• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.1
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• pp.41-45
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• 1983

The method of intestinal Ca absorption in rats was studied by injecting the test solution of $^{45}Ca$ into ligated ileal loops (an in situ closed gut sement technique). The amount of Ca absorbed was measured in regard to the amount of soluble $^{40}Ca$ and $^{45}Ca$ which disappeared from the ligated ileal loops for 30min, and appeared portal blood for 15 min after the injection. The 15~20cm ligated segment of mid ileum and the test solution containing $0.2{\sim}0.5{\mu}Ci$ $5{\mu}g$ Ca/0.5ml, pH 7.0, $37^{\circ}C$ are appropriate for this in situ closed gut segment technique which turn out to be highly available for study of Ca absorption. The rats fed casein diet absorbed more Ca by 2~5 times than the rats fed egg albumin diet.

• International Journal of Highway Engineering
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• v.6 no.3 s.21
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• pp.1-7
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• 2004

Roads, like bikeways, parkways and walks, are to be just capable of supporting light traffic and traveling public, but they are required to be human friendly and environmental-oriented. Lately soil-solidifier mixture, a kind of soil-cement, has developed and has been applied to the recycling and environment-oriented pavement as the surfacing material. Soil-solidifier pavement structure has been designed by only experience. To design this pavement mechanically, it is necessary to find out basic engineering properties of soil-solidifier mixture. This study focuses on finding out mechanical characteristics of the mixture according to mixture proportions and aging. Test molds with various mixture proportions are made, and then unconfined strength tests are performed for test molds with aging of the mixture. As the result of this study, it is found that the strength of the mixture increases with amount of cement and that maximum strength is achieved at 6%$\sim$8% of the ratio of solidifier and water. The strength increase rapidly until 14 days, after then slowly. After 28 days the strength of the mixture approaches to the constant value. The heat of hydration during curing of the mixture is measured no significantly. It also shows that temperature characteristics of the mixture is similar to that of soil. Since this mixture is mixed with soil and is able to improve engineering problems in pavement due to temperature, this mixture is expected to use effectively in the environment-oriented pavement for light traffic.