• Title/Summary/Keyword: Mechanical Failure

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Clinical experience of ventilator therapy in chest trauma (인공호흡기 치료를 받은 흉부외상 환자의 임상적 고찰)

  • 서강석
    • Journal of Chest Surgery
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    • v.26 no.1
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    • pp.59-63
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    • 1993
  • A clinical evaluation was performed with a population of 49 patients of chest trauma, who were diagnosed to undergo ventilator therapy, and had gone through ventilator therapy at the Department of Thoracic and Cardiovascular Surgery, Kyungpook University Hospital. One of most common causes of chest trauma was vehicle accidents [77.5%] with the prevalent age group being their forties. The common findings were multiple rib fractures [89.8%], hemopneumothrax [81.6%], lung contusion [61.2%] and flail chest [44.9%]. Their common combined injuries were the orthopedics and neurosugical injuries [86.7%]. Complications caused by chest trauma were pneumonia, respiratory failure, atelectasis, barotrauma and empyema. Pulmonary infections were commonly associated with mechanical ventilation in the long term group and were best prevented by using bronchial hygiene therapy.The mortality rate was 5.8% of the total patients and that was 38.8% of the patients, who needed ventilator therapy. The causes of death were pneumonia, respiratory failure, acute renal failure and hypovolemic shock. Mechanical ventilation has an important place in the treatment of patients with severe chest trauma.

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A method and analysis of human-error management of a semiconductor industry (반도체산업에서의 인적오류제어방법 및 연구)

  • Yoon Yong-Gu;Park Peom
    • Journal of the Korea Safety Management & Science
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    • v.8 no.1
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    • pp.17-26
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    • 2006
  • Basis frame-work's base in a semiconductor industry have gas, chemical, electricity and various facilities in bring to it. That it is a foundation by fire, power failure, blast, spill of toxicant huge by large size accident human and physical loss and damage because it can bring this efficient, connect with each kind mechanical, physical thing to prevent usefully need that control finding achievement factor of human factor of human action. Large size accident in a semiconductor industry to machine and human and it is involved that present, in system by safety interlock defect of machine is conclusion for error of behaviour. What is not construing in this study, do safety in a semiconductor industry to do improvement. Control human error analyzes in human control with and considers mechanical element and several elements. Also, apply achievement factor using O'conner Model by control method of human error. In analyze by failure mode effect using actuality example.

A study on nonlinear analysis and confinement effect of reinforced concrete filled steel tubular column

  • Xiamuxi, Alifujiang;Hasegawa, Akira;Yu, Jiang
    • Structural Engineering and Mechanics
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    • v.56 no.5
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    • pp.727-743
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    • 2015
  • According to former studies, the mechanical properties of reinforced concrete filled tubular steel (RCFT) columns differed greatly from that of concrete filled steel tubular (CFT) columns because of interaction of inserted reinforcement in RCFT. Employing an experiment-based verification policy, a general FE nonlinear analysis model was developed to analyze the mechanical behavior and failure mechanism of RCFT columns under uniaxial compression. The reasonable stress-strain relationships were suggested for confined concrete, reinforcements and steel tube in the model. The mechanism for shear failure of concrete core was found out in the numerical simulation, and a none-conventional method and equation for evaluating the confinement effect of RCFT were proposed.

Unusual Roentgenographic Presentation of Lung Cancer in a Pregnant Woman with Acute Respiratory Failure (급성 호흡부전 임산부에서의 폐병변)

  • Park, Tae-Byung;Hwang, Sung-Chul;Lee, Yi-Hyeong;Park, Kyung-Joo;Joo, Hee-Jae
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.6
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    • pp.951-954
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    • 1995
  • Diagnostic procedures in pregnant wowen is limited and is usually delayed, especially so if she is on mechanical ventilation. A 28-year-old pregnant woman with severe dyspnea was referred to our hospital under the impression of miliary tuberculosis. The respiratory failure was so severe that patient had to be managed with mechanical ventilator under clinical impression of overwhelming pneumonia or pulmonary tuberculosis. But the patient's conditions deteriorated. Bronchoscopy and blind transbronchial lung biopsy performed to determine the nature of the etiology, and to our surprise, revealed squamous cell carcinoma of the lung.

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Analysis of the shear failure process of masonry by means of a meso-scopic mechanical modeling approach

  • Wang, Shuhong;Tang, Chun'an;Jia, Peng
    • Structural Engineering and Mechanics
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    • v.24 no.2
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    • pp.181-194
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    • 2006
  • The masonry is a complex heterogeneous material and its shear deformation and fracture is associated with very complicated progressive failures in masonry structure, and is investigated in this paper using a mesoscopic mechanical modelling, Considering the heterogeneity of masonry material, based on the damage mechanics and elastic-brittle theory, the newly developed Material Failure Process Analysis (MFPA) system was brought out to simulate the cracking process of masonry, which was considered as a three-phase composite of the block phase, the mortar phase and the block-mortar interfaces. The crack propagation processes simulated with this model shows good agreement with those of experimental observations by other researchers. This finding indicates that the shear fracture of masonry observed at the macroscopic level is predominantly caused by tensile damage at the mesoscopic level. Some brittle materials are so weak in tension relative to shear that tensile rather than shear fractures are generated in pure shear loading.

An Experimental Study to Prevent Debonding Failure of RC Beams Strengthened with Near Surface Mounted CFRP (표면매립공법으로 휨보강된 RC보의 부착파괴 방지 상세에 대한 실험연구)

  • Jung, Woo-Tai;Park, Jong-Sup;You, Young-Jun;Park, Young-Hwan;Kang, Jae-Yoon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.469-472
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    • 2004
  • This paper presents test results to prevent debonding failure of reinforced concrete beams strengthened with near-surface mounted(NSM) CFRP. Beams strengthened with different strengthening systems with externally bonded CFRP, NSM CFRP and NSM CFRP with mechanical interlocking. Test results indicated that using NSM CFRP is improved the stiffness and increased the flexural capacity of RC beams and NSM CFRP with mechanical interlocking prevented debonding failure of RC beams.

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Duromedics Mitral Valve Leaflet Escape (Duromedics 승모판막의 판엽파손)

  • 나찬영
    • Journal of Chest Surgery
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    • v.25 no.7
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    • pp.750-755
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    • 1992
  • We report a case of leaflet embolization of central leaflet fracture a 31mm mitral Edw-ards-Duromedics prosthesis. A leaflet was fractured to two segments, a larger one embolized to right common iliac artery and a smaller one to left femoral artery, respectively. Patient was reoperated with 29mm mitral Carbomedics prosthesis and incidentally found of smaller segment in left femoral artery at cannulation site. The embolectomy was done 15 days after cardiac operation through midline abdominal incision, Leaflet escape of a mitral Edward-Duromedics prosthesis is a rare, potentially curable mode of valve failure. After mechanical valve replacement, unexplained heart failure and acute pulmonary edema, mechanical valve failure should be suspected. Correct interpretation of clinical signs, symptoms and fluroscopy should allow early diagnosis of leaflet escape and prompt surgical therapy.

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Failure-Proof Design of the PCB of a Monitor Using Deformed Mode Shape (변형 모드를 이용한 모니터용 회로 기판의 파손 저감 설계에 관한 연구)

  • Park, Sang-Hu;Lee, Bu-Yun
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.1
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    • pp.111-116
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    • 2001
  • A practical scheme to reduce failure of the PCB(Printed Circuit Board) of a monitor is introduced using deformed mode shape under mechanical shock. When the monitor is given critical shock loads, cracks are commonly initiated at the tip of a hole on the PCB. Accordingly, a deformed mode shape of the PCB is obtained using a FEM code to define a weak point on the PCB under mechanical shock, and then the position and direction of the hole is determined to prevent the failure at the critical mode shape. Also, the stress intensity factor around the weak point on the PCB is calculated to check the possibility of fracture by normal tensile stress. In conclusion, present research is useful to assist the practical design of components-layout on the PCB.

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Development of gear fault diagnosis architecture for combat aircraft engine

  • Rajdeep De;S.K. Panigrahi
    • Advances in Computational Design
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    • v.8 no.3
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    • pp.255-271
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    • 2023
  • The gear drive of a combat aircraft engine is responsible for power transmission to the different accessories necessary for the engine's operation. Incorrect power transmission can occur due to the presence of failure modes in the gears like bending fatigue, pitting, adhesive wear, scuffing, abrasive wear and polished wear etc. Fault diagnosis of the gear drive is necessary to get an early indication of failure of the gears. The present research is to develop an algorithm using different vibration signal processing techniques on industrial vibration acquisition systems to establish gear fault diagnosis architecture. The signal processing techniques have been used to extract various feature vectors in the development of the fault diagnosis architecture. An open-source dataset of other gear fault conditions is used to validate the developed architecture. The results is a basis for development of artificial intelligence based expert systems for gear fault diagnosis of a combat aircraft engine.

Simulation of the tensile failure behaviour of transversally bedding layers using PFC2D

  • Haeri, Hadi;Sarfarazi, Vahab;Zhu, Zheming;Marji, Mohammad Fatehi
    • Structural Engineering and Mechanics
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    • v.67 no.5
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    • pp.493-504
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    • 2018
  • In this paper, the tensile failure behaviour of transversally bedding layers was numerically simulated by using particle flow code in two dimensions. Firstly, numerical model was calibrated by uniaxial, Brazilian and triaxial experimental results to ensure the conformity of the simulated numerical model's response. Secondly, 21 circular models with diameter of 54 mm were built. Each model contains two transversely bedding layers. The first bedding layer has low mechanical properties, less than mechanical properties of intact material, and second bedding layer has high mechanical properties, more than mechanical properties of intact material. The angle of first bedding layer, with weak mechanical properties, related to loading direction was $0^{\circ}$, $15^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, $75^{\circ}$ and $90^{\circ}$ while the angle of second layer, with high mechanical properties, related to loading direction was $90^{\circ}$, $105^{\circ}$, $120^{\circ}$, $135^{\circ}$, $150^{\circ}$, $160^{\circ}$ and $180^{\circ}$. Is to be note that the angle between bedding layer was $90^{\circ}$ in all bedding configurations. Also, three different pairs of the thickness was chosen in models; i.e., 5 mm/10 mm, 10 mm/10 mm and 20 mm/10 mm. The result shows that In all configurations, shear cracks develop between the weaker bedding layers. Shear cracks angel related to normal load change from $0^{\circ}$ to $90^{\circ}$ with increment of $15^{\circ}$. Numbers of shear cracks are constant by increasing the bedding thickness. It's to be note that in some configuration, tensile cracks develop through the intact area of material model. There is not any failure in direction of bedding plane interface with higher strength.