• Proceedings of the Membrane Society of Korea Conference
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• 1997.06a
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• pp.159-174
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• 1997

삼투현상이란 반투막을 사이에 두소 저농도의 용매가 고농도의 용액으로 이동하는 현상으로 막양측 용매의 화학포텐셜이 같아지게 되면 용매의 이동은 정지되고 수두차 만큼의 삼투압차가 발생한다. 이 때 고농도 용액측에 삼투압차 이상의 압력을 가하게 되면 삼투현상과는 반대로 고농도 용액측의 용매가 저농도의 용액측으로 역류하는데 이를 역삼투현상이라 한다. 역삼투현상을 이용하여 물질을 분리하는 역삼투 공정은 막의 물리화학적 특성, 분리대상물질의 물리화학적 특성, 그리고 압력차를 추진력으로 하는 세가지 요소의 조합에 의해 행하여 진다. 역삼투는 분자크기에 따른 분리조작이 아니므로 정밀여과나 한외여과에서와 같은 유기물질의 침착현상이 적으며 결과적으로 막의 수명도 길어진다. 역삼투막은 용존염을 분리제거할 뿐만 아니라 분자량이 적은 유기물 및 Aromatic hydrocarbon 등의 분리조작에도 그 이용가능성이 고조되고 있다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.6 no.1
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• pp.9-14
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• 1977

• Journal of Korea Water Resources Association
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• v.32 no.2
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• pp.99-110
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• 1999

The method of moments, a Lagrangian scheme, considers the zeroth, first, and second moments of the grid cell spatial distributions of the concentration and then advects the concentration by maintaining conservation of the moments. The reasonable inital description of the first and second moments as well as the mean concentration, the zeroth moments, in grid element is important in the method of moments. In this study, the description methods of each initial moment are reviewed, and the method of moments is extended to overcome the restrictions of Courant number. Its performance is compared with those of available Eulerian and Lagrangian schemes. As the results, the method is successfully extended to overcome the stability restriction and is an accurate scheme for the advection simulation of concentration distribution, especially of which the gradient is steep. In addition, the method is very promising scheme in terms of computational efficiency when the mixing is confined in a relatively small region to the entire domain in two-dimensional problem.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.77-77
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• 2002

본 실험은 한우 종빈우의 임신말기에 Se과 Vit. E 투여가 종빈우의 분만 후 번식기능에 미치는 요인을 검토하였고, 임신말기 Se과 Vit. E 를 투여한 한우 종빈우에서 태어난 송아지의 발육능력을 조사하고, 혈액화학치와 혈중 Vit. E 농도에 미치는 영향을 검토하였다. 1. 분만 l 개월전 Se과 Vit E 을 투여한 한우 종빈우에서 태어난 송아지의 발육성적을 조사한 결과, 생시체중은 투여구가 대조구보다 높은 성적을 나타냈다 (P＜0.05). 또한 이유시 체중과 일당증체량도 투여구가 대조구 보다 다소 높은 성적을 나타냈으나 처리구간 유의적인 차이는 인정되지 않았다 (P＞0.05). 한편 종빈우의 번식능력을 조사한 결과, 투여구가 대조구보다 초발정이 빨리 도래하였고, 수태 당 인공수정 횟수도 적었으나, 처리구간 유의적인 차이는 인정되지 않았다 (P＞0.05). 2. Se과 Vit. E를 분만 2 개월전 4 회 투여한 한우 종빈우로부터 태어난 송아지의 발육성적을 조사한 결과, 생시체중, 이유시체중 및 일당증체량은 투여구가 대조구보다 높은 성적을 나타냈으나, 처리구간 유의적인 차이는 인정되지 않았다 (P＞0.05). 한편, 한우 종빈우의 번식능력을 조사한 결과, 분만 후 초발정은 투여구가 대조구보다 초발정 발현이 빨랐으며 수태 당 인공수정 횟수는 투여구가 대조구에 비해 적었으나 처리구간 유의적인 차이는 인정되지 않았다 (P＞0.05). 3. Se과 Vit. E를 분만 1개월전 2 회 투여한 한우 종빈우에서 태어난 송아지의 혈액성분에 미치는 영향을 검토한 결과, 평균 혈중 albumin 은 Vit. E 2000IU 투여구가 여타구보다 높은 성적을 나타냈으며 (P＜0.05), 평균 혈중 cholesterol이 함량 또한 Vit. E 1500IU 투여구가 여타구보다 높게 나타났다 (P＜0.05). 그러나 혈중 BUN, creatinine, glucose, IP, calcium, TP 및 triglycerides 함량은 처 리 구간 유의 적 인 차이 는 없었다 (P＞0.05). 4. Se과 Vit. E를 분만 2 개월 전 4 회 투여한 한우 종빈우에서 태어난 송아지의 혈액성분에 미치는 영향을 검토한 결과, 평균 혈중 albumin, cholesterol, BUN, creatinine, glucose, IP, calcium, TP 및 triglycerides 함량은 모든 처리구에서 유의적인 차이가 인정되지 않았다 (P＞0.05). 5. 분만 l 개월 전 Se과 Vit. E를 투여한 한우 종빈우로부터 태어난 송아지의 혈중 Vit. E 농도를 측정한 결과, 평균 혈중 Vit. E 농도는 투여구가 대조구보다 다소 높은 농도를 나타냈으나 처리구간 유의적인 차이는 없었다 (P＞0.05). 6. 분만 2 개월 전에 Se과 Vit. E를 투여한 한우 종빈우로부터 태어난 송아지의 혈중 Vit. E 농도에 미치는 효과를 검토한 결과, 투여구가 대조구보다 다소 높은 농도를 나타냈으나 처리구간 커다란 차이는 없었다 (P＞0.05).

• KSBB Journal
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• v.6 no.3
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• pp.241-247
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• 1991

The Poly (4-vinyipyridine-co-styrene) membrane containing Pyridine as fixed carrier was synthesized and characterized. And the active transport mechanism of Cl- and $CCl_3COO^-$ with changing concentration of $H^+$ and $OH^-$ was investigated. $CCl_3COO^-$ was transported not only by a symport mechanism with $H^+$ transfer but also by an antiport mechanism with $OH^-$transfer, while $Cl^-$ was transported only by a symport mechanism with $H^+$ transfer. Observing the initial flux of anions, salt formation constant between ions and membrane (K), and diffusion coefficient in membrane (D) were calculated as follows: for $Cl^-, \;K=4.60{\times}10^2\;mol^{-1}{\cdot}\textrm{cm}^3, \;D=1.57{\times}10^{-3}{\textrm{cm}^2/h$ and for $CCl_3COO^-, \;K=1.l0{\times}10^4\;mol^{-1}{\cdot}\textrm{cm}^3, \;D=1.14{\times}10^{-4}{\textrm{cm}^2}/h$.

• Journal of the Korean Data and Information Science Society
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• v.22 no.3
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• pp.413-421
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• 2011

The present study was carried out to summarize the effect of garlic in the hyperlipidemia rats by meta-analysis related studies. The association measure to test effect of garlic was the mean difference (MD). In this particular fixed-effect model of mean difference, body weight, liver weight, kidney weight and heart weight were significantly decreased (p < 0.05). Also, blood glucose, plasma total cholesterol, plasma triglycerides, LDL-cholesterol, liver cholesterol, liver triglycerides were significantly decreased. HDL-cholesterol was significantly increased. In this case of heterogeneous variable, random effect model was applied. In this model, liver weight, blood glucose, plasma total cholesterol, plasma triglycerides, LDL-cholesterol, liver cholesterol, liver triglycerides were significantly decreased. HDL-cholesterol was significantly increased. According to the meta-regression analysis, duration of injection was significantly for kidney weight, testis weight, plasma total cholesterol, plasma triglycerides, HDL-cholesterol, LDLcholesterol, liver cholesterol, liver triglycerides.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.293-297
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• 2005

This experiment was carried to investigate the optimum concentration of abscisic acid (ABA) treatment for enhancing fruit coloration of 'Kyoho' grapes. Cluster and berry weights showed a tendency that increased in proportion to concentration of ABA treatment, but were not significant in all treatments. Also, soluble solids and titratable acidity were not significant during fruit development in all treatments. L-phenylalanine ammonia-lyase (PAL) activity showed a tendency that decreased after rapidly increased in all treatments, and was the highest in 1000 mg/l ABA treatment at final harvest. Anthocyanin and total phenolics contents were high in proportion to ABA treatment concentration, and anthocyanin content in 1000 mg/l ABA treatment was 2.5 folds of that in control. Fructose and glucose as soluble sugars were detected, but sucrose was not detected. Both fructose and glucose contents increased during fruit development, but showed little difference in all treatments.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.4
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• pp.398-407
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• 2020

The inhibitory effect on α-glucosidase, a marker of postprandial hyperglycemia, and angiotensinconverting enzyme (ACE), a marker of hypertension, was analyzed using non-fermented green tea and three different types of fermented tea, which are popular beverages in modern life. Green tea was mixed with trace amounts of vanadate (50 ㎍/mL), which has insulin-mimetic effects, to investigate the synergistic effect of vanadate on the inhibition of α-glucosidase. The concentration of epigallocatechin gallate (EGCG) and caffeine was also checked. The extracts of green tea and fermented teas showed clear inhibition on α-glucosidase, which caused a decrease in the postprandial glucose levels. The inhibitory effect was most prominent in the 20% fermented tea. Trace amounts of vanadate (50 ㎍/mL)-mixed green tea extract had twice the inhibitory effect on α-glucosidase than the pure tea extract. All teas showed inhibitory effects on ACE. Among those, the effect was most prominent in green tea, which had higher concentrations of EGCG. In contrast, the postprandial glucose-lowering effect and ACE inhibition of the fermented teas, which have a lower level of EGCG, was attributed to some other different functional substances.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.2
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• pp.125-128
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• 2014

The objective of this study is to investigate the changes in levels of odorous compounds in pig slurry during different seasons. Slurry from pens of finishing pigs was sampled every 4-wk and concentration of odorous compounds was analyzed. There was no difference in the range of phenols level (123 to 156 ppm) during spring (April to May), summer (July to August) and fall (October to November). The concentration of indoles was higher (P<0.05) during spring (14.3 ppm) than summer and fall (5.4~7.6 ppm). Level of BCFA ranging from 727 to 1,194 ppm was not different at any season. Among SCFA, there was no difference in propionic acid during any season but levels of acetic acid and butyric acid were highest (P<0.05) during spring season. Concentration of odorous compounds in pig slurry was highest during spring season. Interestingly, it tended to be lower during summer season compare to fall. This result might be due to relatively lower ventilation rate in order to maintain a constant temperature during spring season. Further study will be necessary to determine the relationship between the concentration of odorous compounds and ventilation system.

• The Korean Journal of Rheology
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• v.9 no.1
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• pp.40-46
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• 1997

폴리이소부틸렌(PIB)/폴리부텐(PB) 고분자 용액에 분산된 입자의 영향을 살펴보기위 해 제조된 kaolinite/PIB/PB 용액에 대한 Weissenberg 효과와 유변학적 물성을 조사하였다. Kaolinite 분산 PIB/PB 고분자 용액도 2차 유체로 간주될수 있음이 발견되었으며 느린 변형 속도에서 2차유체로 간주되는 입자 분산 고분자 용액에 대한 막대상승 실험에서 얻는 고분 자 용액의 탄성 발현에 의한 상승높이에 비례하는 막대오름상수 $\beta$값으로부터 유변학적 특 서치들을 구할수 있었다. 이러한 막대오름상수 $\beta$값은 PIB/PB 및 kaolinite/PIB/PB계에서 용매 점도, 입자 농도와 PIB의 농도가 높을수록 증가하는 반면 온도에는 반비례함을 보이는 데 고분자 용융체에서와는 달리 입자 분산고분자 용액의 경우 입자의 농도가 증가함에 따라 탄성도 증가하는 특징적 거동을 관찰하였다. 한편 Physica MC-120과 RMS 800 Rheometer 를 사용하여 PIB 고분자 용액의 유변학적 물성들을 측정하였으며 2차 유체 구성방정식에 근거하여 얻어지는 유변학적 특성치들과 비교하였다.