• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.224-228
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• 2015

The carbon precursor pitch from pyrolyzed fuel oil (PFO), by-product of Naphta cracking process (NCC), was prepared through heat and UV irradiation treatments with various concentrations of $AlCl_3$, which is a new pitch preparation method. The reformed pitches were characterized by measuring their elemental composition, chemical structure of components, molecular weight distribution, and softening point. The oxygen contents of reformed pitch increased as increasing $AlCl_3$ amounts on the other hand, the carbon and hydrogen contents were not nearly changed. UV irradiated reformed pitches were composed of more aromatic carbon compounds than that of using only heat-treatment without any UV irradiation. The addition of $AlCl_3$ catalyst was ineffective on the aromaticity of reformed pitches. The softening point of prepared pitches was in the range of $103.3{\sim}168.9^{\circ}C$. Also the yield of prepared pitch increased from 48% to 80% when 5 wt% of $AlCl_3$ was added during the heat and UV irradiation reforming. It is expected that the UV irradiation reforming method can be practical and helpful to produce high yields of pitches with diverse properties.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.263-273
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• 2019

South Korea's OF cable is reaching its expected design life of 30 years, and as a result, the risk of failure is increasing. Therefore, it is necessary to diagnose the long-term operating OF cables through accurate diagnosis at the right time to prevent the failure. Currently, the KEPCO periodically conducts DGA. However, the gas found in DGA is caused by oil deterioration as well as insulation paper. Therefore, the analysis of the degree of polymerization and furan compounds which is an evaluation of insulation paper considered to be the life of OF cables is required. In addition, the results of the evaluation of deterioration of insulation paper need to be checked for correlation with the results of DGA. In this study, DGA carried out through GC, the degree of polymerization was analyzed using an automatic viscometer, and HPLC was used to detect the furan compounds. In addition, the obtained results were applied to the SVM technique, which was recently introduced to determine abnormalities in OF cable. And the results which were accurate and reliable were obtained.

• Food Science and Preservation
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• v.21 no.3
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• pp.421-426
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• 2014

In this study, the antioxidant and pancreatic lipase inhibitory activities of aqueous methanolic (70% methanol) extract from the roots of Anemarrhena asphodeloides were investigated. The extracts of four solvent fractions (the n-hexane layer, EtOAc layer, n-BuOH layer, and $H_2O$ layer) of the 70% methanol extract were also investigated. Furthermore, the total phenolic content was quantified using a spectrophotometric method. All the tested samples showed dose-dependent radical scavenging and pancreatic lipase inhibitory activities. In particular, the pancreatic lipase inhibitory activity of the ethyl acetate soluble portion (the EtOAc layer) from the rhizomes of the A. asphodeloides was higher than that of the other solvent-soluble portions. The antioxidant property of the extracts was evaluated using radical scavenging assays with DPPH and $ABTS^+$ radicals. 1000 mg/ml of the n-BuOH layer extract showed 91.2% DPPH radical scavenging activity. The EtOAc layer extract and the n-BuOH layer extract showed $IC_{50}=20.5{\pm}1.7mg/ml$ and $IC_{50}=50.5{\pm}0.7mg/ml$ $ABTS^+$ radical scavenging activities, respectively. The anti-obesity efficacy of the A. asphodeloides extract was tested via porcine pancreatic lipase assay. A pancreatic lipase inhibitory activity ($IC_{50}$) of $31.3{\pm}0.1mg/ml$ was obtained from the EtOAc layer extract. These results suggest that A. asphodeloides can be considered a new potential source of natural antioxidant and anti-obesity agents.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.3
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• pp.127-138
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• 2016

Diesel vehicles should be equipped with urea-selective catalytic reduction(SCR) system as a high-performance catalyst, in order to reduce harmful nitrogen oxide emissions. In this study, a three-dimensional Eulerian-Lagrangian CFD analysis was used to numerically predict the multiphase flow characteristics of the urea-SCR system, coupled with the chemical reactions of the system's transport phenomena. Then, the numerical spray structure was modified by comparing the results with the measured values from spray visualization, such as the injection velocity, penentration length, spray radius, and sauter mean diameter. In addition, the analysis results were verified by comparison with the removal efficiency of the nitrogen oxide emissions during engine and chassis tests, resulting in accuracy of the relative error of less than 5%. Finally, a verified CFD analysis was used to calculate the interanl flow of the urea-SCR system, thereby analyzing the characteristics of pressure drop and velocity increase, and predicting the uniformity index and overdistribution positions of ammonia.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.85-100
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• 2010

Devonian Cairn Formation is one of the important hydrocarbon reservoirs in Alberta, Canada. However, the Cairn Formation, outcropped in the study area, is not prospective reservoir with poor porosity and permeability by some late diagenetic processes. In this study, geochemical characteristics of the Cairn Formation were studied to use these preliminary results for advanced geological and geophysical petroleum explorations in the near future. Rock-Eval pyrolysis showed that total organic carbon content is less than 0.3 wt.%, indicating a minor amount of bitumen and/or other hydrocarbons. The carbonates in the Cairn Formation are mainly composed of subhedral and anhedral dolomites. Pore sizes in the carbonate are various, ranging from nanometer to micrometer. Clastic sediments increase in the upper and lower parts of the Cairn Formation, probably due to changing its depositional conditions. The Cairn Formation can also be divided into several intervals based on Ca/Mg ratio in dolomite and degree of amount of calcite. These could be formed by different sedimentary environment, degree of cementation and recrystallization, different saline/fresh water, etc.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.137-147
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• 1999

Fluidized-bed thermal desorber coupled with a heat pipe was investigated for the remediation of soil contaminated with diesel oils. Thermal gravimetric analysis by Cahn-balance indicated that the desorption of diesel oils from the soil particles was mainly governed by the internal diffusion at low concentration of less than 0.5 wt. % of oils in the soil particles. In fluidized-bed experiments. increase of fluidizing gas velocity reduced the residual oils of the contaminated soils, the increase of soil feed rate decreased efficiency of fluidized-bed desorber. A mathematical model was developed by incorporating Fickian diffusion kinetics into the Kunii-Levenspiel model Simulation results showed reasonable agreement for the performance of fluidized-bed thermal desorber.

• Journal of Nutrition and Health
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• v.46 no.6
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• pp.521-530
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• 2013

Protein-energy malnutrition, PEM, and increased hs-CRP level are considered to be associated with increased risk of cardiovascular disease (CVD) in hemodialysis (HD) patients. This is commonly referred to as the vicious circle of malnutrition-inflammation-atherosclerosis cardiovascular disease (MIA syndrome) in chronic kidney disease (CKD). Low protein intake can decrease the serum level of albumin and increase inflammational markers; further, both low serum albumin and high hs-CRP are independent risk factors for all-cause mortality in HD patients. The aim of this study is comparing the serum levels of albumin and hs-CRP in HD patients according to the protein intake levels. The total number of subjects was 60 hemodialysis patients; they were grouped by dietary protein intake: low protein intake group (LPI, protein intake < 1.0 g/kg IBW, 11 men and 19 women) and adequate protein intake group (API, protein intake ${\geq}$ 1.0g/kg IBW, 12 men and 18 women). Blood biochemical parameters, nutrient intake, and dietary behaviors were compared between the LPI and API groups. The LPI group showed a significantly lower serum level of albumin and higher serum level of hs-CRP than the API group (p < 0.05). The LPI group showed a significantly lower intake of most nutrients than the API group (p < 0.05). Index of Nutritional Quality of most nutrients of the LPI and API groups were lower than 1.0. Dietary protein intake was positively correlated with the serum level of albumin (r = 0.306, p < 0.05) and negatively correlated with the serum level of hs-CRP (r = -0.435, p < 0.01). The serum level of hs-CRP was negatively correlated with that of albumin (r = -0.393, p < 0.01). According to these result, serum albumin and hs-CRP in HD patients were influenced by the protein intake levels. To prevent MIA syndrome, it is necessary to improve nutritional status, especially in protein and energy.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.373-378
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• 1991

The skin and fleshy substance on the net fiber of sponge-gourd fruit pressed mechanically was removed with 0.2% NaOH solution in $3{\sim}5$ hours. The treatment of 0.2% NaOH with 0.02% Monopol(non-ionogenic polyoxethylen derivative) as surfactnat and with 0.1% $Ca(OCl)_2$ as bleaching agent enhanced the effect to remove the fleshy substance and improve the quality of net fiber. Also, the wet hardness and tensile strength of net fiber were controlled by the crosslinkage of the fiber with glu tardialdehyde, glyoxal, and formalin, respectively. The net fiber was stable on the acid and alkaline solutions. Also the range of temperature to degradate the fiber was $338{\sim}385^{\circ}C$. These values indicated a fair stability. The improved net fiber can be used for raw material of bath, dish washing, oil and gas filter, and many kinds of decorations.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.227-233
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• 2016

This study was designed to analyze the chemical compositions of 'Setoka' branch essential oils (SEBO) and to test their biological activities. 'Setoka' is a Citrus species widely cultivated in Jeju Island. At the present, 'Setoka' branches produced by thinning process were mostly discarded as a waste. Therefore, utilization of this branch waste has received much attention. 'Setoka' branch essential oils (SBEO) were prepared by treatment of its ethanol extracts with jojoba oil. SBEO were chemically analyzed using gas chromatograph-mass spectrometry (GC-MS), and following components were identified; ethyl linoleate (64.14%), ethyl palmitate (16.50%), neophytadiene (11.06%) and beta-citronellol (5.09%). The anti-inflammatory activity in the SBEO was examined using RAW 264.7 murine macrophage cells stimulated with LPS. As a result, the SBEO inhibited nitric oxide (NO) productions with a dose-dependent manner. In addition, SBEO showed good anti-microbial activities against drug-susceptible and -resistant skin pathogens such as Staphylococcus aureus and Propionibacterium acnes, which are acne-causing bacteria. Based on these results, we suggest that SBEO has the possibility for use as an anti-inflammatory and anti-microbial agent in cosmetic applications.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.232-240
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• 2012

Bio-diesel (BD) is the mono alkyl esters of long chain fatty acids derived from renewable feed stocks like vegetable oils or animal fats. Bio-diesel shows poorer fuel properties than that of diesel fuel in a cold condition. For the diesel fuel, many cold flow improvers have been developed; however, since primary ingredients of bio-diesel are different from those of the diesel fuel, there is a limit to the cold flow improvement when the same cold flow improvers are added to bio diesel. In this study, to improve low temperature properties of bio-diesel, we developed a cold flow improver using an alkyl methacrylate monomer, prepared via ester reaction, and maleic anhydride and also conducted a ring opening reaction using amine. We characterized the products using $^1H-NMR$, FT-IR and GPC methods. In addition, the cold flow improvements of the products in Soybean BD and Palm BD in the concentration rage of 1000~10000 ppm were investigated. It was found that the addition of LMA2SMA6MA2-C8A in Soybean BD improved the pour point by $12.5\;^{\circ}C$.