• Title/Summary/Keyword: 냉동 효과

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Effects of Cryosurgery in Primary Lung Cancer (원발성 폐암에서 냉동수술의 치료 효과)

  • Jung, Won-Jae;Kim, Kwang-Taik;Yi, Eun-Jue;Lee, Sung-Ho;Kang, Moon-Chul;Chung, Jae-Ho;Ham, Soo-Yeoun;Jo, Sung-Bum
    • Journal of Chest Surgery
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    • v.42 no.2
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    • pp.201-205
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    • 2009
  • Background: Cryosurgery has been used to treat primary malignant pulmonary tumors at our institute since November 2004. In this study we analyzed our treatment results and complication rates. Material and Method: A retrospective study using medical charts and imaging data was conducted involving 17 patients with a total of 17 malignant pulmonary tumors who were treated between November 2004 and March 2007. Fourteen patients were males and 3 were females. The median age of the patients was 64 years (range, $54{\sim}77$ years). The average size of the tumors was 48.8mm (range, $36{\sim}111mm$) in diameter. The patients were followed with chest CT scans 7 days, 1 month, 3 months, and 6 months postoperatively. PET scans were obtained between 6 and 9 months postoperatively. The treatment response was analyzed according to the Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Result: Six months after treatment, 6 tumors (35.3%) showed a complete response, 4 (23.5%) had a partial response, 3 (17.6%) had stable disease, and 4 (23.5%) showed disease progression. In tumors <4 cm in diameter, a complete response was reported in 50% of the tumors. A $x^2$-test showed that in tumors <4 cm in diameter, the p-value for results better than a partial response was 0.034. With respect to procedural complications, there was 1 case of blood-tinged sputum which resolved spontaneously within 1 or 2 days, a spontaneously relieved case of subcutaneous emphysema, and 1 patient with a fever. There were no mortalities and the average hospital stay was 6.3 days. Conclusion: The effects of cryosurgery on primary lung cancer is greatest in patients with small tumors. Considering the facts that cryosurgery is minimally invasive, has a low complication rate, and can be performed repetitively, we believe that it may play an important role in the treatment of high risk lung cancer patients.

대체냉매를 적용한 냉동공조기기의 개발 동향

  • 좌성훈
    • Tribology and Lubricants
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    • v.12 no.2
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    • pp.1-7
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    • 1996
  • 최근까지 개발되어진 대체냉매는 매우 다양한데, 실제 적용되고 있고 또한 적용이 고려되고 있는 대체냉매는 주로 기존의 냉매와 열역학적인 특성이 유사하여 기존의 냉동시스템의 구조변경 없이 사용될 수 있는 것들이 주류를 이루고 있으며, 현재 오존층 파괴 효과가 없는 HFC(Hydrofuorocarbon)계통의 냉매가 많이 개발되고 있다. 대체냉매의 적용에는 냉매의 열역학적인 성질 뿐만 아니라 ㅎ 화학적 안정성, 윤활유와의 혼합성, 연소성 등 많은 문제를 고려해야 한다. 본 해설에서는 대체냉매를 적용한 공조시스템의 개발 동향 및 문제점에 관해서 간단히 서술하였으며, 비록 제한적이기는 하나 주로 삼성전자에서 생산되고 있는 냉장고와 에어콘을 모델로 하여 설명하였다.

Condensing heat transfer characteristics of alternative refrigerants in small diameter tubes (세관내 대체냉매의 응축 열전달 특성)

  • 오후규;홍진우
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.28 no.5
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    • pp.396-402
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    • 1999
  • 1980년대부터 본격적으로 제기된 대기 환경 오염 문제로 인해서 CFCs 및 HCFCs계 냉매에 대한 대체 연구가 활발히 진행되었는데, 이와 관련한 열교환기의 고성능화, 콤팩트화 등에 관한 연구도 광범위하게 이루어지고 있다. 이중에서 특기할만 한 것은 종래의 전열관보다 관경이 대단히 적은 세관을 적용하는 경우가 있으며, 그 적응 범위도 점점 더 넓어질 전망이다. 이것은 유효전열 면적의 극대화, 난류효과의 상승, 가공성기 향상, 유연성 등 세관만이 가질 수 있는 여러 가지 전열 성능상의 장점 때문이라 생각한다.

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Influence of Thermal Oscillation on Quality of Frozen Foods Stored in Domestic Refrigerator (가정용 냉장고의 제상 주기와 온도 변화가 저장 식품의 품질에 미치는 영향)

  • Kang, Gil-Jin;Auh, Joong-Hyuck;Kim, Myo-Jeong;Cho, Kwang-Yeun;Choi, Young-Hoon;Jung, Dong-Sun;Kook, Seung-Uk;Park, Kwan-Hwa
    • Korean Journal of Food Science and Technology
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    • v.28 no.4
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    • pp.624-631
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    • 1996
  • Effect of fluctuation range and intervals of defrosting temperature on quality of frozen foods stored in a domestic refrigerator equipped with an automatic defrost system was evaluated. As defrost system was operated, temperatures of domestic refrigerators were elevated from $-18^{\circ}C\;to\;-5^{\circ}C\;and\;-15^{\circ}C$, and fluctuation intervals were l6 hrs and 30 hrs, respectively. Quality deterioration such as protein denaturation, vitamin loss, exudate production and changes in appearance of frozen foods was minimized by reducing temperature oscillation during storage. Considerable effects of thermal oscillation on ice crystal sizes were observed for frozen beef tissue and ice cream. TTI (time temperature indicator) system also proved that the temperature control of defrost system in domestic refrigerator can improve the quality of foods during storage.

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Performance Analysis of New Working Solution for Absorption Refrigeration Machine using Treated Sewage (하수처리수이용 신용액 흡수식 냉동기의 성능해석)

  • 권오경;유선일;윤정인
    • Journal of Energy Engineering
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    • v.7 no.2
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    • pp.231-240
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    • 1998
  • The global environmental problems such as CFC, energy losses in heat recovery system as well as summer peak time power demands, the development of high efficiency absorption refrigeration systems is one of the most promising method in this problems. The absorption refrigeration system to utilize treated sewage is available for environmental protection and energy conservation. Simulation analysis on the double-effect absorption refrigeration cucles with parallel or series flow type has been performed. LiBr+LiI+LiCl+LiNO$_3$ solution was selected as the new working fluid. The main purpose of this study is evaluating the possibilities of effective utilization of treated sewage as a cooling water for the absorber and condenser. The other purpose of the present study is to determine the optimum designs and operating conditions based on the operating constraints and the coefficient of performance in the parallel or series flow type. In this study, we found out the characteristic of new working solution through the cycle simulation and compared LiBr solution to evaluate. The absorption refrigeration machine using the new working fluid was obtained better results COP rise and compactness of system by comparison with LiBr solution.

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Performance Analysis of a Refrigeration System with Parallel Control of Evaporation Pressure (증발압력 병렬제어 냉동시스템의 성능해석)

  • Lee, Jong-Suk
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.8
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    • pp.567-573
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    • 2008
  • The conventional refrigeration system is composed of a compressor, condenser, receiver, expansion valve or capillary tube, and an evaporator. The refrigeration system used in this study has additional expansion valve and evaporator along with an evaporation pressure regulator(EPR) at the exit side of the evaporator. The two evaporators can be operated at different temperatures according to the opening of the EPR. The experimental results obtained using the refrigeration system with parallel control of evaporation pressure are presented and the performance analysis of the refrigeration system with two evaporators is conducted.

Recent R&D Trend in Magnetic Refrigeration at Room Temperature (실온 자기냉동의 최근 연구개발 동향)

  • Lee, Jong-Suk
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.613-618
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    • 2006
  • The 1st International Conference on Magnetic Refrigeration at Room Temperature was held at Montreux, Switzerland during September 27-30, 2005. The conference was the first of its kind to bring together about 140 scientists and engineers interested in magnetic refrigeration in one place. The magnetocaloric effect was discovered in 1881, however, magnetic refrigeration at room temperature was demonstrated to be viable in 1997 Since then, R&D efforts toward magnetic refrigeration have been on the rise around the world, in both areas of systems and materials. The conference reflected the recent R&D trend in magnetic refrigeration at room temperature, which includes the use of permanent magnet instead of superconductor magnet, switch from reciprocating to rotary magnetic refrigeration system, development of magnetic materials based on transition metal elements besides rare earth materials such as gadolinium(Gd).

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