• 한국자기공명학회논문지
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• 제24권2호
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• pp.47-52
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• 2020

Liquid-liquid phase separation (LLPS) of biomolecules, a newly-found phase behavior of molecules in the liquid phase, has shown to its relationship to various biological function and misfolding diseases. Extensive studies have increasingly revealed a general mechanism of LLPS and characterized the liquid droplet; ho wever, intermolecular interactions of proteins and structural states of LLPS-inducing proteins inside of the droplet remain largely unknown. Solution NMR spectroscopy has emerged as a powerful approach as it provides invaluable information on protein intermolecular interactions and structures at the atomic and residue level. We herein comprehensively address useful techniques of solution NMR including the effect of paramagnetic relaxation enhancement for the study on the LLPS and droplet based on recent studies.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3098-3103
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• 2007

In this paper, natural convection of a magnetic fluids(W-40) in a half circular pipe enclosure are investigated by numerical and experimental method. One side wall is kept at a constant temperature(25$^{\circ}C$), and the opposite side wall is also kept at a constant temperature(20$^{\circ}C$). Under above conditions, various magnitudes of the magnetic fields were applied up. Theoretical study through the governing equation derived by Siliomis is carried out with numerical analysis by the GSMAC Method. And the thermo-sensitive liquid crystal film(R20C5A) is utilized in order to visualize wall-temperature distributions as an experimental method. This study has resulted in the following fact that the natural convection of a magnetic fluids are controlled by the direction and intensity of the magnetic fields.

• 한국분말재료학회지
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• 제24권2호
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• pp.122-127
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• 2017

Fe-6.5 wt.% Si alloys are widely known to have excellent soft magnetic properties such as high magnetic flux density, low coercivity, and low core loss at high frequency. In this work, disc-shaped preforms are prepared by spark plasma sintering at 1223 K after inert gas atomization of Fe-6.5 wt.% Si powders. Fe-6.5 wt.% Si sheets are rolled by a powder hot-rolling process without cracking, and their microstructure and soft magnetic properties are investigated. The microstructure and magnetic properties (saturation magnetization and core loss) of the hot-rolled Fe-6.5 wt.% Si sheets are examined by scanning electron microscopy, electron backscatter diffraction, vibration sample magnetometry, and AC B-H analysis. The Fe-6.5 wt.% Si sheet rolled at a total reduction ratio of 80% exhibits good soft magnetic properties such as a saturation magnetization of 1.74 T and core loss ($W_{5/1000}$) of 30.7 W/kg. This result is caused by an increase in the electrical resistivity resulting from an increased particle boundary density and the oxide layers between the primary particle boundaries.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.27.2-27.2
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• 2007

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 춘계학술논문요약집
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• pp.275-276
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• 2017

• 한국초전도ㆍ저온공학회논문지
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• 제22권4호
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• pp.1-5
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• 2020

Heart consists of myocardium cells and the electrophysiological activity of the cells generate magnetic fields. By measuring this magnetic field, magnetocardiogram (MCG), functional diagnosis of the heart diseases is possible. Since the strength of the MCG signals is weak, typically in the range of 1-10 pT, we need sensitive magnetic sensors. Conventionally, superconducting quantum interference devices (SQUID)s were used for the detection of MCG signals due to its superior sensitivity to other magnetic sensors. However, drawback of the SQUID is the need for regular refill of a cryogenic liquid, typically liquid helium for cooling low-temperature SQUIDs. Efforts to eliminate the need for the refill in the SQUID system have been done by using cryocooler-based conduction cooling or use of non-cryogenic sensors, or room-temperature sensors. Each sensor has advantage and disadvantage, in terms of magnetic field sensitivity and complexity of the system, and we review the recent trend of MCG technology.

• 한국자기공명학회논문지
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• 제15권1호
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• pp.14-24
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• 2011

We have performed Liquid Chromatography-Solid Phase Extraction-NMR (LC-SPE-NMR) analysis for liquid crystalline mixture and elucidated the structures of selected components by NMR spectra. Combining the results of one-dimensional 1H experiments as well as homonuclear and heteronuclear two-dimensional experiments, we could analyze the molecular structure of the liquid crystal singles whose structure had not been interpretable by mass spectrometry alone.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.906-908
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• 2003

A Linear induction electromagnetic(EM) pump of liquid metal fast breeder reactor(LMFBR) is used for the purpose that the liquid metal of high temperature is transported by EM force. This paper evaluates magnetic flux density necessary for transporting liquid metal, using analytical model of the linear induction EM pump. Using the 2-D finite element method(2-D FEM), magnetic flux density is estimated in consideration of a geometric model, electric parameter, and velocity of liquid metal. From the viewpoint of hydrodynamics, the results can be used for flow analysis of the liquid metal.

• 한국분말재료학회지
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• 제29권6호
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• pp.459-467
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• 2022

Soft magnetic powder materials are used throughout industries such as motors and power converters. When manufacturing Fe-based soft magnetic composites, the size and shape of the soft magnetic powder and the microstructure in the powder are closely related to the magnetic properties. In this study, Fe-Si-Al-P alloy powders were manufactured using various manufacturing process parameter sets, and the process parameters of the vacuum induction melt gas atomization process were set as melt temperature, atomization gas pressure, and gas flow rate. Process variable data that records are converted into 6 types of data for each powder recovery section. Process variable data that recorded minute changes were converted into 6 types of data and used as input variables. As output variables, a total of 6 types were designated by measuring the particle size, flowability, apparent density, and sphericity of the manufactured powders according to the process variable conditions. The sensitivity of the input and output variables was analyzed through the Pearson correlation coefficient, and a total of 6 powder characteristics were analyzed by artificial neural network model. The prediction results were compared with the results through linear regression analysis and response surface methodology, respectively.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.373-374
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• 2002

Magnetic fluid seals are used in a wide variety of gas and dust sealing applications. However, it is difficult to seal for liquid because of its characteristic. This study will be a basic guide for a magnetic fluid seal for liquid, especially for blood to be practically used in medical instruments such as rotary blood pumps by clarifying its seal properties. Sealing pressure test, durability test, and hemolysis test have been conducted for this seal. In this study, magnetic fluid, sealing fluid, eccentricity ratio, revolution speed were selected as parameters. As results of the tests, it has been found that the properties of magnetic fluid seal depend on the solvent and the saturation magnetization of magnetic fluid. Therefore, the selection of magnetic fluid is important for this seal. It also has been found that eccentricity ratio of the shaft caused harmful effect for seal properties. In conclusion, it has been showed that magnetic fluid seals could be possibly used in medical instruments such as blood pumps when blood come in contact with magnetic fluids.