• Journal of the Speleological Society of Korea
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• v.25 no.26
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• pp.15-28
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• 1991

제주도는 세계에서 이름난 화산동굴의 보고라고 불리운다. 그 동굴의 길이 뿐만 아니라 그 규모 그리고 그들 동굴속에 간직하고 잇는 갖가지 동굴의 지형지물등 하나하나가 모두 세계 제1 또는 세계적인 것들에 많이 집중분포하고 있기 때문이다. 한편 환산동굴은 용암동굴 핏트동굴 리프트동굴등으로 다시 세분하기도 하는데 핏트동굴은 리프트 동굴과 같이 매우 희귀한 것으로 화산활동때에 분출된 화산탄이나 화산력 그밖에 화산계등으로 되는 화도가 그대로 남아서 수직구멍을 이루고 있는것을 가리킨다. 그리고 리프트동굴이란 마그마가 화도속에 가득차 있는 상태이면서도 수직동굴이 남아 있는 경우를 말한다.(중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.274-275
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• 2000

현재 우리 나라는 공단지역에서 발생하는 VOCs(휘발성 유기화합물) 및 악취의 처리에 대한 연구개발 및 기존기술이 매우 취약한 실정이며, 일부 화학공장에서는 축열식 연소장치나 촉매연소장치를 설치하여 운전하고 있지만, 유지비(보조연료비)가 많이 소요되어 제대로 가동하지 못하는 경우가 있다. 대부분 제조업체의 경우, 활성탄 흡착탑을 설치하여 운영하지만, 화학공장에서 발생하는 포름알데히드, 스티렌 등과 같은 일부 물질은 흡착탑 내부에 타-르 같은 물질이 침적하고, 활성탄에 의한 흡착율이 낮다. (중략)

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.152-152
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• 2019

• Economic and Environmental Geology
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• v.54 no.2
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• pp.187-197
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• 2021

The Hyeongjeseom (Islet) is an erosional remnant of volcano which is located about 2 km northeast of sea shore of the Songaksan tuff ring, and is composed of volcaniclastic deposit, agglomerate and scoria deposit, ponded lava, aa lava flows, reworked deposit and beach deposit in ascending order from the base. The volcano is formed by volcaniclastic deposits and lava flows that recorded a transition from initial phreatomagmatic to magmatic explosions followed by lava effusion. It is interpreted that the outcropped volcaniclastic deposit may be a remaining portion of outer ring of a tuff cone. A bomb and a ponded lava yield geochemically basaltic trachyandesite compositions (SiO2 51.3 wt%, Na2O+K2O 6.0 wt%) and belong to olivine basalt with scarce (<5 %) phenocrysts of olivine, petrographically. By incremental heating Ar-Ar dating method, the plateau age of lava flow in the Heongjesom is 9.2±3.6(2σ) ka, implying that the volcanism of Heongjeseom may have occurred earlier than the Songaksan tuff ring which erupted ca. 3.7 ka. It still remains a task to find a volcano which matches with a historical record of volcanic activity that occurred a thousand years ago.

• Journal of the Korean earth science society
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• v.28 no.4
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• pp.462-477
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• 2007

The purpose of this study is to determine the petrology of basalt and the volcanic process in the Seondol cinder cone, Seobjikoji area, eastern Jeju Island. The Seondol cinder cone is mainly composed of spatters in the lower part, pyroclastic deposits including reddish brown blocks, ashes with volcanic bombs in the middle part, and dark black scoria deposits in the upper part. The volcanic sequences suggest volcanic processes that progress through Strombolian eruption and end with Hawaiian lava effusion which breached the cinder cone northwestward and extended over northwestward as lava delta and basalt emplaced as a volcanic neck in the central part of crater in the cinder cone. The age of basalt lava flows is about $95\;{\pm}\;3\;ka$. The basalts belong to transitional basalt and show products of fractional crystallization of clinopyroxene and olivine from a parental basalt magma on the basis of variation diagram of major, trace and rare earth elements. Basalts in the region of this study are plotted at the region of within plate basalt.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.102-109
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• 2012

In this study, the four different filter media (sponge, volcanic stone, activated carbon and magnesium hydroxide) were tested for the removal of algae and phosphorus in the two eutrophic water samples (natural water and artificial algal culture with BG-11 medium). These filter media were used in the column device as single or combined applications. The effect of the $Mg(OH)_2$ on phosphorus removal was examined using different particle sizes (<2 mm and >2 mm) and concentrations (0, 10, 50 and 100 g $L^{-1}$) of magnesium hydroxide. The removal efficiency of phosphate by magnesium hydroxide was increased with longer experimental time and higher concentration. However, there was no significant difference in the degree of phosphorus removal between any two particle sizes (1 mg P $L^{-1}$: F=0.109, P=0.685; 10 mg P $L^{-1}$: F=1.542, P=0.355). Among the four media, activated carbon showed the most potent effect on the removal of both algae and phosphorus. The highest removal efficiency of algae and phosphorus was obtained by combining four columns of each filter medium. Interestingly, integration of four filter columns showed higher removal efficiency than activated carbon alone. The highest removal efficiency by integrated filter columns seemed to be caused by a synergistic effect of combined activated carbon and magnesium hydroxide.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2022.10a
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• pp.381-382
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• 2022

국내에서 1980년대까지 연탄을 에너지로 많이 사용하면서 일산화탄소 중독이 빈번하여 고압산소치료가 활용되다가 이후 연탄 사용의 감소로 고압산소치료기가 대부분 활용되지 못하고 폐기되는 경우도 많았다. 이후 세월호 사고에서의 잠수사들에 대한 고압산소치료 적용, 가스누출이나 번개탄을 활용한 자살시도가 빈번해지며 고압산소치료기를 보유하고 있는 기관이 부족해 적절한 치료를 제 때 받지 못하여 고압산소치료기의 필요성이 되두되었다. 국내에서는 2021년 기준으로 한해 36,266 건의 화재가 발생하고 2020년에 365명이 화재로 사망하며, 화재로 인한 손상은 1,917건이었는데. 화재 시 여러 유독가스를 흡입하게 되고, 이에 따라 고압산소치료가 필수적으로 진행되어야 한다. 유해화학물질 사고, 대규모 오염, 다양한 교통수단에서의 대형 사고, 건축물 붕괴 사고 및 대규모 지진, 화산폭발 같은 자연재해 시에도 가스 중독이 발생하며, 이는 고압산소치료가 필요하게 된다. 따라서 다양한 종류의 재난에서 발생하는 유독가스 피해자에게 고압산소치료는 필수적이나 본 연구에 의하면 국내에는 고압산소치료챔버의 숫자와 동시에 고압산소치료로 수용할 수 있는 환자수에도 한계가 있고 그 분포의 불균형도 존재하고 있어 재난 시 인명 피해 감소의 기반 장비, 시설로서 고압산소챔버의 균형있는 확산, 적용이 시급한 실정이다. 다행히 최근 전국적으로 고압산소챔버가 증가하는 추세에 있어 그 현황과 배치 상황을 조사하여 이를 통하여 고압산소챔버가 필요한 유독가스 발행 재난에 대비할 수 있는 역량이 증가하고 있다.

• The Journal of Engineering Geology
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• v.24 no.3
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• pp.373-381
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• 2014

It is difficult to predict the magnitude of a rockfall with respect to the shape, volume, and weight of the rock mass, as a rockfall exhibits erratic behavior that depends on the slope geometry, such as the height and dip of the slope. In this study, a field survey was conducted on the slopes of Ulleung-Do, South Korea, where rockfalls frequently occur along coastal roads, to classify the mode of rockfalls and estimate their magnitude. This study also analyzed the effects of rockfall behavior on roads by applying a simulation technique. Agglomerate and trachytic rocks distributed across the study area produce rockfalls in a differential weathering rockfall mode and a toppling rockfall mode. In terms of rockfall weight, trachytic rockfalls were 2-3 times heavier than agglomerate rockfalls. An analysis of rockfall behavior from the simulation indicates that the impact energy on the road exceeded the absorbing energy of a standard rockfall protection fence; however, the rockfall was secured when a ring-net was applied.

• Geophysics and Geophysical Exploration
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• v.25 no.1
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• pp.38-43
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• 2022

In case axial symmetrical bodies with varying cross sections such as volcanic conduits and unexploded ordnance (UXO), it is efficient to approximate them by adding the response of thin disks perpendicular to the axis of symmetry. To compute the vector magnetic and magnetic gradient tensor respones by such bodies, it is necessary to derive an analytical expression of the circular disk. Therefore, in this study, we drive closed-form expressions of the vector magnetic and magnetic gradient tensor due to a circular disk. First, the vector magnetic field is obtained from the existing gravity gradient tensor using Poisson's relation where the gravity gradient tensor due to the same disk with a constant density can be transformed into a magnetic field. Then, the magnetic gradient tensor is derived by differentiating the vector magnetic field with respect to the cylindrical coordinates converted from the Cartesian coordinate system. Finally, both the vector magnetic and magnetic gradient tensors are derived using Lipschitz-Hankel type integrals based on the axial symmetry of the circular disk.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.116-127
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• 2013

At weekly intervals, we monitored continuous changes in water quality by constructed floating wetland equipped with the four different filter media (sponge, volcanic stone, activated carbon and magnesium hydroxide) in a eutrophic lake from March 2011 to May 2012. We also investigated phyto- and zooplankton communities both in the influent and the effluent water through the floating wetland. Over a 10-month time period, average turbidity (66%), suspended solids (79%) and chlorophyll-a (80%) concentrations were remarkably reduced in the effluent water compared to the influent (P<0.001). The average removal rates of $NO_2-N$ and $NH_3-N$ were 24% and 20%, respectively (P<0.05). The average removal rates of $NO_3-N$ and TN were less than 10% (P>0.05). On the other hand, the average removal rates of $PO_4-P$ and TP were more than 65% (P<0.01). Interestingly, the abundance of phytoplankton in the effluent was decreased about 2.6 times compared to that of the influent, whereas the abundance of zooplankton in the effluent was increased about 3.5 times compared to that of the influent. Overall, particulate matters (SS, Chl-a and TP) and dissolved nutrients ($NO_2-N$, $NH_3-N$ and $PO_4-P$) were particularly reduced at high rates. Therefore, application of our constructed floating wetland in a eutrophic lake improved the water quality and demonstrated a potential for algal bloom mitigation.