• Korean Chemical Engineering Research
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• 제57권3호
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• pp.372-377
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• 2019

Leaching ($60^{\circ}C$, 5 min) and wet torrefaction ($200^{\circ}C$, 5 min) of empty fruit bunch (EFB) were carried out to improve the fuel properties; each liquid fraction was reused for leaching and wet torrefaction, respectively. In the leaching process, potassium was effectively removed because the leaching solution contained 707.5 ppm potassium. Inorganic compounds were accumulated in the leaching solution by increasing the reuse cycle of leaching solution. The major component of the leached biomass did not differ significantly from the raw material (p-value < 0.05). Inorganic compounds in the biomass were more effectively removed by sequential leaching and wet torrefaction (61.1%) than by only the leaching process (50.1%) at the beginning of the liquid fraction reuse. In the sequential leaching and wet torrefaction, the main hydrolysate component was xylose (2.36~4.17 g/L). This implied that hemicellulose was degraded during wet torrefaction. As in the leaching process, potassium was effectively removed and the concentration was accumulated by increasing the reuse cycle of wet torrefaction hydrolysates. There was no significant change in the chemical composition of wet torrefied biomass, which implied that fuel properties of biomass were constantly maintained by the reuse (four times) of the liquid fraction generated from leaching and wet torrefaction.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.337-338
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• 2014

In this study, a method of using a capacitance sensor was investigated as a means to measure the mass fraction of a type of harmful substance. Using MEMS process, we developed a capacitance sensor and studied the real time mass fraction with harmful substance mixture liquid.

• 한국대기환경학회지
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• 제23권4호
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• pp.457-465
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• 2007

This study was performed to estimate the gas-particle partitioning of organochlorine pesticides (OCPs) in atmosphere, the samples were collected by PUF high volume air sampler for two years from June, 2000 to June, 2002. The gas phase fraction of ${\alpha/\gamma}-HCH$, heptachlor epoxide, ${\alpha/\gamma}-chlordane$ and trans-nonachlor was over 90%. But the gas phase fraction of ${\beta}-HCH$, p,p'-DDE, endosulfan sulfate, p,p'-DDD and p,p'-DDT was range of 20% through 80%, which means the gas phase fraction of OCPs components described above is sensitive to temperature. The correlation between the gas phase fraction and molecular weight of each OCPs component was not found in this research. The slope of regression line between gas-particle partitioning coefficient(${\log}K_p$) and subcooled liquid vapor(${\log}{P^o}_L$), gal-particle partitioning coefficient(${\log}K_p$) and octanol-air partitioning coefficient(${\log}K_{oa}$) which show -0.54 and 0.43 was not steep. So the equilibrium state between gas and particle was not reached and in this state the particulate fraction was low.

• 설비공학논문집
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• 제13권4호
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• pp.304-311
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• 2001

An experimental study on the countercurrent two-phase flow in narrow rectangular channels has been performed. The void fraction and the pressure gradient were investigated using air and water in 760 mm long, 100 mm wide. vertical test sections with 2, 3 and 5 mm channel gaps. Tests were systematically performed with downward liquid superficial velocities and upward gas velocities covering 0 to 0.08 and 0 to 2.5 m/s ranges. respectively. the experimental results were compared with the previous correlations, which were mainly for round tubes, and the qualitative trends were found to be in good agreements. However the quantitative discrepancies were hardly neglected. as the superficial gas velocities increased, the void fraction increased and the pressure gradient decreased, where the effects of the liquid superficial velocities were infinitesimal. as the gap width of the rectangular channel increased the void fraction and the 2-phase frictional pressure gradient approached those values for the round tubes. Equi-periphery diameter, rather than the hydraulic diameter, seemed to be more effective in the analysis of two-phase flow behavior.

• KSBB Journal
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• 제19권5호
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• pp.381-384
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• 2004

The antimicrobial and antioxidative activities were investigated to confirm the utility of wood vinegar. Antimicrobial activity was performed by paper disc method and liquid culture. The growth inhibition was observed in all microbial species at a dose of as low as 25 $\mu$m of wood vinegar by paper disc method. Also, in liquid culture, S. cerevisiae and P. aeruginosa were more inhibited the growth than others in the concentration of $2\%$ (v/v). For measuring of antioxidative activity, wood vinegar was fractionated with acidic, phenolic, basic and neutral fraction; and their antioxidant activities were measured by the radical scavenging effect on DPPH radical. In four fractions, phenolic fraction showed high antioxidative activity.

• 약학회지
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• 제40권2호
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• pp.149-154
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• 1996

A high-performance liquid chromatographic method for the determination of ${\beta}$-sitosterol in the unsaponifiable fraction of Zea mays L. and its related drug preparations using a cholesterol as an internal standard was investigated. They were saponified with 20% methanolic KOH solution. Phytosterols in the reaction mixture were extracted with diethyl ether and separated on silica gel TLC plate with n-hexane-diethyl ether(40:60) as the solvent and then were scraped off. They were separated by reversed phase high perfomance liquid chromatography on Inertsil ODS-2 column with detection at 205nm. Cholesterol and ${\beta}$-sitosterol were resolved from interferences by adjusting the acetonitrile content in the MeOH-tetrahydrofuran-$H_2O$ eluent. The detection limit of ${\beta$-sitosterol was 0.43${\mu}$g.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.777-781
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• 1997

In this study, the effect of strain-rate and inital solid fraction on the deformation behaviour of semi-solid material is investigated, when semi-solid forging is performed by the process of closed-die compression using A356 alloy of which the above results can be practically applied for industrical purpose. In order to simulate densification in the deformation of semi-solid material, the semi-solid material is assumed to be composed of solid region following rigid visco-plastic material, the liquid region following Darcy's law for the liquid flow saturated in the interstitial space. Simulation results of closed-die compression and simple upsetting under different strain-rate and initial solid fraction are compared.

• Journal of Applied Biological Chemistry
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• 제44권2호
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• pp.77-83
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• 2001

For defining the possibilities of the commercial mass liquid culture of Cordyceps sinensis, the pharmacological activities of mycelia were analyzed. The mycelium of C. sinensis consists of carbohydrate (5.1%) and fat (1.3%), and contains a low content of protein (0.7%) and ash (0.5%), and 92.4% moisture. The molecular sugar ratio of carbohydrate was composed mainly of glucose, mannose (1.0 : 0.9), in addition a small amount of galactose and arabinose (0.2 : 0.1). The cellular materials of mycelia were fractionated into ethylacetate (EA), MeOH (M) and hot-water extract fraction (HW). HW fraction showed the most potent intestinal immune system modulating activity, anti-coagulant activity, and anti-complementary activity, and M fraction had the inhibition activity of radical generation as effective as genistine. These results reveal that the mycelium of liquid cultured C. sinensis showed pharmacological activities and could be used for commercial purpose.

• 신재생에너지
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• 제5권4호
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• pp.52-58
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• 2009

Upgrading of pyrolysis wax oil using HZSM-5 catalyst has been conducted in a continuous fixed bed reactor at $450^{\circ}C$, 1hour, LHSV 3.5/h. The catalytic degradation was studied with a function of catalyst amount and reaction temperature. The raw pyrolysis wax oil shows relatively high boiling point distribution ranging from around $300^{\circ}C$ to $550^{\circ}C$, which has considerably higher boiling point distribution than that of commercial diesel. The catalytic degradation using HZSM-5 catalyst shows the high conversion of pyrolysis wax oil to light hydrocarbons. The liquid product obtained shows high gasoline range fraction as around 90% fraction and considerably high aromatic fraction in liquid product. Here, the experimental variable such as catalyst amount and reaction temperature was influenced on the product distribution.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.234-237
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• 2008

It was reported that the semi-solid forming process has many advantages over the conventional forming process, such as a long die life, good mechanical properties and energy savings. It is very important, however, to control liquid segregation to gain mechanical property improvement of materials. During forming process, Rheology material has complex characteristics, thixotropic behavior. Also, difference of velocity between solid and liquid in the semi-solid state material makes a liquid segregation and specific stress variation. Therefore, it is difficult for a numerical simulation of the rheology Process to be Performed. General Plastic or fluid dynamic analysis is not suitable for the behavior of rheology material. The behavior and stress of solid particle in the rheology material during forging process is affected by viscosity, temperature and solid fraction. In this study, compression experiments of aluminum alloy were performed under each other tool shape. In addition, the dynamics behavior compare with Okano equation to Power law model which is viscosity equation.