• 한국가스학회지
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• 제6권1호
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• pp.81-85
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• 2002

탱크와 연결된 배관에서 원하지 않은 사고로 인해 액체 위험물질의 누출이 발생할 경우 천이영역에서의 누출속도 계산방법을 제시하였다. 배관에서의 액누출에 관한 누출속도는 층류와 난류영역에서 Crowl and Louvar 등이 제시한 모델식을 이용하여 프로그램 또는 직접계산에 의해 이루어지고 있으나, 천이영역에 대한 모델식은 없었다. 따라서 본 논문에서는 Lap-Mou Tam 등이 실험한 천이영역에서 레이놀즈수에 따른 마찰계수 실험값을 이용하여 천이영역에 대한 누출속도 값을 계산하였고 이 값을 층류와 난류에 관한 모델식을 사용한 값과의 비교를 통해 천이영역에서 일반적으로 사용할 수 있는 모델식으로 난류에 관한 모델식으로 계산한 값에 안전율 $30\%$를 추가한 값을 위험평가에 사용할 수 있음을 보였다.

• 간호행정학회지
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• 제3권1호
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• pp.93-106
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• 1997

By the increase of the rate of existence of the hemodialyzing patients, they were required the long run treatment. Regardless of medical insurance expansion, hemodialyzing cost much expenses so that hospital has been considering the reuse of hemodialyzer and flowing euqipments along with the diverse study and progress of the ways of hemodialyzing and medical instruments. This study was aimed to provide the basic materials regarding the reuse of hemodialyzer which is used for the patients of chronic renal disease. The reusing program in the artificial kidney center of K hospital has been used for this study from 50 patients aften one year result from Sep. 1995 through Aug. 1996. Automatic equipment of DRS-4 made by Seratronic Co., was used as the equipment and it was retreated with the function test simultaneously. Compliaction and confirmation of the infection were by the records of the hemodialysis of the patients. SPSS was used for the analysis of the materials by computerization. The character of the patients and the rate of removal was by mistake and percentage, function test and rate of complication by Ftest(ANOVA) and the rate of complication per items by ${\chi}^2$ and Ftest. As the post test the Duncan's test was used for the statistically significant different variables in the standard of p<.05 after Ftest. The followings are the summary of the result : 1) In the function test of the new hemodialyzer and the reused one, and in all of CA110 and CF15.11, the dialyzer ultrafiltration coeffient(KUf) was appeared to have been higher in the reusing groups than the first use ones. This has been the normal limit showing no troubles with them. 2) In the function test of the new and reused hemodialyzer, in all of CA110 and CF15.11, the total blood volume was appeared to have been the less value in the reuse groups than the new ones. This was the price within 80% of the first price that both showed possible for use. 3) The result of reuse hemodialyzer of CA110 was $29.48{\pm}7.83$ in average in the test of leak test while $17.3{\pm}7.96$ in reuse of CF15.11. The normal limit of <60 was the leak test result. So both of the hemodialyzer was normal for reuse. 4) The rate of removal of Blood Urea Nitrogen(BUN) was 72.25% in CA110 hemodialyzer by reusing 16-20 times as the highest rate showing the better result in the reuse hemodialyzer, while in CF15.11 hemodialyzer showed 71.16% by highest rate in the first use by the highest rate with no difference from the reuse. 5) The rate of removal of serum creatinine of CA110 was 64.08% by highest rate in reuse of 1-5 times by showing better result in reuse hemodialyzer. While in CF15.11 66.47% the highest by reuse of 16-20 times showing no difference from each other. 6) No patients were admitted or precribed by antibiotics in relation with reuse dialyzer and no reports were shown about hepatitis $B{\cdot}C$. AIDS in fection. 7) Of the total 248 episods of complication due to the hemodialyzing, 86 by first use, 73 by 1-5 times, 35 by 6-10 times, 35 by 11-15 times and 19 by 16-20 times have been shown which have had no significant difference between the groups. 8) In the comparison of the expense for the hemodialyzer, there was the effect of saving 11,597.6 Won between the first and reuse hemodialyzer. And by decreasing the extracted materials, they did the great role of disposing the waste matters.

• 한국진공학회지
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• 제18권6호
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• pp.411-417
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• 2009

차세대 반도체 및 디스플레이 산업용 드라이펌프의 배기속도를 평가하기 위해 최소부피 22 L 급의 정적형 유량계를 설계/제작 하였다. 정적형 유량계의 기본 평가항목인 base pressure와 leak rate 측정결과 각각 $6{\times}10^{-8}\;mbar$ 와 $1.5{\times}10^{-6}\;mbar-L/s$로 측정되었고 throughput limit의 경우 기존 875 L 급보다 1 order 낮은 $1{\times}10^{-3}\;mbar-L/s$ 영역까지 확대되었음이 확인되었다. 구축된 시스템을 이용해 배기용량이 적은 최신 공정 드라이 펌프까지도 배기속도 값을 정확히 측정할 수 있으며, 구축비용이 높은 정압형 유량계를 어느 정도 대체할 수 있을 것으로 기대하고 있다.

• Journal of the Korean Wood Science and Technology
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• 제40권5호
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• pp.319-326
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• 2012

Han-green building is one of the modernized Korean traditional buildings developed by Korea Forest Research Institute. This building was developed to increase the competitiveness of Korean traditional building using state-of-art technologies; hence Han-green building has the inherent characteristics of traditional building such as exposed wood frame in wall. Because of discontinuity in wall by the exposed wood frame, there is a concern on heat-air leaking in terms of energy performance. In this study, air-tightness of Han-green building was evaluated to investigate the influence of gaps between frames and in-fill walls. Blower door test was carried out to evaluate the air-tightness, and air-change rate (ACH50) was evaluated by averaging four set of pressurization and depressurization test. The air-change rate of Han-green house was 5.91 $h^{-1}$. To improve energy performance of Han-green house, thermal infrared images of Han-green house were taken in winter with heating to find out where the heat loss occurred. It was found that the building lost more heat through gaps between frames and in-fill walls rather than through other parts of this building. After covering all the gaps by taping, the blower door test was performed again, and the air-change rate was improved to 5.25 $h^{-1}$. From this analysis, it was concluded that the heated air can leak through the gaps between frames and walls. Therefore, when one designs the post and beam building with exposed frame, the detail design between frame and wall needs to be carefully dealt. However, Han-green building showed relatively high air-tightness comparing with other country research results.

• Journal of Chest Surgery
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• 제28권3호
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• pp.263-267
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• 1995

A total and consecutive 87 patients underwent aortic valve replacement[AVR with the St. Jude Medical prosthesis between 1984 and 1993. Age ranged from 14 to 66 years[mean:38.6$\pm$ 14.0 years .Twenty-one patients [24.1% had undergone previous valve replacement. There were 8 early deaths with an operative mortality rate of 9.2% [7.6% for primary AVR and 14.3 % for re-replacement AVR . Seventy-nine early survivors were,followed for a total of 309.1 patient-years[mean:3.9$\pm$ 2.5 years . A late mortality rate was 5.1% [4 patients or a linearized incidence of 1.294 %/patient-year. All were anticoagulated with coumadin to maintain the international normal ized ratio[INR between 1.5 and 2.5. One patient experienced thromboembolism[0.324%/patient-year , and none did bleeding. Endocarditis occurred in one[0.324%/patient-year . Paravalvular leak was the most frequent complication and was experienced by 8 patients[2.588%/patient-year , and 5 of them required re-replacement AVR[1.618 %/patient year of reoperation rate . There was no structural failure of the prosthesis. Actuarial survival including operative death was 83.9%$\pm$ 4.6% at 10 years.The actuarial estimates of freedom from thromboembolism and of freedom from late death and all complications were 95.1% $\pm$ 4.8 % and 81.4% $\pm$ 6.1%, respectively, at 10 years. These clinical results suggest that less intensive anticoagulation may be allowed for patients of AVR with the St. Jude Medical valve with low incidences of both thromboembolic and bleeding complications.

• Nuclear Engineering and Technology
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• 제23권3호
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• pp.299-305
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• 1991

복수기를 통한 해수유입은 증기발생기내에 부식환경을 조성시키게 한다. 이론적 분석을 통하여 복수기누설시에 해수증의 불순물인 염소가 2차계통내에 누적되는 경향을 영광원전을 모델로하여 평가하였다. 분석결과 해수누설시에 고농도의 염소가 증기발생기내에 누적되는 것으로 나타났으나, 이는 증기 발생기내의 수질을 산성분위 기로 조성시킬 것으로 판단되었다. 복수기의 최대허용 설계누설(0.5 gpm)시에는 증기발생기 취출수량을 최대로 늘리고, 복수기정화계통을 가동하더라도 증기발생기에 2.3 ppm 및 복수기집수정에 0.6 ppm의 염소가 누적되는 것으로 나타났다. 또한 증기발생기에서의 염소농축계수는 아래와 같이 전적으로 취출수량 및 정화계통효율에만 의존하는 것으로 나타났으며,（equation omitted）취출수 및 정화계통은 2차계통내의 불순물을 제거하는데 효과적인 것으로 평가되었다.

• 대한기관식도과학회지
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• 제6권2호
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• pp.159-163
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• 2000

The patient with findings of diffuse infiltrative lung on chest X-ray has various causes; therefore, the prognosis is different and the treatment should be changed according to the cause. We are trying to identify the meaning of operative lung biopsy and to 11nd a more accurate and effective procedure. We reviewed 46 medical records of patients with the findings of diffuse infiltrative lung on chest X-ray who had undergone operative lung biopsy or biopsies for 8 years. The open lung biopsy were done in 22 cases(47.8%) and thoracoscopic lung biopsy in 24 cases(52.2%). There is no significant difference in the rate of diagnosis(p=0.452) and the incidence of complications(p=0.155) between these groups. The number of cases with more than two biopsies are 9(19.6%) and that of one biopsy are 37(80.4%). There are no statistical difference in the rate of diagnosis(p=0.928) and the incidence of complications(p=0.125). The postoperative complications occurred in 8 cases,7 cases of air leak more than 7 days and 1 case of respiratory insufficiency. In the diagnosis and treatment of the patients with findings of infiltrative lung on chest X-ray, the operative lung biopsy is the very necessary course, and shows satisfactory rate of diagnosis with negligible complications.

• 한국수소및신에너지학회논문집
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• 제23권4호
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• pp.316-322
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• 2012

A fuel cell vehicle has the hydrogen detection sensors for checking the hydrogen leakage because it use hydrogen for its fuel and can't use a odorant to protect the fuel cell stack. To verify the hydrogen safety of leakage we select the high possible leak points of fittings in hydrogen storage system and test the leaking behavior at them. The hydrogen leakage flow rate is 10, 40, 118 NL/min and the criterion for maximum hydrogen leakage is based on allowing an equivalent release of combustion energy as permitted by gasoline vehicles in FMVSS301. There are total 18EA hydrogen leakage detection sensors installed in test system. we acquire the hydrogen leakage detection time and determine the ranking. Hydrogen leakage detection time decrease when hydrogen leakage flow rate increase. The minimum hydrogen leakage detection time is about 3 seconds when the flow rate is 118NL/min. In this study, we optimize hydrogen sensor position in fuel cell vehicle and verify the hydrogen leakage safety because there is no inflow inside the vehicle.

• International Journal of Air-Conditioning and Refrigeration
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• 제11권2호
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• pp.51-60
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• 2003

In the nuclear power plant, emergency core coolant system (ECCS) is furnished at reactor coolant system (RCS) in order to cool down high temperature water in case of emergency. However, in this coolant system, thermal stratification phenomenon can occur due to coolant leaking in the check valve. The thermal stratification produces excessive thermal stresses at the pipe wall so as to yield thermal fatigue crack (TFC) accident. In the present study, effects of turbulence penetration on the thermal stratification into T-branches with square cross-section in the modeled ECCS are analysed numerically. Standard k-$\varepsilon$ model is employed to calculate the Reynolds stresses in momentum equations. Results show that the length and strength of thermal stratification are primarily affected by the leak flow rate of coolant and the Reynolds number of duct. Turbulence penetration into the T-branch of ECCS shows two counteracting effects on the thermal stratification. Heat transport by turbulence penetration from main duct to leaking flow region may enhance thermal stratification while the turbulent diffusion may weaken it.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.1953-1958
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• 2007

This paper presents the results of a series of performance tests for the integral Stirling cryocooler. Infrared sensor systems incorporating cryocoolers are required to be qualified to the appropriate environmental specification. Integral Stirling cryocooler for thermal imaging system have matured to the stage of undergoing formal qualification test program. The thermal environmental test of the Stirling cryocooler is presented in this paper. We performed that low and high temperature keeping test from $-40^{\circ}C$ to $+71^{\circ}C$ and operating test at high and low temperature cyclic range with acceptance tests performed at scheduled intervals. Cooldown time to 80K and steady state input power at 80K were determined as a function of cooler components temperatures at the compressor, hot end and cold tip. Tests performed on this cooler have been successful with a measured cooldown time to 80K of less than 5 minutes 24seconds for $71^{\circ}C$ ambient temperature with input power of 11W