• Korean Journal of Microbiology
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• v.34 no.3
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• pp.82-86
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• 1998

An alkaline proteinase secreted from Yarrowia lipolytica 504D was purified by salting-out and column chromatography. The molecular weight of the purified enzyme was about 32,000 Da estimated by SDS-PAGE. The optimal condition for the activity of the enzyme was at pH 9.5 and $42^{\circ}C$ The enzyme was stable up to $45^{\circ}C$ and at the range of pH 4-10. Because the enzyme was inhibited by PMSF as well as EDTA, EGTA, and phenan-throlin, it is uncertain whether the enzyme is serine proteinase or metalloproteinase. However, almost all metal salts tested did not increase the enzyme activity, and Ca salt restored the activity of the enzyme inactivated by EDTA. Therefore, the purified enzyme seems to be an serine proteinase (E.C. 3.4.21.14).

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.719-731
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• 2003

In order to maintain and manage ambient air quality, it is necessary to identify sources and to apportion its sources for ambient particulate matters. The receptor methods were one of the statistical methods to achieve reasonable air pollution strategies. Also, receptor methods, a field of chemometrics, is based on manifold applied statistics and is a statistical methodology that analyzes the physicochemical properties of gaseous and particulate pollutant on various atmospheric receptors, identifies the sources of air pollutants, and quantifies the apportionment of the sources to the receptors. The objective of this study was 1) after obtaining results from the PMF modeling, the existing sources of air at the study area were qualitatively identified and the contributions of each source were quantitatively estimated as well. 2) finally efficient air pollution management and control strategies of each source were suggested. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols, the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided quantitative source contributions (scaled G matrix) and source profiles (scaled F matrix). The results of the PMF modeling showed that the sources were apportioned by secondary aerosol related source 28.8 ％, soil related source 16.8％, waste incineration source 11.5%, field burning source 11.0%, fossil fuel combustion source 10%, industry related source 8.3％, motor vehicle source 7.9%, oil/coal combustion source 4.4％, non-ferrous metal source 0.3％. and aged sea- salt source 0.2％, respectively.

• Journal of Ocean Engineering and Technology
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• v.24 no.5
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• pp.60-66
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• 2010

Zinc has a number of characteristics that make it well suited for use as a coating to protecting iron and steel products from corrosion. Its excellent corrosion resistance in most environments accounts for its successful use as a protective coating on a variety of products and in many exposure conditions. The excellent field performance of zinc coatings results from their ability to form dense, adherent films that corrode at a rate that ranges from 1% to 10% of the corrosion rate of ferrous materials, depending on the environment. Recently, EU RoHS and EU ELV prohibited the use of materials that adversely affect the environment, such as Pb, Hg, Cd, and $Cr^{+6}$. In this study, environmentally-friendly, Cr-free solutions (epoxy solution, acrylic solution, and urethane solution S-700) and organic/inorganic solution with Si; LRO-317) were used to evaluate the corrosion resistance of zinc-coated steel subjected to a saltwater spray for 72 hours. The coating of urethane solution (S-700) was best among the three kinds of solution with heat treatment during five minutes at $190^{\circ}F$. Test specimens with S-700 and LRO-317 coating were heat treated in a drying oven at 170, 180, 190, 200, and $210^{\circ}C$ for five minutes. The results show that the optimum corrosion resistance was $190^{\circ}C$ in EGI and $170^{\circ}C$ in HDGI, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.112-120
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• 2006

For the conversion of food waste into a good recycling material such as animal feed without antibiotics, thirteen lactic acid bacteria, which can be used as good probiotics for animal feed, were isolated from the intestine and feces in pigs. All isolates showed strong tolerance to high salt (4% of NaCl), acid(pH4.0), and bile juice (0.8% of oxgall). The growth rate was best at $37^{\circ}C$ in all strains. Among the isolates, Lactobacillus plantarum CJY-22, L. brevis CJY-42, L. arizonensis CJY-3, and Pediococcus sp. CJY-41 showed higher and broader spectrum of antimicrobial activities against six different pathogens such as Salmonella, typhimurium. L. plantarum CJY-22 has also grown well at $25^{\circ}C$, making this strain as an appropriate candidate for the fermentation of food waste at room temperature, thus conducting the fermentation process cost-effectively.

• International Journal of Industrial Entomology and Biomaterials
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• v.16 no.2
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• pp.67-74
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• 2008

A line x tester analysis was carried out in mulberry (Morns spp.) under different salinity levels to determine the changes in the genetic interaction of various morpho-biochemical characters. Five mulberry genotypes, 3 females and 2 males, differing in salt tolerance were selected for the study. Clones of these parents along with clones of the F1 hybrids were planted in earthen pots and subjected to different levels of salinity (0.0%, 0.25%, 0.50%, 0.75% and 1.00% NaCl). Data on morphological and biochemical characters were subjected to line x tester analysis. The result revealed significant variation among the parents studied. The prominence of non-additive gene effect under control condition suggests the need for well chalked out breeding program to exploit the non-fixable variance of components for improvement of plant height, leaf size and leaf yield, chlorophyll and photosynthesis in mulberry. However, under salinity stress a shift from non-additive gene effect to additive gene effect for the above said character further suggests the need for a change in breeding strategy. The general combining ability (GCA) analysis has identified English black as the best combiner among the parents and the specific combining ability analysis (SCA) found crosses of English black X C776 and Rotndiloba x Mandalaya were good for Plant height and leaf size and English black X C776 and Rotundiloba x C776 were good for biochemical proline and chlorophyll. From the performance of parents and their crosses under different salinity levels and also under normal cultural conditions it is concluded that in mulberry different approaches are required to develop varieties for the irrigated and saline conditions.

• Journal of Microbiology and Biotechnology
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• v.26 no.5
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• pp.854-866
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• 2016

The production cost of biodiesel from microalgae is still not competitive, compared with that of petroleum fuels. The genetic improvement of microalgal strains to increase triacylglycerol (TAG) accumulation is one way to reduce production costs. One of the most promising approaches is the isolation of starch-deficient mutants, which have been reported to successfully increase TAG yields. To date, such a stable mutant is not available in an oleaginous marine microalga, despite several advantages of using marine species for biodiesel production. Algae in the genus Dunaliella are known to tolerate high salt concentration and other environmental stresses. In addition, the cultivation processes for large-scale outdoor commercialization have been well established for this genus. In this study, Dunaliella tertiolecta was used to screen for starch-deficient mutants, using an iodine vapor-staining method. Four out of 20,016 UV-mutagenized strains showed a substantial reduction of starch content. A significantly higher TAG content, up to 3-fold of the wild-type level, was observed in three of the mutants upon induction by nitrogen depletion. The carotenoid production and growth characteristics of these mutants, under both normal and oxidative stress conditions, were not compromised, suggesting that these processes are not necessarily affected by starch deficiency. The results from this work open up new possibilities for exploring Dunaliella for biodiesel production.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.13-23
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• 2016

This study was conducted to investigate the growth characteristics of warm-season turfgrasses and to find out suitable turfgrass species on Saemangeum reclaimed land. Twenty native zoysiagrass(Zoysia sinica, Z. matrella, Z. japonica, Medium-leaf type zoysiagrass(hybrid zoysiagrass)) and bermudagrass(Cynodon dactylon) collected from Korea were used in this study. Total stolon length and the number of stolon per square meter, relative growth rate of shoot and stolon, and coverage rate were analyzed for 2 year. C. dactylon showed not only the most growth response with high relative growth rate of shoot and stolon, which were 19.9% and 66.3%, but also resulted in higher level of turf visual quality compared to others. Whereas Z. japonica showed the least growth response with low relative growth rate of shoot and stolon, which were 2.4% and 0.7%. Although all warm-season turfgrasses took root and grew up well, there were different growth rates between the interspecies. Z. sinica 'Z2034', Z. matrella 'Z4091', Z. japonica 'Z1064', Medium-leaf type zoysiagrass 'ZN6019' and C. dactylon 'BN7014' were the greatest growth rate of shoot and stolon. These results will be useful for selecting salt tolerant breeding lines and also used to develop a turfgrass cultivar with strong salinity tolerance through continuous monitoring.

• Journal of the Korean Society of Food Culture
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• v.26 no.5
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• pp.455-467
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• 2011

The main purpose of this study was to survey the various kinds of recipes for pheasant found in seventeen Korean cookbooks published from the 1800's to the 1990's. There were 95 pheasant recipes found in the literature which could be classified into three major groups: cooking with moist heat, cooking with dry heat, and other. The three major groups were then broken down into thirteen smaller groups. A detailed look at the frequency of terms in each recipe shows that Gui Sanjeok (grilled Korean shish kebabs) appears 24 times, Guk Tang and Jeongol (soup and stew) 23 times, Kimchi (fermented cabbage) 11 times, Po (jerky) 9 times, Jorim (boiled in soy sauce) 7 times, Jjim (steamed) 6 times, Bokeum (stir-fried) 5 times, Twigim (deep-fried) 3 times, Buchim (fried) 2 times, Jigae jijim (stewed) 2 times, and Jang (paste), Myeon (noodles), Gooum (boiled) and Yeot (Korean hard taffy) 1 time each. The main ingredient is always the pheasant. We investigated the use of the whole pheasant cooked, how to slice and tenderize pheasant meat, use the meat only, or use only certain parts. Depending on the characteristics of cooking recipes, pheasants with thin, soft bones and organs were investigated for cooking. Substituted materials were used for a few of the vegetables, meat, and seafood in the recipes, and seem to go well together. Garnishes used included pine nut powder and fried eggs. Seasoned salt, soy sauce, pepper, sesame, sesame oil, chopped onion, garlic, and ginger were also reported to have been used.

• Membrane and Water Treatment
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• v.6 no.2
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• pp.127-139
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• 2015

Rejection of ionic solutes by reverse osmosis (RO) and nanofiltration (NF) membranes is controlled mainly by electrochemical interaction as well as pore size, but it is very difficult to directly evaluate such electrochemical interaction. In this work, we used an inverse HPLC method to investigate the interaction between ionic solutes and poly (m- phenylenediaminetrimesoyl) (PPT), a polymer similar to the skin layer of polyamide RO and NF membranes. Silica gel particles coated with PPT were used as the stationary phase, and aqueous solutions of the ionic solutes were used as the mobile phase. Chromatographs obtained for the ionic solutes showed features typical of exclusion chromatographs: the ionic solutes were eluted faster than water (mobile phase), and the exclusion intensity of the ionic solute decreased with increasing solute concentration, asymptotically approaching a minimum value. The charge density of PPT was estimated to be ca. 0.007 mol/L. On the basis of minimum exclusion intensity, the exclusion distances between a salt and neutralized PPT was examined, and the following average values were obtained: 0.49 nm for 1:1 salts, 0.57 nm for 2:1 salts, 0.60 nm for 1:2 salts, and 0.66 nm for 2:2 salts. However, $NaAsO_2$ and $H_3BO_3$, which are dissolved at neutral pH in their undissociated forms, were not excluded.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.3
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• pp.291-299
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• 2018

Under a pyro-processing concept, an electrolytic reduction process has been developed to reduce uranium oxide in molten salt by electrochemical means as a part of spent fuel treatment process development. Accordingly, a model based on electrochemical theory is required to design a reactor for the electrolytic reduction process. In this study, a 1D model based on the phase-field theory, which explains phase separation behaviors was developed to simulate electrolytic reduction of uranium oxide. By adopting parameters for diffusion of oxygen elements in a pellet and electrochemical reaction rate at the surface of the pellet, the model described the behavior of inward reduction well and revealed that the current depends on the internal diffusion of the oxygen element. The model for the electrolytic reduction is expected to be used to determine the optimum conditions for large scale reactor design. It is also expected that the model will be applied to simulate the integration of pyro-processing.