• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1233-1237
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• 2001

A study was conducted to determine the effects of maturity at harvest and wilting days on the quality of round baled rye (Secale cereale L.) silage. This study was a $3{\times}3$ factorial arrangement in a split plot design with 3 replicates. The main plot was 3 harvesting dates at the stage of boot (20 Apr.), heading (29 Apr.) and flowering (14 May). The subplot was wilting day : 0 (unwilted), 0.5 and 1 day (0, 1, and 2 days at boot stage). Acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents of rye silage were significantly greater than those of rye before ensiling, but crude protein (CP) content and in vitro dry matter digestibility (IVDMD) were vice versa. Buffering capacity (BC) of rye harvested at flowering stage was decreased from 264 to 202 meq/kg at 1 day wilting, however, it was increased when harvested at boot or heading stage. The pH in wilted silage was the highest while that of flowering stage was the lowest. Water soluble carbohydrate (WSC) content of wilting rye was lower than that of unwilted, and the lowest at late harvesting stage. All plots had minimal WSC content for silage fermentation. Wilting treatment and delayed harvesting date caused an increase in dry matter (DM) content of round bale silage. The content of ammonia-N expressed as a portion of total N showed negative correlation with DM content. High quality silage according to ammonia-N content could be obtained from mid-harvest with wilting. There were highly significant differences in each organic acid between harvesting dates and wilting periods. Acetic and butyric acid contents were increased with delayed harvesting and prolonged wilting period, the lactic acid content, however, was decreased. This study demonstrated that harvest of rye from heading to flowering stage with wilting would be a recommendable method for making high quality rye silage using round bale system.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.18-27
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• 2006

Air Sparging (IAS, AS) is a ground-water remediation technique, in which organic contaminants are volatilized into air as they rise from saturated to vadose soil zone. This study was conducted to investigate the variation characteristics of TPH, VOCs and $CO_2$ for air sparging of diesel contaminated saturated soil. Initial TPH concentration was 10,000 mg/kg for saturated soil phase and 1,001 mg/L for soil aquifer phase. After 36 days of air sparging, the equilibrium temperature of 2-Dimension experiment system was $24.9{\pm}1.5^{\circ}C$. The saturated soil TPH concentration (in the C10 port close to air diffuser) was reduced to 66.0% of the initial value. The mass amount of $CO_2$ was 3,800 mg and 3,200 mg in air space (C70 port) and in unsaturated soil zone (C50 port), respectively. The VOCs production kinetic parameter was 0.164/day in the air space (C70 port) and 0.182/day in the unsaturated soils (C50 port).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.387-393
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• 2005

The effect of cattle manure with the rates of 2 and 4 ton $l0a^{-1}$ for winter rye and summer corn cultivation, respectively, on the dry matter (DM) yield and nitrogen (N) uptake were investigated during successive three­year conversion period from paddy to upland condition in paddy field. The changes in soil properties and soil N sup­plying capacity during repetitive manure application were a1so examined. Growth and DM yield of upland forage crops, especially. winter rye were hindered highly by poor soil condition in the first year after conversion from paddy to upland condition, so apparent recovery of cattle manure N by crops was very low in the first conversion year. But, DM yield and N uptake of upland forage crops were increased linearly by accumulative input of cattle manure along with mineral N enrichment in soil, which also increased apparent recovery of cattle manure-No It seemed that those increases were mainly due to the improvement of soil properties such as soil mineral N, soil organic matter (soil carbon), potentially mineralizable N and bulk density by accumulative input of cattle manure rather than the increase of soil N supply according to accumulative conversion period from paddy to upland condition. It was derived that conversion period from paddy to upland condition over 2 years is needed to obtain proper DM yield in paddy field and accumulative inputs of cattle manure during the conversion period is more influential to the continuous increment of DM yield and N uptake of upland crop as well as of potential N supplying capacity of soil.

• Journal of Korea Port Economic Association
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• v.34 no.2
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• pp.17-30
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• 2018

The regional industry promotion system, which seeks to link the characteristics and resources of the region to its core strategic industry, is spreading the industrial resources in the form of an organic network. The Seosan-Daesan Port is the only port in the Chungcheong provinces that is equipped with international passenger dock and terminal, and it will soon have a ferry service operating to the Longyan port in Rongcheng, China in 2018. The study focuses on effects of the first international ferry operation in the provinces that are being realized with the aim of developing the regional industry. The study also analyzes the ripple effects on the tourism and port industries in the provinces by tapping into the 2013 regional inter-industry table. The analysis shows that the scheduled ferry operation will generate 47,815 million won in production and 23,423 million won in added value for the region's tourism industry. It will also generate total revenue of 12,567 million won for the port industry driven by the locally handled freight containers and the added value. Currently, the Korea-China ferry operation in other regions exhibits greater dependence on the cargo than the passengers. Thus, for the international ferry operation to and from Seosan, generating maximum employment in tourism from the passengers of the international ferry operation will require strategic marketing to attract tourists. At the same time, a steady supply of cargo needs to be sustained by maintaining a balance between import and export cargoes. Furthermore, greater efforts should be made to create more sea routes than other regions or to increase voyages for the purpose of generating more added value.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.57-65
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• 2014

Spatial and temporal distributions of zooplankton were measured in an oligotrophic pumped storage-type hydroelectric reservoir which was composed of two reservoirs exchanging water daily, with water going up at night and going down during the day. Repetitive diel disturbance of the water column can be a unique feature of this reservoir system. Chl-${\alpha}$ concentration was highest in the early winter season. Phytoplankton density was lower in summer monsoon due to high flushing rate on rainy days. The zooplankton density was higher in the smaller upper reservoir possibly due to lower fish density in the upper reservoir. In the seasonal variation a time gap was observed between the phytoplankton bloom and the zooplankton bloom (particularly a rotifer, Keratella cochlearis). It is likely to that Keratella production is partially supported by heterotrophic food sources than phytoplankton. The dominance of a mixotrophic dinoflagellate (Peridinium bipes f. ocultatum) might have complicated the trophic relationship between phytoplankton and zooplankton. Our results provide some ecological information of zooplankton community in a highly disturbed alpine reservoir ecosystem relying on mostly allochthonous organic matter.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.417-423
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• 2018

It analyzed the efficiency of the runoff reduction of artificial reservoir by analyzing the influent and effluent of reservoir located downstream of the livestock area. Production of non point pollutants in livestock feeding areas, which is located at steep slope land, was mainly due to first flushes. Suspended Solid concentration of influent increased due to amount of rainfall, and T-P also increased over four times and 30 % of total nitrogen increased on average compared to those of dry season. While the concentration of nitrate nitrogen showed little variation, ammonia nitrogen increased over two times. The storage style nonpoint reduction facility showed the highest removal efficiency of 53 % for total phosphorus in dry weather, when the removal efficiency was 37 % for suspended solids, 10% for organic compounds, and 5 % for total nitrogen. Since algal bloom grows due to eutrophication in summer, the minus removal efficiencies of nitrogen concentration through the reservoir occurred with high frequency. Removal efficiency decreased during rainfall, showing 60 % for supended solids, and 22 % for total phosphorus. While having over nine times of capacity than the standard of non-point removal facility from Ministry of Environment, it was impounded with water during rainy season, showing not enough nonpoint removal efficiency, which indicates that maintenance is also an important factor to the nonpoint removal efficiency.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.302-307
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• 2014

To examine the trophic ecology of the ascidian Styela clava in an aquaculture system of Korea, stable carbon and nitrogen isotopes were analyzed monthly in S. clava, coarse ($>20{\mu}m$, CPOM) and fine particulate organic matters ($0.7<<20{\mu}m$, FPOM). CPOM (means: $-18.5{\pm}1.2$‰, $9.3{\pm}0.7$‰) were significantly higher ${\delta}^{13}C$ and ${\delta}^{15}N$ values than those ($-20.5{\pm}1.5$‰, $8.4{\pm}0.5$‰) of FPOM. S. clava had mean ${\delta}^{13}C$ and ${\delta}^{15}N$ values of $-18.9({\pm}1.7)$‰ and $11.6({\pm}0.7)$‰, respectively. S. clava were more similar to seasonal variations in ${\delta}^{13}C$ and ${\delta}^{15}N$ values of FPOM than those of CPOM, suggesting that they rely largely on the FPOM as a dietary source. In addition, our results displayed that the relative importance between CPOM and FPOM as dietary source for the ascidians can be changed according to the availability of each component in ambient environment, probably reflecting their feeding plasticity due to non-selective feeding irrespective of particle size. Finally, our results suggest that dynamics of pico- and nano-size plankton (i.e., FPOM) as an available nutritional source to S. clava should be effectively assessed to maintain and manage their sustainable aquaculture production.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.309-316
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• 2012

This study was performed to investigate the effects of forage cropping system and cattle slurry on productivity of whole crop rice, whole crop barley and Sorghum-Sudangrass hybrid and environmental pollution in paddy land. Forage cropping system used in this study was consisted of double-cropping whole crop barley followed by whole crop rice applied with cattle slurry (DWBRC) and double-cropping whole crop barley followed by Sorghum-Sudangrass hybrid applied with cattle slurry (DSSBC). The field experiments were conducted on the clay loam at Backsanmyun, Kimje, Chunlabukdo province in Korea for three years (May 2006 to Apr. 2009). This study was arranged in completely randomized design with three replicates. The field had been sown with whole crop rice 'Nampyung', Sorghum-Sudangrass hybrid 'Sordan79' and whole crop barley 'Younyang'. The yields of whole crop barley in DWBRC and DSSBC were 7,515 kg/ha and 8,515 kg/ha, respectively. The yields of whole crop barley in DSSBC significantly increased as compared with that of DWBRC (p<0.05). The contents of crude protein, neutral detergent fiber (NDF), acid detergent fiber (ADF), total digestible nutrient (TDN) of whole crop barley in DWBRC were not difference as compared with those of DSSBC. The pH, and contents of total nitrogen and organic matter in soil samples collected at the end of the experiment increased as compared with those at the beginning of the experiment (p<0.05). However, The content of phosphate in DWBRC was no difference as compared with DSSBC. In addition, after the end of experiment, the concentrations of exchangeable cations (Ca, Na, Mg and K) in soil samples collected at the end of the experiment were remarkably higher than those at the beginning of the experiment (p<0.05). The concentrations of $NH_4$-N, $NO_3$-N, $PO_4$-P, Cl, Ca, K, Mg and Na in leaching water were hardly influenced by the cropping system and application of cattle slurry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.139-147
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• 2021

Livestock manure is used as an organic fertilizer to replace chemical fertilizers after sufficient fermentation in an aerobic bioreactor. On the other hand, liquid manure disposal problems occur repeatedly because soil spraying is restricted during the summer when the crops are growing. To use liquid fertilizer (LF) as an additional nutrient source for crops, it is necessary to reduce the amount of suspended solids (SS) in the liquid fertilizer and secure stability problems against pathogenic microorganisms. This study examined the effects of the simultaneous SS removal and E.coli sterilization in the LF using the microbubble (MB) generator (FeMgO catalyst insertion). The remaining SS were further removed using the integrated microbubble and microfilter system. During the floating process in the MB device, the SS were removed by 57.9%, and the coliform group was not detected (16,200→0 MPN/100 mL). By optimizing the HRT of the integrated system, the removal efficiency of the SS was improved by 92.9% under the 0.1h of HRT condition. After checking the properties of the treated LF, 64.5%, 70.1%, 54.9%, and 51.5% of the TCOD, SCOD, PO4-P, and TN, respectively, were removed. The treated effluent from such an integrated system has a lower SS content than that of the existing LF and does not contain coliforms; therefore, it can be used directly as an additional fertilizer.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.414-418
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• 2012

The quantity of research on microbial fuel cells has been rapidly increasing. Microbial fuel cells are unique in their ability to utilize microorganisms and to generate electricity from sewage, pig excrement, and other wastewaters which include organic matter. This system can directly produce electrical energy without an inefficient energy conversion step. However, with MFCs maximum power production is limited by several factors such as activation losses, ohmic losses, and mass transfer losses in cathodes. Therefore, electron acceptors such as nitrate and ferric ion in the cathodes were utilized to improve the cathode reaction rate because the cathode reaction is very important for electricity production. When 100 mM nitrate as an electron acceptor was fed into cathodes, the current in single-cathode and dual-cathode MFCs was noted as $3.24{\pm}0.06$ mA and $4.41{\pm}0.08$ mA, respectively. These values were similar to when air-saturated water was fed into the cathodes. One hundred mM nitrate as an electron acceptor in the cathode compartments did not affect an increase in current generation. However, when ferric ion was used as an electron acceptor the current increased by $6.90{\pm}0.36$ mA and $6.67{\pm}0.33$ mA, in the single-cathode and dual-cathode microbial fuel cells, respectively. These values, in single-cathode and dual-cathode microbial fuel cells, represent an increase of 67.1% and 17.6%, respectively. Furthermore, when supplied with ferric ion without air, the current was higher than that of only air-saturated water. In this study, we attempted to reveal an inexpensive and readily available electron acceptor which can replace platinum in cathodes to improve current generation by increasing the cathode reaction rate.