• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.230-231
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• 2014

This study is concerned with the root penetration resistance competence and constructability of a waterproofing and root penetration resistance layer of an eco-bridge which is applied with various types of seeding. For the review of root penetration resistance competence, the competence was tested using herbs, woody plants, and tall trees. As a result, there was no tear of or damage to the waterproofing and root penetration resistance layer as well as the sweeping-down phenomenon of a waterproofing and root penetration resistance layer by soil. Also, the effect of the root growth of herbs, woody plants, and tall trees on the root penetration resistance system was confirmed.

• The Journal of the Korean dental association
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• v.14 no.9
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• pp.733-737
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• 1976

The result were obtained as follow : 1. Formocresol produced the widest zone of inhibition and camphorated parachlorophenol was the next and engenol was the narrowest. 2. Formocresol revealed the most efficted forming ability of the volatile gas and camphorated parachlorophenol was the next and eugenol was the least. 3. In comparing with the weight per ml. of the tested medicaments, eugenol was 1039.99mg/ml. 4. The amount of saturation in filter paper disc camphorated parachlorophenol showed the most and eugenol showed the least.

• The Journal of the Korean dental association
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• v.12 no.8
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• pp.613-617
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• 1974

The authors have studied the marginal leakage of various dental cements; Fynal cement (Caulk), Zinc cement (S.S. White) Carbo cement (Shofu, Poly-carboxylate cement), EBA cement (Opotow alumina cement), Propac (G-C's zinc oxide euginol cement), and Super cement (Shofu oxyphosphate zinc cement), by means of penetration of 2% methylene blue solution between orden crown restorations and human teeth in 150 cases. The result revealed as follow 1. None of the cements tested were free from dye penetration. 2. There was a wide difference in dye penetration among the trade brands of dental cement when immersed in dye solution before setting of cements. 3. EBA cement and Carbo cement showed comparatively low grade of dye penetration at the restorative margins.

• Journal of the Korean Data and Information Science Society
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• v.24 no.2
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• pp.401-408
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• 2013

Soil moisture is a very important variable in various area of hydrological processes. We predict the soil moisture using a support vector regression. The model is trained and tested using the soil moisture data observed in five sites in the Yongdam dam basin. With respect to soil moisture data of of four sites-Jucheon, Bugui, Sangieon and Ahncheon which are used to train the model, the correlation coefficient between the esimtates and the observed values is about 0.976. As the result of the application to Cheoncheon2 for validating the model, the correlation coefficient between the estimates and the observed values of soil moisture is about 0.835. We compare those results with those of artificial neural network models.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.727-732
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• 2000

Four 1/2-scale wall specimens with flange are tested. The purpose of this study is to investigate experimentally structural behavior of flanged walls in wall slab system apartment buildings considering effective width of flange wall. Main variables are the length of web wall and concrete strength. Cyclic lateral loads are applied at the top of the walls. A constant axial load of approximately $0.1f_{ck}\cdotA_g$ is maintained during the testing. Test result shows that the capacity of the wall was governed by aspect ratios rather than concrete strengths and that initial stiffness and strength of specimens is increased with increasing the stiffness of web wall.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.629-634
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• 2000

In this study, 9 reinforced concrete(RC) continuous beams were tested to investigate the arch action. By measuring longitudinal steel strains during the whole loading stages up to failure, the development of arch action is evaluated. Variables included are span length, longitudinal steel ratio and the presence of stirrups. As a result, it was known that measured steel tension in the span is substantially higher than the conventionally calculated values, and it was appeared that near the middle of the shear span the measured values exceeded the calculated values by factors of up to 1.4 or more.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.635-640
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• 2000

This paper describes an experimental investigation on the influence of concrete strength on tension stiffening behavior. Total 6 direct tension specimens were tested with variation of concrete strengths such as 260, 620, and 820kgf/$\textrm{cm}^2$. These test results were compared with tension stiffening models of CEB-FIP Model Code. It was appeared that, as concrete strength was increasing, CEB-FIP models estimated much more tension stiffening than these test results. As the result, it would be said that the influence of concrete strength on tension stiffening was not properly taken account for in CEB-FIP model.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.441-444
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• 2003

Polymer concrete has more useful than cement concrete in the strength and durability. So, it is widely utilizing as panel for wall, manhole for communication, foundation and underground connection box, etc. But polymer concrete is a defect that is disadvantageous in economical aspect because cost of resin is expensive. Polymer concrete (PC) using unsaturated polyester resins based on recycled polyethylene terephthalate(PET) plastic waste were used in our study for grasping its mechanical properties such as compressive strength, tensile strength, flexural strength and chemical resistance was tested by dealing with 20% HCl, 30% NaOH. As a result of it, compressive, tensile and flexural strength of PC indicated 752kgf/$\textrm{cm}^2$, 80kgf/$\textrm{cm}^2$ and 243kgf/$\textrm{cm}^2$ kind of satisfaction successively. Also, properties of chemical resistance are superior to those of cement concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.449-452
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• 2003

The objective of this study is to investigate the basic properties of polyester mortars using ground calcium carbonate(GCC), blast furance slag(BFS), fly ash(FA), ordinary portland cement(OPC) as fillers. Particle size distribution, particle shape and resin absorption of GCC, BFS, FA and OPC are checked. Polyester mortars with GCC, BFS, FA and OPC are prepared with various MEKPO content and tested for working life. The flexural and compressive strengths of the polyester mortars with MEKPO content of 0.5phr are evaluated. As a test result, the average sizes of GCC, BFS, FA and OPC are 9.7$\mu\textrm{m}$, 11.6$\mu\textrm{m}$, 21.2$\mu\textrm{m}$, 29.9$\mu\textrm{m}$. Resin absorption of FA is 1.5times larger than other fillers. The polyester mortar with FA at a MEKPO content of 0.5phr has the longest working life and the maximum flexural and compressive strengths.

• International Journal of Oral Biology
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• v.32 no.2
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• pp.45-49
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• 2007

In this study, the cytotoxicity of commonly used local anesthetics was evaluated on odontoblasts which are essential for pulpal homeostasis in vitro. Local anesthetics, such as articaine, bupivacaine, levobupivacaine, lidocaine, mepivacaine, prilocaine, and procaine, were tested on the odontoblast cell line, MDPC-23. The concentration-and time-dependent cytotoxic effects of local anesthetics on odontoblasts were measured by MTT assay. Among local anesthetics treated for 18 h, only bupivacaine significantly showed cell death in a concentration-($LC_{50}=1.2mM$) and time-dependent manner. To confirm cell death induced by bupivacaine, the observation of cell morphology and FACS using Annexin V and propidium iodide (PI) staining were performed. As a result of Annexin V and PI staining, as well as the morphological change, only bupivacaine induced apoptotic cell death on odontoblasts when compared with levobupivacaine and lidocaine. These results suggest that bupivacaine might affect normal pulpal integrity even after uneventful local anesthesia.