Hemodialysis catheter-related infection caused by Pannonibacter phragmitetus: a rare case report in China

Pannonibacter phragmitetus (P. phragmitetus) is rarely related with human disease. We reported a case of catheter-related infection caused by P. phragmitetus in a 68-year-old woman on hemodialysis. The patient developed recurrent fever during hemodialysis and blood cultures were positive for P. phragmitetus. The patient’s body temperature returned to normal after intravenous cefoperazone/sulbactam treatment, and the hemodialysis catheter was locked with gentamicin and urokinase. The potential anti-infective treatment against P. phragmitetus was discussed

Research on an Axial Flux PMSM with Radially Sliding Permanent Magnets

Axial flux permanent-magnet synchronous machines (PMSMs) are very suitable candidates for the power train of electric vehicles (EVs) due to high power density and high efficiency. This paper researches an axial flux PMSM with radially sliding permanent magnets (PMs) to fulfill field-weakening control. The field weakening principle and the structure of this kind of axial flux PMSM by mechanical method of sliding PMs are proposed and analyzed. The influences of radially sliding PMs on magnetic flux density distribution, inductance, flux linkage and torque are analyzed and discussed based on 3D finite element method (FEM). The field weakening capabilities by mechanical method and electrical method are compared. The field weakening capability of the machine can be much improved by the optimized combination of the two methods, which is very satisfying for EV drive application. The forces on the PMs are analyzed and calculated. The hysteretic characteristics caused by the friction of the PMs are investigated, which provide useful reference for designing this kind of machine

Torque Ripple Reduction of a Novel Modular Arc-Linear Flux-Switching Permanent-Magnet Motor with Rotor Step Skewing

A novel modular arc-linear flux-switching permanent-magnet motor (MAL-FSPM) used for scanning system instead of reduction gearboxes and kinematic mechanisms is proposed and researched in this paper by the finite element method (FEM). The MAL-FSPM combines characteristics of flux-switching permanent-magnet motor and linear motor and can realize the direct driving and limited angular movement. Structure and operation principle of the MAL-FSPM are analyzed. Cogging torque model of the MAL-FSPM is established. The characteristics of cogging torque and torque ripple are investigated for: (1) distance (dend) between left end of rotor and left end of stator is more than two rotor tooth pitch (τp); and (2) dend is less than two rotor tooth pitch. Cogging torque is an important component of torque ripple and the period ratio of the cogging torque to the back electromotive force (EMF) equals one for the MAL-FSPM before optimization. In order to reduce the torque ripple as much as possible and affect the back EMF as little as possible, influence of period ratio of cogging torque to back EMF on rotor step skewing is investigated. Rotor tooth width and stator slot open width are optimized to increase the period ratio of cogging torque to back EMF. After the optimization, torque ripple is decreased by 79.8% for dend > τp and torque ripple is decreased by 49.7% for dend < τp. Finally, 3D FEM model is established to verify the 2D results

Safe, Efficient, and Comfortable Autonomous Driving Based on Cooperative Vehicle Infrastructure System

Traffic crashes, heavy congestion, and discomfort often occur on rough pavements due to human drivers’ imperfect decision-making for vehicle control. Autonomous vehicles (AVs) will flood onto urban roads to replace human drivers and improve driving performance in the near future. With the development of the cooperative vehicle infrastructure system (CVIS), multi-source road and traffic information can be collected by onboard or roadside sensors and integrated into a cloud. The information is updated and used for decision-making in real-time. This study proposes an intelligent speed control approach for AVs in CVISs using deep reinforcement learning (DRL) to improve safety, efficiency, and ride comfort. First, the irregular and fluctuating road profiles of rough pavements are represented by maximum comfortable speeds on segments via vertical comfort evaluation. A DRL-based speed control model is then designed to learn safe, efficient, and comfortable car-following behavior based on road and traffic information. Specifically, the model is trained and tested in a stochastic environment using data sampled from 1341 car-following events collected in California and 110 rough pavements detected in Shanghai. The experimental results show that the DRL-based speed control model can improve computational efficiency, driving efficiency, longitudinal comfort, and vertical comfort in cars by 93.47%, 26.99%, 58.33%, and 6.05%, respectively, compared to a model predictive control-based adaptive cruise control. The results indicate that the proposed intelligent speed control approach for AVs is effective on rough pavements and has excellent potential for practical application

Investigation of Electromagnetic, Thermal and Mechanical Characteristics of a Five-Phase Dual-Rotor Permanent-Magnet Synchronous Motor

This paper investigates of a kind of five-phase dual-rotor permanent-magnet synchronous motor (DRPMSM), which contains dual rotors and a single stator. This kind of motor has the potential advantages of high power density, high reliability and high efficiency, which make it more appropriate for using in electric vehicles (EVs). In order to evaluate the most suitable power level for this kind of structure, the electromagnetic, the thermal and the mechanical characteristics are investigated in this paper. The length to diameter ratio of motors is researched to obtain the highest power density and then the optimum ratio is obtained. Based on the optimum ratio, the thermal characteristics are researched under natural condition and forced-air cooling condition with different wind speeds. In addition, the mechanical characteristics are analyzed under no-load and different loads conditions, respectively. All of the results are analyzed by two-dimension (2-D) and three-dimension (3-D) finite element method (FEM) simulation, which provide a good reference to select suitable power level for this kind of motor structure. Finally, a DRPMSM prototype is manufactured and tested. The experimental results effectively verify the FEM results

Research on the Torque and Back EMF Performance of a High Speed PMSM Used for Flywheel Energy Storage

Due to advantages such as high energy density, high power density, rapid charge and discharge, high cyclic-life, and environmentally friendly, flywheel energy storage systems (FESs) are widely used in various fields. However, the performance of FES systems depends on the performance of a high speed machine, therefore, the design and optimization of a high efficiency and high power density machine are very crucial to improve the performance of the whole FES system. In this paper, a high speed permanent-magnet synchronous machine (PMSM) is researched. Considering the requirement of low torque ripple in low speed and loss caused by back electromotive force (EMF) harmonics, the electromagnetic performance is improved from points of view of slot/pole matching, magnetic-pole embrace with the finite element method (FEM). Furthermore, the magnetic-pole eccentricity, the slot opening, the thickness of PM and air-gap length are also optimized with Taguchi method. The electromagnetic performance, such as torque ripple, cogging torque, average torque and back EMF wave are much improved after optimization. Finally, experiments are carried out to verify the calculated results

Comprehensive Evaluation of Wheat Varieties in Southern Shandong Province by DTOPSIS Based on Entropy Weighting

[Objectives] To screen a new wheat variety suitable for planting in southern Shandong Province. [Methods] The DTOPSIS based on entropy weighting was used to comprehensively evaluate 9 traits of 19 wheat varieties planted in southern Shandong Province. [Results] The weight of each indicator from low to high was growth period < yield < bulk density < plant height < effective panicle < basic seedling < 1 000-grain weight < heading rate < number of grains per panicle. The Ci value of 6 varieties were greater than 0.5, specifically, 0.922 1 for Shannong HH126, 0.868 for DK171, 0.851 5 for Hemai 179, 0.719 6 for Feida 6, 0.696 7 for Jinlai 36 and 0.523 2 for Yannong 301. [Conclusions] The comprehensive traits of these six wheat varieties are good, and they are suitable for planting in southern Shandong Province