• Title/Summary/Keyword: 쐐기구조

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Diagnostic Radiology and Conservative Management of L1 Lumbar Spine with Compression Fracture (L1 요추 압박골절에 대한 진단방사선학 및 보존적 치료)

  • 김재웅
    • The Korean Journal of Food And Nutrition
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    • v.11 no.2
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    • pp.165-170
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    • 1998
  • Diagnostic radiology and conservative management for S75 patient with L1 lumbar fracture by traffic accidents were discussed with references, and then the obtained results were as follows ; 1. Wedging compression fractures with 10% deformity was confirmed at anterior vertebral body of L1 lumbar spine through lateral plain X-ray film. 2. Irregular bony fractures were observed at anterior vertebral body of L1 lumbar spine by CT scans, anatomically T12-L1 sites showed highly frequency of injuries, Denis's fracture type was classified as multiple compression fracture at anterior column without abnormal middle and posterior column, also no Cobb's angle, and then Frankel's neurological classification was E grade. 3. Orthopaedic treatments were performed with conservative methods. With rest on the bed, anti-in-flammatory medication, electrolyte and nutritional solution, the pain diminished. 4. After 3 weeks, rehabilitation was worked with putting on polyethylene back corset, although pains remained slightly until after 8 weeks, thereafter the spine showed gradually stability.

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Spermatogenesis of Coreoperca herzi (Perciformes; Percichthyidae) (꺽지(Coreoperca herzi)의 정자형성)

  • Gye, Myung-Chan
    • Korean Journal of Ecology and Environment
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    • v.35 no.3 s.99
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    • pp.232-236
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    • 2002
  • In an effort to uncover the reproduction of Korean brook perch Coreoperca herzi testis anatomy and sperm morphology were studied. Fish samples were collected in the Sooypcheon river from May to October 2001. White-colored testes have wedgeshaped external morphology, and developed symmetrically in the dorsal cavity of the trunk. Isogenetic germ cells developed in the cyst located in seminiferous lobule. Each lobule showed significant asynchrony in the spermatogenic stage of the cyst. Sperm was 43 ${\mu}$m in length. The round head was 2.2 ${\mu}$m long. The middle piece developed beneath the head was 0.5 ${\mu}$m long. Tail was 40 ${\mu}$m in length. Coomassie brilliant blue (CBB) gave rise the intense staining in the apex of sperm head and middle piece, suggesting the possible development of acrosome.

A Study on the Physical Behavior and the Applicability of Rock Anchorage System of a Suspension Bridge in Domestic Island (현수교 지중정착식 앵커리지의 거동특성과 국내 도서지역에서의 적용성에 대한 연구)

  • Yang, Euikyu;Choi, Youngseok;Choi, Kyungseob;Kim, Daehak;Jeon, Yongjun
    • Journal of the Korean Geotechnical Society
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    • v.37 no.2
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    • pp.33-48
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    • 2021
  • The rock anchorage of a suspension bridge is an outstanding anchorage type from environmental and economical perspective, although it should be applied when the bearing foundation is fresh enough to resist large cable loads. In practice, geotechnical engineers have encountered difficulties in designing the anchorage structure due to the fact that the physical behaviors of rocks against cable loads have not yet been fully proved and its design method was not established yet. In this study, model tests and numerical studies were performed to evaluate the behavior of the rock anchorage system planned under hard rock layers in domestic islands, and results suggest that the shape of asymmetric rock wedges can resist the tension loads with self weight and shear resistance. Additionally, real scale trial tests were carried out to verify the accuracy of an inclined drilling penetrating hard rock layers to install tendon to the bearing plate.

Analysis of Shear Behavior of Reinforced ALWAC Beam Using Interface Elements (계면요소를 이용한 경량철근콘크리트 보의 전단거동해석)

  • Rhee, Inkyu;Kim, Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1A
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    • pp.107-115
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    • 2006
  • A challenging topic was and still is the failure behavior of concrete beams without shear reinforcement. In spite of substantial experimental and theoretical efforts in the past, the mechanism of shear failure is not entirely understood. ALWAC is of importance to the current construction industry. Most of present concrete research focuses on high performance concrete, by which in meant a cost effective material that satisfies demanding performance requirements, including durability. The advantages of ALWAC are its reduced mass and improved thermal and acoustic insulation properties, while maintaining adequate strength. In spite of these advantages, its ultimate failure behavior has not been well defined for adequate design process. This paper will investigate mainly the shear behavior of reinforced ALWAC beam without web reinforcements numerically with experimental evidences.

Evaluation of Characteristics of Ground Anchor Using Large Scale Laboratory Test (실규모 실험을 이용한 그라운드 앵커의 거동 특성 평가)

  • Sangrae Lee;Seunghwan Seol
    • Journal of the Korean GEO-environmental Society
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    • v.24 no.11
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    • pp.19-24
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    • 2023
  • Ground anchor has been widely used specially for maintaining stability on reinforced cut slope in expressway. While the durability of the ground anchors should be ensured over the service life. However, the long-term loss of tensile force has occurred in most of field-installed anchors. Main causes are not clearly identified and very few studies have been made for analyzing long-term behavior of ground anchor in slopes. In this study, full-scale model tests and long-term measurements were made to obtain the load-displacement data and identified the causes of the long-term behaviors of ground anchor. As a result, the bond strength decreases exponentially with increasing water-binder ratio. Especially, groundwater is the most influencing factor to the bond strength. In the long-term behavior, the load decreases sharply until the initial settlement stabilized, and thereafter the tension force decreases constantly.

Sediments and Design Considerations in the Forebay of Stormwater Wetland (강우유출수 처리목적 인공습지 침강지의 퇴적물 특성 및 설계 적정성에 관한연구)

  • Park, Kisoo;Cheng, Jing;Kim, Youngchul
    • Journal of Wetlands Research
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    • v.14 no.2
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    • pp.223-235
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    • 2012
  • In this paper, field study results about accumulation of sediments and its property in the forebay of wetland aiming at stormwater from rural area wherein intensive cow feeding lots are operated are provided. In addition, some design aspects are discussed. Amount of sediment generation in the longitudinal direction of forebay was found to be affected by hydrological factors such as rainfall depth and intensity. Nutrient contents in the sediments of this wetland were 10 times higher than those in stormwater wetland in rural area without animal-feeding lot. Total-Pb and As contents show similar level to values from the soils of surrounding watershed, but Total-Cu content was higher due to the animal feeding lots. Yearly amount of sediment generation, its depth and volume were estimated to 13tons, 23cm, and $65m^3$. Based on these results and recommended guideline by Korean Ministry of Environment, dredging frequency was found to be about 2.7years. The shape of forebay has to be carefully designed to deal with a great change in flow rate. According to the results of sediment depth analysis, instead of the present rectangular, wedge-shape forebay is more desirable in handling scouring caused by high flows.

Brillouin Light Scattering Study of Magnetic Anisotropy in GaAs/Fe/Au System (Brillouin Light Scattering을 이용한 GaAs/Fe/Au 구조의 자기이방성)

  • Ha, Seung-Seok;You, Chun-Yeol;Lee, Suk-Mock;Ohta, Kenta;Nozaki, Takayuk;Suzuki, Yoshishige;Roy, W. Van
    • Journal of the Korean Magnetics Society
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    • v.18 no.4
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    • pp.147-153
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    • 2008
  • It has been well-known that the Fe/GaAs heterostructure has a small lattice mismatch of 1.4% between Fe and GaAs, and the Fe layer is grown epitaxially on the the GaAs substrate. There are rich physics are observed in the GaAs/Fe interface, and the spininjection is actively studied due to its potential applications for spintronics devices. We fabricated Fe wedge layer in the thickness range $0{\sim}3.4$ nm on the GaAs(100) surface with 5-nm thick Au capping layer. The magnetic anisotropy of the Fe/GaAs system was investigated by employing Brillouin light scattering(BLS) measurements in this study. The spin wave excitation of Fe layer was studied as the function of intensity and the in-plane angle of external magnetic field, and thickness of Fe layer. Also these various dependences were analyzed with analytic expression of spin wave surface mode in order to determine the magnetic anisotropies. It has been found that the GaAs/Fe/Au system has additional uniaxial magnetic anisotropy, while the bulk Fe has biaxial anisotropy. The uniaxial anisotropy shows increasing dependency respected to decreasing thickness of Fe layer while biaxial anisotropy is reduced with Fe film thickness. This result allows the analysis that the uniaxial anisotropy is originated from interface between GaAs surface and Fe layer.

3-D Numerical Analysis for the Verification of Bearing Mechanism and Bearing Capacity Enhancement Effect on the Base Expansion Micropile (선단 확장형 마이크로파일의 3차원 수치해석을 통한 지지 메커니즘 및 지지력 증대효과 검증)

  • Lee, Seokhyung;Han, Jin-Tae;Jin, Hyun-Sik;Kim, Seok-Jung
    • Journal of the Korean Geotechnical Society
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    • v.37 no.2
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    • pp.19-31
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    • 2021
  • Micropiles are cast-in-place piles with small diameters. The advantage of micropile is low construction expense and simple procedures, so it is widely applied to existing buildings and structures for the reinforcement of foundation and seismic performances. The base expansion structure has been developed following the original mechanism of horizontal expansion steps under compressive loading. This kind of structure can be installed at the pile end to improve the bearing capacity by tip area enlargement and horizontal force increment to the pile surface area. However, 'Micropile with base expansion structure' cannot be put into practical use, because detailed verification for the developed technique has not been conducted so far. In this research, 3-D numerical analysis was conducted to figure out the bearing mechanism of base expansion micropile and to verify the bearing capacity improvement compared to the general micropiles. 3-D modelling of micropile with base expansion structure was carried out and input parameter was determined. Bearing mechanism induced by base expansion structure was analyzed by lab-scale modelling, and bearing capacity improvement was verified by field-scale analysis.

Deformation structures of the Jurassic Ogcheon granite and the Honam Shearing, Ogcheon Area, Korea (옥천지역 쥬라기 옥천화강암의 변형구조와 호남전단운동)

  • Kang, Ji-Hoon
    • The Journal of the Petrological Society of Korea
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    • v.19 no.1
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    • pp.19-30
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    • 2010
  • The Jurassic Daebo Ogcheon granite is distributed in the Ogcheon area which is located in the central part of the Ogcheon Belt, Korea. This paper newly examines the timing of Honam shearing on the basis of the petrofabric researches on the deformation structures of the Ogcheon granite. The structural shape of Ogcheon granite is mainly characterized by a wedge shaped of E-W trend and an elongate shape of ENE trend in geological map and by contacts parallel to the regional S1 foliation in the host Ogcheon supergroup. It indicates that the pluton was permittedly emplaced after the S1 formation. The main deformation structures are marked by a solid-state tectonic foliation of N-S trend, which passes through the contact of the pluton, and by an aplitic dyke of E-W trend, and by sinistral, NW and E-W oriented shear zones on the eastern border of the pluton. The petrofabric study on the main deformation structures suggests that the tectonic foliation and the aplitic dyke were formed by the Honam dextral strike-slip shearing of (N)NE trend at ca. $500{\sim}450^{\circ}C$ deformation temperature, and that the sinistral shear zones could be induced by the dextral rotation of the pluton from its original site of intrusion, that is, by the shear strain which is due to sliding of the pluton past the host rocks. The history of emplacement and deformation of the Ogcheon granite and the previous results on the timing of Honam shearing would be newly established and reviewed as follows. (1) Early~Middle Jurassic(187~170 Ma); intrusion of syntectonic foliated granite related to Early Honam shearing, (2) Middle Jurassic(175~166 Ma); main magmatic period of Jurassic granitoids, the permitted emplacement of the Ogcheon granite, (3) Middle~Late Jurassic(168~152 Ma); main cooling period of Jurassic granitoids, the deformation of the Ogcheon granite related to Late Honam shearing. Thus, this study proposes that the Honam shear movement would occur two times at least during 187~152 Ma (ca. 35 Ma) through the intertectonic phase of 175~166 Ma.

Behavior Interpretation and Secondary Degradation of the Standing Sculptured Buddha at the Yongamsa Temple, Ogcheon, Korea (옥천 용암사 마애불의 거동특성 해석과 이차적 훼손)

  • Lee, Chan Hee;Chung, Youn Sam;Kim, Ji Young;Yi, Jeong Eun
    • Journal of Conservation Science
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    • v.17 s.17
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    • pp.83-94
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    • 2005
  • Host rock or the standing sculptured Buddha in the Yongamsa temple is macular porphyritic biotite granite, which has gone through mechanical and chemical weathering. The rock around the Buddha statue is busily scattered with steep inclinations that are almost vertically discontinuous planes with the strikes of $N8^{\circ}E$. Especially the development of the joints that cross the major joints causes the structural instability of the rock. The rock of the Buddha statue is separated into several rock blocks because of many different discontinuity. Thus it is estimated that the bed rock has not only plane and toppling failure but also wedge failure in all the sides. Since the differential pressure is imposed on the body of the Buddha in the host rock, it is urgent to give a reinforce treatment of geotechnical engineering for the safe of its structural stability. Very contact area of joints have turned into soil, which promotes the growth of weeds and plant roots, then aggravates the mechanical weathering of the rock. Thus conservational treatments should also be considered to get rid of secondary contaminants and vegetation along the discontinuities and to prevent further damages.

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