• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.256-259
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• 2003

The study of confined liquid crystals flourished in the decade of the nineties. Liquid crystals properties have been probed after confinement in well-defined or interconnected geometries as those available in porous media and in polymer networks. In this work we emphasized the power of the nuclear magnetic resonance technique to determine the confined liquid crystal structures. We also present unexpected results on the dependence of the confined liquid crystal configuration on the chain length.

• Journal of Information Display
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• 제4권1호
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• pp.14-16
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• 2003

The study of confined liquid crystals flourished in the decade of the nineties. Liquid crystals properties have been probed after confinement in well-defined or interconnected geometries as those available in porous media and in polymer networks. In this work we emphasized the power of the nuclear magnetic resonance technique to determine the confined liquid crystal structures. We also present unexpected results on the dependence of the confined liquid crystal configuration on the chain length.

• 한국자기공명학회논문지
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• 제24권4호
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• pp.96-103
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• 2020

A new NMR method to monitor solvent-localized NMR signals in the two-phase liquid system is suggested. This method based on intermolecular single-quantum coherence (iSQC). Here, we exploited the feature of the local action of distant dipolar field (DDF) effect in order to filter out specific NMR signals dissolved in different solvents. This solvent specific iSQC spectroscopy was carried out on a model two-phase liquid system (D-glucose in water/palmitic acid in chloroform), and showed solvent-localized NMR signals. We believe our approaches might be useful in metabolic analysis such as two-phase liquid extraction scheme for labile chemical species.

• 한국주조공학회지
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• 제29권1호
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• pp.38-44
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• 2009

Magnetic separation of Fe contaminated Al-Si cutting chip scraps was performed for the recyclability assessment. It was also aimed to investigate the casting and solidification characteristics of the cutting chip scraps. The magnetically separated cutting chip scraps were adequately treated for the casting procedure and test specimens were made into a stepped mold inducing different cooling rates. The test specimens were evaluated by the combined analysis of ICP, Spectroscopy, OM-image analyzer, SEM/EDS, etc. Solidification characteristics of cutting chip scraps were examined as functions of Fe content and cooling rate. It is concluded that the magnetic separation process can be utilized to recycle the Fe contaminated Al-Si cutting chip scraps in the high cooling rate foundry process.

• 설비공학논문집
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• 제16권12호
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• pp.1101-1106
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• 2004

Magnetic refrigeration is based on the magnetocaloric effect (MCE)-the ability of some materials to heat up when magnetized and cool down when demagnetized. A rotary magnetic refrigeration device using gadolinium (Gd) ribbon and permanent magnets was constructed for experimental study. Gd ribbon attached around a rotating wheel is cyclically magnetized and demagnetized by permanent magnets and exchanges heat with liquid in the surrounding container. Temperature of the liquid in each divided section of the container was measured and the experimental results obtained in this study were discussed.

• E2M - 전기 전자와 첨단 소재
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• 제11권10호
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• pp.40-45
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• 1998

This paper describes a collaborative work between SEI and KEPCO on the Superconducting Magnetic Energy Storage system (SMES). We have studied two types of magnets. One is the 400kJ class LTS-SMES for testing the power stabilization operated at liquid helium temperature (4.2K) and the other is the 100J class HTS-SMES for confirming the possibility of applying HTS wire to SMES at liquid nitrogen temperature (77k). In this paper, the design of the magnet and the test results are described. Each magnet performed completely at rated operation.

• 한국자기공명학회논문지
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• 제12권1호
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• pp.60-64
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• 2008

Cross-polarization (CP) signals were observed even from liquid samples such as neat toluene. Therefore, CP signals of liquid molecules in the presence of high surface materials do not necessarily mean the molecules are adsorbed on solid surface, especially when no signal from the tertiary observing nuclei such as carbons of the molecules is detected.

• Investigative Magnetic Resonance Imaging
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• 제22권3호
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• pp.141-149
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• 2018

Purpose: The purpose of this study is to develop a simple method to measure magnetic susceptibility of arbitrarily shaped materials through MR imaging and numerical modeling. Materials and Methods: Our 3D printed phantom consists of a lower compartment filled with a gel (gel part) and an upper compartment for placing a susceptibility object (object part). The $B_0$ maps of the gel with and without the object were reconstructed from phase images obtained in a 3T MRI scanner. Then, their difference was compared with a numerically modeled $B_0$ map based on the geometry of the object, obtained by a separate MRI scan of the object possibly immersed in an MR-visible liquid. The susceptibility of the object was determined by a least-squares fit. Results: A total of 18 solid and liquid samples were tested, with measured susceptibility values in the range of -12.6 to 28.28 ppm. To confirm accuracy of the method, independently obtained reference values were compared with measured susceptibility when possible. The comparison revealed that our method can determine susceptibility within approximately 5%, likely limited by the object shape modeling error. Conclusion: The proposed gel-phantom-based susceptibility measurement may be used to effectively measure magnetic susceptibility of MR-compatible samples with an arbitrary shape, and can enable development of various MR engineering parts as well as test biological tissue specimens.

• 한국초전도ㆍ저온공학회논문지
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• 제23권3호
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• pp.37-40
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• 2021

Nickel (Ni) is a kind of the rare earth resources. Since Ni-containing waste is drained after several plating operations in the factories, the effective recycling technique has been expected to be introduced. An actual magnetic separation technique using HTS bulk magnet generating the strong magnetic field has succeeded in collecting the paramagnetic slurry containing Ni-sulphate coarse crystals which were fabricated from the Ni-plating waste. The Ni compound in the collected slurry was identified as NiSO₄/6H₂O, showing slight differences in the particle size and magnetic susceptibility between the samples attracted and not-attract to the magnetic pole. This preferential extraction suggests us a novel recycling method of Ni resource because the compound is capable of recycling back to the plating processes as a raw material.

• 한국자기학회지
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• 제13권3호
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• pp.127-132
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• 2003

자성유체의 자연대류는 부력 이외에 자기체적력이 존재하기 때문에 뉴턴유체와 다르다. 본 연구에서는 좌측 및 우측 벽면이 고온 및 저온으로 설정된 정방형 케비티 공간내에서 자성유체의 자연대류를 실험하였다 실험은 열전대에 의한 온도측정과 감온액정에 의한 가시화를 실시하였다. 그 결과 케비티 공간내 자성유체의 전열특성 및 외부에서 가하는 자장의 방향과 세기에 따라 자연대류가 제어됨을 알 수 있었다.