According to researching the spin traveling wave pump, the relationship of the characteristics of magnetic fluid and the press is investigated under the spin magnetic field by the theory method. The ...relationship of moving, magnetic field and press is investigated by the decoupled computation between the magnetic field and force. The dynamic equations are analyzed under the traveling wave magnetic field. The velocity equation, the spin velocity equation and flux equation per unit time are also analyzed. The method is scientificity and rationality by the testing. The distributing shape of magnetic fluid in the pump is affected by the adding magnetic field under the spin magnetic field when the magnetic fluid is filled in the pump. At the same time, the adding magnetic field is affected by magnetic particles of magnetic fluid. The magnetic fluid can be moved by the effect of the adding magnetic field in the pump. The flux of magnetic fluid increases with the magnetic field.
According to the analysis of problems existed in grey evaluation model of operation information system assessment, Based on the rough set theory, a grey comprehensive evaluation model Based on rough ...set attribute reduction. This paper discusses the evaluation process of the model, the multi-level and the establishment of a operation information system survivability evaluation index system, has carried on the example analysis combining the actual operation information system. The results show that, the rough set theory and the grey comprehensive evaluation model Based on multiple levels, in the premise of not affecting the key information, to maximize the elimination of redundant information, eliminate dependency relationships between indexes in whole or in part, reduces the influence of subjective factors in evaluation, improve the effectiveness and objectivity refers to essential information system evaluation conclusion. Provides the theory basis for the actual use of scientific evaluation information command system.
The adding magnetic field affects the distributing shape of magnetic fluid. According to the magnetic particles of the magnetic fluid, the adding magnetic fluid is affected. The decoupled question ...between the magnetic field and force is solved by the Boundary-Step by Step-Hand and Hand Iterative method. The stream of magnetic fluid is produced by the traveling wave magnetic field. The velocity of the magnetic fluid can increased with the increasing saturation magnetization and magnetic field. The difference press is max in the center line of pump, and the difference is min in the edge of pump. The acceleration is max in the center line of pump, and the acceleration is min in the edge of pump. The velocity of center line is max, and the edge is min with the same time interval. The velocity of magnetic fluid reduces from the center line to edge.
The decoupled question of magnetic fluid and magnetic field is investigated by the Boundary-Step by Step Hand Method. The magnetic field intensity and the saturation magnetization of magnetic fluid ...affect driving capacity of magnetic fluid traveling wave pump directly. The driving capacity increases increasing of the magnetic field intensity and the saturation magnetization of magnetic fluid. The viscosity of the magnetic fluid affects the driving capacity too. The viscosity of magnetic fluid can change when the magnetic field changes. The viscosity increases when magnetic field increases. When magnetization of magnetic fluid reaches saturation, the viscosity changes tardily. The driving capacity reduces with the increasing of the viscosity. The shape of the magnetic pole affects the driving capacity. The magnetic induction in the pump can be changed with the changing on the shape of magnetic pole. The driving capacity is max when the pole angle is 450.
Roller washers under BLDCM direct driving are spreading more widely in modern families. The clothes to be washed in the washer will generate an impact to speed and torque of the driving system. In ...this paper, mathematical models were set up to analyze the four stages of the wet laundry load in washing mode, and load torque of the wet laundry load were obtained. Results of experimental tests proved correctness of the simulation analysis, which can be used for reference of precise control of roller washers.
Aiming at realizing the performance of high torque, low speed and high reliability for the Permanent Magnet Synchronous Machine (PMSM), a superpower multi-unit PMSM was designed, which had five units ...and each unit including an independent three-phase star-connection windings and an independent driver device. When the multi-unit PMSM was running under normal conditions, its operation was very similar to the general three-phase PMSM and even it can be regarded as general three-phase PMSM. It was different from the normal three-phase PMSM, when only part unit motors can be normally operated and the others were under the fault conditions. Due to the different magnetic conductivity of three-phase windings mutual inductances, the mutual inductance of the same unit was not symmetric in these unit motors. Furthermore, the electrical torque ripple would be increased due to the asymmetric mutual inductances, when part units were operating. However, there was a strong rule which can be estimated through the relationship of the running units' space position and quantity. In one word, the torque ripple is decreased using the correct rule when the whole unit motors are not normal working. In addition, the torque ripple of multi-unit PMSM is also restrained according to the analysis results.
This paper presents an approach for enhancing the thrust force of a tubular transverse flux permanent magnet linear machine (TFPMLM) which has been developed for electromagnetic applications. It is ...shown that by introducing auxiliary cores to suppress the leakage flux, the thrust force of the tubular TFPMLM has been significantly enhanced, by ~130% under the same volumetric constraints. The effectiveness of the proposed technique is validated by extensive 3-dimensional finite element computations.
Background. Adverse maternal environments may predispose the offspring to metabolic syndrome in adulthoods, but the underlying mechanism has not been fully understood. Methods. Maternal hyperglycemia ...was induced by streptozotocin (STZ) injection while control (CON) rats received citrate buffer. Litters were adjusted to eight pups per dam and then weaned to standard diet. Since 13 weeks old, a subset of offspring from STZ and CON dams were switched to high fat diet (HFD) for another 13 weeks. Glucose and insulin tolerance tests (GTT and ITT) and insulin secretion assay were performed; serum levels of lipids and leptin were measured. Hepatic fat accumulation and islet area were evaluated through haematoxylin and eosin staining. Results. STZ offspring exhibited lower survival rate, lower birth weights, and growth inhibition which persisted throughout the study. STZ offspring on HFD showed more severe impairment in GTT and ITT, and more profound hepatic steatosis and more severe hyperlipidemia compared with CON-HFD rats. Conclusions. Offspring from diabetic dams would be prone to exhibit low birth weight and postnatal growth inhibition, but could maintain normal glucose tolerance and insulin sensitivity. HFD accelerates development of insulin resistance in the offspring of diabetic dams mainly via a compensatory response of islets.
This paper investigates the characteristics of the unbalanced magnetic force and the thrust force in asymmetric 6-slot/6-pole transverse flux permanent magnet linear machine with diametrically ...asymmetric magnets by using the three-dimensional finite element method. In order to eliminate the unbalanced magnetic force, a new topology, i.e., symmetric magnets of a 6-slot/6-pole TFPMLM is proposed. Furthermore, the analysis and comparison results of two proposed machine are illuminated in order to improve the thrust force and eliminate the unbalanced magnetic force.
This paper investigates a homopolar inductor machine (HIM) for flywheel energy storage in electromagnetic launch applications. An equivalent 2-dimension (2-D) finite-element model is presented to ...predict the machine behavior, and the effectiveness of the equivalence is validated by the comparison of 2-D and 3-D results. Based on the 2-D model, the rotor tooth shape is then optimized so as to achieve high fundamental value of the air-gap flux density for a given rotor diameter. It is shown that the proposed 3-D to 2-D equivalence can predict the performance of the HIM in an accurate and fast way, which is quite valuable in the design stage of a HIM.
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