• Title/Summary/Keyword: Plate opening

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The Principles and Applications of Fluidized Bed Reactor with a Draft Tube (Draft Tube를 이용한 내부순환유동층 반응기의 원리와 응용)

  • 김상돈;송병호
    • Journal of Energy Engineering
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    • v.2 no.1
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    • pp.1-15
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    • 1993
  • 내부순환유동층이란 전형적인 기-고체 유동층 내부에 보조장치로서 원형관(draft tube) 또는 평판(partition plate)을 삽입하여 단일용기를 두 개의 층으로 분리하고 층 사이의 개방면적(opening area)을 통하여 입자의 순환이 일어나도록 하는 반응기 형태이다. (중략)

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Evaluation of Structural Capacity of SC Walls in Nuclear Power Plant accounting for the Area Lost to Openings (개구 저감률에 의한 원전 SC벽체의 내력 평가)

  • Chung, Chul-Hun;Jung, Raeyoung;Moon, Il Hwan;Lee, Jungwhee
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.6
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    • pp.2181-2193
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    • 2013
  • The shear wall with openings built with reinforced concrete(RC) have been elaborately studied by many researchers, whereas the steel plate concrete(SC) wall structure has not been investigated as much. Recent SC wall structures developed in Korea have been partly applied to nuclear power plant structures, although its design specification or guideline for the SC wall structure with openings has not been completed yet. This study based on the account for the area lost to openings evaluates the effects of opening on the structural capacity of the SC structure within nuclear power plant. The results obtained from the study on the area lost to openings have been compared with experimental and numerical studies.

THE CLINICAL STUDY OF MANDIBULAR FRACTURE

  • Lee, Dong-Keun;Yim, Chang-Joon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.11 no.1
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    • pp.69-77
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    • 1989
  • This is a retrospective study on 219 patients with mandibular fracture. The patients were treated in the Dept. of Oral Maxillofacial Surgery of WON KWANG UNIV. HOSPITAL from Aug. 1, 1984 to Sept. 30. 1988. The results were as follows. 1. The mandibular fractures occured most frequently in the twenties(35%) and male were predominant (74.7%) than females. 2. The most frequent etiologic factor was traffic accident(34.3%). 3. The most common location of fracture was symphysis(37.1%). And angle(27.6%), condyle(25.7%), ramus(1.6%) were next in order of frequency. 4. In mandible fracture, they have an average 1.8 fracture line. 5. The use of plate & screw system were more increased in the comparison of each year. 6. Intermaxillary fixation period was more reduced from the concept of 6 weeks fixation, due to the use of Plate & screw system. 7. Postoperative acute wound infection was developed 9.6% in 219 mandibular fracture patients. The compression osteosynthesis was most common cause of acute wound infection than any other treatment method. 8. Postoperative malocclusion was developed 4% in 219 mandibular fracture. And the compression osteosynthesis was most common cause of malocclusion. 9. Acute wound infection was detailed by the approach method. The Intraoral & extraoral combination method was most common cause on acute infection and intraoral, extraoral approach method was next in order of frequency. 10. Normal mouth opening process was proportioned to IMF period. The short IMF period have a fast normal mouth opening process.

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Microstructure and CTOD (crack tip opening displacement) of Deposit Weld Metal in 30 mm Thick Plate

  • Lee Hae-Woo;Kim Hyok-Ju;Park Jeong-Ung;Kang Chang-Yong;Sung Jang-Hyun
    • Korean Journal of Materials Research
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    • v.14 no.9
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    • pp.642-648
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    • 2004
  • The microstructure and crack tip opening displacement (CTOD) of deposit weld metal were investigated for a 30 mm- thick plate welded with flux cored arc welding (FCAW) and submerged arc welding (SAW) processes. The CTOD test was carried out both as welded condition and as stress-relieved specimen by local compression. The crack growth rates in FCAW were faster than those in a SAW, and the acicular ferrite content by the SAW process was increased relatively more than that by the FCAW process. The fatigue crack growth rate in a welded specimen was faster than that in locally compressed specimen. The CTOD value of locally compressed specimens was lower than that of as welded specimen. Furthermore, the CTOD value tested with the SAW process was higher than that tested with the FCAW process.

Utilizing CFRP and steel plates for repair of damaged RC beams with circular web openings

  • Fayyadh, Moatasem M.;Abed, Mohammed J.
    • Structural Engineering and Mechanics
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    • v.84 no.1
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    • pp.49-61
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    • 2022
  • This paper presents an experimental investigation into the effectiveness of using carbon fibre reinforced polymer (CFRP) and steel plates to repair damaged reinforced concrete (RC) beams with circular web openings at shear zones. It highlights the effectiveness of externally bonded CFRP and steel plates in repairing damaged RC beams by analysing the repaired beams'load capacity, deflection, strain, and failure mode. For the experiment, a total of five beams were used, with one solid beam as a control beam and the other four beams having an opening near the shear zone. Two beams with openings were repaired using inclined and vertical configuration CFRP plates, and the other two were repaired using inclined and vertical configuration steel plates. The results confirm the effectiveness of CFRP and steel plates for repairing damaged RC beams with circular openings. The CFRP and steel plates significantly increase ultimate capacity and reduce deflection under the openings. The inclined configuration of both CFRP and steel plates was more effective than the vertical configuration. Using an inclined configuration not only increases the ultimate capacity of the beams but also changes the mode of failure from shear to flexural.

Ultimate Strength Analysis of Stiffened Plate with Minor Collision Damage (작은 충돌손상을 가진 보강판의 최종강도 해석)

  • Lee, Tak-Kee;Rim, Chae-Whan
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.226-229
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    • 2006
  • The safety of on-going ships is one of important concerns in the view of environment and human life. The ship in bad condition is likely to be subjected to accidental loads such as collision. Once she has one or several minor collision damages in the form of circle or ellipse, her ultimate strength under compression or tension load will be reduced. Here, it is important to evaluate the reduction ratio of ultimate strength due to the damage from safety point of view. The problem of strength reduction of a plate with cutout such as opening hole has been treated by many researchers. As a result, a closed-form formula on the reduction of ultimate strength of a plate considering the effect of several forms of cutout was suggested. However, the structure of ships is composed of a plate and a stiffener so-called a stiffened plate, and it is likely to be damaged at a plate and stiffeners together in collision. This paper is to investigate the effect of minor collision damage on ultimate strength of a stiffened plate by using numerical analysis. For this study, the shape of minor collision damage of a stiffened plate was made by using contact algorithm. The deformed shape was used as an initial shape for ultimate stress analysis. Then, a series of nonlinear FE analysis was conducted to investigate the reduction effects of ultimate strength of the stiffened plate. The boundary condition was applied as simply supported at all boundaries, and the tripping of stiffener among failure mode under compression loading was neglected. These results were settled in the form of reduction ratio between ultimate of original intact stiffened plate and that of damaged stiffened plate.

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A Study on the Determination of Instantaneous Centre of Rotation and the Mandibular Movement (순간 회전 중심 결정과 하악골 운동에 관한 연구)

  • Kim, Cheong-Kyu;Kang, Dong-Wan;Chung, Chae-Heon
    • The Journal of Korean Academy of Prosthodontics
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    • v.26 no.1
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    • pp.63-84
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    • 1988
  • Recently the instantaneous centre concept has been used to understand the biomechanics by which a tissue derangement causes a mechanical derangement in temporomandibular joint. In this study, four male subjects without temporomandibular joint disorder and malocclusion were selected for the determination of the instantaneous centre of rotation (I.C.R) in the mandibular movement. The habitual opening and closing paths were recorded on the sagittal plate by two spring pencils attached on the lower anterior teeth which was designed for this study, and the I.C.R. was calculated by the computer program of Rouleaux's method. Also the computer graphic opening and closing movements of mandible were obtained according to the determined I.C.R. The results obtained from this study were as follows. 1. The instantaneous centres of rotation were not positioned within the condyle in the mandibular opening and closing movement. 2. There was some similarity between the anatomical curvature of the articular emience and the movement pattern of condyle. 3. The opening path and the closing path of the most superior pl)int of the condyle stowed a slight difference. 4. At the early stage of the habitual opening movement, the condyle was moved downward. 5. The opening and closing mandibular movements were simulated by the instantaneous centre of rotation which was determined by the computer program of Rouleaux's method.

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Case reports on neonatal mouth opening limitation due to congenital bilateral idiopathic hyperplasia of the coronoid processes (선천성 양측 특발성 오훼돌기 과형성으로 인한 개구장애의 증례보고)

  • Baek K.W.;Myung H.;Seo B.M.;Hwang S.J.;Lee J.H.;Choung P.H.;Kim M.J.;Choi J.Y.
    • Korean Journal of Cleft Lip And Palate
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    • v.7 no.2
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    • pp.133-139
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    • 2004
  • Congenital bilateral idiopathic hyperplasia of the coronoid processes presents with limited mouth-opening without visible maxillofacial deformity or temporomandibular joint dysfunction / disorder. According to Blanchard et al and McLoughlin et al, it was lnitially described in 1853 by Langenbeck, and the first cases were reported by Holmes in 1956. Since then, there have been regular reports of a certain number of cases. In 1995, McLoughlin et al recorded 79 published cases of bilateral hyperplasia of the coronoid processes. Among them, Fabie et al have found only 3 published cases relating to children younger than 8 years, and have presented the first case of objectively diagnosed restricted mouth opening from birth by pediatricians. Authors have experienced 2 child patients with mouth opening limitation who was diagnosed congenital bilateral idiopathic hyperplasia of the coronoid processes without any other TNJ morphology in Dept of Oral and Maxillofacial surgery, Seoul National University Dental Hospital in 2004. Coronoidectomy was performed and postoperative active mouth opening exercise is indicated. Authors report 2 cases of congenital bilateial idiopathic hypeiplasia of the coronoid processes with literature liview.

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THE EFFECT OF EARLY REMOVAL OF THE FIXATION PLATES AND ACTIVE MOUTH OPENING EXERCISE ON THE TEMPOROMANDIBULAR DYSFUNCTION AFTER MANDIBULAR SETBACK SURGERY (하악골 전돌증 환자에서 하악지 시상분할골절단술후 금속고정판의 조기제거 및 기능운동이 턱관절장애에 미치는 영향)

  • Jeon, Joon-Hyuk;Kim, Yeo-Gab;Ryu, Dong-Mok;Lee, Baek-Soo;Oh, Jung-Hwan;Kwon, Yong-Dae;Yoon, Byung-Wook
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.27 no.6
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    • pp.545-551
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    • 2005
  • Purpose: The effect of orthognathic surgery on the temporomandibular dysfunction has been controversial. The purpose of this study is to prove statistically that early removal of fixation plate at postoperative 2 weeks with active exercise of mouth opening could relieve preoperative temporomandibular dysfunction and reposition of temporomandibular joint. Patients and Methods: All 28 subject patients underwent mandibular setback with BSSRO in Kyunghee medical center by one surgeon. The fixation plates used for rigid fixation were removed at postoperative 2 weeks and we had the patients excercise active mouth opening with intermaxillary rubber rings for the guiding proper postoperative occlusion. Temporomandibular symptoms were checked and radiographs were taken before surgery, within a month after surgery, six to twelve months after surgery respectively. Results: The temporomandibular dysfunction symptoms were relieved after the surgery and the condyle was displaced inferior-posteriorly immediate after surgery and repositioned toward its original position during follow-up periods. Conculusion: Orthognathic surgery may benefit temporomandibular joint dysfunction by obtaining a postoperative stable occlusion and more physiologic neuromuscular function. The early removal of fixation plates after BSSRO could reposition the temporomandibular joint to physiologic position and relieve the symptoms of temporomandibular dysfunction by permitting movement of proximal segment.