• Title/Summary/Keyword: Collapse time

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Surgical outcomes in dogs with tracheal collapse treated with a novel cross-and-hook braided endoluminal stent

  • Uemura, Akiko;Ozai, Yusuke;Hamabe, Lina;Yoshida, Tomohiko;Tanaka, Ryou
    • Journal of Veterinary Science
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    • v.23 no.3
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    • pp.46.1-46.8
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    • 2022
  • Background: Stenting is an effective treatment option for tracheal collapse in dogs. Cross-braided tracheal stents are currently the norm in veterinary medicine, but cross-and-hook braided stents have recently been adopted in human medicine. We examined whether stents manufactured using this novel braiding technique provided additional advantages for the treatment of tracheal collapse in dogs. Objectives: To evaluate the outcomes of cross-and-hook braided stent implantation in the treatment of tracheal collapse in dogs. Methods: The medical records of 22 client-owned dogs that underwent luminal placement of cross-and-hook braided Fauna Stents for the treatment of tracheal collapse between January 2018 and July 2021 were examined and data on canine signalment, clinical signs, diagnostic test results, surgical outcomes, and postoperative complications were retrieved and analyzed statistically. Results: Twenty-six stents were surgically implanted, with 20 dogs (90.9%) receiving one stent and the remaining two (9.1%) receiving two or more stents. All dogs survived the procedure. The median survival time at a median follow-up of 990 days was 879 days. At the final follow-up examination, loss or mild improvement of cough was observed in all dogs. Conclusions: Compared with conventional lumen stents, the cross-and-hook braided Fauna Stent offered a higher survival rate and improved clinical symptoms in all patients. The results of this study suggest that the Fauna Stent may be a promising treatment option for dogs with tracheal collapse.

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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Estimation of the Ultimate Compressive Strength of Actual Ship Panels with Complex Initial Deflection (복잡(複雜)한 형상(形狀)의 초기(初期)처짐을 가진 실선(實船)의 Panel의 압괴강도(壓壞强度) 간이추정법(簡易推定法))

  • Paik, Jeom-K.;Kim, Gun
    • Bulletin of the Society of Naval Architects of Korea
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    • v.25 no.1
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    • pp.33-46
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    • 1988
  • This paper describes a simplified method for estimation of the ultimate compressive strength of actual ship panels with initial deflection of complex shape. The proposed method consists of the elastic analysis using the large deflection theory and the rigid-plastic analysis based on the collapse mechanism which also includes the large deformation effect. In order to reduce the computing time for the elastic large deflection theory and the rigid-plastic analysis based on the collapse mechanism which also includes the large deformation effect. In order to reduce the computing time for the elastic large deflection analysis, only one term of Fourier series for the plate deflection is considered. The results of the proposed method are in good agreement with those calculated by the elasto-plastic large deflection analysis using F.E.M. and the computing time of the proposed method is extremely short compared with that of F.E.M.

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A Study on Behaviour of Tunnel Considering the Location of Groundwater Leaching and Fault Fracture Zone under Tunnel Construction (지하수 용출과 단층파쇄 위치에 따른 터널 거동 연구)

  • Son, Yongmin;Kim, Nagyoung;Min, Kyungjun
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.12
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    • pp.37-43
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    • 2015
  • Ground characteristics is important in tunnel structure utilizing the strength of underground. In the case of the fault fracture zone such as weak soil conditions exists in the tunnel section and groundwater leaching occurs at the same time, it happens to occur to excessive displacement or collapse of tunnel frequently. Fault fracture zone is an important factor that determines the direction of displacement and the collapse of the tunnel under construction. Behavior of fault fracture zone is determined depending on the size and orientation of the surface portion of the tunnel. If the groundwater occurs in the face of tunnel, groundwater causes displacement and collapse. And the collapse characteristics of tunnel is a major factor in determining that the time-dependent behavior. It is difficult to accurately predict groundwater leaching from the fault fracture zone in the numerical analysis method and analyze the interaction behavior of groundwater and fault fracture zone. Therefore numerical analysis method has limitations the analysis of ground water in the ground which the fault fracture zone and groundwater occurs at the same time. It is required to comprehensively predict the behavior of tunnel and case studies of tunnel construction. Thus, the location of fault fracture zone is an important factor that determines the direction of displacement and the collapse of the tunnel. In this study, behavior characteristics of the tunnel according to the location of the fault fracture was analyzed.

Experimental Study of Collapse Delay Effect of Riprap on Dam Slope (사력댐 사석 보호공의 붕괴 지연 효과에 대한 실험 연구)

  • Jeong, Seokil;Kim, Seung Wook;Kim, Hong Taek;Lee, Seung Oh
    • Journal of Korean Society of Disaster and Security
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    • v.11 no.1
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    • pp.31-38
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    • 2018
  • The 99.1% of small dam and most of the levees in Korea are soil dam which can be constructed with lower cost and less effort compared with ones made of concrete. However, they are so vulnerable to overflow. Sudden collapses of these strucrues lead to increase flow rate rapidly, which may cause catastrophic problems in downstream regions. In this study, the experimental study on the collapse delay effect of riprap that was laid on slope of soil levee was carried out. A prismatic rectangular open channel was used and three different sizes of the riprap were installed on slope of a scaled earth dam. A new formula for the collapse time of the levee with the installation of riprap was presented, using the previous researches and the dimensional analysis. In this process, an unsteady flow condition was considered to derive the deviation time of the riprap. And additional experiments were conducted to understand the effect of reinforcement of riprap, and it was found that the reinforcement of riprap was more effective than twice sizing of intial riprap. If the collapse time is delayed, EAP (Emergency Action Plan) and forecasting can greatly reduce the degree of flood damage. Also, it will be meaningful that the results of this study are used for river design.

Visualization of the Water Column Collapse by using SMAC Method (SMAC법을 이용한 물기등 붕괴의 가시화)

  • Kim, Nam-Hyeong;Kim, Nam-Guk
    • Journal of Korea Water Resources Association
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    • v.34 no.6
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    • pp.605-615
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    • 2001
  • SMAC method, one of the numerical simulation techniques, is modified from the original MAC method for the time-dependent variation of fluid flows. The Navier-Stokes equations for incompressible time-dependent viscous flow is applied, and marker particles which present the visualization of fluid flaws are used. In this study, two-dimensional numerical simulations of the water column collapse are carried out by SMAC method, and the simulation results are compared with Martin and Moyce's experimental data and result of the MPS method. A good results are obtained. This numerical simulation could also be applied to the breaking phenomenon of hydraulic structures such as dam break.

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Application of new external total ring prostheses made by drip chamber of intravenous administration set in normal dogs (정상 견에서 수액세트 점적통을 이용한 새로운 기관 외부 보철링의 적용)

  • Jeong, Sang-hyi;Jeong, Soon-wuk
    • Korean Journal of Veterinary Research
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    • v.44 no.1
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    • pp.137-141
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    • 2004
  • The purpose of this study was to compare easiness of application of polypropylene external total ring prosthesis (PPTRP, Group A) with that of polyvinylchloride external total ring prosthesis (PVCTRP, Group B), which were used for surgical correction of tracheal collapse in dogs. PPTRP was made from 3 ml syringe and PVCTRP from the drip chamber of intravenous administration set. Prostheses of group A (n=5) and B (n=5) were placed to cervical trachea in clinically normal 10 dogs, respectively weighing between 4 kg and 6 kg. There were mild coughing and swelling in one to three dogs of both groups for 3 days after surgery. No exercise intolerance was observed in both groups after surgery. There were no different results of clinical signs and radiographic views after surgery between group A and group B. The time (mean${\pm}$SD) to make total ring prosthesis, group A took $23.2{\pm}1.9$ minutes which was remarkably longer than that $(4.6{\pm}0.3)$ of group B. Also, the time to place around trachea, group A required $61.8{\pm}8.8$ minutes and group B $38.4{\pm}8.0$ minutes. Conclusionly, PVCTRP was timesaving and easier to make, fix, and suture than those of PPTRP. PVCTRP may be used alternatively to PPTRP for the tracheal collapse to treat in dogs.

An Adaptive Undervoltage Load Shedding Against Voltage Collapse Based Power Transfer Stability Index

  • Nizam, Muhammad;Mohamed, Azah;Hussain, Aini
    • Journal of Electrical Engineering and Technology
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    • v.2 no.4
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    • pp.420-427
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    • 2007
  • This paper highlights the comparison of a proposed methods named adaptive undervoltage load shedding based PTSI techniques for undervoltage load shedding and two previous methods named Fixed Shed Fixed Delay (FSFD) and Variable Shed Variable Delay (VSVD) for avoiding voltage collapse. There are three main area considerations in load shedding schemes as the amount of load to be shed, the timing of load shedding event, and the location where load shed is to be shed. The proposed method, named as adaptive UVLS based PTSI seem to be most appropriate among the uncoordinated schemes. From the simulation result can be shown the Adaptive UVLS based PTSI give faster response, accurate and very sensitive control for the UVLS control technique. This technique is effectively when calculating the amount to be shed. Therefore, it is possible to bring the voltage to the threshold value in one step. Thus, the adaptive load shedding can effectively reduce the computational time for control strategy.

Application of shakedown analysis technique to earthquake-resistant design of ductile moment-resisting steel structures

  • Lee, Han-Seon;Bertero, Vitelmo V.
    • Structural Engineering and Mechanics
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    • v.1 no.1
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    • pp.31-46
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    • 1993
  • The motivations of the application of shakedown analysis to the earthquake-resistant design of ductile moment-resisting steel structures are presented. The problems which must be solved with this application are also addressed. The illustrative results from a series of static and time history nonlinear analyses of one-bay three-story steel frame and the related discussions have shown that the incremental collapse may be the critical design criterion in case of earthquake loading. Based on the findings, it was concluded that the inelastic excursion mechanism for alternation load pattern, such as in earthquake, should be the sidesway mechanism of the whole structure for the efficient mobilization of the structural energy dissipating capacity and that the shakedown analysis technique can be used as a tool to ensure this mechanism.

Influence of Stacking Condition on Collision Safety of CFRP Side Member (적층구성이 CFRP 사이드 부재의 충돌안전성에 미치는 영향)

  • Hwang, Woo Chae;Yang, In Young
    • Journal of the Korean Society of Safety
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    • v.29 no.3
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    • pp.14-19
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    • 2014
  • The global demand for reduction in the weight of automobiles has led many countries to focus on the development of hybrid, eco-friendly, and electric cars. Reduction in the weight of materials can both increase fuel efficiency and maximize automobile performance. Therefore, the design of automobile should be inclined towards the safety aspects. but at the same time, it also consider reducing the structural weight of an automobile. In this study, CFRP side members with circular and double hat shaped section was manufactured. The impact collapse tests performed with change of the stacking condition, such as variation of interface number and outerlayer angle. The impact collapse load and absorbed energy were quantitatively analyzed according to the changes in section shapes and stacking condition. This analysis was performed to obtain design data that can be applied in the development of optimum lightweight members for automobiles.