• Title/Summary/Keyword: Direct closure

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Comparative study of prediction methods of power increase and propulsive performances in regular head short waves of KVLCC2 using CFD

  • Lee, Cheol-Min;Seo, Jin-Hyeok;Yu, Jin-Won;Choi, Jung-Eun;Lee, Inwon
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제11권2호
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    • pp.883-898
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    • 2019
  • This paper employs computational tools to predict power increase (or speed loss) and propulsion performances in waves of KVLCC2. Two-phase unsteady Reynolds averaged Navier-Stokes equations have been solved using finite volume method; and a realizable k-ε model has been applied for the turbulent closure. The free-surface is obtained by solving a VOF equation. Sliding mesh method is applied to simulate the flow around an operating propeller. Towing and self-propulsion computations in calm water are carried out to obtain the towing force, propeller rotating speed, thrust and torque at the self-propulsion point. Towing computations in waves are performed to obtain the added resistance. The regular short head waves of λ/LPP = 0.6 with 4 wave steepness of H/λ = 0.007, 0.017, 0.023 and 0.033 are taken into account. Four methods to predict speed-power relationship in waves are discussed; Taylor expansion, direct powering, load variation, resistance and thrust identity methods. In the load variation method, the revised ITTC-78 method based on the 'thrust identity' is utilized to predict propulsive performances in full scale. The propulsion performances in waves including propeller rotating speed, thrust, torque, thrust deduction and wake fraction, propeller advance coefficient, hull, propeller open water, relative rotative and propulsive efficiencies, and delivered power are investigated.

고지재생연구(제15보) -제지 공정수 폐쇄화에 따른 오염 및 변화에 관한 연구- (Recycling of Wastepaper(XV) -Contamination of Process Water by System Closure-)

  • 조미선;윤혜정;류정용;신종호;송봉근
    • 펄프종이기술
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    • 제33권2호
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    • pp.32-40
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    • 2001
  • It is desirable to reduce the amounts of fresh water and reuse the recycled water in papermaking process. In an attempt to improve the efficiency of recycling water refining treatment and to enhance the productivity of OCC recycling mill, up flow anaerobic sludge blanket(UASB) reactor was developed and introduced to Korea recently. In order to maximize the operating efficiency and minimize the adverse side effects it is imperative to estimate and evaluate the total effects of new system, UASB on the whole OCC recycling process. This study was carried out with a view to investigate the effects of the high temperature and alkalinity of process water on the quality ad productivity of testliner of OCC recycling mill which is equipped with UASB reactor and almost closed. Another object of this study was searching for the best available use of UASB treated process water. The results were as follows; Reuse of UASB treated water characterized with high temp and alkalinity was useful to improve the strength and drainage properties of recycled OCC owing to its good points of promoting OCC disintegration and reducing the calcium hardness of process water. However, it might not be avoidable to induce the increase of dissolved solids in process water in accordance with direct introducing of UASB treated water into the former stage of OCC stock preparation. So it would be advisable to adopt the UASB treated water in the stage of clean, screened OCC stock.

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폐경색을 동반한 삼천판막 심내막염의 수술치험 -폐엽 절제술과 개심술의 동시 수술- (Operation of Tricuspid Valve Endocarditis with Pulmonary Infarction - Lobectomy with Open Heart Surgery)

  • 김성완;김덕실;조준용;전상훈;이응배;장봉현;이종태;김규태
    • Journal of Chest Surgery
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    • 제36권10호
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    • pp.776-779
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    • 2003
  • 기침과 고열을 주소로 8세 남아가 전원되었으며, 과거력상 출생시 작은 크기의 심실 중격결손이 있었다. 심장 초음파 검사상 삼첨판에 10${\times}$6mm 크기의 우종이 있었고 심실중격결손 및 중등도의 삼천판 폐쇄부전이 발견되었다. 혈액 균배양 검사에서는 메티씰린 저항성 황색포도구균이 나왔다. 충분한 항생제 치료에도 불구하고 열이 조절되지 않았으며 폐경색이 진행되었다. 정중 흉골 절개하에 혈전제거술 및 우측폐하엽 절제술을 먼저 시행하였으며, 체외순환 하에 우종제거술, 삼첨판 재건술 및 심실중격결손 폐쇄술을 시행하였다.

선천성 Valsalva 동 동맥류의 수술요법 (Surgical Treatment of Congenital Aneurysms of Sinus of Valsalva A report of 10 years` experience of 18 consecutive cases)

  • 김기봉;서경필
    • Journal of Chest Surgery
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    • 제18권2호
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    • pp.265-272
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    • 1985
  • Congenital aneurysm of sinus of Valsalva is one of the rare congenital heart disease, which is usually asymptomatic until rupture. The aneurysm usually ruptures into a cardiac chamber and produces an aorto-intracardiac fistula. Ruptured aneurysm is a grave lesion in that it causes heart failure and subsequent death. If, however, it is discovered in its early stages and operated on properly, it can be corrected with considerable success. Form January 1975 through December 1984, 18 consecutive patients with congenital aneurysm of sinus of Valsalva underwent corrective surgery using total cardiopulmonary bypass in our department of Thoracic Surgery. 1. The incidence was about 0.9% of surgical cases of congenital heart disease during that period. 2. 13 were males and 5 females, with ages ranging 12 years to 52 years. 3. Associated anomalies were VSD in 14, infundibular PS in 1, aberrant muscle band in RVOT in 1, and secondary aortic insufficiency in 9. 4. 17 were suggested to arise from right coronary sinus and 1 from noncoronary sinus; Among 17, 12 ruptured into right ventricle, and one from noncoronary sinus into right atrium. 5. Surgical correction was performed by means of direct suture closure with combined pledget or patch graft after aneurysm resection, and associated lesions were also corrected simultaneously. 6. There was only one case of operative mortality, and all the other patients were relatively uneventful in their follow-up studies.

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매복 상악 중절치의 교정적 처치에 관한 임상 증례 (ORTHODONTIC AND/OR PHYSIOLOGIC POSITIONING OF IMPACTED MAXILLARY CENTRAL INCISORS)

  • 임은경;최영철
    • 대한소아치과학회지
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    • 제21권2호
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    • pp.510-517
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    • 1994
  • It is a relatively common clinical experience to see a impacted maxillary central incisor. This is apparent at the dental age of about eight years and over, when the patient is in the early mixed dentition stage. The adjacent teeth may tilt toward the site of the missing tooth with resulting space closure and midline deviation. Most often, the central incisor is impacted labially. The labial impaction has been indicated as the most difficult to manage. Each of the current articles describing labial impactions shows at least one case with mucogingival recession or a minimal zone of attached gingiva. This report described the surgical uncovering and orthodontic-physiologic positioning methods with labially impacted maxillary central incisors. Through surgical exposure and direct bonding of lingual botton, the central incisors were brought into proper eruption path with elastic traction. The case 1 and 2 were treated with the physiologic erupting forces. The case 3 was applied with continuous orthodontic force. The case 1 and 2 resulted in good positioning, good esthetics and adequate width of keratinised gingiva. The case 3 resulted in local inflammation and inadequate width of keratinised gingiva.

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대동맥동 동맥루 파열 -수술치험 6예- (Ruptured Aneurysm of Aortic sinus of Valsalva -A Report of 6 Cases-)

  • 이종명
    • Journal of Chest Surgery
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    • 제7권2호
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    • pp.201-208
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    • 1974
  • The purpose of this paper is to present author's experience with 6 cases of ruptured aneurysm of sinus of Valsalva which were treated surgically during last 10 years. Among the 6 cases, 5 were male and one was female. All of them originated from the right coronary sinus and 5 cases were ruptured into the RV while remained one into RA. The diagnosis was obtained in 4 cases by cineangiocardiogram. Clinically, we had difficulties in differential diagnosis with combined cases of VSD with A.I. and had special experience in its differentiation during cardiac catheterization. By simultaneous trans-venous and trans-arterial catheterization, identified two catheter tips in the RV, and pull back tracing obtained aortic pressure directly from RV, and RA from RV pressure which were benefit in confirm ruptured aneurysm of the aortic sinus. Surgical correction was performed by means of direct suture closure or combined Teflon pledget Of patch enforcement graft after aneurysm resection by trans-RA or trans-RV approach. All patients had no history of bacterial endocarditis, syphilis, or tuberculosis and operative findings revealed intact coronary sinus except involved one moreover 3 cases combined with high VSD which uggested congenital in origin although pathologic reports revealed only fibrosis. Post-operative course were uneventful in all cases but one who had bleeding and 2 months to 9 years follow up results were good and spend their usual life in all cases.

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운동유발성 기관지천식으로 오인된 성대 기능 이상 1례 (A Case of Vocal Cord Dysfunction Masqueraded as Exercised-Induced Asthma)

  • 조창래;심선진;박상현;남순열;고윤석
    • Tuberculosis and Respiratory Diseases
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    • 제52권3호
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    • pp.265-270
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    • 2002
  • 운동유발성 호흡곤란으로 내원하여 운동유발성 천식으로 치료 하였으나 증상 호전이 없어 운동후 기관지 내시경을 시행하여 성대기능이상을 확진하고 치료한 운동유발성 성대기능이상 1례를 문헌고찰과 함께 보고하는 바이다.

Waste Isolation Pilot Plant Performance Assessment: Radionuclide Release Sensitivity to Diminished Brine and Gas Flows to/from Transuranic Waste Disposal Areas

  • Day, Brad A.;Camphouse, R.C.;Zeitler, Todd R.
    • Nuclear Engineering and Technology
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    • 제49권2호
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    • pp.450-457
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    • 2017
  • Waste Isolation Pilot Plant repository releases are evaluated through the application of modified parameters to simulate accelerated creep closure, include capillary pressure effects on relative permeability, and increase brine and gas saturation in the operations and experimental (OPS/EXP) areas. The modifications to the repository model result in increased pressures and decreased brine saturations in waste areas and increased pressures and brine saturations in the OPS/EXP areas. Brine flows up the borehole during a hypothetical drilling intrusion are nearly identical and brine flows up the shaft are decreased. The modified parameters essentially halt the flow of gas from the southern waste areas to the northern nonwaste areas, except as transported through the marker beds and anhydrite layers. The combination of slightly increased waste region pressures and very slightly decreased brine saturations result in a modest increase in spallings and no significant effect on direct brine releases, with total releases from the Culebra and cutting and caving releases unaffected. Overall, the effects on total high-probability mean releases from the repository are insignificant, with total low-probability mean releases minimally increased. It is concluded that the modified OPS/EXP area parameters have an insignificant effect on the prediction of total releases.

지선모반에서 발생한 결합조직형성 모종 (Desmoplastic Trichilemmoma Arising in a Nevus Sebaceus)

  • 심형섭;정성노;권호;임영민;이은정
    • Archives of Plastic Surgery
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    • 제35권1호
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    • pp.107-109
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    • 2008
  • Purpose: Desmoplastic trichilemmoma is a rare variant of trichilemmoma. Histologically, it has a typical characteristic of trichilemmoma with epithelium of central portion and dense fibrous interstitium. There are only 4 reported cases of desmoplastic trichilemmoma arised in a nevus sebaceus, so we present a case of desmoplastic trichilemmoma arised in a nevus sebaceus with literature review.Methods: A 46-year-old female was clinically diagnosed as nevus sebaceous on left side of the forehead. Considering the facial contour, the mass was totally excised elliptically and direct closure was feasible with undermining subcutaneous layer.Results: Pathology report confirmed desmoplastic trichilemmoma developed from a nevus sebaceus and all tumor margins were negative. There were no evidences of tumor recurrence after surgical treatment.Conclusion: Desmoplastic trichilemmoma developed from a nevus sebaceus is a very rare tumor. Variant tumors can be developed from nevus sebaceus, so surgeon should be cautious in excising the mass totally and confirm the final pathology report.

Review of Instant Release Fractions of Long-lived Radionuclides in CANDU and PWR Spent Nuclear Fuels Under the Geological Disposal Conditions

  • Choi, Heui Joo;Koo, Yang-Hyun;Cho, Dong-Keun
    • 방사성폐기물학회지
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    • 제20권2호
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    • pp.231-241
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    • 2022
  • Several countries, including Korea, are considering the direct disposal of spent nuclear fuels. The radiological safety assessment results published after a geological repository closure indicate that the instant release is the main radiation source rather than the congruent release. Three Safety Case reports recently published were reviewed and the IRF values of seven long-lived radionuclides, including relevant experimental results, were compared. According to the literature review, the IRF values of both the CANDU and low burnup PWR spent fuel have been experimentally measured and used reasonably. In particular, the IRF values of volatile long-lived nuclides, such as 129I and 135Cs, were estimated from the FGR value. Because experimental leaching data regarding high burnup spent nuclear fuels are extremely scarce, a mathematical modelling approach proposed by Johnson and McGinnes was successfully applied to the domestic high burnup PWR spent nuclear fuel to derive the IRF values of iodine and cesium. The best estimate of the IRF was 5.5% at a discharge burnup of 55 GWd tHM-1.