+ and Co3+ ions are both in a high-spin state, with their respective S = 5/2 and 2, and the Co3+ ion also carries a big orbital moment. This coupled charge-spin-orbital state, assisted by spin-orbit coupling and electron correlation, gives rise to an insulating behavior of Fe- or Co-doped Sr2IrO4 and accounts for their varying magnetic moments. [ABSTRACT FROM AUTHOR]

Aiming to find magnetic states in the Mn+1AXn phases, we measured the magnetic susceptibility, the resistivity, and nuclear magnetic resonance of Cr2GaX (X=N and C). Zero-field and longitudinal-field muon spin relaxation experiments were also applied to Cr2GaN. A magnetic phase transition, most probably to the spin-density-wave (SDW) state, has been found in Cr2GaN at TN=170 K in contrast to the Pauli paramagnetism in the carbide counterpart Cr2GaC. The origin of the SDW transition is interpreted in terms of possible Fermi-surface nesting in the two-dimensional-like electronic structure. [ABSTRACT FROM AUTHOR]

Here, I extend my last work about the origin of the pseudogaps in underdoped cuprates (Dayan in cond-mat, ) to include the mechanism of superconductivity. This is done by adapting the formalism of the double correlations in systems with nested Fermi surfaces to the semi one-dimensional system of strings of holes. It is proposed that magnetic interaction is crucial for the establishment of the pseudogap and the high temperature superconductivity. It is shown that superconductivity disturbs the completeness of the strings of holes, and creates fluctuations in them. This, in turn, reduces the magnetic interaction and the pseudogap order. [ABSTRACT FROM AUTHOR]

In order to understand the aerodynamic properties of Japanese arrows, several types of shafts without fletching and various types of Japanese arrows were examined in a low-speed wind tunnel equipped with the JAXA 60-cm magnetic suspension and balance system. The main component of drag acting on the shaft is viscous drag from the boundary layer. This viscous drag can be evaluated analytically. A simple new method to estimate the effects of fletching on the lift of the arrow was proposed in which we found that lift is proportional to the angle of attack of the arrow but not to the rotation speed or angle. Time history results for the lift on rotating arrows in the magnetic suspension and balance system indicate that this method effectively estimates the lift on an actual rotating arrow in flight. The lift and pitching moment were mainly generated by fletching, and the drag from the fletching was similar in magnitude to that of the arrow shaft. For Japanese bamboo arrows tested with a field point, the drag, lift, and pitching moment coefficients were evaluated to be in the ranges of 3.5-3.7, 0.4-0.8, and −0.15 to −0.25, respectively, at Reynolds numbers of an arrow in flight. [ABSTRACT FROM AUTHOR]

In this paper, the unbalanced magnetic forces which act upon the rotor of a salient-pole synchronous generator due to eccentric motion of the rotor shaft in the presence of magnetic field in no-load and loaded condition are calculated using the finite-element method. The displacement of the rotor is modeled using the actual shaft orbit measured on a 5-MVA salient-pole generator driven by a gas turbine in a cogeneration plant. The influences of the stator winding parallel paths and the rotor damper winding on attenuation of unbalanced magnetic pull are analyzed using the finite-element method. It is shown that under linear conditions the correlations between separate harmonic components of the shaft orbit, the resulting harmonic components of the unbalanced magnetic pull and the induced stator winding currents can be established in both the no-load and loaded condition. [ABSTRACT FROM PUBLISHER]

This paper introduces the condition of balanced operation to solve problems caused by an unbalanced magnetic field when a single-phase line start permanent magnet motor operates in steady-state. Using an equivalent circuit on the basis of symmetric field theory, conditions are found for balanced operation at rated conditions and for copper loss minimization in the stator. The initial model is modified applying these two conditions from commercial model. In addition, an optimum design is implemented in order to improve starting characteristic. In an optimum design process, the sampling points are chosen by latin hypercube sampling and from the results, an approximation model is made by the radial basis function. Then the optimization results are obtained by a genetic algorithm. The validity of the proposed design is verified by confirming the efficiency, torque ripple, ohmic loss of the rotor, and starting characteristic through time step FE-analysis and experimental results. [ABSTRACT FROM AUTHOR]

Permanent magnet linear synchronous motor (PMLSM) has been successfully applied in various industry fields due mainly to excellent dynamic characteristics and accurate positioning capability. However, PMLSM suffers force ripple, which deteriorates controllability, and it is often considered to be an expensive linear drive mechanism since it requires a large amount of rare-earth permanent magnet (PM) material in the stationary part. This paper introduces and analyzes a new design of winding and mover arrangement for doubly salient permanent magnet linear synchronous motor (DSPMLSM). The proposed design reduces force ripples, magnetic unbalance, and the amount of PM material used in the stationary part. Extensive finite element analysis (FEA) reveals the effectiveness of the proposed design. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a study of the structural and the magnetic correlation of the crystalline and amorphous phases in the nanocrystalline system Fe73.5Si13.5B9Nb3−x Mo x Cu1 (x=0, 1.5, 2, 3) was made. By means of Mössbauer spectroscopy, simple mass balance considerations and density measurements, both phases fractions and chemical compositions were calculated (in at%, wt% and vol%). Then, quasistatic magnetic measurements and ab initio calculations were used in a magnetic balance model in order to estimate the magnetic contribution of the remaining amorphous phase, which was compared to that of as-quenched amorphous samples of the same composition. The difference in both magnitudes showed the influence of penetrating fields and that these became more important for higher crystalline fractions. [ABSTRACT FROM AUTHOR]

This paper presents a pulse method for determination of resonance frequency of magnetoelastic sensors. The method eliminates the bias field that is necessary in previous methods and also allows fast and accurate detection. The stability tests of the system show an average standard deviation of 129 Hz and an average drift of -10.4 Hz/h. This system allows simultaneous detection of two sensors. A simulation of the operation of one and two sensors was shown to be very similar to the real data plots from the test system. Real tests have shown that adding a second sensor does not affect the resonance frequency of the first sensor. The effect of pulse magnetic field on the characteristics of the resonance signal, including resonance frequency, amplitude, and Q-value of frequency domain signal, has been studied and real time detection using magnetoelastic sensors was demonstrated in a flowing system. [ABSTRACT FROM AUTHOR]

Deposition by high power impulse magnetron sputtering (HIPIMS) is considered by some as the new paradigm of advanced sputtering technology, yet this is met with skepticism by others for the reported lower deposition rates, if compared to rates of more conventional sputtering of equal average power. In this contribution, the underlying physical reasons for the rate changes are discussed, including (i) ion return to the target and self-sputtering, (ii) the less-than-linear increase in the sputtering yield with increasing ion energy, (iii) yield changes due to the shift of species responsible for sputtering, (iv) changes due to greater film density, limited sticking, and self-sputtering on the substrate, (v) noticeable power losses in the switch module, (vi) changes in the magnetic balance and particle confinement of the magnetron due to self-fields at high current, and (vii) superposition of sputtering and sublimation/evaporation for selected materials. The situation is even more complicated for reactive systems where the target surface chemistry is a function of the reactive gas partial pressure and discharge conditions. While most of these factors imply a reduction in the normalized deposition rate, increased rates have been reported for certain conditions using hot targets and less poisoned targets. Finally, some points of economics and HIPIMS benefits are considered. [ABSTRACT FROM AUTHOR]

Abstract: Recent DIII-D experiments show that both magnetic balance and particle drifts are important to understanding how argon impurities accumulate in balanced and unbalanced double-null plasmas during ‘puff and pump’ radiating divertor operation. Unbalanced double-null shapes, which are biased in the direction opposite to the ion drift direction, have produced the best result to-date in terms of coupling a radiating divertor approach with an H-mode plasma. The proximity to balanced double-null that can be used for puff-and-pump may depend on the width of the heat flux profile in the scrape-off layer. A comparison of plasma behavior in the open lower divertor to that of the more closed upper divertor determined that plasma density control was far more sensitive to the ion drift direction than to the relative closure of the divertor. [Copyright &y& Elsevier]

Abstract: The relativistic four-component density functional approach based on the use of restricted magnetically balanced basis (mDKS-RMB), applied recently for calculations of NMR shielding, was extended for calculations of NMR indirect nuclear spin–spin coupling constants. The unperturbed equations are solved with the use of a restricted kinetically balanced basis set for the small component while to solve the second-order coupled perturbed DKS equations a restricted magnetically balanced basis set for the small component was applied. Benchmark relativistic calculations have been carried out for the X–H and H–H spin–spin coupling constants in the XH4 series (X=C, Si, Ge, Sn and Pb). The method provides an attractive alternative to existing approximate two-component methods with transformed Hamiltonians for relativistic calculations of spin–spin coupling constants of heavy-atom systems. In particular, no picture-change effects arise in our method for property calculations. [Copyright &y& Elsevier]

Abstract: Magnetic refrigeration employing magnetically ordered materials is a relatively novel technique, differing in some respects from magnetic cooling by means of adiabatic demagnetization of paramagnetic substances. Magnetic refrigeration has been known for more than a century and is based on the magnetocaloric effect. It has received new impetus recently because it has several advantages over vapor-compression refrigeration. In the last few years the magnetic and magnetocaloric properties of a large number of intermetallic compounds were investigated, in which the magnetic moments are carried by atoms of 3d transition elements. In the present paper we will focus on intermetallic compounds in which one of the components is Mn. The results obtained on several groups of such intermetallic compounds will be reviewed. By far the most promising materials of this group of intermetallics are compounds of the type MnFeP1−x As x . Although it is understood that these compounds are probably nontoxic, the presence of As atoms in them might form a mental barrier to exploit these materials on a commercial basis. Special attention will therefore be paid to efforts attempting to substitute other elements for As in MnFeP1−x As x with the proviso that the favorable magnetocaloric properties be retained. [Copyright &y& Elsevier]

Sensorless control of a permanent-magnet synchronous machine at low and zero speed is based on the injection of an oscillating high-frequency carrier signal. A particular demodulation technique serves to eliminate the estimation error introduced by pulsewidth modulation delay and the nonlinear characteristics of the inverter. Before the drive is started, the initial rotor position and the magnet polarity are detected. The initialization is performed by injecting an ac carrier and two short current pulses in a sequence. [ABSTRACT FROM AUTHOR]

We propose a discrete geometric formulation based on a magnetic scalar potential and on the circulation of an electric vector potential to solve eddy-current problems for nondestructive evaluation of steel bars with longitudinal defects. [ABSTRACT FROM AUTHOR]

Some technological and design peculiar properties have been discovered during working out design drawings and tooling for production of a short dipole model, which is being developed for synchrotron SIS 300, the FAIR project, GSI. These peculiarities should be taken into consideration during development of a full-scale prototype of the dipole. These features are related to both 2D and 3D geometries. This article presents some improvements that allow enhancing magnetic and mechanical characteristics, simplify processing complexity, and increase reliability and efficiency of the new design. Specifically, the field quality in the cross section is ameliorated. The length of the end parts is shortened, which gives larger effective length of the dipole. [ABSTRACT FROM AUTHOR]

The fully three-dimensional governing equations in the electron magnetohydrodynamic (EMHD) regime for a plasma with inhomogeneous density are obtained. These equations in the two-dimensional limit can be cast in terms of the evolution of two coupled scalar fields. The nonlinear simulations for the two-dimensional case are carried out to understand the propagation of EMHD magnetic structures in the presence of inhomogeneity. A novel effect related to the trapping of dipolar magnetic structures in the high density plasma region in the EMHD regime is observed. The interpretation of this phenomena as well as its relevance to the problem of hot spot generation in the context of fast ignition is presented. [ABSTRACT FROM AUTHOR]