• 한국전자현미경학회:학술대회논문집
• /
• 2001.11a
• /
• pp.18-22
• /
• 2001

A technique to characterize specific site of materials using a combination of a dedicated focused ion beam system(FIB), and Intermediate-voltage scanning transmission electron microscope(STEM) or transmission electron microscope(TEM) equipped with a scanning electron microscope(SEM) unit has been developed. The FIB system is used for preparation of electron transparent thin samples, while STEM or TEM is used for localization of a specific site to be milled in the FIB system. An FIB-STEM(TEM) compatible sample holder has been developed to facilitate thin sample preparation with high positional accuracy Positional accuracy of $0.1{\mu}m$ or better can be achieved by the technique. In addition, an FIB micro-sampling technique has been developed to extract a small sample directly from a bulk sample in a FIB system These newly developed techniques were applied for the analysis of specific failure in Si devices and also for characterization of a specific precipitate In a metal sample.

• Geomechanics and Engineering
• /
• v.13 no.4
• /
• pp.571-584
• /
• 2017

Slope mass rating (SMR) is commonly used for the geomechanical classification of rock masses in an attempt to evaluate the stability of slopes. SMR is calculated from the $RMR_{89-basic}$ (basic rock mass rating) and from the characteristic features of discontinuities, and may be applied to slope stability analysis as well as to slope support recommendations. This study attempts to utilize the SMR classification system for slope stability analysis and to investigate the engineering geological conditions of the slopes and the slope stability analysis of the Gas Flare site in phases 6, 7 and 8 of the South Pars Gas Complex in Assalouyeh, south of Iran. After studying a total of twelve slopes, the results of the SMR classification system indicated that three slope failure modes, namely, wedge, plane and mass failure were possible along the slopes. In addition, the stability analyses conducted by a number of computer programs indicated that three of the slopes were stable, three of the slopes were unstable and the remaining six slopes were categorized as 'needs attention'classes.

• Journal of Chest Surgery
• /
• v.22 no.4
• /
• pp.648-654
• /
• 1989

A clinical study was performed on 363 cases of pulmonary tuberculosis treated surgically resection during the period of 3 years from January, 1986 to December, 1988 in the National Kong-Ju Hospital. The results obtained are follows: 1. The ratio of male to female was 1.6:1 in male predominance, age from 20 to 40 occurred 82.6% of the total cases. 2. The moderately advanced cases was the highest incidence with 53.2 % for extent of disease, duration of illness which 1 to 5 years before operation was 40.8 % of the total cases. 3. Preoperative sputum examination for AFB was 53.2 % in negative but in spite of chemotherapy, persistent positive sputum was 46.7%. 4. Indication for surgery were: total destroyed lung was 35.5 %, destroyed lobe or segment with or without cavity was 30.6%, empyema with or without bronchopleural fistula was 8.5%, according to type and site of surgical procedure, pleuropneumonectomy and pneumonectomy was the highest incidence with 53.4 %, left site was slightly more than right with 55.9 % of the total cases. 5. The incidence of postoperative complication was 10.2 % and then the highest incidence was empyema with or without bronchopleural fistula with 4%, according to type of surgical procedure, postpleuropneumonectomy and postpneumonectomy was 6.1 % of the total cases. 6. Postoperative mortality was 1.4 % of the total cases, according to cause of deaths, hypovolemic shock due to bleeding were 2 cases, respiratory failure were 2 cases and hepatic coma due to hepatic failure was 1 case.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.171-178
• /
• 2005

It is unavoidable to be formed slopes under special circumstance of Korea where 70% of the whole area are composed of mountains when civil engineering projects such as roads, site developments are increased with industrial development and horizontal expansions of urban area. Moreover, stability of the slopes become one of quite important issues under special meteorological characteristics that over two-thirds of annual average rainfall are concentrated in summer season and the localized torrential downpour are getting more frequent recently. Resulting in these circumstances, partial slope failures by debris flow of the high water content soils are occurred frequently in cutting soil slopes. In this case of debris flow slope failure, slope declination method are selected for their stable recovery because it is impossible to recover entirely by existing recovery methods. Seeding or special grass planting methods are followed separately without exception. The method by which entire recover with bigger stability ratio would be possible and grass planting work would be done simultaneously is developed. In this study, the results of the tests including a real construction history in a failed slope using developed method are described

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.35 no.4
• /
• pp.147-155
• /
• 2019

In this study, flexural tests of granite reinforced with titanium metal rods were carried out to repair and restore the damaged stone-made cultural heritage, the Stone Pagoda of the Mireuksa Temple Site. A total of twelve specimens were tested. The primary test parameters are the reinforcement ratio and the location of the reinforcement. For restoration, epoxy resin was used for joining the separated stones, and titanium metal rods were used for structural reinforcement. Test results showed that the flexural failure took place in specimens with a reinforcement ratio of 0.8% or less, and shear failure occurred when the reinforcement ratio was 1.68% or more. The peak load of the reinforced stone was found to be highly related to the reinforcement ratio. The peak load increased with increasing the reinforcement ratio. Also, the flexural behaviors of the reinforced stones were affected by the location of the reinforcement. Based on the test results, this study recommends the reinforcement ratio of the reinforced granite to induce ductile behavior.

• Geomechanics and Engineering
• /
• v.27 no.5
• /
• pp.481-495
• /
• 2021

This article assesses and estimates the progressive failure mechanism of complex pit-rest secondary toppling of slopes that are located within the vicinity of the Gas Flare Site of Refinery No. 4 in South Pars Special Zone (SPSZ), southwest Iran. The finite element numerical procedure based on the Shear Strength Reduction (SSR) technique has been employed for the stability analysis. In this regard, several step modelling stages that were conducted to evaluate the slope stability status revealed that the main instability was situated on the left-hand side (western) slope in the Flare Site. The toppling was related to the rock column-overburden system in relation to the overburden pressure on the rock columns which led to the progressive instability of the slope. This load transfer from the overburden has most probably led to the separation of the rock column and to its rotation downstream of the slope in the form of a complex pit-rest secondary toppling. According to the numerical modelling, it was determined that the Strength Reduction Factor (SRF) decreased substantially from 5.68 to less than 0.320 upon progressive failure. The estimated shear and normal stresses in the block columns ranged from 1.74 MPa to 8.46 MPa, and from 1.47 MPa to 16.8 MPa, respectively. In addition, the normal and shear displacements in the block columns ranged from 0.00609 m to 0.173 m and from 0.0109 m to 0.793 m, respectively.

• The Journal of Engineering Geology
• /
• v.22 no.1
• /
• pp.83-94
• /
• 2012

Slopes are commonly formed both above and below roads located in mountainous terrain and along riversides. The Buk-sil site, a cut slope formed below the road, collapsed in October, 2010. A field investigation determined the causes of failure as improper drainage of valley water from the slope above the road and direct seepage of road-surface water. These factors may have accelerated the collapse via complex interaction between water and sub-surface structures such as bedding. Projection analysis of the site showed the possible involvement of plane, wedge, and toppling failure. Safety factors calculated by Limit Equilibrium Analysis for plane and wedge failure were below the standard for wet conditions. The wetness index, analyzed using topographic factors of the study area, was 9.0-10.5, which is high compared with the values calculated for nearby areas. This finding indicates a high concentration of water flow. We consider that water-flow control on the upper road is crucial for enhancing slope stability at the Buk-sil site.

• The Journal of Engineering Geology
• /
• v.4 no.3
• /
• pp.343-356
• /
• 1994

When most of the industry and social indirect facilities such as the large structure, power plant or road, rail-road are constructed, the new slope may lead to the slope failure. The failure models for slopes have been developed by using the results of in-situ and laboratory tests to investigate the mechanisms and types of the slope failure. The safety factor of a slope may be obtained based on the proposed model and the slope can be reinforced to meet the design criteria. The slope should be reinforced by using the optimum model that properly reflects the site condition, the method of reinforcement includes the increased safety factor either by decreasing a slope angle or by reinforcing the slope.

• Wind and Structures
• /
• v.26 no.1
• /
• pp.45-56
• /
• 2018

Wind damage of urban trees arises to be a serious issue especially in the typhoon-prone areas. As a family of tree species widely-planted in Southeast China, the structural behaviors of Plane tree is investigated. In order to accommodate the complexities of tree morphology, a fractal theory based finite element modeling method is proposed. On-site measurement of Plane trees is performed for physical definition of structural parameters. It is revealed that modal frequencies of Plane trees distribute in a manner of grouped dense-frequencies; bending is the main mode of structural failure. In conjunction with the probability density evolution method, the fragility assessment of urban trees subjected to wind excitations is then proceeded. Numerical results indicate that small-size segments such as secondary branches feature a relatively higher failure risk in a low wind level, and a relatively lower failure risk in a high wind level owing to windward shrinks. Besides, the trunk of Plane tree is the segment most likely to be damaged than other segments in case of high winds. The failure position tends to occur at the connection between trunk and primary branches, where the logical protections and reinforcement measures can be implemented for mitigating the wind damage.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.742-753
• /
• 2008

Currently an increasing number of urban tunnels with small overburden are excavated according to the principle of the New Austrian Tunneling Method (NATM). Therefore, a possibility of a tunnel collapse during excavation is getting higher in a proportionate manner. This paper will analyze causes the failure mechanism of a shallow NATM tunnel for different geological conditions, ground-water and invert solutions by investigation typical collapse site during tunnel construction. In this paper, this analysis performed two phase, firstly, the field investigation considering displacement measurement, ground-water level, geological characteristic, secondly, the numerical simulation considering the exist of invert construction and the effect of ground-water. It has been found that environmental factors such as state of underground water or construction sequences could influence failure mechanism of a shallow tunnel.