• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.59-61
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• 2005

In Korea, hundreds of abandoned and closed coal and metallic mines are present in the steep mountain valleys due to the depression of the mining industry since the late 1980s. From these mines, enormous amounts of coal waste were dumped on the slopes, which causes sedimentation and acid mine drainage (AMD) to be discharged directly into streams causing detrimental effects on soil and water environments. A limestone slurry by-product (lime cake) is produced from the Solvay process in manufacturing soda ash. It has very fine particles, low hydraulic conductivities ($10^{-8}{\sim}10^{-9}cm/sec$), high pH, high EC due to the presence of CaO, MgO and $CaCl_2$ as major components, and traces of heavy metals. Due to these properties, it has potential to be used as a neutralizer for acid-producing materials. A field plot experiment was used to test the application of lime cake for reclaiming coal wastes. Each plot was 20 x 5 m (L x W) in size on a 56% slope. Treatments included a control (waste only), calcite ($CaCO_3$), and lime cake. The lime requirement (LR) for the coal waste to pH 7.0 was determined and treatments consisted of adding 100%, 50%, and 25% of the LR. The lime cake and calcite were also applied in either a layer between the coal waste and topsoil or mixed into the topsoil and coal waste. Each plot was hydroseeded with grasses and planted with trees. In each plot, surface runoff and subsurface water were collected. The lime cake treatments increased the pH of coal waste from 3.5 to 6, and neutralized the pH of the runoff and leachate of the coal waste from 4.3 to 6.7.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.2
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• pp.68-76
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• 1989

The effect of characteristic of mixture sowing combination on the development of botanical composition was conducted for 12 years on the meadow experiment. The results of this study were summarized as follows. 1. Festuca pratensis lost the expected position of a dominant species. Its vegetation ratio decreased gradually until the last survey year. 2. Arrhenatherum elatius, known as a typical 2-cutting grasss, developed to a dominant species only in the 3- cutting plot without limitation. 3. Alopecurus pratensis, whose feeding value diminishes rapidly, developed to a dominant species regardless of N-fertilization under the condition of 3-cutting, even though the same small amount of seeding was introduced as usual. 4. Trisetum flavescens which causes calcinose exceeded the 40% of vegetation ratio which was the approved rate for feeding at the high N-level (2OOKgIha). 5. Among the introduced, the species showed the significance in quantity were Lotus corniculafus solely in the 2-cutting plot, and Trifolium repens solely in the 3-cutting plot. In the 3-cutting plot legume yet remained under N-fertilization. 6. The appropriate ratio of vegetation for the subordinate species in the mixture sowing combination was easily attained from the least amount of seeding (Gramineae with max. 3Kg/ha, Leguminosae with max. 2kgIha). 7. Into the mixture sowing combination, infiltrated unintroduced species marked more noticeably in the 2- cutting plot than in the 3-cutting plot.

• Analytical Science and Technology
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• v.12 no.3
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• pp.177-183
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• 1999

The determination method of free acid in spent U-Al nuclear fuel solutions by Gran plot titration was described. Effect of U(VI) and Al(III) on the alkalimetric titration of nitric acid was investigated in oxalate complexing media as well as in noncomplexing media. Positive biases were observed in both titration media when the end-point was estimated by the Gran plot method. It was found that the cause of the bias was U(VI) in the oxalate complexing media, but Al(III) in the noncomplexing media. The relative error was less than 1% in the titration of 0.1 M $HNO_3$ at a U(VI) : Al(III) : $H^+$ mole ratio of up to 2:12:1 as long as the pH of the oxalate titration media was sustained to be below 5.0 at the beginning of titration. The method was successfully applied to the determination of nitric acid in a solution of HANARO reactor fuel with U:Al mole ratio of 1:6.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.3
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• pp.1-11
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• 2015

This research was conducted to compare the effect of soil amendment and loess on physial and chemical properties of dredged soil and primary height growth of Ulmus davidiana var. japonica. Three types of research plots: control plot (Dredged soil only), DC treatment plot (Dredged soil + soil amendment) and DCL treatment plot (Dredged soil + soil amendment + Loess) were set at Okgu research site in Saemanguem. 32 trees of U. davidiana var. japonica were planted in each plots after 14 months from the construction. Soil texture, pH, electrical conductivity (EC), organic matter (OM), total nitrogen (TN), available P, exchangeable cation ($K^+$, $Na^+$, $Mg^{2+}$, $Ca^{2+}$) and sodium chloride were measured after 3 years from the construction. Also, survival rate and height of U. davidiana var. japonica were measured 22 months after planting, and the correlation between height of trees and the physico-chemical properties of soil were analyzed. Even though pH in both DC and DCL treatment plots are lower than control plot, they are still alkaline (> pH 8). OM, TN and available P in both DC and DCL treatment were higher than the control. Particularly, the content of available P in both DC and DCL treatment plots are 1.4~5.1 times and 2.0~3.1 times higher than the control respectively. The concentration of exchangeable Mg in DCL treatment plot was 1.1~5.5 times higher than the control (p < .05). The survival rate of the species was the highest in DCL treatment plot (98%) followed by DC treatment plot and the control. The average height of the trees in both DC and DCL treatment plots is 1.1m while the control is 0.8m. OM, TN, available P, K+ were significantly related to the height of U. davidiana var. japonica(p < .01). The results indicate that soil amendment affects on soil physial and chemical properties of dredged soil and height growth of U. davidiana var. japonica.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.4
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• pp.237-242
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• 2000

This study was conducted to investigate the effects of cutting frequency on dry matter yield and nutritive value between heading and headless varieties of sorghumxsudangrass hybrid in 1998. Treatments were var. TE hay grazer(heading type) and Jumbo(headless type) as main plot, and 1, 2, and 3 cutting times per a year as sub plot. Although plant height of sorghumxsudangrass hybrid was no significant difference among treatments, headless type was very slightly higher than that of heading type, and both of variety decreased with 1, 2, and 3 cutting times in order. Also, dry matter yield of sorghum~sudangrass hybrid was no significant difference between heading and headless type. Dry matter yield of first cutting plot in heading type and in headless type was the higher than those of second and third cutting plot. Acid detergent fiber and neutral detergent fiber of headless type were slightly higher than that of heading type. Acid detergent fiber of sorghumxsudangrass hybrid was highest at first cutting plot in both varieties. Neutral detergent fiber of second cutting plot in heading type and first cutting plot in headless type were the highest respectively. In vitro dry matter digestibility of headless type was very slightly higher than that of heading type. And in vitro dry matter digestibility of second cutting plot was the highest in both varieties. In vitro digestible dry matter of sorghumxsudangrass hybrid was no significant difference among treatments. The results demonstrated that although there was not significant difference, cultivation of headless type and first cutting plot per a year were very good for nutritive value and DM yield of sorghumxsudangrass hybrid as summer forage crops in Korea. (Key words : Heading, Headless type, Cutting frequency, Sorghum X Sudangrass Hybrid)

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.96-99
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• 1984

The analysis of data about the 6-year-old Korean pine plantation was done in order to decide the suitable plot size for the survey on several stand characters. The plot size of at least 0.04 ha was recommendable for the investigation of height; but the size of 0.08 ha for D.B.H. and for crown width.

• Journal of Plant Biology
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• v.10 no.1_2
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• pp.36-40
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• 1967

1. The effect of the pH value on P32 absorption of leaves of three forest trees under the water culture is investigated. 2. The degree of the P32 absorption to the pH value is quite different in each forest tree. 3. The phosphorus contents are proved higher in the leaves of Quercus accutissima(the saw shaped oak) than in the leaves of Pinus densiflora(the red pine) and Lespedeza bicolar (bush clover). 4. Larger contents of phosphorus are found in acidity plots than in alkalinity. The leaves of treated plot of the pH 4 (red pine), of the pH 5.0 (bush clover), and of the pH 5.0-6.5 (saw shaped oak) have a higher nutrient capital as indicated by P32 compared with that of the other pH values. 5. It is also noticed that P32 absorption capacity is decreased with the higher pH values. 6. The content of P of leaves shows the lowest value in the plot of the pH 6.5 (pine), of the pH 7.5(bush clover), and of the pH 9.0(saw shaped oak). It is also noticed that the red pine is to do very well in acid cultivation and then follow bush clover and saw shaped oak in the order.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.107-113
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• 1987

A pot experiment was carried out using Seomjinbyeo to investigate the effects of some sulfur-containing substances on the growth of rice plants and on soil characteristics. The results are summarized as follows: 1. Soil pH in plots given the sulfur treatments was lower than that in the urea plot during the growing stages. Soil pH in plots given the mineral sulfur treatments was higher than that in the ammonium sulfate plot at the early growth stage of rice. However, as the stage of rice growth progressed, soil pH became similar. After the experiment, soil pH was higher, but the sulfur content of soil was lower in the urea plot compared with that in other sulfur plots. After the experiment, the sulfur content of soil in the ammonium sulfate plot was the lowest among the plots given the sulfur treatments. 2. Plant heights and the number of tillers of the rice plants in plots given the sulfur treatments were higher than those in the urea plot, specially in the number of tillers of the rice plants. 3. Nitrogen and sulfur contents of the tops of rice plants in plots given the sulfur treatments were slightly higher than those in the urea plot. nitrogen and sulfur contents in the ammonium sulfate plot were higher than those in plots given the mineral sulfur treatments at the early growth stage of rice. However, as the stage of rice growth progressed, those in plots given the mineral sulfur treatments were higher. 4. The chlorophyll content in the leaf blade at heading stage in plots given the gypsume and given the mineral sulfur treatments was significantly higher than that in the urea plot. The N/S ratio was negatively correlated with the chlorophyll content.

• FLOWER RESEARCH JOURNAL
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• v.18 no.4
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• pp.238-243
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• 2010

This study was conducted to investigate effects of nutrient solution pH control agent and foliar spray of ethephon on the reduction of stem inside-cavity and improvement of flower quality in chrysanthemum 'Baekma'. Changes of pH in nutrient solution as affected by the kind of pH control agent showed more settled pattern in the plot of KOH treatment than in others. Plant growth and development such as cut flower length, leaf numbers, cut flower weight and petal number were the greatest in the plot of KOH. However, the size and area of stem cavity was large in KOH rather than $KHCO_3$. As changes in the absorbing patterns of mineral elements as affected by nutrient solution pH control agent in closed system, contents of total nitrate, phosphorus, potassium and calcium by $KHCO_3$ was absorbed into the plant less than KOH, so that it remained a lot of mineral element residues rather than KOH in closed system. Plant growth as affected by the foliar spray of ethephon showed growth retardation effect in the plot of solution diluted to 1 : 500 and growth promotion effect in the plot of solution diluted to 1 : 1,000 or 1 : 2,000. The number of petals was the best in the plot of foliar spray of ethephon solution diluted to 1 : 1,000 before flowering at 45 days showing 331 petals compared to control showing 302 petals. The size and area of stem cavity as affected the foliar spray of ethephon was smaller 1 mm and 7%, respectively, in the plot of solution diluted to 1 : 2,000 before flowering at 30 days than in control. Therefore, treating pH stabilization using KOH after floral initiation stage with the foliar spray of ethephon solution diluted to 1 : 2,000 before flowering at 30 days would help to reduce stem cavity size and improve flower quality in hydroponically grown chrysanthemum 'Baekma'.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.471-476
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• 2014

A kinetic study on aminolysis of 2-chloro-4-nitrophenyl X-substituted-benzoates (2a-k) in 80 mol % $H_2O/_20mol%$ DMSO at $25.0^{\circ}C$ is reported. The Br${\emptyset}$nsted-type plot for the reactions of 2-chloro-4-nitrophenyl benzoate (2g) with a series of cyclic secondary amines curves downward (e.g., ${\beta}_1=0.25$, ${\beta}_2=0.85$ and $pK_a^o=10.3$), which is typical of reactions reported to proceed through a stepwise mechanism with a change in ratedetermining step (RDS). The Hammett plot for the reactions of 2a-k with piperidine consists of two intersecting straight lines, while the corresponding Yukawa-Tsuno plot exhibits an excellent linear correlation with ${\rho}_X=1.15$ and r = 0.59. Thus, it has been concluded that the nonlinear Hammett plot is not due to a change in RDS but is caused by stabilization of substrates through resonance interactions between the electron-donating substituent and the C=O bond. Substrates possessing a substituent at the 2-position of the leaving aryloxide deviate negatively from the curved Br${\emptyset}$nsted-type plot for the reactions of Y-substituted-phenyl benzoates (3a-i), implying that the steric hindrance exerted by the substituent at the 2-position is an important factor which governs the reactivity of Y-substituted-phenyl benzoates.