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The influence of key design parameters on the constant force characteristics of long-stroke moving-iron proportional solenoid actuators (MPSAs) has been explored by a method combining finite element modelling and correlation analysis. First, the finite element model (FEM) of long-stroke MPSA was developed and validated. Subsequently, the two evaluation indexes, the average-output solenoid force and maximum-output solenoid force variability, were introduced to disclose the influence law of pole shoe parameters on the constant force characteristics of a long-stroke MPSA. After that, correlation analysis was employed to quantify the influence of several parameters and parameter interaction factors on the constant force characteristics. The results indicate a strong contradiction between the average-output solenoid force and maximum-output solenoid force variability; however, increasing the inner diameter of the cone helps enhance the average-output solenoid force without causing maximum-output solenoid force variability to increase. Among all the parameters examined, the cone angle is the most significant parameter affecting the constant force characteristics. Additionally, interactions between the cone angle and the cone length, the cone angle and the inner cone diameter, the cone angle and the outer cone diameter, the cone length and the outer cone diameter, as well as the inner cone diameter and the outer cone diameter also have an important influence on the constant force characteristics. This study deepens our understanding of how the key parameters affect the constant force characteristics and assists designers in optimizing these parameters for developing new structures. [ABSTRACT FROM AUTHOR]

The counter-pressure casting (CPC) process has the technical advantages of smooth filling and solidification under pressure, which is conducive to obtaining high-quality castings. In the counter-pressure casting process, the way of fixed solenoid valve opening is used for synchronous pressurization at present. However, this synchronous pressurization method causes the melt to rise first in the transfer tube and then fall back. The falling process of the melt will lead to the formation of the double-layer oxide films on the melt surface. In the subsequent pouring stage, part of the double-layer oxide films will enter the inside of the casting to form defects. To solve this problem, the synchronous pressurization process was optimized. Combined with numerical simulation and measurement results, the influence of two kinds of processes on melt rise behavior in transfer tubes before and after optimization is compared. The optimized process can reduce the rise height of melt by about 90% in the process of synchronous pressurization and change the flow behavior of melt so that the melt is always filled forward and the fall of melt is eliminated. Furthermore, the formation of double-layer oxide films in the melt during synchronous pressurization is eliminated. [ABSTRACT FROM AUTHOR]

We show that Kellendonk’s tiling semigroup of a finite local complexity substitution tiling is self-similar, in the sense of Bartholdi, Grigorchuk and Nekrashevych. We extend the notion of the limit space of a self-similar group to the setting of self-similar semigroups, and show that it is homeomorphic to the Anderson–Putnam complex for such substitution tilings, with natural self-map induced by the substitution. Thus, the inverse limit of the limit space, given by the limit solenoid of the self-similar semigroup, is homeomorphic to the translational hull of the tiling. [ABSTRACT FROM AUTHOR]

In this paper, we construct odd finitely summable spectral triples based on length functions of bounded doubling on noncommutative solenoids. Our spectral triples induce a Leibniz Lip-norm on the state spaces of the noncommutative solenoids, giving them the structure of Leibniz quantum compact metric spaces. By applying methods of R. Floricel and A. Ghorbanpour, we also show that our odd spectral triples on noncommutative solenoids can be considered as inductive limits of spectral triples on rotation algebras. In the final section, we prove a noncommutative version of Wiener's lemma and show that our odd spectral triples can be defined to have an associated smooth dense subalgebra which is stable under the holomorphic functional calculus, thus answering a question of B. Long and W. Wu. The construction of the smooth subalgebra also extends to the case of nilpotent discrete groups. [ABSTRACT FROM AUTHOR]

The punching machine is a mechanical equipment that is widely used in leather cutting. To facilitate mass production, both the punching table and layout are designed to accommodate long strokes over a large area. This enables one-time automatic continuous punching of large leather sheets. However, as the punching layout increases in size, it becomes more difficult to maintain the equal distance of the die cutter and table plate. Moreover, the table plate is overlaid with a polypropylene (PP) punching pad that is approximately 25 mm thick. Although it acts as a buffer to preserve the sharpness of the die, it causes cumulative deformation and defects in the die after repeated punching. Additionally, there often exists a height deviation of approximately 1–2 mm between the die and the punching pad at different positions. As the thickness of the leather sheet is often between 0.1 and 2 mm, automatic punching has a few drawbacks; although the leather is cut completely according to the set depth in some areas, other areas of the sheet might be over- or under-cut. This results in excessive consumption of the die or punching pad or generates excessive waste at the locations where the cutting is incomplete. To determine the effective punching stroke for a large layout (1.2 m × 2.2 m), this study proposes the innovative method of using the object packing as the reference to obtain the actual depth of the punching point for each die through automatic search before automated mass production. The results are then recorded in the packing system. In addition, the control delay time of the hydraulic solenoid valve is obtained from signal analysis. This approach enables the adjustment of the punching depth, to punch and cut the leather material successfully in a large layout. Moreover, the depth of the die mark left in the punching pad is restricted to a value between 0.1 and 0.2 mm. This effectively increases the life of the die and reduces the consumption of the punching pad, greatly improving the accuracy and stability of the punching system. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a new algorithm for calculating the radial and axial magnetic forces between two non-coaxial circular loops with parallel axes. These formulas are derived from a modified version of Grover's formula for mutual inductance between the coils in question. Utilizing these formulas, we compute the radial and axial magnetic forces between two non-coaxial thick coils of rectangular cross-sections with parallel axes. In these calculations, we apply the filament method and conduct investigations to determine the optimal number of subdivisions for the coils in terms of computational time and accuracy. The method presented in this paper is also applicable to all conventional non-coaxial coils, such as disks, solenoids, and non-conventional coils like Bitter coils, all with parallel axes. This paper emphasizes the accuracy and computational efficiency of the calculations. Furthermore, the new method is validated according to several previously established methods. [ABSTRACT FROM AUTHOR]

RFID (Radio Frequency Identification), which transmits control data through electronic tags in a non-contact manner, provides a new approach for efficient and low-cost remote control of oil downhole tools. However, the interference of harsh downhole environments and the high-speed movement of tags seriously affect the performance of the current downhole reader. To effectively address this issue, in this study, a novel downhole RFID reader is presented. By introducing the half-duplex communication protocol to replace the current full-duplex communication protocol in the hardware circuits of the reader, its tag recognition ability can be improved. Then, the corresponding hardware circuits and software programs are designed. Furthermore, a sparse solenoid antenna is adopted to replace the traditional tightly wound solenoid antenna, which can provide a longer reading area range to cope with the high-moving tag, and its total length and spacing parameters between adjacent coils are designed in detail. The test results show that the proposed RFID reader based on a half-duplex communication protocol can communicate with tags normally, and its sparse solenoid antenna provides significantly more tag reading times than traditional tightly wound solenoid antennas under the same antenna inductance. [ABSTRACT FROM AUTHOR]

The maximum radial size of the conventional three-bit four-way electromagnetic cartridge valve is greater than the largest containable size of the fluid control valve used for downhole robots. This paper proposes two kinds of solutions to reduce the radial dimension of the three-bit four-way electromagnetic insertion valve: one is to reduce the radial arrangement of the coil and increase the axial arrangement of the coil, and the other is to reduce the diameter of the moving iron core to reduce the winding radius of the coil. Using the theoretical model established in the following text, a simulation experiment was conducted. The results show that the movement of the valve spool is basically completed within 30 ms. Then, a matching experiment on the electromagnetic insertion valve was designed and conducted. The experimental results show that the opening time of the solenoid valve on the left coil is about 52 ms, and the opening time of the solenoid valve on the right coil is about 44 ms. The reaction time of the valve spool is suitable for the practical application of the solenoid valve. The significance of this paper is the reduced radial size of the three-bit four-way electromagnetic insertion valve. These improvements have reduced the size of downhole drilling robots, which facilitates the application of downhole drilling robots in narrower environments. [ABSTRACT FROM AUTHOR]

This paper presents an experimental setup of magnetic field taper variations to optimize the efficiency of a Ka-band pulsed gyrotron. Experimental optimization of the gyrotron's efficiency is presented. The efficiency dependence on three input parameters—beam current, magnetic field amplitude, and variations in the magnetic field taper profile—is studied. A gyrotron electron efficiency improvement from 25.4% for a non-tapered magnetic curve to 36.4% for a tapered magnetic curve is measured. The stability of the millimeter wave excitation in the cavity is also affected by the magnetic taper gradient. The magnetic taper is obtained by a practical modification of the solenoid that leads to an 11% electron efficiency improvement. Magnetic tapering can be combined with other types of efficiency enhancement concepts to obtain an overall improved efficiency that can be important for industrial applications. [ABSTRACT FROM AUTHOR]

• Commercial-of-the shelf (COTS) space qualified solenoid valves for small satellite missions are financially unviable. • Thrusters control spacecraft attitude, the response time, and parameters of the solenoid valve is critical in mission design. • A mathematical model was developed to find the optimized geometrical configuration of the solenoid valve. • This paper presents a practical solution for designing custom solenoid valves. • The developed mathematical model validated using COTS space qualified solenoid valves. Small satellites and spacecrafts use propulsion systems to stabilize their attitude, control orientation and deorbit it at the end of the mission life. The flow and thrust of the liquid propulsion system are controlled by the control valve, typically operated by solenoid. According to recent literature, space-qualified solenoid valves are expensive and financially non viable, especially for small satellite missions. In this paper, a detailed methodology is presented to design the solenoid valve dedicated for small satellites. This study includes design criteria focusing on geometrical configuration. The dynamic, and electro-magnetic models are used to characterize the solenoid valve. Dynamic modelling helps to determine the response time of valve, affecting the thruster minimum impulse bit. The physical dimensions of the designed solenoid valve are smaller than those available in commercial off-the shelf (COTS) solenoid valves. However, the efficacy of the proposed design is proven effective with the COTS space grade valve specifications, and it shows that the proposed valve consumes less power than the conventional valves. Finally, it is worth noting that despite their modest and compact physical dimensions, the proposed valve are ideal for small satellite missions. [ABSTRACT FROM AUTHOR]

In order to solve the problems of bottom pod leakage and soil removal by header, a soybean header profiling system was designed in this paper. The cutter height off-ground detection device was installed on both sides of the header, and the cutter distance from the ground was represented by the angle sensor turning when the profiling wheel met the rolling ground. The hydraulic electromagnetic reversing valve was installed so that the profiling system could automatically control the lifting of the header, the unilateral power of the solenoid valve was 0.15 s, and the height of the cutter from the ground was changed by 10 mm. The height of the cutter off the ground was set to 80 mm, and the adjustment range of the soybean header profiling system was 45–125 mm. The test results showed that the maximum absolute error of the cutter off the ground height detection device was 5.98 mm, the minimum absolute error was 1.00 mm, and the relative error was 0.038. The cutter height adjustment device was powered for 0.15 s, and the average adjustment distance was 11.158 mm. The soybean header profiling system did not shovel soil during field harvest, and the stubble height of 85% of soybean plants was less than 10 mm from the set height after harvest. The results showed that the soybean header profiling system could effectively adjust the cutter height from the ground so that the cutter height from the ground was kept at 80 mm. This study could provide a reference for the intelligent design of soybean harvesters. [ABSTRACT FROM AUTHOR]

Electromagnetic forming (EMF) has shown considerable promise in lightweight alloy tube manufacturing industry. However, the generated force field falls short of meeting the stringent forming accuracy requirements for variable-diameter tubes. To solve this, this paper proposes an EMF process using a novel coil structure, named as segmented coil, to improve the forming quality of tubes. The design and implementation of coil, as well as the deformation behavior of tubes, are discussed. Results show that a multi-layer solenoid coil can generate excessive force on the upper portion of the tube, thus causing an undesired gap between the coil and tube that is unfavorable for forming performance. In contrast, when employing a segmented coil, the force applied to this section is mitigated, allowing the tube to fit into the die from bottom to top and achieving a maximum die-fitting gap of no more than 0.1 mm. Besides, it is found that the forming accuracy increases with increasing discharge energy, and an optimal coil structure exists when the discharge energy is fixed. This work showcases the considerable flexibility of the segmented coil in controlling the Lorentz force distribution and tube deformation behavior. These findings hold significant implications for expanding the applications of EMF technology. [ABSTRACT FROM AUTHOR]

In view of the problem that the output thrust of the solenoid actuator is affected by various factors and is difficult to calculate in actual working conditions, this paper proposes a semi-analytical model constructed by magnetic field subdomain method with internal and external boundary conditions in a cylindrical coordinate system for calculation, and the general solution equations of magnetic vector potential for each subdomain are derived and solved by MATLAB. Taking a push–pull electromagnet as an example, the finite element simulation and experimental comparative analysis are carried out. The correctness and applicable conditions of the subdomain method are illustrated by comparing the gradient plot of magnetic vector potential, inductance curve and electromagnetic force. It is shown that the results calculated by the subdomain method are very close to the finite element method when the magnetic saturation problem is neglected. However, when the nonlinearity of core permeability is considered, the magnetic saturation gradually deepens with the increase in current, and the error of the subdomain method calculation results gradually increases. Through simulation and experimental verification at slight magnetic saturation, the output thrust after considering the core gravity, spring force and electromagnetic force, it is shown that this method has the advantage of computational flexibility compared with the finite element method, and it is easier to write special algorithms according to various working conditions to calculate the important parameters in engineering applications. [ABSTRACT FROM AUTHOR]

The basic physics of magnetic fields is presented for a target audience of NMR workers. This group often does not have formal training in electromagnetism, but could benefit from an understanding of a selected subset of topics. The focus here is on a relatively non-mathematical view, intended to deliver an intuitive understanding of the topic. The covered topics start with the fields arising from simple idealized currents, including long straight wires, short flat coils, infinite current sheets, long solenoids, and magnetic dipole moments. The generation of field gradients and shim fields is discussed. All of these can be unified by considering the divergence and curl of the magnetic field. Magnetic materials are treated, both linear magnetizable materials (including the sample itself) and permanently magnetized materials; the approaches of equivalent currents and Ampere's theorem for magnetic circuits are presented.

Introduction: During the COVID-19 pandemic, ventilator shortages necessitated the development of new, low-cost ventilator designs. The fundamental requirements of a ventilator include precise gas delivery, rapid adjustments, durability, and user-friendliness, often achieved through solenoid valves. However, few solenoid-valve assisted low-cost ventilator (LCV) designs have been published, and gas exchange evaluation during LCV testing is lacking. This study describes the development and performance evaluation of a solenoid-valve assisted low-cost ventilator (SV-LCV) in vitro and in vivo, focusing on gas exchange and respiratory mechanics. Methods: The SV-LCV, a fully open ventilator device, was developed with comprehensive hardware and design documentation, utilizing solenoid valves for gas delivery regulation. Lung simulator testing calibrated tidal volumes at specified inspiratory and expiratory times, followed by in vivo testing in a porcine model to compare SV-LCV performance with a conventional ventilator. Results: The SV-LCV closely matched the control ventilator's respiratory profile and gas exchange across all test cycles. Lung simulator testing revealed direct effects of compliance and resistance changes on peak pressures and tidal volumes, with no significant changes in respiratory rate. In vivo testing demonstrated comparable gas exchange parameters between SV-LCV and conventional ventilator across all cycles. Specifically, in cycle 1, the SV-LCV showed arterial blood gas (ABG) results of pH 7.54, PCO2 34.5 mmHg, and PO2 91.7 mmHg, compared to the control ventilator's ABG of pH 7.53, PCO2 37.1 mmHg, and PO2 134 mmHg. Cycle 2 exhibited ABG results of pH 7.53, PCO2 33.6 mmHg, and PO2 84.3 mmHg for SV-LCV, and pH 7.5, PCO2 34.2 mmHg, and PO2 93.5 mmHg for the control ventilator. Similarly, cycle 3 showed ABG results of pH 7.53, PCO2 32.1 mmHg, and PO2 127 mmHg for SV-LCV, and pH 7.5, PCO2 35.5 mmHg, and PO2 91.3 mmHg for the control ventilator. Conclusion: The SV-LCV provides similar gas exchange and respiratory mechanic profiles compared to a conventional ventilator. With a streamlined design and performance akin to commercially available ventilators, the SV-LCV presents a viable, readily available, and reliable short-term solution for overcoming ventilator supply shortages during crises. [ABSTRACT FROM AUTHOR]

McKibben pneumatic actuators (MPAs) are soft actuators that exert tension by applying compressed air to expand a rubber tube. Although electro-pneumatic regulators can control air pressure, most are large and expensive. This study utilizes a dynamic quantizer to control the MPA with a small solenoid valve that can only open and close the valve instead of an electro-pneumatic regulator. A dynamic quantizer is one of the quantizers that converts continuous signals to discrete signals. Our previous study confirmed that tension control of MPA under isometric conditions could be realized using a dynamic quantizer. However, it is often necessary to control the length of the MPA as well as the tension of the MPA. This study implements a dynamic quantizer to control the length of the MPA with a small solenoid valve. Numerical simulations and experimental tests verify the effectiveness of the proposed method. The results of the numerical simulations and experimental tests confirmed that the length of the MPA can be controlled using the dynamic quantizer. [ABSTRACT FROM AUTHOR]

This paper describes the procedure for creating a electronic simulation model of a solenoid power electronic driver with a nonlinear inductive load. Furthermore, it discusses the electromagnetic interaction between the driver and the load example electromagnetic valve. The consideration of nonlinear effects in the power electronic components MOSFET and diode is particularly important to distinguish their effects from the nonlinear behaviour of the inductive load. [ABSTRACT FROM AUTHOR]

A fundamental understanding of the theory and measurement procedures for characterizing a solenoid is crucial for making a project cost-effective and achieving the desired performance for its use in a LINAC. This paper attempts to comprehend the beam dynamics of charged particles by considering the conservation of canonical angular momentum, which can take on positive, negative, and zero values. The analytical expression to generate a parallel beam using a solenoid is derived. The effect of the final beam size on the values of a solenoid's spherical aberration coefficient and the position of the minimum beam size with respect to the focal length is studied using electron trajectories. A practical procedure to tune the above two parameters of a solenoid is demonstrated by simply modifying the demountable disks connected at each end. A mathematical model is proposed to accurately determine the axis of a solenoid and the magnetic centre using the measured magnetic field data, which is validated experimentally. Several solenoids, used in the 9.5 MeV 10 kW electron LINAC suitable for sterilizing medical products and food irradiation, have been characterised using this procedure. [ABSTRACT FROM AUTHOR]

Spot sprayers that can distinguish between different types of plants, such as weeds and crops, have recently been introduced into the field. These sprayers are all equipped with a system capable of recognising and spraying individual plants. These components are not included in existing test procedures for testing sprayers in use. In order to investigate the applicability of existing test procedures, the Ecorobotix spot sprayer was tested according to EN ISO 16122. With a few exceptions due to additional functionalities, this standard is well suited for carrying out such a test on spot sprayers in use. The entire electronic detection system, consisting of camera, computer and solenoid valve system, has to be tested with new test procedures. The positive experience with the use of protocols for band sprayers leads to the conclusion that they can also be applied to the testing of spot sprayers, but must be extended to test the new elements of these sprayers. [ABSTRACT FROM AUTHOR]

The magnetic field method for preparing aligned steel fiber-reinforced concrete (ASFRC) by solenoid coil has a limitation, which is that the specimen must be placed inside the solenoid coil, limiting its practical engineering application. To overcome this shortcoming, this study proposes a method for preparing ASFRCs using an external magnetic field created by assembled magnets. A theoretical model is proposed to predict the distribution of the external magnetic field and the orientation coefficient of ASFRCs prepared by assembled magnets. The predicted results are compared with the experimental results to verify the proposed model. Finally, flexural tests are used to compare the mechanical characteristics of ASFRCs prepared using assembled magnets and solenoid coil. The results indicate that the assembled magnets can be used to prepare the ASFRC with an orientation coefficient of 0.9 or higher, and the flexural strength is similar to that of the ASFRC prepared by the solenoid coil. [ABSTRACT FROM AUTHOR]

Students may calculate the mutual inductance between an infinite solenoid and a surrounding circular loop using an incorrect method that yields the correct answer, causing frustration and confusion. A physical explanation for the agreement of the two methods is provided that is based on the translational symmetry of the solenoid. As a consequence, the conclusion generalizes to infinite uniform solenoids of arbitrary cross section. When students obtain the right answer using an unjustified method, instructors are faced with a grading quandary. Finding himself in that situation, this author asked, "Why?" The resulting paper, which will be enjoyed by instructors of electromagnetism, shares the explanation, involving the mutual inductance of a solenoid and a loop. [ABSTRACT FROM AUTHOR]

Brakes are essential parts of any system that involves motion. A few seconds are spent applying the brake, accumulating enough force to retard a system. In case of emergency stops, we need an efficient braking system that acts quickly and safely to avoid any mishaps. This work aims to develop a prototype of an instantaneous braking system, which can stop the motion of a rotating member. The operating principle of the device is the electromagnetic actuation of a solenoid. The actuation of a solenoid is simple and instantaneous. As a result, we could achieve immediate braking of a rotating member. [ABSTRACT FROM AUTHOR]

In this paper, a numerical simulation model of the flow field inside the diaphragm valve is established based on the k-ε turbulence model (where k represents the turbulent kinetic energy and ε represents the turbulent dissipation rate). The mass flow at the inlet and static pressure at the outlet are used as the numerical calculation conditions, and the accuracy of the model is verified through experiments. Based on this, the model is applied to analyze the internal flow characteristics and pressure field distribution of the valve body under different import flow rates (2.787-33.273 kg/s), and an accurate quantitative relationship between import flow rate and valve body head loss is established. The results show that: 1 the numerical simulation can better predict the head loss of the valve body under different flow conditions. When the inlet flow numbers are 5.546, 11.091 and 16.637 kg/s respectively, the relative errors between the experimental and numerical simulations are only -6.433%, 4.619%, and 7.264%. 3 With a constant inlet flow, the static pressure decreases from inlet to outlet in flow passage. Flow contraction caused by the blockage of the valve wall and the flow impinging on the diaphragm creates a large static pressure gradient in the valve body. 4 After water passes through the narrow flow channel on the valve wall, a cavitation zone and reflux phenomena occur downstream of the valve body. The cavitation zone appears mainly in the 1/3 fluid domain away from the outlet. As the inlet flow increases, the vortex in the downstream of the valve body intensifies and the reflux phenomenon becomes more significant, but the scope of the reflux zone does not increase significantly. 2 After verifying the accuracy of the model, this paper studies the valve body's internal flow characteristics and pressure field distribution under 18 different inlet flow conditions. The model establishes a relationship between the inlet mass flow Q and the head loss ΔP of the valve body. For Reynolds numbers from 37 927-21 5984 and inlet mass flow Q from 2.787-15.428 kg/s, the fitting equation is ΔP = 2 076.31Q - 7 567.49 (R² = 0.964). For Reynolds numbers from 240 097-467 009 and inlet mass flow Q from 17.141-33.273 kg/s, the fitting equation is ΔP = 5 688.02Q - 67 317.39(R² = 0.993). These results are useful for hydraulic calculations in irrigation systems. [ABSTRACT FROM AUTHOR]

This study explores a super-fast magnetic abrasive finishing (MAF) process for polishing the surface of an Inconel 625 bar workpiece for a hydrogen solenoid valve stem. The Inconel 625 bar was chosen to replace the existing STS 316 bar material, previously used for a hydrogen solenoid valve stem. The cylindrical surface of Inconel 625 bars was polished by a super-fast MAF process with high rotational speeds of 1000, 5000, 15,000, and 25,000 RPM and a super-strong magnetic field of 550 mT. The polishing characteristics of this process were evaluated according to the type of abrasives, rotational speeds of the workpiece and processing time. As a result, a super-smooth Inconel 625 bar was successfully achieved, with a surface roughness (Ra) reduced from 0.31 μm to 0.02 μm under the optimal conditions (15,000 RPM, CNT particles (0.04 μm), PCD diamond abrasive (1 μm), Fe (#200), 0.5 g of light oil, and 16 min of processing time). Also, the Ansys analysis results showed suitable strain, equivalent stress, and safety factor of the Inconel 625 bar. This confirmed that, after a super-fast MAF process, an Inconel 625 bar is feasible for application in Hydrogen (H2) tanks instead of a conventional STS 316 bar. [ABSTRACT FROM AUTHOR]

Solenoid connectors play important role in electronic stability system design, with the features of small size, low cost, fast response time and high reliability. The main production process challenge for solenoid connectors is the accurate detection of defects, which is closely related to safe driving. Both faultless and defective products have similar color and shape at the defect location, making proper inspection challenging. To address these issues, we proposed a defect detection model called PO-YOLOv5 to achieve accurate defect detection for solenoid connectors. First, an additional prediction head was added to enable the model to acquire more semantic information to detect larger-scale defective features. Second, we introduced dynamic convolution to learn complementary connections between the four dimensions of the convolution kernel by utilizing its multidimensional attention mechanism. Replacing conventional convolution with dynamic convolution enhances the detection accuracy of the model and reduces the inference time. Finally, we validated PO-YOLOv5 versus the state-of-the-art object detection methods on the same solenoid connectors dataset. Experiments revealed that our proposed approach exhibited higher accuracy. The mAP (mean Average Precision) result of PO-YOLOv5 was found to be about 90.1%. Compared with the original YOLOv5, PO-YOLOv5 exhibited improved precision by about 3%. [ABSTRACT FROM AUTHOR]

Under high-frequency operating conditions, the high-speed solenoid valve (HSV) experiences energy loss and heat generation, which significantly impacts its operational lifetime. Reducing the energy loss of an HSV without compromising its opening response characteristics poses a significant challenge. To address this issue, a finite element simulation model of an HSV coupled with a current feedback model is constructed to investigate the synergistic effects of dynamic response and energy loss. Prediction models for the opening response time, HSV driving energy, and Joule energy using a back propagation neural network (BPNN) are established. Furthermore, a multi-objective optimization study on the current driving strategy using a non-dominated sorting genetic algorithm II (NSGA-II) is conducted. After optimization, although there was a 6.24% increase in the opening response time, both HSV drive energy and Joule energy were significantly reduced by 15.67% and 22.49%, respectively. The proposed multi-objective optimization method for an HSV driving strategy holds great significance for improving its working durability. [ABSTRACT FROM AUTHOR]

This study reports fully 3D-printed, three-dimensional, soft magnetic-cored solenoids that generate three times the largest magnetic fields previously reported from 3D-printed solenoids. The devices are fabricated on a customised, multi-material 3D printer that can extrude both filaments and pellets. Three different kinds of materials are employed to manufacture the reported soft magnetic-cored solenoids: pure PLA (dielectric portions), PLA doped with copper particles (electrically conductive structures), and nylon or PLA doped with metallic particles (soft magnetic cores). Via manufacturing optimisation, the reported devices are 33% smaller and can withstand about twice the current, generating three times more magnetic field. The 3D-printed solenoids generate Gauss-level magnetic fields while drawing tens-of-milliamps currents and can be readily used to implement fully 3D-printed induction sensors. The results of this work extend the state of the art in 3D-printed electronics, enabling the creation of more complex and capable solenoids for in-situ manufactured and in-space manufactured electromagnetic systems. [ABSTRACT FROM AUTHOR]

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In this study, the performance of a long-stroke moving-iron proportional solenoid actuator (MPSA) was improved by combining numerical simulations and experiments. A finite element model of the MPSA was developed; its maximum and mean relative absolute errors of electromagnetic force were 4.3% and 2.3%, respectively, under typical work conditions. Seven design parameters including the cone angle, cone length, depth of the inner hole of the coil skeleton, cone width of the armature, inner cone diameter, and initial position of the moving-iron core were selected for developing the model, and the coefficient of the variation in electromagnetic force, nominal acceleration, 95% of the maximum stable output electromagnetic force, and corresponding response time were used as the performance indicators. The constraint relation between each performance indicator and the influence of each design parameter on the performance indicators were revealed using the uniform Latin hypercube experiment design, correlation analysis, and the main effect analysis method. A multi-objective optimization mathematical model of the MPSA was developed by combining traditional surrogate and machine learning models. The Pareto solution set was obtained using the nondominated sorting genetic algorithm II (NSGA-II), and three decision schemes with different attitudes were determined using the Hurwicz multi-criteria decision-making method. The results showed that a strong contradiction exists among the 95% of the maximum stable output electromagnetic force and its corresponding response time and the coefficient of the variation in electromagnetic force. The cone angle considerably influenced the performance indicators. Compared with the initial design, the coefficient of the variation in electromagnetic force was reduced by 54.08% for the positive decision, the corresponding response time was shortened by 15.65% for the critical decision, and the corresponding acceleration was enhanced by 10.32% for the passive decision. Thus, the overall performance of the long-stroke MPSA effectively improved. [ABSTRACT FROM AUTHOR]

Drastic changes in the random load of an electromechanical system bring about a reliability problem for the proportional solenoid valve based on a thermal effect. In order to accurately and effectively express the thermal load of a proportional solenoid valve under random load conditions and to meet the requirements of online acquisition, adaptive anomaly detection, and the missing substitution of thermal load data, a thermal load prediction model based on the Kalman filter algorithm is proposed. Taking the compound operation process of an excavator as the object and based on the field testing of an excavator and the independent testing experiment of a proportional solenoid valve in a non-installed state, a method of obtaining historical samples of the proportional solenoid valve's power and thermal load is given. The k-means clustering algorithm is used to cluster the historical samples of the power and thermal load corresponding to the working posture of a multi-tool excavator. The Grubbs criterion is used to eliminate the outliers in the clustering samples, and unbiased estimation is performed on the clustering samples to obtain the prediction model. The results show that the cross-validation of the sample data under the specific sample characteristics of the thermal load model was carried out. Compared with other methods, the prediction accuracy of the thermal load model based on the Kalman filter is higher, the adaptability is strong, and the maximum prediction deviation percentage is stable within 5%. This study has value as a reference for random cycle thermal load analyses of low-frequency electromechanical products. [ABSTRACT FROM AUTHOR]

A novel micro-solenoid resonator has been designed, simulated, and measured. The solenoid core consisted of a DuroidTM circuit board with a relative permittivity of 2.2. The resonator design incorporated four embedded copper vias with a radius of 125 µm and three surface conductors to form a rectangular coil. A pitch size of 250 µm was used for a 3.02 mm thick substrate. To enhance the resonator's performance at higher frequencies, a capacitance was introduced in series through the via. This additional capacitor effectively couples the inductance, resistance, and stray capacitance. The optimization of the quality factor was investigated through pole transfer analysis, resulting in an increased resonance frequency of 12.25 GHz and an elevated Q-factor of 306. Moreover, besides its very high Q-factor, this resonator offers a simplified design and easy integration. An analytical lumped circuit model was employed to investigate the design, and the measured S-parameters closely matched the analytical model and electromagnetic simulation results. The tuned resonator exhibited a superior quality factor compared to other micro-resonators. [ABSTRACT FROM AUTHOR]

Compared with electroplating, liquid casting enables the rapid formation of a three-dimensional solenoid coil with a narrower line width and greater thickness, which proves advantageous in enhancing the comprehensive performance of the micro-electromechanical system (MEMS) fluxgate sensor. For this reason, a MEMS fluxgate sensor based on liquid casting with a closed-loop Fe-based amorphous alloy core is proposed. Based on the process parameters of liquid casting, the structure of the MEMS fluxgate sensor was designed. Utilizing MagNet to build the simulation model, the optimal excitation conditions and sensitivity were obtained. According to the simulation model, a highly sensitive MEMS fluxgate sensor based on liquid casting was fabricated. The resulting sensor exhibits a sensitivity of 2847 V/T, a noise of 306 pT/√Hz@1 Hz, a bandwidth of DC-10.5 kHz, and a power consumption of 43.9 mW, which shows high sensitivity and low power consumption compared with other MEMS fluxgates in similar size. [ABSTRACT FROM AUTHOR]

Superconducting electron cyclotron resonance ion sources (ECRISs) using NbTi coils and optimized for 28 GHz resonant heating have been successfully operated for almost two decades. Moving to higher heating frequencies requires increased magnetic fields, but traditional racetrack-and-solenoid ECRIS structures are at their limit using NbTi. Rather than moving to a superconductor untested in this field, the Mixed Axial and Radial field System (MARS) being developed at Lawrence Berkeley National Laboratory employs a novel closed-loop-coil design that more efficiently utilizes conductor fields and will allow the use of NbTi in a next-generation, 45 GHz ECRIS. This article presents the design of the shell-based support structure central to the MARS-D magnet design, as well as structural analysis of its components and optimization of pre-load parameters that will guarantee its successful operation.

Like all authors, the romanian Mircea Cărtărescu creates his own ethos, not only in his original literary field, but in all the fields to which his work is translated. Unlike the «brand identity» of any other commercial product, the figure of the writer is a flexible and dynamic construction --within its reiteration--, which is adapting to a «previous ethos» in constant evolution, according to the increase or loss of symbolic and social capital. Self-image is often communicated through implicit or explicit «career narratives», in which the literary author reacts to a «brand image», perceived as unsatisfactory or defective. This study attempts to highlight both significant nodes in the network of Cărtărescu's ethos and the rhetorical resources used to communicate them. For this purpose, the «career narratives» expressed during two face-to-face paratextual activities, held on Spanish soil were analysed: the first, when the author in question was still an emerging writer in Spain, and the second, right after the remarkable success of his novel Solenoid. [ABSTRACT FROM AUTHOR]

Haloscopes, microwave resonant cavities utilized in detecting dark matter axions within powerful static magnetic fields, are pivotal in modern astrophysical research. This paper delves into the realm of cylindrical geometries, investigating techniques to augment volume and enhance compatibility with dipole or solenoid magnets. The study explores volume constraints in two categories of haloscope designs: those reliant on single cavities and those employing multicavities. In both categories, strategies to increase the expanse of elongated structures are elucidated. For multicavities, the optimization of space within magnets is explored through 1D configurations. Three subcavity stacking approaches are investigated, while the foray into 2D and 3D geometries lays the groundwork for future topological developments. The results underscore the efficacy of these methods, revealing substantial room for progress in cylindrical haloscope design. Notably, an elongated single cavity design attains a three-order magnitude increase in volume compared to a WC-109 standard waveguide-based single cavity. Diverse prototypes featuring single cavities, 1D, 2D, and 3D multicavities highlight the feasibility of leveraging these geometries to magnify the volume of tangible haloscope implementations. [ABSTRACT FROM AUTHOR]

Problem. The flow of currents in the conductive elements of electrical systems is accompanied by the excitation of electromagnetic fields and the occurrence of induced currents. The excitation of the induced signals, in turn, leads to a change in the parameters of the actual exciting currents. The purpose of the work is to obtain analytical expressions for the quantitative analysis of the results of the mutual influence of the exciting and induced currents and to calculate their ratio depending on the geometric characteristics of the inductor systems. Methodology. The analysis of the processes of mutual influence is carried out on the example of a widespread inductor system, where a flat circular solenoid is placed above the surface of a massive conductor. Analytical expressions for eddy currents excited in a massive conductor and numerical estimates of the effect of induced currents on exciting currents in a solenoid are obtained. Results. It is shown that the influence of the induced current on the current in the solenoid is very significant at small distances between the solenoid and the surface of the massive solenoid. It has been found that an increase in the width of the solenoid winding leads to a significant increase in the influence of the induced current on the excitation current in the solenoid. It is shown that the inductance of the «circular solenoid - massive conductor» system drops with a decrease in the distance between the solenoid and the massive conductor and an increase in the radial dimensions of the solenoid, which requires an increase in the amplitude of the exciting current to maintain a given value of the magnetic flux in the system. Originality. The scientific novelty of this work lies in the proposal of an analytical approach and obtaining numerical estimates of the mutual influence of conductors with exciting and induced currents. Practical value. Estimates of the mutual influence of conductors with currents are of interest for the practice of designing structures of electrical systems for various purposes. Very promising in the direction further research is seen as carrying out experiments with measurements of the quantitative characteristics of the mutual influence of exciting and induced currents in various designs of electrical systems. [ABSTRACT FROM AUTHOR]

Solenoids, ubiquitous in electrical engineering applications, are devices formed from a coil of wire that use electric current to produce a magnetic field. In contrast to typical electrical engineering applications that pertain to their magnetic field, of interest here is their use as actuators by studying their mechanical deformation. An analytically tractable model of parallel, coaxial circular rings is used to find the solenoid's axial deformation when subjected to a combined electrical (current) and mechanical (axial force) loading. Both finite and infinite solenoids are considered and their equilibrium configurations as well as their stability are investigated as functions of their geometry and applied current intensity. [ABSTRACT FROM AUTHOR]

To alleviate the Eddy effect of the high-speed solenoid valve (HSV) and improve its dynamic response speed, a novel HSV with a composite iron core is presented. The time-step finite element method is used to establish and verify the numerical simulation of HSV coupling multiple physical fields. Then, the Eddy effect and dynamic response characteristics of the conventional and composite HSVs are further compared and analyzed. The results showed that the Eddy current loss in the main pole was the largest for the conventional HSV, accounting for 72.5% and 64.4% in the actuation and release processes, respectively. It was found that the Eddy effect of the composite HSV was obviously weakened, and the total Eddy current losses in the actuation and release processes were reduced by 58.8% and 38.7%, respectively. Meanwhile, the actuation response time and release response time of the composite HSV were shortened by 15.6% and 18.5%, respectively. In addition, increasing the peak voltage further shortened the actuation response time of the composite HSV, but had no significant effect on the response time of the conventional HSV. [ABSTRACT FROM AUTHOR]

In this letter, a novel 3-D heterogeneous solenoid inductor with high inductance value is proposed. By adding planar spiral structure at the ends of through-silicon vias (TSVs) of typical 3-D solenoid inductor, the heterogeneous solenoid is formed. The total inductance is increased by more than 41% compared with that of typical solenoid inductor of the same size. Additionally, an accurate analytical model of the inductor is established considering all the factors including angle and offset. Q3D simulation results verified the accuracy of the model, and the percentage error is less than 5.38%. This work provides an important reference for inductor designers to quickly estimate inductance value, configuration, and layout area. [ABSTRACT FROM AUTHOR]

The hydraulic solenoid valve is an essential electromechanical component used in various industries to control the flow rate, pressure, and direction of hydraulic fluid. However, these valves can fail due to factors like electrical issues, mechanical wear, contamination, seal failure, or improper assembly; these failures can lead to system downtime and safety risks. To address hydraulic solenoid valve failure, and its related impacts, this study aimed to develop a nondestructive diagnostic technology for rapid and accurate diagnosis of valve failures. The proposed approach is based on a data-driven model that uses voltage and current signals measured from normal and faulty valve samples. The algorithm utilizes a convolutional autoencoder and hypersphere-based clustering of the latent variables. This clustering approach helps to identify patterns and categorize the samples into distinct groups, normal and faulty. By clustering the data into groups of hyperspheres, the algorithm identifies the specific fault type, including both known and potentially new fault types. The proposed diagnostic model successfully achieved an accuracy rate of 98% in classifying the measurement data, which were augmented with white noise across seven distinct fault modes. This high accuracy demonstrates the effectiveness of the proposed diagnosis method for accurate and prompt identification of faults present in actual hydraulic solenoid valves. [ABSTRACT FROM AUTHOR]

Haloscopes are resonant cavities that serve as detectors of dark matter axions when they are immersed in a strong static magnetic field. In order to increase the volume and improve space compatibility with dipole or solenoid magnets for axion searches, various haloscope design techniques for rectangular geometries are discussed in this study. The volume limits of two types of haloscopes are explored: those based on single cavities and those based on multicavities. In both cases, possibilities for increasing the volume of long and/or tall structures are presented. For multicavities, 1D geometries are explored to optimise the space in the magnets. Also, 2D and 3D geometries are introduced as a first step in laying the foundations for the development of these kinds of topologies. The results prove the usefulness of the developed methods, evidencing the ample room for improvement in rectangular haloscope designs nowadays. A factor of three orders of magnitude improvement in volume compared with a single cavity based on the WR-90 standard waveguide is obtained with the design of a long and tall single cavity. Similar procedures have been applied for long and tall multicavities. Experimental measurements are shown for prototypes based on tall multicavities and 2D structures, demonstrating the feasibility of using these types of geometries to increase the volume of real haloscopes. [ABSTRACT FROM AUTHOR]

The mobility of today and tomorrow is characterized by technological change and new challenges in drive concepts such as electric or hydrogen vehicles. Abolishing conventional combustion engines creates even more need for switching or valve technology in mobility systems. For switching and controlling purposes, solenoids are used in large numbers and in a wide variety of applications, thus making a significant contribution to the overall success of the energy transition, and not only in the automotive sector. Despite their long existence, continued research is being carried out on solenoids involving new materials and actuator concepts. Great interest is focused on providing an adjustable force–displacement characteristic while simultaneously reducing the noise during switching. At IKFF, research is being conducted on hybrid electromagnets in the border area of switching and holding solenoids. This paper aims to present the major advantages of this hybrid drive concept based on an electromagnetic FEA simulation study of two drive concepts and specially developed and characterized prototypes with magnetic shape memory (MSM) alloys. The concepts differ in the spatial orientation of the MSM sticks to generate an active stroke of the plunger, which contributes to a beneficial force–displacement characteristic and lower power consumption while minimizing switching noise. [ABSTRACT FROM AUTHOR]

Inductive power transfer (IPT) technology is a promising solution for charging the electric vehicles (EVs) by enabling an EV to charge its energy storage system (battery) without any connecting wires through magnetic coupling. This paper proposes a new receiver design named Hollow Solenoid receiver that is compatible with the standard double-D transmitter defined by the SAE J2954 standard. A deep design analysis for the proposed Hollow Solenoid receiver is presented to define the optimum design parameters for coil (inductances, number of turns, dimensions, wires, etc.) and ferrite core (dimensions, number, arrangement, etc.). Several WPT3 (11.1kVA) solenoid receiver (SR) designs were presented and analyzed based on efficiency, weight, size, volume, and cost. The performance of the proposed SR was compared with the global Double-D receiver (DDR) presented by the SAE J2954 standard under different lateral and rotational alignment and loading conditions considering coupling factor, transmission power and efficiency, and stray electromagnetic fields (EMFs). The entire IPT system including coils, compensation network, power converters, controls, and battery load was modeled and analyzed for both SR and DDR coils. The results reveal that the proposed SR is compatible with the global DD transmitter at different alignment and loading conditions and is able to transmit the desired power (11 kW) at an efficiency > 85%. Hollow SR design shows the highest efficiency and lowest size, weight, and cost compared to DDR and other designs. [ABSTRACT FROM AUTHOR]

The International Thermonuclear Experimental Reactor (ITER) is a cutting-edge project that aims to develop a sustainable energy source by harnessing the power of nuclear fusion. One of the key challenges in the development of the ITER is the complex electrical grid that is required to support its operations. To address this challenge, a digital twin (DT) of the Central Solenoid (CS) Converter Power Supply grid has to be developed, and real-time simulation strategies have been proposed to monitor and study the performance of the ITER grid. Real-time simulation strategies allow for continuous feedback on the performance of the grid, enabling the quick identification and resolution of issues. However, it is not always possible to perform real-time simulation easily in a real-time simulator; therefore, specific strategies have to be implemented in the DT. This paper focuses on decoupling lines and explicit partitioning as solutions to allow the real-time simulation of the CS Converter Power Supply grid with two converter units (CUs), as required by the ITER Organization (IO). As will be shown later in this article, the proposed approach is progressive and applicable to a more complex grid with multiple CUs. The results concerning the proposed strategies will be analyzed and discussed in terms of real-time performance. [ABSTRACT FROM AUTHOR]

In this study, the influence of an axial-electromagnetic field treatment device (AEFTD) with a solenoid structure using different electromagnetic frequencies on calcium carbonate (CaCO3) crystallization fouling on the tube side of a shell-and-tube heat exchanger was investigated. The experimental results indicated that the application of the AEFTD could effectively reduce fouling resistance and decelerate the growth rate of CaCO3 fouling. The opposite trend between fouling resistance and the outlet temperature of an experimental fluid indicated that the application of the AEFTD could enhance heat transfer. Meanwhile, the crystal morphologies of the fouling samples were analyzed by means of scanning electron microscopy (SEM). The axial-electromagnetic field favored the formation of vaterite as opposed to calcite. Non-adhesive vaterite did not easily aggregate into clusters and was suspended in bulk to form muddy fouling that could be carried away by turbulent flow. Furthermore, the anti-fouling mechanism of the axial-electromagnetic field is discussed in detail. The anti-fouling effect of the AEFTD on CaCO3 fouling exhibited extreme characteristics in this study. Therefore, the effectiveness of the AEFTD is contingent upon the selection of the electromagnetic parameters. [ABSTRACT FROM AUTHOR]

Efficient fuel injection and exhaust gas cleaning systems are needed to promote the development of high-performance internal combustion systems and decrease greenhouse gas emissions. Electronically controlled injection systems enable nearly unlimited control over system components whose operation is limited by the inertia of moving parts and other physical phenomena. In the present study, a novel technology for manufacturing magnetic cores was proposed to improve the performance of solenoid injectors in Diesel engines. The conducted simulations and experiments revealed that the developed technology can increase the speed of solenoid injectors. In the proposed solution, the fuel dose was split to effectively control the injection process and improve engine performance. [ABSTRACT FROM AUTHOR]