• 한국환경보건학회지
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• 제7권1호
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• pp.9-20
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• 1981

This study was performed to determine the correlationship between temperature and overall removals of BOD, SS and to demonstrate the effect of temperature on treatment performance. These data for a period from February 1, 1977 to January 31, 1980 were obtained from the Cheong-Gye Cheon Sewage Treatment plant. The results of correlation and stepwise multiple regression analysis were as follows. 1) Secondary effluent BOD and SS showed negative correlationship with water temperature, with correlation coefficient of -0.1710, and -0.1654 respectively. 2) Correlation coefficient of BOD, SS removal rate and water temperature were 0.1823 and 0.0429 respectively. 3) Regresion equation for estimate of BOD removal rate was as follows $\widehat{Y}_1$ (BOD removal rate)=63.9994+0.5442X(water temperature). And BOD removal rate showed non significant change according to the water temperature. 4) Regression equation for estimate of SS removal rate was as follows $\widehat{Y}_2$ (SS removal rate)=61.6881+0.1514X(Water temperature). And SS removal rate showed non significant change according to the water temperature. 5) According to the Stepwise Multiple Regression analysis, water temperature ranked second order in the BOD removal rate estimation and the equation was as follows $\widehat{Y}_1$ (BOD removal rate)=69.7398+0.2665 $X_1$ (Primary effluent BOD)+0.3562 $X_2$ (Water temperature)-0.0122 $X_3(Flow)+4413.271X_4$ (Organic Loading).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.66-69
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• 2001

Effect of $N_2$ flow rate on properties of GaN thin films grown by plasma-enhanced molecular beam epitaxy(PEMBE) was discussed to optimize the quality of thin films. It was found that at low $N_2$ flow rate indicating high III/V flux ratio, the growth rate of GaN thin films was controlled by $N_2$ flux, and at high $N_2$ flow rate the growth rate was not controlled by $N_2$ flux any longer. It was also found that III/V flux ratio affected film quality. The film grown at higher $N_2$ flow rate showed low background carrier concentration, higher carrier mobility, and narrow FWHM in band-edge emission of low temperature PL. It is thought that the film in more Ga flux region was grown by 2-dimensional layer-by-layer growth mode, and the film in more nitrogen region was grown by 3-D island growth mode. All samples exhibited a good crystallinity.

• 한국수정란이식학회지
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• 제25권1호
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• pp.21-27
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• 2010

The increase in the total number of cows on farms, which breed Korean Native Cattle (KNC), is associated with many problems. In particular, the services per conception and calving interval have increased. In this study, we examined the effect of dietary supplementation with vitamin and mineral complex on the estrus rate, pregnancy rate, gestation length, and birth weight of KNC calves. Multiparous or primiparous KNC were divided into 3 groups with 40 heads per group. Experimental group 1 was administered a consisting of 35,000 IU vitamin A, 100 IU vitamin E, 200 mg $\beta$-carotene, 200 mg Zn methionine, and 1.5 mg Se. Experimental group 2 was administered a vitamin complex (100 g/day) consisting of 100 IU vitamin E and 200 mg $\beta$-carotene. In the case of multiparous KNC, the estrus detection rate in the control group was 90.0% and those in the experimental groups were 75.0% to 95.0%. However, the first-service pregnancy rate after parturition in the control group was 41.2%, which was significantly lower than that in the experimental groups (71.0% to 76.7%; p<0.05). The average duration of pregnancy in the group supplemented with the vitamin complex was days, which was similar to that in the case of the control group. The birth weight of calves from cows fed with vitamin complex was 25.3 to 27.0 kg, which was similar to that in the case of the control group (25.2 to 26.0 kg). In the case of primiparous KNC, no differences in the estrus rate, pregnancy rate, gestation length, or the birth weight of calves were noted between the groups. Thus, dietary supplementation vitamin and mineral complex have no effect on the reproductive efficiency in primiparous cows, but the pregnancy rate was observed to have increased in multiparous KNC with these supplements.

• 대한방사선기술학회지:방사선기술과학
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• 제37권1호
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• pp.21-28
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• 2014

배양된 췌장베타세포와 신경세포를 10% FBS (fetal bovine serum), 11.1 mM glucose의 normal 조건과 1% FBS, 30 mM glucose의 hyperglycemia 조건으로 배양하고, 저 LET X-선을 0.5 Gy/hr의 선량률로 총 선량이 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 Gy가 되도록 저 LET 방사선을 조사한 후 MTT assay로 생존율을 측정하고 비교하였다. 분화된 췌장베타세포에 방사선을 조사하지 않았을 때는 normal 조건에 비해 hyperglycemia 조건의 생존율이 경미한 감소를 보였다. 그러나 X선의 총 선량이 점차 누적됨에 따라 normal 조건에서 생존율이 조금씩 감소하는 것에 비해 hyperglycemia 조건에서는 급격히 감소하여 시너지 효과를 나타냈다. 미분화된 신경세포에서는 방사선을 조사하지 않은 때도 normal 조건에 비해 hyperglycemia 조건의 생존율이 뚜렷하게 감소하였다. X선의 총 선량이 점차 누적됨에 따라 normal 과 hyperglycemia 조건 모두에서 비교적 급격한 세포사멸이 나타났지만 그 생존율의 감소비율이 거의 평행하게 진행되어 시너지 효과를 보이지 않았다.

• 한국주조공학회지
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• 제17권4호
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• pp.347-355
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• 1997

It is well known that the coarse primary Si in hypereutectic Al-Si alloys deteriorate castability, machinability, and mechanical properties. So, many treatment has been tried to refine the primary Si increasing cooling rate and adding refinement agent. Therefore. the purpose of our work was the observation of the effect on the refinement of primary Si and the analysis of the trend to apply to the casting process by changing the amount of P addition and the cooling rate while fixing the temperature at $750^{\circ}C$ of P addition and the type of AlCuP. In the condition of amount of P addition was fixed, primary Si was finer as cooling rate increased but in case of cooling rate was fixed, the effect of refinement was resisted as incersed the amount of P addition. At a relatively slow cooling rate of $22^{\circ}C/sec$, refinement was governed by the amount of P addition rather than cooling rate. At elevated cooling rate of $51^{\circ}C/sec$ and $99^{\circ}C/sec$, the undercooling due to faster cooling rate promoted nucleation of primary Si rather than P addition more significantly.

• 생명과학회지
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• 제20권8호
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• pp.1261-1267
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• 2010

본 연구는 체지방을 감소시키는데 효과적이라는 diacylglycerol (DG) 섭취와 유산소운동이 체구성비의 변화 및 혈중지질 개선에 미치는 영향을 규명하고 안정 시 대사량 변화를 관찰함으로써 임상적 및 대사적 측면에서 비만 개선 효과를 규명하는데 그 목적이 있었다. 본 연구의 대상은 의학적으로 다른 질병을 동반하지 않은 비만 남자 대학생으로서 연구의 의의를 충분히 이해하고 자발적으로 참여 의사를 밝힌 사람으로 선정하였으며, 체지방 측정 후 25%미만인 자와 흡연자는 대상에서 제외하였다. 모든 피험자들은 기본검사와 사전검사가 끝난 후 세가지(D, E, DE) 집단에 6명씩 무선 배정하였다. 첫 번째 실험군(D)은 diacylglycerol 섭취 조건으로 12주 동안 diacylglycerol을 섭취하였고, 두 번째 실험군(E)은 12주 동안 러닝 트레이닝을 실시하였다. 마지막 세번째 실험군(DE)은 12주 동안 diacylglycerol 섭취와 유산소 트레이닝을 실시하였으며, 본 연구결과 모든 그룹에서 12주 동안의 그룹별 처치가 진행됨에 따라 체지방이 감소하는 경향을 보였다. 안정 시 대사량은 D그룹을 제외하고 모든 그룹에서 증가하는 경향을 보였으며 운동과 다이아실글리세롤 섭취에 따라 콜레스테롤의 감소가 일어났다. 추후 카테콜라민, CAMP, HSL, Insulin 등과 같은 지방대사와 관련된 항목들에 대한 추가적인 분석이 이루어짐으로써, DG섭취와 트레이닝의 비만개선효과를 보다 신뢰성 높게 예측할 수 있으리라 본다.

• 한국항만경제학회지
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• 제32권4호
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• pp.89-107
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• 2016

북항터미널과 신항터미널간의 심각한 출혈경쟁이 부산항의 경쟁력을 약화시키는 것은 부산항 컨테이너 하역시장의 중대한 문제점이다. 이러한 심각한 출혈경쟁을 방지하기 위해, 부산항만공사는 작년에 하역요율 인가제를 실시하였다. 그러나, 부산항 컨테이너 터미널 운영사들이 이를 수용하지 않으면 그 효과는 미흡할 것이다. 따라서, 본 연구의 목적은 부산항 컨테이너 하역시장에서 이러한 하역요율 인가제 실시의 효과를 검정하는 것이다. 이러한 연구목적을 달성하기 위해, 현재의 부산항 운영현황을 분석하고 선행연구를 검토하여 하역시장 안정화 요인을 추출하고 이 요인들과 인가제간의 조절효과를 검증하였다. 연구결과에 의하면, 첫째로, 세 가지 하역시장 안정화 요인(시장구조, 시장행동 그리고 부산항만공사 요인)은 안정화 효과와 매우 강한 정의 관계를 보여주고 있지만 운영사 요인은 그렇지 못한 것으로 나타나고 있다. 특히, 하역요율 덤핑규제와 같은 시장행동요인은 하역시장 안정화에 기여하는 것으로 나타나고 있다. 둘째로, 인가제 자체뿐만 아니라 하역시장 안정화 요인과 인가제간의 조절효과(상호작용효과)도 하역시장 안정화에 강한 영향을 미치는 것으로 나타나고 있다. 이러한 연구결과는 인가제 시행이 부산항 컨테이너 하역시장에 매우 중요한 정책임을 시사하는 것으로 볼 수 있다. 하역시장을 안정화하는 것이 부산항의 이미지 개선과 글로벌 선사와의 협상력을 증진시키는 데 기여할 것이다.

• 한국지진공학회논문집
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• 제5권4호
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• pp.97-105
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• 2001

고무제품에 근간을 둔 면진장치는 상당한 저온효과와 약간의 변형도 속도효과를 보여준다. 면진장치의 비탄성거동에 영향을 미치는 이들의 속성은 면진장치의 거동을 정확히 모델링하기 위해 반드시 고려되어져야 하기 때문에, 고무와 납 모두에 영향을 미치는 저온효과와 변형도 속도효과를 고려할 수 있는 해석모델을 제시하였다. 얼린 면진장치를 일정 수직하중에서 수평방향 반복하중을 가한 실험결과들로부터 시스템 식별(SI : system identification)을 적용하여 해석모델에 필요한 고무와 납의 매개변수들을 구하였다. 제안된 해석모델은 면진장치의 거동을 유사하게 표현할 수 있음을 보여준다.

• Transactions on Electrical and Electronic Materials
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• 제15권2호
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• pp.77-80
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• 2014

The effect of reactive diluents on the ac electrical treeing in epoxy/nanosilicate systems was studied, in a needle-plate electrode geometry. Diglycidyl ether of bisphenol A (DGEBA) type epoxy was used as a base resin, and layered silicate was used as a nano-sized filler. Polyglycol (PG) or 1,4-butanediol diglycidyl ether (BDGE) was introduced as a reactive diluent to the DGEBA/nanosilicate system, in order to decrease the viscosity of the nanocomposite system. PG acted as a flexibilizer, and BDGE acted as a chain extender, after the curing reaction. To measure the treeing propagation rate, a constant alternating current (ac) of 10 kV/4.2 mm (60 Hz) was applied to the specimen, in a needle-plate electrode arrangement, at $30^{\circ}C$ of insulating oil bath. When 10 kV/4.2 mm (60 Hz) was applied, the treeing propagate rate in the DGEBA system was $1.10{\times}10^{-3}$ mm/min, and that in the DGEBA/PG system was $1.05{\times}10^{-3}$ mm/min. As 1.5 wt% of nanosilicate was added to the DGEGA/PG system, the propagation rate was $0.33{\times}10^{-3}$ mm/min. This meant that the nano-sized layered silicates would act as good barriers to treeing propagation. The effect of chlorine content was also studied, and it was found that chlorine had a bad effect on the electrical insulation property of the epoxy system.

• Journal of Pharmaceutical Investigation
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• 제26권2호
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• pp.99-103
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• 1996

Effects of glycerin and PEG 400 in donor and receptor solutions upon skin permeation of drug were investigated. Deoxycortisone was used as a model compound. In vitro skin permeation study with freshly excised hairless mouse skin was performed and the steady-state skin permeation rates of the drug were determined in different fractions of glycerin or PEG 400 in donor and receptor solutions. Glycerin in donor solution didn't show any effect on the skin permeation rate of deoxycortisone. However glycerin in receptor solution showed significant effect on the skin permeation rate of the drug. In glycerin, there's a critical concentration for balancing hydration and dehydration of skin. At low concentration, less than 20 %, glycerin showed the enhancement of the flux due to the hydration effect of skin. At high concentration, more than 30 %, glycerin retard the permeation rate which might be due to the dehydration effect on the dermis layer. Since dermis has more water content than the stratum corneum, the steady state skin permeation rates were more influenced when glycerin was in receptor solution than that of in donor solution. PEG 400 aqueous solutions doesn't affect the steady state permeation rate of deoxycortisone significantly.