• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.2
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• pp.90-101
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• 2009

Analysis of multi-channel seismic reflection data from the Southern Ulleung Basin reveals that Plio-Quaternary section in the area consists of nine stacked sedimentary units separated by erosional unconformities. On the southern slope, these sedimentary units are acoustically characterized by chaotic seismic facies without distinct internal reflections, interpreted as debris-flow bodies. Toward the basin floor, the sedimentary units are defined by well-stratified facies with good continuity and strong amplitude, interpreted as turbidite/hemipelagic sediments. The seismic facies distribution suggests that deposition of Plio-Quaternary section in the area was controlled mainly by tectonic movement and sea-level fluctuations. During the Pliocene, sedimentation was mainly controlled by tectonic movements related to the back-arc closure of the East Sea. The back-arc closure that began in the Miocene caused compressional deformation along the southern margin of the Ulleung Basin, resulting in regional uplift which continued until the Pliocene. Large amounts of sediments, eroded from the uplifted crustal blocks, were supplied to the basin, depositing Unit 1 which consists of debris-flow deposits. During the Quaternary, sea-level fluctuations resulted in stacked sedimentary units (2-9) consisting of debris-flow deposits, formed during sea-level fall and lowstands, and thin hemipelagic/turbidite sediments, deposited during sea-level rise and highstands.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.341-342
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• 2003

대기 중의 부유분진 (suspended particulate matters)은 대기오염을 측정하는 일반지표 중의 한 항목으로, 보통 대기의 단위부피당 질량으로 그 오염정도를 판단하고 있다. 대기 중 부유분진은 입경별 농도분포에 따라 통해 오염원의 특성을 파악할 수 있고, 여러 오염원에서 배출되어지는 여러 화학물질들로 구성되어 있기 때문에 인체 위해성 측면에서 많은 관심의 대상이 되어 왔다. 또한 다환방향족탄화수소 (Polycyclic Aromatic Hydrocarbons, PAHs)는 환경에 존재하는 중요한 발암물질이자 돌연변이 유도체이다.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.125-125
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• 2004

최근에 급속히 발달하고 있는 나노 기술(NT)파 생명공학 기술(BT)로 인해 미세한 영역에서의 역학적 측정이 중요시되고 있다. 질량, 힘, 온도, 압력 등의 기본적인 물리량들의 정확한 측정이 거시세계와 마찬가지로 나노 물질의 제조, 현상의 규명에 필수적인 요건이기 때문이다. 이중에서 미세 힘측정은 나노 압입 시험, 탄소나노튜브의 기계적 특성측정, MEMS 구조물의 특성평가, 근육 세포의 근력측정, DNA나 생체 분자력 측정 등 광범위하게 사용되고 있다.(중략)

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.159-161
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• 2001

지난 수 십년 동안 단위 길이당의 질량이나 지름의 변동은 섬유 공정 및 품질 관리에 있어서 매우 중요한 특성으로 알려져왔다. [1,2] 특히 방적사의 균제도는 최종 제품의 성능이나 외관을 결정하는 중요한 요인중의 하나로 그 특성을 밝히기 위해 불균제 지수, 스펙트로그램, 자기 상관 계수도 등이 사용되어져 왔다. (중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1993.07a
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• pp.82-85
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• 1993

해양구조물에 가장 이상적인 구조물의 형태중의 하나는 원형실린더인데, 그것은 같은 재질일 경우 단위무게당 가장 큰 힘을 지지할 수 있는 단면을 가지고 있고 또한 어느 방향으로의 외력에 대해서도 비교적 간단하게 해석할 수 있는 형상을 가지고 있다. 송유관 등의 목적으로 원형실린더를 해저에 설치함으로써 파이프라인이 형성되고, 공학적으로 볼 때 이에 대한 해석은 바닥경계를 고려하여 수평실린더에 작용하는 힘을 구하는 것으로 귀착된다고 할 수 있다. (중략)

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.92.2-92.2
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• 2011

차세대 에너지로 연료전지가 각광을 받고 있는 현재, 세계 각국에서는 연료전지의 상용화를 위해 노력하고 있다. 그러나 촉매분야에서 백금계 촉매의 사용량의 문제에 따른 매장량 한계점과 귀금속이라는 문제점이 존재하기 때문에 이에 대하여 대책강구가 필요한 시점이다. 이에 백금 촉매의 활성을 증대하고자 나노 크기의 제어 연구가 진행되고 있다. 또한, 촉매의 구조적인 면에 따라 촉매의 활성이 달라지는 점을 착안하여 백금계의 나노 형상 조절 연구와 백금계 촉매를 대체할 비백금계의 촉매 개발 연구가 활발히 진행되어지고 있다. 이에 본 연구는 백금계 촉매 중 Pd을 polyol process에 의한 나노 형상 조절을 통하여 단위 질량당(or 단위 부피당)촉매의 활성을 높이고자 하였다. 여기서 새로이 도입된 환원제는 Glycerol을 이용하였으며, {111}면이 많이 드러난 Pd 나노입자를 형성하였다. 이에 따라 나노 형상 조절이 된 Pd촉매를 이용하여 상용화된 촉매(Pd/C(XC-72R))에 비하여 전기화학적인 특성의 차이와 Pd 촉매의 촉매적 특성의 효과를 보고자 한다.

• KSBB Journal
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• v.17 no.1
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• pp.26-32
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• 2002

The aerobic bacterium Xanthomonas campestris was cultivated continuously in a three-phase fluidized bed bioreactor to produce extracellular polysaccharide xanthan, Fluidized particles of 8.0 mm glass beads were used for disintegrating the large air bubbles even at high viscosities to improve the gas-liquid oxygen transfer rate. Xanthin productivity [kg xanthan/kg cell dry mass·h] and molecular weight increased, with dilution rate in the continuous xanthan fermentations. The specific xanthan productivities were not limited by the oxygen transfer rate and were much higher in the continuous cultivations than those predicted by the results of the batch xanthan fermentations.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.93-100
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• 2002

For natural gas and LPG fuel, measurements on the concentrations of individual exhaust hydrocarbon species have been made as a function of air-fuel ratio in a 2-liter four-cylinder engine using a gas chromatography. NMHC in addition to the species of HC, other emissions such as CO$_2$, CO and NOx were examined for natural gas and LPG at 1800rpm far two compression ratios (8.6 and 10.6). Fuel conversion efficiencies were also investigated together with emissions to study the effect of engine parameters on the combustion performances in gas engines especially under the lean bum conditions. It was found that CO$_2$ emission decreased with smaller C value of fuel, leaner mixture strength and the higher compression ratio. HC emissions from LPG engine consisted primarily of propane (larger 60%), ethylene and propylene, while main emissions from natural gas were mothane (larger than 60%), ethane, ethylene and propane on the average. The natural gas was proved to give the less ozone formation than LPG fuel. This was accomplished by reducing the emissions of propylene, which has relatively high MIR factor, and propane that originally has large portion of LPG. In addition, natural gas shows a benefit in other emissions (i.e. NMHC,NOx, CO$_2$and CO), SR and BSR values except fuel conversion efficiency.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.4
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• pp.97-103
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• 2017

As the shortage of concrete aggregates is intensifying, the development of alternative resources is urgent. As the amount of steel slag increases year by year, attempts are being made to recycle slag into high-value-added products in order to develop an efficient resource recycling industry based on slag and to obtain economic benefits. However, the use of electric arc furnace oxidizing slag (EOS) as building materials is practically limited because it contains unstable materials. In this paper, physical properties of concrete were evaluated by using electric arc furnace slag aggregate. It has been produced with two levels of general strength area W / C 45% and high strength area W / C 30%. Fresh concrete has been tested in air content, flow and slump, unit weight. The properties of the cured concrete were investigated by compressive strength, bending strength and unit volume weight. As a result of this study, strength of concrete increased with increasing EOS aggregate mixture.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.101-108
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• 2015

The quantities of heavy weight waste glass have been progressively increased because of the rapid industrialization and the change of quality of life. And, the most of them are not recycled. The heavy weight waste glass have been treated by illegal dumping or being buried in landfills. Meanwhile, in order to ensure the safety of nuclear power plant structure, the excellent construction materials are socially required for shielding performance. Concrete is the most widely used construction material, the huge amounts of natural resources are required to make concrete. So, it is needed to investigate the possibility of recycling of heavy weight waste glass as concrete material ingredient. In this study, the heavy weight waste glass was evaluated for the applicability as fine aggregate of shielding concrete. From the results, when heavy weight waste glass was replaced as fine aggregate of mortar, shielding performance can be improved due to increasing in unit weight of mortar. It showed that the strength decreased according to mixing of heavy weight waste glass, Non-Washed heavy weight waste glass is more advantageous in the strength development than Washed case.