• 대한화학회지
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• 제13권2호
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• pp.187-193
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• 1969

As part of an extensive program on the microbiological oxidation of hydrocarbons, reaction conditions and nutrients consumption of candida lipolytica grown on alkane as carbon source were studied. For optimum growth of yeast, the conditions of pH 5, temperature $30^{\circ}C$, carbon number $C_{16}$& $C_{18}$aeration 25.6 1/l/hr, agitation 3000 r.p.m., hydrocarbon concentration 10% were obtained. Carbon and nitrogen balance related to these conditions were also investigated. In the course of this investigation, some significant effects of pH and carbon number of hydrocarbon variation were observed.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.718-722
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• 1998

Scopoletin (7-hydroxy-6-methoxycoumarin), a coumarin, was isolated from the aerial part of Solanum lyratum Thunb. by the activity-guided fractionation employing carbon te trachloride-intoxicated primary cultured rat hepatocytes as a screening system. Its hepatoprotective activity was first evaluated by measuring the release of glutamic pyruvic transaminase and sorbitol dehydrogenase from carbon tetrachloride-intoxicated rat hepatocytes into the culture medium. Scopoletin significantly reduced the releases of glutamic pyruvic transaminase and sorbitol dehydrogenase from the carbon tetrachloride-intoxicated primary cultured rat hepatocytes by 53% and 58%, respectively, from the toxicity in a dose-dependent manner over concentration ranges of 1mcM to 50mcM. Further studies revealed that at the concentration of 10mcM, scopoletin significantly preserved glutathione content by 50% and the activity of superoxide dismutase by 36% and also inhibited the production of malondialdehyde to the degree as seen in the control.

• 한국항만학회지
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• 제14권3호
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• pp.373-378
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• 2000

Oil spill in sea water is the most frequent and significant problem of marine pollution. As an early detection sensor of the pollution, an activated carbon coated quartz crystal is prepared and examined for its performance of detection sensitivity and stability. Powdered activated carbon and phenol resin is coated on the surface of the sensor and the sensor is baked for an hour. Adsorption of acetone dissolved in water and salt water is measured using frequency shift of quartz crystal at different concentrations of solute material. The outcome indicates that the sensor preparation is adequate and the measurement of solute concentration is stable and sensitive enough to be implemented on the monitoring of solute concentration is stable and sensitive enough to be implemented in the monitoring of organic pollution of sea water.

• 한국표면공학회지
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• 제33권2호
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• pp.69-76
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• 2000

The rf plasma chemical vapor deposition is a common method employed for diamond or amorphous carbon deposition. Diamond possesses the strongest bonding, as exemplified by a number of unique properties-extraordinary hardness, high thermal conductivity, and a high melting tempera tore. Therefore, it is very important to investigate the synthesis of semiconducting diamond and its use as semiconductor devices. An inductively coupled rf plasma CVD system for producing amorphous carbon films were developed. Uniform temperature and concentration profiles are requisites for the deposition of high quality large-area films. The system consists of rf matching network, deposition chamber, pumping lines for gas system. Gas mixtures with methane, and hydrogen have been used and Si (100) wafers used as a substrate. Amorphous carbon films were deposited with methane concentration of 1.5% at the process pressure of S torr~20 torr, and process temperature of about $750^{\circ}C$. The nucleation and growth of the amorphous carbon films have been characterized by several methods such as SEM and XRD.

• 한국환경과학회지
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• 제19권12호
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• pp.1403-1407
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• 2010

The adsorption characteristics of $CO_2$ gas on impregnated activated carbons with MEA (Mono-ethanolamine) and AMP (2-Amino 2-methyl 1-propanol) were studied to improve the adsorption ability of $CO_2$ gas on activated carbon. The equilibrium adsorption capacity of $CO_2$ gas was increased by increment of impregnation concentration up to 40 %, but decreased above 50 %. The adsorption capacity of activated carbon impregnated with AMP was higher than activated carbon impregnated with MEA. The breakthrough was fast according to increment of inlet concentration of $CO_2$ gas.

• 한국대기환경학회지
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• 제17권3호
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• pp.269-276
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• 2001

The objective of this study was to investigate the biodegradation of ethylene in an biofilter inoculated with ethylene-oxidizing microorganisms. The biofilter performance was monitored in terms of ethylene removal efficiency and carbon dioxide production. The biofilter was capable of achieving the ethylene removal efficiency as much as 100% at a residence time of 14 min and an inlet concentration of 290 ppm. Under the same conditions, carbon dioxide with a concentration of up to 546 ppm was produced. It was found that carbon dioxide was produced at a rate of 87 mg/day, which corresponded to a volume of 0.05 L/day. Observable features of the ethylene-oxidizing microorganisms, meaning microbial activity occurrence in the biofilter, were investigated with the microscopy analysis.

• 한국안전학회지
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• 제15권4호
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• pp.88-94
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• 2000

The adsorption characteristics of Tharonil on granular activated carbon were experimentally investigated in an adsorber and in a packed column. It was estabilished that the adsorption equilibrium of Tharonil on granular activated carbon was more successfully fitted by Freundlich isotherm equation than Langmuir isotherm equation in the concentration range from 1 to 1000 mg/1. Intraparticle diffusivities (pore and surface diffusivity) of Tharonil were estimated by the concentration-time curve and adsorption isotherm. The estimated values of pore diffusivity and surface diffusivity are $6.70{\times}10^{-6}$ and $2.0{\times}10^{-9}cm^2/s$, respectively. From comparison of intraparticle diffusivities, it was found that surface diffusion was the limiting step for adsorption rate. The break time and breakthrough curve predicted by constant pattern-linear driving force model were shown to agree with the experimental results.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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• pp.290-293
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• 2008

In this study, the Computational Fluid Dynamics (CFD) has been used to analyze the smoke movement and the carbon monoxide concentration distribution, both vertically and longitudinally, in a compartment, based on conservation laws. The Fire Dynamics Simulator (FDS) developed by National Institute of Standards and Technology (NIST) was used for numerical simulations using Reynolds averaged Navier-Stokes equations (RANS) model to solve for time-averaged properties. Results show, as a function of time, a detailed distribution of temperature and carbon monoxide concentration changing against the height above the floor and those changes alongside the distance away from the fire source. Fire-induced smoke and toxic gases like CO are more dangerous in a confined space. The result of study may contribute in designing the smoke evacuation system based on the precise tenable condition.

• Carbon letters
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• 제1권2호
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• pp.87-90
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• 2000

Porous carbon from charcoal filled polypropylene composites were prepared and their mechanical properties were evaluated. In preparing the composites, crosslinking agent (sodium benzonate) were used in order to improve the bonding force between matrix and fillers. In this study, the effects of charcoal powder and sodium benzonate concentration on the mechanical properties and interface phenomena on the composites were evaluated. The mechanical properties of composites increased progressively with the decrease of filler loading. In the case of addition of the crosslinking agent into the composite, the mechanical properties were increased and showed maximum value at the 3 wt% concentration of sodium benzonate. According to the result of the TGA, the weight loss of composite according to crosslinking agent was not observed and initial thermal degradation temperature of composite reinforced charcoal was located at $390^{\circ}C$.

• 한국해양환경ㆍ에너지학회지
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• 제11권3호
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• pp.124-131
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• 2008

2003년 8월과 2004년 9월 제주도 남서부해역과 중국 연안해역을 대상으로 실시된 본 연구는 용존무기영양염류와 용존 및 입자유기탄소의 분포 특성을 조사하였다. 하계에 동중국해의 영양염의 분포 형태는 수괴 및 식물플랑크톤의 영향을 받은 것으로 밝혀졌다. 하계에 동중국해내 수괴들은 중국의 연안해역을 제외하고 상하수직혼합이 잘 일어나지 않아 표층수에는 영양염의 유입이 감소하고, 저층수에는 표층에서 유입되는 유기물이 분해되어 영양염의 축적이 일어나 높은 농도를 나타내고 있었다. Chlorophyll a의 농도가 높은 해역에서 영양염의 농도가 낮은 값을 보였으며, Chlorophyll a의 농도가 감소하는 수심이하에서 영양염의 농도가 증가함을 보여 높은 생물활동에 의한 무기영양염류 등이 조절되고 있는 것으로 생각된다. 연구해역내 용존유기탄소의 분포는 염분이나 수온에 대해 다소 산만한 분포를 보여 수괴에 따른 상관관계가 없는 것으로 조사되었고, 양자강 영향 정점에서 $100{\mu}M$이상의 높은 값을 보인 반면, 제주도 남서부 해역에서는 낮은 농도를 보였는데, 이것은 양자강 유출수가 동중국해 용존유기탄소의 공급원으로 작용하고 있는 것으로 사료된다. 연구해역 입자유기탄소의 분포특성은 양자강 유출수가 영향을 미치는 중국연안해역에서 평균 $9.23{\mu}M$로 가장 높은 농도를 보였으며, 대마난류수의 영향을 받는 제주도 남동부해역에서 $3.04{\mu}M$로 낮은 농도를 보였으며, 중앙부해역에서 $7.23{\mu}M$의 입자유기탄소량을 나타내, 양자강 유출수가 자생적 기원이외의 입자유기탄소 공급원으로 작용하고 있는 것으로 사료된다. 제주도 남서부해역에서의 입자유기탄소는 Chlorophyll a의 농도와 높은 상관성을 보여 자생적 기원으로 볼 수 있지만 그 해역에서의 염분도가 저염(30%o 이하)을 나타내고 있어 자생적 기원보다는 육상기원에 의한 영향으로 생각되어진다.