• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.06a
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• pp.101-107
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• 2000

가연성 가스가 누출함에 따른 화재 및 폭발 재해는 공업화 사회에 있어서 방치될 수 없는 매우 중요한 문제이다. 기체, 액체, 분체가 단면적이 작은 분출구를 통해 공기중으로 분출될 때 분출하는 물질과 분출구와의 마찰로 인해 정전기가 발생한다. 분출되는 물질과 분출구를 구성하는 물질의 직접적인 마찰에 의해서도 정전기가 발생하고, 분출되는 물질 구성입자들간 상호충돌에 의해서도 정전기가 발생된다. 배관 내에 순수천연가스가 이송ㆍ분출할 때의 대전량은 매우 작다. (중략)

• The Journal of the Petrological Society of Korea
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• v.14 no.4 s.42
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• pp.251-263
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• 2005

Modern volcanoes, Laoheishan and Huoshaoshan, have erupted during $1720\~1721$ in the Wudalianchi volcanic group, NE china. They comprise scoria and spatter cones that consist of potassium-rich phono-tephritic pyroclastic deposits and lavas, and include wide lava flow fields. The Laoheishan scoria cone is a polygenetic multiple volcano that overlaps earlier and later edifices with more complicated internal structures produced in greater scale and in earlier time than the Huoshaoshan. There is a funnel-shaped crater in the center of the later edifice of the Laoheishan scoria cone. The Huoshaoshan spatter cone is a monogenetic simple volcano with a central pit crater. The volcanic sequences indicate eruption processes that followed a repeated pattern that progressed through 5 stages of explosive and effusive eruption including lava fountains and Strombolian eruptions in the Laoheishan, and a recognizable pattern of 2 stages that started with Strombolian eruption and progressed through lava effusion in the Huoshaoshan.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.11a
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• pp.333-339
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• 2000

현대사회의 공업화 및 도시화에 따라 NG(Natural Gas)를 포함하는 일반 가연성 가스의 누출에 의한 화재 및 폭발 재해는 매우 중요한 문제이다. 기체, 액체 및 분체가 단면적이 작은 분출구를 통해 공기중으로 이송 및 분출될 때 분출물질과 분출구와의 마찰로 인해 정전기가 발생한다./sup 1)/ 배관 내에 순수 NG가 이송·분출될 때의 대전량은 매우 작다./sup 2,3)/ 그러나, 배관 내에는 벤트스텍 등 외부에서 유입되는 먼지 또는 배관내의 부식에 의한 산화철(Fe₂O₃) 등의 분체가 포함될 수 있으며 이러한 분체가 천연가스 등과 함께 분출될 때 배관과의 마찰로 인해 대전량이 크게 상승된다./sup 3,4)/ 또한 분출되는 물질 구성입자들간 상호충돌에 의해서도 대전량은 더욱 증가하게 된다./sup 5)/(중략)

• Proceeding of EDISON Challenge
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• 2016.11a
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• pp.71-73
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• 2016

기존 우산의 단점을 보완한 발명품, 공기우산이 개발되었다. 하지만 공기우산의 단점인 짧은 사용시간을 보완하기 위해 강우량에 따라 적절하게 공기 분사압을 변화시키는 것뿐만 아니라 공기우산의 사용인원의 조절을 위해 압력비와 분사구 형태에 따른 우산의 효과를 알아보는 것이 실 사용에 중요한 요소일 것이다. 이에따라 본 연구에서는 우산 앞 부분의 분출구 형상과 자유류와의 분사 압력비에 따른 자유류의 방어 능력을 확인해 보았다. 평면 분사구에서 압력비가 1.3, 1.5인 구간에서는 우산의 효과를 나타낼 수 없었고 압력비가 1.5인 구간부터 삼각형 분사구와 육각형 분사구에서 우산의 형태가 나타남을 알 수 있었다. 압력비가 2.0인 구간에서 육각형 분사구의 경우 통상적인 우산의 형상을 보이기 시작하는 것을 알 수 있다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.230-230
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• 2011

대기압 플라즈마 제트 장치의 분출구 크기에 따른 플라즈마 분출 특성을 조사한다. 플라즈마가 분출되는 홀 모양의 방전관 출구의 직경 0.2, 0.5, 0.7, 1.0 mm에 대하여 비교 실험하였다. 플라즈마 제트 장치는 원통형 바늘 전극을 유리관 속에 삽입하고, 가스가 주입되는 형태이이다. 방전 가스는 Ar을 사용했으며 유량은 5 lpm이다. DC-AC 인버터를 사용하여 주파수 45 kHz 수 kV의 고전압을 인가하여 플라즈마 제트 장비를 구동한다. 직경이 작을수록 방출되는 플라즈마가 가늘고 방전 전압이 낮다. 직경이 작을수록 분출량 미세 조절이 용이하고 또한 낮은 방전 전압으로 인체 실험에 적용하는 경우에 전기적 충격이 적을 것으로 예상된다.

• Journal of the Korean Institute of Gas
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• v.16 no.4
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• pp.59-64
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• 2012

The dispersion of gas discharged from the vent pipes of pressure relief valves attached LPG (Liquefied Petroleum Gas) storage tank was studied. In general, vent pipes should be positioned so that they discharge vertically upwards in a safe place, and installed so that, in the event of ignition of discharged gas, flame impingement on any vessel, equipment or piping is avoided[1][2]. In Korea, on the other hand, there are various type of the end of vent pipes because there is no rule for discharge directions from the vent pipes. In this paper, we took 4 types of vent directions from the pipes in to account, such as vertically upward, vertically downward, vertically 4-way and horizontally 2-way direction. A software package, FLACS, was adopted to simulate gas dispersion from the vent pipes. We found that vertically downward, vertically 4-way and horizontally 2-way discharge from vent pipes were undesirable to avoid ignition on near ground. Therefore, it was obvious that vertically upward opening of a vent pipe is the best option to discharge in a safe place.

• The Journal of the Petrological Society of Korea
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• v.7 no.1
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• pp.1-14
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• 1998

Dangsanbong volcano, which is located on the coast of the western promontory of Cheju Island, occurs in such a regular pattern on the sequences which represent an excellent example of an eruptive cycle. The volcano comprises a horseshoe-shaped tuff cone and a younger nested cinder cone on the crater floor, which are overlain by a lava cap at the top of the cinder cone, and wide lava plateau in the moat between two cones and in the northern part. The volcanic sequences suggest volcanic processes that start with Surtseyan eruption, progress through Strombolian eruption and end with Hawaiian eruption, and then are followed by rock fall from sea cliff of the tuff cone and by air fall from another crater. It is thought that the eruptive environments of the tuff cone could be mainly emergent because the present cone is located on the coast, and standing body of sea water could play a great role. It is thought that the now emergent part of the tuff cone was costructed subaerially because there is no evidence of marine reworking. The emergent tuff cone is characterized by distinctive steam-explosivity that results primarily from a bulk interaction between rapidly ascending magma and external water. The sea water gets into the vent by flooding accross or through the top or breach of northern tephra cone. Dangsanbong tuff cone was constructed from Surtseyan eruption which went into with tephra finger jetting explosion in the early stage, late interspersed with continuous upruch activities, and from ultra-Surtseyan jetting explosions producting base surges in the last. When the enclosure of the vent by a long-lived tephra barrier would prevent the flooding and thus allow the vent to dry out, the phreatomagmatic activities ceased to transmit into magmatic activity of Strombolian eruption, which constructed a cinder cone on the crater floor of the tuff cone Strombolian eruption ceased when magma in the conduit gradually became depleted in gas. In the Dangsanbong volcano, the last magmatic activity was Hawaiian eruption which went into with foundation and effusion of basalt lava.

• Economic and Environmental Geology
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• v.41 no.1
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• pp.81-92
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• 2008

Fonualei Rift and Spreading Center(FRSC) and Mangatolu Triple function(MTJ) caldera are located in northeastern part of Lau basin which is the active back-arc basin. Deep-tow and surface-tow magnetic surveys are carried out in FRSC. In deep-tow magnetic survey, to compensate for influence of uneven distance between bathymetry and sensor height, magnetic anomaly is continued upward to a level plane by using the Guspi method. We calculate crustal magnetization using Parker and Huestis's inversion algorithm, and try to find the hydrothermal vent and understand the structure of ocean floor crust. The result of deep-tow magnetic survey at FRSC showed that Central Anomaly Magnetization High(CAMH) recorded the max value of 4.5 A/m which is associated with active ridge. The direction of SSW-NNE corresponds with the direction of the principal spreading ridge in Lau basin. The low crustal magnetizaton$(174^{\circ}35.1'W,\;16^{\circ}38.4'S)$ of -4.0 A/m is supposed to correlate with submarine hydrothermal vent. Surface-tow magnetic data were collected in MTJ caldera$(174^{\circ}00'W,\;15^{\circ}20'S)$. The prevailing SSW-NNE direction of collapsing walls and the presence of CAMH at the center of caldera strongly indicate the existence of active spreading ridge in ancient times.

• Journal of Convergence for Information Technology
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• v.11 no.7
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• pp.111-117
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• 2021

This research work is to suggest the experimental results capable of solving an initial unsuitability of combustion and environment in a constant volume combustion chamber by using LFG(Land Fill Gas) which consists of 40% CO₂ and 60% CH₄. The experimental condition is set as 0.9~1.6 of air-fuel ratio, 3bar of combustion pressure, 25℃ of room temperature, methane for using gas, and 2.5~4.5 of Pre-chamber hole sizes. As a result, it can be seen that diffusion of initial flame is significantly increased by M3.0 model comparing with other one. The reason for the characteristics is that orifice effect is extremely improved by 0.9, 1.0, and 1.2 of air-fuel ratio comparing with other one. Consequently, this experiment is shown that M3.0 model is partially capable of improving combustion performance than a conventional ignition plug in case of applying to LFG with Pre-chamber design.

• The Journal of the Petrological Society of Korea
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• v.22 no.3
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• pp.235-249
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• 2013

The Gusandong Tuff (Kusandong Tuff), known as a very significant key bed in the Cretaceous Gyeongsang Basin, is divided into (1) Northern Gusandong Tuff (NKT), (2) Southern Gusandong Tuff (SKT), and (3) Sinsudo Tuff, which were derived from different vents. In order to suggest their more accurate eruption times and to contribute to establishing stratigraphy of the basin, SHRIMP U-Pb zircon ages were determined from the three tuffs. As a result, the virtually same ages of $103.0{\pm}1.2$ Ma and $104.1{\pm}1.3$ Ma were obtained from NKT and SKT, respectively, which mean that they simultaneously erupted during 103~104 Ma. The zircon ages obtained from the Sinsudo Tuff are however divided into two groups i.e. $103.4{\pm}2.1$ and $95.79{\pm}0.98$ Ma. Based on distinctive morphology and cathodoluminescence image of the younger zircons, the younger age, $95.79{\pm}0.98$ Ma, is much more reasonable as the eruption time of the Sinsudo Tuff.