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The authors investigate a semi‐flooded cooling technology for modular permanent magnet machines using flux gaps (FGs) in alternate stator teeth for extra cooling channels. The investigated machine is separated into stationary and rotational components by a polyether ether ketone sleeve. Liquid is directed into the stationary component to achieve a significant temperature reduction, at the same time, avoiding the liquid leakage into the rotating component that will cause an increase in friction losses. The FGs in the modular machine increase the contact area between coolant and machine components, resulting in better cooling efficiency. Furthermore, the FGs contribute to reduced pressure loss by minimising system flow resistance. The influence of the FG width on improving machine cooling efficiency, lowering machine temperature, and reducing pressure losses is delved. Additionally, the investigation considers the impact of inlet and outlet areas to reveal the influences stemming from fluid expansions and contractions in these regions. Computational fluid dynamics (CFD) modelling is employed to simulate the cooling performances of the investigated machines. In addition, the flow network analysis has also been employed to help understand the fluid behaviour within machines. A series of tests have been carried out to validate the CFD modelling. [ABSTRACT FROM AUTHOR]

Hybrid improper ferroelectricity (HIF) has been proposed as a candidate approach to create room- temperature multiferroic materials with an intrinsic electric-field controlled magnetism effect, and HIFs in bi-layered Ruddlesden-Popper Ca3-xSrxTi2O7 ceramics have been confirmed in the present work. The ferroelectric hysteresis loops are observed in these ceramics at room temperature, and the polar orthorhombic structures with oxygen octahedral rotation and tilt modes have been confirmed by room-temperature X-ray powder diffraction. The amplitudes of oxygen octahedral rotation and tilt modes decrease with the increasing x value, which in turn leads to the decrease of remnant polarization in these ceramics. A first-order phase transition has been evidenced by the differential scanning calorimetry measurement, and the temperature of phase transition decreases linearly with the increasing content of strontium cations. It is found that the amplitude of oxygen octahedral distortion is the dominating factor that affects ferroelectric polarization in partial-ordered bi-layered Ca3Ti2O7-based ceramics. [ABSTRACT FROM AUTHOR]

Surface mounted permanent magnet Vernier (SPM-V) machines, because of their high torque density and multi-pole structure, are promising candidates for low-speed direct-drive applications. To achieve high torque density, the SPM-V machines are generally designed with high gear ratios. Therefore, their operating frequencies can be much higher than those of the conventional SPM machines. This potentially increases the alternating current (AC) winding losses, especially those with form-wound coils proposed for high-power applications. This article investigates the AC losses (including skin effect, proximity effect, rotor PM induced, and circulating current losses) in form-wound stator coils of a 3 MW direct-drive SPM-V machine with different slot/pole number combinations. The study reveals that the SPM-V machines have significantly higher AC winding losses than their conventional SPM counterparts for similar operating conditions. To reduce the AC winding losses in SPM-V machines, a novel flux shunt concept is proposed along with other conventional techniques such as increasing the number of turns/coil (with terminal voltage being kept constant) and parallel strands/turn, providing extra clearance at slot opening. With the loss reduction techniques implemented, the SPM-V machines can achieve comparable efficiency but much higher torque density than their conventional counterparts. Moreover, the proposed flux shunt was also found to be very effective in reducing the potential risk of permanent magnet (PM) irreversible demagnetization, a key issue for SPM-V machines at high power ratings. [ABSTRACT FROM AUTHOR]

The structure and magnetic properties in doped Heusler alloys of Mn2CoGa and Mn2CoAl have been investigated by experiments and calculations. The main group elements of Ga or Al in the systems are substituted by the magnetic or non-magnetic transition metals, Co, Cu, V, and Ti. Three kinds of local ferromagnetic structures, Co-Mn-Co, Mn-Co-Mn, and Mn-Co-V, have been found. They embed in the native ferrimagnetic matrix and increase the magnetization with different increments. The Co-Mn-Co ferromagnetic structure shows the largest increment of 6.18μB/atom. In addition, interesting results for non-magnetic Cu increasing the magnetization and the V atom having a large ferromagnetic moment of about 1.0μB have been obtained. The exchange interaction energy can be increased by the newly added Co and depleted by supporting a ferromagnetic coupling in other substitution cases and showing the variation of the TC. Our calculation of electronic structure verifies the strong d-d hybridization when the three ferromagnetic structures are achieved. It has also been found that the covalent bonding from the Ga and Al determines the generation of the local ferromagnetic structure and the tolerance for dopant content. [ABSTRACT FROM AUTHOR]

The structure, magnetism, magnetic compensation behavior, exchange interaction, and electronic structures of Co50-xMn25Ga25+x and Co50-xMn25+xGa25 (x = 0-25) alloys have been systematically investigated by both experiments and first-principles calculations. We found that all the samples exhibited body centered cubic structures with high degree of atomic ordering. With increasing Ga content, the composition dependence of lattice parameter shows a kink point at the middle composition in Co50-xMn25Ga25+x alloys, which can be attributed to the enhanced covalent hybridization between the main-group Ga and the transition-metal atoms. Moreover, a complicated magnetic competition has been revealed in Co50-xMn25Ga25+x alloys, which causes the Curie temperature dramatically decrease and results in a magnetic moment compensation behavior. In Co50-xMn25+xGa25 alloys, however, with increasing Mn content, an additional ferrimagnetic configuration is established in the native ferromagnetic matrix, which causes the molecular moment monotonously decrease and the exchange interaction enhance gradually. The electronic structure calculations indicate that the Co50-xMn25+xGa25 alloys are likely to be in a coexistence state of the itinerant and localized magnetism. Our study will be helpful to understand the nature of magnetic ordering as well as to tune magnetic compensation and electronic properties of Heusler alloys. [ABSTRACT FROM AUTHOR]

The local structures and the g factors of two Cu2+ centers in YBa2Cu3O7–δ are theoretically studied by using the perturbation formulas of the g factors for a tetragonal and an orthorhombically elongated octahedral 3d9 clusters. The crystal-field parameters in these formulas are determined from the superposition model and the local distortions due to the Jahn–Teller effect. Based on the calculations, for the tetragonal Cu2+ center in YBa3Cu2O7, the Cu-O bonds are found to suffer the axial elongation of about 0.032 Å along the c-axis due to the Jahn–Teller effect. For the orthorhombic Cu2+ center in Y2BaCuO5, the Cu-O bonds is found to experience the axial elongation δZ (≈ 0.078 Å) along the c-axis and the planar bond length variation δX (≈ 0.012 Ǻ) in the perpendicular (ab) plane, responsible for the axial anisotropy Δg (= gz − (gx + gy)/2 = 0.168) and the perpendicular anisotropy δg (= gx – gy = 0.081). The theoretical g factors are in good agreement with the experimental data. The local structures of both Cu2+ centers are discussed. [ABSTRACT FROM AUTHOR]

This article investigates the impact of scaling on the electromagnetic performance of surface-mounted permanent-magnet Vernier (SPM-V) machines with a main focus on open-circuit induced Electro Motive Force (EMF). Three different power ratings, i.e., 3 kW, 500 kW, and 3 MW, have been chosen for this article. For each power rating, the SPM-V machines are analyzed for different slot/pole number combinations to compare their optimal performance with a conventional SPM machine. Step-by-step development of an analytical equation is presented for the prediction of induced EMF taking into account the interpole leakage of rotor permanent-magnets. 2-D finite-element analysis (FEA) has been used to validate the analytical equation across different power ratings. The analytical equation is thereafter utilized to study the influence of different geometric parameters on the performance of the SPM-V machines. It reveals that the back EMF and torque of SPM-V machines, for a given normalized pole pitch (rotor pole pitch to magnetic airgap length), are unaffected by the increase in airgap length due to scaling. However, the power factor of SPM-V, unlike the conventional SPM, reduces significantly with the increase in electrical loading due to the scaling effect. The analytical model for induced EMF and the 2-D FEA predicted results are validated by experiments using conventional SPM and SPM-V machine prototypes. [ABSTRACT FROM AUTHOR]

A total of three types of doubly salient synchronous reluctance machines have been comparatively studied to improve the torque performance using current harmonic injection methods. These machines are derived from the switched reluctance machines (SRMs) with different winding configurations, such as the double/single-layer mutually coupled SRMs (MCSRMs) and fully pitched SRMs (FPSRMs), by supplying them with sinewave current. Such current supply mode can lead to higher torque/power density and lower vibrations and acoustic noise compared with the conventional rectangular current supply. The proposed torque analytical model can predict the instantaneous torque of the doubly salient SRMs with sinewave current excitation and the current harmonics also can be selected in order to reduce the torque ripple and/or increase the average torque. It has been found that the third current harmonic injection shows the best performance for single-layer MCSRMs and FPSRMs because it improves the average torque and reduces the torque ripple at the same time. However, it has little influence on doubly-layer MCSRMs. To improve the torque performance of such machines, other harmonic currents, e.g., fifth and seventh, need to be used. Both static and dynamic tests have been carried out to validate the predictions. [ABSTRACT FROM AUTHOR]

This paper investigates the contribution of each order inductance harmonic to the torque (both average torque and torque ripple) of multiphase doubly salient synchronous reluctance machines (DS-SRMs). Such machines are similar to switched reluctance machines but supplied with sine wave currents. The investigations in this paper are as follows. First, a general analytical torque model based on Fourier series analysis of inductances has been built for machines with different phase numbers, slot/pole number combinations, and also winding configurations. The instantaneous torque for DS-SRMs with any given phase number can then be accurately predicted. Using such model, contribution of each order inductance harmonic to torque can be investigated separately. It is found that the torque ripple frequency of the DS-SRM only depends on phase number. For example, for an m-phase machine, there will be m $\times $ kth-order torque ripple if mod(mk, 2) = 0, where m is the phase number and k is a natural number. This paper also explains why certain phase numbers inherently produce lower torque ripple than others. The findings in this paper provide a future direction for potential torque ripple reduction methods either from machine design or advanced control. The simulations have been validated by experiments using a six-phase DS-SRMs. [ABSTRACT FROM AUTHOR]

Compared to nonmodular machines, modular topologies become increasingly attractive due to their simplified manufacture process, better fault-tolerant capability, and potentially reduced material consumption. In order to maintain or even enhance the machine performance while achieving high fault-tolerant capability, novel modular, single-layer winding switched reluctance machines (SRMs) with different pole numbers are proposed, which are supplied by rectangular wave current with different conduction angles. The influences of the pole number and flux gap width between E-core segmented stators on the electromagnetic performance have been investigated in terms of self- and mutual inductances, electromagnetic torque, copper loss, iron loss, and radial force. It has been found that the modular structures with higher rotor pole numbers than stator slot numbers (12-slot/14-pole and 12-slot/16-pole SRMs) can maintain and even improve the average torque due to the nature of self and mutual inductances. In addition, the torque ripples for modular machines are significantly reduced (below 50%), so do the iron loss and radial force, leading to higher efficiency albeit with potentially lower vibration and acoustic noise. Two prototypes with 12-slot/8-pole and 12-slot/14-pole combinations have been built with both nonmodular and modular structures to validate the predictions in terms of inductances and static torques. [ABSTRACT FROM AUTHOR]

This paper adopts simple analytical modeling to investigate the contribution of air-gap field harmonics to the torque production in some three-phase, 12-slot/8-pole doubly salient synchronous reluctance machines (DSRMs) with both conventional and mutually coupled winding configurations. The air-gap flux density has been calculated based on the analytically obtained magnetomotive force and doubly salient air-gap permeance for both the double-layer and single-layer DSRMs with different winding configurations. Then, the contribution of different air-gap field harmonics to average torque and torque ripple can be investigated and validated by direct finite-element analyses. It has been found that in the DSRMs, the 10th-order harmonic in the double-layer conventional winding (DLC), the 4th-order harmonic in the double-layer mutually coupled winding (DLMC), the 7th-order harmonic in the single-layer conventional winding (SLC), and the 10th-order harmonic in the single-layer mutually coupled winding (SLMC) have the highest contribution to positive average torque and with positive influence on torque ripple reduction. However, the 2nd-order harmonic in the DLC, the 8th-order harmonic in the DLMC, the 5th-order harmonic in the SLC, and the 2nd-order harmonic in the SLMC machines mainly reduce the average torque. [ABSTRACT FROM AUTHOR]

The flux gaps in alternate stator teeth of the modular permanent-magnet machines can have a significant impact on the total magnet flux density, and hence the potential magnet reversible/irreversible demagnetization under flux weakening operations or short-circuit conditions. Such a problem has not been studied in literature and will be investigated in this paper. The influence of flux gaps on the d-axis inductance and the potential peak short-circuit current is analyzed for different slot/pole number combinations. It is found that the flux gaps will affect both d-axis inductance and open-circuit flux linkage, and hence reduce short-circuit current of machines with pole number (2p) smaller than slot number (Ns), while they will increase the short-circuit current of machines with 2p > Ns . However, the opposite phenomena can be observed for demagnetization withstand capability. For machines having 2p < Ns, the flux gaps tend to lower withstand capability, while for machines having 2p > Ns, this capability can be improved. Other parameters such as magnet thickness and temperature have also been accounted for in the demagnetization analysis. Tests have been carried out to validate the predictions of inductances and short-circuit current, as well as performance such as phase back electromotive force, cogging torque, and static torque for machines with one defective magnet, which represents the case of partially demagnetized magnets. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of conduction angles on the performances of two 3-phase 12-slot/8-pole short-pitched switched reluctance machines (SRMs): single-layer SRM with conventional winding (SL-CSRM) and single-layer SRM with mutually coupled winding (SL-MCSRM). Both unipolar and bipolar excitations are employed for the SRMs with different conduction angles such as unipolar 120° elec., unipolar 180° elec., bipolar 180° elec., bipolar 240° elec., and bipolar 360° elec. Their flux distributions, self- and mutual-flux linkages, and inductances are analyzed, and followed by a performance comparison in terms of on-load torque, average torque, torque ripple, using 2-D finite-element method. Copper loss, iron loss, and machine efficiency have also been investigated with different phase currents and rotor speeds. The predicted results show that the conduction angle of unipolar 120° elec. is the best excitation approach for the SL-CSRM at low current and also modest speed, as its double-layer (DL) counterpart. However, at high current, the higher average torque is achieved by a conduction angle of unipolar 180° elec. For the SL-MCSRM, bipolar 180° elec. conduction is the most appropriate excitation method to generate a higher average torque but lower torque ripple than others. The lower iron loss is achieved by unipolar excitation, and the SL-CSRM with unipolar 120° elec. conduction produces the highest efficiency than others at 10 \textA\mathrm{ rms} . In addition, the performances of single-layer machines have been compared with those of the established DL-SRMs with conventional and mutually coupled windings. The prototype SRMs for both SL-CSRM and SL-MCSRM have been built and tested to validate the predictions. [ABSTRACT FROM AUTHOR]

This paper comprehensively investigates the electromagnetic performance of 3-phase, 12-slot, and 8-pole switched reluctance machines (SRMs) with different winding configurations, i.e., double/single layer, short pitched (concentrated), and fully pitched (distributed). These SRMs are supplied by sinewave currents so that a conventional three-phase converter can be employed, leading to behavior which is akin to that of synchronous reluctance-type machines. Comparisons in terms of static and dynamic performances such as d- and q-axis inductances, on-load torque, torque–speed curve, and efficiency map have been carried out using two-dimensional finite-element method (2-D FEM). It is demonstrated for the given size of machine considered that for same copper loss and without heavy magnetic saturation, both single- and double-layer mutually coupled SRMs (MCSRMs) can produce higher on-load torque compared to conventional SRMs (CSRMs). Additionally, double-layer MCSRM achieved the highest efficiency compared to other counterparts. When it comes to single-layer SRMs, they are more suitable for middle-speed applications and capable of producing higher average torque while lower torque ripple than their double-layer counterparts at low phase current. Two prototype SRMs, both single layer and double layer, are built to validate the predictions. [ABSTRACT FROM PUBLISHER]

This paper investigates the influence of mutual fluxes (inductances) on the resultant torque in three-phase conventional switched-reluctance machine (CSRM) and mutually coupled SRM (MCSRM) using the frozen permeability (FP) method. Under saturation conditions, the FP method allows accurately separating the torques due to self-flux and mutual flux, hence quantifying their contributions to torque generation. Then, appropriate current waveforms (unipolar or bipolar, square wave or sinewave) can be established to maximize the output torques. It is well known that the mutual torque of CSRM can be negligible. However, this paper has shown that when sinewave current is employed and under full or overload conditions, the torque will be significantly reduced due to non-negligible negative mutual torques. Different from CSRM, the self-torque and the mutual torque of MCSRM can be added if current waveform is properly chosen, e.g., sinewave currents. This can significantly boost the resultant torque. The predictions have been validated by experiments. [ABSTRACT FROM AUTHOR]

This paper proposes a novel cogging torque mitigation method for modular permanent magnet (PM) machines with flux gaps in alternate stator teeth. The slot openings (SOs) of the modular PM machines are divided into two groups in a special way. By shifting the SOs of two groups in opposite directions with the same angle, the machine cogging torque can be significantly reduced. An analytical formula of the desired shift angle is derived, and can be applicable to other modular machines with different slot/pole number combinations. Meanwhile, the influence of the proposed method on phase back electromotive force (EMF) is investigated, and the three-phaseback EMF waveforms remain balanced for all slot/pole number combinations after slot shifting. Experiments based on the existing prototypes are carried out to validate the finite-element modeling. [ABSTRACT FROM PUBLISHER]

This paper presents a simple analytical model for two types of three-phase surface-mounted permanent magnet machines: modular and unequal tooth (UNET) width machines with different slot/pole number combinations. It is based on the slotless open-circuit air-gap flux density and the slotted air-gap relative permeance calculations. This model allows calculating the opencircuit air-gap flux density, phase flux linkage, back electromotive force, and average torque of both the modular and UNET machines. Its accuracy has been validated by the 2-D finite-element (FE) method. A flux focusing/defocusing factor has also been introduced to analyze the influence of flux gaps in alternate stator teeth of modular machines on the machine electromagnetic performances. It has been found that by properly choosing the slot/pole number combination and flux gap width, the open-circuit air-gap flux density, the winding factor, and the flux focusing effect can all be improved. As a result, the performance of the modular machine can be significantly boosted. The analytical and FE models have been validated by experiments. [ABSTRACT FROM AUTHOR]

HLA-DRB1*11:143 has one nucleotide change from HLA-DRB1*11:01:01 where Aspartic Acid (70) is changed to Glycine. [ABSTRACT FROM AUTHOR]

This paper presents two short-circuit fault models of a hybrid excitation flux switching permanent magnet machine, i.e., excitation phase short-circuit and interturn short-circuit in excitation windings. Two-dimensional finite element (FE) method is used to calculate the major parameters, such as armature and excitation inductances, which are not only functions of rotor position, but also of armature and excitation currents. Moreover, in case of short-circuits, the variations of armature and excitation currents are often significant. This in turn leads to an important change in winding inductances. Therefore, in order to precisely predict machine performance under short-circuit conditions, the use of inductances versus rotor position and RMS currents is essential. With the obtained FE results, two MATLAB/Simulink-based models are established. Then, the previously mentioned short-circuits have been studied and their influences on electromagnetic performances, such as armature and excitation currents, speed and torque, armature and excitation copper losses, stator and rotor core iron losses, as well as permanent magnet (PM) eddy current losses are analyzed. Experiments have been carried out to validate the simulations. [ABSTRACT FROM PUBLISHER]

In order to simplify manufacture processes and improve fault-tolerant capabilities, modular electrical machines, especially the ones with segmented stators, are increasingly employed. However, flux gaps between segments are often inevitable. In this paper, to take advantage of these flux gaps to enhance the machine performance, novel modular permanent magnet machines with different slot/pole combinations have been proposed. The influence of these flux gaps on the electromagnetic performance of modular PM machines, such as winding factor, open-circuit air-gap flux densities, back-EMFs, cogging torque, on-load torque, inductances, magnetic saturation and copper losses, are comprehensively investigated and general rules have been established. It is found that for modular machines having slot number higher than pole number, the flux gaps between stator segments degrade the electromagnetic performance due to the lower winding factor and the flux defocusing effect. However, for modular machines having slot number lower than pole number, the electromagnetic performances can be significantly improved using proper flux gap width due to the higher winding factor and the flux focusing effect. The finite element results are validated by experiments using two prototype modular machines. [ABSTRACT FROM PUBLISHER]

The effect of TaOx capping layer on microstructures and magnetic properties of FePt thin films via annealing was studied. The structural ordering of FePt from face-centered cubic to face-centered tetragonal phases depends strongly on the oxygen contents in the capping TaOx layer. The role of the TaOx layer is used to separate the FePt grains, as revealed by TEM. The annealed FePt/TaOx (15%O2/Ar) exhibited the largest out-of-plane coercivity (Hc\sim 4.2 kOe) amongst all samples, compared to that (\sim2.4 kOe) in the reference FePt layer. At low oxygen content in FePt/TaOx bilayers, the Ta atoms may act as defects to obstruct the FePt ordering whereas at high oxygen contents, the excess oxygen atoms diffuse into the FePt layer and react with Fe to form iron oxides which give rise to the low coercivities, as characterized by the XPS depth profile and binding energy analysis. [ABSTRACT FROM AUTHOR]

The influence of covalent hybridization on the martensitic structure and magnetic properties of Ni50Mn5+xGa35-xCu10 shape-memory alloys has been investigated. It is found that the lattice distortion (c - a)/a of L10 martensite linearly increases upon substitution of Mn for Ga, showing a change of slope at Ga = 25 at. %, which is ascribed to a weakened covalent hybridization between main-group and transition-metal atoms. Moreover, due to the competition between the covalent hybridization and the magnetic ordering of the substituted Mn atoms, the magnetic moment per formula unit and the Curie temperature show maxima at Ga = 25 at. % as well. This behavior is closely associated with the corresponding changes of the strength of the covalent hybridization. The results, therefore, suggest that a careful control of the concentration of main-group atoms in Heusler alloys may serve as a tuning parameter for finding multifunctional materials. [ABSTRACT FROM AUTHOR]

This paper presents copper and iron loss models of a classical switched reluctance motor (SRM) and a mutually coupled switched reluctance motor (MCSRM). The iron losses in different parts of machines are then detailed. Based on the power losses model, a lumped parameter (LP) transient thermal model during driving cycles is performed, the analytical results are validated by the finite-element (FE) transient thermal model. Special attention has been paid to model the salient rotor and a method to transform the salient rotor into a nonsalient one has been proposed. A comparison between the maximum temperatures obtained by using different heat source (average power losses or instantaneous power losses during driving cycles) is given. The experimental tests are also realized to verify the analytical and numerical results. [ABSTRACT FROM PUBLISHER]

Noise problem limits the sensitivity of magnetic tunnel junction (MTJ) sensors for ultra-low magnetic field applications. Noise analysis not only helps in finding ways to eliminate noise disturbances but also essential for understanding the electronic and magnetic properties of MTJs. These approaches provide insight for optimizing the design of MTJ sensors before fabrication. This paper reviews the noise sources in MTJ sensors reported in recent years. Both the origins and mathematical derivations of the noise sources are presented, illustrating how different factors affecting the performance of MTJ sensors. A brief outlook of challenges in the future is also given. [ABSTRACT FROM AUTHOR]

Al2O3 magnetic tunneling junction (MTJ) sensors were fabricated with Conetic alloy Ni77Fe14Cu5Mo4 deposited as the free layer and pinned layer for its soft magnetic properties. It was observed that the Al2O3 MTJ sensors with Conetic exhibited relatively small easy-axis coercivity. Tunneling magnetoresistance (TMR) and noise measurements were carried out to characterize the sensors. TMR of 9.5% and Hooge parameter of 3.825 \times 10^-7\ \mum^2 were achieved without any hard-axis field. Hard-axis bias field was applied to eliminate the hysteresis and improve the linear field response of the MTJ sensor. The hysteresis was removed by applying an external magnetic field along the hard axis at 8 Oe and the sensor sensitivity was 0.4 %/Oe within a linear region at room temperature. The relationship between the Hooge parameter and hard-axis field was also investigated and the result demonstrated that the 1/f noise can be suppressed by an optimized hard-axis bias field. This work shows that it is feasible to use Conetic alloy as the soft magnetic layers in MTJ sensors for its small coercivity, and a hard-axis bias field can be used to linearize the sensor response and suppress the 1/f noise. [ABSTRACT FROM AUTHOR]

HLA‐A*11:120 has one nucleotide change from HLA‐A*11:01:01:01 where 295 T(ACC) is changed to S(AGC). [ABSTRACT FROM AUTHOR]

As gas turbines, wind farms, run-of-river hydro, photovoltaic and other renewable energy sources are becoming a growing component in the power system, the feasibility of applying the controllability of their expensive frequency-changers [based on voltage-source converters or (VSCs)] is examined to provide system damping. It is shown that irrespective of the location of the VSC-frequency changers along the transmission line, significant damping is available by the combined control of real and reactive power modulations. The finding is reached by eigenvalue analysis of the linearised equations and confirmed by digital simulation (PSCAD/EMTDC). Digital simulation is also applied to evaluate the size of injected complex power required for the best damping for a given converter rating. [ABSTRACT FROM AUTHOR]

By using laser-induced fluorescence to visualize liquid drops that are suddenly exposed to supersonic gas streams, we show that the previously available experimental results, which are based on the shadowgraph method, allowed misinterpretations that have lead to inappropriate conceptualizations (and theory) of the physics that govern breakup at high Weber numbers (We>103)—instead of the Rayleigh–Taylor piercing, the dominant mechanism is shear-induced motion with a significant radial component and instabilities on the so-generated, stretched liquid sheet. At low Weber numbers (We<102), the new data reveal the quantitative features of multiwave piercing by Rayleigh–Taylor instabilities. The highly resolved images provide uniquely suitable benchmarks for direct numerical simulations of interfacial instabilities in general and of drop breakup in particular. [ABSTRACT FROM AUTHOR]

A power injection control strategy is proposed for dynamic voltage restorers (DVR) under voltage sag or swell conditions. Under such a strategy, the error between the voltage of the energy storage capacitor in the DVR and a given reference voltage is extracted to control the injected power such that during an upstream voltage disturbance, zero or minimum power injection can be achieved automatically, while sudden phase jump of the load-side voltage can also be avoided. The proposed control strategy is analysed in detail and numerical examples are provided to demonstrate the effectiveness of the scheme. [ABSTRACT FROM AUTHOR]

Anisotropic superconducting properties in Sc5Ir4Si10 and Lu5Ir4Si10 single crystals are investigated. Both of these compounds are found to show quasi-one-dimensional superconductivity with better conduction along the c-axis and anisotropy parameter of about 2. Reflecting the partial destruction of the Fermi surface due to charge-density-wave formation, Lu5Ir4Si10 shows higher residual resistivity, lower superconducting transition temperature, and longer magnetic penetration depths compared with those of Sc5Ir4Si10. Similarity of superconducting properties including the anisotropy in Sc5Ir4Si10 and Lu5Ir4Si10 indicates that the absence of the charge-density wave in Sc5Ir4Si10 is controlled by a subtle difference in the Fermi surface topologies in these two compounds. [ABSTRACT FROM AUTHOR]

The paper presents a method of designing a class of robust H [sub ∞] generator excitation controller in a power system. The proposed controller is utilized to damp inter-area oscillations and enhance power system stability. The robust controller design procedure for a linear composite system is presented in terms of positive definite solutions to modified algebraic inequalities. The resulting controller guarantees closed-loop stability and an H [sub ∞]-norm bound on disturbance attenuation. The effectiveness of the H ∞ controller is demonstrated through digital simulation studies on a two-machine system. The digital simulation studies are conducted using a PSCAD/EMTDC software package. The simulation results show that the controller contributes significantly to the damping of inter-area oscillations and the enhancement of power system stability during disturbances. [ABSTRACT FROM AUTHOR]

HLA‐B*35:168 has one nucleotide change from HLA‐B*35:01:01:01 where 20 P is changed to R. [ABSTRACT FROM AUTHOR]

WC-TiC reinforced TiNi-Ti2Ni dual-phase intermetallic matrix coatings were labricated on the Ti6A14V substrate by laser alloying with 70 pure Ni and 30WC powders (wt.%) and then were dealt with by laser remelting. The effects of laser remelting on microstructure of the alloyed coatings were investigated by X-ray diffraction (XRD), optical microscopy (OM). scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS). In addition, mechanical properties were also evaluated. The results indicated that the remeltcd coating became denser with the reduction in defects compared with the alloyed coating. The average microhardness of the coating had few changes after remelting, however, the fracture toughness of the coating was increased significantly by 20% to 3.15 MPa-m1/2. Moreover, wear volume and mass loss of the coating before and alter laser remelting also showed that laser remelting contributed to the improvement in wear performance. [ABSTRACT FROM AUTHOR]

INTRODUCTION: The aim of this meta-analysis was to further explore whether the relapse, 5-year survival and metastasis the same or not between limb-salvage and amputation in the treatment of patients with limited stage EnnekingII pathologic fracture osteosarcoma. MATERIALS AND METHODS: An electronic search of the Medline, EMBASE and CNKI was done on October 2014. The clinical studies about amputation or limb-salvage surgery in the treatment of patients with limited stage EnnekingII pathologic fracture osteosarcoma were searched and reviewed. The effect size of relapse, 5-year survival and metastasis between the amputation and limb-salvage surgery were pooled by stata11.0 software (Stata Corporation, College Station, TX, USA, http://www.stata.com;) using random or fixed effect model. The funnel plot and Egger's line regression test were used for evaluation of publication bias. RESULTS: A total of 89 studies were identified and seven articles with 200 cases in the limb-salvage surgery group and 84 subjects in the amputation group were finally included in the meta-analysis. The pooled data indicated that no statistical different of risk for developing relapse between limb-salvage and amputation was found relative risk (RR) =1.40, 95% confidence interval (CI): 0.71-2.79, (P = 0.33). The 5-year survival rate of patients underwent limb-salvage surgery was smaller than patients received amputation RR = 1.86, 95%CI: 1.19-2.89, (P = 0.01); the metastasis rate of patients underwent limb-salvage surgery was significant decreased compared with patients received amputation RR = 0.56, 95% CI: 0.34-0.94, (P = 0.03). No publication bias was existed in this meta-analysis. CONCLUSION: Limb-salvage surgery does not increased the risk of relapse compared with amputation in the treatment of patients with limited stage EnnekingII pathologic fracture osteosarcoma. [ABSTRACT FROM AUTHOR]

INTRODUCTION: The aim of this meta-analysis was to further explore whether the relapse, 5-year survival and metastasis the same or not between limb-salvage and amputation in the treatment of patients with limited stage EnnekingⅡ pathologic fracture osteosarcoma. MATERIALS AND METHODS: An electronic search of the Medline, EMBASE and CNKI was done on October 2014. The clinical studies about amputation or limb-salvage surgery in the treatment of patients with limited stage EnnekingⅡ pathologic fracture osteosarcoma were searched and reviewed. The effect size of relapse, 5-year survival and metastasis between the amputation and limb-salvage surgery were pooled by stata11.0 software (Stata Corporation, College Station, TX, USA, http://www.stata.com;) using random or fixed effect model. The funnel plot and Egger's line regression test were used for evaluation of publication bias. RESULTS: A total of 89 studies were identified and seven articles with 200 cases in the limb-salvage surgery group and 84 subjects in the amputation group were finally included in the meta-analysis. The pooled data indicated that no statistical different of risk for developing relapse between limb-salvage and amputation was found relative risk (RR) =1.40, 95% confidence interval (CI): 0.71-2.79, (P = 0.33). The 5-year survival rate of patients underwent limb-salvage surgery was smaller than patients received amputation RR = 1.86, 95%CI: 1.19-2.89, (P = 0.01); the metastasis rate of patients underwent limb-salvage surgery was significant decreased compared with patients received amputation RR = 0.56, 95% CI: 0.34-0.94, (P = 0.03). No publication bias was existed in this meta-analysis. CONCLUSION: Limb-salvage surgery does not increased the risk of relapse compared with amputation in the treatment of patients with limited stage EnnekingⅡ pathologic fracture osteosarcoma. [ABSTRACT FROM AUTHOR]

Requirements like higher cleanliness and better quality of casting blooms are proposed for 350km/h higher speed rail steel. Present paper focuses on technical measures on improving the steel cleanliness and strand quality of 350km/h high-speed rail steel in Panzhihua Iron & Steel Group Company. By means of series of packaging technology like dephosphorization in BOF, ladle refining, mold electromagnetic stirring and dynamic soft reduction, dephosphorization rate cleanliness and morphology control are greatly improved, with [S]≤0.015%, [P]≤0.025%, [H]≤1.5 × 10, Al ≤ 0.004%, T[O] ≤20 × 10, the grade of central porosity and segregation ≤1.0, the grade of central crack and middle crack ≤0.5, index of central carbon segregation ≤1.05, severity level of type-A and type-B inclusions ≤2.0 and 1.0, respectively. The optimized process meets the technical requirements on producing 350 km/h high-speed rail steel and stable production is realized. [ABSTRACT FROM AUTHOR]

The in silico mapping (ISM) technique and its extension represent major advances for novel gene discovery in germplasm resources of inbred lines. However, the techniques suffer from a relatively high false-positive rate (FPR) and they do not consider the effect of linkage disequilibrium (LD) markers around the identified quantitative trait locus (QTL). In addition, it has not yet been established whether it is optimal to use absolute trait differences as the response variable. To address these problems, this article presents the multiple loci ISM (MLISM) approach, which uses all markers on the entire genome, along with a penalized maximum likelihood. The method proposed here was verified by a series of simulation experiments with a maize pedigree population of inbred lines of known ancestry. Results from the simulated studies show that the best response variable is the trait product. The MLISM FPR is substantially decreased and the proportion of the number of false QTL to the number of LD markers around the identified QTL is adequately reduced. The MLISM method, with the trait product as the response variable, is an improvement on the existing methods for novel QTL mapping in germplasm resources of inbred lines. [ABSTRACT FROM AUTHOR]

A novel circinal slot antenna with band-notched function suitable for UWB applications is presented and investigated in this paper. This antenna is designed to be used in frequency band of 3.1–10.6 GHz. Band-notched characteristic of antenna to reject the frequency band of 5.15–5.825 GHz, which is limited by IEEE 802.11a, is realized by parasitic inverted-U strip attached to the circinal slot plane. Experimental results show that the proposed antenna meets the requirement of wide-working bandwidth of 2.3–10.6 GHz with VSWR < 2, while avoiding the interference with the 5 GHz WLAN band. The parametric studies are performed numerically, and transfer functions of the antenna systems are given experimentally in this article. [ABSTRACT FROM AUTHOR]

A double-printed C-shape antenna for ultra-band application is proposed in this paper. With two C-shape dipole arms printed on the dielectric substrate and fed by a microstrip line, the antenna realized its ultra-wideband character by multistage impedance conversion. The impedance characteristic, radiation patterns and the transfer function are studied by both numerical simulation and experiment. The radiation patterns are approximately omni-directional with the VSWR < 2 from 3.1 to 10.6 GHz. Both transfer functions and group delay are smooth with linear phase which is valuable for the transmission of UWB signals. [ABSTRACT FROM AUTHOR]

Cold pilgering has been considered as the preferred rolling fabrication technology for difficult-to-deform tubular materials such as high-strength titanium alloy tubes. However, the tooling geometry may induce complex deformation and significantly influence crystallographic texture which is closely related to the dimension assuring and properties tailoring of tube products. In this study, taking high-strength Ti-3Al-2.5V tubes as the case material, the tooling design–related spatial deformation behaviors and crystallographic texture evolution of tube in cold pilgering are focused. A macro-meso scaled computation platform is established by combining the three-dimensional finite element (3D-FE) model with the viscoplastic self-consistent (VPSC) crystal plasticity model to predict both the inhomogeneous macrodeformation and microtexture evolution in cold pilgering. Two basic tooling parameters in pilgering, viz., E1 representing exponent of roller groove curve and mandrel curve and E2 representing exponent of groove clearance, are chosen as the design variables. The cold pilgering under different tooling parameters are simulated and analyzed. The results show that (1) The rolling force decreases with the increase of E1 , while the effect of E2 on the rolling force is not significant, and smaller E1 and larger E2 have advantage for preventing surface defects of the tube product; (2) The E1 of 2.8 and E2 of 2.0 are more conducive to the wall thinning–dominated deformation of tube; (3) Taking the contractile strain ratio (CSR) as an indicator for characterizing crystallographic texture–related mechanical properties, the appropriate values of E1 and E2 for desirable radial texture of tube product are obtained. [ABSTRACT FROM AUTHOR]

In order to maximise utilisation of nutrients for ruminants, researchers directed the supply of nitrogen and organic matter synchronously to the rumen. In the current research, two experiments were conducted, one using the in situ nylon bag technique and the other using in vivo study. In Experiment 1, dynamic degradation rates of organic matter (OM) and nitrogen of each feedstuff were determined using the in situ nylon bag technique. Accordingly, three diets were formulated with the same chemical components, but differing in synchrony index (0.74, 0.85 and 0.97). Experiment 2 was subsequently carried out in vivo to evaluate the influence of diet synchrony on rumen fermentation, productive performance, immunity status and endocrine in Chinese Holstein cows. Rumen degradability of OM and neutral detergent fibre (NDF) and total tract digestibility of OM were linearly increased with the increase of synchrony index, respectively (P < 0.05). Total volatile fatty acids concentration of rumen fluid was increased linearly with the increase of synchrony index (P < 0.05). Meanwhile, rumen ammonia nitrogen concentration and blood urea nitrogen concentration were decreased in cows with the increase of synchrony index, (P < 0.05). Microbial crude protein production, the efficiency of microbial protein synthesis, and milk protein percentage, were linearly increased with the increase of synchrony index (P < 0.05). Serum concentrations of prostaglandin E2 and immunoreactive fibronectin-γ were linearly decreased with the increase of diet synchrony index (P < 0.05). The aforementioned results implicate that an increase of diet synchrony index could improve diet's nitrogen utilisation, apparent digestibility of OM, and NDF. Additionally, it could promote rumen fermentation capacity, productive performance and immunity status in dairy cows. With the consideration of maximising nutrient utilisation, diet synchrony was investigated in the present research. Diets with a higher synchrony index improved nitrogen utilisation and digestibility of organic matter and neutral detergent fibre and cow productive performance and immunity status. The integration of synchrony index in a ration system would improve cow welfare and productive performance. [ABSTRACT FROM AUTHOR]

Review: 81 refs. [ABSTRACT FROM AUTHOR]

We report on unusual lattice parameter changes and tunable magnetic moment compensation in Mn50-xCo25Ga25+x (x = 0-25) Heusler alloys by substituting Ga for Mn. The observed lattice parameter first increases with increasing Ga content x, showing a maximum at x = 12.5, and then abnormally decreases due to the enhanced covalence effect between transition-metal and main-group atoms. Moreover, a tunable magnetic moment compensation was also observed due to the diversification in role of the main magnetic contributor when the structure varies from Hg2CuTi-type Mn2CoGa to Cu2MnAl-type CoMnGa2. These results provide an alternative way to simultaneously tune both the structural and magnetic properties of Heusler alloys, which is particularly important for developing flexible spintronics devices. [ABSTRACT FROM AUTHOR]

We have demonstrated the detection of alpha-fetoprotein (AFP) labeled with magnetic nanoparticles (MNPs) using MgO-based magnetic tunnel junction (MTJ) sensors. AFP is an important hepatic tumor biomarker and the detection of AFP has significant applications for clinical diagnostics and immunoassay for early-stage liver cancer indications. In this work, MgO-based MTJ sensors and 20-nm iron-oxide magnetic nanoparticles (MNPs) were used for detecting AFP antigens by a sandwich-assay configuration. The MTJ sensors with a sensing area of 4 × 2 μm2 possess tunneling magnetoresistance (TMR) of 122% and sensitivity of 0.95%/Oe at room temperature. The target AFP antigens of three concentrations were successfully detected, and the experimental data indicate that the resistance variations of the MTJ sensor increased with the AFP concentration ratios proportionally. These results demonstrate that MgO-based MTJ sensors together with MNPs are a promising biosensing platform for liver cancer immunoassay. [ABSTRACT FROM AUTHOR]

Silicon on insulator (SOI)-based transistors gated by nanogranular SiO2 proton conducting electrolytes were fabricated to mimic synapse behaviors. This SOI-based device has both top proton gate and bottom buried oxide gate. Electrical transfer properties of top proton gate show hysteresis curves different from those of bottom gate, and therefore, excitatory post-synaptic current and paired pulse facilitation (PPF) behavior of biological synapses are mimicked. Moreover, we noticed that PPF index can be effectively tuned by the spike interval applied on the top proton gate. Synaptic behaviors and functions, like short-term memory, and its properties are also experimentally demonstrated in our device. Such SOI-based electronic synapses are promising for building neuromorphic systems. [ABSTRACT FROM AUTHOR]

This paper proposes an analytical method that combines the superposition and the subdomain methods to predict the air-gap field distribution in permanent magnet (PM) machines with rotor eccentricity. The original machine with rotor eccentricity is divided into a number of air-gap sections along the circumferential direction. For each air-gap section, a concentric model is employed by adopting an equivalent air-gap length to predict the air-gap field using the subdomain method. The air-gap field distribution of the original model can then be synthesized from these concentric models. Consequently, the electromagnetic performance can be predicted accordingly, such as flux-linkage, back EMF, and so on. Finally, the direct finite element analysis is used to validate the efficacy of the proposed method. The proposed analytical method can be extended to other machines with different slot/pole number combinations and is particularly useful for analyzing the machines with large slot and pole numbers. [ABSTRACT FROM AUTHOR]

We demonstrated the detection of 20-nm iron–oxide magnetic nanoparticles (MNPs) using Al2O3 magnetic tunnel junction sensors (MTJs) with Conetic alloy. Conetic alloy Ni77Fe14Cu5Mo4 was deposited as the MTJ free layer and pinned layer due to its magnetically soft properties. The magnetoresistance (MR) curves of MTJs with Conetic alloy showed tunneling magnetoresistance of 8.0% with small hysteresis and high linearity in the sensing region, after applying an external magnetic field of 14 Oe along the hard axis. The sensitivity of the MTJ sensors with Conetic alloy was determined to be 0.3%/Oe within a linear region at room temperature. The MNPs of three different concentrations were successfully detected by the shifts of the MR loops of the MTJs, and it was observed that the resistance deviations of the MTJ sensors increased with the logarithm of MNP concentrations. The maximum resistance deviation was 0.16 \Omega for an MNP concentration of 20.0 mg/mL. MTJ sensors, together with MNPs, are a promising platform for future biosensor applications, and this paper shows that Conetic alloy is feasible for improving the performance of this platform. [ABSTRACT FROM AUTHOR]

Commutation failure, which is a very frequent dynamic event in HVDC inverters, can deteriorate the availability of HVDC links and thus affect the performance of the power system. Most commutation failures are caused by voltage reduction due to ac system faults. In this paper, efforts are made to lower the effect of commutation failure on the power system, and the remedy is implemented in a fuzzy controller. In order to achieve control flexibility, the output of the fuzzy controller is made appropriate by setting a self-adjusting proportional factor. The validity and effectiveness of the fuzzy controller is verified by simulation which shows that the fuzzy controller can decrease commutation failure frequency induced by ac system faults. [ABSTRACT FROM AUTHOR]

An epidemiological method, field-tested in Hunan, China, to identify residents potentially susceptible or insusceptible to endemic schistosomiasis japonica is described, as a prelude to selection of subjects for immunogenetic studies. After an initial cross-sectional survey on two islands (Qingshan and Niangashanpopulation 2990) in 1995-1996, an informative cohort (N = 249) was selected for treatment and 9-month follow-up to measure exposure and re-infection. Both the population prevalence (15.8%) and the geometric mean intensity of infection (26.2 eggs/g faeces) indicated that the islands were moderately endemic for schistosomiasis. Exposure measurements revealed a strong, positive, linear association (r = 0.70) between daily activity diaries and direct water-contact observation. Individuals identified as stool-positive for schistosomiasis had significantly more water contact than those who were egg-negative (P = 0.03). Almost all (93%) of the cohort had ultrasonographic evidence of periportal fibrosis before treatment but in only 1.2% was this fibrosis scored 1 in terms of the stages identified by the World Health Organization. At the follow-up it was possible to classify the 249 subjects into three, distinct, exposure-infection epidemiological groups. The first group (N = 20) was susceptible to re-infection and constituted 8% of the cohort. The second group (N = 61) was apparently insusceptible to re-infection despite the continuing high levels of exposure and included 24% of the cohort. The other 68% of the cohort (N = 168) remained uninfected but were at most only moderately exposed, or had a status indeterminate due to non-compliance. This epidemiological identification of susceptibles and insusceptibles for schistosomiasis japonica links field and ongoing laboratory studies aimed at characterising the genetic and immunological factors associated with resistance to re-infection and/or disease. [ABSTRACT FROM AUTHOR]