• Korean Journal of Plant Tissue Culture
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• v.24 no.5
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• pp.305-311
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• 1997

Bacillus thuringiensis, a gram-positive soil bacterium, is characterized by its ability to produce crystalline inclusions during sporulation. The crystal proteins exhibit a highly specific insecticidal activity. An insecticidal crystal protein (ICP), Cry II A, is specifically toxic to both lepidopteran and dipteran insects. In this study, tobacco plants transformed by the cry II A gene have been generated. The Cry II A crystal protein was purified from E. coli JM103 harboring cry II A gene by differential solubility. The activated Cry II A was prepared by tryptic digestion. The purified protoxin (70 kDa) and the activated toxin (50 kDa) were analyzed by SDS-PAGE. To generate the transgenic tobacco having cry II A gene, the cry II A gene was subcloned to a plant expression vector, pSRL2, having two CaMV 35S promoters. The recombinant plasmid was transformed into tobacco (N. tabacum var. Petit Havana SR1) by Agrobacterium-mediated leaf disc transformation. Through the regeneration, six putative transgenic tobacco plants were obtained and three transformants were confirmed by Southern blot analysis. It has been found that one plant had single copy of cry II A gene, another had two copies of the gene, and the third had a truncated gene. After the immunochemical confirmation of cry II A expression in plants, the transgenic tobacco plants will be used to study the genetics of future generation with the insecticidal crystal protein gene cry II A.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.219-228
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• 2010

It has been well known that concrete structures exposed to acid and sulfate environments such as sewer, sewage and wastewater, soil, groundwater, and seawater etc. show significant decrease in their durability due to chemical attack. Such deleterious acid and sulfate attacks lead to expansion and cracking in concrete, and thus, eventually result in damage to concrete matrix by forming expansive hydration products due to the reaction between portland cement hydration products and acid and sulfate ions. Objectives of this experimental research are to investigate the effect of mineral admixtures on the resistance to acid and sulfate attack in concrete and to suggest high-resistance concrete mix against acid and sulfate attack. For this purpose, concretes specimens with three types of cement (ordinary portland cement (OPC), binary blended cement (BBC), and ternary blended cement (TBC) composed of different types and proportions of admixtures) were prepared at water-biner ratios of 32% and 43%. The concrete specimens were immersed in fresh water, 5% sulfuric acid, 10% sodium sulfate, and 10% magnesium sulfate solutions for 28, 56, 91, 182, and 365 days, respectively. To evaluate the resistance to acid and sulfate for concrete specimens, visual appearance changes were observed and compressive strength ratios and mass change ratios were measured. It was observed from the test results that the resistance against sulfuric acid and sodium sulfate solutions of the concretes containing mineral admixtures were much better than that of OPC concrete, but in the case of magnesium sulfate solution the concretes containing mineral admixtures was less resistant than OPC concrete due to formation of magnesium silicate hydrate (M-S-H) which is non-cementitious.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.155-160
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• 2015

BACKGROUND: Objective of this study was to investigate adsorption characteristics of $NH_4-N$ to biochar produced from rice hull in respective to mitigation of greenhouse gases. METHODS AND RESULTS: $NH_4-N$ concentration was analyzed by UV spectrophotometer. For adsorption experiment of $NH_4-N$ to biochar, input amount of biochar was varied from 0.4 to 10 g/L with 30 mg/L $NH_4-N$ solution. Its adsorption characteristic was investigated with application of Langmuir isotherm. Adsorption amount and removal rates of $NH_4-N$ were decreased at 53.9% and increased at 20.2% with 10 g/L compared to 0.4 g/L, respectively. The sorption of $NH_4-N$ to biochar produced from rice hull was fitted well by a Langmuir model. The largest adsorption amount of $NH_4-N$ ($q_m$) and binding strength constant (b) were calculated as 0.4980 mg/g, and 0.0249 L/mg, respectively. It was observed that dimensionless constant ($R_L$) was 0.58. CONCLUSION: It was indicated that biochar produced from rice hull is favorably absorbed $NH_4-N$, because this value lie within 0< $R_L$ <1.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.21-30
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• 2011

The recycled soil that is proceeded from demolition concrete structures was analyzed by the methods of the physical and mechanical tests of soil and TCLP test to use the soil in low landfilling for the construction of an industrial complex. The laboratory test for diffusion of alkali ion in soil mass was analyzed by the methods of XRF and ICP. The fish toxicity test was also conducted to find an environmental influence. The recycled soil through the laboratory test satisfied the engineering property for low landfilling and the criteria of soil contamination. However, the solution which producted by 1:1 ratio of recycled soil and water contained the high pH concentration by alkali ion. The calcium hydroxide solution by CSH cement paste was estimated as the main reason why pH concentration is increased more than 9.0. The high pH concentration in recycled soils causes a toxicity to the livability of fishes. A diffusion area of pH concentration in the ground was analyzed by the Visual Modflow Ver. 2009 program based on geotechnical investigation. The high pH concentration in the recycled soils can be remained as high value due to cement paste in the long term period. Therefore, in the early stage of landfilling work, the mixing with the weathered granite soil is necessary to control the pH concentration.

• Analytical Science and Technology
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• v.35 no.6
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• pp.256-266
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• 2022

It is important to determine the concentration of long-lived radionuclides (e.g., ¹²⁹I) in nuclear waste to ensure safety when handling it. To analyze nuclides in a solid sample (e.g., concrete and soil), it is essential to effectively separate and purify the nuclides of interest in the sample. This study reports the comprehensive efforts made to validate the analytical procedure for ¹²⁹I detection in solid samples, using a high-temperature combustion furnace. ¹²⁹I volatilized from the sample collected in 0.01 M HNO₃ solution with a reducing agent (e.g., NaHSO₃) and was rapidly measured by ICP-MS. Analytical conditions, such as pyrolysis temperature and types of mobile phase gas, catalyst, and trapping solution, were optimized to obtain a high recovery rate of spiked ¹²⁹I. Finally, the optimized method was applied for the simultaneous analysis of other volatile radionuclides, such as ³H and ¹⁴C. The performance test results for the optimized method confirmed that the LSC (for ³H and ¹⁴C) and ICP-MS (for ¹²⁹I) measurements, with the separation of volatile nuclides using a high-temperature combustion furnace, were reliable.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.471-480
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• 1985

Recently several synthetic chemicals inhibiting biosynthesis of gibberellic acids were found to be effective in preventing cereal crops from lodging by reducing culm length. The present study aimed to clarify the extent of practical manipulation of the culm length of the rice crop by changing the endogenous level of gibberellic acids with exogenous application of GA$_3$ or GA biosynthesis inhibitor. Three rice cultivars, 'Jinheung', 'Minehikari' (Japonica) and 'Hangangchal' (semi-dwarf Indica x Japonica) were treated with GA$_3$ (0, 20, 50 and 100 ppm solution) and an anti-gibberellin, paclobutrazol (0, 100, 200 and 300 g ai/ha) at three growth stages (maximum tillering, panicle initiation and meiotic stage), respectively. The application of GA$_3$ (50, 100 ppm) at maximum tillering stage and panicle initiation stage promoted the elongation of the 5th internodes from the top and GA$_3$ applied at meiotic stage promoted remarkably the elongation of the 3rd internodes. Culm was most elongated when GA$_3$ was applied at maximum tillering stage in 'Jinheung', at panicle initiation stage in 'Minehikari' and at meiotic stage in 'Hangangchal'. Paclobutrazol shortened the 4th and 5th internodes from the top when it was applied at maximum tillering stage and panicle initiation stage and the 2nd and 3rd internodes when it was applied at meiotic stage in the three cultivars. The semi-dwarf Indica x Japonica variety responded to a greater extent to the GA$_3$ and to a less extent to the anti-gib berellin than the Japonica varieties. The effect of GA$_3$ and paclobutrazol on the panicle length and the number of spikelets per panicle varied with time and dose of their application as well as with variety.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.2
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• pp.119-126
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• 1979

Rice seeds, suweon 264, were germinated under 5 levels of toxic heavy metals, Cd(0, 0.05, 0.5, 5, 20ppm), Cu(0, 0.05, 0.5, 5, 20, ppm), Cr(0, 0.5, 1, 5, 10ppm), Ni(0, 0.5, 1, 5, 10ppm), Co(0, 0.5, 1, 5, 10ppm), Zn(0, 0.5, 5, 20, 40, ppm), Pb(0, 0.5, 5, 20, 40ppm) and Mn(0, 1, 10, 25, 50, ppm) in culture solution, and then grown with supplying culture solution contained respective concentrations. Germination and growth response to the toxic heavy metals were studied. Results obtained are as follows : 1) The germination injury of rice seeds by excess concentration of toxic heave metal in culture solution occured in Cd and Cu; below 0.05 ppm, Ni; below 0.5 ppm, Mn; below 1.0 ppm, Co and Cr; 0.5-1.0 ppm, and 0.5-5 ppm, Zn and Pb. Thereby, in the order of degrees of the elements toxicity to germination, they were arranged as follows : Cd>Cu>Ni>Co>Cr>Mn>Zn$$\geq_-$$Pb. 2) Toxic heavy metal concentrations in culture solution, which result in decreasing dry weight due to the injury of excess concentration of treated elements, were Cd: below 0.05 ppm, Ni, Cr and Co; below 0.5 ppm, Cu and Zn; 0.5-5 ppm, Pb; 5-20 ppm and Mn; 10-25 ppm. The order was Ni>Cd>Cr>Co>Cu$$\geq_-$$Zn>Pb>Mn. 3) The critical contents of Cd, Ni, Pb, Cu, Zn, Mn, and Co in dry matter, Which result in decreasing dry weight, were considered to be 0.05-15.5, 1.50-25.0, 24.0-28.0, 26.5-62.5, 470-645.0, 231.0-500.0 and below 15.0 ppm, respectively. 4) The contents of Cr, Co, Cd, Pb, Ni, Cu and Zn in dry matter by 0.5 ppm treatment concentration of each heavy metals was trace, 15.0, 17.5, 24.0, 25.0, 84.5 and 470.0 ppm, respectively. Thereby, in the order of each element to uptaked by rice seedlings, they were arranged as follow; Zn>Cu>Ni>Pb>Cd>Co>Cr. 5) The hazardous concentrations of root activity by toxic heavy metals in culture solution were Cd; below 0.05, Cu; 0.05-0.5, Cr; below 0.5, Ni; 0.5-1.0, Co; 0.5-1.0, Zn; above 0.5, Pb; 0.5-5.0 and Mn; 1.0-10.0 ppm. The hazardous degree of root activity by toxic heave metals was in the order of Cd>Cu>Cr>Zn>Ni>Co>Pb>Mn.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.735-742
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• 2006

The objective of this study was to elucidate the tolerance of woody plants to simulated acid rain in relation to mycorrhizal inoculation. Germinating seedlings of Robinia pseudoacacia were planted in 1I pots with autoclaved soil mixture of vermiculite, sand and nursery soil at 1:1:1 ratio. Each pot was inoculated with both crushed root nodules from a wild tree of the same species and commercial arbuscular mycorrhizal inoculum of Glomus intraradices at the time of planting the seedlings. Simulated acid rains at pH 2.6, 3.6, 4.6, and 5.6 were made by mixing sulfuric acid and nitric acid at 3: 1 ratio. Each pot received nutrient solution without N and P, and was also supplied with 180 ml of the one pH level of the acid rains once a week for 50 days. The plants were grown in the green house. At the end of experimental period, plants were harvested to determine contents of chlorophyll, mineral nutrients and net photosynthesis in the tissues, dry weight of the plants, and mycorrhizal infection in the roots. Mycorrhizal infection rate was significantly reduced only at pH 2.6, which meant vitality of G intraradices was inhibited at extremely low pH. Height growth, dry weight production, nodule production and chlorophyll content were increased by mycorrhizal infection in all the pH levels except pH 3.6. Particularly, mycorrhizal inoculation increased root nodule production by 85% in pH 5.6 and 45% in 4.6 treatments. But the stimulatory effect of mycorrhizal inoculation on nodule production was reduced at pH 3.6 and 2.6. Net photosynthesis was increased by mycorrhizal infection in all the pH levels. The phosphorus(P) content in the tissues was increased by 43% in average by mycorrhizal inoculation, which was statistically significant except in pH 2.6. It was concluded that mycorrhizal inoculation of Robinia pseudoacacia would enhance growth and resistance of the plants to acid rain by improving the photosynthesis, phosphorus nutrition, and more nodule production.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.83-89
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• 2010

We investigated the growth of cucumber plants, the uptake and use of mineral nutrients, such as $NO_3$-N, $NH_4$-N, $K^+$, $Ca^{+}^{+}$, $Mg^{+}^{+}$ and $Na^+$, absorbed from media solution, and the synthesis and distribution of soluble sugars under nutrient-deficient condition. Difference in plant growth revealed after 20 days of treatment. Nitrate uptake in nutrient-deficient condition was significantly reduced compared with nutrient-normal treatment, and its distribution was primarily in petioles, stem, roots and less in leaves. In contrast, ammonium content was markedly predominated in fast growing organs, and it was significantly different in growing leaves, expanded leaves, and roots under similar growth conditions. $K^+$, lack by deficient nutrient condition, was found in growing leaves. The $Ca^{+}^{+}$ content did not show significant difference between treatments and a substantial portion of $Ca^{+}^{+}$ remained in petioles. The $Mg^{+}^{+}$ content was significantly higher in the leaves of nutrient-normal condition compared with nutrient-deficient condition while significantly lower in stem and roots. The behavior of $Na^+$ in plant was similar to $K^+$ although its content was relatively little. The highest $CO_2$ assimilation was observed in fully expanded leaves of nutrient-normal condition, which was 1.7 times higher compared with nutrient-deficient condition. The instantaneous water use efficiency (A/E) and the A/gsratio, which is an index of leaf intrinsic water use efficiency for individual leaves, was 1.2 and 1.1 times higher, respectively. The total soluble sugar (TSS) contents were highest in leaves followed by petioles, stems and roots, and in younger leaves. The growing leaves contained about 7,200 mg $kg^{-1}$ of TSS in nutrient-normal condition whereas the TSS contents in nutrient-deficient condition were not significantly different between leaves. The $Mg^{+}^{+}$ and $NH_4$- N were positively correlated with the TSS whereas $NO_3$ - N was negatively correlated.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.2
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• pp.101-107
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• 2005

To investigate the effect of pyroligneous acid liquor (PAL) on the maturity of pig manure compost, PAL was treated to the compost piles. The treatments included applications of 100 and 300 times diluted PAL in addition to the control. The compost piles were stirred in three times at the 1st, 10th, and 25th day of composting. Temperature in the compost pile of control treatment increased from 28 to $60^{\circ}C$ within 10 days and remained nearly at the level until 30th day, then it began to decrease. On the other hand, temperature of the PAL-100 and PAL-300 treatments reached 65 to $70^{\circ}C$ within 8 days and became stabilized until 30th day, then the temperature decreased to about $28^{\circ}C$. However, the temperature of control was stabilized approximately at the 40th day. Initially, the pH of control treatment dropped from 8.2 to slightly above pH 8.0 during 4th day, but that of the PAL-100 treatment declined to 7.8. Among treatments, pH value of PAL-100 treatment was the lowest, which was about 7.3 after becoming stabilization. Also the germination index (GI) was increased at all treatments. The C/N ratio range of PAL-100 treatment was better balanced than others and was at 24.3. Moreover the round paper chromatogram of extracted solution of compost of PAL-100 treatment was the sharpest and clearest among treatments. The GI values of control, PAL-100, and PAL-300 in 60 days of composting were about 108, 120, and 118 in germination test using chinese cabbage, respectively. It can be concluded that the addition of diluted PAL solution is effective in composting of pig manure.