• Fire Science and Engineering
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• v.33 no.6
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• pp.95-104
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• 2019

Smoke generated in a fire consists of gaseous substances and particulate matter, such as unburned carbon that adsorbed the gases. Human injury caused by inhalation of gaseous substances present in smoke is mostly short-term, whereas damage caused by inhalation of particulate matter is relatively a long-term phenomenon depending on the state of the gas-phase adsorption. The amount and location of the deposited smoke particles are important factors in estimating the damage caused to humans, which are affected by the breathing conditions as well as particle conditions, such as the size and concentration affected by the combustion conditions. In this study, in order to understand the characteristics of the deposition of smoke particles in the respiratory tract related to the study of human smoke inhalation injury, the number and mass concentration of smoke particles deposited in different areas of the respiratory tract for different fuel types, combustion conditions and breathing conditions were calculated. In addition, the amount of mass deposition of smoke in the respiratory tract for a certain period of inhalation was compared with the atmospheric standard of fine dust.

• Analytical Science and Technology
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• v.10 no.3
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• pp.179-186
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• 1997

This study was carried out to improve the analytical method for determination of germanium in plants by atomic absorption spectrometry with graphite furnace. For the decomposition of plant samples, the mixed acid of $HNO_3+HClO_4+H_2SO_4$(10 : 4 : 1, v/v) was used. Under this condition, time requirement for the decomposition was 4~5 days and recovery rate was more than 98%. Solution for filling up to constant volume after decomposition was 0.1M acetic acid-sodium acetate. Detection limit for determination of germanium was 0.02 ppm by atomic absorption spectrometry with graphite furnace and argon gas. These results were corresponded with the above-mentioned research projects for improving the determination method of germanium in plants.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.97-97
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• 2015

전 세계적으로 화석연료의 고갈 및 환경오염 문제를 해결하기 위해 신재생에너지에 대한 관심이 급증하고 있다. 이러한 신재생에너지에는 수소 에너지, 자연 에너지(태양열, 지열 등), 바이오 매스 에너지 등이 포함된다. 이 중 수소 에너지는 지구상에 풍부하게 존재하고 있는 물과 탄화수소로부터 얻어지며, 연소 시에도 다시 물을 형성하여 오염 물질을 배출하지 않는 차세대 무공해 에너지원으로써 주목을 받고 있다. 수소 제조를 위한 공정에는 수증기 개질 공정(steam reforming), 부분 산화(partial oxidation) 및 자열개질(autothermal reforming) 등이 있으며 실제로 생산되는 대부분의 수소는 탄소/수소비(1:4)가 높은 메탄($CH_4$) 가스를 이용한 메탄 수증기 개질 공정(steam methane reforming)을 통하여 제조된다. 이 때 수소 제조의 고효율화 및 저비용화를 위해서는 반응물에 대한 높은 선택도, 고활성도 및 높은 안정성을 갖는 촉매가 반드시 필요하며, 대표적으로 Ni, Pt, Ru 등이 보고되고 있다. 이러한 촉매들은 대부분 세라믹 pellet 형태로 제작되어 왔으나 열전도도가 낮고 물리적 충격에 취약하다는 단점이 존재한다. 따라서 우리는 이러한 단점을 극복하고, 촉매의 활성을 높이기 위하여 다공성 금속 합금 폼을 촉매 지지체로 도입하였다. 또한, 다공성 금속 합금 폼 표면에 촉매의 분산 및 안정성을 향상시키기 위해 지지체와 촉매 사이에 원자층 증착법을 이용하여 inter-layer를 도입하였다. 이들의 구조, 형태, 및 표면의 화학적 상태는 주사전자현미경, EDS (energy dispersive spectroscopy)가 탑재된 주사전자현미경, X-선 회절, 및 X-선 광전자 분광법을 이용하여 규명하였다. 더하여 정전압-전류 측정법 및 유도 결합 플라즈마 분광 분석기을 이용하여 전기 화학 반응을 유도하고, 반응 후 전해질의 성분분석을 통해 촉매와 지지체 간의 안정성을 평가하였다. 따라서 본 결과들은 한국진공학회 하계정기학술대회를 통해 좀 더 자세히 논의될 것이다.

• Korean Journal of Materials Research
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• v.21 no.3
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• pp.138-143
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• 2011

Nanosized Pt, Pt-Ru and Pt-$CeO_2$ electrocatalysts supported on acid-treated carbon nanotube (CNT) were synthesized by microwave-assisted heating of polyol process using $H_2Cl_6Pt{\cdot}6H_2O$, $RuCl_3$, $CeCl_3$ precursors, respectively, and were characterized by XRD and TEM. And then the electrochemical activity of methanol oxidation for catalyst/CNT nanocomposite electrodes was investigated. The microwave assisted polyol process produced the nano-sized crystalline catalysts particles on CNT. The size of Pt supported on CNT was 7~12 nm but it decreased to 3~5 nm in which 10wt% sodium acetate was added as a stabilizer during the polyol process. This fine Pt catalyst particles resulted in a higher current density for Pt/CNT electrode. It was also found that 10 nm size of PtRu alloys were formed by polyol process and the onset potential decreased with Ru addition. Cyclic voltammetry analysis revealed that the $Pt_{75}Ru_{25}/CNT$ electrode had the highest electrochemical activity owing to a higher ratio of the forward to reverse anodic peak current. And the chronoamperemetry test showed that $Pt_{75}Ru_{25}$ catalyst had a good catalyst stability. The activity of Pt was also found to be improved with the addition of $CeO_2$.

• Journal of the Korean Institute of Gas
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• v.10 no.3 s.32
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• pp.60-64
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• 2006

Explosion range and explosion characteristics of by product gas from carbon black manufacturing process were studied. About 75% of the by product gas were composed with water vapour and nitrogen. And the combustible component in the gas were hydrogen, methane, acetylene and carbon mono-oxide. Because of the combustible components in the by product gas there are explosion hazards in the gas handling process. Explosion range of the gas by experiment was from 17.1% to 70.7% and the value has considerable difference with the calculated value from Lechatelier law. Explosion pressure of the gas was $5.4kg/cm^2$ and the average explosion pressure rise rate was $39.2kg/cm^2/s$. Based on the experimental result we can expect that a explosion or fire accident during the handling the gas can make a severe loss, therefore there should be a explosion prevention or protection measures in the gas handling process.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.176.2-176.2
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• 2011

피마자유(Castor oil)는 합성수지, 그리스, 유압용 오일, 윤활기유 등의 다양한 용도로 쓰이는 오일로서 점도가 높고 무색에서 황갈색을 띈다. 피마자유 추출은 압착 착유 또는 용매 추출로 얻게 되며 본 실험에 사용된 오일은 압착 착유한 것으로 매우 진한 갈색을 띄는 정제전 오일을 이용하였다. 실험에 사용된 피마자유의 초기 산가는 1mgKOH/g 이하로 낮은 유리지방산 함량을 보였으며 수분은 0.3%로 전이에스테르화 반응을 위해서는 수분 증발이 필요했다. 피마자유의 바이오디젤 생산을 위해 진행된 물성 분석 항목은 산가, 수분, 인함량, 황함량, 점도, 고형물이며 원료유와 그 바이오디젤에 대해 각각 물성 분석을 실시하였다. 피마자유의 가장 큰 특징은 다른 식물성 오일과는 다르게 오일이 알코올에 녹는 특성이 있으며 이런 이유로 전이에스테르화 반응 후 바이오디젤과 글리세롤이 분리되지 않는 문제점을 갖고 있다. 피마자유를 이용해 제조한 바이오디젤, 즉 지방산메틸에스터의 함량을 분석한 결과 약 90%의 메틸에스터화 반응 전환율을 나타내었으나 국내외 품질규격상의 탄소수 C14~C24:0의 지방산 에스터(fatty acid methyl esters)로 검출되는 바이오디젤의 함량은 10% 미만으로 나타났으며 나머지 90%는 라이신올레익산메틸에스터(ricinoleic acid methyl ester)로 분석되었다. 따라서, 기존의 대두유, 유채유, 팜유, 폐식용유로부터 제조한 바이오디젤과 물성이 매우 상이하고 특히 끊는점(boiling point)과 점도가 높아 경유 대체연료로는 활용이 불가능할 것으로 판단된다. 하지만 기존의 다양한 용도의 오일로 사용하기 위해 정제하는 과정에서 전체 착유 오일중의 약 10%만을 선택적으로 분리하여 바이오디젤 원료로 활용하는 방안은 가능할 것으로 판단된다.

• Elastomers and Composites
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• v.46 no.2
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• pp.118-124
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• 2011

Recently, the need of new materials which have excellent physical properties and functional characteristics has been increased in all industries. In particular, body weight reduction via new materials in aerospace industry was significantly emphasized by the requirement of environmental protection through the fuel savings and reduction of greenhouse gas, i.e., carbon dioxide($CO_2$). Also, for various applications, the development of high performance custom materials with excellent physical properties was the current primary goal of materials science and technology. In this respect, carbon fiber-reinforced composites were the most candidates among the various materials. Indeed, carbon fiber-reinforced composites have been lately used as essential materials for the weight reduction of aircraft and the demand has increased remarkably. Therefore, in this paper, we focused on the need of carbon fiber composites in the fields of aircraft and technique status.

• Journal of Korea Foresty Energy
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• v.18 no.1
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• pp.37-45
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• 1999

The greenhouse effect becomes the most serious environmental problem due to excessive emission of carbon dioxide. This effect is aggravated with the deforestation, particularly cleaning of tropical forest for agricultural use. As trees sequester carbon dioxide from atmosphere, forest and forest products play an important role in the use and reduction of carbon dioxide. Wood and wood products require far less energy than the alternatives such as steel, aluminium and concrete for production. Considering high probability of increasing costs in the use of fossil fuel, the relatively low energy requirement for wood processing to very important. Also wood and wood products perform as a long-term storage of carbon. Wood is therefore an environmentally desirable resource. Recently, many alternatives have been introduced for industrial use. In selecting resources, many aspects should be taken into consideration. Wood and wood products have less harmful effects on the environment than the alternatives. We should utilize wood and wood products more efficiently, which should be provided based on the sustainable forest management.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.4
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• pp.485-490
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• 2010

MILD (Moderate and Intense Low Oxygen Dilution) combustion is a technique which is able to reduce NOx formation and to uniform temperature distribution in the furnace by recirculating the exhaust gas to the fresh air and fuel. This study focuses on finding optimal condition of MILD combustor by changing equivalence ratio with fuel and air flow. The present experiment employs six thermocouple sensors in the furnace, and two concentration probes of NOx and CO at the exhaust exit pipe respectively. The MILD combustion phenomena have been observed at the condition of equivalent ratios of 0.71~0.73, and the temperature uniformity, NOx and CO concentration are also examined at the MILD combustion condition.

• Journal of the Korean Wood Science and Technology
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• v.39 no.6
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• pp.512-520
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• 2011

This study was preformed to investigate the characteristics of the green drying system for utilizing heat wasted during carbonization process. The green drying system utilizing waste heat is one of environment-friendly equipments because it needs no other energies from fossil fuel and etc. In this study, waste heat from three kilns was collected by stainless connection pipe, and in the green drying system the temperature and humidity was hardly changed. Charcoal charecteristics as fixed carbon, refining degree, hardness, pH, calorific value, and charcoal yield were analyzed to investigate kiln performance due to installation of green drying system. As a result, the green dry system installation hardly affected the characteristics of charcoal. In conclusion, the green drying system can be applied to maximize the profit of the farm household income and contribute to reduce fossil energy.