• 한국전산유체공학회:학술대회논문집
• /
• 2002.10a
• /
• pp.121-126
• /
• 2002

Aircraft propulsion systems often use diffusing S-duct to convey air flow from the wing or fuselage intake to the engine compressor, Well designed S-duct should incur minimal total pressure losses and deliver nearly uniform flow with small transverse velocity components at the engine compressor entrance. Reduced total pressure recovery lowers propulsion efficiency and nonuniform flow conditions at the engine face lower engine stall limits. In this study, S-duct which has maximum total pressure recovery and nearly uniform flow profiles at the compressure intake should be found using design optimization methods with 3-dimensional Wavier-Stokes analyses.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.6
• /
• pp.803-811
• /
• 2009

The chemical composition and water extractable dry matter (DM) of foliages from Erythrina (Erythrina variegata), Fig (Ficus racemosa), Jackfruit (Artocarpus heterophyllus), Jujube (Ziziphus jujuba Mill), Kapok (Ceiba pentandra) and Mango (Mangifera indica) and the feed intake, digestibility and N retention when feeding these foliages were studied in two experiments. In Experiment 1, 12 male goats, 3.5 months old and weighing 14.6 kg, were randomly allocated to a diet consisting of one of the foliages in a change-over design with three periods. The foliages were offered ad libitum at the level of 130% of the average daily feed intake. The Erythrina foliage had a low content of DM and condensed tannins (CT) and a high concentration of crude protein (CP) in leaves plus petioles (193 g/kg DM) and stem, while the Mango foliage had a low CP (69 g/kg DM) and high DM content. The other foliages were intermediate. High content of CT was found in the leaves plus petioles of Jackfruit foliage and in the stem of Fig and Mango foliage. There was a difference in feed intake, nutrient intake, apparent digestibility and N retention between the foliages, with Erythrina, Jackfruit and Kapok foliage being significantly higher in these parameters than Fig, Jujube and Mango foliage. The water extractable DM could be used to estimate N retention, but not DM digestibility in this study. In Experiment 2, 4 male goats weighing 13.4 kg and 6 months old were allocated to a 4${\times}$4 Latin square design. The treatments were: water spinach ad libitum and Fig, Jujube or Mango foliage ad libitum +0.5% of BW as water spinach DM. Feed intake, apparent digestibility and N retention were not significantly different among the foliage diets, but higher than for water spinach alone (p<0.05). Supplementation with water spinach to a diet consisting of low quality foliages such as Fig, Jujube and Mango, increased DM and CP intake, apparent digestibility and N retention, compared to feeding these foliages as sole feeds.

• Journal of the Korean Society of Food Culture
• /
• v.26 no.1
• /
• pp.94-99
• /
• 2011

We examined the relationship between breakfast eating, nutrient intake, and health outcomes using dietary intake, anthropometric, and biochemical measurements in Korean adults. Data from the 2007 National Health and Nutrition Survey were obtained, and 2,514 adults aged 20 to 64 years were analyzed. The prevalence of skipping breakfast, using a 24-hour diet recall, was 54.5% in the 20-29 age group, 31.2% in the 30-49 age group, and 19.2% in the 50-64 age group. In the 20-29 age group, waist circumstance and serum cholesterol were significantly higher in breakfast skippers than in breakfast eaters. In the 30-49 age group, breakfast skippers had higher triglyceride levels than breakfast eaters. Energy intake of breakfast skippers in every age group was significantly lower than that of breakfast eaters. Furthermore, in the 20-29 and 30-49 age groups, the percent of energy from carbohydrates in breakfast skippers was significantly lower than that of breakfast eaters, whereas the percent of energy from lipids in breakfast skippers was significantly higher than that of breakfast eaters. Additionally, in the 20-29 and 30-49 age groups, breakfast eaters showed higher carbohydrate and iron intake per 1,000 kcal than breakfast skippers and lower lipid intake per 1,000 kcal than that of breakfast skippers. Breakfast skippers showed intakes of less nutrients than EAR was higher than breakfast eaters except vitamin B2 and calcium intake in males of the 20-29 age group. In conclusion, nutrition education, and policy should be implemented to teach the importance of breakfast, appropriate dietary intake, and proper food choice for each age group.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.3
• /
• pp.977-985
• /
• 2012

Performance optimization of a small engine intake port has been studied through computational and experimental approach. Port angle, flange area and port shape are very important design parameters affecting performance of an intake port. Especially, radius of curvature of intake port inner surface has major effect on the flow coefficient of an intake port. As increasing port angle and flange area, flow coefficient is increased because pressure distribution and pressure gradient in the intake port are improved. Even though computational results over-predict maximum 8% compared with experimental result, they describe the tendency of flow coefficient according to the design parameters. Optimized intake port shows about 4.5% improved flow performance.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.5
• /
• pp.725-732
• /
• 2007

The effects of supplementing Gamba grass (Andropogon gayanus) with varying levels of hay from cassava (Manihot esculenta Crantz) and dried cassava root chip on growth and diet digestibility were studied using local male goats with an average initial body weight of 14.0 kg. Thirty-two animals were allocated to a completely randomized $2{\times}2$ factorial design with eight animals per treatment. The factors were two levels of cassava hay (25% and 35% of an expected dry matter (DM) intake of 3% of body weight) and cassava root chips (0 or 1% of body weight) on an individual basis with grass offered ad libitum. Another four animals were assigned to a $4{\times}4$ Latin square design to study digestibility, and were given the same four diets as in the growth experiment. Total DM intake was significantly higher in the group fed diets with cassava hay and root while the DM intake of Gamba grass was not significantly different between treatments. The supplementation with cassava hay and root increased the apparent digestibility of DM, organic matter and N and resulted in a higher N-retention. The apparent digestibility of neutral detergent fibre and acid detergent fiber was not affected significantly. The average daily gain of animals fed diets supplemented with both cassava hay and root was significantly higher than for the animals supplemented with cassava hay alone. The highest daily gain recorded was 70 g/day. In conclusion, supplementing a basal diet of Gamba grass with cassava hay and root chips improved DM intake, digestibility, N-retention and weight gain. In order to minimize the waste of cassava hay, the inclusion level of cassava hay can be recommended to be 25% of expected DM intake, which would give acceptable intake and growth performance when cassava root is included in the diet.

• International Journal of Advanced Culture Technology
• /
• v.3 no.1
• /
• pp.1-12
• /
• 2015

The current scenario of the transportation sector reflects the urgent need to address issues such as depletion of traditional fuel reserves and ever growing pollution levels. Researchers around the world are focussing on alternatives as well as optimisation of currently employed devices to reduce the pollution levels generated by the commonly used fuels. One such optimisation involves the study of air flow within the intake manifolds of SI engines. It is a well-known fact that alterations in the air manifolds of engines have a significant impact on the engine performance parameters, fuel consumption and emission levels. Previous works have demonstrated the impacts of runner lengths, diameter, plenum volume, taper angle of distribution manifolds and other factors on in-cylinder fluid motion and engine performance. However, a static setup provides an optimal configuration only at a specific engine speed. This paper aims to investigate the variations in the same parameters on a four stroke, naturally aspirated single cylinder SI engine through varying the cross section design over the intake runner with the aid of Computational Fluid Dynamics. The system consists of segments that form the intake runner with projections on the inside that allow various permutations of the intake runner segments. The various configurations provide the optimised fluid flow characteristics within the intake manifold at specific engine speed intervals. The variations such as turbulence, air fuel mixing are analysed using the three dimensional CFD software FLUENT. The results can be used further for developing an automated or manually adjustable intake manifold.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.283-290
• /
• 2007

Recently, plastic products in air-intake parts of automotive engines have become very popular due to advantages that include reduced weight, constricted cost, and lower intake air temperature. However, flow-induced noise in air-intake parts becomes a more serious problem for plastic intake-manifolds than for conventional aluminum-made manifolds. This is due to the fact that plastic manifolds transmit more noise owing to their lower material density. Internal aerodynamic noise from an Idle Speed control Actuator (ISA) is qualitatively analyzed by using a scaling law, which is expressed with some flow parameters such as pressure drop, maximum flow velocity, and turbulence kinetic energy. First, basic flow characteristics through ISA passage are identified with the flow predictions obtained by applying Computational Fluid Dynamics techniques. Then, the effects on ISA passage noise of each design factors including the duct turning shape and vane geometries are assessed. Based on these results, the preliminary low noise design for the ISA passage are proposed. The current method for the prediction of internal aerodynamic noise consists of the steady CFD and the scaling laws for the noise prediction. This combination is most cost-effective, compared with other methods, and therefore is believed to be suited for the preliminary design tool in the industrial field.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.8
• /
• pp.683-692
• /
• 2007

Recently, plastic products in air-intake parts of automotive engines have become very popular due to advantages that include reduced weight, constricted cost, and lower intake air temperature. However, flow-induced noise in air-intake parts becomes a more serious problem for plastic intake-manifolds than for conventional aluminum-made manifolds. This is due to the fact that plastic manifolds transmit more noise owing to their lower material density. Internal aerodynamic noise from an idle speed control actuator(ISA) is qualitatively analyzed by using a scaling law, which is expressed with some flow parameters such as pressure drop, maximum flow velocity, and turbulence kinetic energy. First, basic flow characteristics through ISA passage are identified with the flow predictions obtained by applying computational fluid dynamics techniques. Then, the effects on ISA passage noise of each design factors including the duct turning shape and vane geometries are assessed. Based on these results, the preliminary low noise design for the ISA passage are proposed. The current method for the prediction of internal aerodynamic noise consists of the steady CFD and the scaling laws for the noise prediction. This combination is most cost-effective, compared with other methods, and therefore is believed to be suited for the preliminary design tool in the industrial field.

• Women's Health Nursing
• /
• v.22 no.4
• /
• pp.297-307
• /
• 2016

Purpose: This study was to estimate salt preference and sodium intake of pregnant women, and identify the relationship between salt preference and sodium intake. Methods: Research design was a cross sectional correlational survey with 197 pregnant women who visited outpatient clinics for antenatal care. The sodium intake levels were estimated by the amounts of sodium intake using the 24-hour recall method and sodium concentration in spot urine. The data were analyzed using descriptive statistics, t-test, ANOVA and Pearson's correlation. Results: Sodium intake using 24-hour recall method was $3,504{\pm}1,359mg$. Sodium intake levels had statistically significant differences depending on income. The average amount of sodium in spot urine was $2,882{\pm}878mg/day$. Sodium excretion levels had statistically significant differences depending on whether participants had preexisting hypertension in their family history and Body Mass Index (BMI) pre-conception. Salt preference was $62.61{\pm}20.96$ out of 180 points. Salt preference had significant differences depending on income, parity, gestational age, BMI pre-conception and showed negative correlation with sodium quantity in spot urine. Conclusion: Sodium intake in pregnant women recommended by World Health Organization recommended is 175%. Salt preference was not significantly different between sodium intake levels, however it was negatively correlated with sodium quantity in spot urine among pregnant women.

• Journal of Korean Academy of Nursing
• /
• v.37 no.3
• /
• pp.276-285
• /
• 2007

Purpose: This study was conducted to explore the relationship between isoflavones intake from soy foods and perimenstrual symptoms among women. Methods: The research design was a cross sectional study. Subjects consisted of 245 women living in Korea, aged 19-49 years. The measurement tools were MDQ and FFQ. Results: Frequently consumed soy isoflavones foods were rice with soybeans, soybean paste stew, and soy paste with tofu. The amounts of soy isoflavones foods consumed in order from highest to lowest were rice with soybeans, soybean paste stew, seasoned soybean sprouts, and soy paste with tofu. Subjects were divided into three groups by isoflavones intake levels; the small intake group, moderate intake group, and large intake group. There were significant differences in some menstrual symptoms, and postmenstrual symptoms by isoflavones intake levels. In general, the moderate isoflavones intake group showed lower scores in some menstrual symptoms and postmenstrual periods compared to the small and large intake groups. Conclusions: These results suggest some positive health effects of isoflavones from soy foods on perimenstrual symptoms. More accurate, objective measurement needs to be applied and more investigation of soy isoflavones effects on many aspects of women's health need to be done in a future study.