• 제목/요약/키워드: Type-B

검색결과 9,677건 처리시간 0.046초

음이온 치환을 이용한 Li1-xFeO2-yFy-LixMnO2 (Mn/(Mn + Fe) = 0.8, 0≤y≤0.15) 양극 활물질의 합성 및 전기화학적 특성 (Synthesis and Electrochemical Properties of Li1-xFeO2-yFy-LixMnO2 (Mn/(Mn + Fe) = 0.8, 0≤y≤0.15)) Cathode Materials by Anion Substitution)

  • 허정배;박금재;이윤성
    • 전기화학회지
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    • 제10권4호
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    • pp.239-244
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    • 2007
  • 산소자리에 치환된 불소가 $Li_{1-x}FeO_2Li_xMnO_2$ (Mn/(Mn + Fe) = 0.8) 양극 활물질에 미치는 영향을 고찰하기 위해 다양한 양의 불소를 치환시킨 $Li_{1-x}FeO_{2-y}F_y-Li_xMnO_2$ (Mn/(Mn + Fe) = 0.8, $0.05{\le}y{\le}0.15$) 양극 활물질을 고상법을 이용하여 합성하였다. 불소 미치환 시료 및 치환양이 0.05와 0.1의 시료의 경우, $1-1.5\;{\mu}m$ 크기의 막대 형상 분말 형태에 50-100 nm정도의 작은 구형 입자들이 주위에 분포되어 있는 형태이었다. 반면, 불소 치환양이 0.15인 시료의 경우, 그 모양이 구형으로 변화되어지며 입자가 급격하게 성장하였다. 합성된 시료를 이용하여 제작된 셀들의 충 방전 수행 결과, $Li/Li_{1-x}FeO_{1.9}F_{0.1}-Li_xMnO_2$ 셀이 163 mAh/g의 가장 높은 초기용량을 보였으며 50 싸이클 후에도 95%의 높은 가역 특성을 보였다. 특히, 활물질내의 불소 치환양이 증가할수록 초기 방전용량도 같이 증가하였으나, 불소이온의 치환양이 일정량을 (y>0.1) 넘는 경우에는 산소 자리에 불소이온이 완전하게 치환되지 못하고 불순물로 존재함으로써 전지의 가역특성을 현저하게 저하시키는 요인으로 작용함을 확인하였다.

리튬 이차전지 음극용 Cu3Si의 고온에서의 전기화학적 특성 (Electrochemical Characteristics of Cu3Si as Negative Electrode for Lithium Secondary Batteries at Elevated Temperatures)

  • 권지윤;류지헌;김준호;채오병;오승모
    • 전기화학회지
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    • 제13권2호
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    • pp.116-122
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    • 2010
  • DC magnetron 스퍼터링을 이용해 구리(Cu) 호일 위에 실리콘(Si)을 증착한 후 $800^{\circ}C$에서 열처리하여 $Cu_3Si$를 얻고, 이의 리튬 이차전지용 음극으로서 특성을 조사하였다. $Cu_3Si$는 Si 성분을 포함하고 있으나 상온에서 리튬과 반응하지 않았다. 선형 주사 열-전류(linear sweep thermammetry, LSTA) 실험과 고온 충방전 실험을 통하여, 상온에서 비활성인 $Cu_3Si$$85^{\circ}C$ 이상에서는 활성화되어 Si 성분이 전환(conversion)반응에 의해 리튬과 반응함을 확인하였다. $Cu_3Si$에서 분리된 Si는 $120^{\circ}C$에서 Li-Si 합금 중에서 리튬의 함량이 가장 많은 $Li_{21}Si_5$ 상까지 리튬과 반응함을 유사 평형 조건(quasi-equilibrium)의 실험으로부터 알 수 있었다. 그러나 정전류 조건($100\;mA\;{g_{Si}}^{-1}$)에서는 리튬 합금반응이 $Li_{21}Si_5$까지 진행되지 못하였다. 또한 $120^{\circ}C$에서 전환반응에 의해 생성된 Li-Si 합금과 금속 상태의 Cu는 충전과정에서 다시 $Cu_3Si$로 돌아감, 즉 $Cu_3Si$와 리튬은 가역적으로 반응함을 확인하였다. $120^{\circ}C$에서 $Cu_3Si$ 전극은 비정질 실리콘 전극보다 더 우수한 사이클 특성을 보여 주었다. 이는 비활성인 구리가 실리콘의 부피변화를 완충하여 집전체에서 탈리되는 현상을 완화하고 결과적으로 전극이 퇴화하는 것을 억제하기 때문인 것으로 설명할 수 있다. 실제로 비정질 실리콘 전극은 충방전 후에 실리콘 층의 균열과 탈리가 관찰되었으나, $Cu_3Si$ 전극에서는 이러한 현상이 관찰되지 않았다.

당뇨유도 백서 경골에 티타늄 임플란트 매식 시 지방조직 유래 줄기세포 주입 후 저출력 초음파 적용이 골치유에 미치는 영향 (Effect on bone healing by the application of low intensity pulsed ultrasound after injection of adipose tissue-derived stem cells at the implantation of titanium implant in the tibia of diabetes-induced rat)

  • 정태영;박상준;황대석;김용덕;이수운;김욱규
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제37권4호
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    • pp.301-311
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    • 2011
  • Introduction: This study examined the effect of the application of low intensity pulsed ultrasound on bone healing after an injection of adipose tissue-derived stem cells (ADSCs) during the implantation of a titanium implant in the tibia of diabetes-induced rats. Materials and Methods: Twelve Sprague-Dawely rats were used. After inducing diabetes, the ADSCs were injected into the hole for the implant. Customized screw type implants, 2.0 mm in diameter and 3.5 mm in length, were implanted in both the tibia of the diabetes-induced rats. After implantation, LIPUS was applied with parameters of 3 MHz, 40 mW/$cm^2$, and 10 minutes for 7 days to the left tibiae (experimental group) of the diabetesinduced rats. The right tibiae in each rat were used in the control group. At 1, 2 and 4 week rats were sacrificed, and the bone tissues of both tibia were harvested. The bone tissues of the three rats in each week were used for bone-to-implant contact (BIC) and bone area (BA) analyses and the bone tissues of one rat were used to make sagittal serial sections. Results: In histomorphometric analyses, the BIC in the experimental and control group were respectively, $39.00{\pm}18.17%$ and $42.87{\pm}9.27%$ at 1 week, $43.74{\pm}6.83%$ and $32.27{\pm}6.00%$ at 2 weeks, and $32.62{\pm}11.02%$ and $47.10{\pm}9.77%$ at 4 weeks. The BA in experimental and control group were respectively, $37.28{\pm}3.68%$ and $31.90{\pm}2.84%$ at 1 week, $20.62{\pm}2.47%$ and $15.64{\pm}2.69%$ at 2 weeks, and $11.37{\pm}4.54%$ and $17.69{\pm}8.77%$ at 4 weeks. In immunohistochemistry analyses, Osteoprotegerin expression was strong at 1 and 2 weeks in the experimental group than the control group. Receptor activator of nuclear factor kB ligand expression showed similar staining at each week in the experimental and control group. Conclusion: These results suggest that the application of low intensity pulsed ultrasound after an injection of adipose tissue-derived stem cells during the implantation of titanium implants in the tibia of diabetes-induced rats provided some positive effect on bone regeneration at the early stage after implantation. On the other hand, this method is unable to increase the level of osseointegration and bone regeneration of the implant in an uncontrolled diabetic patient.

그린키위 및 골드키위를 이용한 프렌치 드레싱 제조의 혼합비율 최적화의 연구 (A Study on the Optimization of Green Kiwi and Gold Kiwi Puree Mixing Ratio for the Best French Kiwi Dressing)

  • 조인숙;진현희;이승주
    • 한국조리학회지
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    • 제21권4호
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    • pp.16-28
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    • 2015
  • 이 연구는 새로운 드레싱의 개발 목적의 일환으로 그린키위 및 골드키위의 첨가량을 달리하여 적합한 가공 및 조리 방법을 모색하고, 항산화성을 규명하여, 이를 드레싱에 활용하였을 때 현대인의 입맛에 맞는 향상된 키위드레싱의 제조에 적합한 최적 조건을 제시하고자 하였다. 예비실험에서 가장 선호도가 좋았던 그린키위 150, 골드키위 150, 그린키위 50: 골드키위 100, 그린키위 100: 골드키위 50, 그린키위 75: 골드키위 75로 제조하여 키위 퓨레 150 g을 기준으로 드레싱을 제조한 후, 품질특성으로 기계적 특성과 관능검사를 실시하였다. 키위드레싱의 점도는 GD2 시료로 단일 키위로 제조한 것보다 두 가지 키위를 섞은 과일이 더 높은 점도를 나타내는 결과를 보였다. 당도 측정의 경우, 골드키위의 비율을 많이 첨가할수록 당도가 높게 나타났으며, 염도는 그린키위로만 제조한 GR1 드레싱이 2.16%로 가장 높은 염도를 보였다(p<0.05). pH는 2.34~2.47의 범위를 보였으며, 총 산도의 경우 그린키위로만 제조한 드레싱이 1.86%로 가장 높은 값을 보였다. 그린키위 및 골드키위로 제조한 드레싱의 총페놀 함량은 골드키위의 함량이 늘어남에 따라 유의적으로 증가하였고, DPPH의 라디칼 소거활성은 폴리페놀 함량과 같이 모두 골드키위 함량의 증가함에 비례하는 결과를 보였다. 색도에서는 골드키위 함량이 높을수록 대체적으로 증가하였고, a값(-2.75)과 b값(17.50) 모두 GD1이 가장 높은 값을 나타냈다(p<0.05). 관능 검사에서 전반적인 기호도(overall acceptability)는 골드키위와 그린키위를 1:1로 믹싱하여 제조한 드레싱이 가장 높은 것으로 나타났다. 위의 결과로부터 골드키위와 그린키위의 드레싱 제조시 키위 퓨레를 1:1 비율로 믹스하여 식용유 130 g, 양파 50 g, 설탕 40 g, 식초 30 g, 레몬쥬스 30 g, 소금 5 g을 첨가한다면 드레싱의 기호도와 품질을 향상시킬 수 있을 것으로 기대된다.

수도(水稻)의 역학적(力學的) 및 리올러지 특성(特性)에 관(關)한 연구(硏究) (Mechanical and Rheological Properties of Rice Plant)

  • 허윤근;차균도
    • 농업과학연구
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    • 제14권1호
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    • pp.98-133
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    • 1987
  • The mechanical and rheological properties of agricultural materials are important for engineering design and analysis of their mechanical harvesting, handling, transporting and processing systems. Agricultural materials, which composed of structural members and fluids do not react in a purely elastic manner, and their response when subjected to stress and strain is a combination of elastic and viscous behavior so called viscoelastic behavior. Many researchers have conducted studies on the mechanical and rheological properties of the various agricultural products, but a few researcher has studied those properties of rice plant, and also those data are available only for foreign varieties of rice plant. This study are conducted to experimentally determine the mechanical and the rheological properties such as axial compressive strength, tensile strength, bending and shear strength, stress relaxation and creep behavior of rice stems, and grain detachment strength. The rheological models for the rice stem were developed from the test data. The shearing characteristics were examined at some different levels of portion, cross-sectional area, moisture content of rice stem and shearing angle. The results obtained from this study were summarized as follows 1. The mechanical properties of the stems of the J aponica types were greater than those of the Indica ${\times}$ Japonica hybrid in compression, tension, bendingand shearing. 2. The mean value of the compressive force was 80.5 N in the Japonica types and 55.5 N in the Indica ${\times}$ Japonica hybrid which was about 70 percent to that of the Japonica types, and then the value increased progressively at the lower portion of the stems generally. 3. The average tensile force was about 226.6 N in the Japonica types and 123.6 N in the Indica ${\times}$ Japonica hybrid which was about 55 percent to that of the Japonica types. 4. The bending moment was $0.19N{\cdot}m$ in the Japonica types and $0.13N{\cdot}m$ in the Indica ${\times}$ Japonica hybrid which was 68 percent to that of the Japonica types and the bending strength was 7.7 MPa in the Japonica types and 6.5 MPa in the Indica ${\times}$ Japonica hybrid respectively. 5. The shearing force was 141.1 N in Jinju, the Japonica type and 101.4 N in Taebaeg, the Indica ${\times}$ Japonica hybrid which was 72 percent to that of Jinju, and the shearing strength of Taebaeg was 63 percent to that of Jinju. 6. The shearing force and the shearing energy along the stem portion in Jinju increased progressively together at the lower portions, meanwhile in Taebaeg the shearing force showed the maximum value at the intermediate portion and the shearing energy was the greatest at the portion of 21 cm from the ground level, and also the shearing strength and the shearing energy per unit cross-sectional area of the stem were the greater values at the intermediate portion than at any other portions. 7. The shearing force and the shearing energy increased with increase of the cross-sectional area of the rice stem and with decrease of the shearing angie from $90^{\circ}$ to $50^{\circ}$. 8. The shearing forces showed the minimum values of 110 N at Jinju and of 60 N at Taebaeg, the shearing energy at the moisture content decreased about 15 percent point from initial moisture content showed value of 50 mJ in Jinju and of 30 mJ in Taebaeg, respectively. 9. The stress relaxation behavior could be described by the generalized Maxwell model and also the compression creep behavior by Burger's model, respectively in the rice stem. 10. With increase of loading rate, the stress relaxation intensity increased, meanwhile the relaxation time and residual stress decreased. 11. In the compression creep test, the logarithmic creep occured at the stress less than 2.0 MPa and the steady-state creep at the stress larger than 2.0 MPa. 12. The stress level had not a significant effect on the relaxation time, while the relaxation intensity and residual stress increased with increase of the stress level. 13. In the compression creep test of the rice stem, the instantaneous elastic modulus of Burger's model showed the range of 60 to 80 MPa and the viscosities of the free dashpot were very large numerical value which was well explained that the rice stem was viscoelastic material. 14. The tensile detachment forces were about 1.7 to 2.3 N in the Japonica types while about 1.0 to 1.3 N in Indica ${\times}$ Japonica hybrid corresponding to 58 percent of Japonica types, and the bending detachment forces were about 0.6 to 1.1 N corresponding to 30 to 50 percent of the tensile detachment forces, and the bending detachment of the Indica ${\times}$ Japonica hybrid was 0.1 to 0.3 N which was 7 to 21 percent of Japonica types. 15. The detachment force of the lower portion was little bigger than that of the upper portion in a penicle and was not significantly affected by the harvesting period from September 28 to October 20. 16. The tensile and bending detachment forces decreased with decrease of the moisture content from 23 to 13 percent (w.b.) by the natural drying, and the decreasing rate of detachment forces along the moisture content was the greater in the bending detachment force than the tensile detachment force.

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비정신과 간호원의 정신질환 및 정신질환자에 대한 태도 조사 연구 (A Study of the Attitudes of Nonpsychiatric Registered Nurses towards Mental illness and Mental Patients)

  • 박예숙
    • 대한간호학회지
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    • 제3권2호
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    • pp.31-43
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    • 1973
  • The trend in modern nursing is toward the performance of comprehensive nursing care. Psychiatric nursing emphasizes education which enables the nurse to understand the underlying difficulties being expressed through a wide range of emotions and through practice to be more adept in her selection of a manner of approach which best meets the needs of a given situation. Presently, in Korea, there is nothing in the literature regarding evaluation of the effect of psychiatric nursing education on the attitudes of nurses towards mental illness and mentally ill patients. This stud!1 was attempted in order to understand 1) some of the problems in psychiatric nursing education 2) some of tile factors which affect the attitudes of nurses towards mental illness and mental patients. A questionnaire, a Korean translation of the "Opinions about Mental illness Scale" by Cohen and Stranding, 1962, was administered to 188 nonpsychiatric registered nurses employed in Yonsei University Hospital (Y. Hospital) and Seoul National University Hospital (S. Hospital) located in the city of Seoul. All of the nurses were directly involved with adult patient care. They graduated from various nursing schools. The data was collected during the period of October 2 to October 16,1972. The age, educational background , marital status, type of previous psychiatric experience, experience as a graduate nurse and close personal relationship with someone who was a psychiatric patient were compared with the O.M.I. scores. The mean and standard errors for each of the comparison groups were computed and tile relationships calculated by a t-test. The results of the study are summarized as follow: 1. There is no significant difference between the age of the nurses and their attitudes toward mental illness and mental patients. 2. There is no significant difference between the. educational backgrounds of the nurses and their attitudes toward mental illness and mental patients. 3. There is a significant difference in the nurses ′student psychiatric nursing experience and their attitudes towards mental illness and mental patients for the nurses in 5. Hospital only. The nurses who had 3-4 week of student psychiatric nursing experience had a significantly higher mean score for Benevolence (factor B) than nurses whose student psychiatric experience had been less than 1 Ivcek (P<0.05). The nurses who had 1-2 weeks, 3-4 weeks and more than 4 weeks of student psychiatric nursing experience had significantly higher mean scores for Interpersonal Ethology (factor E) than nurses whose student psychiatric had been less than 1 week (p<0.05), 4. There is a significant difference in the nurses′student psychiatric nursing experience by types of institution and their attitudes towards mental illness and mental patients for S. Hospital nurses only. The nurses who had their student psychiatric nursing experience in the government psychiatric hospitals recorded significantly higher mean score for Authoritarianism (factor A) than nurses who had their. experience in private psychiatric hospitals (p<0.05). 5. There is no significant difference in the nurses′psychiatric nursing experience as a graduate nurse and their attitudes toward mental illness and mental patients. 6. There is no significant difference in the nature and variety of the nurses′experience as a graduate nurse and their attitude toward mental illness and mental patients. 7. There is no significant difference in the presence or absence of a close personal relationship with a mentally ill person and the nurses′attitude toward mental illness and mental patients. 8. There is no significant difference in the nurses′ marital status and their attitude toward mental illness and mental patients. 9. There is no significant difference between the nurses who were employed ill S. and Y. hospitals and their attitudes towards mental illness and mental patients. Major suggestion for further study was to have more larger and wider scale research for establishing of the reliability and validity of the Korean translation of the O.H.I. Scale.

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일개 도농복합시 영유아 예방접종 수첩의 정확도 평가 (Evaluation on the Accuracy of Vaccination Card for National Immunization Program in a 2005 Population-Based Survey in Nonsan, Korea)

  • 이무식;김지희;김광환;홍지영;이진용;김건엽
    • 농촌의학ㆍ지역보건
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    • 제36권2호
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    • pp.113-119
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    • 2011
  • 목적 : 이 연구는 국가예방접종률 산출 및 조사방법론 개발을 위한 기반을 조성하기 위하여 예방접종률 파악을 위한 자료원 중 영유아 예방접종 수첩기록의 정확도를 평가하기 위하여 수행되었다. 대상 및 방법 : 연구대상은 2005년 1월 31일을 기준으로 충청남도 논산시에 주민등록상 거주하는 생후 12-35개월 영유아 전체로 하였다. 연구대상자가 거주하는 가구를 2005년 2-4월까지 방문하여 보호자의 동의를 얻어 예방접종 수첩기록을 조사하였다. 예방접종 수첩기록의 정확도를 평가하기 위하여 2005년 5-7월까지 예방접종을 시행한 의료기관 및 보건소의 접종관련 기록을 확보하여 예방접종 접종 여부 및 접종 일자의 기록 일치 여부를 확인하였다. 비교 대상 예방접종은 결핵(BCG), B형간염, 디프테리아/파상풍/백일해 (DTaP), 홍역/유행성이하선염/풍진(MMR), 폴리오, 일본뇌염, 수두, 인플루엔자, B형 헤모필루스 인플루엔자 뇌수막염(Hib), A형간염, 폐구균으로 총 11종을 대상으로 하였다. 결과 : 예방접종 수첩의 예방접종 여부 및 접종 일시 기록의 정확도는 BCG는 69.5% 및 80.1%였으며, B형 간염은 1차 41.3% 및 89.7%, 2차 76.6% 및 82.1%, 3차 79.7% 및 79.0%였으며, DTaP는 1차 79.9% 및 87.5%, 2차 80.8% 및 87.3%, 3차 82.5% 및 85.1%, 4차 79.9% 및 83.5%였으며, 폴리오는 1차 79.5% 및 88.1%, 2차 79.8% 및 86.2%, 3차 82.1% 및 84.8%였으며, MMR은 83.2% 및 84.0%였으며, 일본뇌염 1차는 80.7% 및 83.1%였으며, 수두는 74.9% 및 83.7%였으며, 인플루엔자는 74.1% 및 55.3%였으며, Hib 1차는 72.7% 및 90.7%였으며, A형 간염 1차는 79.5% 및 88.4%였으며, 폐렴구균 1차는 73.2% 및 90.3%로 나타났다. 결론 : 여러 가지 연구의 제한점에도 불구하고, 예방접종 수첩의 상당한 수준의 신뢰도를 확인하였으나 수첩의 예방접종력 정확도 및 타당도에 대한 추가 연구가 필요할 것으로 판단된다.

수도 직파재배의 경제성분석 -대단위 대호간척농지를 중심으로- (Economic Analysis of Rice Production by Seed Broadcasting -In the Case of Daeho Large Scale Tidal and Development Area-)

  • 임재환;유영희
    • 농업과학연구
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    • 제23권2호
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    • pp.301-322
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    • 1996
  • This study is first aimed at identifying the possibility of labour saving and production cost decreasing in rice production with respect to seed broad casting technology. Comparison of labour inputs and production costs of rice in-between USA and Korea and recommendation of policy guidelines for the continous rice cultivation are the second objective of this study. Under the WTO system, rice enterprice is the most vulnerable crop in the sense of labour productivity and price competitiveness in the international market. How to adapt labour saving technology and how to decrease production costs are the most imminent problems to be solved in rice production. To achieve the objectives, survey on nine rice enterprice farms were made in Daeho tidal farmland with respect to the size of farm, labour inputs, productivity, farm mechanization and farm land base development. The existing data on labour saving technology by seed broadcasting which had surveyed by Rural Development Administration were collected to compare the surveyed data from Daeho tidal farm land The study results and policy recommendation are summarized as follows; 1. Labour requirements per 10a for rice enterprise farms with seed broadcasting and with transplanting were estimated 11.4 and 18.5hours respectively. 'This above labour inputs were equivalent to 1/3-1/5 of the national average labour inputs of 53.6 hours which were included transplanting and harvesting by machinery. Considering the labour requirement of 1.7 hours per 10a for the USA rice production, Korea rice culture has possibility to decrease labour demand upto USA level of labour inputs. 2. Production cost of rice in Korea were estimated US$4,181 per ha which were higher than that of USA by 3.00 times and production costs per ton were shown as US$313 for USA rice and US$1,018 for Korean rice. 3. Land productivity of rice per 10a in America was reached to 4,325kg and the counterpart of Korea was about 4,181kg in recent year. In the sense of land productivity, both yields of rice were comparable. 4. The price of japonica type rice similar to Korean traditional rice in international market in 1994 was f.o.b US$466 per ton which was equivalent to import parity price of US$830 per ton in domestic market. The price of rice purchased by Korean G't and received by farmers were amounted to US$ 2,013 and US$ 1,663 respectively in the same year. Domestic prices mentioned above were higher than the import parity price as US$830 by 2.0-2.4 times. 5. American rice production competitive to Korean rice was equivalent to 17,012 thousand tons, 1.28% of the world production of rice in 1991 and consumption of rice in America was amounted to 2,633 thousand tons. Exportable quantity of USA rice were estimated as 4,379 thousand tons of which 52.3%, 2,300 thousand tons, were exported indeed in the same year. 6. The quantity of Korean rice produced in 1991 was estimated 1.00% of the world production. The world amount of rice exported in 1991 was reached to 2.45% of the world production of which 34.2% was occupied by USA The remaining quantities of world exported rice were dominated by Tiland, Pakistan and Vietnam where produced indica variety. 7. Under the given technology, labour inputs per 10a for rice production could be possible to save by 70% of the national average labour requirement of 53.6 hours through implmenting complete farm mechanization with land consolidation and on-farm development and improvement of fanning practices like seedbroad casting txchnology etc. On the other hand, prduction costs of rice could be decreased by 10% rather than 49% as target indicated in the Rural Development Counter Measures of Korean Government in 1994 owing to increasing farm mechanization cost and interest on land service with high price. Accordingly production cost of rice per kg could be decreased only by 10% of the 1994 production cost. 8. Rice policy of Korean government in the future should take into account the labour saving technology to solve labour shortage in rural area and to enhance off-farm incomes by creating job opportunities in agro-industrial zones and special production area. On account of the staple food and main energy source for people's health, rice production even encountered vulnerable economic settings should be continued without price distortion policies and discouraging farmer's intention to cultivate rice by importing institutionally the direct income subsidy system.

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비소세포 폐암에서 EGFR의 발현률과 생존률에 미치는 영향 (Expression of EGFR in Non-small Cell Lung Cancer and its Effects on Survival)

  • 김학렬;정은택
    • Tuberculosis and Respiratory Diseases
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    • 제44권6호
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    • pp.1285-1295
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    • 1997
  • 연구배경 : 종양형성다단계 과정중의 하나인 EGFR(epidermal growth factor receptor)은 170KDa의 당단백질로서 세포막의 안팎에 걸친 수용체로서 EGF, TGF alph 의 자극에 의해서 신호전달체계의 시작을 담당한다. EGFR은 정상세포에도 존재가능하나 종양에서는 발현이 증가되어 있으며, EGFR의 발현이 높을수록 종양의 예후가 불량하리라 예측된다. 이에 저자들은 비소세포 폐암에서 EGFR의 발현을 확인하고 EGFR의 임상적 의의 특히 생존률과의 관계를 검색 하였다. 방 법 : 원발성 비소세포 폐암으로 확진받고, 외과적 절제술후 paraffin에 보관된 57례의 병리조직에서 면역 조직화학법으로 EGFR의 발현을 확인하고, EGFR과 암세포형, TNM 병기, 세포분화도, 유식세포 분석법에 의한 S 및 $G_1$ 주기비율 그리고 생존 기간과의 관계를 분석하였다. 결 과 : 1) 57례중 남녀비는 43 : 14였고, 중간 연령은 62세였다. EGFR과 생존기간과의 경향을 파악하기 위해, 종양세포중 EGFR 양성 세포가 20% 이상인 경우만을 발현군으로 하였을 때 56%에서 발현되었다. 2) EGFR의 발현은 병리조직형에 따른 차이는 없었고, TNM병기 그리고 세포의 분화도에 따른 차이도 없었다. 3) EGFR 발현군과 비발현군에서의 S-주기비율은 22.3(${\pm}10.5$)%, 18.0(${\pm}10.9$)% 였고, $G_1$-주기비율은 68.4(${\pm}11.6$)%, 71.1(${\pm}12.8$)%로서 모두 양군간의 유의한 차이는 없었다. 4) EGFR 발현군과 비발현군에서의 1년 생존률은 66%, 96%, 2년 생존률은 53%, 84%, 3년 생존률은 38%, 66%였고 중간 생존기간은 26개월, 53개월로서 유의한 차이가 있었다. 결 론 : 비소세포 폐암에서 EGFR은 56%에서 발현되었으며, 조직병리형, TNM 병기, 세포분화도에 따른 발현의 차이는 없었다. 발현군과 비발현군에서의 S 및 $G_1$ 주기비율은 차이가 없었다. EGFR 발현군과 비발현군의 2년 생존률은 53%, 84%였으며, 중간 생존기간은 26개월, 53개월이었다 (p<0.05). 즉 결과적으로 EGFR 발현이 높을수록 생존기간은 불량하여 예후추정인자로서의 이용이 가능하리라 판단된다.

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설비공학 분야의 최근 연구 동향: 2011년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2011)

  • 한화택;이대영;김서영;최종민;백용규;김수민
    • 설비공학논문집
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    • 제24권6호
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    • pp.521-537
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    • 2012
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2011. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of fluid machinery and fluid flow, thermodynamic cycle, and new and renewable energy. Various topics were presented in the field of fluid machinery and fluid flow. Research issues mainly focused on the rankine cycle in the field of thermodynamic cycle. In the new and renewable energy area, researches were presented on geothermal energy, fuel cell, biogas, reformer, solar water heating system, and metane hydration. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer, nanofluids and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer above liquid helium surface in a cryostat, methane hydrate formation, heat and mass transfer in a liquid desiccant dehumidifier, thermoelectric air-cooling system, heat transfer in multiple slot impinging jet, and heat transfer enhancement by protrusion-in-dimples. In the area of pool boiling and condensing heat transfer, researches on pool boiling of water in low-fin and turbo-B surfaces, pool boiling of R245a, convective boiling two-phase flow in trapezoidal microchannels, condensing of FC-72 on pin-finned surfaces, and natural circulation vertical evaporator were actively performed. In the area of nanofluids, thermal characteristics of heat pipes using water-based MWCNT nanofluids and the thermal conductivity and viscosity were measured. In the area of industrial heat exchangers, researches on fin-tube heat exchangers for waste gas heat recovery and Chevron type plate heat exchanger were implemented. (3) Refrigeration systems with alternative refrigerants such as $CO_2$, hydrocarbons, and mixed refrigerants were studied. Heating performance improvement of heat pump systems were tried applying supplementary components such as a refrigerant heater or a solar collector. The effects of frost growth were studied on the operation characteristic of refrigeration systems and the energy performance of various defrost methods were evaluated. The current situation of the domestic cold storage facilities was analyzed and the future demand was predicted. (4) In building mechanical system fields, a variety of studies were conducted to achieve effective consumption of heat and maximize efficiency of heat in buildings. Various researches were performed to maximize performance of mechanical devices and optimize the operation of HVAC systems. (5) In the fields of architectural environment and energy, diverse purposes of studies were conducted such as indoor environment, building energy, and renewable energy. In particular, renewable energy and building energy-related researches have mainly been studied as reflecting the global interests. In addition, various researches have been performed for reducing cooling load in a building using spot exhaust air, natural ventilation and energy efficiency systems.