• 한국초전도ㆍ저온공학회논문지
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• 제4권2호
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• pp.73-77
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• 2002

In order to derive the detailed design of Thermal Shield Cryopanel. which plays a role to make the Tokamak Nuclear Fusion Equipment work at both static and efficient conditions the commercially available software package FLUENT Version 5.3, was utilized. This study investigated the effects of thermal sources and distributions on the temperatures of Lid. Body. Base. and EH-Port Cryopanel by the numerical technique whose grid generations cover the solid and 9as region of the panel. The physical model of the Thermal Shield Cryopanel is that the 10mm diameter of the pipe with 1mm thickness is soldered on the Stainless steel Panel with 4mm thickness. The heat fluxes to the panel are assumed to be by thermal radiation in the vacuum space and by conduction through the supporters. The inlet conditions of Helium gas are 20 atmospheric Pressures and 60K temperature. The panel shapes with cooling Pipes and the operational conditions to keep appropriate temperature distribution of Thermal Shield Cryopanel Have been found and suggested.

• 한국추진공학회지
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• 제9권3호
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• pp.66-73
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• 2005

액체로켓 추진시스템에서 가압시스템은 발사체 추진제 탱크의 얼리지 공간에 제어된 가스를 공급하는 것이다. 가압시스템에서 고온 가스 열교환기를 적용하는 데는 가압제의 비체적을 증가시켜 전체 발사체 시스템의 중량을 감소시키는 장점이 있다. 가압시스템 성능에 있어서 주목할 만한 개선점은 극저온 시스템에서 얻어질 수 있다. 이러한 경우 가스 공급은 극저온 탱크 내부에 저장되어 진다. 본 연구에서는 극저온 추진제를 모의(模擬)하기 위하여 액체 질소를 사용하였다. 극저온 가압제의 온도 특성은 가압시스템에서 구성 단품을 개발하는데 있어서 매우 중요하다. 본 연구에서는 SINDA/FLUINT를 이용한 이론적 해석과 PTF에서 수행된 실험 결과에 대하여 비교 분석이 수행되었다.

• 천문학회보
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• 제38권1호
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• pp.49.1-49.1
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• 2013

We have been carrying out near-infrared (NIR) spectroscopy as well as [Fe II] narrow band imaging observations of Cassiopeia A supernova remnant (SNR). In this presentation, we describe the spectral classification of the iron knots around the SNR. From eight long-slit spectroscopic observations for the iron-bright shell, we identified a total of 61 iron knots making use of a clump-finding algorithm, and performed principal component analysis in an attempt to spectrally classify the iron knots. Three major components have emerged from the analysis; (1) Iron-rich, (2) Helium-rich, and (3) Sulfur-rich groups. The Helium-rich knots have low radial velocities (${\mid}v_r{\mid}$ < 100 km/s) and radiate strong He I and [Fe II] lines, that match well with Quasi-Stationary Flocculi (QSFs) of circumstellar medium, while the Sulfur-rich knots show strong lines of oxygen burning materials with large radial velocity up to +2000 km/s, which imply that they are supernova ejecta (i.e. Fast-Moving Knots). The Iron-rich knots have intermediate characteristics; large velocity with QSF-like spectra. We suggest that the Iron-rich knots are missing "pure" iron materials ejected from the inner most region of the progenitor and now encountering the reverse shock.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.229-231
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• 1999

For the first time in Korea, a 30kVA superconducting generator has been designed, developed and successfully tested recently. This is the forerunner of a 1MVA superconducting generator which is currently under development. The paper discusses the structure and manufacturing of a superconducting generator. Helium transfer coupling has 3 passages of the recovered Helium gas and a gas flow control system.

• Korean Membrane Journal
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• 제3권1호
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• pp.39-50
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• 2001

The counter-diffusion of two gaseous substances permeating a polymeric membrane has been investigated both experimentally and theoretically. The aim of the study was to find mutual effects, if any, that could influence the permeability and diffusivity data. The experimental data were obtained with an isostatic permeameter operating at ambient pressure and 303 K: helium, nitrogen, carbon dioxide methane were used as permeating gas at different partial pressure; helium or nitrogen as equilibrating or carrier gas. No evident mutual effect of the counter-diffusing gas was observed. The theoretical analysis gave some insight into the phenomena and it was concluded that at near-atmospheric pressures, and in the absence of swelling phenomena no mutual interaction exists. On a theoretical basis any mutual interaction between diffusing and counter-diffusing gases could only occur: i) at high pressures , when the free movement of permeating gas molecules within the polymer is hindered by the counter-diffusing gas; ii) when a large part of the free volume fraction is occupied by the counter--diffusing gas; iii) swelling phenomena modify the structure and free volume fraction of the polymer.

• 천문학회지
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• 제42권3호
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• pp.47-54
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• 2009

In this paper we present an independent FORTRAN code for calculating LTE-plane-parallel model atmospheres. The transfer equation has been solved using Avrett and Loeser method. It is shown that, using an approximate non-gray temperature distribution together with the iteration factors method (Simonneau and Crivellari) for correcting the temperature distribution reduce the number of iteration required to achieve the condition of radiative equilibrium. Preliminary results for pure helium model atmospheres are presented.

• Journal of Magnetics
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• 제3권3호
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• pp.86-88
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• 1998

A portable RF HTS SQUID-based susceptometer was used for small size magnetized sample testing in weak DC (up to 200A/m) and AC (up to 4 A/m) magnetic fields. The system resolution for the magnetic moment is of the order of $1.6{\times}10^{-10} A.m^2$. The measured DC susceptibility of a tested sample agrees well with the value obtained by using a commercial liquid helium susceptometer.

• 한국식품과학회지
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• 제43권4호
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• pp.513-517
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• 2011

PS 필름에 접종된 S. Typhimurium, E. coli O157:H7, L. monocytogenes를 저해시킬 때 헬륨을 사용한 플라즈마 처리의 경우에는 S. Typhimurium이, 헬륨과 산소를 동시에 사용한 플라즈마 처리의 경우에는 L. monocytogenes가 가장 많이 저해되었다. E. coli O157:H7과 L. monocytogenes는 헬륨과 산소를 함께 사용하여 플라즈마 처리하였을 때 헬륨만 사용하였을 때보다 더 큰 저해를 보였다. 헬륨과 산소를 함께 사용한 비열 플라즈마 처리는 L. monocytogenes가 소시지 케이싱이나 훈제연어에 감염되었을 때보다 PS 필름에 감염되었을 때 L. monocytogenes를 더 효과적으로 저해시켜 감염된 재료에 따라 다른 저해 효과를 보여 주었다. 비열 플라즈마 처리에 사용된 가스의 종류와 미생물이 감염된 재료는 그 처리의 항균 효과에 대한 평가에서 중요하게 고려되어야 할 것이다. 헬륨과 산소를 사용한 비열 플라즈마 처리는 공정 후 포장재에 감염된 L. monocytogenes를 효과적으로 저해할 수 있을 것으로 기대된다.

• The Journal of Korean Physical Therapy
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• 제12권3호
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• pp.287-292
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• 2000

This studies were to investigate the effects of low power wavelengths Helium-Neon Infra-Red(He-Ne 1R) laser on the changes of the serum immunoblobulin(Ig) concentrations in bum rats, The thirty Spraque-Dawley adult male rats were assigned to the 5 groups: the experimental groups(3). the bum control group(1) and the control group(1). There was made three degree burn by the 290 mW IR on the back oreach rats, from 3 days after being burned. the experimental laser groups were irradiated low power wavelengths(292Hz- 1168Hz, 4672Hz) He-Ne IR laser far 5 minutes every day during the 7days. The results were as follows; 1. The concentrations of immunoglobulin G(Ig G) in serum of all experimental groups on the treated with the low power wavelengths of the He-Ne IR laser during the 5 minutes far 7 days were significantly lower than those of bum groups, but those 1168 Hz group were significantly higher than those of the 292 Hz and 4672 Hz groups. 2. There were significantly decreased the change of the level of immunoglobulin M(Ig M) in serum of all experimental groups on the treated with 5 minutes laser fer 7 days to the burn control group. and were significantly increased on treated with more higher wavelengths groups to those of lower groups. 3. The concentrations immunoglobulin E(Ig E) in serum of the 292Hz wavelengths groups were significantly lower than those in bum control group. As above results. the changes of the immunoglobulin in serum levels on the healing process have meaningful effected with the low power wavelengths role on the treated with He-Ne IR laser.

• 대한화학회지
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• 제44권6호
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• pp.573-580
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• 2000

MPT는 최근에 개발된 마이크로파 플라즈마로서 수용매에 강하다. 여러 가지의 변형된 형태의 MPT를 개발하여 구조에 따른 플라즈마의 방전되는 형태를 조사한 결과 이중관 토치는 플라즈마 기체를 적게 소모하며 쉽게 플라즈마가 형성되었으나 토치의 끝이 높은 온도에 견디지 못하고 쉽게 상했다. ICP토치와 같은 형태의 삼중관 토치에 석영관을 중심관으로 사용할 때 가장 안정되고 대칭적인 플라즈마를 형성할 수 있었다. 바탕선을 조사해 본 결과 He MPT는 대기 중으로 돌출되어 대기와 많이 혼합되고 질소에 의해 quenching되는 것으로 보여진다. Membrane desolvator를 탈용매화 장치로 사용하여 헬륨 MPT의 감도를 조사해 본 결과 아르곤 MPT와 비교할 때 대부분의 원소에 대해 검출한계가 10배 이상 높았다. 그러나 여기 에너지가 높은 원소는 비교적 효율적으로 검출할 수 있었다. 헬륨 마이크로파 플라즈마는 적은 양의 플라즈마 기체만 필요하여(약 1.6 L/min) 경제적이며 매우 안정된 형태를 보여주었다. 플라즈마의 분광특성을 조사한 결과 들뜸온도 4950K, 전자밀도 $3.28{\times}10^{14}cm^{-3}$로 측정되었다.