• Journal of Welding and Joining
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• v.19 no.1
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• pp.82-87
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• 2001

The creep-rupture and low cycle fatigue properties of transient liquid phase bonded joints of Ni-base single crystal superalloy, CMSX-2 was investigated using MBF-80 insert metal. The (100) orientation of bonded specimen was aligned perpendicular to the joint interface. CMSX-2 was bonded at 1523K for 1.8ks in vacuum, optimum bonding condition. The creep rupture strength and rupture lives of the joints were the almost identical to ones of the base metal. SEM observation of the fracture surfaces of joints after creep rupture test revealed that the fracture surfaces classified three types of region, ductile fracture surface, cleavage fracture surface and interfacial fracture surface. The low cycle fatigue properties of the joints were also the same level as those of base metal. The elongation and reduction of area values of joints were comparable to those of base metal while fell down on creep rupture condition of high temperature.

• Journal of Chest Surgery
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• v.8 no.1
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• pp.19-28
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• 1975

The thoracoscopic study was reported on 21 cases of spontaneous pneumothorax requiring surgical management, and clinical values of thoracoscopic examination on spontaneous pneumothorax were also discussed. patients were treated in the Department of .Thoracic Surgery, Hanyang University Hospital for the period of two Years from May 1972 to April 1974. For exact detection of etiologic factors on spontaneous pneumothorax, the thoracoscopic examination in the intrapleural space was performed in parallel with X-ray study. this study, the difference of diagnostic and therapeutic significance between radiological and thoracoscopic findings were observed and compared simultaneously. The results are summerized as follows: Patients age was distributed between 3 and 70 years old with highest incidence in the age group of sixty decade [33. 3%], and sex ratio of male to female was 5:2. The tuberculous processes which developed superficial subpleural layer in the lung parenchyme, on the pulmonary surface could be observed by thoracoscopic examination in a characteristic picture. detection ratio of pulmonary tuberculosis by the radiologic study to that by thoracoscopy was 8:2. The adhesion between the visceral and the parietal pleura which could possibly make a rupture of the alveola and the visceral pleura was found to be localized in a small area of the lung surface. The other part of the lung surface was free of the adhesion and, therefore, the movement of the lung took place completely without any difficulty. The ruptured orifice of the pleura and pathological changes surrounding the orifice can be detected by thoracoscopy, but not by other means such as radiologic examination. A single tuberculous bleb and multiple emphysematous blebs were found on 6 cases out of 21 cases of spontaneous pneumothorax. Among these cases, radiologic Study revealed the bleb only in one patient. On the other hand, the blebs were found in all the six patients by means of thoracoscopic examination. It gives the detection ratio of bleb by radiologic study to that by thoracoscopy was 1:6. By thoracoscopy, the rupture on the lung surface were visualized on the 10 patients out of a total of 21 patients [10 patients of visual rupture]. However, the rupture of the pleura was not observed on the rest of 11 patients even by thoracoscopic examination [11 patients of non visual rupture]. Five patients [50%] out of ten who had the visual rupture on the lung surface was required a surgical operation to remove pneumothorax. For the patients who were detected to have the visual rupture of the pleura by thoracoscopy, be considered in the early stage of closed thoracostomy. of 21 patients, 16 patients [11 patients of non visual rupture of the pleura and 5 patients of visual rupture of the pleura] who received no surgical management, were treated with closed thoracostomy with continuous suction, and the` pneumothorax was healed completely up in each cases. Therapeutic measures for the remaining 5 patients of visual rupture of the pleura who were subjected to surgical approach for radical treatment of spontaneous pneumothorax were accordingly complicated, and the following different procedures were properly indicated case by case, that is, rib resection thoracostomy, simple closure of ruptured visceral pleura, wedged resection of the lung, and lobectomy.

• Journal of Biosystems Engineering
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• v.23 no.5
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• pp.473-480
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• 1998

This study was performed to analyze the variation of various physicochemical factors related to the freshness of apple and tomato during post-harvest period. The total soluble solids content, uronic acid content, cell surface roughness. density, rupture deformation and rupture force were measured for 39 days at 7-day intervals for apple and for 11 days at 2-day intervals for tomato. respectively. The cell surface roughness of apple increased with the elapsed time, while the rupture force decreased. In case of tomato, uronic acid content, density and rupture deformation increased with the elapsed time whereas the rupture force decreased. Both apple and tomato exhibited the significant correlations among those physicochemical factors.

• Transactions of Materials Processing
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• v.18 no.4
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• pp.347-353
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• 2009

The apparent activation energy, the applied stress exponent, and rupture life have been measured from creep experiments over the range of $200^{\circ}C$ to $220^{\circ}C$ and the applied stress range of 64MPa to 94MPa. The materials were used AZ31 magnesium alloys treated by plasma electrolytic oxidation of $20{\mu}m$ and $40{\mu}m$ at surface to investigate the its influence on creep behavior, and creep tests were carried out under constant applied stress and temperature. The experimental results showed that the dipper the thickness of surface treatment the higher the activation energy and stress exponent. And the higher temperature and applied stress, the lower stress exponent and activation energy, respectively. Also the dipper the thickness of surface treatment the longer creep rupture time.

• Proceedings of the Materials Research Society of Korea Conference
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• 1994.11a
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• pp.180-180
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• 1994

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.897-900
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• 2012

We examined theory for force-induced unbinding on a two-dimensional free energy surface where the internal dynamics of biomolecules is coupled with the rupture process under constant tension f. We show that only if the transition state ensemble is narrow and activation barrier is high, the f-dependent rupture rate in the 2D potential surface can faithfully be described using an effective 1D energy profile.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.11 s.254
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• pp.1392-1400
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• 2006

Since the monolithic ceramic substrate was in introduced for automotive catalytic converters, the durability of the substrate has been a continuing requirement to reduce the emission, gas of vehicle. The substrate can occupy a volume as small as 82 $cm^3$ and as large as 8200 $cm^3$ to provide the required substrate for catalytic activity. The long-term durability varies with the size of the substrate from manufacture's point of view. Therefore this study presents that the response surface model using central composite design can explain size effect on the modulus of rupture in a cordierite ceramic monolithic substrate.

• Korean Journal of Materials Research
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• v.3 no.6
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• pp.575-584
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• 1993

The effects of atmosphere on the creep rupture properties of Ni-base superalloy Ren6 80 were investigated. Creep rupture tests were performed at $760^{\circ}C$, 657MPa and 982%, 157MPa under Ar gas atmospheres. Creep rupture mode and rupture properties (rupture life and elongation) were similar in two different atmospheres under the condition of $760^{\circ}C$, 657MPa. However, the results at $982^{\circ}C$, 157MPa showed different creep rupture mode and life between air and Ar gas atmospheres. In air, it was shown that creep cracks were initiated at surface-exposed grain boundaries and propagated along grain boundaries. In Ar gas atmosphere, the cracks were initiated at inner grain boundaries and coalesced to surface cracks which cause cup-and-cone type fracture. Due to protective oxide layer formation, air test showed longer rupture life than Ar test.

• Journal of the Korean institute of surface engineering
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• v.9 no.3
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• pp.5-8
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• 1976

In this study, a ruture strength of epoxy resin film coated on the leaking spot in waterpipe line was determined, using water pressure, without interrupting water supply. This results could be used for the sealing of water leakage in large size waterpipe lines. An experimental equation {{{{P=Kt^m~ /R^n~ (m=2, n=3.5) }} was also obtained, where P is the rupture pressure, K is constant, t is the thickness and R is the radius of the resin film. From this results, the safe쇼 thickness of the film for a domestic use was calculated with various radii against the maximum pressure.

• Geomechanics and Engineering
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• v.9 no.4
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• pp.427-445
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• 2015

By means of finite element numerical simulation and pseudo-static method, the shallow-buried bilateral bias twin-tube tunnel subject to horizontal and vertical seismic forces are researched. The research includes rupture angles, the failure mode of the tunnel and the distribution of surrounding rock relaxation pressure. And the analytical solution for surrounding rock relaxation pressure is derived. For such tunnels, their surrounding rock has sliding rupture planes that generally follow a "W" shape. The failure area is determined by the rupture angles. Research shows that for shallow-buried bilateral bias twin-tube tunnel under the action of seismic force, the load effect on the tunnel structure shall be studied based on the relaxation pressure induced by surrounding rock failure. The rupture angles between the left tube and the right tube are independent of the surface slope. For tunnels with surrounding rock of Grade IV, V and VI, which is of poor quality, the recommended reinforcement range for the rupture angles is provided when the seismic fortification intensity is VI, VII, VIII and IX respectively. This study is expected to provide theoretical support regarding the ground reinforcement range for the shallow-buried bilateral bias twin-tube tunnel under seismic force.