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Radiofrequency (RF) coils are employed to transmit and/or receive signals in Magnetic Resonance (MR) systems. The design of home-made, organ-specific RF coils with optimized homogeneity and/or Signal-to-Noise Ratio (SNR) can be a plus in many research projects. The first step requires accurate inductance calculation, this depending on the conductor's geometry, to later define the tuning capacitor necessary to obtain the desired resonance frequency. To fulfil such a need it is very useful to perform a priori inductance estimation rather than relying on the time-consuming trial-and-error approach. This paper describes and compares two different procedures for coil inductance estimation to allow for a fast coil-prototyping process. The first method, based on calculations in the quasi-static approximation, permits an investigation on how the cross-sectional geometry of the RF coil conductors affects the total inductance and can be easily computed for a wide variety of coil geometries. The second approach uses a numerical full-wave method based on the Finite-Difference Time-Domain (FDTD) algorithm, and permits the simulation of RF coils with any complex geometry, including the case of multi-element phased array. Comparison with workbench measurements validates both the analytical and numerical results for RF coils operating within a wide field range (0.18–7 T). [ABSTRACT FROM AUTHOR]

Abstract A new semi‐analytical expression is presented based on two integrations for calculating the magnetic force of a solenoid inductor wound by rectangular cross‐section wire. The authors simplified the solenoid inductor coil to a collection of circular coils, and the current density of the coils in the radial direction which was inversely proportional to its radius is considered. The obtained expressions can be implemented by adaptive Gaussian quadrature integration with MATLAB programming. In addition, they used the filament method and the finite element method to calculate the magnetic force on the solenoid inductor coil. The correctness of the semi‐analytical expressions was verified by comparing the results of the semi‐analytical numerical method with those of the filament method and the finite element method, respectively. The derived semi‐analytical expressions of magnetic force allow a low computational time compared with the filament method and the finite element method to a specific accuracy. The calculation results show that: the solenoid inductor coil tends to compress in the axial direction, and the axial magnetic force on the outermost coils is the largest; the solenoid inductor coil tends to expand outward in the radial direction, and the radial magnetic force on the intermediate coil is the largest.

This paper presents a non-intrusive solenoid valve fault diagnosis method, which adopts the eigenvalue extraction scheme and combines the time-frequency analysis and time-domain analysis of the current signal through the solenoid valve fault pattern recognition method. Specifically, the research group selected the solenoid valve driving end current value and its second-order change rate curve as the characteristic curve, and then it extracted the time-domain parameters and the corresponding frequency band energy of the second-order change rate as the characteristic value. Then, the research group conducted time-frequency analysis on the basis of the current signal, created a multi-feature fusion feature vector and then input it into a multi-class support vector machine (SVM) for solenoid valve fault diagnosis. To evaluate the method, the research group developed a working solenoid valve model that integrated a magnetic circuit, circuit and spool motion, and the research group examined four typical solenoid valve states (normal, spring broken, spool stuck and spool slightly stuck), for which the research group collected the current signals during solenoid valve energization and closing. The trials involved analyzing the current characteristics of the drive end, both in simulation and experimental setups, and the research group demonstrated that the proposed drive end current detection diagnosis method can improve the accuracy of recognition by 15.22% compared with traditional neural network recognition methods. The SVM strategy exploiting a multi-feature fusion strategy can improve recognition accuracy by 8.7% and verification accuracy by 42.11% compared with SVM on the basis of the energy feature values. [ABSTRACT FROM AUTHOR]

Energy and temporal radiation characteristics of the pulsed inductive CO2 gas laser with RF excitation as the function of RF pump-pulse duration τ with xenon additions to a gas mixture of the laser have been experimentally investigated. This made it possible to develop an efficient pulsed inductive CO2 laser with an output energy E > 1.2 J (the efficiency η ~ 17%), using a He:N2:CO2:Xe gas mixture [the (Xe) = 4%]. In this case, the lasing pulse duration tpuls (a full width at half-maximum) was 3.5 ms at a τ = 10 ms. For the pulsed inductive CO2 laser with RF excitation, it was shown for the first time a xenon addition to a gas mixture made it possible to achieve an efficiency η ~ 27% at the output energy E more 600 mJ. Pulses of RF current propagated along the solenoid, and the inductive discharge was formed to create population inversion by IR transitions of CO2 molecules. [ABSTRACT FROM AUTHOR]

As part of the European Strategy for Particle Physics there is an ongoing development towards a Future Circular Collider (FCC-ee) where electron-positron collisions could be used to study the entire electro-weak sector in a low background environment. Particle detectors are used to study these collisions and a strong magnetic field is required to measure the particles’ momenta. Currently, two detector concepts are being studied: the Innovative Detector for Electron-positron Accelerators (IDEA) and the CLIC-Like Detector (CLD). Both these detectors include a superconducting solenoid magnet with a central field of $2 \,\mathrm{T}$ of which the designs are presented here. The IDEA magnet has an stored magnetic energy density of 14 kJ/kg and in CLD this is 12 kJ/kg. Taking into account their respective free-bore diameters of $4.2 \,\mathrm{m}$ for IDEA and $7.2 \,\mathrm{m}$ for CLD this results in very challenging designs for which the mechanical and quench studies are presented. Their results are promising, but extensive R&D on these magnets would be needed in the future to reach the goals set out in the Conceptual Design Report (CDR). [ABSTRACT FROM AUTHOR]

The ITER Central Solenoid (CS) consists of a stack of six independent coil packs called modules. It features a total height of 18 m and a diameter of over 4 m. The modules are in an advanced stage of fabrication and testing by the US ITER Project Office (USIPO) and its subcontractor General Atomics (GA). A qualification module mockup at one to one scale but of reduced height was wound and Vacuum Pressure Impregnated (VPI) by GA to validate final manufacturing, using tooling and processes fully representative of a series module. The module was submitted to a thermal cycle down to the temperature of 4.5 K at which the coils will be cooled by supercritical helium. During plasma operation, the CS modules are subjected to a complex combination of static and dynamic forces. The understanding of the mechanical behaviour of the CS module coils is of paramount importance to analyse and predict the overall response of the CS stack. To this purpose, an extensive programme of investigation of the module mockup has been defined and applied. This allowed assessing, through examination and testing of a large number of VPI conductor array samples extracted from the mockup, the soundness of the coil through advanced non-destructive examination techniques including X-ray microtomography, dimensional metrology measurements and micro-optical observations. Moreover, additional testing of physical and mechanical properties carried out at room and cryogenic temperature allowed the behaviour of the conductor stacks to be assessed. The paper summarises the results of these investigations and their interpretation through mechanical analyses based on the individual properties of the coil constituents. [ABSTRACT FROM AUTHOR]

The electron cooling technology is applied in the spectrometer ring (SRing) to improve the luminosity of ion beam for the High Intensity heavy-ion Accelerator Facility (HIAF). The electron cooler consists of a gun section, two 90-degree toroids, a cooling section and a collector section. There are four kinds of main coils used to provide longitudinal magnetic fields along the path of the electron beam. In this paper, we present the modeling and analyzing of the electron cooler magnets by three-dimension software. The optimizing of the magnetic field of cooling section is completed to achieve the required effective cooling length. The magnetic fields along the electron beam path and ion beam path are calculated and the beam trajectory of typical ion is also simulated to offer data for correcting the orbit. [ABSTRACT FROM AUTHOR]

A time-of-flight polarized neutron imaging setup was realized by integrating an in situ pumped polarized 3He spin filter and energy dispersive neutron camera on the neutron technique development beamline (BL-20) of the China Spallation Neutron Source (CSNS). Test experiments were performed with a solenoid with aluminum wire as a sample. These demonstrated that polarized radiography with a field of view in diameter 2.0 cm at different wavelengths can be obtained. The wavelength-dependent polarization was used to distinguish the neutron polarization behavior for different positions inside and outside the solenoid. The results of this work show the possibility of applying the technique at CSNS and marks a milestone for future polarized neutron imaging developments. [ABSTRACT FROM AUTHOR]

ND-GAr is one of three detector systems in the design of the DUNE Near Detector complex, which will be located on the Fermilab campus, sixty meters underground and 570 m from the source of an intense neutrino beam. ND-GAr will consist of a cylindrical 10-bar gaseous Argon Time Projection Chamber (TPC) and a surrounding sampling electromagnetic calorimeter embedded within a superconducting solenoid, the cryostat and yoke for which together serve as the pressure vessel. While various options for the specific configuration of ND-GAr are being explored, essential design work for the detector has moved forward in recent months. This document describes basic mechanical, electrostatic, and gas flow design features of the ND-GAr TPC and presents results of electrostatic simulations of the interior of the pressure vessel for both single and dual-anode arrangements. Simulations are implemented with the Elmer finite-element software suite and related programs. [ABSTRACT FROM AUTHOR]

In this paper, a non-linear model of a 2–2 way, on–off fast-switching valve is used. The model includes subsystems of electrical, magnetic, mechanical and fluid. Pulse width modulation (PWM) technique is adopted to energise the on–off solenoid valve and allow the air to flow towards the actuator. Since the non-linear behaviour of valve is of great importance, to reduce the delay in performance of switching valves, different approaches are proposed. Furthermore, hysteresis, proportional integrator (PI), optimal model predictive and fuzzy logic controller (FLC) are used and compared. Also, to improve the valve behaviour, an empirical setup based on AVR microcontroller with FLC is implemented. Empirical and simulation results indicate that all proposed control methods have superior performance. However, the fuzzy method is easy to implement in practice. [ABSTRACT FROM AUTHOR]

The electrohydraulic valve system can realize continuous variable valve timing and lift using the flexibility of liquid. However, the existing electrohydraulic valve systems usually rely on a high-speed solenoid valve to control the on and off states of the hydraulic circuit, which pushes up the system cost. This paper introduces a continuous hydraulic variable valve timing and lift system with adjustable volume (CVVTL). Unlike the other electrohydraulic valve systems, the CVVTL does not need a high-frequency servo valve to control each valve but adjusts the valve timing and lift by controlling the system volume. However, the maximum operating speed of hydraulic variable valve systems is limited by the inherent pressure fluctuation. To relax the limit, the authors further studied the pressure fluctuation features of the CVVTL system under various conditions and summarized the harms of the fluctuation. After identifying the causes of pressure fluctuation of the CVVTL system, the authors came up with systematic countermeasures to system pressure fluctuation. [ABSTRACT FROM AUTHOR]

In this study, we designed a new type of digital hydraulic transformer using four gear–pump/motor units with a displacement ratio of 20:21:22:23 and two control valve groups that consist of four solenoid directional valves. The driving gear shafts of the four gear–pump/motor units are fixedly connected to achieve synchronous rotation. The two control valve groups are respectively installed through an integrated valve block on the inlet and outlet of each gear–pump/motor unit. With the objective of reducing the installed power and energy consumption of hydraulic traction systems, we propose a new energy-saving hydraulic system based on a digital hydraulic transformer. This hydraulic system uses a digital hydraulic transformer as a pressure/flow control element. By controlling the power on/off states of eight solenoid directional valves, the digital hydraulic transformer can realize a change in output flow and then a change in speed of the hydraulic cylinder piston rod. Through the theoretical derivation and simulation analysis of the hydraulic system pressure/flow change process, and the experimental verification of the built hydraulic traction system based on the experimental platform, a conclusion is drawn that the proposed digital hydraulic transformer can change the output pressure/flow of a hydraulic system through a binary digital control, verifying the feasibility of the pressure change principle of the designed digital hydraulic transformer and the rationality of the hydraulic traction system circuit. [ABSTRACT FROM AUTHOR]

A two-dimensional Wigner cluster (2DWC) with the number of electrons up to 200 in a parabolic potential well has been studied numerically and analytically. It has been shown that the inner part of the 2DWC in the axisymmetric potential well is polycrystalline, whereas electrons in outer layers form pronounced circular shells. The scaling of the cluster under the variation of the stiffness of the potential well has been considered. The threshold of the free rotation of the solid cluster in the axisymmetric potential well has been determined. The action of an alternating magnetic field generated by a coaxial solenoid on the 2DWC has been examined. It has been shown that the initially immobile solid 2DWC subjected to a weak vortex electric field begins to rotate at an angular velocity equal to half the cyclotron frequency. Furthermore, in a stronger vortex field, the cluster not only rotates but also begins to be periodically compressed, holding its structure. A further increase in the vortex field can lead to the total collapse of the cluster accompanied by the destruction of its structure. A sufficiently strong vortex electric field can also result in the differential rotation of the shells of the 2DWC. The rotational friction coefficient caused by ohmic losses in the gate, which can restrict the free rotation of the 2DWC, has been determined. [ABSTRACT FROM AUTHOR]

Characteristics of annular electron flow formed in electron gun with a multitip field emitter were determined experimentally and by numerical simulations, and the possibility to achieve electron beam current up to 75 mA was demonstrated. The gun performance was stable in technical vacuum conditions—at the pressure of ~10−7 torr. Electron velocity distributions in a flow on transverse and longitudinal components were determined. It was shown that the relative root-mean-square transverse velocity spread varied with radial coordinate within the annular beam wall from ca. 6% to 30%, while the total spread in the electron flow was about 60%. [ABSTRACT FROM AUTHOR]

A model-based study is conducted to develop a high-performance solenoid gas Injector applied for compressed natural gas (CNG) fueled engines. Operation of the solenoid gas Injector is described through mathematical models, Including mechanical and electrical models. The solenoid of the gas injector is modeled in Maxwell software to simulate its electromagnetic force in static mode, which is based on specifications of a real solenoid gas injector. The electromagnetic force along with flux obtained by the solenoid model in Maxwell is then imported into AMESim software to simulate the operating characteristics of the solenoid gas injector in transient mode, such as motion characteristics of the plunger, response time, and injection quantity. The electromagnetic force and operating characteristics of the solenoid gas injector are investigated under the effects of structural parameters, including core and sleeve shapes. The simulation results show that the electromagnetic force and open response time of the solenoid gas injector are significantly improved by changing the core and sleeve shapes. [ABSTRACT FROM AUTHOR]

The holding force acting on a levitated object during near-field acoustic levitation has not been statically and directly measured so far. In this study, it was considered to realize such a measurement when a levitated object has a large displacement from the vibration source. In previous studies, under restricted conditions, the holding force has been calculated indirectly by image processing or measured from the balance with gravity by tilting the apparatus. In this article, the force was measured based on the magnetic force (MF) compensation principle. This is the first attempt to measure the force directly and statically under arbitrary conditions. One side of a rectangular rotor, which was placed above the acoustic radiation surface, received the holding force. The other side of the rotor received the MF generated by a solenoid. The holding force was estimated from the electric current flowing in the solenoid when the holding force and the MF were balanced. The holding force acting on the rotor surfaces was affected by the deviation between the rotor and the radiation surface. The holding force increased with increasing vibration amplitude or decreasing air gap between the rotor and the radiation surface. When the vibration sources were opposed, the holding force was affected by their vibration phase difference. The holding force was maximum at the opposite vibration phase and decreased with decreasing vibration phase difference. When the vibration sources were arranged in the transportation direction, the transportation force occurred and increased with increasing vibration amplitude of the destination vibration source. These measurement results agree well with the analysis results. [ABSTRACT FROM AUTHOR]

The central magnetic flux density is usually simulated via finite element methods that require a significant amount of inputs and computation resources. We develop the Gaussian process regression (GPR) model to shed light on the statistical relationship between structural descriptors of the iron yoke and the central magnetic flux density for superconducting solenoids. The model is highly stable and accurate, contributing to fast and robust estimations of the central magnetic flux density. [ABSTRACT FROM AUTHOR]

The capability of misalignment tolerance is vital for an inductive power transfer (IPT) system. In this article, a new loosely coupled transformer (LCT) structure with series solenoid and DD pads (SDDP) is proposed to improve the misalignment tolerance of the IPT system. The designed LCT not only has strong misalignment-tolerant capability in the X-direction but also has strong misalignment-tolerant capability in the Y-direction. The fluctuation of mutual inductance is 3.15% within 67.0% misalignment distance of the largest size of the SDDP in the X-direction and 44% misalignment distance of the largest size of the SDDP in the Y-direction. Finally, an LCC/S compensated IPT system with 300 W power is built as an example to demonstrate the performance of the proposed LCT. The output voltage fluctuates with the rated load, which is less than 3.2%, and the efficiency is 90.2–91.3%. [ABSTRACT FROM AUTHOR]

In this study, we developed new bending modules and pneumatic self-excited valves. In a previous study, we developed a planar flexible-deformation mobile robot that combines multiple bending modules. The robot moves by a traveling wave, which is periodically generated by pressurizing air to the bending modules. Further, it can move in every direction by simultaneously combining the two directional traveling waves. However, problems such as air leakage from the bending module that constitutes the moving object and the influence of the moving operation owing to the tubes comprising the flow path were identified. To address these problems, new bending modules have been developed. To address air leak issues, we verified the materials used in the bending modules and developed an injection mechanism. To reduce the number of externally connected tubes, we developed new bending modules that could include multiple internal flow paths. In addition, because the mobile robot moves owing to the generation of traveling waves, it is a low-grade operation. However, this requires multiple solenoid valves and electronic circuits. This is useful if traveling waves can be generated by simply supplying air using a pneumatic self-excited valve. In this study, we developed bending modules with multiple internal channels and a pneumatic self-excited valve that utilizes the snap buckling of leaf springs used in the mobile robot. [ABSTRACT FROM AUTHOR]

Conventional mobile robots typically use a wheel or crawler mechanism for locomotion. However, these robots often get stuck in narrow spaces. To mitigate this issue, we propose an innovative flexible mobile robot named "MOLOOP" in this study. The proposed robot has double-looped and hermetically-sealed structure and all ground-contact-area moves to the same direction. Three synchronized flexible crawlers generate the driving force within the robot body. The crawler, named "HS crawler," comprises of loop-connected flexible bags. The entire body of the robot is flexible; therefore, the robot can pass through narrow terrains with adaptive shape changes. However, in terms of power and size, performance improvement is necessary for the practical use of the robot. This paper describes the improvement of HS crawler performance, which directly affects the driving force, traveling speed, and size of the robot. For the purpose of high input pressure, this study reinforced the flexible bags of the crawler using fibrous materials. This reinforcement realizes the power-up and downsizing of the flexible bags. The new crawler achieves a performance of 3.43 Nm torque and 39.0 mm/s traveling speed, compared to a torque of 0.23 Nm and traveling speed of 3.0 mm/s of the previous crawler. Additionally, the width of the new MOLOOP changed to 270 mm from 420 mm because of the downsized crawler. Furthermore, a dedicated mechanical valve was developed. This valve achieves a flow rate of 2.39 L/min as compared to 0.92 L/min of a commercially available solenoid valve. Moreover, the traveling speed of MOLOOP increased from 3.0 mm/s to 9.0 mm/s. The prototype robot successfully passed through a narrow terrain with a minimum width of 200 mm (robot width: 270 mm). [ABSTRACT FROM AUTHOR]

Copyright of Arab Gulf Journal of Scientific Research is the property of Arabian Gulf University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of FME Transactions is the property of University of Belgrade, Faculty of Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A syringe pump-embedded electromagnetic dispensing and suction (EMDS) system was developed for 3D cell culture in digital microfluidics to overcome the challenges of conventional dispensing technologies. The entire process of droplet 3D cell culture, from cell suspension droplet seeding to culture medium exchange, collection and analysis, has been successfully demonstrated in the EMDS system without the use of additional equipment, demonstrating its potential as a dispensing system for droplet 3D cell culture in microfluidic systems. To integrate sample loading, dispensing, splitting, and collection functions into a single EMDS system, the bi-directional operation of dispensing and suction was implemented using a single solenoid actuator and oil-mediated indirect liquid handling. The system introduces samples via a pipette or chamber insertion, eliminating the hassle of using a syringe such as a syringe filling and providing convenient loading of samples without dead volume issues, even for small sample volumes. Each component of the EMDS system is designed in a modular way and can be assembled in a block assembly type, so it can be configured and replaced easily and flexibly, showing high usability. We hope that with such a high degree of design freedom, the proposed EMDS system can be applied not only to dispensing systems for digital microfluidics but also to microchannels in the near future. [Display omitted] • We developed a syringe pump-embedded electromagnetic dispensing and suction system. • Integrates sample supply and collection into one system using oil-mediated bi-directional actuation. • The EMDS system uses a new approach of introducing sample by inserting a chamber. • Droplet 3D cell culture with EMDS system shows potential as dispensing tool for microfluidic biological applications. [ABSTRACT FROM AUTHOR]

In this paper, we present ion-optical simulation for the design studies of a new solenoid separator as part of the NEXT experiment. Our aim is to separate Neutron-rich, EXotic, heavy nuclei produced in multinucleon Transfer reactions (NEXT) from the primary beam and un-wanted by-products within the magnetic field. The goal of the simulation is to find the optimum arrangement of the components within the NEXT solenoid separator to achieve the highest transmission efficiencies of transfer products and a good suppression of background. In our simulations, we focused on two complementary reactions to produce transfermium isotopes and to produce neutron-rich nuclei around the neutron number N = 126. Transmission yields above 50% for the transfermium isotopes of interest were reached in the simulations. The simulated yields for N = 126 lie between 5% and 20%. [ABSTRACT FROM AUTHOR]

Intense charged particle beams will generally be formed with an initial correlation between their longitudinal properties, including longitudinal variations in current, and their transverse properties, including their radius and divergence. This is due to the competition between the transverse focusing fields in the beam source and the time-varying space charge forces in the beam. In DC electron guns where the current modulation is slow compared to the electron transit time, the nature of these correlations was previously shown to depend on the gun geometry, exhibiting a linear dependence of the beam radius and divergence on the beam current at the gun exit. Here, we extend the previous work to study the transport of beams with such correlation in uniform and periodic solenoid channels. For each transport channel configuration studied, the transverse envelope equation is used to calculate the envelope of 101 beam slices differing in their slice currents, as well as initial radius and divergence (due to their dependence on slice current). For each channel configuration, these calculations are performed 546 times, with each of these iterations considering a different degree of correlation between the radius and divergence, and the slice current. It is found that some degree of correlation between the initial radius and slice current actually aids in beam transport, and the required strength of correlation can be estimated with simple models. Increasing the degree of correlation between the initial divergence and slice current is generally counterproductive, and the degree of sensitivity to such correlations depends on the design of the transport channel. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Development of a fast-stabilized fuel injection system using a solenoid actuator" published in the Journal of Mechanical Science & Technology. The correction addresses an error in the acknowledgment section of the original article, which should have acknowledged support from the Agency for Defense Development by the Korean Government. The correction notice provides the correct acknowledgment and includes contact information for correspondence. [Extracted from the article]

This document is a correction notice for an article titled "Optimization of Dynamic Performance of a Solenoid Actuator in a CNG Injector Based on the Effects of Key Design Parameters" published in the International Journal of Automotive Technology. The correction includes an acknowledgement that the work was supported by the National Research Foundation of Korea and funded by the Korean government. The original article has been corrected, and the publisher remains neutral regarding jurisdictional claims and institutional affiliations. The contact information for one of the authors is provided at the end of the document. [Extracted from the article]

[Display omitted] • A reliable fault diagnosis method based on SPV noise signal is established. • The number of sensors is drastically reduced by using the noise emission of SPVs. • The coherence analyses are conducted to validate effectiveness of the approach. • The number of workers is greatly reduced, especially in aging Chinese plants. The solenoid pulse valve (SPV) is a key component of dust collector. The frequent switch of SPV accelerates its damage, subsequently decrease operation efficiency of dust collector. The traditional manual inspection methods lack reliability and efficiency, while vibration-based condition monitoring is costly and sophisticated in acceleration sensor distribution and signal processing. This paper proposes a fault diagnosis approach based on SPV noise. The average coherence coefficient of SPV noise and vibration signals is above 0.8 and close to 1, which demonstrates that there is a close relationship between SPV noise and its structural vibration. Furthermore, the validation experiments indicate that the SPV fault can be clearly distinguished by its noise signal, confirms the effectiveness of proposed approach. By utilizing this noise monitoring method, the number of sensors can be reduced by about 95 %, the work intensity of the staff is greatly reduced, and production efficiency and safety are guaranteed. [ABSTRACT FROM AUTHOR]

• An innovative permanent ring, the hollow-plunger-type magnet radial shape, is presented to improve the transient behaviors of HSVs. • The permanent magnet radial ring is beneficial to suppress the undesirable skin effect of the solenoid. • Different energy distribution characteristics of conventional HSV and the innovative HSV are analyzed. • With the increase of thicknesses and heights of the permanent magnet ring, the transient performance of the HSV have been greatly improved. The transient behavior and energy transmission of a global type solenoid for high-speed valve (HSV) depend upon the magnetic force acting on the sphere. Rapid responses are challenging to achieve because of the limited power supply energy, which makes it hard to optimize the magnetic force through its own structural characteristics for HSV. Aiming to obtain higher magnetic force without increasing the input electric power, an innovative magnet radial ring is presented and a relative evaluation of magnetic forces exerted on a global type solenoid for HSVs is conducted. A hollow-plunger-type magnet radial ring is engineered as a novel magnet ring form. The magnetic forces and transient action time of the conventional HSV and innovative HSV are evaluated by means of finite element method (FEM) analysis and demonstrated by verification of the experimental data. The assessment of the magnetic forces involves every solenoid with a diverse magnet ring shape with the variation of height and thickness. The suggested novel magnet ring successfully increases the magnetic force applied to the sphere by changing the internal magnetic connection structure and increasing the mechanical energy conversion ratio, according to a methodical comparison of the two HSVs' transient performances. Meanwhile the innovative magnet ring can reduce the strength of iron loss occurred in the magnetic field of HSV to realize the reduction of useless power loss. At the magnetization position at the attraction, the magnetic force is 17.35 N, while the magnetic ring increases the magnetic force to 28.84 N. Also, the maximum rising speed of the magnetic force is improved from 14945 N/ms to 38904 N/ms, and the transient action time is reduced from 3.74 ms to 1.30 ms. For the mechanical energy and iron loss energy in energy conversion occurred in solenoid, the mechanical energy ratio increases from 16.2 % (conventional valve) to 27.8 % (innovative valve) with height 26 mm and thickness 3.5 mm, while the iron loss energy ratio decreases from 40.7 % (conventional valve) to 31.8 % (innovative valve) synchronously. [ABSTRACT FROM AUTHOR]

• We propose for the first time a good linear relation between the area value of the temperature rise curve and the temperature for different sensing lengths of the screwed tube both theoretically and experimentally. • For the first time, we use the difference operation in the temperature rise curve, which can well reduce the influence of system noise on solving the bottom width of the temperature rise curve. • We propose for the first time to construct in advance a three-dimensional surface of the sensing length of the screwed tube-temperature-area value, and combine the length of the temperature variation region (TVR) and the area value of the temperature rise curve affected by the TVR, so that the temperature of the TVR can be well demodulated. • We present a solution for obtaining high temperature accuracy and high spatial resolution temperature sensing by choosing a larger screwed tube radius and a smaller sampling rate of the data acquisition card. • We show that optimizing the noise of the system, choosing a smaller pitch of the screwed tube and increasing the number of winding of the sensing fiber in each groove, high spatial resolution and high temperature accuracy can be obtained with a smaller radius of the screwed tube. Limited by the large bottom width of the pulsed light and the large sampling spacing of the data acquisition card in conventional Raman distributed temperature sensing (RDTS) systems, short straight fibers cannot acquire temperature measurements with high spatial resolution and high temperature accuracy in a single temperature variation region (TVR). In contrast, winding sensing fiber on a screwed tube as a fiber solenoid for temperature sensing can indirectly improve the spatial resolution of the system. However, as the radius of the screwed tube decreases, the ability of the screwed tube to improve the spatial resolution of the system will deteriorate. To break this limitation, we innovatively propose a signal processing scheme to first construct a three-dimensional surface of the sensing length of screwed tube-temperature-area value, then obtain the length of the TVR and the area value of the temperature rise curve generated from a single TVR, and finally demodulate the temperature of the TVR in the surface. The experimental results show that the proposed scheme improves the spatial resolution of the conventional screwed tube from 8 cm to 1 cm, and the average temperature accuracy of the three TVRs with the interval and length of the TVRs in the order of centimeters is ± 0.63 °C. The screwed tube can be used for axial temperature distribution measurements of liquids as well as solids, and the proposed method can further expand the application prospects of the RDTS system for continuous measurement of multiple TVRs with lengths and intervals of centimeters in one direction without changing the internal hardware. [ABSTRACT FROM AUTHOR]

In this paper, a one-bit reconfigurable reflective metasurface is proposed by electromagnetically wideband elements is proposed. The element has a double-layer structure, the lower dielectric plate is driven by a electromagnetically push-pull solenoid to adjust the air layer thickness between top layer. The element has a wideband characteristic, the phase difference between 1 bit and 0 bit in 9.3 GHz–16 GHz is 180° ± 10°and the bandwidth of the unit reaches 53.6%. A 12 × 12 prototype was then designed, simulated and measured at 10 GHz, 12.5 GHz and 15 GHz. The maximum gain is 18.4 dBi, 19.08 dBi, 18.8 dBi. The aperture efficiency is 13.51% at 12.5 GHz. The 3 dB bandwidth is 16%, and the main beam can scan range of ±40°at the centre frequency. [ABSTRACT FROM AUTHOR]

We propose a new linear solenoid actuator design to create a solenoid micropump targeting portable microfluidic systems. A novel solenoid actuator design was developed with a unique arrangement of two magnets, which provides a fundamental solution to the inherent problem of force variation in conventional solenoid pumps. Central to the technique is the antisymmetric force distribution of the two magnets in an opposing orientation with a suitable spacing between them. Through a mathematical model and systematic parametric study, we verified that the proposed linear solenoid actuator could provide up to 99.9% constant force source with fast response time and pulsation-free flow in small system size using direct current (DC) power. In addition, the general design rule of the proposed solenoid actuator was found through dimensional analysis. The proposed design is implemented into more practical solenoid micropumps for microfluidic applications such as flow focusing and droplet manipulation in digital microfluidics through our series work. We hope this study will promote the development of various actuators for microfluidics and contribute to the broader application of microfluidics in more fields. [Display omitted] • A novel linear solenoid actuator design for portable microfluidics is proposed. • It fundamentally solves the problem of force variation in a solenoid. • It provides a constant force source without pulsation in a small system size. • General design rules of the proposed solenoid are provided. • The proposed design is implemented into more practical actuators in our series work. [ABSTRACT FROM AUTHOR]

Magnetic microrobots can be miniaturized to a nanometric scale owing to their wireless actuation, thereby rendering them ideal for numerous biomedical applications. As a result, nowadays, there exist several mechano‐electromagnetic systems for their actuation. However, magnetic actuation is not sufficient for implementation in biomedical applications, and further functionalities such as imaging and heating are required. This study proposes a multimodal electromagnetic system comprised of three pairs of Helmholtz coils, a pair of Maxwell coils, and a high‐frequency solenoid to realize multimodal locomotion and heating control of magnetic microrobots. The system produces different configurations of magnetic fields that can generate magnetic forces and torques for the multimodal locomotion of magnetic microrobots, as well as generate magnetic traps that can control the locomotion of magnetic swarms. Furthermore, these magnetic fields are employed to control the magnetization of magnetic nanoparticles, affecting their magnetic relaxation mechanisms and diminishing their thermal properties. Thus, the system enables the control of the temperature increase of soft‐magnetic materials and selective heating of magnetic microrobots at different positions, while suppressing the heating properties of magnetic nanoparticles located at undesired areas. [ABSTRACT FROM AUTHOR]

In this work, we experimentally investigate the current carrying capacity of single REBCO tapes and stacks made 5 12 mm REBCO tapes with a 25 μm copper stabilizer in liquid helium in comparison with those made of bare tapes with no stabilizer at current ramp rates up to 55 kA/s. The motivation for the research was checking the usability of REBCO stacks as basic sub-elements for high current superconducting cables operating in fast cycling modes at 4.2 K. An original experimental technique was employed to induce the extremely high ramp rates. During the tests, one or 5-folded stacks curled into rings 95 mm dia with different types of joints were charged in the external magnetic field generated by an outer solenoid at ramp rates up to 1.6 T/s. The curled REBCO stacks were either soft-soldered over their entire length or contained local joints only. The maximum screening current induced in the samples during the outer solenoid charging Imax was registered. Our experiments showed that the current carrying capacity of the REBCO tapes and stacks was strongly affected by the absence or presence of the copper stabilizer as well as the type of the joint. The reasons for the Imax limitation for the copper stabilized and bare samples are also briefly discussed. [ABSTRACT FROM AUTHOR]

How to design an impact platform that can provide a strong electromagnetic environment for all kinds of precision electronic equipment and experimental reference for strong electromagnetic protection is of great significance. In this article, an electromagnetic coil system that generated a strong magnetic field environment was designed and studied. First, the coil parameters and coil structure were designed. Then, the Comsol finite element software was used to simulate and design the three-component coil. The coil distance and turns were adjusted to make the coil center produce a uniform magnetic field area and meet the strong magnetic field index. Finally, the coil system was built to verify the magnetic field generated by the coil through experiments. This system will be used to simulate the strong magnetic field environment that produces different high precision and may occur in the operating environment of the equipment. It will also be used to provide strong magnetic field impact test support conditions for aerospace, naval vessels, and various types of equipment, so as to find and solve the problem of antistrong magnetic reliability of equipment in the design stage. [ABSTRACT FROM AUTHOR]

Safety instrumented systems (SIS), also known as emergency shutdowns, interlocks, and trips, are very common and critical safeguards protecting process plants. In order to maintain and test these systems, they are usually implemented with well‐engineered and controlled bypasses, typically including alarm logging, bypass authorization, and auditing. Even so, there are myriad ways to place an SIS component into bypass, sometimes without even realizing it. Many of these methods occur in the field, away from the watchful eye of the board operator. In many cases, the bypasses occur inadvertently during maintenance or operational activities and are left in place, unmanaged. Common culprits include solenoid valve latches, shutoff valve handwheels, and hand‐off‐auto switches on pump and compressors. This paper will explain how some equipment can be inadvertently put into bypass and methods for documenting and verifying that they are not in bypass using advanced mobile computing assisted car‐seal management. [ABSTRACT FROM AUTHOR]

This paper presents aspects related to the use of a cylinder with two piston rods. Beside a multiposition cylinder, it is a pneumatic actuator. In this article two kind of circuits using a multi-position cylinder are presented: one pneumatic circuit and one electro-pneumatic circuit. The pneumatic circuit comprises the following devices: compressed air supply, a start-up valve with filter control valve, a 5/2 way solenoid valve, a 3/2 way solenoid valve and a multi-position cylinder. Furthermore, an electro-pneumatic circuit comprises: compressed air supply, an air filter, a 5/2 way solenoid impulse valve, a 3/2 way solenoid valve, a multiposition cylinder, relay, lamp and a valve solenoid. The design and simulation of both schemes from this article is done in FluidSim software from Festo. [ABSTRACT FROM AUTHOR]

A ferromagnetic helix magnetized axially or radially is apparently the simplest helical undulator. Four helices with alternating magnetization can provide a stronger helical field than a pair of conventional planar Halbach arrays. Such undulators and microundulators seem promising for various powerful high frequency sources. The fields of infinite helices uniformly magnetized in the longitudinal and radial directions are found analytically by integration of contributions from elementary dipoles. The analytical values of the field magnitudes are close to the numerically calculated ones for a helix with a relatively small number of periods five–ten. According to simulation, a magnitude of about 1 T can be obtained on the axis of a system of helices with small inner radii. [ABSTRACT FROM AUTHOR]

This paper presents a state-averaged model and the design of nonlinear observers for an on/off pneumatic actuator. The actuator is composed of two chambers and four on/off solenoid valves. The elaborated state-averaged model has the advantage of using only one continuous input instead of four binary inputs. Based on this new model, a high-gain observer and a sliding-mode observer are designed using the actuator position and the pressure measurements in one of the chambers. Finally, their closed-loop performance is verified and compared on an experimental benchmark. [ABSTRACT FROM AUTHOR]

A three-stage-five-coil inductive power transfer (IPT) system which is based on cylindrical solenoid coupler (CSC) is proposed in this article. The shape and parameters of the CSC are optimized. The five litz coils compensated by series capacitors are considered to form an IPT system based on equivalent CLC/S/CLC compensation topology with constant voltage characteristics. The mutual inductance between compensation auxiliary coil (CAC) and power transfer coil could be changed by moving the position of CAC, and the freedom of parameter design is enhanced. Mathematical model and loss model of the system are established, and power transfer characteristics of the system are analyzed. The system is considered to be used as a power source for state detection equipment of high-voltage (HV) device to achieve long-distance IPT, the effect of the coupler on the HV electric field is verified. Finally, a prototype with a length of 1.54 m was built. Based on the platform, output voltage and dc–dc power transfer efficiency curves with changed input voltage and load are obtained. The maximum efficiency of the dc–dc system can reach about 60%. [ABSTRACT FROM AUTHOR]

This article represents research regarding use of pneumatic linear actuator. A pneumatic linear drive is a device that creates motion in a straight line. The linear drive with solenoid in this manuscript is a pneumatic actuator. The pneumatic linear drive works only with compressed air. Compressed air usually has a pressure of between 2•105 Pa and 6•105 Pa. Linear drive with solenoid can be used for various applications, including pulling/pushing, pick-and- place applications or lifting/moving. After Introduction, the authors study two pneumatic circuits using linear drive with solenoid coupling. In fact, the first pneumatic scheme in this paper has only one device (linear drive 1-1). But, the second pneumatic circuit has two actuators (linear drives 2-1 and 2-2). Further on, the authors present two electro-pneumatic circuits. In any case, a simple electro-pneumatic circuit that has a linear drive with solenoid coupling. Moreover, the second electro-pneumatic system has a linear drive with solenoid coupling and PLC (Programmable Logic Controller). The pneumatic and electro-pneumatic circuits given in this manuscript are made using FluidSim software from Festo. [ABSTRACT FROM AUTHOR]

The power generation capability of an electromagnetic vibration energy harvester augmented with an additional coil was investigated and compared with that of a standard single coil electromagnetic energy harvester. A single degree of freedom model and the corresponding equivalent electric circuit were employed for the analysis of the standard and of the augmented harvesters. The harvester model was validated by means of an accurate experimental characterization of a commercial electromagnetic harvester, i.e., the model-D by ReVibe. The electric circuits for the standard and for the augmented harvesters were implemented by electronic components and experimentally tested to determine the maximum power they are able to generate in four test conditions. Results from simulations and from experiments showed significant improvement of the power extraction performance exhibited by the double coil energy harvester, particularly at frequencies lower than the harvester mechanical resonance frequency. [ABSTRACT FROM AUTHOR]

We study leading order singularities of the wave trace of the Aharonov–Bohm Hamiltonian on R 2 with multiple solenoids under a generic assumption that no three solenoids are collinear. Then we apply our formula to get a lower bound of scattering resonances in a logarithmic neighborhood near the real axis. [ABSTRACT FROM AUTHOR]

A novel stacked magnetic pendulum array (MPA) is proposed as an antenna for efficient transmission in ultralow frequencies (ULF). The MPA structure consists of an array of ${m\times n}$ magnets stacked in $n$ rows (m magnets of the same magnetization per row) and a solenoid that encompasses the array. The magnetic flux generated by the solenoid couples to the magnets through a mechanical motion and creates a strong time variant magnetic field at the resonance frequency of the array. The proposed MPA is developed utilizing bearings with extremely small damping which hold the magnets, enable efficient oscillation, and guarantees a high-quality factor ($Q$ -factor). A comprehensive analysis to study the performance of the MPA and a conventional solenoid will be provided and accordingly, characteristics of an arbitrary ${m\times n}$ array in terms of field strength, resonance frequency, transmission efficiency and inductance are studied. Furthermore, a figure of merit (FOM) is introduced as the ratio of efficiency to the maximum linear dimension of the antenna. The experimental results for a fabricated $5 \times 11$ array show a resonance frequency of 715 Hz and a Q-factor of 94 while the maximum linear dimension of the antenna is just 9 cm. Moreover, measurement results show 24.9 dB improvement in the transmission efficiency of the MPA compared to the efficiency of a single solenoid of the same dimensions. The MPA has the FOM of ${1.26\times 1}{0}^{{4}}$ which is noticeably higher than that of proposed antennas in the literature. To demonstrate broadband transmission with the MPA, a binary frequency shift keying (BFSK) signal is transmitted through the use of direct antenna modulation (DAM) at a rate of 18 bps. [ABSTRACT FROM AUTHOR]

ESC's solenoid valves independently brake each wheel, allowing the vehicle to maintain braking and directional stability. The most important component of the solenoid valve is the armature manufactured by the turning process by a CNC lathe so far. In this study, we propose to use the multi-stage cold forging process as an alternative to reduce manufacturing cost while satisfying dimensional accuracy and performance. To apply the multi-stage cold forging process, the whole forming process is divided into six stages to improve the dimensional accuracy of the outer diameter, full length and slot part of the armature. It is divided into 6 stages, but 6 stages are operated simultaneously in one stroke of forging. Inducing uniform plastic deformation by designing the preform for each stage of the armature slot. Through the proposed process design for the multi-stage cold forging process, the dimensional accuracy of the test product can be improved. The weight of the input material in the turning process can be reduced by 46 % from 3.5 g to 1.9 g by applying the multi-stage cold forging process. In addition, the manufacturing process can be reduced from 2 processes to 1 process, and the production quantity can be increased by 2500 % from 180 ea to 4800 ea per hour. [ABSTRACT FROM AUTHOR]