• Journal of Nutrition and Health
• /
• v.27 no.6
• /
• pp.574-582
• /
• 1994

The effects of age and dietary fatty acid composition on prostagladin production was investigated in Sprague-Dawley strain male rats. Animals weighing 88.6$\pm$2.2g were fed 10% dietary fat(W/W, 20% of total energy). The P/S ratios of dietary lipid were three levels(0.5, 1, 2) and there were three different levels of n-6/n-3 fatty acid ratio(2, 4, 8) in each P/S ratio. The experimental period were 1 month and 12 months, respectively. The results of this study were as follows. As the age of rats increased, the plasma thromboxane B2 production increased, but aorta 6-keto prostaglandin F1$\alpha$ decreased. When a higher amount of n-3 fatty acid was fed in each P/S ratio, the relative percentage of linolenic acid and EPA in platelet increased.

• Journal of the Korean Wood Science and Technology
• /
• v.49 no.4
• /
• pp.287-298
• /
• 2021

Torch ginger (Etlingera elatior Jack) is a potential source of lignocellulose material for various derivative products. This study aims to determine the chemical components, ratio of syringyl to guaiacyl units (S/G) in lignin, and crystallinity of the biomass of torch ginger. The effects of soda pulping on the chemical characteristics of torch ginger pulp were also studied. Pulping of the chips was conducted with active alkali of 15%, 20%, and 25% and a Liquor-to-Wood (L/W) ratio of 4:1, 5:1, and 6:1. The impregnation and pulping times at maximum temperature (170℃) were 120 and 90 min, respectively. To assess the effect of treatments on the properties of pulping, a two-factorial experimental design was applied. Results showed that the content of α-cellulose and hemicellulose in the torch ginger was 48.48% and 31.50%, respectively, with an S/G ratio of 0.70 in lignin. Soda pulping changed the crystalline structure of the biomass from triclinic to monoclinic. Active alkali, L/W ratio, and interactions considerably influenced the observed responses. The degree of delignification increased with an increase in the loading of active alkali, which lead to a decrease in the kappa number of the pulp. An active alkali content of 25% and an L/W ratio of 6:1 resulted in the highest delignification selectivity with a kappa number of 2.78 and a yield of 24%. Given its cellulose content and ease of pulping, torch ginger can be a potential raw material for derivative products that require delignification as pretreatment. However, the increase in cellulose crystallinity should be considered when converting torch ginger to bioethanol.

• Journal of Nutrition and Health
• /
• v.27 no.7
• /
• pp.687-698
• /
• 1994

The effects of age and dietary fatty acid composition on lipid metabolism were investigated in Sprague-Dawley strain male rats. These animals weighing 88.6$\pm$2.2g were fed 10% dietary fat(W/W, 20% of total energy) with 0.5, 1, 2 P/S ratio and in each P/S ratio there were three different levels of n-6/n-3 fatty acid ratio ; 2, 4, 8. The experimental period was 1 month, 6 months and 12 months. The results of this study were as follows. The body weight of rats increased rapidly for the first two months, then increased slowly until 7 to 8 months. After 10 months of dietary regimen their weight decreased. The weight of liver, kidney and epidydimal fat pad increased along with the body weight and then decreased in the 12 months. Plasma total lipid increased with age and it decreased significantly when P/S ratio of dietary fatty acid was high. In creased with age and it decreased significantly when P/S ratio of dietary fatty acid was high. In creasing n-3 fatty acid intake in each P/S ratio resulted in lower plasma total lipid although was not statistically significant. The amount of plasma total cholesterol increased at 6 months, but decreased at 12 months. In case of 1, 12 months, increasing P/S ratio significantly plasma total cholesterol and LDL-cholesterol were decreased and hepatic cholesterol was increased, VLDL-HDL-cholesterol did not changed. The n-6/n-3 ratio did not affect any of theses. The amount of plasma triglyceride and VLDL-triglyceride increased at 6 month then decreased. When the rats consumed higher amount of n-3 fatty acid in each P/S ratio, their plasma triglyceride and hepatic triglyceride increased at 1, 12months.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.13 no.4
• /
• pp.92-99
• /
• 2005

A closed-circuit type wind tunnel is designed, which has a test section with the dimensions $1.2(W){\times}1.2(H){\times}3.4(L)$. A subsonic wind tunnel is designed to improves educational circumstances and promote ground tests. It is constituted of an exchangeable test section, first and second diffusers, a fan, a settling chamber, a contraction, and 4 corners. The maximum velocity in the test section is 70m/s and the contraction ratio is 6.25:1. Input power in the wind tunnel is about 96.1 kw (128.8 hp) and its energy ratio is 3.89. It has the dimension of about $7.4(W){\times}3.6(H){\times}21.7m(L)$. The wind tunnel designed in this investigation will be an effective educational and investigational equipment.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.4 no.3
• /
• pp.113-118
• /
• 1980

Stresses were calculated for finite-width orthotropic laminates with a circular hole and remote uniaxial loading using a two-dimensional finite-element analysis with both uniform stress and uniform displacement boundary conditions. Five different laminates were analyzed: quasi-isotropic [0.deg./.+-.45.deg./90.deg.].$\_$s/, 0.deg., 90.deg., [0.deg./90.deg.]$\_$s/, and [.+-.45.deg.]$\_$s/, Computed results are presented for selected combinations of hole diameter-sheet-width ratio d/w and length-to width ratio L/w. For small L/w values, the stress-concentration factors K$\_$tn/ were significantly different for the uniform stress and uniform displacement boundary conditions. Typically, for the uniform stress conditions, the K$\_$tn/ values were much larger than for the infinite-strip reference conditions; however, for the uniform displacement conditon, they were only slighty smaller than for this reference. The results for long strips are also presented as width-correction factor. For d/w.leg.33, these width-correction factors are nearly equal for all five laminates.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.6
• /
• pp.105-113
• /
• 2006

This paper presents the results of an experimental investigation carried out to evaluate the mechanical properties of concrete mixtures in which fine(S) and coarse(G) aggregate was fully replaced with fly ash(FA). And flowability reduction problem in a large amount of fly ash concrete settled addition water($W_f$) in concrete mixture. In the test, water-cement ratio($W_c/C$) was 0.35, 0.45, and water-fly ash ratio($W_f/FA$) was 0.35, 0.45. The fly ash replacement is two different method of P and Q. The P method is mix property that the fly ash and addition water($W_f$) weight is equal to the aggregate weight [ $FA+W_f$ = G (or S)]. The Q method is mix property that fly ash is equal to aggregate weight, and added addition water($W_f$) [$FA+W_f$ > G (or S)]. Test were performed for properties of fresh concrete and compressive strength were determined at 3, 7, 28 and 91 days. The result, compressive strength was improvement that $W_c/C=0.35$, $W_f/FA=0.35$ and fine aggregate replacement in P method series than others. The flowability at Q method was improvement result than P method, but compressive strength was not. Test results indicate significant improvement in the strength properties and flowability of plain concrete by the inclusion of fly ash as fully replacement of fine and coarse aggregate, and can be effectively the fly ash replacement method.

• The KSFM Journal of Fluid Machinery
• /
• v.15 no.3
• /
• pp.32-38
• /
• 2012

This paper is aimed to propose the design database(DB) of the inline micro-turbine for 5kW class. CFD analysis is performed to investigate the effect of a turbine on each parameter. This study showed that RadhaKrishna's data is different from the 5kW class in the low-head and the micro-turbine. Therefore, new DB for the design of inline micro-turbine for 5kW class could be needed. This study configured new design DB for the design of inline micro-turbine for 5kW class. The DB of this study showed that the optimal hub ratio(Dp/DR), the optimal body ratio(Db/DR) and the optimal range of body length ratio(Lh/DR) is 50%, 1.1 and 2.3 to 2.9, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.20 no.1
• /
• pp.52-63
• /
• 1994

It was investigated that the effects of surfactant to cosurfactant ratio on the stability and rheological properties of o/w microemulsion. The stability of microemulsion was good in the surfactant to cosurfactant ratio 20/40 - 30/30. In the point of rheological properties, a yield stress meande the inner structure formation was detected and the area of hysteresis loop was increased with increasing of surfactant content of the ratio. The microemulsion prepared by the Microfluidizer was characterized by rheopetic.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1997.10a
• /
• pp.143-150
• /
• 1997

The maturity concept was adopted to predict the strength of concrete, which was subjected to same temperature conditions and variable curing conditions. Penetration test and compressive test were conducted to measure the initial and final setting time and the compressible strength of concrete specimen, respectively. Also, the temperature and time were recorded at some intervals of time for calculating the maturity. The initial and final setting were delayed as the w/c ratio increased and curing temperature decreased. The activating energy decreased as the w/c ratio increased. The relationships at the relative strength and the maturity were proposed at different w/c ratio for the same temperature curing condition, and these were applied for the variable curing conditions. The results indicated that the difference between the strength of the proposed and the specimen was big at 1 days's age but quite similar after 3 day's age.

• International Journal of Automotive Technology
• /
• v.7 no.4
• /
• pp.385-390
• /
• 2006

A fast response $CO_2$ analyzer has been developed to study transient characteristics on an SI engine. The analyzer has the delay time of 4.5 ms and time constant of 2.8 ms, which is fast enough to measure $CO_2$ concentration on a transient condition. Wide range of A/F(Air/Fuel) ratio can be estimated using the analyzer with an additional switch type oxygen sensor. The results of measurement of $CO_2$ concentration and A/F ratio on a transient condition including rapid acceleration/deceleration and EGR(Ehxaust Gas Recirculation) on/off are presented and compared with a commercial exhaust gas analyzer and UEGO(Universial Exhaust Gas Oxyzen) sensor.