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Experimental assessment of thermal radiation effects on containment atmospheres with varying steam content

  • R. Kapulla;S. Paranjape;U. Doll;E. Kirkby;D. Paladino
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.4348-4358
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    • 2022

  • The thermal-hydraulics phenomena in a containment during an accident will necessarily include radiative heat transfer (i) within the gas mixture due to the high radiative absorption and emission of steam and (ii) between the gas mixture and the surrounding structures. The analysis of some previous PANDA experiments (PSI, Switzerland) demonstrated the importance of the proper modelling of radiation for the benefit of numerical simulations. These results together with dedicated scoping calculations conducted for the present experiments indicated that the radiative heat transfer is considerable, even for a very low amount of steam (≈2%). The H2P2 series conducted in the large-scale PANDA facility at the Paul-Scherrer-Institut (PSI) in the framework of the OECD/NEA HYMERES-2 project is intended to enhance the understanding of thermal radiation phenomena and to provide a benchmark for corresponding numerical simulations. Thus, the test matrix was tailored around the two opposite extremes: either gas compositions with small steam content such that radiative heat transfer phenomena can be neglected. Or gas mixtures containing larger amounts of steam, so that radiative heat transfer is expected to play a dominant role. The H2P2 series consists of 5 experiments designed to isolate the radiation phenomena from convective and diffusive effects as much as possible. One vessel with a diameter of 4 m and a height of 8 m was preconditioned with different mixtures of air / steam at room and elevated temperatures. This was followed by the build-up of a stable helium stratification at constant pressure in the upper part of the vessel. After that, helium was injected from the top into the vessel which leads to an increase of the vessel pressure and a corresponding elevation-dependent and transient rise of the gas temperature. It is shown that even the addition of small amounts of steam in the initial gas atmosphere considerably impacts the radiative heat transport throughout all phases of the experiments and markedly influences i) the monitored gas peak temperature, ii) the temperature history during the compression and iii) the following relaxation phase after the compression was stopped. These PANDA experiments are the first of its kind conducted in a large scale thermal-hydraulic facility.

  • https://doi.org/10.1016/j.net.2022.07.001 인용 PDF KSCI

A Case of Rapidly Developed Obesity Hypoventilation Syndrome in a Patient with Kyphoscoliosis (척추후측만증 환자에서 급속히 진행된 비만성 저환기 증후군 1례)

  • Kim, Min Young;Jeong, Jee Sun;Jang, Yu Na;Go, Se-eun;Lee, Sang Haak;Moon, Hwa Sik;Kang, Hyeon Hui
    • Sleep Medicine and Psychophysiology
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    • v.22 no.1
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    • pp.30-34
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    • 2015

  • Obesity hypoventilation syndrome (OHS) is characterized by severe obesity, excessive daytime sleepiness, hypoxemia and hypercapnea. Because OHS mimics pulmonary hypertension or cor pulmonale, clinicians should recognize and treat this syndrome appropriately. A 58-year-old female visited the emergency room because of dyspnea. She was obese and had kyphoscoliosis. The patient also experienced snoring, recurrent choking during sleep and daytime hypersomnolence which worsened after gaining weight in the recent year. The arterial blood gas analysis showed she experienced hypoxemia and hypercapnea not only during nighttime but also daytime. We suspected OHS and the patient underwent polysomnography to confirm whether obstructive sleep apnea was present. During the polysomnography test, sleep obstructive apnea was observed and apnea-hypopnea index was 9.2/hr. The patient was treated with bilevel positive airway pressure therapy (BiPAP). After BiPAP for 4 days, hypoxemia and hypercapnia were resolved and she is currently well without BiPAP. We report a case successfully treated with clinical improvement by presuming OHS early in a patient who had typical OHS symptoms, even while having other conditions which could cause hypoventilation.

  • https://doi.org/10.14401/KASMED.2015.22.1.30 인용 PDF KSCI

Analysis of Sports Injuries in Kendo (검도 운동에서 발생된 스포츠 손상의 분석)

  • Song, Hyun-Seok;Park, Sung-Jin;Han, Suk-Ku;Nah, Ki-Ho;Cheung, Hyung-Kook;Choi, Woo-Hyuk;Choi, Nam-Yong
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.4 no.2
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    • pp.122-127
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    • 2005

  • Purpose: To study the mechanism of injuries or discomfort during kendo and to analyze the causes of injury, injured parts of body, treatments modalities, and degree of return to the pre-injury activity level. Materials and Methods: We studied ninety-eight kendo players who had played at three gymnasium of Korean Kumdo Association, were older than high-school age, had been playing kendo for more than six months, and had any pain or discomfort after playing kendo. We analyzed the questionnaire and interviewed the patients concerning the injured parts of body, symptoms, treatments. Results; The mean age was 30.2 years old, and the onset of symptoms was between two weeks and six months after starting the kendo. Many of them were injured during attacking(32.2%). The injuries of feet were increased on players who exercised for less than 1 year. Only fifty-nine players(60.2%) were treated within one month. Among them, thirty-eight percent were treated by oriental medicine or other departments and only thirty-six percent were treated by orthopaedic surgeons. The prevalence of injuries of the foot and ankle was highest(38.8%), and there were the wrist(13.1%), shoulder(11.9%), knee(11.9%) in order of prevalence. Fifty percents of them could return to the pre-injury activity level. Conclusion: The prevalence of injuries of the foot and ankle was highest(38.8%), and were increased on players who exercised for less than 1 year. Sixty percents of players were treated with any proper modalities, and only thirty-six percent were treated by orthopaedic surgeons.

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