• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.609-617
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• 2000

This study is aimed at investigating an effect of HCl gas on selective reduction of NOx over a CuHM and $V_2O_5-WO_3/TiO_2$ catalyst. SCR process is the most effective method to remove NOx, but catalyst can be deactivated by the acidic gas such as HCl gas which is also included in flue gas from the incinerator. In dry condition of flue gas, the CuHM catalyst treated by HCl gas has shown higher NO removal activity than the fresh catalyst. The activity of the catalyst can be restored by treating at $500^{\circ}C$. On the contrary. $V_2O_5-WO_3/TiO_2$ catalyst is obviously deactivated by HCl and the deactivation increases in proportion to the concentration of HCl gas. The deactivated catalyst is not restored to it's original activity by heat treatment for regeneration. In wet flue gas stream, the CuHM catalyst has shown lower activity than fresh catalyst and $V_2O_5-WO_3/TiO_2$ catalyst was severely deactivated by HCl treatment. The activity loss of catalysts are mainly due to the decrease of Br$\ddot{o}$nsted acid site on the catalyst surface by $NH_3$ TPD. The change of BET surface area of CuHM catalyst after the reaction isn't observed but $V_2O_5-WO_3/TiO_2$ catalyst is observed. The amount of $Cu^{{+}{+}}$ and $V_2O_5$ is decreased after the reaction. From these results, it is expected that CuHM catalyst should be better than $V_2O_5-WO_3/TiO_2$ catalyst for its application to the incineration of flue gas.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.844-850
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• 2002

The potential nutritive value was studied on leaves of seven fodder trees in Central Sudan during dry season at two distinct periods, the early dry and the late. The chemical composition, mineral concentration, in vitro organic matter digestibility (IVOMD), in situ OM or nitrogen degradability and estimated metabolizable energy showed a wide variation among fodder tree species and between different periods of the dry season. Crude protein (CP) ranged from 285 to 197 g/kg DM at early dry season, with a significant reduction in late dry season. Ziziphus spina-christi and Balanites aegyptiaca showed the least reduction in CP content. The NDF, ADF and lignin were about 200, 160 and 19 g/kg DM, respectively at the early period, and significantly increased at the late period of the dry season, except for lignin of Z. spina-christi. For mineral concentration, all fodder tree leaves were rich in calcium but poor in phosphorus. In situ OM degradability significantly decreased at the late period of dry season, but values remained as high as over 600 g/kg OM. At both periods, Z. spina-christi showed the highest value, while the lowest was recorded in Acacia seyal. The IVOMD showed a similar trend to those of in situ OM degradability, except for A. seyal. The nitrogen degradability was highest in B. aegyptiaca and lowest in Z. spina-christi at both periods. A significant and positive correlation had existed between CP and IVOMD or in situ OM degradability (r=0.68, p<0.05; r=0.77, p<0.05, respectively). Also, a significant but negative correlation was found between condensed tannins and nitrogen degradability (r=-0.87, p<0.01). Results demonstrated that Z. spina-christi potentially has a good nutritive value as dry season feed or supplement, while A. seyal tends to be less promising. A. nubica and B. aegyptiaca may be a useful source for degradable protein, even though it may have a limited supply of energy to animals. A. tortilis, A. mellifera and A. ehrenbergiana may have potential value for a supplementation of energy or protein, if they were harvested in the early dry season or in wet season as preserved feed. It is highly recommended to supplement with an appropriate amount of phosphorus when these fodder trees were used.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.1
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• pp.30-34
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• 2016

In this paper, we report that selective etching on N-polar face by EC (electro-chemical)-etching effect on the reduction of bowing and strain of FS (free-standing)-GaN substrates. We applied the EC-etching to concave and convex type of FS-GaN substrates. After the EC-etching for FS-GaN, nano porous structure was formed on N-polar face of concave and convex type of FS-GaN. Consequently, the bowing in the convex type of FS-GaN substrate was decreased but the bowing in the concave type of FS-GaN substrate was increased. Furthermore, the FWHM (full width at half maximum) of (1 0 2) reflection for the convex type of FS-GaN was significantly decreased from 601 to 259 arcsec. In the case, we confirmed that the EC-etching method was very effective to reduce the bowing in the convex type of FS-GaN and the compressive stress in N-polar face of convex type of FS-GaN was fully released by Raman measurement.

• Polymer(Korea)
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• v.29 no.5
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• pp.440-444
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• 2005

An increase in the surface area of drugs by reducing particle sizes from microns to nanometers has been known as an efficient method to improve the bioavailability of water-insoluble drugs. To prevent drug nanoparticles from aggregation during the processes of drug formulation, a limited number of pharmaceutical inactive ingredients such as hydroxypropyl cellulose has been employed as stabilizers or dispersants. In this study, copolymers of hydrophilic and hydrophobic amino acids were synthesized by the ring opening polymerization of their N-carboxyanhydride monomers and evaluated as novel candidates to stabilize the nanoparticles of a water insoluble drug, naproxen. Naproxen nanoparticles stabilized by synthesized amino acid copolymers were successfully prepared in the size of $200\~500nm$ in 60 min by a wet comminution process. Particle size analysis showed that the effective stabilization performance of copolymers required the hydrophobic moiety content to be higher than $10 mol\%$. However, the molecular weight and morphology of copolymers was not the critical parameters in determining the particle size reduction. Their particle size was found to be stable up to 14 days without significant aggregation.

• Journal of Life Science
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• v.21 no.6
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• pp.819-828
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• 2011

To inspect norovirus contamination of groundwater in south eastern areas of Korea, a systematic survey of groundwater in Busan, Ulsan, and Gyeongsangnam-do was performed for two years from 2009 to 2010. For this purpose, we first optimized the nested reverse transcription-PCR condition by designing two sets of primers for the detection of norovirus genogroups, GI and GII. Of 145 samples, 21 (25.9%) and 15 (23.4%) were norovirus positive in the dry season (April to June) and wet season (July to August), respectively. The detection frequencies of norovirus in Busan, Ulsan, and Gyeongsangnam-do were 15%, 7%, and 32%, respectively, reflecting a geographical difference in their distribution. The GI and GII isolates were 5 and 31, respectively, indicating the prevalence of GII in the tested areas. According to phylogenetic analysis of their nucleotide sequences, all of the GI isolates were identified to genotype GI.5 whilst the GII isolates were divided into two genotypes, GII.3 and GII.4. Neither physical-chemical parameters such as pH, temperature, oxidation-reduction potential, and dissolved oxygen, nor microbial indicators of water quality such as total bacteria, total coliforms, and Escherichia coli were statistically correlated with contamination of norovirus in the groundwater. Interestingly, however, the presence of norovirus was closely correlated with low turbidity (<0.50 NTU). The present study suggests that periodical monitoring of norovirus in groundwater is necessary to prevent epidemic waterborne diseases and to secure better sanitary conditions for public health.

• The Journal of Natural Sciences
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• v.8 no.1
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• pp.61-69
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• 1995

It is hard to synthesize pure $BaTiO_3$ from $BaCO_3$ and $TiO_2$ in solid reaction for the activity of BaO and secondary phase. For this reason, the wet chemical techniques have been studied. Starting material which was used in these methods were expensive and the properties of powder which was synthesized in same defined. So, some process have been studying again to improve soild reaction method. This study which was one of those was to defin the forming mechanism of $Ba_2TiO_4$ and to control some condition of $Ba_2TiO_4$. The synthesis temperature of $BaTiO_3$ in solid reaction was near $1120^{\circ}C$. The quantity and forming temperature of $Ba_2TiO_4$ could be controlled by atmosphere heat treatment. $Ba_2TiO_4$ was related to expansion in Ba-rich region of $BaTiO_3$. $BaTiO_2O_5$ and $BaTiO_3O_7$ was reason to expand in Ti-rich region. The dielectrics of $CeAIO_3$ which was synthesized and sintered in reduction atmosphere and $BaTiO_3$ system were affected by $CeO_2$ which was formed for the decomposition of $CeAIO_3$ heat treatment in air.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.977-983
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• 2002

This study was performed to establish the precise and rapid method to distinguish croakers through the pigment analysis of colored imported white croakers for adultration. We surveyed the coloring behaviors, extraction test by water and organic solvent and using pigments such as targeting, curcumine, and azo dye products. The pigment of yellow croaker is not stained on wet cloth or tissue which is rubbed on epidermis of yellow croaker and was not eluted in water extraction test, while adulterated pigments were easily extracted by water and acetone, but edible diluted yellow, Yellow No. 4 and Yellow No. 5 were not extracted. Reactive pigment was detected easily by extraction with water and dispersed pigment was also detected by extraction test. As a result of discoloring characteristics of carotene having similar structure to yellow croaker and azo dye by oxidation and reduction, azo dyes were not discolored by oxidation with sodium percarbonate or peracetic acid but that were discolored by oxidation with Fenton reagent after 1hr and by hypochlorite promptly. On the other hand, carotenes were not discolored by sodium precarbonate and Fenton reagent but discolored by sodium hypochlorite after 2 hr and by peracetic acid promptly. Azo dyes were discolored by reduction with sodium hydrosulfite and sodium carbonate but carotenes were not discolored by these reagents. This discoloring test was applicable to detect adulterated pigments and other marine product.

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.1-7
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• 2002

This study was performed to investigate the possibility of water purification by a wild train of Oenanthe javanica DC. Three commercially available dishwashing detergents and a standard surfactant, linear alkylbenzene sulfonate (LAS), were used for this study. The experiment was done in 1.5 ι transluscent aquariums. The plants were distributed into various concentrations of detergents and various kinds of detergent in the separate aquariums. The wet weight of the plants was significantly decreased (p<0.05), and the visual vitality of the plants also decreased in 2 days. The higher the concentration of detergent was, and the more time the plants were exposed to the detergents, the more decrease of growth was observed. The pH value of the culture media decreased in 2 days and in 4 days, then slightly increased in 6 days. However, the pH value of the media did not return to the initial neutral level of pH in 6 days. The pH value of the culture media containing the LAS remarkably increased in 6 days and increased to a neutral pH value in 18 days (p<0.01) as the pH of the other culture media. The chemical oxygen demand (COD) of the culture media gradually increased over the 4 days. A decrease of COD was observed in 6 days, but no tendency was observed between 12 and 18 days. The detergent in the culture media was highly significantly decreased in 2 days (p<0.01) and gradually decreased after this. After 6 days the remaining detergent was 12.4∼23.7% from the various levels of initially added concentration, and 22.4 ∼34.2% from the flour kinds of detergents. These results show that the reduction of detergent was caused by Oenanthe javanica and the effect was significant during the first 6 days when the plants were still growing well. These results indicate that the plant purifies contaminated water for several days and the effect could be variable according to the level of contamination and the environment in which the plant grows.

• Journal of Animal Science and Technology
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• v.49 no.1
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• pp.67-78
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• 2007

This study was carried out to monitor feed-nutritional components, toxic heavy metals (Cd, Pb and As) and pesticide residues through three cultivation stages (1st initial culture stage, 2nd mycelial growth stage, and 3rd fruit body-harvested stage) of king oyster mushroom (Pleurotus eryngii) produced by bottle type cultivation and oyster mushroom (Pleurotus osteratus) produced by vinyl bag type cultivation. For both cultivation types, compared with the initial culture, the weight reduction rate in spent mushroom substrates (SMS) after fruit body harvest was 29% for total wet mass, 21～25% for dry and organic matters and 19 ～22% for neutral detergent fiber. Two thirds to 3/4 of organic matter degraded and utilized by mycelia and fruit bodies was originated from fiber, of which the primary source (50～70%) was hemicellulose. The effect of mycelial growth stage on chemical compositional change in culture was little (P>0.05) for bottle type cultivation of king oyster mushroom but considerable (P<0.05) for vinyl type cultivation of oyster mushroom. Culture nutrients uptake by fruit bodies was very active for the bottle type cultivation. Compared with SMS, harvested fruit bodies (mushrooms) contained higher (P<0.05) crude protein, non-fibrous carbohydrate, and crude ash and lower (P<0.05) neutral detergent fiber. Regardless of stages, no culture samples were contaminated with toxic heavy metals and pesticide residues. In conclusion, the increase of fiber (neutral and acid detergent fibers) and indigestible protein contents and the decrease of true protein content in SMS indicated that the feed-nutritional value of SMS was significantly reduced compared with that of the initial culture and they were safe from toxic heavy metals and pesticide residues.

• The Korean Journal of Mycology
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• v.7 no.1
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• pp.13-73
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• 1979

These studies were conducted to investigate nutrient sources and supplementary materials of synthetic compost media for Agaricus bisporus culture. Investigation were carried out to establish the optimum composition for compost of Agaricus bisporus methods of out-door fermentation and peakheating with rice straw as the main substrate of the media. The incidence and flora of harmful organisms in rice straw compost and their control were also studied. 1. When rice straw was used as the main substrate in synthetic compost as a carbon source. yields were remarkably high. Fermentation was more rapid than that of barley straw or wheat straw, and the total nitrogen content was high in rice straw compost. 2. Since the morphological and physico-chemical nature of Japonica and Indica types of rice straw are greatly dissimilar. there were apparent differences in the process of compost fermentation. Fermentation of Indica type straw proceeded more rapidly with a shortening the compost period, reducing the water supply, and required adding of supplementary materials for producing stable physical conditions. 3. Use of barley straw compost resulted in a smaller crop compared with rice straw. but when a 50%, barley straw and 50% rice straw mixture was used, the yield was almost the same as that using only rice straw. 4. There were extremely high positive correlations between yield of Agaricus bisporus and the total nitrogen, organic nitrogen, amino acids, amides and amino sugar nitrogen content of compost. The mycerial growth and fruit body formation were severely inhibited by ammonium nitrogen. 5. When rice straw was used as the main substrate for compost media, urea was the most suitable source of nitrogen. Poor results were obtained with calcium cyanamide and ammonium sulfate. When urea was applied three separate times, nitrogen loss during composting was decreased and the total nitrogen content of compost was increased. 6. The supplementation of organic nutrient activated compost fermentation and increased yield of Agaricus bisporus. The best sources of organic nutrients were: perilla meal, sesame meal, wheat bran and poultry manure, etc. 7. Soybean meal, tobacco powder and glutamic acid fermentation by-products which were industrial wastes, could be substituted for perilla meal, sesame meal and wheat bran as organic nutrient sources for compost media. B. When gypsum and zeolite were added to rice straw. physical deterioration of compost due to excess moisture and caramelization was observed. The Indica type of straw was more remarkable in increase of yield of Agricus bisporus by addition of supplementing materials than Japonica straw. 9. For preparing rice straw compost, the best mixture was prepared by 10% poultry manure, 5% perilla meal, 1. 2 to 1. 5% urea and 1% gypsum. At spring cropping, it was good to add rice bran to accelerate heat generation of the compost heap. 10. There was significantly high positive correlation (r=0.97) between accumulated temperature and the decomposition degree of compost during outdoor composting. The yield was highest at accumulated temperatures between 900 and $1,000^{\circ}C$. 11. Prolonging the composting period brought about an increase in decomposition degree and total nitrogen content, but a decrease in ammonium nitrogen. In the spring the suitable period of composting was 20 to 25 days. and about 15 days in autumn. For those periods, the degree of decomposition was 19 to 24%. 12. Compactness of wet compost at filling caused an increase in the residual ammonium nitrogen. methane and organic acid during peak heating. There was negative correlation between methane content and yield (r=0.76)and the same was true between volatile organic acid and yield (r=0.73). 13. In compost with a moisture content range between 69 to 80% at filling. the higher the moisture content, the lower the yield (r=0.78). This result was attributed to a reduction in the porosity of compost at filling the beds. The optimum porosity for good fermentation was between 41 and 53%. 14. Peak heating of the compost was essential for the prevention of harmful microorganisms and insect pests. and for the removal of excess ammonia. It was necessary to continue fer mentatiion for four days after peak heating. 15. Ten species of fungi which are harmful or competitive to Agaricus bisporus were identified from the rice compost, including Diehliomyces microsporus, Trichoderma sp. and Stysanus stemoites. The frequency of occurrance was notably high with serious damage to Agaricus bisporus. 16. Diehliomyces microsporus could be controlled by temperature adjustment of the growing room and by fumigating the compost and the house with Basamid and Vapam. Trichoderma was prevented by the use of Bavistin and Benomyl. 17. Four species of nematodes and five species of mites occured in compost during out-door composting. These orgnanisms could be controlled through peakheating compost for 6 hours at $60^{\circ}C$.