• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.252-259
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• 2013

BACKGROUND: Salt accumulation in coastal reclaimed soil can decrease plant growth and productivity, which could lead to considerable variation of methane($CH_4$) emission in a rice paddy. The objective of this study was to evaluate the effect of salt concentration on $CH_4$ emission in a coastal reclaimed soil. METHODS AND RESULTS: The effect of salt concentration on $CH_4$ emission and rice growth characteristics was studied by pot test, which packed by reclaimed paddy soils collected from Galsa, Hadong, Gyeongnam province. Electrical conductivity(EC) of each treatment was controlled by 0.98, 2.25, 5.05 and 9.48 dS/m and $CH_4$ emission was characterized a week interval by closed chamber method during rice cultivation. The $CH_4$ emission rate was significantly decreased with increase of salt accumulation, but total $CH_4$ flux in EC 5.50 dS/m treatment was lower than those of EC 9.48 dS/m treatment. It seems because of higher content of water soluble $SO{_4}^{2-}$ in EC 5.50 dS/m treatment than those of EC 9.48 dS/m treatment. Rice growth and grain yield were significantly decreased with increase of salt accumulation. Soil properties, especially EC and pH were negatively correlated with $CH_4$ flux, while rice growth characteristics like plant height and tiller number show significantly positive correlation with $CH_4$ flux. CONCLUSION(S): Conclusively, salt accumulation significantly decreased $CH_4$ flux in a rice paddy, which could be useful information for evaluating $CH_4$ flux in reclaimed area in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.184-188
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• 2001

This study was conducted to find out the basic informations related to the rice cultivation using the infant seedlings. Infant seedlings with different nursery Periods were compared for the growth and grain yield of rice at the National Crop Experiment Station in 1997. The highest sound seedling ratio of 93.9% was observed in 8-day old seedling, followed by 88.9% of 12-day, 82.0% of 16-day, and 80.8% of 20-day, The endosperm remained 52.5% in the 8-day old seedling at transplanting and decreasingly with increasing nursery period. Missing hills at transplanting were more in 16-day and 20-day old seedling than in 8-day and 12-day old seedlings, 5.1-5.2% in 8-day and 12-day growing seedling, 6.7% in 16-day and 7.8% in 20-day old seedling. Rooting ability was observed highest in 8-day, followed by 12-day, 16-day and 20-day old seedling. The milled rice was lower by 5-16% in 12-day, 16-day and 20-day old seedling than in 8-day old seedling of 6.18 t/ha. It was found that the 8-day and 12-day old seedling provided more advantage for sound seedling ratio, endosperm remaining, missing hill during transplanting, rooting ability and grain yields than 16-day and 20-day old seedlings.

• Journal of Life Science
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• v.25 no.9
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• pp.1036-1042
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• 2015

By using effective sanitizers, early block for transmission of pathogens is the effective way to prevent epidermic outbreaks. Here we developed a chlorine oxide bubbling type of sanitizing tablets and evaluated the disinfectant and sanitization effects. The sanitizers showed 99.999% of sanitization effect for Escherichia coli ATCC 10536 and Staphylococcus aureus ATCC 6538 strains for 5 min±10 sec on 20±1℃ in clean condition by dilution-neutralization method. It reduced more than 5 log₁₀ cfu/ml of a legal permission standard of colony reduction. When a few used socks and underwear soaked for one hour in the 0.1% of the sanitizing tablets, no microorganisms were grown on CHROMagar plates. However, on CHROMagar plates of the no sanitizing tablets treated control, about 6.5×10⁴ cfu/ml of Staphylococcus sp., Klebsiella sp. and Enterococus sp. were grown. Furthermore, the sanitizing tablets killed approximately 1.5x10⁸ cfu/ml of E. coli BL21 in 5 minutes. Therefore, we concluded that the chlorine based bubbling type of sanitizing tablets satisfied the legal standard for the regulation of food and drug safety for disinfectants and sanitizers to pathogens and daily supplies.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.161-165
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• 1997

This experiment were carried out to clarify the effects of several factory wastes on the emergence and seedling growth of five crop species, rice, Chinese cabbage, melon, and tomato. Wastes of three factories treated by several concentrations on the soil in which crop were seeded. In rice seedling experiments, the rice seedlings were treated with factory wastes hydroponically. Factory wastes used in the experiment were obtained from leather, phenol resin, and dye factory. The growth of rice seedlings was inhibited by each factory wastes, but the dry weight of rice seedling was increased by the low concentration below 1/16 dilution of leather factory waste. During 15 days, dry matter accumulation of rice seedlings treated with undiluted factory wastes decreased to 46.0, 51.4, -5.4% of control by treating wastes of phenol resin, leather, and dye factory respectively. The injury of crops by leather factory waste was severe in tomato but slight in barley. Waste of phenol resin factory affects highly both on Chinese cabbage and on melon. When dye factory waste was treated on each crop, all plants died in the treatments of waste solution which diluted to 1/8 of original waste. Tomato and melon were most sensitive crop species to the waste of dye factory. Although the responses of crops to each factory waste were various, the degree of injuries were more higher in vegetables than cereal crops.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.488-494
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• 1993

A photosynthetic bacterium strain P17 having high growth rate and assimilating ability of organic acids was isolated from several soil samples, which was identified as Rhodospirillum rubrum. Cultural conditions of the strain P17 were examined for the production of starter culture used in the treatment of organic waste water. The addition of organic acids mixture as carbon source containing 0.2% Na-acetate, 0.1% Na-propionate and 0.2% Na-lactate and 0.1% of yeast extract as growth factor stimulated the cell growth. The maximal cell production was obtained at $30^{\circ}C$, pH 7.0, 2,500 lux of illumination and $50{\sim}100\;rpm$ of agitation. Under the optimal conditions of batch and fed-batch culture systems in a Jar fermentor, 5.17 g/l and 7.93 g/l of cells were obtained after S days of cultivation, respectively. In continuous culture system, the cell productivity was 0.206 g/l/h at a dilution rate of 0.21 $h^{-1}$. When R. rubrum P17 was cultivated in a soybean curd waste water, initial COD level(3,240 mg/l) of the waste water was reduced to 250 mg/l after 4 days of cultivation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.167-173
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• 1979

It is preented the removable moving screen media-activated sludge (REMSMAS) process by using the biological fixed-film systems. The substrate removal kinetic difference between the aeration-only completed mixing activated sludge (CMAS) process and REMSMAS process were observed. The substrate removal kinetics were developed based on the attached and suspended microbial growths. The units of the aeration-only CMAS process were continously operated with the normal detention time of 4.5, 6, 9.5 and 12 flours studies after steady-state condition and the operating of the REMSMAS units conducted with the normal detention time of 6 and 12 hours studies in nonsteady-state condition. The feed solution was diluted 18 times to the raw starch wastewater in of order to maintain the proper COD (950mg/l) and BOD (450mg/l) concentration. Design parameters related to the suspended microbial growths were caculated by the equations used in the aeration-only CMAS model and these parameters used to evalute the kinetic constants in the REMSMAS process. The kinetic constant values of $Y_2,\;K_d,(\mu_{max})_s\;and\;K_s$ from Monod equations were respectively 0.78, 0.027/hr, 1.1/hr and 95mg/l in the aeration-only CMAS process. The value of the aera capacity (F) appeared to be $9.1\;mg/cm^2-day$ and the mean value of the saturation constant $(K_g)$ appeared to be 53.5 mg/l in the REMSMAs process. Also, the substrate removal .ate of the REMSMAS process was higher than that of the normal activated sludge process when this system was operated in steady-state condition. However, the rate was reduced as the critical operating day was approached.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.1
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• pp.39-45
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• 2005

In the situation which Russia's ratification of the Kyoto protocol at February,2004, ANNEX I nations must reduce GHG(Green House Gas) discharge rate from 2008 by 2012 to the reduction level at 1990. We introduce the CO₂ ocean sequestration that is one of promising method for getting the stable CO₂ concentration in the atmosphere. There are four categories : ocean transportation technique, ocean initial dissolution technique, ocean deep current evaluation technique, and ocean biological evaluation technique. In this paper, we carried out the fundamental numerical study on the ocean initial dissolution technique, when the Liquidized CO₂ is emitted at the deep ocean, It is very important to the dissolution rate of movable CO₂ interface because it Is directly impact to the ocean organism. In order to investigate the relation of the interface movement and rate of the dissolution, we develope CR(Computational Fluid Dynamics) code that was constructed by the finite volume method based on the unstructured mesh, and a droplet's boundary surface can move and one direction dissolution from disperse phase into continuous phase adopted as its physics be. This study clarifies hydrodynamic relation between solubility and movement of the droplet through the verification of the Cm code.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.27-34
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• 2002

The performances of fish culture were evaluated in the integrated recirculating aquaculture system consisting of a double drain type rearing tank ($2.5 m^3$), a sedimentation tank, a floating bead filter, a foam separator and a rotating biological contactor. A system was stocked with nile tilapia at an initial rearing densities of $5\%$ (A), $5\%$ (B) and $7\%$ (C) oyer 30 days. Feed coefficient was 1.62, 1,79 and 1.80 and average daily growth rate was $0.452\%$, 0.u5% and $0.423\%$, respectively. The level of TAN was maintained below $1 g/m^3$ for $5\%$ of initial rearing density and $2-4 g/m^3$ for $7\%$. The dissolved oxygen level ($2-4 g/m^3$) was not optimum but should not be inhibitory to fish growth. The total suspended solid was completely removed during overall experimental period.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.200-205
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• 2011

This study was conducted to find the physico-chemical properties and the amino acid content of the pigs hoof hydrolysate, keratin protein and to investigate its fertilizer effect on the growth of crops. The keratin proteins such as pigs hoof were alkali-hydrolyzed to produce the hydrolysates. The chemical properties of the hydrolysate of pigs hoof was 6~7 of pH and $10{\sim}15dS\;m^{-1}$ of EC. Total amino acid contents released from the pigs hoof were 10.18%, respectively. The pot experiment was carried out for the cultivation of lettuce. The treatment design of these pot cultivation was composed of Control (compost + NPK), PHH-0.5, PHH-1.0, PHH-2.0 (${\times}2,000$ ; 1,000 ; 500 diluted solution of pig hoof hydrolysate). After lettuce cultivation, the pH values in all treatment soils were decreased than those in initial soils, and the exchangeable cation value was higher than that of control. In all PHH treatments, lettuce growth was better in the leaf length by 6~16% and the leaf width by 4~15% than in control. Therefore, the PHH solutions manufactured by hydrolysis process had plenty of amino acids, and among them PHH had the most abundant nutrients and amino acids with highest growth and yield effect on lettuce.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.176-181
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• 2004

Gluconacetobacter hansenii TF-2, an isolate from black tea fungus, was statically cultivated to ferment cellulose gel from citrus juice. The juice prepared by press filtering of peeled citrus fruit contained 135.5 mg of total sugar/mL, 1.23% of total acid, and average pH of the juice was 3.98. The bacterium produced cellulose gel optimally on the surface of culture broth containing 17% of citrus juice and 10$^{\circ}$Brix of total sugar. The optimum temperature was 3$0^{\circ}C$ for producing acetic acid and gel formation. The bacterium could not produce acetic acid on gel formation at 4$0^{\circ}C$. The optimum pH was 3.0∼4.0 but was not significantly different between pH 3.0∼4.0. The cultivation for 18 days under optimal conditions produced gel as 14.2$\pm$0.6 mm of thickness and acids equivalent to 1.90$\pm$0.22% of acetic acid. The pH of culture broth was stabilized at 2.6∼2.8 during the cultivation. Remaining sugar content was 27.1$\pm$4.2 mg/mL of total sugar and 6.9 mg/mL of reducing sugar. The gel productivity was 137.8$\pm$9.7 g/L.