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The solar wind protons undergo significant perpendicular heating when they propagate in the interplanetary space. Stochastic heating and cyclotron resonance heating due to kinetic Alfvén waves (KAWs) are two proposed mechanisms. Which mechanism accounts for the perpendicular heating is still an open question. This paper performs tests for the two mechanisms based on Wind observations during 2004 June and 2019 May. Results show that heating rates in terms of stochastic heating theory considerably depend on the parameter of plasma β. For the solar wind with moderately high β, the theoretical heating rates are comparable to or larger than empirical heating rates, suggesting that the stochastic heating could be a powerful mechanism. For the solar wind with low β, on the contrary, the majority of data have theoretical heating rates much lower than empirical heating rates, showing that the stochastic heating seems to be weak in this case. On the other hand, it is found that, when the propagation angles of KAWs are around 70°, theoretically predicted damping wavenumbers of KAWs are equal to the observed wavenumbers at which magnetic energy spectra become significantly steep. This may imply that resonance heating due to cyclotron damping of KAWs could be another mechanism if KAWs have propagation angles around 70°.

Patients with implanted orthopaedic devices represent a growing number of subjects undergoing magnetic resonance imaging (MRI) scans each year. MRI safety labelling is required for all implants under the EU Medical Device Regulations to ensure regulatory compliance, with each device assessed through standardised testing procedures. In this paper, we employ parametric studies to assess a range of clinically relevant factors that cause tissue heating, performing simulations with both radiofrequency (RF) and gradient coil (GC) switching fields, the latter of which is often overlooked in the literature. A series of ‘worst-case’ scenarios for both types of excitation field is discussed. In the case of GC fields, large volume implants and large plate areas with the field orientated perpendicular to the plane cause the highest heating levels, along with sequences with high rates of field switching. Implant heating from RF fields is driven primarily from the ‘antenna effect’, with thin, linear implants of resonant length resulting in the highest temperature rises. In this work, we show that simplifications may be made to the field sequence and in some cases the device geometry without significantly compromising the accuracy of the simulation results, enabling the possibility for generic estimates of the implant heating for orthopaedic device manufacturers and opportunities to simplify the safety compliance process.

This work presents results of investigation of crossed-field demagnetization in 2G high temperature superconducting stacks at temperatures in the range of 77 - 20 K and in a variable frequency, corresponding to the particular rotor application. We propose a method to reduce the demagnetization rate for a given stack configuration necessary for the superconducting rotor operating at a cryogenic temperature. This technique involves 3-D wrapping the stack of tapes with perpendicular layers of similar superconducting properties. Previous ‘proof of concept’ studies documented some improvements in flux demagnetisation reduction for basic configuration. In the present study a more advanced approach based on magnetic flux shielding is adopted. The presented results provide an important contribution to development for design solutions that aim to increase the operational time before remagnetisation of the stacks would be required.

A magnetic skyrmion is stabilized via the Dzyaloshinskii–Moriya interaction in a perpendicularly magnetized thin nanowire. When the skyrmion is driven by a spin-transfer torque due to spin currents flowing through the wire, the skyrmion approaches the wire edge owing to the skyrmion Hall effect. In other words, the skyrmion moves obliquely along the longitudinal direction of the wire. The skyrmion often breaks or disappears because of this oblique motion. In this study, we propose an elliptical skyrmion to prevent this disappearance. We simulated the current-induced motion of an elliptical skyrmion produced in a wire through a micromagnetic approach. The elliptical skyrmion was also moved obliquely to the longitudinal direction of the wire. When a small current flowed through the wire, the skyrmion moved in the longitudinal direction of the wire after it approached the wire edge. When a larger current flowed through the wire, the skyrmion disappeared after it approached the wire edge. The elliptical skyrmion can be driven over a long distance with a larger current compared to a circular skyrmion. The motion of the skyrmion approaching the wire edge was analyzed using Thiele’s equation, with an external force. We estimated the external force from the simulation results of the skyrmion motion. The external force was proportional to the distance between the skyrmion edge and the wire edge. The results of this study indicate that using the elliptical skyrmion as a binary digit in a magnetic memory, such as a skyrmion-based racetrack memory, can be advantageous in term of the stability of the binary digit.

Interlayer exchange-coupled synthetic antiferromagnets (SAFs) have the combined advantages of both high frequency of antiferromagnets and easy detection of ferromagnets. Here, magnetic excitations are investigated by theoretical analysis and micromagnetic simulations in SAFs that consist of two identical ferromagnetic layers with perpendicular magnetic anisotropy. Different from the common in-phase acoustic mode and out-of-phase optic mode, linearly or circularly polarized spin wave modes can be excited at zero bias field by using different types of microwave magnetic fields. Once a bias magnetic field is applied along the easy-axis, left-handed (LH) and right-handed (RH) polarization modes are observed, and the resonance frequency of RH (LH) mode of the SAFs increases (decreases) linearly with the increase of bias magnetic fields until a critical spin-flop field is reached, which is in accordance with collinear antiferromagnets with easy-axis anisotropy. These simulation results agree with the theoretical derivation and provide fundamental insight into the nature of dynamic properties of the perpendicularly magnetized SAFs, which may provide new prospects for spintronic applications.

The mathematical model of the working fluid movement in the flow section of the wedge type two-disc parallel gate valve is developed. The simulation of the fluid flow through the valve cavity is carried out, as a result the flow parameters are obtained in a wide range of Reynolds numbers at the entrance to the calculated area. The dependence of the hydraulic resistance as a function of the Reynolds number for liquid and gas flow is calculated. The various positions of the shut-off body in the flow part of the valve are considered and the area of reduced pressures in which the effect of cavitation may occur during fluid flow is estimated.

A new method for designing stellarators with variable-thickness perpendicular permanent magnets has been developed, based on a two-step magnet design strategy that we previously proposed for designing stellarators with standardized magnet blocks. Our design strategy uses a ‘local compensation’ method to obtain an initial magnet design and a ‘global fine-tuning’ method to further optimize the initial design. The new method is compared to the previously proposed Fourier decomposition method, and the results indicate that this new method can yield a similar magnet design for an N fp = 2 quasi-axisymmetric stellarator at a lower computational cost. High accuracy is achieved, as demonstrated by a normal magnetic field square on the plasma surface of χ B 2 = 3.43 × 1 0 − 8 T 2 m 2 , a maximum residual of B n = 3.44 G s for a ∼1 T total field, and a flux-surface-averaged residual B n of B n / B = 3.16 × 1 0 − 5 relative to the total field. Furthermore, the new method can automatically yield a magnet design with large areas of continuous vacancies for ports and plasma access, which is more flexible than the Fourier decomposition method. These results indicate that the new method is robust and effective when used to design stellarators with variable-thickness perpendicular permanent magnets, and, most importantly, that the two-step magnet design strategy has great potential to develop permanent magnet design methods suitable for various magnet layouts.

In the application of additive manufacturing, it is inevitable to use some formed parts with a smaller height. The analysis of various mechanical properties of these formed parts is the focus of research. In this paper, the fatigue performance of a titanium alloy specimen with a 10 mm height and electron beam selective melting is studied. By analyzing the structure and phase of the overall fatigue specimen, and then cutting the overall specimen parallel and perpendicular to the additive manufacturing direction, the tensile and fatigue tests in different directions are performed to detect the fatigue cracks at the fracture propagation the way to research. It is found that there are two ways of secondary crack propagation between fatigue bands, and three cracks are generated during the fatigue secondary crack propagation.

We consider flow of a thin film on an incline with negatively buoyant particles. We derive a one-dimensional lubrication model, including the effect of surface tension, which is a nontrivial extension of a previous model (Murisic et al 2013 J. Fluid Mech. 717 203–31). We show that the surface tension, in the form of high order derivatives, not only regularizes the previous model as a high order diffusion, but also modifies the fluxes. As a result, it leads to a different stratification in the particle concentration along the direction perpendicular to the motion of the fluid mixture. The resulting equations are of mixed hyperbolic-parabolic type and different from the well-known lubrication theory for a clear fluid or fluid with surfactant. To study the system numerically, we formulate a semi-implicit scheme that is able to preserve the particle maximum packing fraction. We show extensive numerical results for this model including a qualitative comparison with two-dimensional laboratory experiments.

Instability of faults and weak joints of rock mass is affected by underground three-dimensional loading conditions as well as hydrostatical fluid pressure within pores and cracks. This paper presents a direct shear testing method to characterize the shear behavior of Kimachi sandstones under various pore pressures and joint roughnesses. The direct shear test was conducted under three mutually perpendicular loads and with various levels of pore pressure through effective utilization of a true triaxial loading system. An overview of the experimental method, its advantages, and results showing the usefulness of the experiment were presented. Sample permeability in the direction parallel to the joint was measured during the shear test.

Increasing the data storage in next-generation hard disk drives requires a reduction in the physical dimensions of read sensors. Tunneling magnetoresistance heads yield high magnetoresistance (MR) ratio but with a high resistance-area product (RA) that is suboptimal for devices. Giant magnetoresistance (GMR) head using different materials is an alternative way to improve reader performance with high MR ratio and low RA. In this paper, we theoretically study the effect of material properties and the layer thickness on RA and MR ratio in a trilayer system via an atomistic model combined with the spin transport model. The GMR stack can be constructed by the atomistic model and the RA and MR ratio can be directly calculated by considering the spin accumulation and spin current from the spin transport model. It is found that the spin valve using the (Figure presented) Heusler alloy electrode with high spin polarization exhibits a high MR ratio and RA of 64 (Figure presented) which is better than the spin valves using conventional ferromagnets such as Co, NiFe and CoFe. Moreover, we consider the thickness dependence of the change of RA ((Figure presented)). Increasing the free layer thickness yields the increase in (Figure presented) and MR ratio because of the enhancement of the bulk spin scattering. Additionally, the results show that the (Figure presented) depends on the spin diffusion length of the nonmagnetic materials ((Figure presented)). The (Figure presented) increases from 3 up to 10 (Figure presented) when (Figure presented) increases from 35 to 1200 nm. This investigation shows the possibility for read head design of HDDs with areal density beyond 2 Tb in-2.

A numerical study reports that the zero-field skyrmions in FeGe thin films are stabilized when a FeGe layer is exchange coupled to a single-domain Ni layer, which has been magnetized perpendicularly. Due to the small thickness, an easy-plane anisotropy in the FeGe layer is taken into account, and the skyrmion-crystal state is favored to appear for low anisotropies and intermediate FeGe/Ni interlayer exchange couplings, and finally transformed from a labyrinth-like and into an out-of-plane uniform state for the large couplings or into an in-plane state for the high anisotropies. Furthermore, the maximum skyrmion charge number is bigger for the periodic and fixed boundary conditions with an out-of-plane magnetization; on the contrary, the Bloch-type skyrmions can be frozen and stabilized for the larger couplings on the fixed boundary with an in-plane magnetization, similar to the experimental results of the magnetic-field-induced skyrmions. Finally, the skyrmion charge number and diameter both decrease if the nonmagnetic defects exist, and the skyrmion centers are prone to being captured by defect sites. This work evidences that the ensembles of homochiral skyrmions stabilized in the multilayers fabricated by well-established technologies present a roadmap to design new classes of the materials that can host skyrmions.

By driving hot electrons between two metal plates connected by a wire loop, high power lasers can generate multi-tesla, quasi-static magnetic fields in miniature coil targets. Many experiments involving laser-coil targets rely on proton deflectometry directed perpendicular to the coil axis to extract a measurement of the magnetic field. In this paper, we show that quantitative measurements using perpendicular probing are complicated by the presence of GV m−1 electric fields in the target that develop on sub-ns timescales. Probing parallel to the coil axis with fiducial grids is shown to reliably separate the electric and magnetic field measurements, giving current estimates of I ≈ 5 kA in 1 mm- and 2 mm-diameter wire loops. An analytic model of proton deflection in electric and magnetic fields is used to benchmark results from the particle-in-cell code and help deconvolve the magnetic and electric field deflections. Results are used to motivate a new experimental scheme that combines a single-plate target with axial proton probing and direct current measurements. This scheme has several important advantages over the traditional target and diagnostic set-up, enabling the robust measurement of coil magnetic fields and plasma properties, as well as making it easier to validate different theoretical models at a range of laser intensities.

In-plane magnetization on the surface of three-dimensional topological insulators (3D TIs) tunes the Dirac cone's location in thek-space. We theoretically show that a normal/ferromagnetic junction on the surface of 3D TIs bends the propagation direction of Dirac fermions when the magnetization has a component perpendicular to the junction. This effect leads to a Hall conductance, which flows parallel to the interface. Also, it creates an indirect gap that manifests itself in the longitudinal conductance of the junction. The sign of Hall conductance is related to the in-plane magnetization direction. Based on this effect, we propose a set up to detect it experimentally. Moreover, this bending effect imposes a torque on the junction calledcurrent transfer torque(CTT). We show thez-component of CTT is non-zero in the presence of bending effect. Also, its value and direction that can be used in fabricating new devices are related to the Hall conductance.

The stability of the ion-temperature gradient mode in quasisymmetric stellarators is assessed. This is performed using a set of analytical estimates together with linear gyrokinetic simulations. The peak growth rates, their corresponding real frequencies and wave-vectors are identified. A comparison is made between a first-order near-axis expansion model and eleven realistic designs obtained using numerical optimization methods. It is found that while the near-axis expansion is able to replicate the growth rates, real frequencies and perpendicular wave-vector at the inner core (both using simplified dispersion relations and first-principle gyrokinetic simulations), it leads to an overestimation of the growth rate at larger radii. An approximate analytic solution of the ITG dispersion relation for the non-resonant limit suggests growth rates could be systematically higher in quasi-axisymmetric (QA) configurations compared to quasi-helically (QH) symmetric ones. However except for very close to the axis, linear gyrokinetic simulations do not show systematic differences between QA and QH configurations.

The paper considers various semi-empirical methods of the linear coefficient of thermal expansion (CTE), a, calculation. Debye-Grüneisen model was used as a basis and adjusted by taking account of thermodynamic (molar heat capacity, enthalpy) and elastic (Young, bulk, and shear moduli, Poison ratio) characteristics of metals. The formulas for numerical calculations of CTE are derived using: (1) elastic longitudinal modulus, (2) microscopic constants, and (3) enthalpy. CTE were calculated for 25 metals, Ge and Si, and five hexagonal single-crystals in directions perpendicular and parallel to the principle crystallographic axis. Theoretical values of a show good agreement with the experimental ones.

Publisher Copyright: © Max-Planck-Institut fuer Plasmaphysik. A desirable scenario for future fusion devices is one in which dissipative processes in the scrape-off layer (SOL) are maximized, aiming to detach the divertor plasma. The access to such a regime in current devices is thought to be correlated to the increase of the perpendicular particle transport in the SOL. In this work we investigated numerically how increasing perpendicular transport globally affects the SOL plasma through the SOLPS-ITER code package. For this we modelled one L-mode discharge, performed at the ASDEX Upgrade tokamak, trying to obtain the most accurate fit to the experimental data at the outer midplane. Studying the plasma solutions and analyzing the resulting momentum and power balances in the SOL allowed to characterize how enhancing perpendicular SOL transport leads to the experimentally observed phenomena, i.e. the formation of a density shoulder at the midplane and the partial detachment of the divertor plasma. The results suggest that strong momentum losses caused by the increase of transport are able to explain the qualitatively observed detachment in the modelled discharge. The concurrent enhanced ionization of neutrals resulting from divertor recycling, triggered by an increase of radial energy transport in the SOL, can be invoked as a cause for the shoulder formation.

In many high-temperature superconducting (HTS) applications, HTS coated conductors carry DC currents under external AC magnetic fields. There are two AC loss mechanisms in this situation: magnetization loss due to the external magnetic field and dynamic loss due to the interaction between the DC current and the external magnetic field. The sum of these two loss components is referred to as total loss. In this work, the total loss in a 4 mm wide REBCO coated conductor is measured under perpendicular AC magnetic fields up to 105 mT at 77 K, 70 K, and 65 K, with reduced DC current level, i (I dc/I c0), from 0.025 to 0.98, where I dc is the transport DC current value and I c0 is the self-field critical current of the coated conductor at each temperature. The experimental results show a good quantitative agreement with an analytical equation for each loss component, as well as 2D finite element modelling (FEM) results from H -formulation. For any given temperature, we observe that the total loss is mostly dominated by magnetization loss at i< 0.2, while dynamic loss makes a comparable, even greater contribution to total loss at i > 0.5. Electromagnetic analysis from the FEM modelling shows the evolution process of total loss, where the dynamic loss region and magnetization loss region vary across the conductor width at high magnetic fields or high DC current level. The simulation results also reveal the superposition of (positive) DC current and the anti-parallel (negative) shielding current, which occurs at high DC current level. The superposition drives the current density of one conductor edge to subcritical stage, and it leads to one-sided loss generation in each half-cycle. Our results provide a valuable reference for total loss behaviours in REBCO coated conductors.

Magnetic tunneling junctions with strong perpendicular shape anisotropy attract attention due to their high-density magnetic random access memory. As thermal stability increases, the power consumption also increases. To solve this problem, devices are made to be driven by spin–orbit torque (SOT) instead of spin-transfer torque. However, the assisting field needed for deterministic switching is a major obstacle for SOT devices. In this work, we demonstrate an L-shaped electrode structure attached to the magnetic recording layer to induce a composite SOT, achieving high-speed and field-free magnetization switching. Meanwhile, a comparative study between L-shaped and sidewall electrode structure demonstrates that the L-shaped structure leads to fast and low-power switching. Finally, the switching characteristic at various current densities and spin Hall angles is studied and it turns out that to achieve high-speed reversal, the current density and the spin Hall angle need to be optimized, which might be attributed to strong in-plane effective field component disturbance. The novel L-shaped structure is feasible for high-speed, low-power and deterministic switching and has great potential in spintronic applications.

Strained materials can exhibit drastically modified physical properties in comparison to their fully relaxed analogues. We report on the x-ray absorption spectra (XAS) and magnetic circular dichroism (XMCD) of a strained NiFe2O4 inverse spinel film grown on a symmetry matched single crystal MgGa2O4 substrate. The Ni XAS spectra exhibit a sizable difference in the white line intensity for measurements with the x-ray electric field parallel to the film plane (normal incidence) vs when the electric field is at an angle (off-normal). A considerable difference is also observed in the Fe L 2,3 XMCD spectrum. Modeling of the XAS and XMCD spectra indicate that the modified energy ordering of the cation 3d states in the strained film leads to a preferential filling of 3d states with out-of-plane character. In addition, the results point to the utility of x-ray spectroscopy in identifying orbital populations even with elliptically polarized x-rays.

We present a scheme that enables the observation of interference effects in the resonance fluorescence of a V-type atom with orthogonal dipole moments. Specifically, we consider the atomic configuration of a J g = 0 to J e = 1 transition driven by a single laser field. By employing polarization-sensitive detection in such a way that the light emitted on the two transitions become indistinguishable, we show that one can simulate the effect of vacuum-induced coherence on the resonance fluorescence of this system. In addition, we demonstrate the possibility of realizing atomic transitions with both parallel and antiparallel dipole moments and their effects on the fluorescence spectrum. The interference induced leads to interesting features in the fluorescence spectrum such as asymmetric spectral peaks, enhancement and suppression of the sidebands, and disappearance of fluorescence in the particular direction of detection. The numerical results are understood in the context of the dressed states of the combined atom–field system.

We investigate the tagged-particle motion in a strongly interacting quasi-confined liquid using periodic boundary conditions along the confining direction. Within a mode-coupling theory of the glass transition we calculate the self-nonergodicity parameters and the self-intermediate scattering function and compare them with event-driven molecular dynamics simulations. We observe non-monotonic behavior for the in-plane mean-square displacement and further correlation functions which refer to higher mode indices encoding information about the perpendicular motion. The in-plane velocity-autocorrelation function reveals persistent anti-correlations with a negative algebraic power-law decay t −2 at all packing fractions.

A duct flow generated by a planar jet at the inlet and affected by a magnetic field perpendicular to the jet's plane is analyzed in high-resolution numerical simulations. The case of very high Reynolds and Hartmann numbers is considered. It is found that the flow structure is drastically modified in the inlet area. It becomes determined by three new planar jets oriented along the magnetic field lines: two near the walls and one in the middle of the duct. The downstream evolution of the flow includes the Kelvin-Helmholtz instability of the jets and slow decay of the resulting quasi-two-dimensional turbulence.

Short cracks tend to develop at high and irregular rates compared to macroscopic cracks, making the prediction of fatigue life a challenging task. In this work, a numerical framework combining crystal plasticity model and the Extended Finite Element Method (XFEM) is applied to study the slip-controlled short crack growth in a polycrystal superalloy RR1000. The model is calibrated from experiments and used to evaluate short crack growth paths and rates. Two fracture criteria are used and compared: the onset of fracture is controlled by the total and individual cumulative shear strain respectively, and the crack grows either perpendicular to the direction of maximum principal strain or along crystallographic directions.

In this study, the three-dimensional time-dependent Ginzburg-Landau equations were numerically solved to visualize the motion of the flux lines in a superconductor under a transverse magnetic field. Pins were inserted into a superconducting rectangular parallelepiped, and the magnetic field dependence of the normalized critical current density Jc was calculated. Anisotropy yZ of different magnitudes was introduced along the direction of the magnetic field (z-axis). Different pin shapes and orientations were also considered: columnar pins aligned parallel to the direction of either the magnetic field or the current flow, spherical pins, and a planar pin in the field-current plane. For the columnar pins aligned parallel to the field (along the flux lines), J c showed almost no dependence on yZ. Additionally, a peak in the Jc -B c urve for this pin geometry was observed at normalized magnetic field, B= 0.4 for all considered yz. In contrast, J c was dependent on yZ for the columnar pins aligned parallel to the current flow (perpendicular to the flux lines) and the spherical pins. At low magnetic fields (B= 0.1), J c increased with increasing yZ in both these cases. In the case of the planar pin, J c showed no dependence on yZ. In conclusion, when a pin was inserted parallel to the normalized magnetic field B, Jc did not decrease even when the z-axis anisotropy yZ was large.

We investigate properties of perpendicular anisotropy magnetic tunnel junctions (pMTJs) with a stack structure MgO/CoFeB/Ta/CoFeB/MgO as the free layer (or recording layer), and obtain the necessary device parameters from the tunneling magnetoresistance (TMR) vs. field loops and current-driven magnetization switching experiments. Based on the experimental results and device parameters, we further estimate current-driven switching performance of pMTJ including switching time and power, and their dependence on perpendicular magnetic anisotropy and damping constant of the free layer by SPICE-based circuit simulations. Our results show that the pMTJ cells exhibit a less than 1 ns switching time and write energies < 1.4 pJ; meanwhile the lower perpendicular magnetic anisotropy (PMA) and damping constant can further reduce the switching time at the studied range of damping constant α < 0.1. Additionally, our results demonstrate that the pMTJs with the thermal stability factor ≃ 73 can be easily transformed into spin-torque nano-oscillators from magnetic memory as microwave sources or detectors for telecommunication devices.

Single-atom magnets represent the ultimate limit of magnetic data storage. The identification of substrates that anchor atom-sized magnets firmly and, thus, prevent their diffusion and large magnetic anisotropy has been at the centre of intense research efforts for a long time. Using density functional theory we show the binding of transition metal (TM) atoms in defect sites in the graphene lattice: single vacancy and double vacancy, both pristine and decorated by pyridinic nitrogen atoms, are energetically more favourable than away from the centre of defects, which could be used for engineering the position of TMs with atomic precision. Relativistic calculations revealed magnetic anisotropy energy (MAE) of ∼10 meV for Ir@NSV with an easy axis parallel to the graphene plane. MAE can be remarkably boosted to 50 meV for OsIr@NSV with the easy axis perpendicular to the graphene plane, which paves the way to the storage density of ∼490 Tb/inch2 with the blocking temperature of 14 K assuming the relaxation time of 10 years. Magnetic anisotropy is discussed based on the relativistic electronic structures. The influence of an orbital-dependent on-site Coulomb repulsion U and a non-local correlation functional optB86b-vdW on MAE is also discussed.

Magneto-plasmonic phenomena on CoPt/ZnO/Ag stacked nanolayers were investigated in polar Kerr excitation geometry. The nanolayer displays an ideal square-shaped out-of-plane magnetic hysteresis loop with a large polar Kerr activity. The surface plasmon resonances (SPRs) induce drastic magneto-optical (MO) responses with a narrow linewidth and a sharp reversal of the Kerr polarity. The CoPt/ZnO/Ag nanolayer is a candidate for high-performance chemical sensor elements. For example, an MO‒SPR sensor with a Pd surface layer was applied for hydrogen detection. The Pd layer acts as a transducer for both hydrogen detection and plasmon response. Substantial MO responses to the exposure of hydrogen gas can be observed. The results show that the polarized sensing signal is not affected by the intensity of the incident light. The use of the new type of MO‒SPR element with polar Kerr activity leads to a stable chemical sensing system with a simple measurement configuration.

The proposed design of the glass cleaning robot has two columns, each of whose ends are connected to four vacuum suction cups. Vacuum ducts connect the suction cups to the vacuum pump. Solenoid valves are used for controlling the suction in the suction cups so that the effective movement of the legs can be achieved. The vacuum supply to the two suction cups at the end of one column is cut off for moving the robot. Now, the pneumatic piston is used to move that column while keeping the other column fixed. This helps in the vertical motion of the robot. Similarly, another set of columns connected to a pneumatic piston is fixed perpendicular to the vertical column, which enables the robot to move in a horizontal direction. A cleaning unit is attached to the robot for the desired cleaning purpose. It consists of a microfiber brush, which continually cleans the surface as the robot moves with the help of a DC motor. A CAD model was designed and a static stress analysis while the robot is fixed on the surface was done using Autodesk® Fusion™ 360. The movement of the robot on vertical as well as on inclined surface is simulated. The results of the analysis show that the robot can successfully hold on to the wall with four suction cups and is able to climb vertical surfaces with more ease than inclined surfaces.

Basements and foundations are designed following the current regulatory documents. In the case of a faulty design, even a flawlessly executed structure will no longer meet the operational requirements. Global construction experience shows that most of the accidents in constructed structures are caused by errors made during the construction of foundations. This paper describes the methodology for calculating single-row foundations for loads acting in a plane perpendicular to the row plane. In each specific case, a large number of alternative decisions can be made by the designer. The calculation of foundations using this technique will ensure the reliability and quality of the design and construction of buildings and structures.

Atom-scaled ripple structure can be intrinsically formed because of thermal instability or induced stress in graphene or two-dimensional (2D) materials. However, it is difficult to estimate the period, amplitude, and shape of such a ripple structure. In this study, by applying the geometrical phase analysis method to atomically resolved transmission electron microscopy images, we demonstrate that the atom-scaled ripple structure of MoS2 nanosheet can be quantitatively analyzed at the subnanometer scale. Furthermore, by analyzing the observed ripple structure of the MoS2 nanosheet, we established that it is inclined by approximately 7.1° from the plane perpendicular to the incident electron beam; it had 5.5 and 0.3 nm in period and amplitude, respectively. For quantitative estimation of ripple structure, our results provide an effective method that contributes to a better understanding of 2D materials in the sub-nanometre scale.

We use density function theory to study the carrier distribution in bilayer graphene under a perpendicular electric field. The carrier distribution in bilayer graphene strongly depends on the interlayer stacking arrangements, field strength, and carrier concentration. Unusual carrier localization, which is dependent on the stacking arrangement, is observed under a high electric field and low carrier doping concentration. For all other field and carrier doping concentration conditions, the carriers are distributed throughout the layers, irrespective of the interlayer stacking arrangements.

The development of instruments for measuring the electric field strength is not a simple scientific and practical task. First of all, this is due to the high metrological requirements that are imposed on sensors of electric field strength. There is a wide variety of electric field sensors of various shapes (cubic, cylindrical, spherical), the principle of action (directional and non-directional reception) and design features (housing, uncased) do not provide the desired metrological characteristics. Therefore, scientific work related to the development of sensors of electric field strength is developing and relevant. The aim of the scientific research is to create a frameless three-axis electric field strength sensor, which would be easy to calculate both for housing sensors, as well as simplicity of design and small mass as for frameless sensors. The constructive sensor created as a result of scientific research represents three mutually perpendicular square dielectric plates. The sensing element bases are square conductive sensing elements. The sensor has a different spatial measurement range and depends on the desired error. A large error correlates with a wider range. For a measurement error of no more than 10%, the maximum possible spatial measurement range will be a = 0.33. Consequently, the minimum possible distance to the field source, at which the sensor error is no more than 10%, will be d = 3L, where L is half the side of the square sensitive element.

This work will investigate the effect of the circular cylinders distance variation perpendicular the free stream installed in front of the returning to increase the turbine performance. Computational Fluid Dynamics using Gambit 2.2.30 software and ANSYS 17.0 software has been used to solve the incompressible URANS. Numerical model is validated towards experimental data at TSR 1.078. The working fluid is in verification using air at Reynolds of 4.32 x105. The ds/D is 0.5 at gap (S/D) of 0.95 with varying stagger angle of 0°, 30°, 60° and 90° with TSR of 0.3, 0.5, 0.7, 0.9, 1.1 and 1.3. The change of the stagger angle increase the turbine performance at a stagger angle of 60° followed by the increase of pressure in front side and reduce of the back of blade. In addition, stagger angle of 0° influences a circular cylinder become blockage and decrease the performance.

Domain-wall motion type magnetic memories are expected to be among the next generation of magnetic recording devices and vertical-NAND memories. In particular, three-dimensional race track memory (3D-RM), which extends vertically from a substrate is important for high integration. We propose a vertical 3D-RM loop consisting of two horizontal and two vertical nanowires in which the magnetic anisotropy is perpendicular to the substrate. The horizontal nanowires contain perpendicularly magnetized domains and Néel type domain walls (DWs). The vertical nanowires contain longitudinally magnetized domains with head-to-head or tail-to-tail DWs. DW motion is demonstrated using micromagnetic simulations based on the Landau–Lifshitz–Gilbert equation. We find that a DW can pass around a corner while deforming its own shape. The threshold current density to push a DW around a corner has a maximum value for wire thickness of about 10 nm.

Tectonic stress is an important factor influencing the development of joints. The tectonic stress in Jijicao is preliminary analyzed based on joints measurement, structural features tracing and stereographic projection. It is considered that the NW and NE trending tectonic systems in the study area belong to the products of different tectonic processes in different times. After intrusion, Jijicao granite rock mass has been forced in normal fault type stress, and the NW steeply dipping joints under vertical maximum principal stress and horizontal minimum principal stress squeezing on NE generated. Thereafter, the in-plate action is adjusted, and the minimum principal stress is deflected from NE to NW, resulting in a steep inclined joint system with the maximum principal stress nearly perpendicular and the minimum principal stress being subjected to NW horizontal extrusion.

Ultrasound waves propagating in water or soft biological tissue are strongly reflected when encountering the skull, which limits the use of ultrasound-based techniques in transcranial imaging and therapeutic applications. Current knowledge on the acoustic properties of the cranial bone is restricted to far-field observations, leaving its near-field properties unexplored. We report on the existence of skull-guided acoustic waves, which was herein confirmed by near-field measurements of optoacoustically-induced responses in ex-vivo murine skulls immersed in water. Dispersion of the guided waves was found to reasonably agree with the prediction of a multilayered flat plate model. It is generally anticipated that our findings may facilitate and broaden the application of ultrasound-mediated techniques in brain diagnostics and therapy., Comment: 7 pages, 5 figures, appendix with 2 figures

A real-time interlock system for power injection in electron cyclotron resonance heating (ECRH) was developed to be applied to Large Helical Device (LHD) plasma. This system enabled perpendicular injection, thus improving the performance of ECRH more than has ever been achieved before in LHD. Perpendicular propagation of the electron cyclotron wave at 77 GHz became more insensitive to the effect of refraction in comparison to the conventional oblique propagation. The achieved central electron temperature in the case of perpendicular injection was approximately 2 keV higher than that in the case of standard oblique injection for a central electron density of 1 × 1019 m−3 by 1 MW injection. With such improved performance of ECRH, high-density ECRH plasma of 8 × 1019 m−3 was successfully sustained after the injection of multiple hydrogen ice pellets for the first time in LHD.

Magnetic field correction factors are needed for absolute dosimetry in magnetic resonance (MR)-linacs. Currently experimental data for magnetic field correction factors, especially for small volume ionization chambers, are largely lacking. The purpose of this work is to establish, independent methods for the experimental determination of magnetic field correction factors k B ⃗ , Q in an orientation in which the ionization chamber is parallel to the magnetic field. The aim is to confirm previous experiments on the determination of Farmer type ionization chamber correction factors and to gather information about the usability of small-volume ionization chambers for absolute dosimetry in MR-linacs. The first approach to determine k B ⃗ , Q is based on a cross-calibration of measurements using a conventional linac with an electromagnet and an MR-linac. The absolute influence of the magnetic field in perpendicular orientation is quantified with the help of the conventional linac and the electromagnet. The correction factors for the parallel orientation are then derived by combining these measurements with relative measurements in the MR-linac. The second technique utilizes alanine electron paramagnetic resonance dosimetry. The alanine system as well as several ionization chambers were directly calibrated with the German primary standard for absorbed dose to water. Magnetic field correction factors for the ionization chambers were determined by a cross-calibration with the alanine in an MR-linac. Important quantities like k B ⃗ , Q for Farmer type ionization chambers in parallel orientation and the change of the dose to water due the magnetic field c B ⃗ have been confirmed. In addition, magnetic field correction factors have been determined for small volume ionization chambers in parallel orientation. The electromagnet-based measurements of k B ⃗ , Q for 7 MV / 1.5 T MR-linacs and parallel ionization chamber orientations resulted in 0.9926(22), 0.9935(31) and 0.9841(27) for the PTW 30013, the PTW 31010 and the PTW 31021, respectively. The measurements based on the second technique resulted in values for k B ⃗ , Q of 0.9901(72), 0.9955(72), and 0.9885(71). Both methods show excellent accuracy and reproducibility and are therefore suitable for the determination of magnetic field correction factors. Small-volume ionization chambers showed a variation in the resulting values for k B ⃗ , Q and should be cross-calibrated instead of using tabulated values for correction factors.

We study the spin conductivity of the bulk states of three-dimensional topological insulators within Kubo formalism. Spin Hall effect is the generation of the spin current that is perpendicular to the applied voltage. In the case of a three-dimensional topological insulator, applied voltage along $x$ direction generates transverse spin currents along $y$ and $z$ directions with comparable values. We found that a finite non-universal value of the spin conductivity exists in the gapped region due to the inversion of bands. Contribution to the spin conductivity from the vertex corrections enhances the spin conductivity from the filled states. These findings explain the large spin conductivity that has been observed in topological insulators., 8 pages, 8 figures

In MRgRT, dosimetry measurements are performed in the presence of magnetic fields. For high-resolution measurements, small-cavity ionization chambers are required. While Monte Carlo simulations are essential to determine dosimetry correction factors, models of small-chambers require careful validation with experimental measurements. The aim of this study is to characterize small-cavity chamber response coupled to magnetic fields. Small-cavity chambers (PTW31010, PTW31016, PTW31021 and PTW3022) are irradiated by a 6 MV photon beam for 9 magnetic field strengths between -1.5 T and +1.5 T. The chamber axis is orientated either parallel or perpendicular to the irradiation beam, with the magnetic field always perpendicular to the beam. MC simulations are performed in EGSnrc. The sensitive volume of the chambers is reduced to account for the inefficiency adjacent to the guard electrode (dead volume) based on COMSOL calculations of electric potentials. The magnetic field affects the chamber response by up to 4.1% and 4.5% in the parallel and perpendicular orientations, respectively, compared to no magnetic field. The maximal difference in dose response between experiments and simulations is up to 6.1% and 4.5% for parallel and perpendicular orientation, respectively. When the dead volume is removed, which accounts for the 15%-23% of the nominal volume, the difference, in most cases, is within the stated uncertainties. Nevertheless, for a particular chamber, the reduced nominal volume barely improved the agreement between the experimental and calculated relative response (4.53% to 4.13%). This disagreement may be due to the imperfect chamber geometry model, as was found from microCT images. A detailed uncertainty analysis is presented. The characterization of small-cavity ion chamber response coupled to magnetic fields is complex. Small differences between real and model chamber geometry that normally would be insignificant become an issue in the presence of magnetic fields. Accurate characterization of the nominal volume is essential for small-cavity ion chamber modelling.

We investigate properties of a particle confined to a hard-wall spiral-shaped region. As a case study we analyze in detail the Archimedean spiral for which the spectrum above the continuum threshold is absolutely continuous away from the thresholds. The subtle difference between the radial and perpendicular width implies, however, that in contrast to the ‘less curved’ waveguides, the discrete spectrum is empty in this case. We also discuss modifications such as multi-arm Archimedean spirals and spiral waveguides with a central cavity; in the latter case bound state already exist if the cavity radius exceeds a critical size. For more general spiral regions the spectral nature depends on whether they are ‘expanding’ or ‘shrinking’. The most interesting situation occurs in the asymptotically Archimedean case where the existence of bound states depends on the direction from which the asymptotical value of width is reached.

The problem of an inclined impact by an elastic plate on a thin liquid layer is considered. Evolution of the flow behind the plate is studied. The main input parameters are the position of the separation point of the liquid from the plate and the speed of the liquid under this point. The flow in the wake behind the plate is described by shallow water equations without gravity. Analytical formulae for the shape of the free surface behind the plate are derived. The study is focused on the possibility of the formation of jets arising from the wake perpendicular to the liquid layer. The problem is solved in two stages: before and after the formation of the first such a jet. The effects of the flow speed at the beginning of the wake, its time derivative, and the law of motion of the separation point on the formation of jets are investigated. The positions of the jets, their speeds and shapes are determined. Using the obtained results, mechanisms of the thin layer aeration behind the plate are discussed.