• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1103-1112
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• 2020

Objective: To measure whether a microbial additive could effectively improve the fermentation quality of delayed-sealing (DS) silage, we studied the effects of inoculants of lactic acid bacteria (LAB) and cellulase enzyme on microbial populations, ensiling characteristics, and spoilage loss of DS silage of Napier grass in Africa. Methods: Quick-sealing (QS) and DS silages were prepared with and without LAB (Lactobacillus plantarum) inoculant, cellulase enzymes, and their combination. The QS material was directly chopped and packed into a bunker silo. The DS material was packed into the silo with a delay of 24 h from harvest. Results: In the QS silage, LAB was dominant in the microbial population and produced large amounts of lactic acid. When the silage was treated with LAB and cellulase, the fermentation quality was improved. In the DS silage, aerobic bacteria and yeasts were the dominant microbes and all the silages were of poor quality. The yeast and mold counts in the DS silage were high, and they increased rapidly during aerobic exposure. As a result, the DS silages spoiled faster than the QS silages upon aerobic exposure. Conclusion: DS results in poor silage fermentation and aerobic deterioration. The microbial additive improved QS silage fermentation but was not effective for DS silage.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.2
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• pp.9-18
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• 1986

For identification and apportionment of sources emitting particulate matters in environment, the multi-elemental characterization of size-density fractionated particulate matters was carried out. Eight types of samples were tested; soil, flyash released from burning of bunker-Coil, diesel oil, coal, and soft coal, urban road-way dust, urban dust fall, and airborne particulate matter. The fractions of particulate matters obtained by heavy liquid separation methos with a series of dichloromethane-bromoform were then analyzed using atomic absorption spectrophotometry for Ni, Cr, Cu, An, Fe, Al, and Mg. Each sample showed a different concentration profile as a function of density, and a number of useful conclusions concerning characterization of elemental distribution were obtained. From the density distributions of elements in soil, the maximum value was found for all elements in the density range of 2.2 $\sim 2.9g.cm^{-3}$, including the density of $SiO_2$. However, the distribution of metallic compounds with the density lower than $2.2g.cm^{-3}$ was prevalent in urban roadway dust, urban dust fall, and airborne particulate matter. And the density distribution curves of these urban dusts also have the higher distribution at the density of 2.2 - 2.9g.cm^{-3}$, including the density of wind-blown silica. This tendency generally was prevalent in the natural source elements, such as Al, Fe, Mn, and Mg. The maximum values were found in the density ranges of 1.3 $\sim 2.2g.cm^{-3}$ from the density distribution of elements in oil fired flyash. These distributions of anthropogenic source elements, such as Zn, Ni, Cu, and Cr were higher predominately than those of natural source elements. And the higher distribution was found in the density range of $2.2 \sim 2.9g.cm^{-3}$ from the density distribution of elements in coal and soft-coal fired flyash. These distributions showed similar patterns to soil. But anthropogenic source elements somewhat predominated at the density ranges of $1.3 \sim 2.2g.cm{-3} and 2.9g.cm^{-3}$ to soil. Therefore the higher distribution of anthropogenic source elements in the density ranges of $1.3 \sim 2.2g.cm^{-3} and 2.9g.cm^{-3}$ was considered as anthropogenic origin.

• Journal of Environmental Science International
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• v.11 no.9
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• pp.971-977
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• 2002

The isolated strain, Rhodococcus sp. EL-GT was able to degrade high phenol concentrations up to 10 mM within 24 hours in the medium consisting of 5.3 mM $KH_2PO_4$. 95 mM $Na_2HPO_4$, 18mM $NH_4NO_3$, 1 mM $MgSO_4{\cdot}7H_2O$,\;50{\mu}M CaCl_2$,\;0.5 {\mu}M FeCl_3$, initial pH 8.0, temperature $30^{\circ}C$ in rotary shaker at 200 rpm. This strain was good cell growth and phenol degradation in the alkaline pH range range, and the highest in the pH range of 7 to 9. The microorganism was able to grow at the various chlorinated phenols, benzene, toluene, and bunker-C oil. As Rhodococcus sp. EL-GT was good capable of attachment on the acryl media, it would be used as microorganism to consist of biofilm in wastewater treatment.

• Journal of Navigation and Port Research
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• v.28 no.5
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• pp.463-468
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• 2004

A lab-scale fundamental study to develop the solvent extraction process of ship wash wastewater containing TBT was carried out. For various solvents, including diesels for car and ship, bunker B, thinner, toluene, and ether, the extraction efficiencies of TBT from synthetic ship wash wastewater were compared The effect of extraction conditions, such as solvent amount, time and intensity of agitation, and pH, on the extraction efficiency of TBT was evaluated Diesel for ship showed better extraction efficiency of TBT than those of other tested solvents, and the proper amount of the extraction solvent for 1L of the wastewater was l0mL. When the agitation intensity was increased from 50rpm to 250rpm, the TBT remained in the wastewater after the extraction was decreased from around 120ppb to 2.8ppb. The remaining TBT in the wastewater was sharply decreased from 1hr of the extraction time, but was slightly increased again after 5hrs of the extraction time. The efficiency of TBT extraction was good in the weak acid range of pH, but was not significant as much as the others.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.3
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• pp.317-330
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• 2004

The Purpose of this study was to develop the P $M_{2.5}$ source Profiles, which are mass abundances (fraction of total mass) of a chemical species in P $M_{2.5}$ source emissions. The source categories studied were soil, road dust, gasoline and diesel vehicles, industrial source, municipal incinerator, coal-fired power plant, biomass burning, and marine. The chemicals analyzed were ions. elements. and carbons. From this study, soil source had the crustal components such as Si, hi, and Fe. In the case of road dust. Si, OC, Ca, Fe had large abundances. The abundant species were S $O_4$$^{2-}$, C $l^{[-10]}$ , N $H_4$$^{+}$, and EC in the gasoline vehicle and EC, OC, C $l^{[-10]}$ , and S $O_4$$^{2-}$ in the diesel vehicle. The main components were S $O_4$$^{2-}$, S N $H_4$$^{+}$, and EC in the industrial source using bunker C oil as fuel, C $l^{[-10]}$ , N $H_4$$^{+}$, Fe, and OC in the municipal incinerator source, and Si, Al, S $O_4$$^{2-}$, and OC in the coal -fired power plant source. In the case of biomass burning, OC, EC, and C $l^{[-10]}$ were mainly emitted. The main components in marine were C $l^{[-10]}$ , N $a^{+}$, and S $O_4$$^{2-}$.EX> 2-/.

• Journal of Preventive Medicine and Public Health
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• v.42 no.2
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• pp.73-81
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• 2009

Objectives : This study presents a scientific basis for the establishment of an environmental health contingency plan for dealing with accidental coastal oil spills and suggests some strategies for use in an environmental health emergency. Methods : We reviewed the existing literature, and analyzed the various fundamental factors involved in response strategies for oil spill. Our analysis included data derived from Hebei Spirit oil spill and used air dispersion modeling. Results : Spill amounts of more than 1,000 kl can affect the health of residents along the coast, especially those who belong to vulnerable groups. Almost 30% of South Korean population lives in the vicinity of the coast. The area that is at the highest risk for a spill and that has the greatest number of people at risk is the stretch of coastline from Busan to Tongyeong. The most prevalent types of oil spilt in Korean waters have been crude oil and bunker-C oil, both of which have relatively high specific gravity and contain volatile organic compounds, polycyclic aromatic hydrocarbons, and metals. In the case of a spill of more than 1,000 kl, it may be necessary to evacuate vulnerable and sensitive groups. Conclusions : The government should establish environmental health planning that considers the spill amount, the types of oil, and the distance between the spot of the accident and the coast, and should assemble a response team that includes environmental health specialists to prepare for the future oil spill.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.267-282
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• 2012

In this study, RPS system, one of the renewable energy support systems, is utilized for economic analysis of solar generation equipment and the fuel cost savings plan for controlled horticulture farms with high fuel-cost dependency and facility applicability were evaluated. On the exterior of the upper layer of glass greenhouse (9917$m^2$) of controlled horticulture farms using bunker C oil, half of the area (4958$m^2$) was utilized for theoretical installation and operation of 450kW-level solar power generator, and as the result, first, the effect of investment cost only of solar generation system was found to be quite excellent, but it was analyzed that there were limits to saving the fuel costs of the controlled horticulture farms. Second, when geothermal system was first introduced in the farm and solar system was additionally introduced, it was analyzed that the effect of introducing solar system was excellent. In order to apply such effects to the sites of farming, partial supplementation of RPS system which is being uniformly applied regardless of the purpose of renewable energy is necessary. When the subject of use directly install facilities where it is directly connected to national added-value such as food security created by the farming industry, it is necessary to introduce appropriate system that corresponds to such. Moreover, it was studied that the quick development of demonstrative complex that can practically evaluate the applicability of renewable energy in farming industry and interest and preparation of related institutions in financial support structure for its site application would lead to success.

• Journal of Welding and Joining
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• v.35 no.3
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• pp.82-87
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• 2017

Recent trends in shipbuilding and offshore industries are a huge increase in the ship size and the exploration and production of oil and natural gas in the arctic offshore region. High performance steel plates are required by these industrial trends. Also in IMO(International Maritime Organization) has begun to regulate of fuel of ship to environmental protection, therefore it is little bit difficult to use bunker-C oil to working ship. As the problem of environmental change such as global warming is emerged, the operation of the ship is considered to be involved in the environmental change problem, and the regulation of environmental pollution is gradually strengthened. As these environmental regulations are strengthened demand for LNG fuel ships is rapidly increasing. Currently, cryogenic steels used in LNG tanks include aluminum alloy, SUS 304, and 9%-Ni steel. Those steels are has high cost to construction of large LNG carrier. The new materials were suggested several steel mills to decrease construction cost and easy construction. The new cryogenic steel should be evaluate safety to applied real structure include LNG ship. Therefore, in this study, fracture toughness of weld joints were investigated with cryogenic steel for application of LNG tank.

• Journal of Environmental Science International
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• v.16 no.7
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• pp.799-804
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• 2007

Oil spill caused severe effects on the marine fauna and flora due to direct contact of organisms with the oil and even in regions not directly affected by the spill. This study was conducted to understand the effects of the oil spill accidents and the use of dispersant on the red tide of Cochlodinium polykrikoides. Crude oil produced in Kuwait, bunker-C, kerosene and diesel oil, and a chemical dispersant produced in Korea, were added with a series of 10 ppb to 100 ppm in the f/2-Si medium at $20^{\circ}C$ under a photon flux from cool white fluorescent tubes of $100\;mol\;m^{-2}\;s^{-1}$ in a 14: 10 h L:D cycle for the culture of C. polykrikoides. In low concentrations of ${\leq}$ 1 ppm of examined oils no impact on the growth of C. polykrikoides was recorded, while in high concentration of ${\geq}$ 10 ppm, cell density was significantly decreased with the range of 10 to 80% in comparison with the control. The growth of C. polykrikoides after the addition of the dispersant and the mixtures combined with oils and a dispersant of ${\geq}$ 10 ppm appeared to decrease, whereas the growth of C. polykrikoides exposed to ${\leq}$ 100 ppb showed little serious impact. However, almost all the C. polykrikoides cells were died regardless of a dispersant and combined mixtures within a few days after the addition of high concentrations.

• Elastomers and Composites
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• v.39 no.1
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• pp.61-70
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• 2004

This work is about the development or asphalt sealant using the waste edible oil. Asphalt sealant has been used for crack filler and bridge deck joint sealer Several plasticizers such as aromatic or paraffin process oils, DOP, Bunker C fuel oil, and waste edible oil were compounded with the basic components such as asphalt(AP-5), a thermoplastic elastomer(SBS triblock copolymer), a tackifying agent(petroleum resin), and stabilizers. Penetration, softening point, ductility, and elongation by tensile adhesion of those asphalt sealant compounds were measured. Their properties were changed largely depending on both the type and content of plasticizers. Waste edible oil and DOP were the best plasticizers for the low temperature tensile adhesion characteristics. Penetration and elongation by tensile adhesion of asphalt sealant compounds increased with the increase of waste edible oil content and decreased with the increase of talc content. The manufacture of asphalt sealant with low penetration and excellent low temperature tensile adhesion was possible by the recipe optimization.