• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.3
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• pp.159-168
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• 2005

This experiment was carried out during the period from May to October 1998 to determine the effect of fermented sawdust swine manure application (SSM) on the herbage production of Japanese millet and soil properties in the Cheju brown volcanic ash soil. The randomized block design (T1 : basic chemical fertilizer, N 200 kg/ha + $P_2O_5\;300 kg/ha+K_2O$ 200kg/ha ; T2 : 1/2 basic chemical fertilizer, N $100+P_2O_5\;150+K_2O$ 100kg/ha; T3 : 1/2 basic SSM, N 100kg/ha, T4:basic SSM, N 200kg/ha; T5:2 times basic SSM, N 400 kg/ha ; T6:4 times basic SSM, N 800 kg/ha) was used. At the same application level of nitrogen 200kg/ha, the application of $100\%$ chemical fertilizer (T1) had significantly lower dry matter yield than that of $50\%$ chemical fertilizer and $50\%$ SSM (T2) or $100\%$ SSM (T4)(p<0.01). Dry matter yield increased with an increase of SSM application to N 400kg/ha level but decreased at N 800 kg/ha level. P, K and Ca contents of Japanese millet tended towards to decrease with an increase of SSM level. The application of chemical fertilizer lowered P and K content of Japanese millet in comparison with that of SSM (p<0.05). pH, available phosphorus. exchangeable potassium, Ca and Mg content of soil studied showed a significant increase with an increase of SSM application level (p<0.05). However, at the same application level of N 200kg/ha, there was statistically no significant difference between chemical fertilizer and SSM in those contents of soil after experiment. The bacterial number of soil among microbial population increased with an increase of SSM level, in June, 1998 (p<0.05), but there was no regular tendency, in October. The rate of bacteria to fungus in soil had a tendency to decrease with an increase of SSM level. In conclusion, it is recommended to use N 400kg/ha of SSM or N 100 kg/ha of chemical fertilizer+N 100 kg/ha of SSM for Japanese millet.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.4
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• pp.211-217
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• 1978

Laboratory experiment was conducted to investigate the changes in the amount of inorganic phosphorus forms in soils incubated by preaddition of two kinds of phosphorus fertilizer and to various methods of available soil P. The results are summarized as following. 1. The content of Al-P form was higher in cultivated upland soil than in noncultivated soil and that of Fe-P was higher in clayey soil than in sandy soil. 2. The amount of Al-P was increased greatly by addition of Triple superphosphate and Al-P and Ca-P were increased by addition of Fused phosphate but only a little amount of Fe-P was increased by both two fertilizers. 3. The magnitute of available soil P values of different methods was in order of Bray No. 2-P>Lancaster-P${\fallingdotseq}$Bray No. 1-P>Truog-P>Olsen-P in case of addition of Triple superphosphate, while it was Lancaster-P >Bray No. 2-P>Truog-P>Bray No.1-P>Olsen-P in case of addition of Fused phosphate. 4. Extractability of soil P by variouse extractants for determining avaliable soil p was in order of Al-P>Ca-P>Fe-P but the extractability of Fe-P by Bray No. 1 and Bray No. 2 methods was very slight. 5. Bray No. 1, Bray No. 2 and extractants was more Olsen extractable about Al-P in soil than Ca-P but Lancaster and Truog metho is was more extractable about Ca-P than Al-P.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.1
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• pp.13-22
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• 2003

This pot experiment was conducted to find out the forage productivity and mineral contents in an orchardgrass sward affected by the compost, lime, and phosphorus applications on the newly reclaimed and arable pasture soils. This 3rd part was concerned with the effect of phosphorus application($P_{0}$ : control, $P_1$=1.25ｇ, $P_2$=2.50g, $P_3$=3.75g $P_2$$O_{5}$ pot). The results obtained are summarized as fellows; There were considerable differences between the newly reclaimed and arable pasture soils in the soil chemical characteristics as follows in general; poor~common in the newly reclaimed soil and common~good in the arable pasture soil in terms of soil fertility standard. Comparing with the arable pasture soil, the contents of available$ P_2$$O_{5}$ / in the newly reclaimed soil at end of experiment were considerably increased by the $P_2$$O_{5}$ applications, These effects in the newly reclaimed soil were positively influenced by the additional application of compost, but were adversely influenced by the additional application of lime. The seedling vigour and yield of orchardgrass were far better in the arable pasture soil than in the newly reclaimed soil. At the $P_{0}$ treatment, those were very poor in 也e newly reclaimed soil, but were good in the arable pasture soil. Comparing with $P_1$ treatment, the above effects of heavy $P_2$$O_{5}$ / applications($P_2$and $P_3$) were not recognized. On the newly reclaimed soil, the above effects were markedly enhanced by the applications of $P_2$$O_{5}$ with compost. The Ca, Mg, and P contents of orchardgrass were relatively higher on the arable pasture soil than on the newly reclaimed soil, whereas ere were no differences in the K contents.

• Transactions on Electrical and Electronic Materials
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• v.12 no.3
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• pp.123-126
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• 2011

Titanium dioxide ($TiO_2$) thin films were deposited by the sol-gel method with a surfactant-assisted mechanism. Its application for dye-sensitized solar cells (DSSCs) was investigated. Brunauer-Emmett-Teller, X-ray diffraction and field emission scanning electron microscopy techniques were used to characterize the surface characteristics of thin films. Photovoltaic-current density measurements were performed to determine the photoelectrochemical properties of the thin films and the performance of DSSCs. Energy conversion efficiency of about 6.1% was achieved for cells with conductive glass under illumination with AM 1.5 (100 $mWcm^{-2}$) simulated sunlight. Investigation showed higher photo-energy conversion efficiency for mesoporous $TiO_2$ nanocrystalline films used in DSSCs relative to commercially available Degussa P25 films.

• Journal of the Korean institute of surface engineering
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• v.5 no.3
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• pp.77-85
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• 1972

A method of preparation of synthetic ignorgaic coating on copper (patina) has been presented . An Eh--pH diagram was constructed for the present Cu-H2O-SO$_4$ system using the most recently available thermodynamic data. In the path of the patination at room temperature the general behaviour of copper in acidic copper sulfate solutions with potassium chlorate as an oxidizing agent appeared to follow those predictable in this Eh-pH diagram. In the presence 0.05 molar cupric sulfate at a temperature of about 28$^{\circ}C$ a green brochantite (CuSO$_4$$.$3Cu(OH)$_2$) layer was formed on copper sheet in 20 days. In a solution having an initial pH of 3.5 the development of a brochantite coating has been observed to take place in two stages. In the first, a layer of cuprous oxide formed on the copper at a relatively rapid rate. In the ensuing step the outer layer of cuptrite was oxidized at much slower rate to form brochantite. The syntetic coatings appeared to consist of crystal-lites of brochanitite growing perpendicular to the cuprose oxide surface. The outer tips of the -crystallites were reasily broken off and gave to the layer a rather chalky character. Underneath, at the brochantite Cu$_2$O interface, however, the green layers were firmely attached. The effect of reagent concentration , solution agitation , and moderate temperature increase were investigated to improve the quality of coating. So also in a qualitative way were the effect of light.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.3
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• pp.19-29
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• 2001

This study was carried out to examine the recovery of forest ecosystem at the burned areas of coniferous (Mt. Chosdae) and broad leaved forest (Samsinbong in Mt. Chiri) by investigating the changes of forest vegetation. The results obtained are summarized as follows; 1. In the Samsinbong, the total number of species appeared at the burned area were 5 species at tree layer, 11 species at sub-tree layer and 24 species at herb layer, and at the unburned area were 5 species at tree layer, 14 species at sub-tree layer, 18 species at shrub layer and 23 species at herb layer, respectively. In the Mt. Chosdae, the total number of species appeared at the burned area only showed to 83 species at herb layer, and at the unburned area were 7 species at tree layer, 13 species at sub-tree layer, 21 species at shrub layer and 46 species at herb layer, respectively. 2. In the soil chemical properties of the burned area of Samsinbong, pH was 5.8, and contents of Organic matter, Total nitrogen, Available $P_2O_5$, Exchangeable $K^+$, Exchange $Ca^{{+}{+}}$ and Exchange $Mg^{{+}{+}}$ were 7.42%, 0.73%, 28.5mg/kg, 1.3me/100g, 13.3me/100g and 2.2me/100g, respectively. But they showed a tendency to decrease by passing the time. In the soil chemical properties of the burned area of Mt. Chosdae, pH was 5.3, and contents of Organic matter, Total nitrogen, Available $P_2O_5$, Exchangeable $K^+$, Exchange $Ca^{{+}{+}}$ and Exchange $Mg^{{+}{+}}$ were 6.42%, 0.25%, 24.4mg/kg, 0.7me/100g, 3.7me/100g and 2.1me/100g, respectively, and they also showed a tendency to decrease by passing the time. 3. An the burned and unburned areas of Samsinbong, the total evolved amounts of soil respiration were $4,049.1mg/m^2/h$ and $9,950.0mg/m^2/h$, respectively. An the burned and unburned areas of Mt. Chosdae, the total evolved amounts of soil respiration were $4,392.4mg/m^2/h$ and $8,286.5mg/m^2/h$, respectively.

• Journal of Environmental Science International
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• v.13 no.9
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• pp.807-817
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• 2004

The modified biochemical oxygen demand (MBOD) were conducted to evaluate the water quality and fertility in the Mangyeong river from november 2002 to april 2003. MBOD method was used to evaluate algal growth potentials and their limiting factors. MBOD depends on the amount of available inorganic nutrient and organic substrate during 5-day incubation in the dark condition at $20^{\circ}C.$ The MBOD assay depends on inorganic nutrients such as phosphorus and nitrogen as well as reduced carbon as called MBOD, MBOD-P, and MBOD-N, respectively. The concentration of pollutants were in the range of 3.08～48.36 mg/L for COD. The concentration of nutrients were in the range of 0.37～111.62 mg/L for dissolved inorganic nitrogen (DIN) and 0.00～1.03 mg/L for dissolved inorganic phosphorus (DIP). The results of MBOD bioassay showed that the MBOD, MBOD-P and MBOD-N values were 15～173 mg $O_2/L,$ 13～165 mg $O_2/L$ and 66～175 mg $O_2/L$ ranges, respectively. The MBOD values are found to be the highest in Iksan River and the lowest in Hari River throughout the Mangyeong River. The relationships of MBOD, MBOD-P and MBOD-N in MBOD method were generally found in MBOD$\risingdotseq$ MBOD-P$\risingdotseq$MBOD-N. But the result of Gosan was appeared to MBOD$\risingdotseq$MBOD-N > MBOD-P. The MBOD-N value was higher 3 to 5 times than the MBOD-P value in the Gosan station. The algal growth potentials expressed as the concentration of chlorophyll-a were maximum 20 times more than algal biomass in the water column.

• Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.158-168
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• 2023

The global output of Pyropia yezoensis (dried seaweed or laver, also called 'Gim' in Korea) has been reduced over the half-decade due to the wide spread of red rot disease, a serious algal disease affecting P. yezoensis. Recently, Gold 1 (G1), which is a resistant strain of P. yezoensis to red rot disease, was developed and commercialized in South Korea, yet its physiological activity has not been investigated. In this study, a comparative study was performed on G1 and commercially available strain of P. yezoensis (CP) for their antioxidative activities. Aqueous extract of G1 showed more marked 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity compared to that of CP. In 293T cells, antioxidant activity against H₂O₂-induced reactive oxygen species (ROS) formation was only observed in G1 extract. In addition, G1 extract showed more potent inhibitory effect on H₂O₂-induced apoptotic cell death than CP extract, as examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and fluorescence microscopy. Expression levels of various apoptosis-related genes, including B-cell lymphoma 2-associated X protein, p53, capase-3, and inflammatory cytokines, in H₂O₂-treated cells were significantly decreased by the treatment of G1. Taken together, the present study suggests that a new strain of red seaweed G1 can recover oxidative stress effectively by improving the imbalance of ROS generation and has a potential to be used a functional ingredient as an antioxidant source.

• Environmental Engineering Research
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• v.17 no.4
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• pp.185-190
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• 2012

Rejection characteristics of perchlorate ($ClO_4^-$) were examined for commercially available reverse osmosis (RO) and nanofiltration (NF) membranes. A bench-scale dead-end stirred-cell filtration system was employed to determine the toxic ion rejection and the membrane flux. Model water solutions were used to prepare $ClO_4^-$ solutions (approximately, $1,000{\mu}g/L$) in the presence of background salts (NaCl, $Na_2SO_4$, and $CaCl_2$) at various pH values (3.5, 7, and 9.5) and solution ionic strengths (0.001, 0.01, and 0.01 M NaCl) in the presence of natural organic matter (NOM). Rejection by the membranes increased with increasing solution pH owing to increasingly negative membrane charge. In addition, the rejection of the target ion by the membranes increased with increasing solution ionic strength. The rejection of $ClO_4^-$ was consistently higher for the RO membrane than for the NF membrane and $ClO_4^-$ rejection followed the order $CaCl_2$ < NaCl < $Na_2SO_4$ at conditions of constant pH and ionic strength for both the RO and NF membranes. The possible influence of NOM on $ClO_4^-$ rejection by the membranes was also explored.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.200-206
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• 1985

This field experiment was undertaken to assess the effects of three levels of inclination ($10^{\circ},\;20^{\circ},\;and\;30^{\circ}$) and four rates of $N-P_2O_5-K_2O$ (0-0-0-, 14-10-10, 28-25-25, and 42-40-40kg/10a) on establishment, yield and quality, and botanical compositions of mixed grass-clover sward. This second part is concerned with the soil chemical properties, concentrations and uptake of mineral nutrients, and percent recovery and efficiency of NPK. The results obtained after a two-year experiment are summarized as follows: 1. The pH, exchangeable Mg and Na, and base saturation in the surface soils were decreased by increasing the grade of inclination, whereas organic matter and available $P_2O_5$ tended to be increased. However, the changes in the Ca content and equivalent ratio of $K\sqrt{Ca+Mg}$ were not significant. The pH, exchangeable Ca and Mg, and base saturation were reduced by increasing the NPK rate, whereas available $P_2O_5$, exchangeable K, and equivalent ratio of $K\sqrt{Ca+Mg}$ tended to be increased. 2. The concentrations of mineral nutrients in grasses and weeds were not significantly affected by increasing the grade of slope in hilly pasture, whereas the concentrations of N, K, and Mg in legume were the lowest with the steep slope, which seemed to be related to the low legume yield. The Mg concentrations of all forage species were below the critical level for good forage growth and likelihood of grass tetany. 3. The increase of NPK rate resulted in the increment of N, K and Na concentrations, and the decrease of Mg and Ca in grasses. The P concentration was increased with P application, but there were no differences in that among the P rates applied. It resulted also in a slight increase of K, and a decrease of Mg in legume, but the contents of N, Ca, and Na were not affected by that. On the other hand, it has not affected the mineral contents in weeds except a somewhat increase of N. The mixed forages showed a increase of N and K contents, a decrease of Ca and Mg, and a slight change in P and Na. 4. The percent recovery of N, P and K by mixed forages were greatly decreased by increasing the grade of inclination and NPK rate. They were high in the order; K>N>P. The efficiency of mixed NPK applications was decreased by that. The efficiency of mixed NPK fertilizers absorbed was slightly decreased by the increased rate of NPK, but it was not affected by the grade of inclination.