• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1180-1185
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• 2006

Lab-scale batch experiments using several 25-L transparent acrylic reactors were conducted to develop optimum capping materials that can reduce phosphorus released from polluted sediments. The sediment used in the experiment was very fine clay(8.8 $\Phi$ in mean grain size), and organic carbon($C_{org}$) content was as high as 2%. Four kinds of batches with different capping materials Brucite($Mg(OH)_2$), Sea sand($SiO_2$), Granular-gypsum($CaSO_4{\cdot}2H_2O$), Double layer(brucite+sand), and one control batch were operated for 30 days. Phosphorus fluxes released from bottom sediments in the control batch were estimated to be 14.6 $mg{\cdot}m^{-2}{\cdot}d^{-1}$, while 9.5 $mg{\cdot}m^{-2}{\cdot}d^{-1}$, 5.2 $mg{\cdot}m^{-2}{\cdot}d^{-1}$, 4.2 $mg{\cdot}m^{-2}{\cdot}d^{-1}$, and 3.1 $mg{\cdot}m^{-2}{\cdot}d^{-1}$ in the batch capped with Sea sand, Granular-gypsum, Double layer, and Brucite, respectively. The results obtained from lab-scale batch experiments show that there were 70% reduction of phosphorus for some materials such as Brucite, Double layer(brucite+sand), and whereas sea sand only about 35%. The pH range of surface sediment to which Brucite was applied showed about $8.0{\sim}9.5$ in the weak alkaline state. This effect can prevent liberation of $H_2O$. The addition of gypsum into the sediment can reduce the progress of methanogenesis because of fast early diagenesis and sufficient supply of $SO_4^{2-}$ to the sediments, stimulate the SRB highly. Therefore, the application of Brucite and Gypsum can reduce phosphorus release from the sediment as a result of formation of $Mg_5(OH)(PO_4)_3$, pyrite($FeS_x$), and apatite-mineral.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.304-309
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• 2011

BACKGROUND: Generally, water plants may play an important role in nutrients(N, P) removal in constructed wetlands(CWs). Previous studies considered nutrients uptake by water plants in various CWs for treating point source pollution. On the other hand, few studies considered nutrients uptake by water plants in free water surface(FWS) CWs for treating non-point source pollution. METHODS AND RESULTS: To investigate characteristics of nutrient uptake by water plants in FWS CWs, dry weights, nutrients content and nutrients uptake by water plants were investigated from April, 2008 to October, 2008. Dominance plants were Phragmites japonica STEUD (PHRJA), Nymphaea tetragona ANGUSTA(NTMTE), Typha orientalis PRESL(TYHOR), Phragmites communis TRINIUS(PHRCO) and Zizanis latifolia TURCZ(ZIZLA) in FWS CWs. The dry weights of water plants in August were higher in the order of TYHOR(54.27 g/plant) > PHRJA(44.30 g/plant) ${\geqq}$ PHRCO(39.60 g/plant) ${\geqq}$ ZIZLA(37.80 g/plant) ${\fallingdotseq}$ NTMTE(36.75 g/plant). The T-N and T-P contents by water plants were not significantly differences regardless of cultivation period. The maximum amount of T-N uptake by water plants in August were 773 mg/plant for PHRJA, 625 mg/plant for NTMTE, 1206 mg/plant for TYHOR, 754 mg/plant for PHRCO and 768 mg/plant for ZIZLA. The maximum amounts of T-P uptake by PHRJA, NTMTE, TYHOR, PHRCO and ZIZLA were 397, 177, 411, 261 and 229 mg/plant in August, respectively. CONCLUSION(s): The results of this study suggest that optimum water plant was Typha orientalis PRESL in free water surface constructed wetlands.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.227-234
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• 2004

This experiment was conducted at Cheonan Yonam Experimental Livestock Farm in 2001-2002 to detennine the effect of harvest date(20 April, 26 April and 4 May) on forage yield and quality of rye varieties of three different maturing groups(early maturing variety = ‘Koolgrazer’ midseason maturing variety = ‘Horni122’ and late maturing variety = ‘Danko’). The heading date of Kooigrazer, Hornil22 and Danko were 17, 22 and 29 April, respectively. Dry matter percentage increased from 15.6 to 21.6% as the harvest date was delayed from April 20 to May 4. Among the rye varieties tested, dry matter percentage of Koolgrazer, Hornil22 and Danko were 20.9, 18.8 and 16.3%, respectively. Dry matter yield increased from 1l.2 to 13.9 ton/ha as the harvest date was delayed, but no significant difference among rye varieties. As the harvest date was delayed, total digestible nutrients(TDN) yield also increased significantly from 7.4 to 8.4 ton/ha However no significant difference was found among rye varieties. Crude protein(CP) percentage decreased from 20.3 to 17.1% as the harvest date was delayed, and CP percentage of late maturing variety, Danko, was significantly higher than that of the other varieties. In content of fiber component(NDF, ADF, ADL, hemicellulose and cellulose) of rye, the late harvest date(4 May) showed the highest among harvest dates. From comparisoo within rye varieties tested, Kooigrazer, a early maturing variety had higher than a rnidseason and late maturing varieties, Hornill22 and Danko. The cellulase digestible of organic matter of dry matter(CDOMD) decreased as the harvest date was delayed. Among the rye varieties tested, the CDOMD of a early maturing variety, Koolgrazer was the lowest. Our study differences of winter rye in forage yield and quality resulting from variety maturity and harvest stage. A early maturing variety, Kooigrazer should be harvested between 24 and 28 April, Hamill 22(midseason maturing variety) harvested between 29 April and 3 May, Danko(late maturing variety) harvested between 4 and 8 May for maximum forage yield and optimum quality.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.1
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• pp.47-58
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• 2002

Much of the plastic film house soils in the southern part of the Korean peninsula are managed using a upland-paddy rotation culture system (hereafter, RS) to prevent salt accumulation in soil. However, information on the effects of RS on soil properties and environmental conservation is limited. In order to determine the effects of RS on soil properties, 22 fields under RS and 20 fields under a non-rotation system (hereafter, NRS) in plastic film houses were selected in Chinju, in southern Korea, and the P distribution characteristics were investigated, including the chemical properties. The RS contributed to the removal of water-soluble salts in the surface layer and to the redistribution of organic matter evenly in the soil profile. In the AP horizon, available phosphorus levels were $1,611mg\;kg^{-1}$ in RS and $1,789mg\;kg^{-1}$ in NRS, which markedly exceeds the optimum range for plant cultivation. Total P was lower in RS (average $4,593mg\;kg^{-1}$) than in NRS (average $5,440mg\;kg^{-1}$) and this decrease was taken to be an effect of RS. Inorganic P was the predominant form of P in both systems, followed by organic P and residual P. A soil profile showed that total and inorganic P concentrations decreased with depth in both systems. However, organic P increased withdepth in RS, which was in contrast to that noted in NRS. The increase in organic P with depth in RS implied that organically rather than inorganically derived phosphate moved through the soil. The concentrations of water-soluble P, Ca-P and Al-P were higher in NRS than in RS soil profiles, but the Fe-P concentration was higher in RS than in NRS, which might be affected by the anaerobic conditions found in paddy soils. In both systems, the Al-P form of extractable P predominated in the surface layer, followed by Ca-P, Fe-P and water-soluble P. With increasing depth, the composition rate of Ca-P to extractable P decreased to less than 10% in the 60-70cm depth, as Fe-P dominated at this level. The content of water-soluble P, potentially the main source of eutrophication, was higher in NRS than in RS. These results indicated that the RS used in plastic film houses contributed to the removal of water-soluble salts but only slightly decreased the phosphate concentration.

• Journal of Plant Biotechnology
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• v.38 no.3
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• pp.221-227
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• 2011

This study was carried out to determine optimal medium conditions for mass propagation by bioreactor culture of ever-bearing strawberry (Fragaria ${\times}$ ananassa D.). Two different type of nitride were that mixed $NH_4NO_3$ and $KNO_3$ or added $KNO_3$ only. And nitride concentrations were at the 4 levels of $1/2{\times}$, $1{\times}$, $2{\times}$ and $3{\times}$ that was included $NH_4NO_3$ and $KNO_3$. Sucrose content ranged at 3 levels of $10g{\cdot}L^{-1}$, $20g{\cdot}L^{-1}$ and $30g{\cdot}L^{-1}$ and medium pH were at the 3 levels of 4.6, 5.6 and 6.6. In bioreactor culture, medium that are included $NH_4NO_3$ and $KNO_3$ together in MS medium was suitable for mass propagation. Medium EC rose rapidly when the nitride concentration was increased. For that reason, plantlet growth was inhibited. Shoots of nitride $1/2{\times}$ concentration was 10.8 ea and $1/2{\times}$ concentration was suitable for shoot propagation. Fresh weight of sucrose $30g{\cdot}L^{-1}$ was 3,101 mg which was heaviest and aerial and ground part were higher than the other concentration. Shoots were increased in proportion to the increasing concentration of sucrose. In the pH condition, from pH 5.6 to 6.8 were appropriate for the optimum growth of aerial and ground part of plant. From the results, in bioreactor culture for mass propagation, MS medium was suitable $1/2{\times}$ concentration that was included $NH_4NO_3$ and $KNO_3$ together, and added $30g{\cdot}L^{-1}$ of sucrose, and then adjusted pH between 5.6 and 6.6.

• The Korean Journal of Food And Nutrition
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• v.27 no.1
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• pp.22-30
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• 2014

In this study, purple sweet potato bread was prepared by the addition of 0.005%, 0.010%, 0.015% and 0.020% hemicellulase. It's effect on product quality and consumer evaluation were examined. The results showed that the dough pH and total titratable acidity were not significantly different between samples. In the fermentation power of dough expansion, a 0.015% addition sample was the highest between the samples. The bread pH decreased significantly as hemicellulase was increased, whereas. Bread total titratable acidity was significantly decreased. The addition of hemicellulase samples were significantly higher in specific volume and baking loss than the control sample. The moisture content was not significantly different between samples. In colors, the lightness of the control sample was the highest, the redness of the 0.020% addition sample was the lowest while the yellowness of the control was the lowest. The hardness and the fracturability decreased significantly as hemicellulase was increased. The resilience indicated reverse effects. In consumer evaluation, the color and softness were not significantly different between samples. And the hemicellulase addition of samples was higher in flavor than that of the control sample. The overall acceptability was the highest at 5.67 with a 0.010% addition sample. According to these results, the addition of 0.010% hemicellulase in purple sweet potato bread would be the optimum level.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.214-220
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• 1993

Browning of ascidian, Halocynthia roretzi, meat occurres very rapidly when skinned off or cut during processing and it resulted the quality loss of fresh frozen, dehydrated or fermented products. In this study, the causes of color development and prevention of browning were experimented. The browning of ascidian meat may be occurred enzymatically by a tyrosinase contained in meat and viscera which acted specifically on L-tyrosine as a substrate rather than on catechol. Activity of the enzyme in viscera was three times higher than in meat. The optimum pH and temperature on the tyrosinase activity of crude enzyme obtained from ascidian was 6.0 and $30{\sim}35^{\circ}C$, respectively. The enzyme was inactivated heating at $80^{\circ}C$ for 3 minutes or $90{\sim}100^{\circ}C$ for 1 minute and it was inhibited by $0.1{\sim}0.5mM$ solutions at ascorbic acid, sodium hydrogen sulfite, cystein, citric acid, cyanide but only sodium hydrogen sulfite treatment was effective to retard such a high content of enzyme as in case of viscera. In practical use for processing of ascidian meat browning was retarded by dipping the viscera removed ascidian meat in 0.2M citric acid for 5 minutes or $0.2\%$ sodium hydrogen sulfite solution for 1 minute resulting in sulfur dioxide residue less than 100 ppm.

• Journal of agriculture & life science
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• v.43 no.5
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• pp.17-25
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• 2009

The purpose of this study was to find out the optimum germination temperature and dehydration period at SMP processing, and applies 3 kind of seed treatment and compares yield with stand establishment of seeds of 12 pepper cultivars. It was showed that all 12 cultivars of nontreated seed does not entirely germinated in $15^{\circ}C$. It was that SMP seed germination rate 77(Yeomyeong)~100% (Deawang) high, and seeds 12 cultivars was tendency high by more than 93% at all temperatures excepting Bugang($35^{\circ}C$, 85%) and Yeomyeong($15^{\circ}C$, 77%). Dehydration condition of result were Gumsure, Dongbang Jonggagip, Hyangchon, Yeomyeong, Kwangbok, Wang by which 3 hours in $45^{\circ}C$ were proper, which 6 hours in $35^{\circ}C$ were proper Manitta, Joyang, and judged that 12 hours in $25^{\circ}C$ were proper in Bugang, Dabotap, Deawang. It was reported that water percentage of moisture content change of pepper seed by dehydration was difference a little in species, but was judged by 3-6 hours in $45^{\circ}C$. There was compared to SMP, Osmopriming, pH control by stand establishment were shown pH control of Hyangchon, Dabotap species was nontreated, osmopriming treatment. Also, Kwangbok species was tendency that stand establishment was low, and Deawang was good than other species. Yield of nontreated of yield day was tendency, and miss planted rate also appeared high for 90 day. There was difference in species, and processing of pH control and osmopriming was not shown stand establishment that is stabilized in all species. SMP processing condition could bring security of stable stand establishment in all species, and was considered that research that was under various environment condition should be proceeded conclusively.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.290-295
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• 1989

An incubation study was conducted to examine the effect of soil pH and temperature on nitrification potential of 8 different soil series applied with no-N and 200 ugN/g soil as a compound fertilizer at 60 % moisture content of maximum water holding capacity for 8 weeks, whose series were ranged from acid to mild alkali as Gopyeong(Jincheon, pH 4.51), Yesan(Jincheon, pH 4.54), Jigog(Eumseong, pH 4.71), Songsan(Goesan, pH 5.01), Angye(Seongju, pH 5.34), Banho(Seongju, pH 5.73), Weongog(Jincheon, pH 5.93), and Banho(Seongju, pH 7.70), respectively. Interrelationship between the nitrifiable and the net $NO_3-N$(N added plot-no-N plot) accumulated in the soil and tobacco yield in the no fertilizer plot were investigated as well. 1. Nitrification response was various according to soil characteristics at each temperature condition showing that nitrifiable $NO_3-N$ values of the soils were much higher at $25^{\circ}C$ than $15^{\circ}C$. And difference of nitrification potential affected by temperature was markedly distinguishable from 2 weeks after incubation and was showing a tendency to reduce with increasing of soil pH. 2. At each temperature condition, net $NO_3-N$ accumulated at 2 and 4 weeks after incubation was positively correlated with soil pH. 3. Tobacco yield in the no fertilizer plot was more highly correlated with the values of nitrifiable and net $NO_3-N$ accumulated at $15^{\circ}C$ similar to soil temperature in rhizosphere of early stage of tobacco growth than those at optimum temperature($25^{\circ}C$).

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.347-352
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• 2011

Environment-friendly agriculture (EFA) are aimed to reduce use of chemical inputs as possible the recycling of resources and the environment while preserving the local resources in the long term to ensure a constant productivity and profitability for producing safe food. This study was conducted to investigate characteristics on soil environment at paddy field of environment-friendly agriculture regions (EFARs) in Honam area. Survey point of EFARs Chungnam, Jeonbuk and Jeonnam, rice bran farming method in two districts, rice bran + snail farming method in eight districts, snail farming method in five districts and ducks farming method in three districts a total of 18 districts were selected. Annual of farming method, friendly-environment certification, amount of applied fertilizer, and history of cultivation to the farm household were surveyed. The content of available phosphate and silicate among the soil chemical properties in EFA paddy field were a little lower than optimum level, and those of agricultural methods fertilized with rice bran were a little lower than those of others. Hardness among the soil physical properties in EFA paddy field were a little lower than conventional practices, and that of agricultural methods fertilized with rice bran were a little lower than those of others. We showed fertilizer recommendation dose about soil nutritional shortages according to fertilization prescriptions index by crops.