• Korean Journal of Ecology and Environment
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• v.38 no.4 s.114
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• pp.494-502
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• 2005

Antialgal bacteria and ciliates were tested alone and in combination for their abilities to decrease the densities of the warm-weather cyanobacterium, Microcystis aeruginosa, and the cold-weather centric diatom, Stephanodiscus hantzschii. Our results indicate that the density of M. aeruginosa was effectively suppressed by the bacterium, Streptomyces neyagawensis, and the heterotrich ciliate, Stentor roeselii. However, co-treatment with both bio-agents stimulated the algal density rather than decreasing it, suggesting that S. neyagawensis and S. roeselii may have an antagonistic relationship. Additional experiments revealed that the density of S. hantzschii was effectively suppressed by the bacterium, Pseudomonas putida, and by the above mentioned strain of S. roeselii. Co-treatment with both bio-agents had a higher antialgal activity than treatment with each alone, indicating that the bio-agents may act synergistically. These results suggest that the anti-alge efficacy of co-treatment with multiple biological control agents is likely to differ depending on the bio-agents and target organisms.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.268-273
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• 2006

This study analyzed the technological change of Korean sawmill industry affected by change of factor price. An aggregate cost function has been estimated to analyze the technological change in Korean sawmill industry between 1970 and 2003 to the technical bias and scale effect. There was substitution among labour, capital, and material, especially in more elastic relation between labour and capital. In addition, domestic sawmill industry was progressed into structure which is biased to labour saving, and capital and material using because of increase of labour price. Since Korean sawmill industry's technology still exhibits an increasing returns to the scale, the large amount of investment has contributed to productivity growth, and the future productivity growth continually depend on the scale effect for some time.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.3
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• pp.75-86
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• 2003

In the near future, the capacity of conventional anaerobic digester is thought to be insufficient because of the increase of the total solids from expansion of intercepting sewer, sewage quantity and direct input of night soil from near apartment districts. The objectives of this study was to investigate the improvement of digestion efficiency using microbial agent(Bio-dh). The system was a pilot-scale, two-staged, anaerobic sludge digestion system. The first-stage digester was heated and mixed. The agitation velocity of the first-stage digester was 120rpm. The second-stage digester was neither heated nor mixed. The Digestion temperature was kept at $35{\pm}1^{\circ}C$ The detention time of digester was 19 days. The dosage of sewage sludge and microbial agent were $0.65m^3/day$ and $0.5{\ell}/day$, respectively. The experiments was run for 25days. Three times a week, $COD_{Mn}$ and SS of effluent, TS, VS, and biogas production rate were measured. Temperature, pH, and alkalinity were measured daily. The results were as follows ; Without microbial agent, digestion efficiencies ranged 46.0%~50.9%(mean=48.6%), with microbial agent(Bio-dh), digestion efficiencies ranged 52.8%~57.3%(mean=54.2%). Consequently, microbial agent(Bio-dh) increased the sludge digestion efficiency about 12%. Also, Without microbial agent, the mean concentration of $COD_{Mn}$ and SS of second-stage digester effluent were 1,639mg/L, 4,888mg/L respectively. With microbial agent, the mean concentration of $COD_{Mn}$ and SS of second-stage digester effluent were 859mg/L, 2,405mg/L respectively. Consequently, microbial agent(Bio-dh) increased the removal efficiency of $COD_{Mn}$ and SS about 47.6% and 50.8%, respectively.

• The Korea Swine Journal
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• v.18 no.7 s.203
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• pp.80-81
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• 1996

포유자돈에서 콕시디윰을 예방하기 위해서는 3일령 포유자돈에게 항 콕시디윰 제재를 구강으로 투약하면 된다. 특히 주의해야 할 사항은 가끔 포유자돈에서 모유를 먹지 않은 공복의 포유자돈에게 항 콕시디움 치료제재를 구강으로 투약하면 구토를 일으킬 수 있다. 또한 항 콕시디윰 제제도 일반 항생제와 같이 오랜 기간 지속적으로 사용하면 내성이 유발되기 때문에 동일한 약을 3개월 이상 사용하지 않도록 한다.

• 해운
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• no.10 s.32
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• pp.21-26
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• 2006

북한의 핵실험으로 국제사회가 술렁이고 있다. 특히, 유엔 안전보장이사회는 대북제재 결의안을 통과시키는 등 경제적인 제재를 포함한 다각적인 규제방안을 모색하고 있다. 북한의 핵실험은 이제 국제적인 이슈로 부각되었으며, 우리 경제에도 영향을 미칠 것으로 전망되고 있다. 다음은 대외경제정책연구원이 발표한 '북한핵실험이 한국경제에 미치는 영향'을 정리한 것이다

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.484-490
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• 2013

This study was conducted to develop a simulation model for estimating the amount of such products as round wood, dimension lumber and the residual wood biomass produced by processing the individual trees of Larix kaempferi. In the model, the stem volume is assessed using the taper equations of the species to estimate the stem forms. Then, the model simulates the conversion processes of logs to round wood or lumber and assesses the maximum amount of the wood products by the lumber dimensions or round wood size. Also the model provides information on the amount of residuals for kerf and slabs produced on the conversion processes for sawn timber or round wood. According to the results of an application of the model to a L. kaempferi process, the trees greater than 12 cm of DBH can be converted to logs for lumber or round wood production. For the trees, of which DBH is available for log conversion, the maximum amount of final products by dimensions were analyzed. In this analysis, production of the bigger dimension lumber was assumed to be preferred to that of the smaller or round wood. This model can be used for assesment of forest economic value through estimation of merchantable volume for the trees, and assessment of mill residues which has the potential to provide significant amount of feedstock for bioenergy production as well.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.45-51
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• 2005

As a silicate source to rice, a coal ash (50%) was mixed with a phosphogypsum (hereafter, gypsum, 50%). Field experiments were carried out to evaluate rice (Oryza sativa) productivity in silt loam (SiL) to which 0, 20, 40 and $60Mg\;ha^{-1}$ of the mixture were added. The mixture increased rice yield and showed the highest yields following the addition of $30Mg\;ha^{-1}$. The mixture did not result in an excessive uptake of heavy metals by the rice grain. The mixture improved available silicate and phosphate and exchangeable calcium contents in soil. The available boron content in soil increased with the mixture application levels up to $1.42mg\;kg^{-1}$ following the application of $60Mg\;ha^{-1}$, but boron toxicity in rice was not found. It is concluded that the coal ash and gypsum mixture could be a good alternative to inorganic soil amendments to restore the soil nutrient balance in paddy soil.

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.115-121
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• 2001

Biological Treatment of Wastewater Containing Chlorinated Phenols by a Mixed Culture. Lee, Wan-Seok1, Sang-Wook Jung, Chan-Sun Park, Byung-Dae Yoon, Jang-Eok Kim\ and Hee-Mock Oh*. Environmental Bioresources Laboratory, Korea Research Institute of Biosicence and Biotechnology, Taejon, Korea, 1 Department of Agricultural Chemistry, Kyungpool< National University, Taegu, Korea - The biodegradation of chlorinated phenols in an artificial wastewater was investigated using a mixed culture. The mixed culture was composed of 8 microorganisms isolated from the soil contaminated with various chlorinated phenols. Pseudomonas sp. BM as a main constituent of a mixed culture was Gram-negative, catalase- and oxidase-positive, and rod-shaped, and did not grow at 41°C. It degraded 99% of initial 500 mg!1 of pentachlorophenol (PCP) in the minimal salts medium as a sole source of carbon and energy within 3 days. The degradation efficiency of Pseu.domon.as sp. BM was not affected by the other organic carbon and nitrogen compounds. Pseudomonas sp. BM was able to grow in a broad range of pH 5 - 8, and degrade 2,000 mg/1 PCP. In the experiment with an artificial wastewater containing chlorinated phenols, the degradation efficiency of the mixed culture was the range of 73% (2,4-dichlorophenol) -96% (2-chlorophenol) during an incubation of 7 days. In a continuous culture experiment, the degradation efficiency of mixed culture plus activated sludge was about 2 times higher than that of the control containing only activated sludge. These results indicate that it is possible to apply the mixed culture to other wastewaters containing chlorinated phenols. Key words: Biodegradation, chlorinated phenols, pentachlorophenol, Pseudomonas sp. BM

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.8-14
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• 2002

Cotinine, one of nicotine metabolites, has been blown to reduce 4-(methylnitro samino)-1-(3-pyridyl)-1-butanone(NNK)- induced $O^{6}$MeG DNA adducts significantly in A/J mice when administered together with NNK. In order to examine the effects of phyto-extract mixture on the conversion of cotinine from nicotine, cellular and clinical experiments were carried out. When the phyto-extract mixture was added to culture media, human liver cells (FLCFR5) produced cotinine from nicotine 2~3 times compared to the control. The phyto-extract mixture which was microinjected into Xenopus oocyte along with nicotine showed the almost similar production of cotinine compared with the results of hepatic cell culture. In clinical test employing 17 to 20 healthy men, concentrations of urinary cotinine derived from smoking after taking photo-extract mixture increased up to 2 times compared to the control group. These results indicatethat the phyto-extract mixture can increase the metabolic efficiency of nicotine to cotinine, leading to the reduced formation of $O^{6}$MeG DNA adducts.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.4
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• pp.405-421
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• 2019

International aid to North Korea remains far below the humanitarian needs of vulnerable people. This paper examines the trajectory of international humanitarian assistance to North Korea over the last two decades with the focus on its decline in the context of the country's nuclear standoff and corresponding stringent sanctions. In so doing, the paper addresses major problems associated with North Korea's reception of foreign aid and operational constraints placed on humanitarian activities in the country. It shows that humanitarian assistance to North Korea has been largely shaped by geopolitical dynamics. A survey of UN reports and statistics also suggests a shifting trend in recent international aid to North Korea. The decline of aid and multiple operational obstacles faced by humanitarian organizations, for instance, have led to a fall in agricultural support and a proportional rise in health and related services. While UN Security Council resolutions include an exemption provision, humanitarian assistance to North Korea has been constrained by stringent sanctions, which have led to adverse consequences for the civilian population. In this regard, the paper suggests some policy directions for international aid to North Korea amidst negotiations over denuclearization, while stressing an urgent need to address the negative impact of sanctions on vulnerable groups in the country.