• Progress in Superconductivity and Cryogenics
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• v.9 no.1
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• pp.72-75
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• 2007

Magnetization loss of HTS wire is strongly dependent on the critical current density and the aspect ration of the HTS wire. This paper presents the magnetization loss of stacked BSCCO wire and stacked YBCO wires which had different critical current densities. Width of the BSCCO wire was 4mm and widths of two YBCO wires were 4mm and 8mm. Single wire, two stacked three stacked and four stacked wires were fabricated and tested. Ratio of magnetization loss of BSCCO wire to YBCO wire was presented at single wire. For stacked wire, ratio of magnetization loss of single wire to stacked wire was presented. Test results shows that magnetization losses of stacked wires were greater than that of single wire at large high magnetic field above critical magnetic field.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.93-95
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• 2008

Nowadays more attention is paid to the developing high efficiency electrical machines for energy saving and protection of natural resources. In general, the electromagnetic losses appearing in electrical machines are widely classified into copper loss, core loss and rotor loss. Particularly, in permanent magnet (PM) machines, core loss forms a larger portion of the total losses than in another machine. So, satisfactory prediction of core loss at the design or analysis stage of PM machines is essential to active high efficiency and high performance. This paper deals with analysis of magnetic field distribution due to geometry of stator core for magnetic core loss calculation of multi-pole PM synchronous machine.

• Progress in Superconductivity and Cryogenics
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• v.13 no.2
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• pp.13-16
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• 2011

This paper describes the reduction method of eddy current loss generated into a retaining ring installed in wound-field superconducting machine. In order to suggest the reduction method of eddy current loss of the retaining ring, this paper is divided into three parts. Firstly, eddy current loss of prototype model is calculated. Secondly, eddy current loss versus material and shape of the retaining ring is compared. Finally, the material and the shape of the retaining ring to reduce coupling loss generated by a time-varying magnetic field are proposed. In this paper, eddy current loss is calculated by 3-dimensional transient analysis.

• Spatial Information Research
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• v.17 no.3
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• pp.261-268
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• 2009

This study accomplished to draw a soil erosion map and a grade map of soil loss hazard in Korea. RUSLE and Rainfall-runoff (R) factor, which was estimated by using the rainfall data observed in 59 meteorological stations from 1977 to 2006 (for 30 years). FARD was used to analyze the frequency, and the whole country R factor was estimated according to the frequency. In the analysis of estimating the whole country R factor, Nakdong river has the smallest vaule, but Han river has the biggest value. According to the result of analyzing soil loss, soil loss occurred in a grass land, a bare land and a field in size order, and also approximately 17.2 ton/ha soil loss happened on the whole area. The average soil loss amount by the unit area takes place in a bare land and a grass land a lot. The total amount of soil loss in 5-year-frequency rainfall yields 15,000 ton and, what is more, a lot of soil loss happens in a paddy field, a forest and a crop field. The grade map of soil loss hazard is drawn up by classifying soil loss hazard grade by 5. As a result of analyzing soil loss, the moderate area which is the soil loss hazard grade 2 takes up the largest part, 72.8% of the total soil loss hazard area, on the contrary, the severe soil loss hazard area takes up only $1,038km^2$ (1.1%) of the whole area. The severe soil loss hazard area by land cover shows $93.5km^2$ in a bare land, $168.1km^2$ in a grass land and $327.4km^2$ in a crop field respectively.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.250-252
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• 1997

Phase difference of external magnetic field and self field is known to do an important role in the generation of the AC loss. This paper analize the AC loss of AC superconducting wire in combined action of an AC transport current and AC magnetic field for various phase differences.

• Progress in Superconductivity and Cryogenics
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• v.7 no.3
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• pp.13-16
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• 2005

Multi-stacked HTS tapes are needed to conduct large current in the power application. In this paper magnetization losses of the multi-stacked YBCO coated conductor and the BSCCO tape have been measured and compared. Magnetization losses of single tape, 2-stacked, 3-stacked and 4-stacked HTS tapes have been presented in this paper. Multi-stacked tapes have been fabricated using face-to-face type stacking method. Measurements of magnetization loss were performed under various stacked of external magnetic field to consider the anisotropic characteristics of HTS tapes. Test results show that loss density per unit volume decreased for both YBCO coated conductors and BSCCO tapes when the stacking number of tapes is increased. As the external magnetic field decreased, the ratio of decrement has risen because the full penetration magnetic field(Bp) of the multi-stacked tape is larger than that of the single tape.

• Food Science of Animal Resources
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• v.39 no.4
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• pp.668-676
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• 2019

This study aimed to investigate the effect of an electric field refrigeration (EFR) on the quality characteristics of pork loin including dry aging loss, pH, water holding capacity (WHC), cooking loss, color, shear force, thiobarbituric acid reactive substances (TBARS), and microbial growth during dry aging (0, 1, 2, 3, 4, 7, and 9 wk) in comparison with a commercial refrigerator (CR). Total plate counts (TPC) of the CR group approached 8.07 Log CFU/g at 2 wk of dry aging, thus indicating meat spoilage. Cooking loss, lightness, and shear force of EFR were significantly decreased (p<0.05) at subsequent aging weeks in both the EFR and CR. Aging loss, TPC, TBARS levels increased at subsequent aging weeks; however, pH values were not influenced by aging. At the same aging weeks (1 or 2 wk), the EFR group displayed significantly lower values (p<0.05) of aging loss, pH, TPC, and TBARS levels than the CR group. No significant differences in WHC, cooking loss, and shear force was observed until 2 wk of aging between the EFR and CR groups. The present results show that application of the EFR system improves the tenderness, color, and lipid oxidation stability of pork loin and extends its shelf life in comparison with a commercial refrigeration.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1222-1224
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• 2005

AC loss is an important factor in the development of superconducting tapes and superconducting power applications. In this paper, magnetization loss in YBCO coated conductor have been measured and compared with Brandt equation. Measurements of magnetization loss were performed under various angles of external magnetic field to consider the anisotropic characteristics of YBCO coated conductors. The results show that measured values of magnetization loss agreed well with the calculated value by using Brandt equation, especially at large degrees of incidence angle. The magnetization losses were strongly influenced by the direction of external magnet field as were expected.

• Journal of Magnetics
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• v.13 no.3
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• pp.92-96
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• 2008

There are few reports of high frequency loss behavior in the near-field for magnetic films with semiconducting properties, even though semiconducting magnetic materials, such as soft magnetic amorphous alloys and nanocrystalline thin films, have been demonstrated. The electromagnetic loss behavior of multilayer magnetic films with semiconducting properties on the microstrip line in quasi-microwave frequency band was analyzed numerically using a commercial finite-element based electromagnetic solver. The large increase in the absorption performance and broadband characteristics of the semiconducting/insulating layer magnetic films examined in this study were attributed to an increase in the loss factor of resistive loss. The electromagnetic reflection increased significantly with increasing conductivity, and the loss power deteriorated significantly. The numerical results of the magnetic field distribution showed that a strong radiated signal on the microstrip line was emitted with increasing conductivity and decreasing film thickness due to re-reflection of the radiated wave from the surface of the magnetic film, even though the emitted levels varied with film thickness.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.271-273
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• 2002

The ac loss in Bi-2223 tapes has been studied by a magnetic method. A brief overview of the theoretical background and the experimental set-up is presented. Measurements are made at 77 K in a magnetic fields. The magnitude of the ac loss indicates that filaments are fully coupled, which agrees with theory. As in other measurements, the loss in perpendicular field is larger than that in the parallel field by about a factor 10, which is close to the aspect ratio of the tape.