• Title/Summary/Keyword: Tube Life

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ISM에 의한 발전용 고온 배관재료 2.25Cr1Mo강의 고온 크리프 수명 예측에 관한 연구

  • Lee, Sang-Guk;Jeong, Min-Hwa;O, Se-Gyu;Song, Jeong-Geun
    • Journal of Ocean Engineering and Technology
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    • v.12 no.2 s.28
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    • pp.71-78
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    • 1998
  • In this report for the assessment of creep properties of high-temperature tube materials in power plants, the long-time($10^4$~105h) creep life prediction by ISM for 2.25Cr1Mo steel was studied. It was clarified experimentally and quantitatively that the newly developed long-time creep life prediction equation was very coincident with the actual experimental data with high confidence, and the model was $t_r=\alpha\varepsilon_0^{\beta}\sigma^{-1}$.

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Precise Diagnosis Technology for Power Plant Boiler (발전용 보일러 정밀진단기술)

  • Park, Min-Su;Kim, Jong-Oh
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.914-919
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    • 2000
  • In most case high temperature components in fossil power plant are damaged by fatigue, creep and degradation. Design of power plant components is based on ideal loading such as temperature, pressure and so on. But in many cases unexpected loadings are applied at components. A key ingredient in plant life extension is the preventive diagnosis technology and remaining-life-assessment technology. This paper describes diagnosis technology and life-assessment technology for power plant boiler. It helps in setting up proper inspection schedules, maintenance procedures, and operating procedure.

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Effects of Incubation and Thawing Temperature on Frozen-thawed Stallion Epididymal Spermatozoa (말의 정소상체 정자의 동결 후 해동 온도 및 Incubation의 효과)

  • Kim, Keun-Jung;Lee, Kyung-Bon;Lee, Ji-Hye;Kim, Eun-Young;Han, Kil-Woo;Park, Kang-Sun;Kim, Min-Kyu
    • Journal of Embryo Transfer
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    • v.28 no.3
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    • pp.297-302
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    • 2013
  • Cryopreservation of epididymal spermatozoa offers a potential tool for rescuing genetic material from males of genetically elite populations. Castration, catastrophic injury, sudden death or any other event that makes semen collection or mating impossible may prematurely terminate a stallion reproduction. Stallion epididymal spermatozoa vary widely in the loss of progressive motility, acrosomal integrity, and viability during freezing and thawing. The objective of this work was to investigate the effect of (1) freezing package types on cryopreservation efficiency, (2) thawing temperatures (37, 56 or $70^{\circ}C$) on Computer Assisted Sperm Analysis (CASA) parameters and (3) post-thawing incubation time (0, 1, 2 or 4h) on castrated stallion epididymis. Post-thawed sperm motility ranged between 59.69% and 64.28% ($56^{\circ}C$ and $37^{\circ}C$) in various thawing temperatures. When stallion epididymis sperm was frozen, straw was better than freezing tube on VCL (Velocity of Curvilinear Line) and VAP (Velocity of Average Path) parameter. Higher percentage of motility was observed at $37^{\circ}C$ thawing temperature even though no significant difference was observed among various temperatures. The motility, VCL, ALH (Amplitude of Lateral Head displacement), VAP, BCF (Beat-Cross Frequency) and STR (Straightness index) parameter of post-thawed sperm were significantly decreased by increasing the incubation time for all thawing temperatures. The present study showed that type of freezing package (Straw vs. Freezing tube) was not significantly different on cryopreservation efficiency. Furthermore, stallion epididymal spermatozoa frozen-thawed at $37^{\circ}C$ for 1 min resulted the highest proportion of motility and velocity movement. In addition, motility and viability of frozen-thawed stallion epididymal spermatozoa were also decreased by incubation.

Evaluation on the Creep Life Prediction Using Initial Strain Method (초기 연신율법을 이용한 크리프 수명예측 평가)

  • Kong, Yu-Sik;Lim, Man-Bae;Lee, Sang-Pill;Yoon, Han-Ki;Oh, Sae-Kyoo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.6
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    • pp.1069-1076
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    • 2002
  • The high temperature creep behavior of heat machine systems such as aircraft engines, boilers and turbines in power plants and nuclear reactor components have been considered as an important and needful fact. There are considerable research results available for the design of high temperature tube materials in power plants. However, few studies on the Initial Strain Method (ISM) capable of securing repair, maintenance, cost loss and life loss have been made. In this method, 3 long time prediction Of high temperature creep characteristics can be dramatically induced through a short time experiment. The purpose of present study is to investigate the high temperature creep lift of Udimet 720, SCM 440-STD61 and 1Cr-0.5Mo steel using the ISM. The creep test was performed at 40$0^{\circ}C$ to $700^{\circ}C$ under a pure loading. In the prediction of creep life for each materials, the equation of ISM was superior of Larson-Miller Parameter(LMP). Especially, the long time prediction of creep life was identified to improve the reliability.

Simultaneous Detection and Identification of Bacillus cereus Group Bacteria Using Multiplex PCR

  • Park, Si-Hong;Kim, Hyun-Joong;Kim, Jae-Hwan;Kim, Tae-Woon;Kim, Hae-Yeong
    • Journal of Microbiology and Biotechnology
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    • v.17 no.7
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    • pp.1177-1182
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    • 2007
  • Bacillus cereus group bacteria share a significant degree of genetic similarity. Thus, to differentiate and identify the Bacillus cereus group efficiently, a multiplex PCR method using the gyrB and groEL genes as diagnostic markers is suggested for simultaneous detection. The assay yielded a 400 bp amplicon for the groEL gene from all the B. cereus group bacteria, and a 253 bp amplicon from B. anthracis, 475 bp amplicon from B. cereus, 299 bp amplicon from B. thuringiensis, and 604 bp amplicon from B. mycoides for the gyrB gene. No nonspecific amplicons were observed with the DNA from 29 other pathogenic bacteria. The specificity and sensitivity of the B. cereus group identification using this multiplex PCR assay were evaluated with different kinds of food samples. In conclusion, the proposed multiplex PCR is a reliable, simple, rapid, and efficient method for the simultaneous identification of B. cereus group bacteria from food samples in a single tube.

Effect of Topophysis and Uniting Method of Rootstock and Scion on Rooting and Subsequent Growth of Stenting-propagated (Cutting-grafted) Roses (접수의 채취부위 및 접수와 대목의 고정법에 따른 장미 접삽묘의 생육 특성)

  • Park, Yoo-Gyeong;Jeong, Byoung-Ryong
    • Horticultural Science & Technology
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    • v.28 no.3
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    • pp.456-461
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    • 2010
  • A study was conducted to investigate the effect of topophysis, and uniting method of rootstock and scion on rooting and subsequent growth of stenting-propagated cut rose ($Rosa$ $hybrida$ Hort.) in an effort to develop an efficient stenting propagation method for domestic rose cultivars. Four cultivars used in this study were two standard type cultivars 'Sweet Yellow' and 'Hanmaum', and two spray type cultivars 'Chelsi' and 'May'. Scions were grafted on cuttings of a rootstock $Rosa$ $indica$ 'Major'. The stenting-propagated scion-rootstock unions were planted in rockwool cubes ($50{\times}50{\times}50mm$, Delta, Grodan, Denmark) and were placed in a graft-take chamber for five days before being placed on misted greenhouse beds. The rootstock was removed of all leaves and nodes. Both the base of scions and top of stocks were simultaneously cut at a $45^{\circ}$ angle for grafting. Scions were prepared as single node cuttings, each with a five-leaflet leaf. Three positions of topophysis used were 7-9th (top), 4-6th (middle), and 1st-3rd (bottom) nodes from the stem base. Four uniting materials used were tube, tube + parafilm wrap, tube + clothespin, and clothespin. Rooting and growth were affected by the topophysis and cultivar. The best topophysis for rooting was 7-9th (top) nodes in all cultivars. Topophysis affected percent rooting, and number of roots, length of the longest root, and but not weight, shoot length and graft-take. Rooting and growth were affected by the uniting method and cultivar. Tube uniting method generally showed higher percentage graft-take, percent rooting, and number of roots than other methods. However, rootstock and scion union was not complete in this treatment. On the whole, the greatest rooting and subsequent growth of stenting-propagated plants were found in the tube + clothespin method. Except 'Sweet Yellow', rooting and growth were not adequate in the clothespin method. The results suggested that a tube + clothespin method was the most effective, and this method may be used as a substitute to save labor compared to a tube + parafilm wrap method which is currently being used in commercial nurseries.

Reconstruction of tracheal stenosis: report of one case (기관협착증 치험 1)

  • 윤갑진
    • Journal of Chest Surgery
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    • v.17 no.3
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    • pp.492-496
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    • 1984
  • For the treatment of acute respiratory failure and emergency care of an urgent patient, tracheostomy in itself may have been a life saving procedure. But, tracheal stenosis gives serious clinical manifestation which can only be corrected by surgical intervention in many occasions. We experienced one case of tracheal stenosis following tracheostomy for assisted ventilation. Tracheogram showed a 4.0 cm segmental narrowing below the tracheostoma. Before reconstruction, we tried to T-tube cannulation, but the result was not satisfactory. So we resected the narrowed segment and tracheal reconstruction was performed with uneventful result.

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Intrapulmonary teratoma -Report of a case- (폐실질내 기형종 -1례 보고-)

  • 박도웅
    • Journal of Chest Surgery
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    • v.22 no.1
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    • pp.158-162
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    • 1989
  • This paper reports a case in a 16-year-old female of intrapulmonary teratoma located in the right upper and middle lobes of the lung. The initial symptoms were high spiking fever, cough and chest pain. Initial chest X-ray revealed large homogenous mass in the right upper and middle lung fields. So intercostal tube drainage was done under the impression of the lung abscess. But mass density was remained on the follow-up chest X-ray, the patient had resection of the right upper and middle lobes of the lung. The gross and microscopic findings of the resected specimen revealed characteristic findings of the intrapulmonary teratoma. The patient is asymtomatic at present and living a normal life.

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곡면가공 NC 테이터 생성을 위한 전문가 시스템

  • 신긍철;정선환
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.676-680
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    • 1994
  • Recently the needs for the experts who can solve the complex problem arising at the special areas are continuously increasing in our social life. So many researchers have studied about the expert systems as a part of an artificial intelligence during last two decades. This study was carried out in order to develope an expert system, ESSM, for the NC data generation to machine the curved surface of a forming die to fabricate the shadow mask of TV Brown Tube.

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Re-expansion Pulmonary Edema -2 Cases Report- (재팽창 폐부종 치험 2례 보고)

  • 강경민
    • Journal of Chest Surgery
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    • v.28 no.1
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    • pp.81-84
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    • 1995
  • Re-expansion pulmonary edema following pneumothorax or hemothorax is clinically uncommon but occasionally life threatening. Clinical details are given of two patients.Ipsilateral pulmonary edema were developed after chest tube insertion due to spontaneous pneumothorax in case I and after evacuation of postoperative hemothorax in case II. The patients were treated with frequent bronchial toilet.The administration of colloid solution and diuretics was effective. The possible mechanisms underlying the edema are discussed.Both increased time of collapse and suction tended to correlate with reexpansion edema.The present two cases provided evidence for longstanding lung collapse and immediate application of suction.

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