• Title/Summary/Keyword: failure site

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Methodology of seismic-response-correlation-coefficient calculation for seismic probabilistic safety assessment of multi-unit nuclear power plants

  • Eem, Seunghyun;Choi, In-Kil;Yang, Beomjoo;Kwag, Shinyoung
    • Nuclear Engineering and Technology
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    • v.53 no.3
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    • pp.967-973
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    • 2021
  • In 2011, an earthquake and subsequent tsunami hit the Fukushima Daiichi Nuclear Power Plant, causing simultaneous accidents in several reactors. This accident shows us that if there are several reactors on site, the seismic risk to multiple units is important to consider, in addition to that to single units in isolation. When a seismic event occurs, a seismic-failure correlation exists between the nuclear power plant's structures, systems, and components (SSCs) due to their seismic-response and seismic-capacity correlations. Therefore, it is necessary to evaluate the multi-unit seismic risk by considering the SSCs' seismic-failure-correlation effect. In this study, a methodology is proposed to obtain the seismic-response-correlation coefficient between SSCs to calculate the risk to multi-unit facilities. This coefficient is calculated from a probabilistic multi-unit seismic-response analysis. The seismic-response and seismic-failure-correlation coefficients of the emergency diesel generators installed within the units are successfully derived via the proposed method. In addition, the distribution of the seismic-response-correlation coefficient was observed as a function of the distance between SSCs of various dynamic characteristics. It is demonstrated that the proposed methodology can reasonably derive the seismic-response-correlation coefficient between SSCs, which is the input data for multi-unit seismic probabilistic safety assessment.

End-of-Life Care for End-stage Heart Failure Patients

  • Ju-Hee Lee;Kyung-Kuk Hwang
    • Korean Circulation Journal
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    • v.52 no.9
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    • pp.659-679
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    • 2022
  • Efforts to improve end-of-life (EOL) care have generally been focused on cancer patients, but high-quality EOL care is also important for patients with other serious medical illnesses including heart failure (HF). Recent HF guidelines offer more clinical considerations for palliative care including EOL care than ever before. Because HF patients can experience rapid, unexpected clinical deterioration or sudden death throughout the disease trajectory, choosing an appropriate time to discuss issues such as advance directives or hospice can be challenging in real clinical situations. Therefore, EOL issues should be discussed early. Conversations are important for understanding patient and family expectations and developing mutually agreed goals of care. In particular, high-quality communication with patient and family through a multidisciplinary team is necessary to define patient-centered goals of care and establish treatment based on goals. Control of symptoms such as dyspnea, pain, anxiety/depression, fatigue, nausea, anorexia, and altered mental status throughout the dying process is an important issue that is often overlooked. When quality-of-life outweighs expanding quantity-of-life, the transition to EOL care should be considered. Advanced care planning including resuscitation (i.e., do-not resuscitate order), device deactivation, site for last days and bereavement support for the family should focus on ensuring a good death and be reviewed regularly. It is essential to ensure that treatment for all HF patients incorporates discussions about the overall goals of care and individual patient preferences at both the EOL and sudden changes in health status. In this review, we focus on EOL care for end-stage HF patients.

Estimation of Shear Plane at Failed Landfill Using Field and Laboratory Tests (현장 및 실내실험을 이용한 매립지 전단활동면 추정에 대한 연구)

  • Choi, Hoseong;Kim, Tae-Hyung;Kim, Sung-Wook
    • The Journal of Engineering Geology
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    • v.29 no.3
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    • pp.315-327
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    • 2019
  • Back analysis has been used to evaluate the factor of safety and circular failure plane at the landfill failure site. However, the estimated circular failure plane by back analysis is quite different from what is observed in the field. Thus, this study was conducted to estimate an actual shear failure plane inside the ground which gives a more accurate failure plane. Cone penetration test (CPT), boring test, soft X-ray image scan, density logging, and ultrasonic logging were conducted at the field and laboratory. The result of CPT showed significantly lower cone resistance, pore pressure, and undrained shear strength at a particular part. This part is a possible shear failure plane inside the ground. To validate, the soft X-ray scan images were analyzed and found the disturbed (inclined) bedding plane induced by shear activity at the estimated shear failure plane. Density and ultrasonic logging tests also found a similar result. Thus, the method in this study is possible to estimate the shear failure plane inside the ground.

Analysis of Tunnel Behavior Using Progressive Rockmass Failure Technique (암반의 진행성 파괴 기법을 이용한 터널거동 분석)

  • 이성민;이윤규;신성렬
    • Tunnel and Underground Space
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    • v.9 no.4
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    • pp.288-295
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    • 1999
  • Concentrated stresses due to the underground tunnel excavation easily cause many problems such as yielding, popping, and failure at the immediate roof, wall and floor of tunnel. Therefore, it is very important to predict the possibility of these problems when a tunnel is excavated underground. There are two typical methods to predict these problems. The one is to predict problems from the analysis of field monitoring data and the other is to predict them from computer simulations using good site investment data. Using the second method, this study attempted to describe the time-dependent or progressive manner of immediate roof and wall due to the underground tunnel excavation. An iterative technique was used to represent progressive failure of rockmass with the Hoek and Brown theory. By developing and simulating three different shapes of twin tunnels, this research estimated the proper size of critical pillar width between tunnels, distributed stresses on the tunnel walls, and convergences of tunnel crowns. Moreover, results out of progressive failure technique based on the Hoek and Brown theory were compared with the results out of Mohr-Coulomb theory.

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Pitfalls, Complications, and Necessity of Education about REBOA: A Single Regional Trauma Center Study

  • Kim, Sol;Chung, Jae Sik;Jang, Sung Woo;Jung, Pil Young
    • Journal of Trauma and Injury
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    • v.33 no.3
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    • pp.153-161
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    • 2020
  • Purpose: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emergency procedure and extremely time-dependent, and the proficiency of the physician is important. Due to a lack of REBOA education programs in Republic of Korea, few physicians have been trained in the procedure. In this study, we examined how REBOA education affects clinical outcomes in a single center. Methods: A retrospective study conducted from February 2017 to June 2020 at a regional trauma center. We collected data of patients who underwent REBOA and analyzed the factors that influenced the outcome. The patients were divided into the educated and non-educated groups (based on REBOA training received by their physicians), and the success and failure groups. Results: A total of 24 patients underwent REBOA during the study. There were eight patients in the success group and 16 patients in the failure group. There are no significant differences between the educated and non-educated groups in sex, age, ISS, shock, injury-to-REBOA time, injury mechanism, injury sites, arrest, access site, type of catheter, type of REBOA, target Zone, mortality, and the result of REBOA. The non-educated group had a higher risk for failure compared to the educated group in multivariate analysis (odds ratio [OR] 154.64, 95% confidence interval [CI] 1.11-22.60). Conclusions: Failure in REBOA is harmful to patients. The risk of failure is increased in the non-educated group. Physicians working in the trauma center or emergency department need to complete the REBOA education program.

Radiation Therapy Result of Polymorphic Reticulosis (다형성 세망증(Polymorphic Reticulosis)의 방사선 치료 성적)

  • Chung, Eun-Ji;Kim, Gwi-Eon;Park, Young-Nyun
    • Radiation Oncology Journal
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    • v.11 no.1
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    • pp.83-90
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    • 1993
  • During the period from January, 1975, to June, 1989, one hundred patients with histopathologically proven polymorphic reticulosis in the upper respiratory tract were treated with radiation therapy and the analysis of treatmemt results was undertaken. One hundred patients (69 males, 31 females) with a mean age of 46 years (range 12-79 years) were presented. Nasal cavity was the most frequent site of involvement ($56{\%}$), and 44 cases had multifocal sites of involvement. The incidence of cervical lymph node metastasis at initial diagnosis was $24{\%}$. Staging was determined by Ann-Arbor classification, retrospectively. The number of patients of stage IE, IIE, IIIE and IVE were 35, 60, 1, and 4, respectively. The overall 5 year actuarial survival rates were $38.4{\%}$. The difference in 5 year survival rates between patients with stage IE and IIE, with solitary and multiple, with CR and PR after irradiation were significant statistically. For the analysis of failure patterns, failure sites include the following: local failure alone (30/55=$54.6{\%}$), systemic failure alone (9/55=$16.4{\%}$), both local and systemic failure (16/55=$29.0{\%}$). Retrograde slide review was available in 29 cases of PMR with respect to histopathologic bases, and immunohistochemical studies were performed using MT1 and DACO-UCHL-1 as T-cell markers, MB2 as a B-cell marker and alpha-1-antichymotrypsin as a histiocytic markers. All that 29 cases showed characteristic histologic features similar to those of peripheral T-cell lymphoma and showed positive reactio to the T-cell marker. These findings suggest strongly that quite a significant portion of PMR may be in fact T-cell lymphoma.

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No Collapse Design for Typical Bridges (일반교량의 붕괴방지설계)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.3
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    • pp.163-172
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    • 2014
  • The purpose of earthquake resistant design for typical bridges is the No Collapse Design and the Earthquake Resistant Design Part of Roadway Bridge Design Code provides a design process to construct the Ductile Failure Mechanism for the bridge structure. However, if it is not practical to provide the Ductile Failure Mechanism due to structure types or site conditions, the Brittle Failure Mechanism is an alternative way to get the No Collapse Design. As well as the existing design process constructing the Ductile Failure Mechanism, the Earthquake Resistant Design Part provides a ductility-based design process as an appendix, which is prepared for bridges with reinforced concrete piers. According to the new design process, designer determines a required response modification factor for substructure and transverse reinforcement for confinement therefrom. In this study, a typical bridge with steel bearing connections and reinforced concrete piers is selected for which the existing as well as the ductility-based design processes are applied and different results from the two design processes are identified. Based on the results, an earthquake resistant design procedure is proposed in which designers should consider the two design processes.

A Study on the Improvement of Fire Safety in high-rise Building Construction in Legal aspects (법규적 측면에서 고찰한 고층 건축물 공사현장 화재안전 확보방안)

  • Park, Chan-Seok;Jeong, Il-Kyun
    • Journal of the Korea Safety Management & Science
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    • v.17 no.1
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    • pp.21-32
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    • 2015
  • High rising of the buildings offers a number of risk factors than ever before with regard to fire prevention. Especially in the construction site of high-rise buildings, people waste golden-time during the evacuation because temporary fire fighting facilities are not installed and transferred to a large fire because of fire suppression failure. In this study, the researcher derives the problems of fire protection in high-rise buildings construction sites and proposed the measures in such the legal aspects as fire building construction code and etc. There are the legal improvements such as orders of construction suspension in the problems of fire safety, appointing fire safety manager, temporary fire protection installation standards, enhancing penalty provisions regarding the use of fire, operating self fire brigade, confirming on-site after completing fire-protection facalities, establishment or strengthening special fire-protection investigations.

Surgical Treatment of Tracheal Stenosis -Report of 3 Cases- (기관협착증 치험 3례)

  • Park, Cheol-Ho;U, Jong-Su;Jo, Gwang-Hyeon
    • Journal of Chest Surgery
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    • v.21 no.2
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    • pp.395-402
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    • 1988
  • Increasing success in the management of patients with severe respiratory failure by mechanical respirators has produced iatrogenic tracheal stenosis. And the surgical management of these lesions have provided a major field for tracheal reconstructive surgery. Recently we have experienced three cases of postintubation tracheal stenosis between December, 1985 and October, 1987 and successfully performed circumferential resection and end to end anastomosis of the trachea. The lesion of the first case which was located in the subcricoid level was resected about 2cm length with cervical incision. And the lesion of the second case located at the cuff site was also resected about 2.5cm length with cervical and median sternotomy incision. Also the lesion of the third case located at the stoma site was resected about 1.8cm length with cervical incision. The postoperative courses were uneventful but there was extubation difficulty in the third case because of stupor mentality and problem of secretion excretion. So we have observed the postoperative course after T-tube insertion.

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Clinical Evaluation of Traumatic Diaphragmatic Injuries (외상성 횡격막 손상에 대한 임상적 고찰)

  • Seo, Seong-Gu;Gwon, O-Chun;Lee, Gil-No
    • Journal of Chest Surgery
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    • v.27 no.12
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    • pp.1023-1026
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    • 1994
  • We reviewed 10 cases of traumatic diaphragmatic injuries at Soonchunhyang University Gumi Hospital from January 1990 through April 1993. seven patients were male and three patients were female. The age distribution was ranged from 25 to 79 years, predominant 4th decades occurred in male. The traumatic diaphragmatic injuries were due to blunt trauma in 9 cases (traffic accident 7 and crash injury 2) and penetrating wound in 1 case (stab wound). The common symptom were dyspnea (60%), chest pain and abdominal pain in order frequency. In the blunt trauma and crash injury, te rupture site was all located in the left(9 cases). In the penetrating wound, the rupture site was located in the right(1 case). The surgical repair of 10 cases were performed with transthoracic approach in 9 cases and thoracoabodominal approach in 1 case. The postoperative mortality was 10% (1/10). The cause of death was multiple organ failure with pulmonary edema.

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