• 설비공학논문집
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• 제21권3호
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• pp.167-175
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• 2009

In this study, condensation heat transfer coefficients(HTCs) of R22, R123, R134a and R245fa are measured on both 26fpi low fin and Turbo-C tubes. All data are taken at the vapor temperature of $39^{\circ}C$ with a wall subcooling of $3{\sim}8^{\circ}C$. Test results show that HTCs of the newly developed low vapor pressure alternative refrigerant, R245fa, are $7.8{\sim}9.2%$ and $10.3{\sim}18.6%$ higher than those of R123 for 26fpi low fin tube and Turbo-C tube respectively. For all refrigerants tested, HTCs of Turbo-C enhanced tube are higher than those of 26fpi low fin tube. For the low fin tube, Beatty and Katz's prediction equation yielded 20% deviation for all fluids. The heat transfer enhancement ratio of R245fa on the Turbo-C tube is $5.9{\sim}6.4$ while that of R123 is $5.7{\sim}5.9$. From the view point of environmental safety and condensation heat transfer, R245fa is a long term candidate to replace R123 currently used in centrifugal chillers.

• 대한지역사회영양학회:학술대회논문집
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• 대한지역사회영양학회 2004년도 추계학술대회
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• pp.123-123
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• 2004

• 대한설비공학회지:설비저널
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• 제28권5호
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• pp.368-374
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• 1999

최근 세계적으로 환경보호에 대한 관심이 고조됨에 따라 기술개발 방향이 환경을 고려한 규정 및 장치에 제한을 받고 있다. 따라서 냉동 공조 기기에 사용되는 기존의 CFC계열 냉매가 오존층 파괴의 주 원임이 판명됨에 따라 환경 문제가 없는 HCFC계열인 R123와 HFC R134a로의 대체가 불가피하게 되었다.

• International Journal of Air-Conditioning and Refrigeration
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• 제8권2호
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• pp.23-28
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• 2000

In this study, pool boiling performance of a structured enhanced tube for a flooded refrigerant evaporator was experimentally investigated. Tests were performed for three different refrigerants(R-11, R-123, R-l34a). Compared with the heat transfer coefficients of the smooth tube, the heat transfer coefficients of the enhanced tube were 6.6 times larger for R-11, 6.0 times larger for R-123 and 3.5 times larger for R-l34a, which are comparable with the performance of foreign products. The heat transfer coefficients of R-l34a was higher than those of R-11 or R-123, both for the enhanced tube and for the smooth tube. At 4.4$^\circ$C saturation temperature, however, the heat transfer coefficients of R-l34a was approximately the same as those of R-11. The effect of the saturation pressure on the boiling performance was similar to that of the smooth tube-the heat transfer coefficient increased as the saturation pressure increased.

• 설비공학논문집
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• 제11권6호
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• pp.808-814
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• 1999

Pool boiling performance of a metal-formed enhanced tube for a flooded refrigerant evaporator was experimentally investigated. Tests were performed for three different refrigerants(R-11, R-123, R-l34a), at two different saturation temperatures $4.4^{\circ}C \;and \;26.7^{\circ}C$ .Heat flux was varied from 10㎾/$m^2\;to\ 50㎾/$m^2$. Compared with the heat transfer coefficients of the smooth tube, the heat transfer coefficients of the enhanced tube were 6.6 times higher for R-11, 6.0 tines higher for R-123 and 3.5 times higher for R-l34a. The enhancements are comparable with those of foreign products. The heat transfer coefficients of R-l34a were higher than those of R-11 and R-123, either for the enhanced tube or for the smooth tube. At $4.4^{\circ}Csaturation temperature, however, the heat transfer coefficients of R-l34a were approximately the same as those of R-11, The effect of the saturation pressure on the boiling performance was similar to that of the smooth tube - the heat transfer coefficient increases as the saturation pressure increases.

• 한국영양학회:학술대회논문집
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• 한국영양학회 2003년도 연합학술대회
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• pp.123.1-123.1
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• 2003

• 한국영양학회:학술대회논문집
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• 한국영양학회 2003년도 연합학술대회
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• pp.123.2-123.2
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• 2003

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.123.1-123.1
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• 2002

• 미생물학회지
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• 제47권1호
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• pp.97-101
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• 2011

새로운 항진균성물질을 분리할 목적으로 지의류은행에서 107종의 지의류 내생 곰팡이를 분양받아 이들의 항진균성 활성을 조사하였다. Candida albicans를 이용한 항진균 활성검사에서 2종류의 지의류 내생 곰팡이 EL123과 EL156을 최종적으로 선별하였다. 이들은 MYA 배지와 EMM 배지에서 공통적으로 높은 곰팡이 성장저해능을 보였다. 지의류 내생 곰팡이의 5.8S rRNA를 포함하고 있는 internal transcribed spacer 부분을 PCR 증폭 후 nucleotide sequence 분석 및 NCBI Blast 분석 결과 EL123 (JF714250)은 Thielavia microspora와 염기서열이 95%의 유사도를 보였고, EL156 (JF714251)은 Cryptosporiopsis diversispora와 99%의 유사도를 보였으며, 2종 모두 자낭균류(ascomycetes)에 속하였다. 형태적 특성으로는 EL123은 가지 친 형태의 균사가 관찰되었고, EL156은 직선형의 균사가 관찰되었으며, EL156이 EL123보다 액체배양 중에 많은 양의 항진균성 물질을 생성하였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.123-123
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• 2005