• Journal of Chest Surgery
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• v.27 no.5
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• pp.418-421
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• 1994

The usage of autosuture instruments and techniques in resection of bronchovascular structures gained increasing acceptance amongst surgeons in the recent years. The manipulation of these devices are simple, safe, and shortens operating time by avoiding numerous ties and sutures. We have been using autosuture instruments in most of pulmonary resections in Yongdong Severance hospital, and had a satisfactory results. However, we recently have experienced post-pneumonectomy rupture of left pulmonary vein on postoperative one day where the rupture site was in the border of left atrium and left pulmonary vein where the stapler was fired. The patient underwent emergency operation to control massive bleeding and successfully managed by left atrial suture.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.8 no.1
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• pp.26-30
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• 2015

There are many traumatic foot and ankle problems in orthopaedic fields. Though it is not life-threatening problems, a delay in accurate diagnosis and treatments can danger limb function and therefore correct diagnosis can prevent long-term complications. Achilles tendon rupture is relatively common injury for active sports people. Ultrasonography is cost-effective, irradiation -free, effective for evaluation of soft tissues and dynamic analysis. It has been growing importance in Achilles tendon rupture. Ultrasonography is a diagnostic tool in Achilles tendon rupture. Physical examination and patient history is needed to diagnose Achilles tendon without image, but it is missed up by 20% in private clinic. Discontinuity of normal fibrillar architecture seen on an ultrasonographic image is diagnostic for Achilles tendon rupture, and can be accentuated by the performance of dorsi-flexion and plantar flexion, while observing in real time. And ultrasonography is a reliable method for serial observation after surgical treatment or conservative treatment.

• Journal of Ocean Engineering and Technology
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• v.35 no.6
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• pp.426-433
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• 2021

In this study, three types of synthetic fiber materials were evaluated, namely, DM20, SK78, and T147, to replace steel chains in shipbuilding and offshore fields with fiber chains as there is increasing demand for chains with lighter weights and improved usabilities. The strength and quasi-static stiffness were analyzed to select suitable yarns for the fiber chains. The durability of the yarn was evaluated by performing a 3-T (time to rupture) test as a specific tension level. The results of the experiment revealed excellent dynamic stiffness in DM20 and highest values of the windward and leeward stiffness in T147. 3-T linear design characteristic curves for a specific tension level were derived for the three types of fiber materials. The findings of this study can provide insights for improving strength and durability in fiber chain design.

• Journal of Veterinary Clinics
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• v.20 no.2
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• pp.229-232
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• 2003

Ultrasonographic examination of the stifle joint four clinically and radiographically normal adult dogs was performed before and after inducing the cranial cruciate ligament (CrCL) rupture of the bilateral stifle surgically. At Pre- or post-surgery, the hyperechoic patella ligament and the echogenic infrapatella fat interfered the visualization of the CrCL by the plain scanning method. However when the stifle joint was imaged by the scanning method injecting normal saline within the joint capsule, the hyperechogenic ligament was visualized by the separation of the infrapatella fat and the CrCL and the contrast effect of anechoic saline. When the stifle joint was imaged by the real time scanning method after the induction of the surgical rupture, fluttering of the ligament and anechoic area between the bone and the CrCL was identified due to the lack of tonicity and continuity of the ligament. Enlargement of the ligament because of its increased diameter as well as fluttering of the CrCL and the increased joint space's thickness was visualized. Consequently, confirming fluttering of the CrCL, increased ligament diameter and anechoic region between the CrCL and the bone, ultrasonographic examination is a valuable diagnostic tool as well as cranial drawer test and radiographic examination.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.79-89
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• 2004

An elastic-plastic-viscous constitutive model was proposed based on a simple formulation scheme. The anisotropic modified Cam-Clay model was extended for the general stress space for the plastic simulation. The generalized viscous theory was simplified and used for the viscous constitutive part. A damage law was incoporated into the proposed constitutive model. The mathematical formulation and development of the model were performed from the point of view that fewer parameters be better employed. The creep behaviors with or without creep rupture were predicted using the developed model for cohesive soils. The model predictions were favorably compared with the experimental results including the undrained creep rupture, which is an important observed phenomenon for cohesive soils. Despite the simplicity of the constitutive model, it performs well as long as the time to failure ratio of the creep rupture tests is within the same order of magnitude.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.3
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• pp.84-91
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• 2012

This paper aims to investigate the effects of cable rupture on the dynamic responses of concrete cable-stayed bridges in comparison with those of steel composite ones. It examines an adequate analysis method for simulating cable rupture using a time history function and evaluates the design guidelines for dynamic amplification factor (DAF). The computed DAFs from a concrete cable-stayed bridge are compared with those from a steel composite one based on the design guideline. As a conclusion, the current design guidelines for DAF may be reliable in overall but show some unstable cases despite satisfying the design guidelines, especially for concrete cable-stayed bridges.

• Journal of Power System Engineering
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• v.4 no.1
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• pp.74-80
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• 2000

This present study was investigated effect of Ni contents on the high temperature strength characteristic in 9Cr ferritic heat-resistant steel added 1.7%W in place of Mo in order to restraint laves phase formation. Precipitation amount of carbide, number of particle per unit area and particle size of carbide were decreased with increase of Ni content. In the steels, carbides of $M_{23}C_6$ type was mainly precipitated, but laves phases could not precipitated. Tensile and yield strength, creep strength and creep rupture time was decreased, but elongation were increased due to decreasing of particle number per unite area and carbide amount precipitated with increase of Ni content.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.228-233
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• 2004

The characteristics of the probability distribution for mechanical properties, e.g. tensile strength, reduction of area ana elongation, for STS304 stainless steel in elevated temperature were investigated from tensile test performed by constant cross head speea controls with 1mm/min, Recently, in order to clarify the strengthening mechanisms at high temperature, a new scheme to improve high temperature mechanical properties is desired. Therefore, the test ,technique development of high temperature creep behaviors for this material is very important. In this paper, the creep praperties and creep life prediction by Larson-Miller parameter method for STS304 stainless steel to be used for other high temperature components were presented at the elevated temperatures of 600, 650 and $700^{\circ}C$.

• Journal of Power System Engineering
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• v.6 no.1
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• pp.55-60
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• 2002

There has been no report on the life prediction for gas turbine materials at high temperatures based on the creep properties and their relationship with the AE(acoustic emission) properties as a means of real-time non-destructive testing. One of the important issues is thus to develop a reliable method of evaluating creep properties by the AE technique. In this paper, the real-time evaluation of high temperature creep time and AE cumulative counts for nickel-based superalloy Udimet 720 was performed on round-bar type specimens under pure load at the temperatures of 811, 922 and 977K. The total AE cumulative counts until the starting point of secondary creep($N_1$) and that of tertiary creep($N_2$) have quantitative relationship with the tertiary creep time and the rupture time. It is thus possible to construct the life prediction system based on creep and the prevention system of tertiary creep by using AE technique.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.4
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• pp.366-372
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• 2009

Creep life prediction has been commonly used by a time-temperature parameter (TTP) which is correlated to an applied stress and temperature, such as Larson-Miller (LM), Orr-Sherby-Dorn (OSD), Manson-Haferd (MH) and Manson-Succop (MS) parameters. A stress-temperature linear model (STLM) based on Arrhenius, Dorn and Monkman-Grant equations was newly proposed through a mathematical procedure. For this model, the logarithm time to rupture was linearly dependent on both an applied stress and temperature. The model parameters were properly determined by using a technique of maximum likelihood estimation of a statistical method, and this model was applied to the creep data of Alloy 617. From the results, it is found that the STLM results showed better agreement than the Eno’s model and the LM parameter ones. Especially, the STLM revealed a good estimation in predicting the long-term creep life of Alloy 617.