• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.1
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• pp.49-59
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• 2024

Biodegradable coating urea plays an important role in reducing the non-pollutants in agroecosystems, maximizing the plant nutrient utilization efficiency and slow-releasing nitrogen. Herein, the objective of this study was to investigate the nitrogen-releasing patterns and greenhouse gas emissions on different biodegradable coating urea. The treatments consisted of the control as an application of chemical fertilizers, NBCF as the non-biodegradable coating urea, NB60, and MDS as biodegradable coating urea. As a result of this study, the maximum accumulated total nitrogen (TN) concentration in the NBCF was higher at 33% than one in the NB60 during the precipitation periods. Its leaching period in the NCBF was prolonged for day 10 compared to the NB60. TN and NO₃-N releasing patterns in the NBCF and NB60 were fitted well on linear types(R²≥0.991), but their control and MDS were fitted well on Sigmoid curves(R²≥0.994) with high releasing concentration in the MDS compared to the control during leaching periods. For the greenhouse gas emissions, CH₄ emissions in the NBCF, NB60, and MDS were increased at 0.38%, 11.36%, and 5.91%, and N₂O emissions were also increased at 50.5%, 32.4%, 58.8% as compared to the control, respectively. Therefore, application of biodegradable polymer coating urea might mitigate the non-point pollutants in agro-ecosystem.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.3
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• pp.311-321
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• 2007

Nowadays, concerns have much more growing regarding indoor air quality (IAQ) on the public transportation including railway vehicles. Last year Korea Ministry of Environment (ME) set new guideline for public transportation. In this study several factors were analyzed which may affect comfortableness of railway passenger cabin, and we monitored IAQ parameters (PM10, CO, $CO_2$, VOCs, temperature and humidity) to investigate the present pollution in passenger cabin. In general, the railway air quality was satisfactory. The PM10 and $CO_2$ level on all passenger cabin were below the new guideline level 1 for PM10 $(200{\mu}g/m^3)\;and\;CO_2(2,000ppm)$. Clustering method was carried out to classify the air polluting pattern of the cabin. As a result, the pollutants could be classified to 4 clusters and the origin of pollution is soil, diesel exhaust gas, abrasion of rail and plume.

• Journal of Dairy Science and Biotechnology
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• v.33 no.3
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• pp.171-177
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• 2015

In March 2015, the milk quota system in Europe that had lasted for more than 30 years was abolished to improve the competitiveness of the European dairy sector in the international market. Despite an increase in the consumption of dairy products in Europe, the milk price is expected to stabilize in the next decade after a decrease between 2015 and 2016. This stabilization of prices will be caused by a significant increase in production, with the proportion exceeding domestic demand to be exported. In the international market, the price of milk will reduce in the next decade, leading to a restructuring of the milk sector with a lower number of farms, but with higher production and efficiency. Mountain farms will follow the same trend, although these farms play an important social role by providing ecosystem services such as maintaining cultural services, reducing greenhouse gas emissions, promoting soil stability, and improving the aesthetic value of the landscape. Nevertheless, they remain at a disadvantage compared with lowland farms. To prevent the loss of mountain farms, there is thus a need to valorize the ecosystem services that they provide and promote the processing of milk into certified products of high quality.

• Explosives and Blasting
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• v.28 no.1
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• pp.40-54
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• 2010

The messer shield method applys mainly to a tunnel with small cross-section of a weathered soil or weathered rock district and is fulfilled mostly by man-power excavation. but in case that hard rock exposes on tunnel face, incredible is an application of the rock-splitting method using a hydraulic power or a blasting method. This study represents the case of a blasting method which can control to be practiced by the minimum charges of 125 g an initial vibration occurring at the cut instead of the rock-splitting method, even though water pipe and gas pipe are closely adjacent.

• Korean Journal of Organic Agriculture
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• v.9 no.1
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• pp.17-27
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• 2001

To clarify the proper and safe duration of maturation periods for sawdust-pig manure composts, leaf lettuces were applied with pig manure composts fermented for 15, 30, 45, 60, 75 days and 1 year (control) and cultivated in a plastic house with or without additional PE film tunnel. The changes in physiochemical properties of soil and leaf lettuce growth were measured. Shorter duration of maturation periods enhanced the generation of N $H_3$ gas from the composts and resulted in significant decrease in seed germination, growth and yield of leaf lettuce. Under with and without PE tunnel conditions the concentration of N $H_3$ from compost over 3.8 and 2.1 mg/100g composts, respectively induced growth reduction. In proportion to the increase of maturation duration saw-dust containing pig manure exhibited decrease in C/N ratio, N $H_4^{+}$-N, N $H_4^{+}$N $O_3^{-}$ ratio but increase in N $O_3^{-}$-N contents. In case of applying pig manure compost without PE film tunnel condition the minimum maturation period of pig manure composts for safe leaf growth was 60 days, while minimum 75 days of maturation was required when applied with PE film tunnel. tunnel.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.96-100
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• 1992

The microbiological degradation of 2-(2-methyl-4-chloro-phenoxy) propionic acid (MCPP) was evaluated using mixed cultures of soil bacteria. The mixed cultures comprised Pseudomonas species, Flavobacterium species, and Achromobacter species. The bacteria used MCPP as the sole source of carbon and energy but only a partial degradation of the parent compound occurred MCPP degradation proceeded via the formation of 2-methyl-4-chlorophenol (2, 4-MCP) which was detected by high pressure liquid chromatography (PHLC) and confirmed by gas chromatography-mass sepctrometry. This intermediate occurred only transiently and no evidence was seen for the presence of other intermediates detectable by the reverse-phase HPLC or UV absorbance.

• Journal of Environmental Impact Assessment
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• v.10 no.2
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• pp.99-108
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• 2001

This study was performed to develop an information processing system for the sound conservation of soil and groundwater resources. The system contains numerical models and geographic information systems for underground flow and contamination. Multidimensional Finite Element Model for Subsurface Environment (MFEMSE) was invented to analyze underground flow and pollution problems of water and gas phases. Newly developed and conventional models (MODFLOW, MOC3D, MT3D, PMPATH, PEST, UCODE) were integrated with GIS (ArcView) for the construction of an integrated information management system of subsurface environment. This system was applied to the management of three mineral water companies located in clean high mountain basin. Desirable management criteria and operational strategies were suggested using this system. The system was constructed to be applied for the broad sense of decision supporting tools in related topics of this study, so that it can be used not only for the prevention regulations, but also for clean up projects.

• Ocean Systems Engineering
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• v.4 no.3
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• pp.215-241
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• 2014

Steel catenary riser (SCR) is a popular/economical solution for the oil/gas production in deep and ultra-deep water. The behavioral characteristics of SCR have a high correlation with the motion of floating production facility at its survival and operational environments. When large motions of surface floaters occur, such as FPSO in 100-yr storm case, they can cause unacceptable negative tension on SCR near TDZ (touch down zone) and the corresponding elastic deflection can be large due to local dynamic buckling. The generation, propagation, and decay of the elastic wave are also affected by SCR and seabed soil interaction effects. The temporary local dynamic buckling vanishes with the recovery of tension on SCR with the upheaval motion of surface floater. Unlike larger-scale, an-order-of-magnitude longer period global buckling driven by heat and pressure variations in subsea pipelines, the sub-critical local dynamic buckling of SCR is motion-driven and short cycled, which, however, can lead to permanent structural damage when the resulting stress is greatly amplified beyond the elastic limit. The phenomenon is extensively investigated in this paper by using the vessel-mooring-riser coupled dynamic analysis program. It is found that the moment of large downward heave motion at the farthest-horizontal-offset position is the most dangerous for the local dynamic buckling.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1740-1746
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• 2006

Enrichment techniques led to the isolation of a Pseudomonas sp. strain P2 from municipal waste-contaminated soil sample, which could utilize different isomers of a commercial mixture of 4-nonylphenol when grown in the presence of phenol. The isolate was identified as Pseudomonas sp., based on the morphological, nutritional, and biochemical characteristics and 16S rDNA sequence analysis. The ${\beta}$-ketoadipate pathway was found to be involved in the degradation of phenol by Pseudomonas sp. strain P2. Gas chromatography-mass spectrometric analysis of the culture media indicated degradation of various major isomers of 4-nonylphenol in the range of 29-50%. However, the selected ion monitoring mode of analysis of biodegraded products of 4-nonylphenol indicated the absence of any aromatic compounds other than those of the isomers of 4-nonylphenol. Moreover, Pseudomonas sp. strain P2 was incapable of utilizing various alkanes individually as sole carbon source, whereas the degradation of 4-nonylphenol was observed only when the test organism was induced with phenol, suggesting that the degradation of 4-nonylphenol was possibly initiated from the phenolic moiety of the molecule, but not from the alkyl side-chain.

• Microbiology and Biotechnology Letters
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• v.25 no.5
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• pp.520-526
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• 1997

Bacterial strains which degrade Arabian Light crude oil were isolated by enrichment culture from oil-spilled soil. The strain A54 was finally selected after testing emulsifying activity and oil conversion rate. Strain A54 was identified as a Acinetobacter sp. based on the morphological, biochemical and physiological characteristics. It appears to be highly specialized for growth on Arabian Light crude oil in minimal salts medium since it showed preference for oil or degradation products as substrates for growth. It was found that it could grow on at least fifteen different hydrocarbons. The optimum cultural and environmental conditions were as follows; 25$\circ$C for temperature, 7,5 for pH, 2.0% for NaCl concentration and 2.0% for crude oil concentration. Additionally, the optimal concentration of NH$_{4}$NO$_{3}$, and K$_{2}$HPO$_{4}$, were 12.5 mM and 0.057 mM, respectively. Cell growth and emulsifying activity as a function of time were also determined. Crude oil degradation and the reduction of product peaks were identified by the analysis of remnant oil by gas chromatography. Approximately 63% of crude oil were converted into a form no longer extractable by mixed organic solvents.