Journal of Magnetics最新文献_第10页

Investigation of Starting Characteristics with respect to Starting-Bar Shape in a Double-Cage Induction Motor 双笼型异步电动机起动特性与起动杆形状的关系研究

IF 0.5 4区材料科学

Journal of Magnetics Pub Date : 2022-06-30 DOI: 10.4283/jmag.2022.27.2.123

Gyeonghwan Yun, Yongha Choo, Changhwan Kim, Cheewoo Lee

引用次数: 0

Performance Evaluation of MRI Based on Newly Developed MRiLab Simulation Using Inversion Recovery Pulse Sequence with Various Inversion Times 基于不同反转时间的反转恢复脉冲序列MRiLab仿真的MRI性能评价

IF 0.5 4区材料科学

Journal of Magnetics Pub Date : 2022-06-30 DOI: 10.4283/jmag.2022.27.2.210

Gaeun Baek, Jun Lim, J. Yoon, Youngjin Lee

{"title":"Performance Evaluation of MRI Based on Newly Developed MRiLab Simulation Using Inversion Recovery Pulse Sequence with Various Inversion Times","authors":"Gaeun Baek, Jun Lim, J. Yoon, Youngjin Lee","doi":"10.4283/jmag.2022.27.2.210","DOIUrl":"https://doi.org/10.4283/jmag.2022.27.2.210","url":null,"abstract":"Among the representative types of magnetic resonance imaging (MRI) sequences, inversion recovery (IR) can improve the ability to detect brain lesions. The purpose of this study was to confirm the MRI characteristics according to TI changes in IR sequences. In this study, the MRiLab simulation program a newly developed, well-validated program was used to quantitatively analyze image characteristics with respect to the TI value in the IR sequence. Brain tissue phantom and standard phantom images were acquired by changing the TI at 100-ms intervals from 100 to 2,500 ms. In brain tissue phantom images, signal intensity (SI) values showed the lowest signals at TI values of 400, 700, and 2,500 ms in the white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF), respectively. The contrast evaluated in CSF-WM was superior at 400 ms and the lowest at 1,800 ms. In addition, the contrast evaluated in WM-GM was superior at 400 ms and the lowest at 1,500 ms. In the case of the brain standard phantom, the SI and contrast showed the same tendency as brain tissue phantom. In conclusion, an appropriate TI value was derived for obtaining images with excellent SI and contrast between brain tissues using a newly developed simulation program.","PeriodicalId":16147,"journal":{"name":"Journal of Magnetics","volume":"52 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74992991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of a Zero-filling Interpolation with a Real Matrix Size at 1.5 Tesla Based on Spin-echo Weighted Imaging with Various Spatial Resolutions: An ACR Phantom Study 基于不同空间分辨率自旋回波加权成像的1.5特斯拉真实矩阵尺寸的零填充插值比较:ACR幻影研究

IF 0.5 4区材料科学

Journal of Magnetics Pub Date : 2022-06-30 DOI: 10.4283/jmag.2022.27.2.217

Ji-Sung Jang, H. Lee, Seokhwan Yoon, Min-Cheol Jeon, S. Kim

{"title":"Comparison of a Zero-filling Interpolation with a Real Matrix Size at 1.5 Tesla Based on Spin-echo Weighted Imaging with Various Spatial Resolutions: An ACR Phantom Study","authors":"Ji-Sung Jang, H. Lee, Seokhwan Yoon, Min-Cheol Jeon, S. Kim","doi":"10.4283/jmag.2022.27.2.217","DOIUrl":"https://doi.org/10.4283/jmag.2022.27.2.217","url":null,"abstract":"This study aimed to assess the effect of zero-filling interpolation (ZIP) and various spatial resolutions on quality assurance (QA). Two important variables for the assessments of magnetic resonance image quality were included with recommended acceptance criteria: high-contrast spatial resolution and low-contrast object detectability with reference limits. All acquired data were divided into two groups: group A (without ZIP) and group B (with ZIP). The spatial resolutions of both images of T1-weighted and T2-weighted imaging in both directions fulfilled the American College of Radiology (ACR) criterion in group B. The observed high-contrast spatial resolution values were significantly different between the two groups up to a matrix size of 320 × 320 (p < 0.05). On the other hand, with a matrix size ≥ 384 × 384, no significant differences between the two groups were observed in terms of high-contrast spatial resolution (p > 0.05). For low-contrast object detectability, the total number of measured spokes in all groups fulfilled the ACR criterion. However, the low-contrast object detectability values without ZIP tended to decrease as the matrix size decreased. The use of ZIP can improve high-contrast spatial resolution and low-contrast object detectability while reducing image blurriness.","PeriodicalId":16147,"journal":{"name":"Journal of Magnetics","volume":"53 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84460644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of Yttrium and Cerium co-substitution on Structures and Magnetic Properties of Nanocrystalline Nd-Fe-B Magnets 钇和铈共取代对纳米晶钕铁硼磁体结构和磁性能的影响

IF 0.5 4区材料科学

Journal of Magnetics Pub Date : 2022-06-30 DOI: 10.4283/jmag.2022.27.2.155

Xiaoqiang Yu, Lei He, Yuting Hu, Jiajie Li, Xiao Liu, Yuhan Wang, Chunji Li, Munan Yang, Z. Zhong

{"title":"Effects of Yttrium and Cerium co-substitution on Structures and Magnetic Properties of Nanocrystalline Nd-Fe-B Magnets","authors":"Xiaoqiang Yu, Lei He, Yuting Hu, Jiajie Li, Xiao Liu, Yuhan Wang, Chunji Li, Munan Yang, Z. Zhong","doi":"10.4283/jmag.2022.27.2.155","DOIUrl":"https://doi.org/10.4283/jmag.2022.27.2.155","url":null,"abstract":"Cerium-containing (Ce) rare earth magnets with extraordinary cost-effectiveness are widely investigated around the world. However, when the concentration of Ce is much more, the kind of these magnets exhibits very poor thermal stability and overall magnetic properties. To weaken these disadvantages, we take eutectic Y 50 Ce 50 co-substitution alloys into account in this work. Magnetic properties, microstructures and metallurgical behaviors of (Y, Ce, Nd)-Fe-B magnets are systematically researched. For (Y 50 Ce 50 ) 10 Nd 20 Fe 68.9 B 1.1 SPSed permanent magnets, good overall magnetic properties are H cj = 725 kA/m, J r = 0.73 T and ( BH ) max = 81 kJ/m 3 . It schematically depicts that coarse grain zones and fine grain zones occur during the spark plasma sintering (SPS) process. With the Nd content increasing, the deleterious CeFe 2 phases disappear. In addition, the volume fraction and width of coarse grain zones decrease. Ce-rich and Ce-lean regions are also observed in main phases, while Y and Nd elements are uniformly distributed. TEM results show that Nd and Ce are rich in the grain boundary and Y elements prefer to enter in 2:14:1 main phases. This work is favorable to a balanced utilization of high abundance rare earth elements in Nd-Fe-B magnets.","PeriodicalId":16147,"journal":{"name":"Journal of Magnetics","volume":"9 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81904256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High Coercive RE-Fe-B Powders Recycled via HD and HDDR Process from Waste Magnets 从废磁体中回收高矫顽力RE-Fe-B粉末

IF 0.5 4区材料科学

Journal of Magnetics Pub Date : 2022-06-30 DOI: 10.4283/jmag.2022.27.2.117

Taebong Noh, Hee-Ryoung Cha, Yang-Do Kim, Jung-Goo Lee

引用次数: 0

Effect of Direction of Applied Magnetic Field on Magnetization of Coupled Superconducting Filaments 外加磁场方向对耦合超导细丝磁化强度的影响

IF 0.5 4区材料科学

Journal of Magnetics Pub Date : 2022-06-30 DOI: 10.4283/jmag.2022.27.2.141

T. Satiramatekul, Varunya Attasena, F. Bouillault

引用次数: 0

Analysis on Seal Capacity of Magnetic Fluid Seal Using Ring Magnet 环形磁铁磁性流体密封的密封能力分析

IF 0.5 4区材料科学

Journal of Magnetics Pub Date : 2022-03-31 DOI: 10.4283/jmag.2022.27.1.056

Jiawei Liu, Decai Li

引用次数: 1

Sealing Behavior Research on the Radial Ferrofluid Seal Structure with Oblique Teeth 斜齿径向铁磁流体密封结构的密封性能研究

IF 0.5 4区材料科学

Journal of Magnetics Pub Date : 2022-03-31 DOI: 10.4283/jmag.2022.27.1.079

Fang Yuan, Siqi Wang, Decai Li, Long Che

{"title":"Sealing Behavior Research on the Radial Ferrofluid Seal Structure with Oblique Teeth","authors":"Fang Yuan, Siqi Wang, Decai Li, Long Che","doi":"10.4283/jmag.2022.27.1.079","DOIUrl":"https://doi.org/10.4283/jmag.2022.27.1.079","url":null,"abstract":"Considering various unstable factors when the large-diameter spindle operates at a high speed, such as eccentricity, centrifugal force, etc., the ordinary ferrofluid seal structures will show poor sealing performance. This paper proposes an axial-radial bidirectional ferrofluid seal structure with radial oblique teeth to improve the sealing performance. The pressure resistance of the radial ferrofluid seal structure in the magnetic circuit is theoretically analyzed. The magnetic flux distribution characteristic in the gap of the oblique teeth is studied by magnetic field simulation. According to the analysis results of the magnetic induction intensity, to obtain the larger theoretical pressure resistance, the optimal angle of oblique teeth is 77.87°, 64.28° and 62.81° under the radial seal structure with different gaps of 0.1 mm, 0.15 mm and 0.2 mm, respectively. In addition, simulation analysis is carried out to obtain the fluid pressure and velocity distribution of the radial ferrofluid seal structure with different oblique teeth angles. When the oblique teeth angle is small, the pressure drops and gas flow speeds in the ferrofluid area are all lower, and the pressure resistance is higher.","PeriodicalId":16147,"journal":{"name":"Journal of Magnetics","volume":"6 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83498770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of Torque Ripple in an Induction Motor with Respect to Slot Number Combinations 基于槽数组合的异步电动机转矩脉动研究

IF 0.5 4区材料科学

Journal of Magnetics Pub Date : 2022-03-31 DOI: 10.4283/jmag.2022.27.1.018

Yongha Choo, Changhwan Kim, Gyeonghwan Yun, Cheewoo Lee

引用次数: 2

Analysis of Linear Machine by Parameter Study using Equivalent Magnetic Circuit and FEA 线性机床的等效磁路参数分析与有限元分析

IF 0.5 4区材料科学

Journal of Magnetics Pub Date : 2022-03-31 DOI: 10.4283/jmag.2022.27.1.042

Sungin Jeong

{"title":"Analysis of Linear Machine by Parameter Study using Equivalent Magnetic Circuit and FEA","authors":"Sungin Jeong","doi":"10.4283/jmag.2022.27.1.042","DOIUrl":"https://doi.org/10.4283/jmag.2022.27.1.042","url":null,"abstract":"This study proposes an analytical approach by optimum process that is generalized by number of phases, magnet, and pole-pair of linear machines based on a physical magnetic circuit model. The linear machine increases the force output of the machine due to generation of the magnetic field created by the armature winding. There is a strong attractive force between the iron-core armature and the permanent magnet. Therefore, this paper deals not only with one-phase systems by the number of magnet and pole pairs but also two-phase machines in linear machines. All this is carried out for optimum process using geometric parameters based on analytical electromagnetic field research. The best structure for optimum design is selected by a parameter study and it is accomplished with 2-D finite element analysis. The object function and design variables for this parameter study by constraints are chosen for practical and effective design of the machine. Eventually, it suggests new design rules based on optimal design through parameter study. The proposed methods allow us to draw a very important design rule, as a result it can be provided to less time of the machine design and analysis.","PeriodicalId":16147,"journal":{"name":"Journal of Magnetics","volume":"19 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80050948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0