• 한국연초학회지
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• 제27권1호
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• pp.114-119
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• 2005

The study was carried out to develope quantitative analysis method of individual sugars in licorice extract. Individual sugars were analyzed by HPLC equipped with Refractive Index(RI) Detector. R values of sucrose and glucose were 1.0000 and R values of fructose and maltose were 0.9999. Standard calibration curve showed good linearity. Detection limit of sugars was in the range of 1.58 to 3.92 ${\mu}g$. Recovery rate of fructose, glucose, sucrose and maltose was $99.4\~102.2\%,\;92.3\~97.9\%,\;99.4\~102.0\%,\;91.1\~101.0$ respectively. Measure uncertainty was calculated to confirm trust and accuracy of analytical results. Main uncertainty factors were standard purity and HPLC replication injection. In $95\%$ trust level expanded uncertainty of sugars in licorice extract were fructose $1.98\pm0.047,\;glucose\;1.32\pm0.065,\;sucrose\;11.69\pm1.177,\;maltose\;1.06\pm0.042\;g/100\;g$.

• Journal of Radiation Protection and Research
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• 제43권4호
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• pp.137-142
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• 2018

Background: Gamma-ray detectors having a thin window of a material with low atomic number can increase the true coincidence summing effects for radionuclides emitting X-rays or gamma-rays. This effect can make efficiency calibration or spectrum analysis more complicated. In this study, a Cu shield was tested as an X-ray filter to neglect the true coincidence summing effect by X-rays and gamma-rays in gamma-ray spectrometry, in order to simplify gamma-ray energy spectrum analysis. Materials and Methods: A Cu shield was designed and applied to an n-type high-purity germanium detector having an $X-{\gamma}$ summing effect during efficiency calibration. This was tested using a commercial, certified mixed gamma-ray source. The feasibility of a Cu shield was evaluated by comparing efficiency calibration results with and without the shield. Results and Discussion: In this study, the thickness of a Cu shield needed to avoid true coincidence summing effects due to $X-{\gamma}$ was tested and determined to be 1 mm, considering the detection efficiency desired for higher energy. As a result, the accuracy of the detection efficiency calibration was improved by more than 13% by reducing $X-{\gamma}$ summing. Conclusion: The $X-{\gamma}$ summing effect should be considered, along with ${\gamma}-{\gamma}$ summing, when a detection efficiency calibration is implemented and appropriate shielding material can be useful for simplifying analysis of the gamma-ray energy spectra.

• 한국미생물·생명공학회지
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• 제20권4호
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• pp.470-476
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• 1992

Nocardia mediterranei NCK-4를 동결건조시 생존도에 미치는 영향을 검토하기 위해 보호물질의 종류와 농도, cell 농도 및 건조시간에 대해 실험한 data를 반응표면분석법을 활용하여 분석한 결과, 추정된 최대치의 생존도는 39.3이었으며, 이 최적 조건은 sucrose 11.6(v/v), cell 농도 $1.16{\times}10^{11}$(CFU/ml), 건조 시간 6.18hrs로 나타났다. N.mdeiterranei NCK-4를 동결건조하여 rehydration한 후 계대배양없이 starter cell로서 발효생산에 사용가능성을 검토한 결과, 전배양시 대조군인 FVM(frozen vegetative mycelium)과 거의 비슷하게 cell의 농도를 맞추어 발효함으로써 가능하다. 따라서 이 starter cell은 lyophilization 후 약 18개월간 저장하여 안정하게 사용할 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집
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• pp.1-6
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• 2004

In this paper author describe the undoped and $Co^{2+}$ (0.5mole%)doped $Cd_4GeS_6$ single crystals were grown by the chemical transporting reaction(CTR) method using high purity(6N) Cd, $GeS_2$, S elements. It was found from the analysis of X-ray diffraction that the undoped and $Co^{2+}$(0.5mole%) doped $Cd_{4}GeS_{6}$ compounds have a monoclinic structure in space grop Cc. The optical energy band gap was direct band gap and temperature dependence of optical energy gap was fitted well to Varshni equation. Impurity optical absorption peaks due to the doped cobalt in the $Cd_4GeS_6:Co^{2+}$ single crystal were observed at 3593cm-1, 5048cm-1, 5901cm-1, 7322cm-1, 12834cm-1, 13250cm-1, 14250cm-1，and 14975cm-1 at 11.3K.

• 분석과학
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• 제18권6호
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• pp.552-558
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• 2005

환경 대기 중에 미량 농도로 존재하는 악취 물질의 측정을 위한 ppm 수준의 다이메틸설파이드($(CH_3)_2S$) 가스 인증표준물질(CRM)을 개발하였다. 이 표준가스는 $(CH_3)_2S$의 농도 수준이 10 umol/mol이고 질소압력이 1500 psi로서, 알루미늄 실린더에 제조되었고, 3년 동안에 0.2% 수준의 안정성을 보였다. 동시에 제조된 표준가스 실린더 4병의 $(CH_3)_2S$ 농도를 가스크로마토그래프-불꽃이온화검출기(GC-FID)로 비교하여 0.4% 수준의 제조 재현성과 0.25%의 중량 및 순도의 표준불확도를 확인하였다. 개발된 $(CH_3)_2S$표준가스의 인증값은 10 umol/mol 수준이었고, 순도, 혼합. 제조, 분석, 흡착성 및 안정성을 모두 고려하여 결정한 인증값의 상대 확장불확도는 1.1%(95%의 신뢰수준, k=2)이었다.

• 분석과학
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• 제19권6호
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• pp.498-503
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• 2006

환경 대기 중에 미량 농도로 존재하는 악취 물질의 측정을 위한 ppm 수준의 다이메틸다이설파이드($(CH_3)_2S_2$) 가스 인증표준물질(CRM)을 개발하였다. 이 표준가스는 $(CH_3)_2S_2$의 농도 수준이 $10{\mu}mol/mol$이고 질소압력이 1500 psi로서, 알루미늄 실린더에 제조되었고, 2년 동안에 0.14% 수준의 안정성을 보였다. 동시에 제조된 표준가스 실린더 4병의 $(CH_3)_2S_2$ 농도를 가스크로마토그래프-불꽃이온화검출기(GC-FID)로 비교하여 0.4% 수준의 제조 재현성과 0.25%의 중량 및 순도의 표준불확도를 확인하였다. 개발된 $(CH_3)_2S_2$ 표준가스의 인증값은 $10{\mu}mol/mol$ 수준이었고, 순도, 혼합. 제조, 분석, 흡착성 및 안정성을 모두 고려하여 결정한 인증값의 상대 확장불확도는 1.01%(95%의 신뢰수준, k=2)이었다.

• 한국결정성장학회지
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• 제4권3호
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• pp.315-324
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• 1994

고순도 규사 원료를 열처리하는 경우, 불순물로 포함되어 있는 미량성분이 quartz의 전이과정에 미치는 영향 및 전이 경로에 대하여 조사하였다. 미량성분의 영향을 조사한 결과, 규사 중의 미량성분 함량이 많아지면 cristobalite 생성량은 많아지며, quartz의 소멸온도 및 cristobalite의 생성온도는 낮아졌다. quartz의 전이경로를 조사한 결과 quartz $\rightarrow$ 천이비정질상 $\rightarrow$ melt (T) 및 quartz $\rightarrow$ 천이비정질상 $\rightarrow$ cristobalite $\rightarrow$ melt (C)의 경로가 항상 공존하며, 미량성분이 적은 경우는 T 경로가 우세하지만, 미량성분이 많은 경우는 C 경로가 우세한 것으로 규명되었다. 또한 XRD를 이용한 결정질 함량의 분석 결과로 부터 계산한 밀도와 pycnometer로 측정한 밀도를 비교한 결과 서로 일치하였다. 규사를 용융하여 석영유리를 제조하는 경우,특정온도에서 규사의 팽창 정도를 유추할 수 있을 것이다.

• 한국수소및신에너지학회논문집
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• 제28권4호
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• pp.352-360
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• 2017

Polygeneration process is widely used to pursuit high efficiency by sharing electricity, utility, refrigeration and the utilization of product chemicals. In this paper, performance analysis of the 450 MW Class polygeneration process was conducted with various syngas generated from coal and biomass gasifier. WGSR and PSA process were employed for hydrogen production and separation. Process modeling and dynamic simulation was carried out, and the results were compared with NETL report. Net power of the polygeneration process was 439 MW considering power consumption. More than 90% of CO was converted at WGSR and the hydrogen purity of PSA was more than 99.99%.

• Journal of Ginseng Research
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• 제22권4호
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• pp.284-288
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• 1998

This study was carried out to establish a new efficient method for isolation and purification of ginsenosides. Silica gel column chromatography, having been used for the isolation of ginsenosides, is advantageous to obtain a large amount of ginsenosides. However, it has a disadvantage to isolate ginsenosides to their highest purity. In addition, normal-or reverse-phase HPLC method thus far reported is confined to quantitative analysis. Especially, it has not been possible to isolate racemic 20(S)- and 20(R)-ginsenoside Rg2. In this experiment, isolation and purification of ginsenosides were accomplished by Diaion HP-20 adsorption chromatography, silica gel column chromatography, recrystalization and Prep. HPLC with or without Prep. TLC. From this study, we could establish a new efficient method for isolation and purification of 9 major and/or minor ginsenosides.

• 성인간호학회지
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• 제18권2호
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• pp.272-283
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• 2006

Purpose: This research was done to explore the meaning of 'well-being' as experienced by middle aged people. Method: The data were collected by individual in-depth interviews with 107 middle aged adults and it was analysed using qualitative content analysis. Results: 4 components of the meaning of well-being as perceived by the participants were identified as follows: the life of free without physical discomfort and psychosocial distress; the life of comfort with plenty of time, space, material, and mind; the life of purity with natural material and honest mind; the life of harmony with extended consciousness. Conclusion: Therefore the identified meanings of the well-being in this study should be reflected to the nursing education and the nursing practice.