• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.18-25
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• 2005

Traumatic bone cyst is a nonodontogenic cyst without epithelial-linig which contains fluid in it's cavity, and it is limited by bone walls with no evidence of infection. Traumatic bone cyst is asymptomatic and appears more frequently in the second decade. Gender distribution is approximately equal, although males are affected slightly often than females. Radiographically the lesion shows a well demarcated radiolucent lesion of variable size and the lesion may have scalloped margins. The adjacent teeth to traumatic bone cyst remains vital. Traumatic bone cyst is usually treated by surgical exploration and currettage of the lesion. In the first case of this case report, the patient was refered from the local dental clinic for the radiolucent area under the left mandibular first molar. From the panorama radiograph at the first visit, the radiolucent area of the left mandible showed a well defined scalloped margin and identified as traumatic bone cyst. In the second case, the patient have visited for the chief complaint of swelling and abcess of right maxillary second premolar. In the radiographic check up with panorama radiograph, the radiolucent lesion with well demarcated scalloped margin was found in the right mandible body, and identified as traumatic bone cyst. In the first case, overinstrumentation was done through the mesial root canal to irrigate the lesion. In the second case, not any treatment was done, and watched the progression of the lesion. And in both cases, after two month, the radiolucency and the size of the lesion has decreased to show healing in progress.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.09a
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• pp.21-36
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• 2005

Although the main geology of Korea consists of granite and gneiss, it Is not uncommon to encounter anisotropy Phenomena in crosshole radar tomography even when the basement is crystalline rock. To solve the anisotropy Problem, we have developed and continuously upgraded an anisotropic inversion algorithm assuming a heterogeneous elliptic anisotropy to reconstruct three kinds of tomograms: tomograms of maximum and minimum velocities, and of the direction of the symmetry axis. In this paper, we discuss the developed algorithm and introduce some case histories on the application of anisotropic radar tomography in Korea. The first two case histories were conducted for the construction of infrastructure, and their main objective was to locate cavities in limestone. The last two were performed In a granite and gneiss area. The anisotropy in the granite area was caused by fine fissures aligned in the same direction, while that in the gneiss and limestone area by the alignment of the constituent minerals. Through these case histories we showed that the anisotropic characteristic itself gives us additional important information for understanding the internal status of basement rock. In particular, the anisotropy ratio defined by the normalized difference between maximum and minimum velocities as well as the direction of maximum velocity are helpful to interpret the borehole radar tomogram.

• Economic and Environmental Geology
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• v.47 no.2
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• pp.181-191
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• 2014

Olon Ovoot gold mine, Mongolia, is located in the Omnogobi province which is south 500 km from Ulaanbaatar. The mine area consists of the Devonian Bot-Uul khudag formation, the Upper Devonian intrusions, and the Upper Devonian or the Early Jurassic quartz veins. The quartz veins contain from 1 to 32 g/t gold with an average of 5 g/t gold. The quartz veins vary from 0.2 m to 25 m and are concordant or discordant with foliation of the green-schist. The mineralogy of the quartz veins is simple and consists of mainly of white massive quartz with partly transparent quartz in cavity. Quartz, sericite, chlorite, pyrite and carbonates(ankerite, dolomite and siderite) were observed in the alteration zone. Carbonate minerals occur as disseminated, coarse or fine grains with quartz, sericite, chlorite and pyrite near vein margin or within wall-rock xenoliths in quartz vein. Ankerite is present as later dark grey ankerite(13.51 to 16.89 wt.% FeO) and early white grey ankerite(16.67 to 19.90 wt.% FeO). The FeO contents of early ankerite are higher than those of later ankerite. Dolomite contains from 3.89 to 10.44 wt.% FeO and from 0.10 to 0.47 wt.% MnO. Dolomite is present as dark grey dolomite(4.06 to 6.87 wt.% FeO), light white grey dolomite(6.74 to 7.58 wt.% FeO) and grey white dolomite(7.33 to 10.44 wt.% FeO). The FeO contents of white grey dolomite are higher than those of dark grey dolomite. Siderite contains from 34.25 to 48.66 wt.% FeO, from 6.79 to 14.38 wt.% MgO, from 0.06 to 0.26 wt.% MnO and from 2.08 to 8.08 wt.% CaO.