• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.419-424
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• 1989

To obtain relative effectiveness in fire resistance among fire retardant chemicals, oxygen indices were determined for 3.5 mm thick, three-ply, meranti plywoods, treated with 5 commercial chemicals and water and then press-dried, through Up and Down method following oxygen index test of ASTM D 2863-77. The oxygen indices obtained were 28.4 for ammonium sulfate, 26.9 for monoammonium phosphate, 43.4 for diammonium phosphate, 30.1 for borax-boric acid, 32.4 for minalith, and 25.5 for water. Therefore, diammonium phosphate was found to rank first in fire-retardant effectiveness, followed by minalith, borax-boric acid, ammonium sulfate, and monoammonium phosphate in turn, judging from the fact that highly flammable materials are likely to have a low oxygen index.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.507-512
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• 1996

저준위 방사성 폐액의 전처리공정으로써 한외여과막의 적용성을 평가하기 위해서 폐액내에 있는 오일과 계면활성제의 상호작용을 규명하고 오일에멀젼 용액의 fouling정도를 조사하였다. 막의 fouling을 감소시키는 한 방법으로 계면활성제에 의해 막의 표면을 개질하므로서 막투과 flux는 크게 증가되는 효과를 얻었다. 친수성막과 소수성막에 대하여 몇가지 계면활성제로 처리한 후 성능을 비교한 결과 소수성인 폴리솔푼막에 대한 SDS의 표면개질이 가장 유리하였다. 표면처리 막의 적용성을 평가한 결과 미량의 계면활성제나 염이 포함된 오일에멀젼 용액에 대해서는 매우 우수한 투과 성능을 얻을 수 있으나 CMC 이상의 계면활성제가 포함된 오일용액에 대해서는 처리가 불가능하였다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.2
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• pp.3-15
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• 2003

Recently more than 450 incidents of oil spill a year have occurred in nearshore of Korea, which caused unmeasurelable losses in fisheries and severe damage in marine ecosystem. Two approaches remain paramount in any response to marine oil spill : the enhancement of natural dispersion of the oil by using dispersants, and mechanical recovery using booms and skimmers. A technique currently receiving fresh attention is the enhancement of the natural bioremediation of oil through the application of micro-organisms and/or nutrient. Oil, like many natural substances, will biodegrade over a period of time into simple compounds such as carbon dioxide, water and biomass. Bioremediation is the term used to describe a range of processes which can be used to accelerate natural biodegradation. More specifically biostimulation is the application of nutrients, and bioaugremetation or seeding is the addition of microbes specially selected to degrade oil. Bioremediation is an economically attractive method for the clean-up of oil-contaminated area. Bioremediation has been demonstrated to be an effective oil spill countermeasure for use in cobble, sand beach, salt marsh, and mud flat environment.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.258-263
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• 2007

Ammonia water was investigated as a new absorbent of the chemical absorption process for the removal of $CO_2$ in flue gas. The suitable range of ammonia water concentration and $CO_2$ loading ($mol\;CO_2/mol\;NH_3$) were decided in the point of view of $CO_2$ absorption capacity and $NH_4HCO_3$ precipitation. The absorption capacity of $CO_2$ and the precipitation of $NH_4HCO_3$ in liquid phase were calculated by the Pitzer model for electrolyte solution. The $CO_2$ absorption capacity of the ammonia water over $5\;molNH_3/kgH_2O$ was higher than that of conventional amine absorbent. The $CO_2$ loadings where precipitation occurred were decided at various absorbent concentrations. Theses values were higher than 0.5 in the concentration range of $5-14\;molNH_3/kgH_2O$ at 293, 313 K. The absorber for the removal of $CO_2$ in flue gas could be operated without $NH_4HCO_3$ precipitation by using high concentration of ammonia water below these $CO_2$ loading values. The optimum temperature of the ammonia water absorbent for removal of $CO_2$ in flue gas was 297-312 K depending on the concentration of ammonia water.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.567-573
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• 2012

This study was carried out to examine the effect of soil amendment treatments [(organic fertilizer: 20 kg $tree^{-1}$; compound fertilizer+wood-char fertilizer: compound fertilizer 4 kg $tree^{-1}$+wood-char 2 kg $tree^{-1}$; lime fertilizer: 3 kg $tree^{-1}$; mixed fertilizer: compound fertilizer 1 kg $tree^{-1}$+organic fertilizer 10 kg $tree^{-1}$+wood-char 1 kg $tree^{-1}$; control (no fertilizer)] on flowering and fruit characteristics in chestnut (Castanea crenata S. et Z.) orchards in Jinju and Sancheong, Gyeongsangnam-do. Diameter of fruiting shoot increased generally after soil amendment treatments compared with the control, while number of leaf, female and male flowers were not affected by the treatments. Nut weight increased after soil amendment treatments in Jinju, but was not affected by the treatments in Sancheong. There was a positive correlation between soil pH (r=0.91) or exchangeable $Ca^{2+}$ (r=0.99) and nut weight in Jinju and a positive correlation (r=0.97) between organic carbon content and soluble solid concentration, while a negative correlation (r=-0.92) between exchangeable $Mg^{2+}$ and soluble solid concentration of nuts in Jinju. However, the nut weight and soluble solid concentration in Sancheong were not correlated with soil properties. The results indicate that the characteristics of flowering and nuts in chestnut orchards depend on soil properties after soil amendment treatments between regions which show better responses on poor sites than on good sites.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.304-311
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• 2021

This Experiment was conducted to determine the effects of light shield materials when melon grown inside a plastic greenhouse in summer season. The average temperatures were 36.6℃, 34.5℃ and 34.0℃ respectively for the control(non-shield), coating agent, and the white net. The light transmittances were 69% and 75%, respectively inside the greenhouse treated with the coating agent and white net immediately after applicants, compared with that inside the control greenhouse. At the 40 and 80 days after treatment, the light transmittances for the coating agent were 92% and 98%, respectively, indicating it was slowly decomposed and removed, but there was no change in the transmittance for the white net. While the leaf number did not differ among the treatments, the plant height was higher in the white net and shading agent than in control. The weight of the leaves, fresh-weight and dry-weight were no different from that of shading, but it became heavier in the later stages. The marketable fruit yield was increased by 6% for white nets and 5% for the coating agent compared to control, there was no statistical significance. Therefore, coating agent is considered as an effective method to lower temperature during high temperature period, but it is preferable to use it in consideration of cultivation period, because the coating agent is gradually removed.

• Journal of fish pathology
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• v.26 no.3
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• pp.275-282
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• 2013

The use of activating treatment agent (formerly acid treatment agent) has been an effective strategy to remove deleterious epibiont organisms such as diatoms and green seaweeds, and it has greatly contributed to increase in Porphyra production. Although many manufacturers supply many kinds of activating treatment agent with different components in these days, no report about their effects on Porphyra culture was found. In this paper, effects of a commercial activating treatment agent were evaluated for practical use in Porphyra culture. No difference was found in dead cell ratios(%) of Porphyra yezoensis thalli between treated and control groups. However, dead cell ratios of Monostroma nitidum thalli were increased from 0~4.6% to 99.0~100% after the treatment. Bathing Porphyra thalli in activating treatment agent resulted in a great decrease in epiphytic bacterial number attached to the thalli from $10^2{\sim}10^{11}$ cells/g to $0{\sim}10^5$ cells/g but did not change the colour of the thalli. These results suggest that bathing Porphyra thalli in activating treatment agent could be a promising strategy to remove green algae, diatoms and bacteria.

• Applied Biological Chemistry
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• v.37 no.6
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• pp.480-486
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• 1994

The present series of investigations have been undertaken to know the effective removal method of some pesticides, heavy metals and detergent when the doses of oxidants and coagulant were changed in the treatment process of drinking water containing organic material. Three pesticides, IBP, diazinon and CNP, were removed by about 68 to 100% by treatment of oxidant, $Cl_2$. Especially, diazinon was completely removed by treatment of $Cl_2$ and other oxidants such as $Cl_2,\;KMnO_4\;and\;O_3$. However, butachlor removal measured only 20.3 to 26.7% due to treatment of all oxidant used. A detergent, sodium dodecylbenzenesulfonate, was effectively removed by treatment of $O_3$ but remained stable in the presence of other oxidants. The heavy metals of Cd, Pb, Cu and Zn in water were not affected by treatment of all oxidants used. By changing the concentration of humic matter and the dosage of coagulant, the removal of heavy metals was increased according to the increase of coagulant dosage, and decreased when increasing the concentration of humic matter, whereas the pesticides and detergent were not effectively removed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.287-290
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• 2002

계면활성제를 이용한 유류 오염토양 복원기술 적용시 발생되는 세척 유출수를 유류분해 미생물로 알려진 Pseudomonas putida Fl, Pseudomonas oleovorans, Acinetobacter calcoaceticus를 이용하여 생물학적으로 처리하는데 필요한 기초 연구를 실시하였다 세종류의 미생물은 본 연구에 사용된 계면활성제(POE$_{5}$, POE$_{14}$)에 대하여 독성이 없는 것으로 판명되었으며, 배양 종료 후 계면활성제 농도에 따른 TPH 분해율은 0.1%, 0.5%, 1%의 계면활성제 농도에서 유사한 분해율을 나타냈으나, 배양 초기에는 0.1%가 0.5%나 1% 농도에 비하여 높은 분해율을 보였다 pH의 변화에 따른 TPH 분해율은 적용 pH 범위(4, 6.5, 9)내에서 모두 생육이 가능하였으며, 세 종류의 미생물은 pH 6.5에서 가장 높은 TPH 분해 율을 나타내었다.

• 월간 기계설비
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• s.257
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• pp.64-68
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• 2011

현행 건설일용근로자의 포괄임금 계약에 대한 대법원의 판결과 고용노동부의 지침이 변경되어 혼란이 야기되고 있다. 고용노동부는 지난 8월 8일 건설 일용근로자의 포괄임금제 업무처리 지침을 변경하고 일선 사업장에 시정 지시 공문을 발송하고 있다. 새로 변경된 건설 일용근로자의 포괄임금제 업무처리 지침은 일당제 일용근로자의 고용형태를 두 가지로 구분하여 일급에 포함되었다고 볼 수 있는 수당과 그렇지 않은 수당을 명시하고 있다. 일급에 포함되었다고 볼 수 없는 수당의 경우 해당 근로수당을 포함하여 체결된 근로계약이 부적정하다는 입장이며, 이에 따라 일당제 일용근로자를 사용하고 있는 사업장에 시정지시를 하고 있다는 것이다. 그러나 현행 판례 및 행정해석, 기존 고용노동부의 지침은 제수당을 미리 합산한 일정금액을 지급하기로 하는 포괄임금 계약을 인정하고 있다. 이처럼 판례와 고용노동부의 지침이 서로 다르고, 새로 변경된 고용노동부의 지침을 반영하는 새로운 판례가 아직까지 나오지 않았기 때문에 사업장에서는 사례별로 유연한 대응이 필요하다.