• 설비공학논문집
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• 제20권9호
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• pp.590-598
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• 2008

In this study, performance of R170/R290 mixtures is measured on a heat pump bench tester in an attempt to substitute R22. The bench tester is equipped with a commercial hermetic rotary compressor providing a nominal capacity of 3.5kW. All tests are conducted under the summer cooling and winter heating conditions of $7/45^{\circ}C$ and $-7/41^{\circ}C$ in the evaporator and condenser respectively. During the tests, the composition of R170 is varied from 0 to 10% with an interval of 2%. Test results show that the coefficient of performance (COP) and capacity of R290 are up to 15.4% higher and 7.5% lower than those of R22 for both conditions respectively. For R170/R290 mixture, the COP decreases and the capacity increases with an increase in the amount of R170. The mixture of 4%R170/96%R290 shows the similar capacity and COP as those of R22. For the mixture, the compressor discharge temperature is $16{\sim}30^{\circ}C$ lower than that of R22. There is no problem with mineral oil since the mixture is mainly composed of hydrocarbons. The amount of charge is reduced up to 58% as compared to R22. Overall, R170/R290 mixture is a good long term 'drop-in' candidate to replace R22 in residential air-conditioners and heat pumps.

• 동력기계공학회지
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• 제20권5호
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• pp.78-85
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• 2016

This paper considers the influence of internal heat exchangers to the efficiency of a refrigerating system using R170. These liquid-gas heat exchangers(internal or suction-line heat exchangers) can, in some cases, yield improved system performance while in other cases they degrade system performance. A steady state mathematical model is used to analysis the performance characteristics of refrigeration system with internal heat exchanger. The influence of operating conditions, such as the mass flowrate of R170, inner diameter tube and length of internal heat exchanger, to optimal dimensions of the heat exchanger is also analyzed in the paper. The main results were summarized as follows : the mass flowrate of R170, inner diameter tube and length of internal heat exchanger, and effectiveness have an effect on the cooling capacity, compressor work and RCI(Relative Capacity Index) of this system. Exception for the effect of inner diameter, the RCI of R170 with respect to refrigerant mass flowrate, the length and effectiveness of internal heat exchanger is about 2.1~3.3% higher than that of R13 at the same experimental conditions. With a thorough grasp of these effect, it is necessary to design the R170 compression refrigeration cycle using internal heat exchanger.

• 동력기계공학회지
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• 제11권4호
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• pp.50-55
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• 2007

Nowadays, demands on super low temperature condition for industrial and commercial uses are thriving. Considering of its wide application in the present and the future, study of the super-low temperature refrigeration system should be actively carried out. This study is aimed to investigate refrigeration capacity and coefficient of performance(COP) of the cascade refrigeration system, as well as to get the system which can reach evaporator temperature of $-70^{\circ}C$. For this purpose, R290 and R170 are charged in high stage and low stage respectively. Finally the characteristics of system using R290 and R170 will be proposed. Additionally, In this experiment, the flow rate of air flowing through the LS evaporator and the compressor inlet pressure were varied to investigate the refrigeration capacity and coefficient of performance characteristics.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2006년도 The 5th Biannual Meeting of Pacific Rim Society for Fertility and Sterility
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• pp.170.2-170.2
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• 2006

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.414-420
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• 2005

For supporting future demands of lower temperature. environmental friendly low- temperature refrigerants must be studied and developed to replace halocarbon. Ethane. which is one of hydrocarbon compound. is an environmental friendly refrigerant because it has zero ODP and GWP ${\sim}$ 20[per 100yr]. On this study, two-stage cascade refrigeration system was utilized to investigate performance of ethane on the low-stage. By employing R22 at higher stages. energetic performance as well as operating condition of R22/R170 system is compared to R22/R23. At low stage evaporation pressure ranges from 1.10 to 2.74 bar, R22/R170 shows higher COP over R22/R23. Furthermore, at the same range evaporation temperature R22/R170 can reach lower temperature.

• 한국항행학회논문지
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• 제23권5호
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• pp.444-451
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• 2019

본 논문에서는 항공기 탑재장비의 RS-170a 영상 신호에 대한 EMI 및 낙뢰 간접영향에 대한 보호 대책을 설명한다. 항공기 탑재장비는 외부 환경으로부터 발생하는 전자파 간섭과 항공기 낙뢰 피격시 발생하는 낙뢰 간접영향으로 부터 발생하는 서지 전압에 의해 장비의 오작동이나 물리적 손상의 위험에 노출되어있다. 이러한 위험으로부터 장비를 보호하기 위해서는 전자파 간섭 및 간접 낙뢰 효과에 대한 보호 설계를 장비에 적용해야 하는데, 신호의 전압이 낮고 주파수 대역이 높을수록 보호 회로에 의한 신호 왜곡이 문제가 된다. 따라서 본 논문에서는 EMI 및 낙뢰 간접영향에 대한 일반적인 보호 설계 방법과, RS-170a 신호를 기준으로 보호 설계 적용에 따른 영상 신호 왜곡 현상을 최소화하기 위한 고려 사항을 소개한다. 그리고 이 과정에서 논한 고려 사항을 적용해 실제 장비 설계를 개선한 사례를 소개한다.

• 미생물학회지
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• 제54권2호
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• pp.167-168
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• 2018

Staphylococcus xylosus는 일반적으로 포유동물의 피부에 존재하며 식품가공설비와 의료기기 등에서도 발견이 보고되었다. 본 연구에서는 강력한 생물막 생성 특성을 가지는 Staphylococcus xylosus S170의 전체 유전체 서열을 분석하여 보고한다. 이 유전체는 2,910,005 bp 크기, 2,674개의 단백질 코딩 서열과 22개의 rRNA, 57개의 tRNA유전자를 포함한다. 본 연구에서 제공하는 유전체 정보는 생물막 관련 유전자 분석으로 생물막 형성 기작을 좀 더 잘 이해하는데 도움이 될 수 있다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2005년도 추계학술발표회 및 workshop
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• pp.170-170
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• 2005

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1324-1325
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• 2008

근래 선진 중전기 메이커에서는 차단기, GIS 등의 전통적인 단품 위주에서 탈피하여 전력 IT 기술을 접목한 전력기기/변전소 자동화를 강력하게 추진하고 있다. 특히 전체 변전소를 감시, 제어, 계측, 보호할 수 있도록 전력 IT 기술을 기반으로 한 IEC 61850 적용 변전소 종합 자동화 시스템 개발에 역량을 집중하고 있다. 본 논문에서는 당사에서 개발한 최신 IT 기술을 적용한 IEC 61850 기반 170㎸ GIS용 Bay Controller 관련 구성, 기능, 성능시험 결과에 대해 기술하며, 변전소 내 노이즈로 인해 유발될 수 있는 전자장치 오동작 등을 보증하기 위해 실시한 전자파 장해시험 결과와 GIS와 동일한 환경에 설치되므로 온/습도, 진동/충격시험을 관련 국제규격인 IEC 60255-6, IEC 60255-21-1, 2, 3에 의거하여 실시한 내용을 기술하도록 한다.

• 설비공학논문집
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• 제18권4호
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• pp.312-319
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• 2006

In this study, performance of 2 pure hydrocarbons and 7 mixtures was measured in an attempt to substitute HCFC22 used in air-conditioners and heat pumps. The mixtures were composed of R1270 (propylene), R290 (propane), HFC152a, and RE170 (Dimethyl ether, DME). The pure and mixed refrigerants tested have GWPs of $3{\sim}58$ as compared to that of $CO_2$ and the mixtures are all near-azeotropic showing the gliding temperature difference (GTD) of less than $0.6^{\circ}C$. Thermodynamic cycle analysis was carried out to determine the optimum compositions and actual tests were performed in a laboratory heat pump test bench at the evaporation and condensation temperatures of 7.5 and $45.1^{\circ}C$ respectively. Test results show that the coefficient of performance (COP) of these mixtures is up to 5.7% higher than that of HCFC22. While propane showed 11.5% reduction in capacity, most of the fluids tested had the similar capacity to that of HCFC22. Compressor discharge temperatures were reduced by $11{\sim}17^{\circ}C$ with these fluids. There was no problem with mineral oil since the mixtures were mainly composed of hydrocarbons. The amount of charge was reduced up to 55% as compared to HCFC22. Overall, these fluids provide good performance with reasonable energy savings without any environmental problem and thus can be used as long term alternatives for. residential air-conditioning and heat pumping application.