• 분석과학
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• 제17권5호
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• pp.438-442
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• 2004

To determine the contents of $^{99}Tc$ in the spent PWR (pressurized water reactor) nuclear fuels by ICP-MS (inductively coupled plasma-mass spectrometry), a technetium separation method using an extraction chromatographic resin (TEVA Spec resin) has been established. $^{99}Tc$ was separated from a spent PWR nuclear fuel solution by this separation procedure and its concentration was determined by ICP-MS. The result agrees well with the value calculated by the program ORIGEN 2 and also the value measured by AG MP-1 resin/ICP-MS method described in our previous paper. It can be concluded that the present separation procedure is superior to the AG MP-1 resin procedure with respect to the time required for technetium separation as well as the efficiency of decontamination from other radioactive nuclides.

• 대한관절경학회지
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• 제9권2호
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• pp.214-217
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• 2005

슬관절의 반월상 연골 낭종은 흔하지 않은 병소로 내측보다는 외측 반월상 연골에 더 흔하게 발생하며, 대개 반월상 연골의 수평파열과 동반되어 있다. 본 증례는 특별한 외상력 없이 내측 반월상 연골의 퇴행성 변화와 후 외측부에 종 파열 및 후각부의 횡파열과 동반된 독립된 2개의 반월상 연골 낭종을 가진 24세 남자 환자로, 관절경을 이용한 낭종 감압술과 반월상 연골 봉합술로 치료하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제25권6호
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• pp.1220-1227
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• 2001

The condensation pressure drop fur refrigerant R-22 flowing in the plate and shell heat exchanger were investigated experimentally in this study. Two vertical counterflow channels were formed in the exchanger by three plates of commercial geometry with a corrugated trapezoid shape of a chevron angel of $45^{\circ}$. The condensing R-22 flowing down in one channel exchanges heat with the cold water flowing up in the other channel. The effects of the mean vapor quality, mass flux, average imposed heat flux and system pressure of R-22 on the pressure drop were explored in detail. The quality change of R-22 between the inlet and outlet of the refrigerant channel ranges from 0.03 to 0.05. The present data showed that pressure drop increases with the vapor quality. At a higher mass flux, pressure drop is higher for the entire range of the vapor quality. Also, a rise in the average imposed heat flux causes an slight increase in the Pressure drop. Finally, at a higher system pressure the pressure drop is found to be slightly lower. Correlation is also provided for the measured pressure drops in terms of the friction factor.

• Journal of Advanced Marine Engineering and Technology
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• 제27권1호
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• pp.108-116
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• 2003

In this paper, the experimental results of condensation heat transfer were reported for the plate and shell heat exchangers(P&SHE) using R-l34a. An experimental refrigerant loop has been established to measure the condensation heat transfer coefficient of R-l34a in a vertical P&SHE. Two vertical counter flow channels were formed in the P&SHE by three plates of geometry with a corrugated trapezoid shape of a chevron angle of 45$^{\circ}$. Downflow of the condensing R-l34a in one channel releases heat to the cold up flow of water in the other channel. The effect of the refrigerant mass flux, average heat flux, system pressure and vapor quality of R-l34a on the measured data were explored in detail. The results indicate that at a higher vapor quality the condensation heat transfer coefficients are significantly higher. Condensation heat transfer coefficients were increased when the refrigerant mass flux was increased. A rise in the average heat flux causes an slight increase in the hr. Finally, at a higher system pressure the hr is found to be lower. Correlation is also provided for the measured heat transfer coefficients in terms of the Nusselt number.

• 한국미생물·생명공학회지
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• 제27권6호
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• pp.440-445
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• 1999

In order to investigate structure-antibiotic activity relationships of brevinin-1 and thanatin containing Rana box composed of basic loop formed by disulfide bridge in their arboxy terminus, thanatin, brevinin 1 and their analogues (T-B1, T-B2 and B-T) in which their Rana box sequence exchanged was designed and synthesized by the solid phase method using Fmoc-chemistry. The basic sequence of Rana box of thanatin had more significant effect on both antibacterial and antifungal activity than that of brevinin 1. The tail sequence (QRM) of thanatin was found to be important in its antibacterial and antifungal activity. Rana box sequence of brevinin-1 did not have a significant effect on its antitumor and phospholipid vesicle-aggregating activities. Brevinin-1 showed stronger $\alpha$-helical structure in the membrane-mimicking environment such as SDS micelle than thanatin. A remarkable increase in a-helicity of bervinin-1 plays more important role in antibiotic activity than that of thanatin. Furthermore, antibacterial activity of thanatin against E. coli resulted from the disruptive effect against the outer cell membrane of E. coli.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.451-454
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• 2011

수중에서 추진되는 초고속 로켓 모터에 적용이 가능한 해수반응 금속연료 (Hydro-Reactive metal Fuel, 이하 HRF) 추진제는 연료의 적재량을 증가시키기 위해 채용하는 추진제이다. 하지만, 현재까지 HRF 추진제에 대한 연소속도 측정 기술 개발에 대한 연구는 미비한 상태이다. 본 연구팀은 연소 속도를 측정하는 기법들 중, 한 번의 실험으로 압력 변화에 따른 연소속도 측정이 가능한 초음파 법을 개발하여 고체 추진제의 연소속도를 측정하고 신뢰성을 검증하였다. 본 논문에서는 기 개발된 시스템을 이용하여 HRF 추진제의 연소 속도를 측정하였다.

• 대한화학회지
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• 제32권1호
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• pp.15-21
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• 1988

반양성자성 용매인 아세토니트릴 중에서 1-(2-thiazolylazo)-2-naphthol (이하 TAN으로 줄임)의 폴라로그래프적 성질을 조사하였다. 직류폴라로그램으로부터 환원전류의 유형과 양성자 주게 인물의 첨가에 따른 영향을 검토하였다. 그리고 환원반응에 관여한 전자수는 정전위분해법으로 구하였다. 또 일정전위전해생성물의 UV-Vis Spectrum과 IR-Spectrum으로부터 전해생성물을 확인하였다. 이상의 실험결과로부터 아세토니트릴 용매중에서 TAN은 1전자 4단계의 환원과정을 거쳐 최종적으로 아민화합물이 됨을 알았다. 또 각 환원과정은 모두 가역적이었으며, 각 단계의 환원전류는 확산지배적이었다.

• 대한골관절종양학회지
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• 제9권2호
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• pp.206-211
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• 2003

수장족저 농포증은 특별한 골, 관절계 질환과 관련이 있을 수 있다. 초기 전흉벽에 국한되었던 이러한 질환은 이후 말초 골, 관절계를 침범하는 것으로 밝혀졌다. 무균성 가감염성 골, 관절 질환 역시 심한 여드름과 관련이 있는 것으로 밝혀졌다. 1987년 Kahn 등은 과거 25년간 발표된 특별한 골, 관절 그리고 피부병변에 관한 수많은 보고들을 기술하기 위하여 약성어를 제시하였다. SAPHO 증후군은 Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis syndrome을 뜻한다. 저자들은 SAPHO 증후군으로 의심되는 과골증을 동반한 좌측 쇄골 및 우측 천장 관절 동통과 수장 농포증이 있는 27세 여자 환자 1예를 경험하였기에 보고하고자 한다.

• 대한기계학회논문집A
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• 제33권4호
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• pp.321-328
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• 2009

Shock absorption performances of various rubbers were investigated by using drop impact test. Several types of rubber such as NR, NBR, EPDM, SR and PUR with three respective levels of shore hardness were used for the test. As in the cases, the absorbed impact energies in rubbers were measured under seven different loads against impact energy between 5-80J. The impact absorption efficiencies of the rubbers then were evaluated by means of both single impact energy condition and summation of all impact energy applied condition. As shown in the results, PUR and EPDM have better shock absorption performances than other rubbers. Further analysis was extended to determine a shear modulus of SR through the finite element implementation with Blatz-Ko model. As can be seen, relatively higher level of absorption energy results in a decreasing shear modulus.

• 대한기계학회논문집B
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• 제25권6호
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• pp.860-867
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• 2001

In this study, condensation heat transfer experiments were conducted with plate and shell heat exchangers(P&SHE) using R-22. An experimental refrigerant loop has been established to measure the condensation heat transfer coefficient of R-22 in a vertical P&SHE. Two vertical counter flow channels were formed in the P&SHE by three plates of geometry with a corrugated trapezoid shape of a chevron angle of 45°. Downflow of the condensing R-22 in one channel releases heat to the cold upflow of water in the other channel. The effect of the refrigerant mass flux, average heat flux, system pressure and vapor quality of R-22 on the measured data were explored in detail. The results indicate that at a higher vapor quality the condensation heat transfer coefficients are significantly higher. A rise in the refrigerant mass flux causes an increase in the h(sub)r. Also, a rise in the average heat flux causes an increase in the h(sub)r. Finally, at a higher system pressure the h(sub)r is found to be slightly lower. Correlation is also provided for the measured heat transfer coefficients in terms of the Nusselt number.