• Journal of the Korean Society of Groundwater Environment
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• v.7 no.3
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• pp.116-124
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• 2000

Geochemical and isotopic analyses were carried out to investigate hydrochemical characteristics, source of carbon species in the carbonated waters in South Korea. Most Korean carbonated waters from different geologic settings are characterized by a Ca-HCO$_3$type with a relatively low pH range from 5.3 to 6.3 (avg. 6.0). The concentrations of cations and anions in the carbonate waters are in the order of Ca$^{2＋}$>Na$^{＋}$>Mg$^{2＋}$>Si$^{4＋}$>Fe$^{2＋}$>K$^{＋}$ and HCO$_3$$^{－}$>SO$_4$$^{2－}$>Cl$^{－}$, respectively. The HCO$_3$$^{－}$ ion is more enriched in the carbonated water from the sedimentary rock and granitic rock of Mesozoic age in the Gyungsang basin(GII) and the Precambrian metamorphic rock and Jurassic granitic rocks of the Gyunggj massif in the Gangwon province(GⅠ) than those of the meta-sedimentary rock and granite in the Ogcheon zone(GⅢ). Based on the oxygen and hydrogen isotopic data, the carbonated waters are derived from the meteoric water, showing apparent latitude and altitude effects. The $delta$$^{13}$C values of carbon species in the carbonated water are in between -6.23 and 0.0 $textperthousand$, suggesting inorganic source of carbon originated from the carbonate mineral and carbonate rock in the aquifer.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.549-555
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• 2010

Here we focused on tip-burn and blossom-end rot (BER) symptoms in the tomato plants expressing the constitutively active form of $Ca^{2+}/H^+$ antiporter (sCAX1) and/or a Ca-binding protein (calreticulin, CRT) genes during their whole growth period. Conclusively we demonstrated that CRT is able to suppress the tip-burn and BER symptoms that were induced by sCAX1. Under poor nutrition condition, tomato plants overexpressing sCAX1 showed severe necrotic collapses in both roots and shoot polar tissues, which are in accordance with $Ca^{2+}$ deficient symptoms frequently observed in an agricultural cultivation of tomato. Reciprocal grafting trials using sCAX1 and wild type plants revealed that the tip-burn symptom by sCAX1 overexpression is not caused by hindrance of $Ca^{2+}$ uptake from soil. We constructed CRT overexpressing transgenic tomatoes, and crossed them with sCAX1 transgenic plants to investigate the effects of CRT on the symptoms of sCAX1 transgenic plants. Co-expression of sCAX1 and CRT significantly suppressed the $Ca^{2+}$ deficient symptoms of sCAX1 transgenic plants. Those results suggest the model that $Ca^{2+}$ homeostasis disturbed by the overexpression of sCAX1 may be suppressed by the co-expression of CRT.

• Journal of Life Science
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• v.12 no.1
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• pp.77-86
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• 2002

Chitin, a $\beta$-1,4 polymer of N-acetyl-D-glucosamine, is one of the most abundant organic compounds in nature. Chitinase (EC 3.2.1.14) is an enzyme that degrades chitin to chito-oligosaccharides, diacetyl rhitobiose and N-acetyl-D-glucosamine. An extracellular chitinase-producing bacterial strain was isolated from soil and named to as Bacillus subtilis JK-56. Optimum culture condition of B. subtilis JK-56 for the production of chitinase was 1% chitin, 0.5% polypepton, 0.1% KCl, 0.05% MnS $O_4$.4$H_2O$, 37$^{\circ}C$, initial pH 7.0 and 40 hour culture time. When B. subtilis JK-56 was grown in the optimum medium, one major active band and two minor active bands were detected by native-PAGE and active staining of the gel. Among them, the major band was purified from the culture supernatant by 70% ammonium sulfate precipitation and native-PAGE with BIO-RAD Model 491 Prep-Cell and named as Chi-56A. Its molecular weight was estimated to be 53kDa monomer and the isoelectric point (pI) was pH 4.3. The pH and temperature for the optimum activity of Chi-56A were pH 6.0 and $65^{\circ}C$, respectively. Chi-56A was stable up to $65^{\circ}C$ and in alkaline region. Its $K_{m}$ value for colloidal chitin was 17.33g/L. HPLC analysis of the reaction products confirmed that Chi-56A was an exo type chitinase.e.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.3
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• pp.277-291
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• 2020

Shield TBM is a tunnelling method that has a wider range of applications in the poor ground condition compared to conventional tunnels (Drill and Blast). Currently, a 13.3 m large-diameter slurry shield TBM is preparing for construction to pass under the Han River. Shield TBM is divided into slurry and EPB shield TBM, and management items during construction are different depending on each characteristic. In this paper, the equipment type, origin, application case and trouble case were analyzed for slurry shield TBM, which is mainly constructed in soft ground. In addition, 2D and 3D model tests were conducted on the condition of soil depth for the possibility of slurry leakage into front of the equipment, with appropriate chamber pressure. Based on this paper, it proposed to provide basic and reference data for proper excavation surface pressure and chamber pressure during construction of slurry shield TBM under soft ground conditions, and proposed measures to minimize stability and environmental decline due to slurry ejection.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.73-80
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• 2011

This study was conducted to elucidate the best cutting condition in propagation of Juniperus chinensis var. sargentii in respect of survival rate, rooting rate, and early growth after cutting via process of cutting time, cutting media, cutting type and growth regulators. As for cutting time, rooting rate was 68.3% on April, which was higher than 39.5% on May and 32.5% on June. The best cutting media was stream sand of rooting rate 72.7%. Those of mixed soil and decomposition were 40.1% and 27.5% each. The effect of growth regulators was different according to the kind of cutting media. There was no effect on stream sand media which showed the highest rooting rate, while it was very effective on the media of decomposition of granite, which rooting rate showed the lowest. Hardwood as cutting materials showed somewhat higher survival and rooting rate compared to semi-hardwood. The cutting with hardwood condition to stream sand on April, it is regarded to be the most effective condition for Juniperus chinensis var. sargentii to increase survival and rooting rate. Therefore in this experiment it is considered that the best season cutting is April, and the most useful media and plant materials stream sand, and hardwood respectively.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.222-227
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• 2008

Objective of this Research was to determine the influence of foliar application of $CaCl_2$ or $K_2SI_2O_5$ and soil application of $CaCO_3$ or $SiO_2$ on growth and cut flower quality of Zantedeschia aethiopica 'Wedding March'. To achieve this, $CaCl_2$ or $K_2SI_2O_5$ were applied at six leaf stage with the concentration of 0.05, 0.1 and 0.2% and $CaCO_3$ or $SiO_2$ were applied as basal fertilization with the amount of 100, 200, 400kg per 10a or 50, 100, 200, 400kg per 10a respectively. Plant material was used Zantedeschia aethiopica 'Wedding March'. Among calcium chloride($CaCl_2$) and calcium carbonate($CaCO_3$), calcium chloride foliar application was more effective than calcium carbonate with basal fertilization to growth of common calla 'Wedding March'. In the 0.1% solution foliar application of calcium chloride, plant height, leaf length and length of cut-flower was more longer than control. Length of leaf petiole was more longer and leaf fresh weight was more heavier than control. The degree of petiole hardness was more effective in the 0.1% solution calcium chloride foliar application than any other treatment. In the silicate fertilization treatment, plant height of 50kg per 10a treatment was most highest as 73.9cm. also its length of leaf petiole and leaf fresh weight was more effective than any other treatment. The hardness of petiole was better in the 50kg per 10a silicate fertilizer treatment. The cell shape of leaf petiole was round and tissue was regular in the treatment of 0.1% calcium chloride and 50kg per 10a silicate fertilizer but the cell of control was irregular round type. Macro element content of calcium was more amount in the treatment of silicate 50kg per 10a basal fertilization. The infected ratio of Erwinia was no relation with lime and silicate fertilizer treatment. Lime fertilizer treatment is effective for growth and flowering of Calla than silicate fertilizer and the suitable concentration was 0.1%.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.751-761
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• 2019

Mt. Baekdu, Mt. Aso, Mt. Sakurajima, Mt. Kikai and etc are distributed around the Korean Peninsula. Recently signs of eruption of Mt. Baekdu are increasing, raising concerns over possible damage to volcanic ash from seasonal winds during the winter eruption. Therefore, detailed procedures for investigation and countermeasures for volcanic ash spread and damage are required. But the standards for the warning and alarm signal of volcanic ash presented by Korea Ministry of Government Legislation are vague, with "when damage is expected" and "when serious damage is expected". In this study, to analyze the damage threshold and to apply the cases of overseas damage to the country, a survey was conducted on the establishment of domestic spatial information by public institutions with public confidence. As a result of the investigation of damage from volcanic ash overseas, the details of the damage cases were different depending on the type of life or income sources of each country. Therefore, instead of applying the volcanic ash damage cases abroad in Korea, spatial information analysis was performed to reflect domestic social and natural characteristics. In addition, we selected the areas to be considered in the event of volcanic ash damage in Korea. Finally, domestic volcanic ash damages should be classified as health, residential, road, railroad, aviation, power, water, agriculture, livestock, forest, and soil. When establishing the volcanic ash alarm optimized for Korea in the future, overseas volcanic ash damage cases and domestic spatial information construction in this study will be helpful in policy establishment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.390-398
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• 2018

Miscanthus is a perennial energy plant that reproduces via rhizomes and has C4 metabolism. The flowering pattern of a wild type M. sacchariflorus (WTM) is affected by environmental conditions such as photoperiod and soil water status. Geodae-Uksae 1 (Geodea), which is a new M. sacchariflorus cultivar, has a lower heading rate than WMS; however the mechanism with why this happens is unknown. To confirm the effects of drought or waterlogging stresses on the growth of WTM and Geodea at the reproductive stage, we investigated variations in morphological characteristics and nutrient contents of the two Miscanthus species after four months of three water treatments. Morphological traits of the two Miscanthus species under the drought condition were similar to those under the control condition. But, the height of Geodea increased by 30% in response to the waterlogging stress. In WTM, the heading rate under the drought condition was lowest, while there was no significant difference between the waterlogging and control conditions. In the two Miscanthus species, nutrient contents, such as sucrose, total N, $P_2O_5$, K and Mg, were the highest under the drought condition, wherea Ca and Mg contents under the waterlogging condition were more than three times lower than those under the drought condition. The current study results showed that drought stress accelerated senescence and then inhibited nutrient mobilization in WTM, while waterlogging stress promoted the growth. This study is the first report to confirm that waterlogging stress promotes flowering of M. sacchariflorus.

• Journal of Plant Biotechnology
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• v.46 no.2
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• pp.119-126
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• 2019

This study was conducted to investigate the optimal culture method for gametophyte and sporophyte propagation in Coniogramme japonica (Thunb.) Diels, which can be used in various fields. The propagation of prothallus were cultured in 1/4 - 1 Murashige and Skoog medium and Knop medium for 10 weeks. The results indicated that the fresh weight of prothallus was the highest (14.5 g) in 1MS medium. Subsequently, various concentrations of sucrose, activated charcoal and nitrogen source were also added to 1MS medium and cultured for 8 weeks. The results provided that the sucrose concentration was 3% and the fresh weight of prothallus was the highest 10.8 g. According to the concentration in the range of 8.8 ~ 10.8 g, in the case of activated charcoal, the four treatments showed no significant difference. The nitrogen source was added at a concentration of 30, 60 and 120 mM with the ratio of ${NH_4}^+:{NO_3}^-$ being 1 : 2. As a result, the fresh weight of all treatments increased to similar level but there was no significant difference. We investigated sporophyte formation according to soil type and the highest number of sporophytes at 228.0 was formed in soils mixed with horticultural substrate and decomposed granite at 2 : 1 (v : v). On the other hand, sporophyte was not formed in soils containing peatmoss except for the one with peatmoss and decomposed granite at 2 : 1 (v : v).

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.345-349
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• 2019

In Korea, the mountainous area occupies more than 70% of the whole country, cutting of earth slope that cuts a part of the ground surface is widely used when building infrastructures such as road, railroad, and industrial complex construction. In recent years, regulations on environmental damage have become more strict, and various methods have been developed and applied. Among them, Concrete-Panel Retaining Wall technique is actively applied. Concrete-Panel Retaining Wall is a method to resist horizontal earth pressure by forming a wall by attaching a precast retaining wall to the front of the support material and increasing the shear strength of the disk through reinforcement of the support material. Soil nailing, earth bolt, and ground anchor are used as support material. Among them, ground anchor is a more aggressive reinforcement type that introduces tensile load in advance to the steel wire, and a large concentrated load acts on the front panel. This concentrated load is a factor that creates cracks in the concrete panel and reduces the durability of the retaining wall itself. In this study, steel pipe sleeves and reinforcements were purchased at the anchorage of the panel to prevent cracks, and by applying bumpy shear keys to the end of the panel, the weakness of the individual behavior of the existing grout anchors was improved. The problem of degraded landscape by exposure to front concrete of retaining wall and protrusion of anchorage was solved by the production of natural stone patterns and the construction of sections that do not protrude the anchorage. In order to verify the effectiveness of anti-crack sleeves and reinforcements used in the null, indoor testing and three-dimensional numerical analysis have been performed, and the use of steel pipe sleeves and reinforcements has demonstrated the overall strength increase and crack suppression effect of panels.