• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1614-1627
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• 2016

The purpose of this paper is to investigate the united Electromagnetic characteristics for the effective monitoring on the static air-gap eccentricity (SAGE) of turbo-generator. Different from other studies, this paper not only studies on the unbalanced magnetic pull (UMP) and the vibration characteristics of the stator and the rotor, but also investigates the harmonic features of the magnetic flux density and the circulating current inside the parallel branches (CCPB). The theoretical calculation, together with the finite-element-method (FEM) simulation and the experiment verification, is taken for a SDF-9 type non-salient generator. It is shown that, when SAGE occurs, apparent double-frequency UMP and vibrations will be produced both on the stator and the rotor, while the CCPB will have an obvious increment at the $1^{st}$ harmonic component. In addition, the amplitude of the magnetic flux density will be of cosine distribution in the circumferential position of the air-gap, while in normal condition it is a constant. Moreover, the pass-band amplitude, together with the $1^{st}$ harmonic of the magnetic flux density, will be enlarged as well. These united electromagnetic characteristics can be used as the diagnosis and monitoring criterion for SAGE.

• Development and Reproduction
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• v.26 no.2
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• pp.91-98
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• 2022

Genomic DNA (gDNA) set apart from two populations of Korean Charybdis crab (Charybdis japonica) was augmented by PCR experiments. The five oligonucleotides primers (ONT-primers) were spent to yield the number of unique loci shared to each crab population (ULSECP) and number of loci shared by the two crab populations (LSTCP). 305 fragments (FRAGs) were identified in the Charybdis crab population A (CCPA), and 344 in the Charybdis crab population B (CCPB): 44 number of ULSECP (14.43%) in the CCPA and 110 (31.98%) in the CCPB. 44 number of LSTCP, with an average of 8.8 per primer, were detected in the two crab populations. The bandsharing (BS) value between entity's no. 01 and no. 10 was the lowest (0.371) between the two CCPs. The average bandsharing (ABS) values of individuals in the CCPA (0.575±0.014) were lesser than in those originated from the CCPB (0.705±0.011) (p < 0.05). The polar hierarchical dendrogram (PHD) achieved by the five ONT-primers denotes three genetic clusters (GCs): cluster I (CHARYBCRAB 01, 04, 05, 06, and 08), cluster II (CHARYBCRAB 02, 03, 07, 09, 10, and 11) and cluster III (CHARYBCRAB 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, and 22). The shortest genetic distance (GD) displaying significant molecular difference (MD) was between individuals CHARYBCRAB no. 18 and CHARYBCRAB no. 17 (0.055).