• Journal of the Korean Society of Safety
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• v.23 no.1
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• pp.1-11
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• 2008

In this study, small punch test and tensile test were performed with specimens directly machined from an ASTM A53 grade B carbon steel pipe at which an explosion accident was occurred in the Heavy Oil Unit. Main damage mechanism of the pipe was known as a high temperature hydrogen attack(HTHA). Effects of HTHA on the mechanical strength change of the A53B steel were studied in detail. Small punch test results have showed that maximum reaction forces, SP energy and ductility were decreased at hydrogen attacked part of the pipe compared with sound part of the pipe. Yield strength and tensile ultimate strength were calculated with the obtained small punch test curve results using different methods and compared the estimation methods. Small punch test simulation has been also performed with the finite element method and then mechanical strength, equivalent strain and fracture toughness were calculated with the obtained numerical analysis results. It was shown that the fracture toughness data calculated from small punch equivalent energy obtained by the finite element analysis for SP test was very low at the hydrogen attacked part.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.340-345
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• 2016

Railway vehicle battery is supplying the power required for the initial start-up of the train, in the event of a fault in the vehicle, or catenary for supplying emergency power is one of the components are very important. Currently, the railway vehicles such as nickel-cadmium batteries are being used [1,2]. Ni-Cd batteries as a battery installed in the railway vehicles have a strong corrosion resistance is included, The charge-discharge performance is significantly degraded in cold weather, there is a danger of deterioration or explosion. Train accidents have been caused a lot of damage due to rapid deterioration and cracking of the battery and memory due to the effect of Ni-Cd batteries. In order to solve the problems, There is no risk of degradation, deterioration and leakage, cracking and exploding. maintenance is simple and applied measures proposed to apply Lithium Polymer battery of high performance. In addition, the lack of capacity problems identified by testing the different special systems is replaced by a 70Ah lithium-polymer battery is possible without changing the batteries of 50Ah caused by installing additional equipment in existing older trains were applied to the vehicle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1201-1209
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• 2008

In Seoul, there are lots of skyscrapers that have above 60 stories and buildings that have more than 8 basement levels, as well as massive distribution complex region which is connected to subways, departments, malls, hotels, and exhibition halls. When an accident, such as fire and explosion, happens in these areas or structures, if we can't find where fire-fighters are, who go into the building to suppress the fire, we couldn't be sure of their safety as well as effective command. Actually, it may cause much more damage itself and restrict either fire suppression or lifesaving. To protect people's life and properties as much as possible, this study will show the method to construct system of disaster-management supports with effective operation of fire force and scientific fire strategy in the scene by using Ubiquitous technique to enormous disasters.

• Earthquakes and Structures
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• v.12 no.5
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• pp.529-541
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• 2017

According to the definition, progressive collapse could occur due to the initial partial failure of the structural members which by spreading to the adjacent members, could result in partial or overall collapse of the structure. Up to now, most researchers have investigated the progressive collapse due to explosion, fire or impact loads. But new research has shown that the seismic load could also be a factor for initiation of the progressive collapse. In this research, the progressive collapse capacity for the 5 and 15-story steel special moment resisting frames using push-down nonlinear static analysis, and nonlinear dynamic analysis under the gravity loads specified in the GSA Guidelines, were studied. After identifying the critical members, in order to investigate the seismic progressive collapse, the 5-story steel special moment resisting frame was analyzed by the nonlinear time history analysis under the effect of earthquakes with different characteristics. In order to account for the initial damage, one of the critical columns was weakened at the initiation of the earthquake or its Peak Ground Acceleration (PGA). The results of progressive collapse analyses showed that the potential of progressive collapse is considerably dependent upon location of the removed column and the number of stories, also the results of seismic progressive collapse showed that the dynamic response of column removal under the seismic load is completely dependent on earthquake characteristics like Arias intensity, PGA and earthquake frequency contents.

• Natural Product Sciences
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• v.15 no.2
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• pp.71-75
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• 2009

The great economic and social damage caused by unusual explosion of jellyfish population has attracted the attention of researchers. A chemical study on the bioactive components of the giant jellyfish Nemopilema nomurai led to the isolation of two new (1 and 2) and three known alkoxyglycerols (3 - 5), along with known monoglycerides (6 - 7) and fatty acids. Based on NMR and MS data, the structures of compounds 1 and 2 were elucidated as 1-O-[(Z)-tetradec-3-enyl]-sn-glycerol and 1-O-[(Z)-octadec-10-enyl]-sn-glycerol, respectively. The absolute configurations of compounds 1 - 7 were determined by comparison of specific optical rotation values with those reported. The isolated compounds were evaluated for suppressive effect on the proinflammatory mediators (NO, IL-6, and TNF-${\alpha}$) in murine macrophage cells. However, they were found inactive upto the concentration of 100 ${\mu}M$.

• Journal of Trauma and Injury
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• v.30 no.1
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• pp.12-15
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• 2017

A 58-year-old male visited our emergency room for multiple traumas from explosion. On initial evaluation, hemopneumoperitoneum with liver laceration (grade 4) and colon perforation was identified. Hemopericardium with cardiac tamponade was also identified. Shrapnel was detected in the right ventricle. Damage control surgery was planned due to condition of hypotension. In operation room, control over bleeding was achieved after sternotomy, pericardiotomy, and laparotomy. Massive transfusion was done during operation. After gauze packing, operation was terminated with temporary closure (TC). Sanguineous fluid was drained profusely. Disseminated intravascular coagulopathy was confirmed through laboratory findings. No extravasation was discovered at hepatic angiogram. On re-operation, there was no active bleeding but oozing from sternotomy site was identified. Bone bleeding was impossible to control. Finally, reoperation was ended after gauze packing and TC all over again. The patient could survive for only a day after re-operation.

• Journal of Ocean Engineering and Technology
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• v.34 no.2
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• pp.110-119
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• 2020

Explosions and fires on offshore drilling units and process plants, which cause loss of life and environmental damage, have been studied extensively. However, research on drilling units increased only after the 2010 Deepwater Horizon accident in the Gulf of Mexico. A major reason for explosions and fires on a drilling unit is blowout, which is caused by a failure to control the high temperatures and pressures upstream of the offshore underwater well. The area susceptible to explosion and fire due to blowout is the drill floor, which supports the main drilling system. Structural instability and collapse of the drill floor can threaten the structural integrity of the entire unit. This study simulates the behavior of fire subsequent to blowout and assesses the thermal load. A heat transfer structure analysis of the drill floor was carried out using the assessed thermal load, and the risk was noted. In order to maintain the structural integrity of the drill floor, passive fire protection of certain areas was recommended.

• Journal of the Korean Institute of Gas
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• v.17 no.2
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• pp.44-49
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• 2013

Due to rapid rise of consuming rate for natural gas, installation and operation of high pressure natural gas pipeline is inevitable for high rate of gas transportation. Accordingly incidents on the underground high pressure natural gas pipeline come from various reasons will lead to massive release of natural gas and gas dispersion in the air. Further, fire and explosion from ignition of released gas may cause large damage. This study is for release rate, dispersion and flash fire of natural gas to establish a safety management system, setting emergency plan and safety distance.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.159-165
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• 2014

For the hydrogen economy system being tried starting with the 21st century, the fields that was not dealt with so far, such as the safety measure for large leakage accidents, the safety problem at infrastructures like a hydrogen station, the safety problem in terms of automobiles depending on introduction of hydrogen cars, the safety problem in a supply for homes like fuel cells, etc., are being deeply reviewed. In order to establish a safety control system, an essential prerequisite in using and commercializing hydrogen gas as an efficient energy source, it is necessary to conduct an analysis, such as analysis of hydrogen accident examples, clarification of physical mechanisms, qualitative and quantitative evaluation of safety, development of accident interception technologies, etc. This study prepared scenarios of hydrogen gas leakage that can happen at hydrogen stations, and predicted damage when hydrogen leaks by using PHAST for this.

• Structural Engineering and Mechanics
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• v.45 no.6
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• pp.803-819
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• 2013

This paper addresses two main issues relevant to the structural assessment of buildings subjected to explosions. The first issue regards the robustness evaluation of steel frame structures: a procedure is provided for computing "robustness curves" and it is applied to a 20-storey steel frame building, describing the residual strength of the (blast) damaged structure under different local damage levels. The second issue regards the precise evaluation of blast pressures acting on structural elements using Computational Fluid Dynamic (CFD) techniques. This last aspect is treated with particular reference to gas explosions, focusing on some critical parameters (room congestion, failure of non-structural walls and ignition point location) which influence the development of the explosion. From the analyses, it can be deduced that, at least for the examined cases, the obtained robustness curves provide a suitable tool that can be used for risk management and assessment purposes. Moreover, the variation of relevant CFD analysis outcomes (e.g., pressure) due to the variation of the analysis parameters is found to be significant.