• Journal of Nutrition and Health
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• 제27권4호
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• pp.323-335
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• 1994

The present study was carried out in normocholesterolemic New Zealand white(NZW) rabbit, to evaluate the effect of dietary supplementation with Korean pinenut oil, on plasma lipids, plasma lipoproteins, liver lipids and platelet aggregation. NZW rabbits were fed for 80 days on a commercial chow diet supplemented with 5% of energy as fats(soybean oil or pinenut oil) or 10% of energy as fats(soybean oil or pinenut oil). A control group was fed a commercial stock diet. There were no significant effects of pinenut oil on plasma free cholesterol, HDL-cholesterol, triglycerides, glucose and lecithin-cholesterol acyltransferase, as compared with those obtained from rabbits fed the soybean oil diet. After 80 days, the concentration of plasma free fatty acid in only the pinenut oil group was significantly decreased by about 50% relative to the control diet. At the end of the dietary treatment, liver triglycerides and phospholipids were significantly decreased in the pinenut oil group, compared to the how diet, whereas the soybean oil-consuming rabbits had only significantly decreased phospholipid levels. Cholesterol contents of liver were unaffected by type of dietary fat. At the end of 80 days, a diet containing pinenut oil resulted in a decrease in apolipoprotein B and the apo B/apo AI ratio as compared with the stock diet or soybean oil diet. Platelet aggregation induced by collagen or arachidonic acid was depressed significantily in pinenut oil diet.

• 한국전산유체공학회지
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• 제6권1호
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• pp.1-13
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• 2001

The natural convection heat transfer and solidification in a stratified pool are studied. The flow and heat transfer characteristics in a heat generating pool are compared between single-layered and double-layered pools. And local Nusselt number distributions on outer walls are obtained to consider thermal loads on a vessel wall. The cooling and solidification of Al₂O₃/Fe melt in a hemispherical vessel are simulated to study the mechanism of heat transfer and temperature distribution. A unstructured mesh is chosen for this study because of the non-orthogonality originated from the boundaries of double-layered pool. Interface between the layers is modeled to be fixed. With this assumption mass flux across the interface is neglected, but shear force and heat flux are considered by boundary conditions. The colocated cell-centered finite volume method is used with the Rhie-Chow interpolation to compute cell face velocity. To prevent non-physical solutions near walls in case body force is large the wall pressure is extrapolated by the way to include body force. The numerical solutions calculated by current method show that averaged downward heat flux of the double-layered pool increases compared to single-layered pool and maximum temperature occurs right below the interface of the layers.

• 한국산업융합학회 논문집
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• 제2권1호
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• pp.35-43
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• 1999

The purpose of this study is to derive the optimal methodology estimating the changes of fluvial hydraulic characteristics due to semi-covering work of urban stream. First, after collecting the data of the daily maximum rainfall of Chungju gaging station, the frequency analysis was carried out with frequency factor method, which includes normal, two-parameter and three-parameter lognormal, Gumbel-Chow, pearson type III, log-pearson type III distribution, and the goodness of fit test was executed by $x^2$-test and Kormogorov-Smimov test. Using the SCS method, the effective rainfall was estimated and the peak flow was calculated by the area-routing method. The HEC-2 model was applied to calculate water surface profiles for steady, gradually varied flow at Kyohyun river system in Chungju city. The model was applied to floodplain and riverbed management to evaluate flood way encroachments and to delineate flood hazard by riverside roadway construction. The model also was used to evaluate effects on water surface profiles of river improvement and levees as well as the presence of bridges or other hydraulic structures in the floodplain.

• 한국농공학회지
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• 제17권3호
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• pp.3848-3859
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• 1975

The author attempted to find most suitable formulas for probable rainfall intensities with analysis and consideration for characteristics of rainfall intensities according to the short and long period return periods at Cheong-Joo district. Above mentioned formulas induced by this study can be contributed to the credibility of runoff estimation for urban sewerage system, drainage works in small catchment area and embankment works in the rivers. The results of this study are summarized as follows: 1 Calculation values by Gumbel-Chow method were selected as a mean values for the calculation of probable rainfall intensities according to return periods in the short period. 2. Calculations for probable rainfall intensities for long period are based upon to the result by Iwai's method. Talbot type, {{{{I= {a} over {t+b} }}}} is confirmed as a most suitable formula for probable rainfall intensities among calculation methods in the short periods at Cheong-Joo district. 4. Specific coefficient method, I24=RN24${\beta}$N was selected as a means of calculation for suitable formulas of probable rainfall intensities according to return periods in case of long period. 5. Runoff estimation with high credibility by rational formula can be anticipated by establishment for the most suitable probable rainfall intensities at Cheong-Joo district.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1993년도 추계학술대회 논문집
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• pp.137-140
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• 1993

Electrical properties and thermal annealing effects of $C_{22}$-quinolium(TCNQ) Langmuir-Blodgett(LB) films were studied. Typical current-voltage(I-V) characteristics along the perpendicular direction chow an anomalous behavior of breakdown near the electric-field strength of $10^{6}$V/cm. To see the thermal influence of the specimen, current was measured as a function of temperature(20∼$180^{\circ}C$). It shows that the current increases about 4 orders of magnitude near 60∼$70^{\circ}C$ and remains constant far a while up to ∼$150^{\circ}C$ and then suddenly drops. Such increase of current near 60∼$70^{\circ}C$ seems tn be related to a softness of alkyl chains. Besides the electrical measurements, UV/visible absorption(300∼800 nm) of the thermally annealed sample was measured to see the internal-structure change. It is found that there are four characteristic peaks. At 494 nm, the optical absorption of the thermally annealed specimen at $60^{\circ}C$ starts increase and stays almost constant upto∼ $140^{\circ}C$. And eventually it disappears above $180^{\circ}C$. After heat treatment of the specimen up to $150^{\circ}C$, Uv/visible absorption was measured while cooling.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.1894-1899
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• 2008

하천 내의 자생수목군에 의한 자연적인 흐름저항의 증가, 식재를 통한 인위적인 흐름저항의 증가, 교각 등의 구조물로 인한 흐름저항을 배수계산에 반영하기 위하여 일반적으로 Manning n값이 사용된다. 그러나 흐름 장애물로 인하여 증가된 Manning n값의 선정은 Chow(1950) 등이 제시한 도표를 활용하는 방법과 같이 공학적 판단을 요하는 작업이다. 그러므로 객관적으로 흐름저항을 산정할 수 있는 기법의 개발이 필요하며, 이를 위한 기초연구로 본 연구에서는 개수로 내 장애물의 항력계수 특성에 대하여 분석하고자 한다. 일반적으로 항력계수는 유체의 유속에 따라 변화되므로, Reynolds 수 또는 Froude 수에 따라 변화되는 것으로 알려져 있다. 그러나 그 범위가 연구자에 따라 상이하여 이를 정량화 할 필요가 있으며, 본 연구에서는 실험자료로부터 개수로 내 장애물의 항력계수 특성을 분석하고, 개수로에서 일반적으로 발생할 수 있는 Reynolds 수 또는 Froude 수 범위에서 기존 연구결과들을 비교분석하여 항력계수의 범위를 정량적으로 정립하고자 한다. 일반적인 상류 흐름조건에서 평균 항력계수($C_D$)는 1.11로 계산되었고, Froude 수의 증가에 따라 항력계수의 변동성이 점차 증가하였으며, 이러한 결과로부터 개수로 내 장애물로 인한 흐름저항을 반영하기 위하여 Manning n값으로 산정된 결과는 평균 0.01의 편차를 보이는 것으로 분석되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.552-555
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• 2005

The influence of whole yeast cells $(0{\sim}15%\;w/v)$ on the protein adsorption performance in dye-ligand chromatography was explored. The adsorption of a model protein, bovine serum albumin (BSA), was selected to demonstrate this approach. The UpFront adsorbent $(p=1.5\;g/cm^3)$ derivatised with Cibacron Blue 3GA and a commercially available expanded bed column (20 mm i.d.) from UpFront Chromatography, Denmark, were employed in the batch binding and expanded bed operation. The BSA binding capacity was demonstrated to not be adversely affected by the presence of yeast cells. The dynamic binding capacity of BSA at a $C/C_0=0.1$ biomass concentration of 5, 10, 15% w/v were 9, 8, and 7.5mg/mL of settled adsorbent, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권3호
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• pp.211-214
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• 2006

Immobilized Candida antarctica lipase was used to catalyze the separation of ketoprofen into its components by means of esterification followed by the enzymatic hydrolysis of the ester product. In this study, ketoprofen underwent esterification to ethanol in the presence of isooctane. When the reaction was complete, 58.3% of the ketoprofen had been transformed into an ester. The ketoprofen remaining in solution after the reaction was complete consisted primarily of its S-enantiomer (83.0%), while the 59.4% of the ketoprofen component of the ester consisted of its R-enantiomer. We then subjected the ester product to enzymatic hydrolysis in the presence of the same enzyme and produced a ketoprofen product rich in the R-enantiomer; 77% of this product consisted of the R-enantiomer when 50% of the ester had been hydrolyzed, and 90% of it consisted of the R-enantiomer when 30% of the ester had been hydrolyzed. By contrast, the R-enantiomer levels only reached approximately 42 and 65%, respectively, when 50 and 30% of the racemic ester was hydrolyzed under the same conditions.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권3호
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• pp.268-272
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• 2006

A dense, pellicular UpFront adsorbent ($p=1.5 g/cm^3$, UpFront Chromatography, Cophenhagen, Denmark) was characterized in terms of hydrodynamic properties and protein adsorption performance in expanded bed chromatography. Cibacron Blue 3GA was immobilised into the adsorbent and protein adsorption of bovine serum albumin (BSA) was selected to test the setup. The Bodenstein number and axial dispersion coefficient estimated for this dense pellicular adsorbent was 54 and $1.63{\times}10^{-5}m^2/s$, respectively, indicating a stable expanded bed. It could be shown that the BSA protein was captured by the adsorbent in the presence of 30% (w/v) of whole-yeast cells with an estimated dynamic binding capacity $(C/C_o = 0.01)$ of approximately 6.5 mg/mL adsorbent.

• 한국농촌생활과학회지
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• 제5권2호
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• pp.125-134
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• 1994

This study was performed to observe the effects of dietary fat levels and sources on lipids contents and cellularities of liver, brain, and adipose tissue of early weaned rats. Male Sprague-Dawley rats were prematurely weaned from postnatal 17th day with the experimental diets differ in fat levels : low(5%), medium(10%), high(20%) and fat sources : butter, soybean oil, butter＋ soybean oil. On the postnatal 29th day, contents of total lipid, triglyceride, cholesterol and phospholipid of serum, liver, brain and adipose tissue were determined, and DNA was determined to assess the cell growth. Rats early weaned fed high fat diet showed lower total lipid and triglyceride levels in serum and liver than those fed medium or low fat diet Rats early weaned fed high fat diet had adipocytes of fewer number, but larger size than those of rats fed low or medium fat diets. Rats early weaned fed soybean oil diet had more adipocytes thu those fed butter diet. Rats normally weaned to commercial chow diet showed lower total lipid, triglyceride, and cholesterol levels in serum and liver, had fewer adipocytes than all early weaned rats except for rats fed high fat-butter diet. These results suggest that high fat-butter diet is ideal weaning diet at early weaning.