• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.1093-1096
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• 2008

This study investigated the bond behavior between recycled coarse aggregate (RCA) concrete and deformed reinforcing bars. The position (i.e., vertical, horizontal) and the location (i.e., 375mm, 225mm and 75 mm) of deformed bar were considered as a main test parameter in this paper. From the test results, it was found that maximum bond strength of top reinforcement was decreased compared with that of bottom reinforcement. Also bar embedded horizontally 225mm above from base could not satisfy bond strength requirement provided in CEB-FIP code. It was caused by the fact that bonded area at the bottom of horizontal reinforcement was significantly reduced by the poring water and laitance. In this specimen, the bond strength provided by bearing stress and wedging action of concrete was not fully observed.

• The Journal of Engineering Geology
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• v.30 no.4
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• pp.673-682
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• 2020

The ground shear force at the expected failure surface and resistance force due to reinforced anchor can act as important factors according to a failure type from the stability viewpoint at a slope. Furthermore, the anchor's axial force may vary at an anchor-reinforced slope due to ground weathering, settlement, and corrosion in the incompletely anti-corrosion treated steel wire strand at a ground where the bearing plate is installed. However, in case that the resistance force of the anchor is locally lost due to the variation of the anchor's axial force, the resistance force may not play the role so that the external force tends to be transferred to the surrounding anchors, causing an increase in the tensile force in the surrounding anchors. Accordingly, a stability problem at the entire slope may occur, which requires much attention. Thus, this study proposed a method to monitor a variation trend of the tensile force of anchors installed at a slope and infer the external stability at the entire slope considering the monitoring result.

• Journal of the Korean earth science society
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• v.21 no.1
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• pp.59-66
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• 2000

In Kyeongsang basin, there were very dynamic magmatic activities, resulting to form volcanic and plutonic rocks. A plutonic recycle appeared in this region. Presumption of the pressure for hornblende-bearing granitic rock among the plutonic rocks, can support important informations for the emplacement depth of Cretaceous Bulgugsa granites in Kyeongsang basin. $Al^T$(Al total) contents of hornblende is related to the pressure, oxygen fugacity, and compositions of other minerals having the solid solution. So we apply the $Al^T$ content of hornblende to several empirical and experimental geobarometer systems to presume the pressure and to determine the emplacement depth of Cretaceous Bulgugsa granites in Kyeongsang basin from the inferred pressure. With the result that we applied the $Al^T$ contents of hornblende to the various geobarometers, there was a positive relationship between the pressure and $Al^T$. The minimum pressure value ranges from 0.73 to 1.70kbar in Kyeongju and the maximum value from 2.02 to 3.16kbar in Kimhae. And then the tectonic setting in Kyeongsang basin has no relation to the emplacement depth of Cretaceous granites and means variations with the movement of vertical component in each area. As we suppose that the density of earth's crust is $2.8g/cm^3$, the average values of the emplacement depth ranges in each area range from 2.6 to 11.4km. These data confirm the previous idea about the emplacement depth of Cretaceous granites in Kyeongsang basin, and these geobarometers using the $Al^T$ contents of hornblende is available though they have much limits. Therefore Cretaceous Bulgugsa granites in Kyeongsang basin was the shallow depth intrusive rut and the exposed granites was the shallow depth crust.

• Women's Health Nursing
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• v.7 no.3
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• pp.331-347
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• 2001

The purpose of this study was to compare the effects on labor pain and duration of delivery time for primipara women treated by Hob-Gog (LI-4) pressure. 1. The proposed hypothesis was that 'the score of labor pain could be lower in the group which had LI-4 pressure applied than in the control group'. 1-1. The sub hypothesis was that the score of subjective labor pain would be lower in the group which had LI-4 pressure applied than in the group which did not have LI-4 pressure applied. 1-2. Another sub hypothesis was that the score of objective labor pain would be lower in the group which had LI-4 pressure applied than in the group which did not have LI-4 pressure applied. 2. The proposed hypothesis was that 'the score of duration of delivery time could be shorter in the group which had LI-4 pressure applied than in the control group'. The design of this study was a nonequivalent control group non-synchronized post test only design to verify the effect on labor pain for primipara women treated by LI-4 pressure and to evaluate the benefits of using LI-4 pressure on some women and judging the degree of their labor pains in comparison with other primipara women not treated with LI-4 pressure. The subjects included 63 primipara women who underwent vaginal delivery, who were between 38-41 weeks intra uterine pregnancy; who did not have any complications; and who were under pitocin augmentation or induction. They were recruited with informed consent; 34 were in the control group and 29 were in the experimental group. The study was measured with a structured questionnaire consisting of general characteristics, knowledge related to delivery, subjective (Johnson, 1974) and objective(McLachlan, 1974) labor pain scale, data collection was done by research during the period from April, 2000 to July, 2000 and data was analyzed by descriptive statistics, $x^2$-test, and t-test. The results were as follows: 1. The scores of total labor pain in the group which had LI-4 pressure applied were lower($347.62{\pm}49.84$) than in the group($411.02{\pm}55.79$) which did not have LI-4 pressure applied; And these differences were statistically significant(t=4.7193, p=.000). 1-1. The scores of subjective labor pain in the group which had LI-4 pressure applied were lower($203.44${\pm}33.88$)$ than in the group ($$233.82{\pm}31.31$$) which did not have LI-4 pressure applied(t=3.6953, p=.000). 1-2. The scores of objective pain in the group which had LI-4 pressure applied were lower ($144.18{\pm}29.12$) than in the group which did not have LI-4 pressure applied($177.20{\pm}35.01$). but there were no statistically significant differences found in regard to the scores of objective pain(t=4.0271, p=.000). 3. The duration of delivery time in the group which had LI-4 pressure applied was shorter ($390.51min{\pm}111.91$) than in the group ($460.44min{\pm}190.78$)which did not have LI-4 pressure applied and the duration of delivery time in the experimental group was statistically more significant than that in the control group. therefore this thesis was adapted(t=1.734, p=.0879). It could be concluded that LI-4 pressure is effective in relation to labor pain and duration of delivery time for primipara women. Therefore it is necessary to increase the number of subjects to generalize this result.

• The Journal of the Petrological Society of Korea
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• v.3 no.1
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• pp.1-19
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• 1994

We present petrography, mode and chemistry data for Fe-Ti oxide minerals from the Mesozoic granitoids in South Korea. Magnetites from the Daebo Uurassic) granites are nearly pure $Fe_3O_4$, while those from the Bulgugsa (Cretaceous) granites contain considerable amounts of Mn and Ti. This is probably related to rapid cooling of the Bulgugsa granites compared with slow cooling of Daebo granites, which is supported by geologic relations and hornblende geobarometry results of Cho and Kwon (1994) on the emplacement depth for these granites. The composition of ilmenite does not shew appreciable difference between the Daebo and Bulgugsa granites. However, $Fe_2O_3$ contents are higher for the ilmenites coexisting with magnetite than for those without magnetite. In the temperature vs. oxygen fugacity diagram, the Bulgugsa granites plot near Ni-NiO and QFM buffer curves, although only two samples show greater than the granite solidus temperature. The mode data suggest that both magnetite- and ilmenite-series exist in Daebo and Bulgusa granites from the Kyonggi massif, Ogcheon belt and Youngnam massif, while only magnetite-series exists in Bulgugsa granites from the Kyongsang basin. Many ilmenite-series granites occur in the Ogcheon belt, which might be related to assimilation of carboniferous sediments in the belt. The proportion (44 : 56) between ilmenite- and magnetite-series for the Daebo granites is significantly different from that of Ishihara et al. (1981) who showed, using magnetic susceptibility data, predominance of ilmenite-series (more than 70%) for the Daebo granites, which can be mainly attributed to preference in sampling and to wrong assignment of age for some plutons. We also found magnetite in weakly-magnetized Kanghwa granite which was formerly classified as ilmenite-series by Ishihara et al. (1981). The proportion of ilmenite-series increases in the order of hornblende biotite granite, biotite granite and two mica granite. We conclude from these observations that the ilmeniteseries granites might have originated from contamination of carboniferous crustal material and/or such source material.