• Korean Journal of Food Science and Technology
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• v.13 no.3
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• pp.194-201
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• 1981

In order to determine the residue levels of organochlorine insecticides in various meats consumed by Korean population, 80 samples of beef, pork and chicken were collected throughout the country and analyzed for their fat contents and pesticide residue levels. Organochlorine insecticides detected in the meat samples were ${\alpha}-BHC,\;{\beta}-BHC,\;heptachlorepoxide\;and\;DDE$. The average residue levels of the four pesticides on fat basis were 0.466 ppm in domestic beef, 0.145 ppm in imported beef, 0.264 ppm in pork and 0.106 ppm in chicken, in decreasing order of ${\alpha}-BHC>DDE>heptachlorepoxide>{\beta}-BHC$. Daily intake per person of the residues from meat by Korean population was estimated to be $1.0{\mu}g$ of total BHC, $0.1{\mu}g$ of heptachlorepoxide and $0.3{\mu}g$ of DDE. This level was far below the acceptable daily intake of organochlorine insecticides $(18\;{\mu}g/㎏\;body\;weight)$ as recommended by FAO/WHO.

• Bulletin of the Korean Chemical Society
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• v.24 no.12
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• pp.1742-1750
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• 2003

In order to characterize the hydrophobic parameters of N-acetyl amino acid amides in 1-octanol/water, a theoretical calculation was carried out using a solvation free energy density model. The hydrophobicity parameters of the molecules are obtained with the consideration of the solvation free energy over the solvent volume surrounding the solute, using a grid model. Our method can account for the solvent accessible surface area of the molecules according to conformational variations. Through a comparison of the hydrophobicity of our calculation and that of other experimental/theoretical works, the solvation free energy density model is proven to be a useful tool for the evaluation of the hydrophobicity of amino acids and peptides. In order to evaluate the solvation free energy density model as a method of calculating the activity of drugs using the hydrophobicity of its building blocks, the contracture of Bradykinin potentiating pentapeptide was also predicted from the hydrophobicity of each residue. The solvation free energy density model can be used to employ descriptors for the prediction of peptide activities in drug discovery, as well as to calculate the hydrophobicity of amino acids.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.167-170
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• 2013

Lignin can be a valuable natural chemical resource. Structurally, lignin is a three-dimensional polymer made up of condensed C-C bonds and some ether linkages, most of which are not readily degraded. In this study, lignin carbonization under various electron beam pretreatment conditions was characterized through a thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Raman spectroscopy. Lignin stabilization was controlled by various doses of electron beam irradiation corresponding to 50, 100, 200, 500 and 1,000 kGy; the carbonization process was performed under a nitrogen gas atmosphere at $1000^{\circ}C$ for 1 h. The TGA results showed that a 1,000 kGy lignin dose increased the residue weight from 39.96% to 45.23%, compared to non-irradiated lignin. This observation is in agreement with the XRD and Raman spectroscopy results, in which the two theta degrees and the degree of crystallization were improved by increasing the electron beam irradiation.

• Current Photovoltaic Research
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• v.2 no.1
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• pp.36-39
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• 2014

Formation mechanism of residual carbon layer, frequently observed in the $CuInSe_2$ (CIS) thin film prepared by direct solution coating routes, was investigated in order to find a way to eliminate it. As a model system, a methanol solution with dissolved Cu and In salts, whose viscosity was adjusted by adding ethylcellulose (EC), was chosen. It was found that a double layer, a top metal ion-derived film and bottom EC-derived layer, formed during an air drying step presumably due to different solubility between metal salts and EC in methanol. Consequently, the top metal ion-derived film acts as a barrier layer inhibiting further thermal decomposition of underlying EC, resulting a formation of bottom carbon residue layer.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.526-532
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• 2016

In this study, we synthesized a mediator immobilized biocatalyst([FCA/GOx]/PEI/CNT) by surface modification using ferrocene carboxylic acid(FCA), and evaluated its performance as anode catalyst for biofuel cell. Through the application of FCA on glucose oxidase (GOx), the free amine groups on the lysine residue of GOx surface reacted with carboxylic acid of FCA and make amide bond between GOx and FCA. As the result of that, the electron transfer of catalyst was increased up to 1.91 times($0.468mA{\cdot}cm^{-2}$) than the catalyst without surface modification (GOx/PEI/CNT), and high maxium power density of $1.79mA{\cdot}cm^{-2}$ was gained.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.3
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• pp.420-424
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• 1987

The model reduction methods of the linear time invariant continuous systems are proposed. The energy dispersion method is used to obtain the model denominator. And the model numerator is found by the modified residue method or the time moment matching method. The methods suggested are compared with the method suggested by Lucas and give good results.

• Analytical Science and Technology
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• v.7 no.2
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• pp.193-199
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• 1994

We have synthesized K-CFICs by the modified two-bulb method. These synthesized compound were analysed with X-ray diffractometer and UV/VIS spectrophotometer. According to X-ray diffraction analysis, the intercalation of potassium between the carbon layers of carbon fiber was better then other intercalants. From obtained data for this deintercalation process, we can see that a number of potassiums were presented as a residue between the carbon layers and this residue compounds had a stability for a long term. Therefore, it is appear that these compounds have a capability as new useful material. From UV/VIS spectrometry data, we can suppose that spectrum of K-CFICs synthesized at $250^{\circ}C$ had only a $R_{min}$, and spectra of any other compounds were not appeared charecteristic peaks because potassium ions were little affect the energy levels of original carbon fiber.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.114.2-114.2
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• 2011

Furfural is a versatile derivative. It can be utilized for a building-block of furfuryl alcohol production and a component of fuels or liquid alkanes. But in bio-process, furfural is a critical compound because it inhibits cell growth and metabolism. Furfural could be converted from xylose and usually produced from biomass in which hemicellulose is abundant. In this study, furfural production from miscanthus was performed and utilization of miscanthus residue was consequently conducted. At first, hydrolysis for investigation of miscanthus composition and furfural production was performed using sulfuric acid. Previously, we optimized dilute acid pretreatment condition for miscanthus pretreatment and the condition was found to be about 15 min of reaction time, 1.5% of acid concentration and about $140^{\circ}C$ of temperature and 60% (about 7 g/L) of xylose was solubilized from miscanthus. Using the xylose, furfural production was conducted as second step. Approximately $160{\sim}200^{\circ}C$ of temperature was accompanied with the hydrolysis for pyrolysis of biomass. When the investigated condition; $180^{\circ}C$ of temperature, 20 min of reaction time and 2% of acid concentration was operated for furfural production, furfural productivity was reached to be 77% of theoretical maximum. After reaction, residue of miscanthus was utilized as feedstock of ethanol fermentation. Residue was well washed using water and saccharified using hydrolysis enzymes. Hydrolysate (glucose) from saccharification was utilized for the carbon source of Saccharomyces cervisiae K35.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.391-399
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• 2023

Recently, low-temperature pyrolysis technology has been studied as a recycling method for waste plastic. Low-temperature pyrolysis technology for waste plastic produces pyrolysis oil that can be used as an energy resource, but solid residue remains. Waste plastic pyrolysis residues are mostly landfilled due to their limited use. In this study, it is investigated that mixed waste plastic pyrolysis residues could be recycled into activated carbon. It was confirmed that the fixed carbon content of the residue was 33.69 % from proximate Analysis. Chemical activation was used to manufacture activated carbon. KOH was used as an activator. To investigate the effect of the mixing ratio of KOH and residue, samples were mixed at ratios of 0.5, 1.0, and 2.0. The mixed sample was chemically activated at an activation temperature of 800 ℃ for 1 hour. As a result of analyzing the characteristics of activated carbon through BET, it was confirmed that the specific surface area increased as the mixing ratio of KOH increased.

• Journal of Integrative Natural Science
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• v.2 no.1
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• pp.1-12
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• 2009

This miniaccount presents the selective examples of our recent discoveries in the photopolymerization of vinyl monomers using the organic initiators such as hydrosilanes, poly(hydroarylsilane)s, benzoin silyl ethers, and thianthrene cation radical. In the photopolymerization of vinyl monomers with silanes polysilanes, while the polymerization yields and polymer molecular weights of the poly(MMA)s containing the silyl moieties decreased, the TGA residue yields and intensities of SiH stretching IR bands increased as the mole ratio of the silanes over MMA increased. The hydroarylsilane and poly(hydroarylsilane) seemed to influence strongly on the photopolymerizaiton of olefinic monomers as both chain initiation and chain transfer agents. For the photohomopolymerization and photocopolymerization of MA and AA, the similar trends were observed. Benzoin silyl ethers and thianthrene cation radical also exhibit the photoinitiating ability in the photopolymerization of MMA.