• Bulletin of the Korean Chemical Society
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• 제22권10호
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• pp.1111-1119
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• 2001

• Bulletin of the Korean Chemical Society
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• 제22권10호
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• pp.1149-1152
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• 2001

• 한국전기전자재료학회논문지
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• 제21권10호
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• pp.943-949
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• 2008

We report on the development of transition edge sensors for x-ray detection. The sensor technology was based on the fabrication of a superconducting film on a thin membrane. A bilayer of a superconductor, Ti, and a noble metal, Au, was e-beam evaporated on a micromachined SiNx. Another Au layer was evaporated on the two side edges of the bilayer in order not to be affected by structural imperfections at the boundaries. With the method described in the present report, the superconducting transition temperature of the device was consistently achieved to near 80 mK with a sharp transition. The energy spectrum ueasured with the device provided 37 eV FWHM for 5.9 x-rays. We also discuss the design and fabrication considerations as well as the performance of the device in detail.

• Progress in Superconductivity
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• 제9권2호
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• pp.162-166
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• 2008

We are developing a sensitive gamma ray spectrometer based on superconducting transition edge sensors. The detector consists of a small piece of high purity Sn as an absorber and a Ti/Au bilayer as a temperature sensor. It is designed to measure the thermal signal caused by absorption of gamma rays. The mechanical support and the thermal contact between the absorber and the thermometer were made with Stycast epoxy. The bilayer was formed by e-beam evaporation and patterned by wet etching on top of a $SiN_X$ membrane. A sharp superconducting transition of the film was measured near 100 mK. When the film was biased to the edge of the transition, signals were observed due to single photon absorption emitted from an $^{241}Am$ source. The measured spectrum showed several characteristic peaks of the source including 59.5 keV gamma line. The full with at half maximum was about 900 eV for the 59.5 keV gamma line. The background was low enough to resolve low energy lines. Considerations to improve the energy resolution of the gamma ray spectrometer are also discussed.

• 공업화학
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• 제32권5호
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• pp.556-561
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• 2021

최근 산화철 나노입자는 외부의 자기장에 반응하는 자성의 특성과 생체적합성이 뛰어나 약물전달시스템(drug delivery system, DDS)에 관한 많은 연구의 소재로 사용되어져 왔다. 본 연구에서는 마이크로니들(microneedles, MNs)의 매트릭스 물질로 HA (hyaluronic acid)와 CMC (carboxy methyl cellulose)를 이용하여 SIONs (superparamagnetic iron oxide nanoparticles)이 함유된 HA-SMNs (hyaluronic acid-superparamagnetic microneedles)와 CMC-SMNs (carboxy methyl cellulose-superparamagnetic microneedles)를 제조하였으며, SEM (scanning electron microscopic), SQUD-VSM (superconducting quantum interference device-vibrating sample magnetometer), FMMD (frequency mixing magnetic detection), 고분자 및 바이오 멤브레인을 이용하여 SMNs의 다양한 특성을 조사하였다. SQUID-VSM 측정 결과 SIONs이 포함된 HA-SMNs와 CMC-SMNs에서 초상자성의 특성이 나타났으며, FMMD 측정에서는 SIONs 농도가 증가함에 따라 신호 강도에 변화가 확인되었다. 또한 SMNs의 바이오 막을 통한 HA-SMNs와 CMC-SMNs의 투과도 분석에서는 각각 평균 92.5%와 98.5%의 피부 투과율이 조사되었다. 이러한 결과를 통해 SMNs 제형은 경피약물전달시스템(transdermal drug delivery system, TDDS) 및 MR(magnetic mesonance) molecular imaging 분야의 전달소재로 활용될 수 있을 것으로 기대한다.

• 한국초전도ㆍ저온공학회논문지
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• 제19권1호
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• pp.51-55
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• 2017

To obtain Nuclear Magnetic Resonance (NMR) measurement of membrane protein, an NMR magnet is required to generate high intensity, homogeneity, and stability of field. A High-Temperature Superconducting (HTS) magnet is a promising alternative to a conventional Low-Temperature Superconducting (LTS) NMR magnet for high field, current density, and stability margin. Conventionally, an HTS coil has been wound by several winding techniques such as Single-Pancake (SP), Double-Pancake (DP), and layer-wound. The DP winding technique has been frequently used for a large magnet because long HTS wire is generally difficult to manufacture, and maintenance of magnet is convenient. However, magnetic field generated by the slanted turns and the splice leads to field inhomogeneity in Diameter of Spherical Volume (DSV). The field inhomogeneity degrades performance of NMR spectrometer and thus effect of the slanted turns and the splice should be analyzed. In this paper, field gradient of HTS double-pancake coils considering the slanted turns and the splice was calculated using Biot-Savart law and numerical integration. The calculation results showed that magnetic field produced by the slanted turns and the splice caused significant inhomogeneity of field.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2003년도 High Temperature Superconductivity Vol.XIII
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• pp.51-51
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• 2003

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 춘계학술대회논문집
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• pp.90-106
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• 1995

The "O"S' BONDING make metallic and non-metalic crystal structures and form localized superconducting orbitals , which induce electrical conduction , semi-conduction, and superconduction. The orbitals are proced by Ampere's law, Faraday's law , Meissner effect, highcritical temperature of thecopper oxide layers. abnomal trans-membrane signal in cancer cell and plastic deformations bytwins and dislocations, In the case of alloying metals, the most deterimentla cases of electrical conduction are those of solid solution and intermetalic compound . The highest case for the hardness are also those of solid solution and intermetallic compound. It explains the contributions of the "O"S' BONDING for conduction bands and plastic deformation by twins and dislocations.ns and dislocations.

• 한국자기학회지
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• 제13권2호
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• pp.59-63
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• 2003

고분자 재료인 이온교환수지 박막 안에서의 이온교환반응과 전기화학적 환원반응을 이용하여 코발트 나노 입자를 제조하였다. 코발트 나노 입자의 구조와 자기특성을 투과전자현미경과 초전도양자간섭기를 이용하여 고찰하였다. 투과전자현미경 결과로부터 고분자 박막(MF-4SK) 1 gram에 코발트가 $7.8{\times}10^{19}$ atoms 포함된 시편에서 코발트가 나노 크기로 입자를 형성하고 있음을 확인하였으며, 자기측정 결과로부터 코발트 나노 입자가 blocking temperature($T_{B}$) 이상에서 초상자성을 나타내는 것을 확인하였다. 온도에 따른 자화 측정 곡선으로부터 500 Oe 자기장 하에서 $T_{B}$가 대략 185 K인 결과를 얻었으며, 300 K에서의 자화곡선(M-H곡선) 결과를 이용하여 Langevin function fit하여 계산한 코발트 입자의 평균 반경은 4.0 nm로, 투과전자현미경으로 관찰한 크기와 일치하는 것을 확인하였다. 이 결과는 고분자 박막 내에서 코발트 나노 입자가 자성 단상(single domain) 구조를 이루고 있음을 보여주는 것으로, 강자성 나노 입자들의 초상자성 거동을 고찰하였다.