• 청정기술
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• 제24권2호
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• pp.119-126
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• 2018

This study introduced a treatment process that was developed to treat Indonesian low-rank coal with high-ash content, which has the same characteristics as residual coal from the biosolubilization process. The treatment process includes separation of ash, solid-liquid separation, pelletizing, and drying. To reduce the ash content, flotation was performed using 4-methyl-2-pentanol (MIBC) as frother, and kerosene, waste oil, and cashew nut shell liquid (CNSL) as collectors. The increasing amount of collector had an effect on combustible coal recovery and ash reduction. After flotation, a filter press, extruder, and an oven drier were used to make a dried coal pellet. Then another coal pellet was made using asphalt as a binder. The compressive strength and friability of the coal pellets were tested and compared.

• 한국세라믹학회지
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• 제43권10호
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• pp.607-612
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• 2006

In VARTM (Vacuum Assisted Resin Transfer Molding) process, the permeability generally controls the filling time of the resin and it also affects the void characteristics of the fiber composite. In this study, carbon and glass fiber inter-layered hybrid composites (carbon fiber centered stack) with an epoxy matrix were fabricated by VARTM process and evaluated the resin flow and macro void characteristics. The permeability of glass fiber was higher than that of carbon fiber used in this study. Using Darcy's equation, the permeability of hybrid composites could be predicted and experimentally confirmed. After curing, the macro void content of hybrid composites was investigated using image analyzer. The calculated filling time was well agreed with experimental result and the void content was significantly changed in hybrid composites.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.436-438
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• 2009

To evaluate short rotation forestry candidates, seven clones of Salix hultenii were investigated as focused on chemical compositions and energy contents. There were significant variations in chemical compositions and energy contents among different clones. Variations in hot-water extractives content were 6.6-16.0% and 19.6-25.4% variation in lignin content. In carbohydrate compositional analysis, xylan contents were 7.5-13.1% with variation among different clones. Higher heating values were 17.69-20.02 MJ/kg.

• Nuclear Engineering and Technology
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• 제31권6호
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• pp.608-617
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• 1999

The powder mixture which has a bimodal size distribution, with a large mode corresponding to AUC-UO$_2$ powder and a small one corresponding to ADU-UO$_2$ powder, was prepared, pressed into compacts, and sintered at 1680t for 4 hours in hydrogen gas. The compact density of the powder mixture increases with increasing ADU-UO$_2$content within a content of 20 wt %, since small ADU-UO$_2$ particles can fill interstices between large AUC-UO$_2$particles. The UO$_2$ pellet made using the powder mixture has a lower open porosity than that made using AUC-UO$_2$ powder alone. The mechanism for the formation of a flake-like pore is proposed, and the decrease in open porosity may be ascribed to the decrease in the number of flake-like pores.

• Applied Biological Chemistry
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• 제35권6호
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• pp.449-456
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• 1992

인산처리가 근류의 bacteroid 함량과 energy 상태에 미치는 영향을 살펴보기 위하여 Bradyrhizobium japonicum MN10을 접종한 대두식물(Glycine max [L.] Merr.)에 저해농도(0.05 mM-P)와 정상농도(1.0 mM-P)를 처리하여 온실에서 재배하였다. 인산결핍은 식물체의 근류량과 근류량 식물체량의 비에 유의성있는 감소를 보였다. 잎, 줄기, 뿌리의 인산농도는 인산결핍에 의하여 75%가 감소하였으나 근류의 인산농도는 40%만 감소하였다. 근류의 bacteroid 함량과 근류에서 전인산, 전질소의 bacteroid와 식물세포로의 분배는 인산결핍의 영향을 받지 않았으며 전질소의 22%, 전인산의 27%가 bacteroid에 존재하였다. 근류의 ATP농도, 전 adenylate 농도와 energy charge는 인산결핍에 의하여 각각 77%, 46%, 37%가 감소되었다. 인산결핍은 근류내 식물세포의 ATP 농도와 energy charge를 각각 86%, 59%를 감소시켰으나 bacteroid의 ATP농도와 energy charge에는 영향을 미치지 않았다. 이러한 결과는 근류가 인산의 강한 보유원이며, 기주식물에 대한 인산결핍조건하에서 bacteroid는 정상적인 인산 농도와 energy양을 함유한다는 것을 나타낸다.

• 자원환경지질
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• 제22권2호
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• pp.141-150
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• 1989

In order to make economic and geological evaluation of coal in Korea, proximate and ultimate analyses were carried out as well as coal petrological studies such as maceral analyses, vitrinite reflectance and sporinite fluorescence measurement. The coeffcient of correlation between each factor of both conventional utilization and coal petrological parameters were studied as in Table 5 and 6. Their conclusions were as follow: (1) for anthracite, the good parameters of coal rank are mean vitrinite reflectance, carbon content, hydrogen content and H/C atomic ratio: (2) for brown coal and sub-bituminous coal, the good parameters of coal rank are carbon content, calorific value, moisture content, hydrogen content, oxygen content and O/C atomic ratio as well as vitrinite reflectance and sporinite fluorescence. An attempt is made to infer the coalforming environment by utilization of coal petrological analyses and to make comparison of coal analyses with proximate and ultimate analyses throughout the island arc region including Japan, Philippine and Indonesia and continental region including USA, Canada and Australia. As a result, meceral composition of Paleozoic and Mesozoic anthracite are similar to that of the Paleozoic continental coals, which were formed under dry conditions or low water table, but the coalification degree suddenly increased during Daebo orogeny (middle Jurassic to lower Cretaceous). The Tertiary coal resembles those of Tertiary island arc region coal characterized by higher calorific value, volatile matter content and H/C atomic ratio and by the formation of coal under wet conditions or higher water table.

• 한국전기전자재료학회논문지
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• 제17권12호
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• pp.1326-1331
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• 2004

In this paper, we have investigated thermal properties and Impurities content of specimens showing by changing the content of carbon black that is semiconductive materials for underground power transmission. Specimens were made of sheet form with the three of existing resins and the nine of specimens for measurement. Impurities content of specimens was measured by ICPAES(Inductively Coupled Plasma Atomic Emission Spectrometer). Heat capacity(ΔH) and melting temperature(Tm) were measured by DSC(Differential Scanning Calorimetry). The ranges of measurement temperature were from $0^{\circ}C$ to 20$0^{\circ}C$, and heating temperature was 4$^{\circ}C$/min. And then thermal diffusivity was measured by LFA 447. The measurement temperature was $25^{\circ}C$. Impurities content was highly measured according to increasing the content of carbon black from ICPAES results. And heat capacity and melting temperature from the DSC results were simultaneously decreased according to increasing the content of carbon black, while thermal diffusivity was increased according to increasing the content of carbon black. Because ionic impurities of carbon black containg Fe, Co, Mn, Al, and Zn were rapidly increasing kinetic energy by vibration of ionic impurities through the applied heat energy.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권9호
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• pp.455-458
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• 2004

In this paper, we investigated impurities content and physical properties showing by changing the content of carbon black that is semiconductive materials for underground power transmission. Specimens were made of sheet form with the three of existing resins and the nine of specimens for measurement. Impurities content of specimens was measured by ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometer), and density of specimens were measured by density meter And then specific heat (Cp) was measured by DSC (Differential Scanning Calorimetry). A ranges of measurement temperature were from $0^{\circ}[C]$ to $200^{\circ}[C]$, and heating temperature was $4^{\circ}[C/min]$. Impurities content was highly measured according to increasing the content of carbon black from this experimental result, also density was increased according to these properties. Especially impurities content values of the Al and A2 of existing resins were measured more than 4000［ppm］. Specific heat from the DSC results was decreased according to increasing the content of carbon black. Because ionic impurities of carbon black having Fe, Co, Mn, Al and Zn are rapidly passed kinetic energy increasing the number of times breaking during the unit time with the near particles according to increasing vibration of particles by the applied heat energy.

• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.3095-3097
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• 2009

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2011년도 추계학술논문요약집
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• pp.123-124
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• 2011