• Title/Summary/Keyword: Field wall

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Usefulness of a Transconjunctival Approach in the Reconstruction of the Medial Blow-Out Wall Fracture

  • Lee, Chi An;Sun, Hook;Yun, Ji Young
    • Archives of Craniofacial Surgery
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    • v.18 no.2
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    • pp.76-81
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    • 2017
  • Background: A transcaruncular approach is typically used for reconstructions of medial wall fractures. However, others reported that a transconjunctival approach was conducive for securing an adequate surgical field of view. In this study, we aimed to examine the extent of repair of medial wall fracture via a transconjunctival approach. Methods: We retrospectively reviewed the medical records of 50 patients diagnosed as having medial wall fracture via preoperative computed tomography and who underwent surgery between March 2011 and February 2014. The fracture location was defined by dividing each of the anterior-posterior and superior-inferior distances into three compartments. Results: A transcaruncular approach was used in 7 patients, while the transconjunctival approach was performed in the remaining 43 patients. The transconjunctival approach enabled a relatively broad range of repair that partially included the front and back of the medial wall, and was successful in 86% of the entire study population. Conclusion: It is known that more than 50% of total cases of the medial wall fracture occur mainly in the middle-middle portion, a majority of which can be reconstructed via a transconjunctival approach. We used a transconjunctival approach in identifying the location of the fracture on image scans except for cases including the fracture of the superior portion in patients with medial wall fracture. If it is possible to identify the location of the fracture, a transconjunctival approach would be an useful method for the reconstruction in that it causes no damages to the lacrimal system and is useful in confirming the overall status of the floor.

A case Study on Collapse Causes and Restoration of Retaining Wall with Vegetated Concrete Block (식생블록 옹벽의 붕괴원인 및 복구방안에 관한 사례 연구)

  • Hong, Gigwon;You, Seung-Kyong;Yun, Jung-Mann;Park, Jong-Beom;Lee, Kwang-Wu
    • Journal of the Korean Geosynthetics Society
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    • v.15 no.4
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    • pp.105-115
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    • 2016
  • This paper describes a restoration of retaining wall, which was collapsed by rainfall. The failure causes was analyzed by field case, and then the countermeasure was suggested. The failure causes confirmed that observance of design and construction criteria was insufficient. It also was the climate condition like a rainfall and inappropriate construction management. The stability analysis for retaining wall, soil improvement and reinforced earth wall was conducted to confirm validity of the countermeasure. The analysis results showed that the suggested construction method satisfied in required safety factors. Therefore, it should be secured the stability of the structure based on the application of appropriate design method and construction management, when structure was constructed.

Analysis on Failure Causes and Stability of Reinforced Earth Wall Based on a Field Case (현장사례를 이용한 보강토옹벽의 파괴원인 및 안정성 분석)

  • Hong, Kikwon;Han, Jung-Geun;Lee, Jong-Young;Park, Jai-Seok
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.1
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    • pp.109-114
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    • 2013
  • This paper describes the global stability of the reinforced earth wall, which was collapsed by heavy rainfall. The seepage analysis was conducted to confirm the change effect of groundwater level on slope with reinforced earth wall. The seepage analysis result confirmed that the change of groundwater level is greatly influenced by rainfall. According to the change of groundwater level, the global stability analysis with reinforced earth wall was conducted based on the results of seepage analysis. The safety factor of the slope was 0.476 when the wall is collapsed firstly. The collapse cause analyzed that soil strength was weaken because the ground was saturated by continuous rainfall. Therefore, the global stability, which is considered heavy rainfall, should be conducted at design and construction of reinforced earth wall.

A REVIEW OF CANDU FEEDER WALL THINNING

  • Chung, Han-Sub
    • Nuclear Engineering and Technology
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    • v.42 no.5
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    • pp.568-575
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    • 2010
  • Flow Accelerated Corrosion is an active degradation mechanism of CANDU feeder. The tight bend downstream to Gray loc weld connection, close to reactor face, suffers significant wall thinning by FAC. Extensive in-service inspection of feeder wall thinning is very difficult because of the intense radiation field, complex geometry, and space restrictions. Development of a knowledge-based inspection program is important in order to guarantee that adequate wall thickness is maintained throughout the whole life of feeder. Research results and plant experiences are reviewed, and the plant inspection databases from Wolsong Units One to Four are analyzed in order to support developing such a knowledge-based inspection program. The initial thickness before wall thinning is highly non-uniform because of bending during manufacturing stage, and the thinning rate is non-uniform because of the mass transfer coefficient distributed non-uniformly depending on local hydraulics. It is obvious that the knowledge-based feeder inspection program should focus on both fastest thinning locations and thinnest locations. The feeder wall thinning rate is found to be correlated proportionately with QV of each channel. A statistical model is proposed to assess the remaining life of each feeder using the QV correlation and the measured thicknesses. W-1 feeder suffered significant thinning so that the shortest remaining life barely exceeded one year at the end of operation before replacement. W-2 feeder showed far slower thinning than W-1 feeder despite the faster coolant flow. It is believed that slower thinning in W-2 is because of higher chromium content in the carbon steel feeder material. The average Cr content of W-2 feeder is 0.051%, while that value is 0.02% for W-1 feeder. It is to be noted that FAC is reduced substantially even though the Cr content of W-2 feeder is still very low.

Material Analysis and Provenance Interpretation for Rock Properties of the Gwangjueupseong (Gwangju Town Wall), Korea (광주읍성 축성암석의 재질분석과 산지해석)

  • Lee, Myeong-Seong;Chun, Yu-Gun;Seo, Jeong-Seog;Lee, Chan-Hee
    • Journal of Conservation Science
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    • v.25 no.1
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    • pp.61-76
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    • 2009
  • Gwangjueupseong (Gwangju Town Wall) has been found in the site of the Asian Culture Complex (former Provincial Government of Jeonnam) by archaeological field survey. The length of the remaining wall is 85.1m, and the Town Wall consists of ten kinds of rock type. The major rock types are dacite (41.1%) and andesite (35.7%). Dacite composes main rock blocks of the wall, and andesite is used to fill the cavity between main rock blocks. These rocks look very similar to basement rocks of the Mudeung Mountain on the basis of occurrence features, magnetic susceptibility, petrological, mineralogical and geochemical properties. Also, quarrying traces were found on the southwestern slope of the mountain along the Jeungsimsa Temple valley. Thus, it is probable that the rock materials of the Gwangju Town Wall were supplied from the Mudeung Mountain and that they were transported along the Gwangju river.

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Lateral Resistance of Reinforced Light-Frame Wood Shear Walls

  • Hyung Woo LEE;Sang Sik JANG
    • Journal of the Korean Wood Science and Technology
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    • v.51 no.1
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    • pp.58-66
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    • 2023
  • In light-frame timber construction, the shear wall is one of the most important components that provide resistance to lateral loads such as earthquakes or winds. According to KDS (Korea Design Standard) 42 50 10, shear walls are to be constructed using wood-based structural sheathing, with studs connected by 8d nails spaced 150 mm along the edge and 300 mm in the field. Even though small-scale residential timber building can be designed to exhibit seismic resistance using light-frame timber shear walls in accordance with KDS 42 50 10, only the abovementioned standard type of timber shear wall is available. Therefore, more types of timber shear walls composed of various materials should be tested to measure their seismic resistance, and the results should be incorporated into the future revision of KDS 42 50 10. In this study, the seismic resistance of shear walls composed of structural timber studs and wood-based structural sheathing with reinforced nailing is tested to evaluate the effects of the reinforcement. For the nailing reinforcement, shear wall specimens are constructed by applying nail spacings of 75-150 mm and 50-100 mm. For the shear wall specimens with one sheathing and reinforced nailing, the shear strengths are 1.7-2.0 times higher than that of the standard shear wall (nail spacing of 150-300 mm). The shear strength of the shear walls with sheathing on both sides is 2.0-2.7 times higher than that of the standard shear wall.

Analysis of Monitoring Results and Back Analysis for Rigid Diaphragm Wall Supported by Ground Anchor (지반앵커로 지지된 강성 지하연속벽체의 상세계측 결과분석 및 역해석 평가)

  • Lee, Jong-Sung;Hwang, Eui-Suk;Cho, Sung-Hwan;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.25 no.5
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    • pp.39-46
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    • 2009
  • In this study, behavior of a rigid continuous wall, earth pressure distribution with construction stage, and axial force of earth anchors were evaluated based on field monitoring data and numerical analysis results. For this purpose, a construction site excavated using the diaphragm wall was selected and full instrumentation system was introduced. From monitoring results, it was found that the values of horizontal displacement of the wall measured from the inclinometers, which were installed within the diaphragm wall were similar to analytical value. The earth pressure increased with excavation progress due to jacking force of the ground anchors installed in previous excavation stages. When the excavation depth reached 60% of the final depth, observed earth pressure distribution was similar to that estimated from Peck's apparent earth pressure distribution. When the excavation depth was around 90% of the final depth, values of observed earth pressure showed middle values between those of Peck's and Tschebotarioffs apparent earth pressures. It was also observed that, when excavation depth is deep, values of the earth pressures from the rigid wall were similar to those estimated from conventional earth pressure distribution shape proposed for flexible walls.

Model Test for the Behavior of Retaining Walls Under Surcharge Load (상재하중을 받는 토류벽체의 거동에 관한 모형실험 연구)

  • Jung, On-Su;Huh, Kyung-Han
    • Journal of the Korean Society of Hazard Mitigation
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    • v.5 no.4 s.19
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    • pp.49-57
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    • 2005
  • The purpose of this study is to closely examine the influence of the surcharge load applied to the retaining wall through some model tests, in which wall stiffness in each stage of excavation, horizontal displacement of the retaining wall and surface displacement of the backfill according to wall stiffness and ground conditions, and change and distribution of the earth pressure applied to it were measured and their values were produced, then these values were mutually compared with their theoretical values and their values after analysis of the data obtained at the field, and they were analytically studied, in order to closely examine the influence of the surcharge load applied to the retaining wall. Findings from this study are as follows: The shape of ground surface settlement curve on the model ground under surcharge load, different from the distribution curve of regular probabilities which is of a shape of ground surface settlement under no surcharge load, appears in that settlement in an arching shape shows where the center part of surcharge load shows the maximum settlement. In examining the maximum horizontal displacement with the surcharge load applied to each stage of excavation, it occured at the point of 0.8H(excavation depth) when finally excavated. Regarding the range in which the displacement of the retaining wall increases according to application of surcharge load, the increment of displacement showed till the point of depth which is of two times of the distance of load from the upper part of the wall. Also since each displacement of the foundation plate caused by the ground surface settlement according to each stage of excavation occured most significantly at the final stage. Also since regarding wall stiffness, the wall of its thickness of 4mm(flexible coefficient $p:480m^3/t$), produced maximum 3 times of wall stiffness than its thickness of 9mm(flexible coefficient $p: 40m^3/t$), it was found out that influence of wall stiffness is so significant.

Variation of the Switching Field of Composite Nanowires with Different Widths

  • Kim, Seung-Ho;Lee, Han-Seok;Lee, Seung-Hyun;Lee, Woo-Young;Lee, J.
    • Journal of Magnetics
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    • v.13 no.4
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    • pp.167-169
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    • 2008
  • The switching field of a 300 nm wide nanowire has been controlled by attaching a wide wire to it. The width of the wide wires varies from 700 nm to 2000 nm. While the connection of the two wires does not affect the switching field of the wide wires, it strongly affects the 300 nm-wire, resulting in a decrease of the switching field of the isolated wire from 175 Oe to 54 Oe when the 2000 nm-wire is connected to it. This result clearly shows that the switching field of the nanowire can be engineered by attaching a nucleation pad that has a different magnetic anisotropy.

Estimated Risk of Radiation Induced Contra Lateral Breast Cancer Following Chest Wall Irradiation by Conformal Wedge Field and Forward Intensity Modulated Radiotherapy Technique for Post-Mastectomy Breast Cancer Patients

  • Athiyaman, Hemalatha;M, Athiyaman;Chougule, Arun;Kumar, HS
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.12
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    • pp.5107-5111
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    • 2016
  • Background: Epidemiological studies have indicated an increasing incidence of radiation induced secondary cancer (SC) in breast cancer patients after radiotherapy (RT), most commonly in the contra-lateral breast (CLB). The present study was conducted to estimate the SC risk in the CLB following 3D conformal radiotherapy techniques (3DCRT) including wedge field and forward intensity modulated radiotherapy (fIMRT) based on the organ equivalent dose (OED). Material and Methods: RT plans treating the chest wall with conformal wedge field and fIMRT plans were created for 30 breast cancer patients. The risks of radiation induced cancer were estimated for the CLB using dose-response models: a linear model, a linear-plateau model and a bell-shaped model with full dose response accounting for fractionated RT on the basis of OED. Results: The plans were found to be ranked quite differently according to the choice of model; calculations based on a linear dose response model fIMRT predict statistically significant lower risk compared to the enhanced dynamic wedge (EDW) technique (p-0.0089) and a non-significant difference between fIMRT and physical wedge (PW) techniques (p-0.054). The widely used plateau dose response model based estimation showed significantly lower SC risk associated with fIMRT technique compared to both wedge field techniques (fIMRT vs EDW p-0.013, fIMRT vs PW p-0.04). The full dose response model showed a non-significant difference between all three techniques in the view of second CLB cancer. Finally the bell shaped model predicted interestingly that PW is associated with significantly higher risk compared to both fIMRT and EDW techniques (fIMRT vs PW p-0.0003, EDW vs PW p-0.0032). Conclusion: In conclusion, the SC risk estimations of the CLB revealed that there is a clear relation between risk associated with wedge field and fIMRT technique depending on the choice of model selected for risk comparison.