• Title/Summary/Keyword: Pressure-tightness

Search Result 83, Processing Time 0.029 seconds

Comparison of Continuous Appositional Suture Patterns for Cystotomy Closure in Ex Vivo Swine Model

  • Sang-hun Park;Joo-Myoung Lee;Hyunjung Park;Jongtae Cheong
    • Journal of Veterinary Clinics
    • /
    • v.39 no.6
    • /
    • pp.353-359
    • /
    • 2022
  • Several suture patterns can be used for cystotomy closure, and a continuous suture pattern is the most commonly used. In this study, the fluid-tight ability and other suitabilities of continuous appositional sutures, such as the simple continuous suture pattern (SC), running suture pattern (RN), and Ford interlocking suture pattern (FI), were compared for cystotomy closure. Cystotomy closure was performed using each suture method in 10 cases of ex vivo swine bladders in each group. Suture time, leakage site, suture length, bursting pressure (BP), bursting volume (BV), and circular bursting wall tension (CBWT) were measured. Suture time and suture length were the shortest in RN and the longest in FI. Leakage occurred in two places: the incision line directly and the hole made by the suture. Leakage occurred through the incision line in 4 bladders of the RN group and 2 bladders of the FI group, but not in the SC group, and in the rest of the bladders, leakage occurred through the suture hole. The values of BP, BV, and CBWT increased in the order of FI, SC, and RN. Suture time and suture length can be considered as factors related to healing and side effects. In this study, leakage through the incision was found in a less appositional area; therefore, leakage through the hole could be considered an indicator of better apposition. Good apposition is one of the conditions required for ideal cystotomy closure. The bursting strength representing the fluid-tight ability can be expressed as the CBWT. RN is expected to be efficient and cause a small degree of foreign body reaction; however, it is expected to be less stable. FI has the greatest fluid-tightness ability, but it has been proposed that side effects due to foreign body reactions most frequently occur in FI. In conclusion, SC, which is expected to have a sufficient degree of fluid-tightness and appropriate recovery, is preferable to other continuous appositional suturing methods for cystotomy closure.

Performance Analysis of a 50㎾ Turbo-Generator Gas Turbine Engine with a Recuperator (리큐퍼레이터를 고려한 50KW급 터보제너레이터 가스터빈 엔진의 성능해석)

  • 김수용;수다레프
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.3 no.2
    • /
    • pp.48-55
    • /
    • 1999
  • Performance analysis of a 50KW turbo-generator gas turbine engine with a recuperator was studied. Recuperated cycle has been employed to meet maximum fuel economy and ultra low emissions especially for military and vehicular engines. From thermodynamic stand point, it is known that recuperative cycle can contribute most to enhance thermal cycle efficiency for the Pressure ratios under 10 and of comparatively low turbine inlet temperature. Efficiency of a simple cycle with a recuperator increases relatively about 30% than without one at effectiveness of 0.5. Pressure losses in the heat exchanger less than 5.2% is considered in the design process. A tubular type heat exchanger is selected for this particular engine because it can provide simple construction as well as structural sturdiness and excellent leak tightness.

  • PDF

Evaluation of the Impacts of Stack Effect in High-Rise Buildings

  • Yang, In-Ho;Jo, Jae-Hun;Yeo, Myoung-Souk;Kim, Kwang-Woo
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • v.11 no.2
    • /
    • pp.91-103
    • /
    • 2003
  • The objective of this study is to analyze and evaluate the impact of the stack effect in high-rise buildings for solving the various problems resulting from it. For the evaluation of the impacts on the stack effect, computer program simulations based on the network model were performed for a typical high-rise office building. The results of the simulations show that the impact caused by the stack effect is mainly dependent on building envelope air-tightness and internal air flow resistance. Therefore the problems due to the stack effect may be solved to some extent by installing vestibules around entrance doors and doors serving elevators, and by zoning the elevators.

Deleyed Cardiac Tamponade After Open Heart Surgery (Two Cases Report) (개심술후에 발생한 지연성 심장압진증)

  • 김병열
    • Journal of Chest Surgery
    • /
    • v.15 no.2
    • /
    • pp.218-221
    • /
    • 1982
  • Delayed cardiac tamponade in an uncommon and frequently fatal complication after open-heart surgery. We had been experienced two cases of delayed cardiac tamponade as a complication of open-heart surgery and treated successfully by reinsertion of pericardial drain through subxiphoid route. First case was 60 years old female patient and underwent MVR under impression of MSi + Ti Second case was 19 years old male patient and underwent total correction of T.O.F.with Blalock shunt [Lt]. Both cases had Initial symptoms, which were epigastric pain, chest tightness, dropped blood pressure, and increased pulse rate and respiratory rate, mimic as low cardiac output syndrome after open-heart surgery. Roentgenogram of the chest showed a rapid increased cardiothoracic ratio. It is important to realize the presence of late cardiac tamponade for proper diagnosis of complication after open-heart surgery.

  • PDF

Fatigue Damage Behavior in TIG Welded Joint of F82H Steel under Low Cycle Fatigue Loading (저주기 피로부하에서 F82H 강 TIG 용접 접합부의 피로손상거동)

  • Kim, Dong-Hyun;Park, Ki-Won
    • Journal of Welding and Joining
    • /
    • v.33 no.6
    • /
    • pp.42-48
    • /
    • 2015
  • Reduced activation ferritic/martensitic steels are recognized as the primary candidate structural materials for fusion blanket systems. Welding is an inevitable for breeding blanket for pressure tightness and radioisotope confinement. Especially, TIG welding was chosen for sealing because it has the largest gap allowance compared to the other welding methods, and its properties are controllable by feed wire and welding conditions. In this study, the low cycle fatigue test using two-type gage such as extensometer and strain gage was applied to the TIG welded joint of F82H steel, for evaluating fatigue damage accumulation behavior of the HAZs. As the result, the over-tempered HAZ have shown a higher fatigue damage accumulation compared with other materials at all the testing conditions.

A Study of Electro-foaming Fusion Wrap for Polyethylene Sewer Pipe (폴리에틸렌 하수관 연결용 전기발포융착 이음관에 관한 연구)

  • Kye, Hyoung-San;Joo, Kyung-Hoon
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.26 no.3
    • /
    • pp.343-354
    • /
    • 2012
  • A electro-foaming fusion wrap fitting for polyethylene sewer pipe was built and foaming mechanism has been studied. A foaming sheet, supporting sheet and clamping band is assembled into a all-in-one structured electro-foaming fusion wrap fitting. To specify foaming and fusion of electro-foaming fusion wrap for PE sewer pipe, series of fusion tests were performed in various conditions. A parallel plate compression test up to 50 % of inner diameter deflection has been performed to check integrity of fusion quality and it was found that there were no visible signs of crack in wrapped area of fitting. Also air tightness test based on KS M 3511-2 has been performed to evaluate perfectness of wrap fusion quality and we found there were no pressure drop up to 10 times higher value than KS standard regulation.

Simulation of the Stack Effect in High-Rise Builbings (고층건물에서의 연돌효과 시뮬레이션)

  • 양인호;여명석;조재훈;김광우
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.14 no.6
    • /
    • pp.456-467
    • /
    • 2002
  • The objective of this study is to analyze and evaluate the impact of the stack effect in high-rise buildings for solving the various problems resulting from it. For the evaluation of the impact of the stack effect, computer program simulations based on the network model were performed for a typical high-rise office building. The results of the simulations show that the impact caused by the stack effect is mainly dependent on building envelope air-tightness and internal airflow resistance, so the problems due to the stack effect may be solved to some extent by installing vestibules around entrance doors and doors serving elevators, and by zoning the elevators.

Study on the Control Performance Evaluation of the Exhaust Stack used in High Riser Public House (초고층공동주택 국소배기용 입상덕트시스템의 제어성능평가에 관한 연구)

  • Kwon, Yong-Il;Ahn, Jung-Hun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.21 no.2
    • /
    • pp.103-108
    • /
    • 2009
  • Local exhaust system used in toilet and cooking place of low-rise public house installed roof ventilator at terminal of stack. There are many high riser public houses in Korea. These buildings were not viewed as being major contributors to exhaust pollutants producted in indoor. It was because many engineers thought that exhaust in high riser public house depends on stack effect. But Neutral pressure level represents in a terminal of stack with air tightness for the best exhaust efficiency. Thereby, lower floors have the worst indoor air quality. This paper focuses mainly on the exhaust efficiency improved by roof fan with motor installed in high riser public house. It is observed there is higher exhaust efficiency than the existing natural roof ventilator.

A Study on the Measurement of Airtightness Performance of Detached Houses in Chung-cheong area (충청지역 단독주택의 기밀성능 실측 연구)

  • Yoon, Jong-Ho;Park, Jae-Wan;Lee, Kwang-Sung;Baek, Nam-Choon;Shin, U-Cheul
    • Journal of the Korean Solar Energy Society
    • /
    • v.28 no.5
    • /
    • pp.65-71
    • /
    • 2008
  • The purpose of this study is to investigate an airtightness of typical Korean detached houses with field measurements. Air leakage testings by means of blower door test in accordance with ASTM E79-8 were measured in 22 detached dwellings in Daejeon and Geumsan. The results showed that detached dwellings have an average airtightness with ACH50/20 (air chang per hour at a pressure difference of 50 Pa between inside outside) of 0.82 $hr^{-1}$ which is a higher range than for typical apartments and leakage class G by normalized leakage area of ASHRAE.

Development of Relief Valves for the Domestic Gas-fired Hot Water Boilers (가정용 가스보일러 과압방지밸브의 개발 연구)

  • Kim Young Gyu;Kwon Jeong Rock;Kim Ji Yoon;Suh Joon Suk
    • Journal of the Korean Institute of Gas
    • /
    • v.4 no.1 s.9
    • /
    • pp.63-68
    • /
    • 2000
  • We have developed a new relief valve which is a safety device for the domestic gas-fired hot water boilers. The relief valve has been designed to expand the inner diameter of the inlet, the outlet and the seat of the valve considering the relief capacity, and also to separate the spring from the room heating water. Therefore, we could minimize the adhesion and/or obstruction of the inlet and the corrosion phenomena of the spring which used to be the problem of the conventional relief valves. Test results of the developed relief valve showed that the performance of the opening pressure, reseating pressure, tightness, endurance were excellent, and the operating boiler with developed relief valve was evaluated as very good. The standardization and application of the relief valve can provide the advantage of component exchange and easy maintenance and repair.

  • PDF