• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2187-2189
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• 2005

It is widely know that one of the most important tasks is the research of plasma for the purpose o nuclear fusion, is to make a stable confinement of high ${\beta}$ value plasma. And, for making the stable confinement, pinch p1-asma produced by reversed field has been mainly studied yet. Magnetic field has been used to hold plasma at high temperature for a long time. Reverse field has shown unstable process. Using ratio frequency, the author could control the instability of the process and formed a stable erversed field. Inthe experiment let a reversed field configuration from by adding-Bias field in advance.

• 한국자기공명학회논문지
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• 제19권1호
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• pp.18-22
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• 2015

The structural geometry of $[N(CH_3)_4]_2CdCl_4$ in a hexagonal phase is studied by $^1H$ MAS NMR, $^{13}C$ CP/MAS NMR, and $^{14}N$ NMR. The changes in the chemical shifts for $^{13}C$ and $^{14}N$ in the hexagonal phase are explained by the structural geometry. In addition, the temperature dependencies of the spin-lattice relaxation time in the rotating frame $T_{1{\rho}}$ for $^1H$ MAS NMR and $^{13}C$ CP/MAS NMR are measured.

• 한국진공학회지
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• 제14권4호
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• pp.171-179
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• 2005

몬테카를로 계산을 통해 표면 거칠기와 세공 표면밀도가 게터의 겉보기 부착계수에 미치는 영향을 정량화했다. 또 부착계수와 게터 내부에서 확산속도에 따라 게터 흡착속도가 어떤 형태로 변화하는지 해석한 결과를 소개한다.

• 한국진공학회지
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• 제15권6호
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• pp.594-604
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• 2006

일정한 기체 공급 압력에서 정해진 만큼 밸브를 개방하는 방식과 밸브를 조절하여 일정한 유량을 흐르도록 하는 두 가지 기체 주입 방식의 작동특성에 대한 시뮬레이션을 통해 공급 압력, 밸브 컨덕턴스, 유량 등 시스템 조건 및 기체 수송관의 길이와 굵기에 따라 기체흐름의 유형이 어떻게 바뀌는지 조사했다.

• 한국초전도ㆍ저온공학회논문지
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• 제24권1호
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• pp.1-7
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• 2022

So far, large-scale scientific devices such as nuclear fusion tokamaks and high energy circular accelerators were constructed using high-current conductors made of metallic superconducting wires. Recently, as REBCO superconducting wires usable in high magnetic fields have been developed by several companies, researchesto apply high current cable type REBCO conductors to next-generation large superconducting magnets were also started. High critical currents of several kA or more in high magnetic fields have been successfully demonstrated on test samples of REBCO cable conductors by several research groups. In this review article, the main features and properties of the representative high current REBCO conductors such as CORC(Conductor On Round Core), TSTC(Twisted Stacked-Tape Cable) and RACC(Roebel-Assembled Coated Conductor), which are currently being developed at abroad are briefly introduced. Research activities of high-current density REBCO MHOS(Multi HTS layers on One Substrate) conductor at KERI, whose structure is different from other cable type REBCO conductors are also shortly introduced.

• Mass Spectrometry Letters
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• 제14권3호
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• pp.110-115
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• 2023

The reaction of (COD)PdCl₂ with new C₃-symmetric tridentate L (COD = 1,5-cyclooctadien; L = 1,3,5-tris(picolinoyloxyethyl)cyanurate) in a mixture of acetone and dichloromethane produces single crystals consisting of unprecedented monometallacyclic [PdCl₂(L)]. This cyclic compound arises from trans-chelation of two of three donating pyridyl groups of L, while the third pyridyl group remains uncoordinated. Electrospray ionization mass spectrometry (ESI-MS) data on L exhibited the major peak corresponding to [C₂₇H₂₄N₆O₉ + H⁺]⁺. Fast atom bombardment mass spectrometry (FABMS) data on [PdCl₂(L)], however, showed the mass peak corresponding to the L instead of the present palladium(II) compound species, due to the insolubility and dissociation in solution. The physicochemical properties of the present palladium(II) compound were fully characterized by means of infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy, thermal analysis, single-crystal X-ray diffraction (SC-XRD) measurement.

• 한국균학회지
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• 제25권2호통권81호
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• pp.143-151
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• 1997

Aspergillus niger와 Penicillium notatum간의 lipase 우수 생성 종간 형질전환체를 획득하고, 유전분석과 정제를 통하여 다음과 같은 결과를 얻었다. P. notatum의 영양요구물을 확인하여 본 결과 Tyrosine 요구성임을 알 수 있었다. 핵전이를 위한 원형질체 형성 및 재생 조건에서는 Novozym 234의 농도 1%, 삼투안정제는 0.6M KCl, 효소의 처리시간은 180분 그리고 최적 pH는 5.8로 나타났다. 핵전이에 의한 형질전환의 빈도는 $1.3{\times}10^{-4}{\sim}3.8{\times}10^{-4}$으로 비교적 낮은 편이었다. 유전적 안정성, conidia의 크기, DNA 함량의 측정 그리고 핵염색의 결과 형질전환체의 핵형은 aneuploid로 추정되었다. 형질전환체의 lipase 활성은 모균주와 비교하여 $1.2{\sim}1.7$배 증가하였다.

• 한국수정란이식학회지
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• 제10권1호
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• pp.65-72
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• 1995

The purposes of this study were to produce cloned rabbit embryos and offsprings by nuclear transplantation(NT) using in vitro matured oocytes as nuclear recipient cytoplasm and to determine the effect of frozen nuclei donor embryos on the production efficiency of cloned embryos. The 8cell embryos were collected from the mated does by flushing oviducts with Dulbecco's phosphate buffered saline containing 10% fetal calf serum(FCS) at 40 hours after hGG injection. A portion of collected embryos were preserved at 4$^{\circ}C$ for 24 hours and a portion of them were frozen by vitrification method. The embryos used for donor nuclei were synchronized in the phase of Gi /S transition. The in vitro matured oocytes were used as recipient cytoplasm following removing the nucleus and the first polar body. The synchronized blastomeres from fresh, cooled or frozen embryos were injected into the enucleated oocytes by micromanipulation and were electrofused by electrical stimulation of three pulses for 60 $\mu$sec at 1.0 W /cm in 0.28 M mannitol solution. The fused oocytes were co-cultured with a monolayer of rabbit oviductal epithelial cells in M-199 solution containing 10% FCS for 120 hours at 39$^{\circ}C$ in a 5% $CO_2$incubator. Following in vitro culture of the NT embryos to blastocyst stage, they were stained with Hoechst 33342 dye for counting the number of blastomeres by fluorescence microscopy. The nuclear transplant embryos developed in vitro to 2- to 4-cell stage were transferred into the oviducts of synchronized recipient does. The results obtained were summarized as follows: 1. The fusion rates of the blastomeres from fresh, cooled and frozen embryos with the in vitro matured and enucleated oocytes were 100, 95.8 and 64, 3%, respectively. 2. Development in vitro to blastocyst was significantly(p<0.05) different between the cloned embryos with the blastomeres from fresh, cooled or frozen embryos as 39.0, 20. 9 and 15.7%, respectively. 3. The mean numbers of cell cycle per day during in vitro culture of cloned embryos blastomeres from fresh, cooled or frozen embryos was 1.31, 1.29 and 1.16, respectively. 4. A total of 77 nuclear transplant embryos were transferred into 6 recipient does, of which two offsprings were produced from a foster mother 31 days after embryo transfer.

• 핵의학기술
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• 제27권1호
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• pp.47-54
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• 2023

Purpose PET-CT imaging require an appropriate quality assurance system to achieve high efficiency and reliability. Quality control is essential for improving the quality of care and patient safety. Currently, there are performance evaluation methods of UN2-1994 and UN2-2001 proposed by NEMA and IEC for PET-CT image evaluation. In this study, we compare phantom images with the same experiments before and after PET-CT 3D normalization and well counter correction and evaluate the usefulness of quality control. Materials and methods Discovery 690 (General Electric Healthcare, USA) PET-CT equiptment was used to perform 3D normalization and well counter correction as recommended by GE Healthcare. Based on the recovery coefficients for the six spheres of the NEMA IEC Body Phantom recommended by the EARL. 20kBq/㎖ of ¹⁸F was injected into the sphere of the phantom and 2kBq/㎖ of ¹⁸F was injected into the body of phantom. PET-CT scan was performed with a radioacitivity ratio of 10:1. Images were reconstructed by appliying TOF+PSF+TOF, OSEM+PSF, OSEM and Gaussian filter 4.0, 4.5, 5.0, 5.5, 6.0, 6,5 mm with matrix size 128×128, slice thickness 3.75 mm, iteration 2, subset 16 conditions. The PET image was attenuation corrected using the CT images and analyzed using software program AW 4.7 (General Electric Healthcare, USA). The ROI was set to fit 6 spheres in the CT image, RC (Recovery Coefficient) was measured after fusion of PET and CT. Statistical analysis was performed wilcoxon signed rank test using R. Results Overall, after the quality control items were performed, the recovery coefficient of the phantom image increased and measured. Recovery coefficient according to the image reconstruction increased in the order TOF+PSF, TOF, OSEM+PSF, before and after quality control, RCmax increased by OSEM 0.13, OSEM+PSF 0.16, TOF 0.16, TOF+PSF 0.15 and RCmean increased by OSEM 0.09, OSEM+PSF 0.09, TOF 0.106, TOF+PSF 0.10. Both groups showed a statistically significant difference in Wilcoxon signed rank test results (P value<0.001). Conclusion PET-CT system require quality assurance to achieve high efficiency and reliability. Standardized intervals and procedures should be followed for quality control. We hope that this study will be a good opportunity to think about the importance of quality control in PET-CT

• 핵의학기술
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• 제14권2호
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• pp.33-37
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• 2010

관상동맥질환의 진단 및 평가에 있어서 myocardial perfusion SPECT검사와 FDG를 이용한 myocardial PET검사 그리고 PET/CT에 장착된 64-slice CT를 이용한 coronary CT angiography를 동시에 실행함으로 검사의 신뢰도와 편의성을 한층 더 높이고자 한다. 먼저 약물부하 myocardial perfusion SPECT검사를 먼저 시행한다. 환자의 피폭경감을 위해서 $^{99m}Tc$-MIBI 10 mCi 로 주사하며 myocardial PET검사를 위해서 지방식을 먹지 않고 ursodeoxcholic acid 100 mg을 생수와 함께 복용하게 하여 1시간 후에 SPECT 영상을 얻는다. 이어서 myocardial FDG PET검사를 시행한다. 혈중의 지방산 농도를 낮추고 심장의 FDG섭취율을 증가시키기 위해 혈중 포도당 농도치에 따라 insulin과 Acipimox를 함께 사용하는 독창적인 경구 당 부하법을 사용하였으며, 환자의 피폭 경감을 위해서 $^{18}F$-FDG 5 mCi를 주사하고 1시간 후에 10분간 gated 영상을 얻으며 필요시 delay 영상을 얻는다. PET검사가 끝남과 동시에 환자는 동일한 position을 하고 연속해서 coronary CTA를 시행한다. 이 검사에서 가장 중요한 것은 심박동수 조절과 환자의 호흡협조이다. 심박동수를 65회 이하로 낮추기 위해 beta blocker 50 mg~200 mg을 의사와 상의하여 복용케 하고 호흡법을 충분히 연습을 시키다. 검사 직전에 isosorbide dinitrate를 3~5회 분무하여 혈관벽의 긴장을 낮추고 혈관을 확장시켜서 coronary artery의 해부학적 형태를 더욱 잘 나타낼 수 있게 한다. 촬영 시 CT 조영제를 4.0~5.0 mL/sec의 압력으로 주입하며 촬영을 한다. Coronary CTA를 이용하면 coronary artery stenosis가 잘 보이며, 약물부하 myocardial perfusion SPECT로 coronary CTA에서 보인 stenosis와 perfusion저하의 상관관계를 검토(culprit vessel 확인)할 수 있으며, FDG PET으로 hibernating myocardium 또는 infarction site의 viability를 확인할 수 있다. 한 가지 검사로 lesion site와 severity 및 치료에 대한 반응 예측이 가능함으로 약물치료, PCI, CABG 등 치료방향을 설정할 수 있다. 또한 모든 검사 과정들이 연속적으로 동시에 이루어지기 때문에 짧은 시간(3시간) 내에 one-stop으로 검사를 종료할 수 있는 큰 장점을 가지게 된다. 그러므로 이 검사법은 ischemic heart disease의 one-stop evaluation에 있어서 유용한 protocol로 보여진다.