• 제목/요약/키워드: Cavity Wall

검색결과 546건 처리시간 0.022초

습공기 유동에서 발생하는 충격파와 경계층 간섭의 피동제어에 관한 연구 (Study on the Passive Shock/Boundary Layer Interaction Control in Transonic Moist Air Flow)

  • 백승철;권순범;김희동
    • 한국항공우주학회지
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    • 제30권8호
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    • pp.21-29
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    • 2002
  • 본 연구는 다공벽과 공동을 사용한 피동제어법을 천음속 습공기 유동에서 발생하는 충격파와 경계층 간섭에 적응하였다. 지배방정식은 액적성장 방정식과 완전히 결합된 2차원, 비정상, 압축성 Navier-Stokes 방정식이며, 3차 오더 MUSCL 타입의 TVD 기법을 사용하였다. 또 난류모델로는 Baldwin-Lomax 모델을 적용하였다. 본 연구에서 적용한 제어법의 유용성을 조사하기 위해 유동의 전압손실과 충격파 변위의 시간의존성 거동을 해석하였다. 수치계산 결과로부터 본 연구의 피동제어기법을 통해 천음속 습공기 유동에서 발생하는 충격파/경계층 간섭으로 인한 전압손실이 상당히 감소하였고, 익에서 충격파 운동을 억제하는 것으로 나타났다. 또 다공영역의 위치가 본 연구의 제어법의 효과에 상당한 영향을 준다는 것이 발견하였다.

광투시 진입기구를 이용한 너스 수술 (Nuss Procedures using a Transilluminated Introducer)

  • 이승진;백강석;전철우;이석열;이철세
    • Journal of Chest Surgery
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    • 제41권6호
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    • pp.803-806
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    • 2008
  • 너스 수술은 미용적으로 우수한 수술법이나 전종격동 박리 시 출혈과 장기 손상을 유발할 수 있다. 저자들은 기존의 전종격동 통과방법이 갖고 있는 단점을 극복하기 위해 노력해 왔고, 보다 안전하고 간편하게 양측에 1cm의 수술 창으로 수술을 진행 할 수 있는 광투시 진입기구를 개발하게 되었다. 총 67명의 환자가 광투시 진입기구를 이용한 너스 수술을 시행 받았다. 36명은 광투시 진입기구만을 사용하였고(나이 <14), 31명은 흉강경을 추가로 이용하였다(나이 ${\geq}14$). 너스 수술 중이나 후에 흉강내 대량 출혈이나 장기손상 같은 주요합병증은 얼었다. 너스 수술에서 광투시 진입기구를 사용함으로써 출혈과 장기 손상 등 치명적인 합병증 없이 안전하고 간단하게 전종격동 박리를 할 수 있었다.

구강악안면재건을 위한 복직근 유리피판의 해부학적 고찰 (Anatomical Review of Rectus Abdominis Muscle Free Flap for the Oral and Maxillofacial Reconstruction)

  • 박정민;서미현;김성민;강지영;명훈;이종호
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제34권5호
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    • pp.367-375
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    • 2012
  • Midfacial reconstruction following resection of extensive malignant oral cavity tumors constitutes a challenging problems for reconstructive surgeons. Rectus abdominis muscle free flap (RAMFF) can be considered as the optimal reconstructive option in this case, because this flap has some advantages including consistent deep inferior epigastric artery anatomy, easy to dissect with well defined skin boundaries, acceptable donor site morbidity and the ability to perform simultaneous flap harvest with oral cancer ablation surgery. The rectus abdominis muscle forms an important part of the anterior abdominal wall and flexes the vertebral column, which is a long strap-like muscle divided transversely by three tendinous intersections, fibrous bands which are adherent to the anterior rectus sheath, which is thickly enclosed by the rectus sheath, except for the posterior part below the arcuate line that is usually located midway between the umbilicus and symphysis pubis. Below the arcuate line, this muscle lies in direct contact with the transversalis fascia and parietal peritoneum. For the better understanding of RAMFF as a routine reconstructive procedure in oral and maxillofacial surgery, the constant anatomical findings muse be learned and memorized by the young doctors in the course of the special curriculum periods for the Korean national board of oral and maxillofacial surgery. This review article will discuss the anatomical basis of RAMFF with Korean language.

악교정수술 후 발생한 종격기종과 기흉: 증례보고 (PNEUMOMEDIASTINUM AND PNEUMOTHORAX AFTER ORTHOGNATHIC SURGERY: A CASE REPORT)

  • 김한림;윤경인;최영준;손동섭
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제32권3호
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    • pp.246-250
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    • 2010
  • Mediastinal emphysema, also referred to as pneumomediastinum or Hamman's syndrome, is defined as the presence of air or gas within the fascial planes of the mediastinum. Superior extension of air into the cervicofacial subcutaneous space via communications between the mediastinum and cervical fascial planes or spaces occurs occasionally. The mediastinal air may originate from the respiratory tract, the intrathoracic airway, the lung parenchyma, or the gastrointestinal tract. The presence of air in the mediastinum may be spontaneous, iatrogenic or due to penetrating trauma. Pneumothorax is defined as the presence of air or gas within the pleural cavity. A pneumothorax can occur spontaneously. It can also occur as the result of a disease or injury to the lung or due to a puncture to the chest wall. Pneumomediastinum and pneumothorax is a rare complication of head and neck surgery. Nevertheless, when it occurs, it is usually considered to result from direct dissection by the air at the time of injury or of surgery. Most of the cases of pneumomediastinum and pneumothorax that have been described in the oral and maxillofacial surgery literature result from air dissecting down the fascial planes of the neck. The authors report a case with subcutaneous emphysema, pneumomediastinum and pneumothorax after orthognathic surgery.

수지동맥천공지피판술과 볼점막 이식을 통한 조갑상 손상 치험 1례 (A Case Report of Nail Bed Reconstruction with Digital Artery Perforator (DAP) Flap and Buccal Mucosal Graft)

  • 이용우;김연환;김정태
    • Archives of Plastic Surgery
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    • 제38권1호
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    • pp.113-116
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    • 2011
  • Purpose: Many fingertip injuries are associated with nail injury and it is hard to repair to original shape due to its unique characteristic. Mucosal graft is used for a defect of the nail bed injury. Hereby, we introduce a DAP flap and buccal mucosal graft, with which we could reduce the defect size of the injured fingertip and donor site morbidity at the same time, without any need for harvesting additional skin from other part of hand. Also, mucosal graft makes good cosmetic and functional outcome of nail. Methods: This method was performed in a 56-year-old man with fingertip injury on dorsal side of left thumb due to electrical saw. First, DAP flap was performed on the injured finger to reduce the size of the defect of fingertip and cover the bone exposure. Second, nail bed part of the DAP flap was de-epithelized and buccal mucosal graft was done from left side of intraoral cavity wall. Results: Flap and graft survived without any necrosis but some nail bed could not be covered with flap due to insufficient flap size. All wounds healed well and did not present any severe adversary symptoms. Conclusion: DAP flap with mucosal graft is an effective method that we can easily apply in reconstruction of fingertip injury. We suggest that the combination of the two procedures makes good functional and cosmetic outcome compared to the usual manner, especially in cases of nail bed injury without distal phalanx bone defect.

경비주 접근법으로 안면부 손상없이 제거한 비전두 유피낭종 1예 (A Case of Nasofrontal Dermoid Cyst Via Transcollumelar Approach)

  • 이강현;이성민;김상욱;박기준;김동규
    • 대한두경부종양학회지
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    • 제36권1호
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    • pp.27-31
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    • 2020
  • The midline nasal dermoid cysts are rare congenital neoplasms, which are diagnosed frequently in childhood. Masses are often noticeable at birth gaining size over time with recurrent infections and usually arise from the nasal cavity or lower 1/3 of the nasal dorsum. CT scan as the primary investigation is helpful to determine accurately the size and extent of the lesion as well as the integrity of adjacent bony structures. MRI scan is recommended to rule out an intracranial extension or sinus tracts. Treatment of choice is the complete surgical excision preserving the cyst wall. Here in, we present an unusual case of nasofrontal dermoid cyst in a 19-year-old boy without radiographic evidence of transcranial extension. In this case, we surgically removed nasofrontal dermoid cyst via transcolumellar approach. We also corrected saddle nose deformity after mass removal. Therefore, in this case, we experienced a successful case in which the nasofrontal dermoid cyst was totally removed without facial scar and deformity.

홀스타인 미경산우에서 질수증을 동반한 무공질판막 일례 (A Case of Imperforate Hymen with Hydrocolpos in a Holstein Heifer)

  • 김일화;강현구;허태영
    • 한국임상수의학회지
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    • 제29권4호
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    • pp.348-351
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    • 2012
  • 질을 경유한 반복된 인공수정 실패의 병력을 가진 17개월령 홀스타인 미경산우에서, 질경 검사로 바깥요도구멍 후방에 무공질판막의 존재를 확인하였으며, 이것은 질벽과 비슷한 외관을 보여주었다. 초음파검사 결과 질판막과 자궁경 사이 질강 내에 저에코성 액체의 존재, 즉 질수증의 동반을 확인하였다. 미경산우를 진정 및 경막외마취 후, 수술용 칼과 가위로 무공질판막을 절개 및 제거하였으며, 절개 부위는 단순결절봉합 하였다. 미경산우는 약 20일 간격의 3회 연속 발정에 따른 인공수정 후 임신되었으며, 수정일로부터 291일 경과 후 건강한 수컷 송아지를 순산하였다. 본 증례는 홀스타인 미경산우에서 질수증을 동반한 무공질판막의 발생과 질판막의 제거 수술 후 성공적인 인공수정, 임신 및 분만을 보고한다.

Lactococcus lactis 1370가 인공치태 형성에 미치는 영향 (Effect of Lactococcus lactis 1370 on the Formation of Artificial Plaque)

  • 정진;임성이;오종석
    • 대한미생물학회지
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    • 제35권1호
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    • pp.77-85
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    • 2000
  • Streptococcus mutans is the most important causative bacteria of dental caries among the oral bacteria. Lactococcus lactis 1370 was isolated from the oral cavity of child. The effect of Lactococcus lactis 1370 on the formation of artificial plaque by Streptococcus mutans was studied. 1. The insoluble substances and bacteria were much more attached on the wall of disposable cuvette in the culture of Streptococcus mutans than in the combined culture of Streptococcus mutans and Lactococcus lactis 1370. 2. The mean weight of produced artificial plaque on the wires in the beaker was 131.7 mg in the culture of Streptococcus mutans only, whereas being reduced to 6.4 mg in the combined culture of Streptococcus mutans and Lactococcus lactis 1370 (p<0.05). The viable cell didn't show the significant difference between them after culturing. 3. When Streptococcus mutans was cultured in the media containing culture supernatant of Lactococcus lactis 1370 cultured in M17 broth containing 0.5% yeast extract and 5% sucrose, the mean weight of produced artificial plaque was 8.0 mg on the wires, whereas being 125.4 mg in the media without culture supernatant of Lactococcus lactis 1370 (p<0.05). The viable cell didn't show the significant difference between them after culturing. 4. When Streptococcus mutans was cultured in the media containing soluble polymer produced by Lactococcus lactis 1370, the mean weight of produced artificial plaque was significantly reduced compared with being cultured in the media without soluble polymer (p<0.05). The viable cell didn't show the significant difference between them after culturing. 5. The soluble polymer produced by Lactococcus lactis 1370 was glucan. 6. The glucan produced by Lactococcus lactis 1370 was water-soluble glucan containing ${\alpha}$-1,6-glucose linkage as the main linkage. These results suggest that the artificial plaque formed by Streptococcus mutans is inhibited by water-soluble glucan produced by Lactococcus lactis 1370.

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양식넙치, Paralichthys olivaceus 치어의 스쿠티카충 감염경로 (Infection Route of Scuticociliates in the Juvenile of the Cultured Flounder, Paralichthys olivaceus)

  • 진창남;이창훈;오상필;나오수;허문수
    • 한국어병학회지
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    • 제16권1호
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    • pp.13-21
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    • 2003
  • The infection characteristics with scuticociliates at on-land rearing farms and hatcheries of flounder, Paralithys olivaceus was investigated during the year of 2001 by juvenile infection routes. When culture tanks for living food organisms such as chlorella, rotifer, and Artemia were searched, scuticocilates were detected both in live and dead rotifer, and at the dregs of culture tank bottoms at almost hatcheries. When rotifer infected with scuticocilates fed on fish larvae, lots of scuticocilate were inhabited at the bottom of fry rearing tanks. After feeding on scuticocilates-infected rotifer on fish larvae, first infection was detected at 10 days after bottom dwelling or 40 days old after hatching. By histopathological examination we confirmed the infection route of eyeball or brain contamination was that the ciliate worms digged through mouth and front part of the dosal fin cuticle, transferred into eyeball along the epithelium and muscle tissue, and reached finally into brain by the muscle and nerve tissue. The infection of internal organs was clarified into two routes. The first route was started from the infection at ventral and anal fin rays by the worms, and reached at the anus and rectum through the epithelium and muscle tissue. The second route was initiated from the infection at urinary organ and reached into the rectum epithelium cells, inner wall of intestine, abdominal cavity, pancreas, kidney, and pancreas. At seed production farms where fish larvae fed on scuticocilate-free rotifer, the worms were not detected not only at the food organisms culture tanks and juvenile rearing tanks but also larval flounder less than 7cm in total length.

Buongiorno의 비균질 모델을 사용한 나노유체의 층류 자연대류 해석 (COMPUTATION OF LAMINAR NATURAL CONVECTION OF NANOFLUID USING BUONGIORNO'S NONHOMOGENEOUS MODEL)

  • 최석기;김성오;이태호
    • 한국전산유체공학회지
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    • 제18권4호
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    • pp.25-34
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    • 2013
  • A numerical study of a laminar natural convection of the CuO-water nanofluid in a square cavity using the Buongiorno's nonhomogeneous model is presented. All the governing equations including the volume fraction equation are discretized on a cell-centered, non-uniform grid employing the finite-volume method with a primitive variable formulation. Calculations are performed over a range of Rayleigh numbers and volume fractions of the nanopartile. From the computed results, it is shown that both the homogeneous and nonhomogeneous models predict the deterioration of the natural convection heat transfer well with an increase of the volume fraction of nanoparticle at the same Rayleigh number, which was observed in the previous experimental studies. It is also shown that the differences in the computed results of the average Nusselt number at the wall between the homogeneous and nonhomogeneous models are very small, and this indicates that the slip mechanism of the Brown diffusion and thermophoresis effects are negligible in the laminar natural convection of the nanofluid. The degradation of the heat transfer with an increase of the volume fraction of the nanoparticle in the natural convection of nanofluid is due to the increase of the viscosity and the decrease of the thermal expansion coefficient and the specific heat. It is clarified in the present study that the previous controversies between the numerical and experimental studies are owing to the different definitions of the Nusselt number.