• Economic and Environmental Geology
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• v.35 no.5
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• pp.429-436
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• 2002

Core samples, drilled in the middle region of Bavaria, were analyzed to study the characteristics of organic matter in the Upper Jurassic Solnhofen limestone of southern Germany. The core (48$^{\circ}$53'N, 1-1$^{\circ}$19'E) contains Upper Jurassic Solnhofen strata ranging from the upper part of the Geisental Formation throughout the Solnhofen Formation to the lower part of the Mornsheim Formation. In the core, the Upper Jurassic lithologies consist of platy limestone, bedded limestone and massive limestone often interbedded with some chert layers. Geochemical variations (Carbon, Nitrogen and Total Organic Carbon) and Rock-Eval pyrolysis parameters (S$_2$ peak and Hydrogen Index) indicate that the organic matter in the Upper Jurassic limestone is mostly of marine origin. Particularly, the relation-ship of Hydrogen Index and S$_2$ as a function of Total Organic Carbon suggests that the upper formation of the core (Mornsheim Formation) was more influenced by terrigenous influx than the Solnhofen and Geisental Formations.

• Analytical Science and Technology
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• v.31 no.1
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• pp.7-13
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• 2018

In this study, we measured the time-resolved optically stimulated luminescence (TR-OSL) of Paleolithic paleosol quartz and evaluated its lifetime. Considering the lifetime dependence on the preheating applied after irradiation, the radiation exposure, and the optical pulse stimulation, we found that the optimum measurement condition for determining the lifetime of paleosol quartz was the optical pulse stimulation at a dwelling time of $250{\mu}s$, pulse width of $10{\mu}s$, and sweep number of 100,000, without preheating after 100 Gy of irradiation. Based on the dependence of the lifetime on the reading temperature, the thermal quenching activation energy ${\Delta}E$ and thermal assistance activation energy $E_a$ were evaluated as $0.60{\pm}0.14eV$ and $0.053{\pm}0.029eV$, respectively. These values were in good agreement with those reported in the literature. Therefore, we concluded that the resulting kinetic parameters for paleosol quartz are quite reliable.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.1
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• pp.27-33
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• 2024

In this study, we researched Ni-based bead catalysts for the catalytic thermal decomposition of light hydrocarbons. A Ni-based bead-type catalyst was prepared, and catalytic thermal decomposition performance of light hydrocarbons was evaluated. The 30Ni/Al₂O₃ catalyst exhibited the most superior performance, with the presence of both fibrous and carbon black forms on the catalyst surface. Catalytic performance was evaluated for particles sized between 150-250 and 500 ㎛, with excellent catalytic thermal decomposition properties in the 150-250 ㎛ range. After the reaction, carbon removal through collision between catalysts in the fluidized bed was observed. It was confirmed that as the particle size increases, the amount of carbon removed increases.

• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.407-414
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• 2016

Ex-situ catalytic pyrolysis of a Korean native oak tree over microporous zeolites (HZSM-5, HBeta, and HY) was performed by using a fixed bed reactor. The effect of sample to catalyst ratio and reaction temperature was also investigated to optimize production conditions of high quality bio-oil. Among three catalysts, HZSM-5 showed the highest aromatic formation due to its proper pore size and strong acidity. Although HY and HBeta also showed the catalytic activity, they produced larger amounts of coke due to their larger pore size. The smaller ratio of the sample to the catalyst and higher reaction temperature were also required to maximize the yields of aromatic hydrocarbons via the catalytic pyrolysis of oak tree over HZSM-5.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.140-143
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• 2011

산불의 확산형태 중 지표화 확산을 방지하기 위해 대표적인 진화방법으로는 방화선을 구축하는 것이다. 지표화는 산림의 연료중 낙엽층, 잔가지 등 지표면의 연료층이 열분해되면서 확산되기 때문에 방화선 구축을 통해 연료층을 제거하면 지표화 확산을 저지할 수 있다. 하지만 방화선 구축 폭에 따라 산불확산 방지 효과가 크게 달라질 수 있으므로 적정한 방화선 구축 폭을 설정하여야 한다. 본 연구에서는 적정 방화선 구축 폭을 살펴보기 위해 풍동시험장치를 이용하여 풍속 0, 1, 2, 3m/s조건에서 지표화 화염으로부터 이격 거리에 따른 온도측정과 함께 방화선 구축 폭에 따른 확산가능 여부를 평가하였다. 50cm 폭의 소나무 낙엽에 대한 풍속별 지표화 방화선 구축 실험결과, 풍속 3m/s에서 화염으로부터 소나무 낙엽의 착화온도인 $311^{\circ}C$에 도달하는 거리가 약 0.65m로 나타났고 풍속이 낮을수록 착화온도 도달거리가 줄어드는 것을 알 수 있다. 실제 0.6m 방화선 구축의 경우, 화염이 계속 확산되었고 0.65m 이상의 방화선 구축시에는 화염확산이 이루어지지 않았다. 따라서 향후, 수치해석을 이용한 열유속 평가 결과와 함께 본 연구의 실험결과와 비교평가 함으로써 지표화 산불확산 방지를 위한 적정 방화선 구축 폭 산정을 평가하고자 한다.

• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.208-213
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• 1998

Silicidation of the Co/Ti/Si bilayer system in which Ti is used as epitaxy promoter for $CoSi_2$has recently received much attention. The Co/Ti bilayer on the spacer oxide of gate electrode must be thermally stable at high temperatures for a salicide transistor to be fabricated successfully. In the $SiO_2$substrate was rapid-thermal annealed. The Sheet resistances of the Co/Ti bilayer increased substantially after annealing at $600^{\circ}C$, which is due to the agglomeration of the Co layer to reduce the interface energy between the Co layer and the $SiO_2$substrate. In the bilayer system insulating Ti oxide stoichiometric Ti oxide and silicide were not found after annealing.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.127-132
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• 1999

우리나라의 도시폐기물 소각로는 화격자 위에 폐기물을 공급하고 화격자 밑에서 공기를 공급하는 스토커식 소각로를 대부분 채택하고 있다. 이러한 스토커 소각로 연소실내에서는 매우 복잡한 연소현상이 발생하는데, 연소실로 투입된 쓰레기는 먼저 건조부에서 수분의 건조가 일어나고, 화격자의 구동에 의해 쓰레기가 혼합 및 이송되면서 열분해, 가스화, 가연성분의 탈휘발화 및 연소, 일부 고정탄소의 표면연소 등의 반응이 일어난다. 그리고 1,2차 연소실에서는 휘발분 및 비산된 고체의 연소가 일어나는데, 이때 대류 및 복사열전달 등의 복잡한 현상을 수반하는 유동장이 형성된다. 더욱이 불균질한 특성을 갖는 쓰레기층 내에서의 복잡한 현상으로 인하여 발생하는 경계조건 설정의 불확실성으로 연소실내의 연소 현상을 전산해석하는 데에는 상당한 어려움이 있다.(중략)

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.3
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• pp.260-268
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• 2019

The pyrolysis characteristics of pulverized coal particle was numerically analyzed with the drop tube furnace. Based on the simulated gas flow field in the drop tube furnace, the particle velocity, temperature and volatile evolution were calculated with the fourth order Runge-Kutta method. The effects of changes in reactor wall temperature and particle diameter on the pyrolysis behavior of coal particle were investigated. The particle heating rate was very sensitive to the reactor wall temperature and particle size, that is, the higher wall temperature and the smaller particle size resulted in the higher heating rate and the consequent quicker volatile evolution.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2006.09a
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• pp.33-37
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• 2006

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.05a
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• pp.196-202
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• 2005