• Nuclear Engineering and Technology
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• 제40권6호
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• pp.439-450
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• 2008

The KSTAR device succeeded in first plasma generation on $13^{th}$ June of 2008 through comprehensive system test and commissioning. Among various kinds of the key factors that decisively affected the project, success in the construction and assembly of the major tokamak structure was most important one. Every engineering aspects of each structure were finally confirmed in the integrated commissioning period, and there were no severe troubles and failures prevented the KSTAR device from operating during the commissioning and the first plasma experiments. As a result, all of the experiences and technologies achieved through the KSTAR construction process are expected to be important fundamentals for future construction projects of superconducting fusion devices. This paper summarizes key engineering features of the major structures and of the machine assembly.

• PNF and Movement
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• 제4권1호
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• pp.51-62
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• 2006

Purpose : The purposes of this study were to test the effect of proprioceptive and vestibular sensory input on expression of BDNF after traumatic brain injury in the rat. Subject : The control group was sacrificed at 24 hours after traumatic brain injury. The experimental group I was housed in standard cage for 7 days. The experimental group II was housed in standard cage after intervention to proprioceptive and vestibular sensory(balance training) for 7 days. Method : Traumatic brain injury was induced by weight drop model and after operation they were housed in individual standard cages for 24 hours. After 7th day, rats were sacrificed and cryostat coronal sections were processed individual1y in goat polyclonal anti-BDNF antibody. The morphologic characteristics and the BDNF expression were investigated in injured hemisphere section and contralateral brain section from immunohistochemistry using light microscope. Result : The results of this experiment were as follows: 1. In control group, cell bodies in lateral nucleus of cerebellum, superior vestibular nucleus, purkinje cell layer of cerebellum and pontine nucleus changed morphologically. 2. The expression of BDNF in contralateral hemisphere of group II were revealed. 3. On 7th day after operation, immunohistochemical response of BDNF in lateral nucleus, superior vestibular nucleus, purkinje cell layer and pontine nucleus appeared in group II. Conclusion : The present results revealed that intervention to proprioceptive and vestibular sensory input is enhance expression of BDNF and it is useful in neuronal reorganization improvement after traumatic brain injury.

• PNF and Movement
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• 제5권1호
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• pp.9-17
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• 2007

Purpose : The purpose of this study was to test the effect of balance training for proprioceptive and vestibular sensory stimulation and therapeutic environment on expression of BDNF after traumatic brain injury in the rat. Subject : Twelve Sprague-Dawley rats were randomly assigned into group I and group II. After traumatic brain injury, group I was housed in standard cage for 7 days. Group II was housed in therapeutic cage after balance training for 7 days. Method : Traumatic brain injury was induced by weight drop model and after operation they were housed in individual standard cages for 24 hours. After 7th day, the rats were sacrificed and cryostat coronal sections were processed individually in goat polyclonal anti-BDNF antibody. The morphologic characteristics and the BDNF expression were investigated in injured hemisphere section from immunohistochemistry using light microscope. Result : Immunohistochemical response of BDNF in lateral nucleus, purkinje cell layer, superior vestibular nucleus and pontine nucleus appeared very higher in group II than in group I Conclusion : The present result revealed that simultaneously application of balance training for proprioceptive and vestibular sensory stimulation input and therapeutic environment in traumatic brain injured rats is enhance expression of BDNF and it is facilitates neural plasticity.

• 한국동물학회지
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• 제33권2호
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• pp.152-157
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• 1990

면역조직화학적 방법을 이용하여 생쥐 난소에서 $\beta$-endorphin이 생성되는 부위를 조사하기 위하여 본 실험을 행하였다. 성숙한 생쥐를 4% neutral buffered paraformaldehyde로 관류고정하였으며 난소를 적출한 후 cryostat로 절편을 만들어 avidin-biotin complex(ABC)를 이용하여 면역색을 하였다. $\beta$-endorphin에 대한 항체반응은 주로 황체에서 일어났으며, theac interna와 theca externa에서는 반응이 나타나지 않았다. 황체에서의 염색 양상은 퇴화가 많이 진행된 황체세포에서 보다 강한 연색반응을 관찰할 수 있었다. 때로 황체세포에서 유래된 것으로 보이는 간질세포에서도 양성반응을 관찰할 수 있었다. 이외에도 large antral follicle의 여포강에 인접한 과립세포에서 약한 반응을 보여주었으나, 제 1차 여포에서는 양성반응이 나타나지 않았다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권1호
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• pp.23-26
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• 2003

This paper presents conceptual design and 3-D electromagnetic analysis of IMVA transformer with BSCCO-2223 High Tc Superconducting (HTS) tapes. The rated voltages of each sides of the transformer are 22.9 kV and 6.6 kV, and double pancake windings were adopted. High voltage and Low voltage sides were composed of several double pancake windings. Four HTS tapes were wound in parallel for the windings of low voltage side and were transposed in order to distribute the currents equally in each conductor The transformer core was designed as a shell type core made of laminated silicon steel plates and the core is separated with the windings by a cryostat with Fiberglass Reinforced Plastics(FRP). A sub-cooling system using L$N_2$ were designed to maintain the coolant temperature 65K. Finally perpendicular components of magnetic field applied to tapes were calculated 0.247 in the rated operation using 3-D analysis. A real 1MVA HTS transformer will be manufactured in near future based on the design parameters presented in this paper.

• 한국초전도ㆍ저온공학회논문지
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• 제9권3호
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• pp.62-66
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• 2007

Electromagnetic forces (Attractive and repulsive force), interacting between current leads show different tendency according to the arrangement of current leads on the top flange of the cryostat and the distance of each lead. Especially in case of high-current electric power devices or high-field magnets, optimal arrangement of current leads becomes one of the safety issues to be considered for minimizing the electromagnetic for ce acting on them. In this paper, we suggest an optimal arrangement method with three pairs of current leads for a 24kV class 650A superconducting fault current limiter (SFCL) system which has a probability of unpredicted fault currents(i.e, 20kA).

• 한국초전도ㆍ저온공학회논문지
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• 제11권1호
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• pp.16-19
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• 2009

Recently, for improvement of the magnetic field of high temperature superconductor (HTS) apparatus, many studies investigating on operating in the range of $20{\sim}65K$ with liquid helium or the conducting method using cryocooler is actively reviewed. Also, the cooling method using solid nitrogen as cryogen is being suggested. Since the nitrogen has very large specific heat in solid state, it is expected that it can enable long time operation without a continuous supply of cooling energy. However, there is still insufficient data on the characteristics of solid nitrogen such as thermodynamic properties and liquid-solid phase change. Especially, there was almost no study done on the electrical insulation properties of solid nitrogen so far. In this study, solid nitrogen to find the electrical characteristics was made by using cryocooler and cryostat, and investigated the flashover discharge and breakdown. The results of this study will be useful as a basic data for electrical insulation design of the HTS system using solid nitrogen as cryogen.

• 한국초전도ㆍ저온공학회논문지
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• 제11권3호
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• pp.26-30
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• 2009

Korea Superconducting Tokamak Advanced Research(KSTAR) device is composed of 30 superconducting magnets, magnet structure, vacuum vessel, cryostat, current feeder system, and etc. KSTAR device is operated in the cryogenic temperature and high magnetic field. We install about 800 sensors - temperature sensors, stain gages, displacement gages, hall sensors - to monitor the thermal, mechanical, electrical status of KSTAR during operation. As a tremendous numbers of sensors should be installed for monitoring the KSTAR device, the method of effective installation was developed. The sensor test was successfully carried out to check its reliability and its reproduction in the cryogenic temperature. The sensor signal is processed by PXI-based DAQ system and communicated with central control system via machine network and is shown by Operator Interface(OPI) display in the main control room. In order to safely operate the device, any violations of mechanical & superconductive characteristic of the device components were informed to its operation system & operator. If the monitored values exceed the pre-set values, the protective action should be taken against the possible damage. In this paper, the system composition, operation criteria, operation result were presented.

• 한국초전도ㆍ저온공학회논문지
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• 제25권2호
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• pp.19-24
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• 2023

Recently, interest in renewable energy such as solar and wind power has increased as an alternative to fossil fuels. Renewable energy sources such as large wind farms require long-distance power transmission because they are located inland or offshore, far from the city where power is required. High-Temperature Superconducting (HTS) power cables have more than 5 times the transmission capacity and less than one-tenth the transmission loss compared to the existing cables of the same size, enabling large-capacity transmission at low voltage. For commercialization of HTS power cables, unmanned operation and long-distance cooling technology of several kilometers is essential, and pressure drop characteristic is important. The cryostat's spiral corrugation tube is easier to bend, but unlike the round tube, the pressure drop cannot be calculated using the Moody chart. In addition, it is more difficult to predict the pressure drop characteristics due to the irregular surface roughness of the binder wound around the cable core. In this paper, a CFD model of a spiral corrugation tube with a core was designed by referring to the water experiments from previous studies. In the four cases geometry, when the surface roughness of the core was 10mm, most errors were 15% and the maximum errors were 23%. These results will be used as a reference for the design of long-distance HTS power cables.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.943-945
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• 2002

This paper presents conceptual design and 3-D electromagnetic analysis of 1MVA transformer with BSCCO-2223 High Tc Superconducting (HTS) tapes. The rated voltages of each sides of the transformer are 22.9 kV and 6.6 kV, and double pancake windings were adopted. High voltage and Low voltage sides were composed of several double pancake windings. Four HTS tapes were wound in parallel for the windings of low voltage side and were transposed in order to distribute the currents equally in each conductor. The transformer core was designed as a shell type core made of laminated silicon steel plates and the core is separated with the windings by a cryostat with Fiberglass Reinforced Plastics(FRP). A sub-cooling system using $LN_2$ were designed to maintain the coolant temperature of 65K. Finally perpendicular components of magnetic field applied to tapes were calculated 0.24T in the rated operation using 3-D analysis. A real 1MVA HTS transformer will be manufactured in near future based on the design parameters presented in this paper.