• Korean Journal of Soil Science and Fertilizer
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• v.30 no.3
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• pp.272-279
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• 1997

Chemical properties of soils and mineral contents in plants grown at seventy one regions located in southern part of Korea were surveyed to obtain the basic information for sustainable management of plastic film house soils. The averaged soil chemical properties showed optimum levels in pH, organic matter, available boron, manganese, zinc contents, whereas available phosphate and exchangeable rations were highly accumulated. Available phosphate showed highly positive correlation with continuous cropping period. The contents of phosphate, potassium, calcium, and magnesium in the top soils were ranged from 912(Pusan)~1.796mg (Masan) ; $1.52(Pusan){\sim}2.93cmol^+$(Sunchon) ; $7.44(Masan){\sim}18.58cmol^+$(Changweon) ; $2.82(Changnyong){\sim}6.24cmol^+/kg$(Changweon), respectively. There were high levels of phosphorus and potassium in the leaves of plastic film house plants of pepper, cucumber, pimento, chrysanthemum, and carnation. And calcium and magnesium were more than two fold high in fruiting vegetables than flowering plants showing antagonistic utilization against potassium.

• Journal of Korean Society of Water and Wastewater
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• v.38 no.1
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• pp.17-27
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• 2024

This paper aims to study the degradation process for refractory azo dye namely Reactive Black 5(RB5) by potassium ferrate(VI) synthesized using the wet oxidation method. The process of degradation of azo dyes by Ferrate was studied with several parameters such as pH, different Ferrate(VI) dosage, different azo dye initial concentration, and temperature. A second-order reaction was observed in all degradation processes for RB5 having the highest degradation efficiency. The highest k_app value of RB5 degradation was 190.49 M^-1s^-1. In the pH experiments, the neutral condition has been identified as the optimum condition for the degradation of RB5 with 63.2% of dye removal. The efficiency of degradation also depends on the amount of ferrate(VI) available in the reactor. Degradation efficiency increased with an increase in Potassium Ferrate(VI) dosage or a decrease of RB5 initial concentration. The temperature has been reported as one of the most important parameters. From the results, increasing the temperature(up to 45℃) will increase the degradation efficiency of azo dye by Ferrate(VI) and if the temperature exceeds 45℃, the degradation efficiency will be decreased.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.5
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• pp.37-48
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• 2015

Soil nutrient management is important to maintain the constant productivity of seedling production in the nursery for successful forest restoration. This study investigated the effects of organic manure and chemical fertilizer application levels on the growth, soil properties, and nutrient concentrations of yellow poplar seedlings. One-year-old yellow poplar seedlings were treated with the combination of 3 level organic manures(0, 5 Mg/ha, 10 Mg/ha; mixture of poultry manure, cattle manure, swine manure, and sawdust) and 3 level nitrogen-phosphorus-potassium(NPK) chemical fertilizers(0, 1x(urea, $30g/m^2$; fused superphosphate, $70g/m^2$; potassium chloride, $15g/m^2$), 2x). Organic manure significantly increased the soil pH and the concentrations of nitrogen, available phosphorous, exchangeable potassium, calcium, and magnesium. In contrast, the NPK chemical fertilizer decreased the soil pH and exchangeable calcium concentration, did not affect the soil concentrations of nitrogen and magnesium, and increased the concentrations of available phosphorous and exchangeable potassium. Both organic manure and NPK chemical fertilizer treatments increased the seedling height, root collar diameter, and dry weight by 39% and 25%, respectively. The treatment with manure 5 Mg/ha and NPK 2x chemical fertilizer mostly increased seedling dry weight by 2.6 times more than that of the control. Compared to the effects of the fertilization treatments on the soil properties, the effects on nutrient concentrations in the leaves were relatively small. These findings indicate that organic manure that was derived from livestock byproducts and sawdust can be utilized with chemical fertilizer to improve seedling production as well as conserving soil quality.

• Korean Journal of Environmental Agriculture
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• v.41 no.3
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• pp.158-166
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• 2022

BACKGROUND: Kiwifruit is a fruit tree with relatively small cultivation area in Korea and researches on its soil and physiology are very limited compared to those on cultivar development. Therefore, there are limited information for farmers to cope with the reduction in productivity due to various physiological disorders and premature aging. This study was conducted to investigate the soil and leaf chemical properties, and fruit characteristics, which will be used as basic data for stable kiwifruit orchard soil management. METHODS AND RESULTS: The soil and leaf chemical properties, and fruit characteristics were investigated for two years in 16 kiwifruit orchards growing 'Hayward' (Actinidia deliciosa) in Jeollanam-do and Gyeongsangnam-do. Soil and leaf samples were collected in July and fruit quality was investigated by harvesting fruits about 170 days after full bloom. The average soil chemical properties of kiwi orchards were generally higher than the recommended level, except for pH, and especially, the exchangeable potassium reached about 300% of the recommended level. The proportions of orchards that exceeded the recommended level of soil chemical properties were 63, 31, 100, 69, 94, 88 and 69% for pH, EC, organic content, available phosphate, and exchangeable potassium, calcium and magnesium, respectively. Thirty-three percent of orchards had more than 100 mg/kg of nitrate nitrogen in soil. Available phosphate in soil showed a significantly positive correlation with leaf nitrogen, phosphoric acid and calcium content, but showed a significantly negative correlation with leaf potassium content. The magnesium content in the leaves was significantly correlated with soil pH. The highest fruit weight was observed in about 25 g/kg of leaf nitrogen content which could be attained when plants were grown on the soil containing about 100 mg/kg of nitrate nitrogen content. The average soluble solids content among 16 orchards was 9.58 °Brix at harvest and 13.9 °Brix after ripening, which increased about 45%, and the average fruit weight was about 110 g. CONCLUSION(S): For fruit quality, fruit soluble solids (sugar compounds) content was significantly correlated with leaf potassium content, fruit hardiness with leaf total nitrate, calcium and magnesium, and fruit titratable acidity with leaf magnesium; however, leaf calcium and magnesium negatively affect the soluble solids contents in fruits.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.246-252
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• 1998

A survey was conducted to investigate the status of soils involving pH, electrical conductivity, total organic matter content, available phosphate and major exchangeable cations in the paddy soils sampled from 1,168 sites throughout the country. The content of soil chemical properties was lower on the average than the optimum levels for cropping. An average value showed pH 5.6, organic matter $25g\;kg^{-1}$, available phosphate $128mg\;kg^{-1}$, available silicate $72mg\;kg^{-1}$, and exchangeable potassium and the calcium and magnesium were 0.32, 4.0, $1.2cmol^+\;kg^{-1}$, respectively. Soil chemical properties was related with topography except soil pH. A soil pH and organic matter, available phosphate, exchangeable potassium increased with time while exchangeable calcium, magnesium available silicate decreased with time.

• Food Science and Preservation
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• v.25 no.1
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• pp.19-26
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• 2018

In this study, we aimed to increase the utilization of non-commercializable peach fruits collected during harvesting and distribution and to promote the transition of a high value-added industry. After producing pastes from the flesh of different peach varieties, we used these pastes as ingredients in the production of Kochujang. We then performed a comparative analysis on the quality characteristics of the peach-added Kochujang and commercially available Kochujang products. Peach-added Kochujang exhibited a lower pH and reduced sugar, salinity, reducing sugar, ash, and calorie content than those of commercially available Kochujang products. However, the Kochujang had slightly higher pH and moisture content than commercially available products due to high organic acid and moisture contents of peach flesh. In terms of content of inorganic elements, commercial Kochujang products exhibited higher sodium and magnesium content, whereas peach-added Kochujang had higher potassium content. In particular, the lower sodium and higher potassium content of peach-added Kochujang indicates that this product could be used as a functional food to prevent various diseases caused by excessive sodium intake among Koreans. After comparing the products in terms of phenol and flavonoid content, we concluded that ethanol extracts of peach-added Kochujang showed higher phenol content than those of the commercially available Kochujang products. In contrast, the distilled water extracts of peach Kochujang showed higher DPPH free radical scavenging activity than that of commercially available Kochujang products.

• Journal of the Korean Graphic Arts Communication Society
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• v.14 no.2
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• pp.37-49
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• 1996

The practical lith developer is a hydroquinone solution of moderate alkalinity and low free-sulfite ion concentration with potassium bromide as the restraining agent. In the study on composition of ilth developer to promote high sensitivity, high contrast and long term preservation or use, a new composition of lith developer, namely PK lith developer, was developed and of was found that PK lith developer was superior to the lith developer which was commercially available in terms of contrast, speed and preservation. This paper also describes studies on the addition of hdydrazine to PK lith developer, which have led to further improvements in the system.

• The Korean Journal of Ecology
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• v.17 no.4
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• pp.425-434
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• 1994

After two highly weathered soils were treated with glucose, ammonium nitrate, monobasic potassium phosphate and biocides, and incubated for 4 or 6 weeks, adsorption tests were carried out to determine their effect on P adsorption. Glucose addition generally decreased P adsorption. The addition stimulated microbial activity, which might contribure to the reduced adsorption, probably through chelation and anion competition. Consistent endency was not observed with N treatment. Addition of P initially decreased P adsorption, probably through blockage of adsorption sites. Biocides generally decreased adsorption, probably because the microbes that 몬 been killed. Soil 1 with naturally lower levels of C and higher levels of aluminium adsorbed more P than soil 2. These results suggest that in highly weathered soils, which are low in available P and high in exchangeable Al, cultivation techniques which increase soil organic matter will also result in higher levels of plant-available P.

• Computers and Concrete
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• v.13 no.2
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• pp.149-171
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• 2014

This study presents the mathematical model for predicting chloride penetration into saturated concrete under non-isothermal condition. The model considers not only diffusion mechanism but also migration process of chloride ions and other chemical species in concrete pore solution such as sodium, potassium, and hydroxyl ions. The coupled multi-ionic transport in concrete is described by the Nernst-Planck equation associated with electro-neutrality condition. The coupling parameter taken into account the effect of temperature on ion diffusion obtained from available test data is proposed and explicitly incorporated in the governing equations. The coupled transport equations are solved using the finite element method. The numerical results are validated with available experimental data and the comparison shows a good agreement.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.235-242
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• 2015

The objective of this study was to determine the effects of soluble potassium silicate by soil drenching application on watermelon growth, yield, and nutrient uptake. The potassium silicate rates were control (No potassium silicate), 1.63mM, 3.25mM, 6.50mM. The potassium silicate were treated 6 times (twice before fruit forming and 4 times after fruit forming per 7 day. Soil chemical properties, such as soil pH, EC, available phosphorus and silicate, exchangeable K, nitrate-N levels were increased after potassium silicate treatment, while the concentrations of soil organic matter, exchangeable Ca and Mg were similar to control. The growth characteristics of watermelon, such as stem diameter, fresh and dry weight of watermelon at harvest were thicker and heavier for increased potassium silicate treatment than the control, while number of node, and plant length were same for all treatments. With increased potassium silicate treatment, nutrient concentrations, such as P and K in the watermelon leaf at harvest were increased, N concentration in the leaf was decreased, and Ca and Mg concentrations in the leaf were same. Chlorophyll content was increased with increased potassium silicate application. The occurrence of powdery mildew was lower for the potassium silicate treatments than the control. Fresh watermelon weight for the potassium silicate treatments was 0.1 to 0.5kg per watermelon heavier than the control, sugar content was 0.5 to $0.6^{\circ}Brix$ higher than control, and merchantable watermelon was 2 to 4% increased compared to the control. These results suggest that potassium silicate application by soil drenching method in the greenhouse can improve watermelon nutrient uptake, merchantable watermelon and suppress the occurrence of powdery mildew.