• 멤브레인
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• 제28권4호
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• pp.279-285
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• 2018

이소프로필알코올/물 혼합물은 가교된 폴리비닐알코올 복합막을 이용하여 투과특성평을 알아보았다. 검화도가 다른 3종 PVA를 이용하여 고분자의 농도와 GA 농도에 따라서 투과특성을 확인하였다. 복합막은 PVA 용액을 PAN 지지체 위에 캐스팅한 후, 열가교를 통해 제조하였다. PVA 농도가 증가할수록 투과도는 감소하지만 선택도는 증가하는 것을 확인하였다. PVA-3이 7 wt% 농도로 코팅된 복합막에서 $209g/m^2h$의 투과도를 가지고, 100 이상의 선택도를 가지는 것을 확인하였다. 침지형 분리막을 제조하여 feed tank 온도와 feed 용액의 IPA 농도에 따라서 투과실험을 확인하였다. 또한 IPA 수용액에 농축실험을 지속적으로 한 결과, 60시간 후에 IPA의 농도가 99%까지 증가하는 것을 확인하였다.

• 한국수산과학회지
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• 제8권3호
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• pp.181-184
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• 1975

체장 약 10cm 되는 잉어 치어를 이용하여 염도 $20\%_{\circ}$까지의 범위내에서 실험실내 수조에서 그들의 저항성과 성장에 관한 일련의 실험을 한 결과는 다음과 같았다. 염분도 $12\%_{\circ}$까지는 담수에서 바로 옮겨도 죽지 않았으며, 낮은 염분에서 적응시켜 높은 데로 옮기니 $15\%_{\circ}$까지 대부분 잘 살아 남았다. 실험기간의 수온은 실온하에서 $14\~27^{\circ}C$의 범위내였다. 성장실험에서는 $2\~8\%_{\circ}$ 범위서는 생사료인 실지렁이를 사용했을 때나, 건조 pellet 사료를 사용했을 때나 다 같이 성장률과 사료효율이 대단히 높았다. 그러나, $12\%_{\circ}$에서는 실지렁이를 주었을 때는 아주 좋지 못했지만, pellet에서는 성장율은 조금 낮았지만 사료효율은 대단히 높았다.

• 한국수산과학회지
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• 제50권1호
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• pp.15-24
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• 2017

This study examined the effects of dietary supplementation with citrus by-product (CBP) on the growth, feed utilization, innate immunity, and histology of the gills and intestine of juvenile olive flounder Paralichthys olivaceus during low water temperature season. A vitamin C-free basal diet was regarded as a control and five other diets were formulated that contained 30 and 300 mg of L-ascorbyl-2-polyphosphate (LAPP) or CBP as vitamin C equivalents/kg diet, or the antibiotic oxytetracycline (OTC) (designated as control, LAPP30, LAPP300, CBP30, CBP300, and OTC, respectively). Olive flounder (initial body weight $44.6{\pm}0.32g$) were fed the six experimental diets to apparent satiation for 9 weeks. Growth and feed utilization were significantly higher in CBP30 than in the control and LAPP groups. The lysozyme activity was significantly higher in CBP30 than in LAPP300. Enterocyte height was significantly higher in CBP30 than in the control. The number of goblet cells was increased significantly with LAPP30, LAPP300, and CBP30. These results demonstrate that CBP can reduce or replace vitamin C and antibiotic in the diet of olive flounder during the low-water-temperature season. The optimal CBP supplementation level seems to be approximately 1%, which is equivalent to 30 ppm vitamin C/kg in the fish diet.

• Asian-Australasian Journal of Animal Sciences
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• 제3권4호
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• pp.331-336
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• 1990

In order to evaluate the adaptability of Aardi goats to arid environment, 5 Aardi bucks were deprived of water for four days during spring and summer seasons. The rise in average maximum ambient temperature from $24.8^{\circ}C$ in spring to $35.8^{\circ}C$ in summer caused a significant rise in rectal temperature ($0.3^{\circ}C$), respiratory rate (62%), serum osmolaity (8%) and serum sodium concentration (17%). While, it resulted in a significant decline in dry matter intake (50%), urine volume (74%) and fecal water excretion (60%) compared with their values in spring, but had no significant effect on the volume of drinking water. At the end of the 4-days deprivation period during spring, respiratory rate, dry matter intake and urine volume were reduced by 18, 77 and 91% relative to their average in control goats. The corresponding reduction in summer were 58, 100 and 100%. Serum osmolaity was risen by 15% in spring deprived goats and 29% in summer deprived goats. Rectal temperature rose by a mean value of $1.3^{\circ}C$ only in goats deprived of water in summer. Percent of moisture in the feces declined from 64 in control goats, to 24% in water deprived goats during spring season. The corresponding values in summer were 25 and 6%. These responses of Aardi goats deprived of water in summer indicate that they possess a water economy mechanism enable them to tolerate infrequent drinking in hot-arid environment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.470-475
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• 2012

The downstream piping system of the water supply system in a supercritical power plant is affected by the fluctuation pressure waves induced by accessing to the acoustic modes of the piping systems with the rotation and impeller passing pulsations of the feed water pump. There are the phenomena amplified at the same time in the range of 415 ~ 455Hz, 830 ~ 910Hz, 1245 ~ 1365Hz and 1660 ~ 1820Hz on the spectrums of the vibration, the sound pressure, and the pressure fluctuation waves.

• 한국어병학회지
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• 제1권2호
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• pp.131-134
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• 1988

어류에 의한 물과 멱이로부터의 물질 흡수를 연구하기 위하여 방사성 동위원소를 추적자로 이용하였다. 금붕어가 들어있는 네개의 수조에 Co-57을 처리한 후 각기 다른 온도 조건하에서 실험을 실시하였고, 또 다른 네개 수조의 어류는 동위원소를 처리한 먹이를 주었다. 실험결과로부터 수온은 물로부터의 코발트 흡수에 거의 영향을 미치지 않는 것으로 나타났다. 물에 동위 원소를 처리한 후 13일째 어류가 흡수한 코발트의 양은 총가용량의 0.0006%에 불과해 물을 통한 흡수과정은 매우 서서히 진행됨을 알 수 있었다. 먹이를 통해 어류체내에 흡수된 방사능은 90일간의 실험기간에 걸쳐 시간경과에 따라 선형 증가 양상을 보였으며, 실험 개시 후 90일째에 마리당 투여한 총 방사능의 12% 수준에서 거의 평형상태에 도달하였다.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.271-273
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• 2000

Recently, possibility of low protein diet with high energy level for improvement of fish production has been proposed in several fish species, especially under restricted feeding rate, fish responded better on high energy diet than low energy diet McGoogan and Gatlin (1999) stressed another benefit of low protein diet with high energy for fish production, in terms of reduction of nitrogen waste from fish metabolism However, others reported no effect of high lipid in feed on performance of fish (Jover et al. 1999). This was probably because that energy availability o requirement for fish varied based on fish species, protein content or quality in feed, rearing water temperature condition and feeding ration. (omitted)

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.847-852
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• 2009

Feedwater heaters of many nuclear power plants have recently experienced severe wall thinning damange, which will increase as operating time progresses. Several nuclear power plants in Korea have experienced wall thinning damage in the area around the impingement baffle inside feed-water heater installed downstream of the turbine extraction stream line. At that point, the extract steam from the turbine is two phase fluid at high temperature, high pressure, and high speed. Since it flows to reverse direction after impinging the impingement baffle, the shell wall of feedwater heaters may be affected by flow-accelerated corrosion. In this paper, to compare wall thinning range according to change entrance nozzle diameter and position with reference numerical analysis model's wall thinning range, various numerical analysis models applied. In case of changing diameter, four different diameter is applied. And a side of nozzle position, two different position-vertical type and parallel type-is applied. And then this paper describes operation of numerical analysis which is composed similar condition with real feed water heater. In conclusion, this study shows effective design for shall wall thinning by changing nozzle diameter and position.

• 한국초전도ㆍ저온공학회논문지
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• 제20권2호
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• pp.6-10
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• 2018

Removal of iron oxide scale from feed-water in thermal power plant can improve power generation efficiency. We have proposed a novel scale removal system utilizing High Gradient Magnetic Separation (HGMS). This system can be applied to high temperature and pressure area. We have conducted the lab-scale model experiments using ${\varphi}50mm$ filters and it demonstrated high removal efficiency in HGMS, but scale-up of the system is required toward practical use. In this study, we conducted a large scale mock-up HGMS experiment. We used the superconducting solenoidal magnet with ${\varphi}400mm$ bore and demonstrated that our HGMS system can achieve sufficient scale removal capacity that is required to introduce into both off-line and on-line system.

• 한국식품과학회지
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• 제9권2호
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• pp.138-143
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• 1977

메밀 전분의 이화학적 성질을 살펴본바, 입자의 크기는 4.3-11.4 미크론(평균 7.8미크론)이었다. 전분의 물결합능력은 103.7%, 아밀로스 함량은 25%이었다. 복굴절성 소실의 측정법에 의한 호화개시 및 호화 종료 온도는 각각 $61^{\circ}$ 및 $65^{\circ}C$이었고 아밀로그라프에 의한 초기 호화온도는$64.5^{\circ}C$이었다. 전분의 노화속도는 $21^{\circ}C$에서 밀 전분보다 다소 빨랐다.