• 제목/요약/키워드: Wall following

검색결과 677건 처리시간 0.025초

OSKA형 연소실에서 충돌면크기변화가 디젤분무거동에 미치는 영향 (The Effect of Impinging Land Size on Diesel Spray Behavior in OSKA Type Combustion Chamber)

  • 임덕경;박권하
    • 한국자동차공학회논문집
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    • 제9권4호
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    • pp.18-26
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    • 2001
  • OSKA engine was developed to remove the dense core of injection sprays. The engine uses impinging spray on a small pip, which spray after impinging is broken into smaller drops and disperses into fee space in chamber. In this paper the pip size is analyzed to give more dispersion of spray and fuel vapor. The gas phase is modelled by the Eulerian continuum conservation equations of mass, momentum, energy and fuel vapour fraction. The liquid phase is modelled following the discrete droplet model approach in Lagrangian form, and the droplet wall interaction is modelled as a function of the velocity normal to impaction lands. The droplet distributions, vapor fractions and gas flows are analyzed for various injection pressure cases. Numerical results indicate that the land diameter of 5.6mm has the best performance of spray dynamics and vaporization in the test sizes.

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Effects of Different Sizes of Glass Beads on the Release of Sporocysts from Eimeria tenella Oocysts

  • You, Myung-Jo
    • Parasites, Hosts and Diseases
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    • 제52권3호
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    • pp.317-319
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    • 2014
  • The oocyst wall is severed by means of mechanical injury or chemical agents. This study reports the percentage of in vitro sporocyst release following mechanical shaking in the presence of varying sizes of glass beads. Glass beads measured 0.5, 1, and 3 mm in diameter and were shaken with the oocysts for different times ranging from 5 sec to 5 min. Approximately 80% of sporocysts were released with 5 min of shaking in the presence of 3 mm glass beads, as well as 30 sec with 0.5 mm beads and 1 mm glass beads. The release of sporocysts of E. tenella was most efficient using 1 mm glass beads and treatment times of 30 sec to 1 min. Therefore, the use of 1 mm glass beads with 30 sec to 1 min of agitation is recommended in order to maximize sporocyst release and recovery and to improve the yield of viable sporozoites for use in biochemical, tissue culture, and immunological applications of coccidia.

Boerhaave`s Syndrome: 치험1례 (Boerhaave`s Syndrome - One case report -)

  • 방정현;김호경;이두연
    • Journal of Chest Surgery
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    • 제24권4호
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    • pp.371-375
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    • 1991
  • Postemetic rupture of the esophagus is an intrathoracic catastrophe which is universally fatal if untreated immediately. We have experienced one case of Boerhaave`s syndrome at the Thoracic & Cardiovascular Surgery Yonsei University College of Medicine. He was 56 years old male who complained severe chest-pain, dyspnea with sudden vomiting after alcohol. Esophagogram showed barium leakage through rupture site on lower esophagus into left thoracic cavity. He had taken repair of the rupture site of lower esophagus and wrapping it with the body of the stomach wall because of relatively clean rupture margin even though 48 hours following the rupture. He has been uneventful in post-operative courses & he discharged with good conditions.

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심장관통자상의 응급수술 치험 3례 (Penetrating Wound of the Heart: A Report of Three Cases)

  • 김공수;지행옥;김근호
    • Journal of Chest Surgery
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    • 제4권1호
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    • pp.43-50
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    • 1971
  • Three patients who sustained penetrating stab wound of the heart have been treated successfully by emergency thoracotomy in the Department of Thoracic Surgery, Chonnam University Hospital. There were two knife and one glass wound. The location of the injury were all on the right ventricle, but in one patient, it was penetrated to ventricular septum. All patients were in shock with a systolic pressure under 60 mmHg when admitted to the emergency room. In one of the three patients, blood pressure was not detectable and subsequently cardiac arrest. Two patients required immediate thoracotomy because of intrathoracic hemorrhage and increased pericardial tamponade and the other one required prompt thoracotomy because of sudden onset of cardiac arrest. There were no death postoperatively. Two patients are living without any complication in 4 years and 4 weeks after operation. One who had penetrating wound to ventricular septum, turned to cardiac decompensation, but he is living now in 4$\frac{1}{2}$ years after operation. Exploratory thoracotomy should be performed immediately in all the patients in whom a penetrating wound of the heart or pericardial tamponade following a penetrating wound of the chest wall is suspected.

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경호기법에 의한 위급상황의 발견과 대처 방안에 관한 고찰 (The consideration about prevention ways of discovery of emergency situation which is based on guard techniques)

  • 공배완
    • 한국재난정보학회 논문집
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    • 제6권2호
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    • pp.11-20
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    • 2010
  • All of the people or objects which are contacted during the activity of guard are added to range of objects. guard has to notice decision, question proposal, observation, accomplish to be happened them at the same time recognizing the steps as soon as possible. Before a lot of information of client are shown, guard expert has to search observation of materialization, extension of reservation, notification of business and causes of danger through personal interviews. Rapid communication system has to be assumed and effective caution, protection and shelter and following prevention are cooperated as well as has to care about safe of guard object by a protective wall. And also has to get out of the ground, keep the large shape when moves, prevent the trials of attack from the assassinators after takeing control over weapons.

와동의 깊이 및 넓이의 변화가 Inlay 유지력에 미치는 영향에 관한 실험적 연구 (EXPERIMENTAL STUDY ON THE RETENTION FORCE OF INLAY CAVITY)

  • 한택선;최재경
    • 대한치과의사협회지
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    • 제9권7호
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    • pp.431-437
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    • 1971
  • The authors performed an experimental study on the retention force in cavities with various depth and width. We used the simple model cavities which were cylindrically formed to eliminate the unexpected influence during experiment, and obtained following results. 1. The retention force in the cavities with parallel wall was vigorous even in the small cavity and increased considerably followed by extending the cavity size. 2. The ratention force resulted more vigorously by that the depth became deeper than that the distance between the lateral walls became longer. 3. Compared with the retention force in the cavities which had the same frictional lateral surface, it was more vigorous in the deeper cavity than in the cavity which was longer distance between the lateral surfaces.

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터보 차져 DI 디젤엔진에 있어서 성능 및 배기배출물에 미치는 흡기 포트 선회 유동 및 연료 분사계의 성능 (Effects of Intake Port Swirl and Fuel Injection System on the Performance and Exhaust Emissions in a Turbocharged DI Diesel Engine)

  • 윤준규;차경옥
    • 한국분무공학회지
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    • 제10권3호
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    • pp.45-53
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    • 2005
  • The purpose of this study is to analyze that intake port swirl and fuel injection system have an effect on the engine performance in a turbocharged D.I. diesel engine of the displacement 9.4L. As result of steady flow test, when the valve eccentricity ratio moved to cylinder wall, the flow coefficient and swirl intensity is increased. And as the swirl is increased, the mean flow coefficient is decreased, whereas the Gulf factor is increased. Through this engine test, it can be expected to meet performance and emissions by the following applied parameters; the swirl ratio is 2.43, injection timing is BTDC 13oCA and compression is 15.5.

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기관 캐뉼 발거 곤란증 (Decannulation Difficult)

  • 봉정표;임구일;유기원;이준규;박성원;홍기수
    • 대한기관식도과학회지
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    • 제4권2호
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    • pp.165-170
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    • 1998
  • Background and Objectives : Decannulation failure may result from factors such as inadequate ability 0 clear secretion, mucosal induration, granulation tissue, restenosis, tracheal wall depression and vocal cord palsy. We were to evaluate the effectiveness of surgical treatment on the basis of site and type of stenosis. Materials and Method : A series of 44 cases of decannulation difficulty between 1993 and 1997 were reviewed. The following data were collected on each of these patients : primary disease, indication for tracheostomy, site of stenosis, endoscopic findings of stenosis, surgical techniques used for treatment. Results : Primary diseases were 30 head trauma, 4 neck injury, 10 other diseases. Indication for tracheostomy were 37 prolonged intubation, 4 emergency tracheostomy, 3 laryngeal trauma. Endoscopic findings of stenosis were 24 granulation tissue, 16 laryngotracheal collapse, 4 combined with granulation tissue and collapse. Site of stenosis were 3 glottic, 9 subglottic, 24 stomal, 1 substomal, 7 mixed. 22 of 24 cases were decannulation using endoscopic treatment. Conclusion : The most common cause of failed decannulation was sternal granulation tissue. The most effective treatment of granulation tissue was endoscopic technique.

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후인두 농양을 초래한 식도이물 1례 (A Case of Retropharyngeal Abscess Caused by Esophagal Foreign Body)

  • 박병원;김명구
    • 대한기관식도과학회지
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    • 제4권2호
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    • pp.254-257
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    • 1998
  • Esophageal foreign body are not uncommon problems in the otolaryngologic field. Esophageal foreign body may cause severe complications such as esophageal ulceration, esophageal perforation, periesophagitis, tracheo-esophageal fistula, mediastinitis, pneumothorax pyothorax according to the kinds, shape, size, duration of lodgement of foreign body. The majority of esophageal foreign U which lodge in the esophagus can be removed endoscopically, but the following type of foreign body may require removal by external route. 1. an impacted foreign body 2. a foreign body producing esophagitis after unsuccessful attempts at removal through the esopahgoscope 3. a periesophageal abscess with a foreign body lodging in the abscess itself. Recently, we experienced a case of esophageal foreign body (fish bone) which penetrate the cervical esophageal wall and formed retropharyngeal abscess in 54-year old female. The foreign body are successfully removed and abscess was drained by external route through the lat neck.

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원관내 맥동유동의 열전달에 관한 실험적 연구 (An Experimental Study on Heat Transfer in the Pulsating Pipe Flow)

  • 박희용;김창기
    • 설비공학논문집
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    • 제3권1호
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    • pp.78-85
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    • 1991
  • An experimental result for heat transfer of pulsating turbulent pipe flow was presented under the condition of fully developed dynamic regime and uniform wall heat flux. Experiments were performed at following conditions ; Inlet time-averaged Reynolds number varied from 5000 to 11000; The peak pressure fluctuation were 1.3, 2.3 and 3.5 percent of the mean pressure; Pulsating frequency ranged from 53 Hz to 320 Hz The measurements showed that the effect of pulsation on local heat transfer is greater at downstream, in which pulsating source exists, than upstream and the heat transfer rate, averaged over the pipe length, was higher or lower than in an equivalent non-pulsating flow according to the pulsating conditions. In addition, the significant change of heat transfer rate was observed in acoustically resonant conditions, when the pulsating frequency of the flow corresponded to the pipe natural frequency.

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