Search

In order to study the air gap magnetic field distribution and torque of axial-flux solid magnetic couplers with 9 pairs of permanent magnets, a layer model is firstly introduced, which divides the couplers into conductive and non-conductive areas. The two-dimensional magnetic scalar potential method is derived to solve the magnetic field strength in conductive areas and the magnetic scalar potential in non-conductive areas. Carter coefficient is introduced to correct the 3D end effects, and the formula of air gap flux density and torque is derived. Then， the distribution of 3D air gap magnetic field, eddy current and the influence of different working parameters on the characteristics of the torque are obtained by the finite element simulation software. Finally, a measure system of three-dimensional magnetic field and the magnetic drive experimental platform are built to measure the 3D air gap magnetic field and the torque. The experimental results are in good agreement with the results of theoretical calculation and the simulation analysis, which shows that the formula of the air gap flux density and the torque have high accuracy and can be used as a reference for further research on the transmission characteristics of eddy-current magnetic couplers.

Aiming at the speed regulation characteristics of slotted-type eddy-current couplers, the expression of the induced magnetic field generated by the induced eddy current is derived by using Ampère's law and the induced magnetic field is introduced into the equivalent magnetic circuit model. Then, the calculation formula of electromagnetic torque is derived in combination with Kirchhoff's law. The electromagnetic torque formula is combined with the expression of constant torque load and quadratic rate load respectively, and the theoretical formula of the speed regulation relationship under corresponding load conditions is obtained. The 3D finite element simulation and experiment are used to verify the proposed theoretical model of speed regulation. It is found that the proposed theoretical model has good accuracy in the case of small air gap length.

In order to study the transmission performance of slotted-type eddy-current couplers with radial misalignment, based on the theory of the equivalent magnetic charge theory, the copper which cuts the magnetic field line in motion is equivalent to permanent magnet. Combining with Coulomb's law, a calculation model of output torque is established in this study. The analysis of magnetic flux density, copper loss and output torque of couplers are all simulated by finite element software, and the maximum allowable value of radial misalignment is obtained. The results show that with the increase of radial misalignment, the induced magnetic field decreases during operation, which results in the increase of the magnetic flux density, the decrease of the copper loss and the torque, and the fluctuations of the copper loss and the output torque changing with time become more and more obvious. When the radial misalignment is less than 6 mm, the torque generated by the couplers can almost be remained accurately and the fluctuation of the torque is relatively stable.

In order to solve the problem of calculating the air gap magnetic field and torque of slotted-type magnetic couplers, a subdomain analysis model is introduced. The magnetic couplers are divided into five regions along the axis, the boundary equations are established at the interfaces of each region. According to the alternating arrangement characteristics of yoke teeth and the conductor and the vector magnetic potential formulas in yoke teeth and the copper conductor disk are deduced respectively. Due to the end effect, Schwarz-Christoffel mapping is used to modify the coefficient of the flux density at the end face of the cogging. On the basis of obtaining the vector magnetic potential of the yoke iron and conductor respectively, the formulas of the air gap magnetic field and electromagnetic torque are deduced. The structure parameters of the slotted-type magnetic couplers are substituted into the theoretical model to calculate the axial air-gap magnetic field distribution and mechanical characteristic curves. By comparing the results with those obtained by finite element simulation, the accuracy of the theoretical model is verified and the cause of the error is analyzed.

Microcellular injection moulding is an important injection moulding technique to create foaming plastic parts. However, there are no consistent conclusions on the impact of processing parameters on the cell morphology of microcellular injection moulded parts. This paper investigates the influence of the main processing parameters, such as melt temperature, mould temperature, injection pressure, flow rate, shot volume and gas dosage amount, on the average cell size and weight reduction of a talc-reinforced polypropylene square part (165 mm × 165 mm × 3.2 mm), using the commercial software Moldex 3D. The effect of each parameter is investigated considering a range of values and the simulation results were compared with published experimental results. The differences between numerical and experimental trends are discussed. [ABSTRACT FROM AUTHOR]

The last decade has seen a flurry of research on all-pairs-similarity-search (or similarity joins) for text, DNA and a handful of other datatypes, and these systems have been applied to many diverse data mining problems. However, there has been surprisingly little progress made on similarity joins for time series subsequences. The lack of progress probably stems from the daunting nature of the problem. For even modest sized datasets the obvious nested-loop algorithm can take months, and the typical speed-up techniques in this domain (i.e., indexing, lower-bounding, triangular-inequality pruning and early abandoning) at best produce only one or two orders of magnitude speedup. In this work we introduce a novel scalable algorithm for time series subsequence all-pairs-similarity-search. For exceptionally large datasets, the algorithm can be trivially cast as an anytime algorithm and produce high-quality approximate solutions in reasonable time and/or be accelerated by a trivial porting to a GPU framework. The exact similarity join algorithm computes the answer to the time series motif and time series discord problem as a side-effect, and our algorithm incidentally provides the fastest known algorithm for both these extensively-studied problems. We demonstrate the utility of our ideas for many time series data mining problems, including motif discovery, novelty discovery, shapelet discovery, semantic segmentation, density estimation, and contrast set mining. Moreover, we demonstrate the utility of our ideas on domains as diverse as seismology, music processing, bioinformatics, human activity monitoring, electrical power-demand monitoring and medicine. [ABSTRACT FROM AUTHOR]

Ferroptosis represents an iron - and lipid peroxidation (LPO)-mediated form of regulated cell death (RCD). Recent evidence strongly suggests the involvement of ferroptosis in various neurodegenerative diseases (NDs), particularly Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS), among others. The treatment of ferroptosis poses both opportunities and challenges in the context of ND. This review provides a comprehensive overview of characteristic features, induction and inhibition of ferroptosis, highlighting the ferroptosis inhibitor and the underlying mechanisms responsible for its occurrence. Moreover, the review explores how these mechanisms contribute to the pathogenesis and progression of major neurodegenerative disorders. Additionally, it presents novel insights into the role of ferroptosis in ND and summarizes recent advancements in the development of therapeutic approaches targeting ferroptosis. These insights and advancements hold potential to guide future strategies aimed at effectively managing these debilitating medical conditions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Fei and Ding.)