• Korean Journal of Soil Science and Fertilizer
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• v.14 no.1
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• pp.37-43
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• 1981

This pot experiment was conducted to find out the optimal fertilization ratio of the cations(K: Ca: Mg) in various soil conditions. Soil samples were collected from uncultivated mountains and hills where development for grass lands is under consideration. The optimum ratios were computed by the Homes systematic variation technique. The results were summarized as follows : 1. The optimum fertilization ratios of the cations (K : Ca : Mg) for the high yields of grass-clover mixed sward at various areas were obtained (Table 4) 2. The relatively high optimum fertilization ratios of K in Daegu and Taegwalryong, Ca in Unbong, and Mg in Cheju district gave the high yields of clover in mixed sward. They were positively related to the low contents of the above cations in the soils or the relatively low content ratio comparing with other cations. 3. The yields of clover in mixed sward were seriously affected by the changes in both the fertilization ratio and total concentration of cations comparing to those of the grass yields. As a consequence, total yields, quality, and botanical composition of the mixed sward were also affected. 4. The antagonis among the cations K, Ca, and Mg was known from the point of mineral contents of grass and clover. 5. The equivalent ratio K/(Ca+Mg) or grass was greatly increased by the range of 2.4 and 3.3 in the K-group treatment, which was higher than the critical level 2.2 of grass tetany, otherwise that. of clover by the range of 0.9 and 1.2. Therfore, it may be concluded that if the botanical composition of grass/legume sward is optimum, the incidence of grass tetany can be eliminated.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.158-166
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• 2017

The object of this study was to improve tomato seedling quality in low temperature(below 7, $10^{\circ}C$ during night time or daily mean air temperature was $18^{\circ}C$) by application of silicate fertilizer. Six different silicate fertilizer concentrations (8, 16, 32, 64, 128, and 256mM) or water as the control were applied to tomato seedlings twice a week for 20 days. Positive effects were observed in the growth parameters of the seedlings treated with 16 and 32mM silicate fertilizer; the most effective concentration of silicate at which seedlings showed the best performance was 16mM. However, a high concentration of silicate (256mM) caused negative effects on the growth. The transpiration rate decreased alongside with the increase of silicate concentration up to 32mM, possibly due to the increased stomatal diffusive resistance. Silicate stimulated the growth and development of tomato seedlings, resulting in increased growth parameters and root morphology. However, no significant differences were observed among treatment numbers of soil-drenching wuth the silicate (6, 10, or 20 times with 16mM) for 20 days, suggesting that silicate treatment with 6 times may be sufficient to induce the silicate effects. The application of 16mM of silicate fertilizer reduced relative ion leakage and chilling injury during low temperature storage. In addition, the seedlings treated with silicate fertilizer recovered faster than those without silicate treatment after low temperature storage.

• Journal of the Korean Applied Science and Technology
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• v.37 no.5
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• pp.1323-1329
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• 2020

To characterize the molecular structure of PhE-gal synthesized using Escherichia coli 𝛽-gal, NMR (¹H- and ¹³C-) spectroscopy and mass spectrometry of PhE-gal were conducted. ¹H NMR spectrum of PhE-gal showed multiple peaks corresponding to the galactosyl group, which is an evidence of galactosylation on 2-phenylethanol (PhE). Downfield proton peaks at 𝛿_H 7.30~7.21 ppm showed the presence of aromatic protons of PhE as well as benzyl CH₂ protons at 𝛿_H 2.88 ppm. Up field proton peaks at 𝛿_H 4.31 ppm, 4.07 ppm and multiple peaks from 𝛿_H 3.86~3.38 ppm are indicative of galactocylation on PhE. ¹³C NMR spectrum revealed the presence of 12 carbons suggestive of PhE-gal. Among 12 carbon peaks from PhE-gal, the four peaks at 138.7, 129.0, 128.6 and 126.5 were assigned aromatic carbons in the phenyl ring. Three peaks at 129.0, 128.6 and 126.5 showed high intensities, indicating CH aromatic carbons. ¹³C NMR data of PhE-gal showed 6 monosaccharide peaks from galactose and 2 peaks from aliphatic chain of PhE, indicating that PhE-gal was galactosyl PhE. The mass value (sodium adduct ion of PhE-gal, m/z = 307.1181) from mass spectrometry analysis of PhE-gal, and ¹H and ¹³C NMR spectral data were in good agreement with the expecting structure of PhE-gal. We are expecting that through future study it will eventually be able to develop a new additive with low cytotoxicity.

• Korean Journal of Optics and Photonics
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• v.18 no.6
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• pp.452-460
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• 2007

Ultra-low loss ZERODUR and fused silica mirrors were manufactured and their light scattering characteristics were investigated. For this purpose, ZERODUR and fused silica substrates were super-polished by the bowl feed method. The surface roughness were 0.292 ${\AA}$ and 0.326 ${\AA}$ in rms for ZERODUR and fused silica, respectively. To obtain the high reflectivity, 22 thin film layers of $SiO_2$ and $Ta_2O_5$ were deposited by Ion Beam Sputtering. The measured light scattering of ZERODUR and fused silica mirror were 30.9 ppm and 4.6 ppm, respectively. This shows that the substrate surface roughness is not the only parameter which determines the light scattering of the mirror. In order to investigate the mechanism for additional light scattering of the ZERODUR mirror, the surface roughness of the mirror was measured by AFM and was found to be 2.3 times higher than that of the fused silica mirror. It is believed that there is some mismatch at the interface between the substrate and the first thin film layer which leads to the increased mirror surface roughness. To clarify this, the contact angle measurements were performed by SEO 300A, based on the Giriflaco-Good-Fowkes-Young method. The fused silica substrates with 0.46 ${\AA}$ in its physical surface roughness shows lower contact angle than that of the ZERODUR substrate with 0.31 ${\AA}$. This indicates that the thin film surface roughness is determined by not only its surface roughness but also the surface energy of the substrate, which depends on the chemical composition or crystalline orientation of the materials. The surface energy of each substrate was calculated from a contact angle measurement, and it shows that the higher the surface energy of the substrate, the better the surface roughness of the thin film.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.67-75
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• 1976

This experiment was studies for grassland establishment on west coastal saline land in Korea from May 1975 to March 1976 and used seeds were introduced from Australia. The results of adaptability were summarized as follow. 1. The seeds germination percentage was not influence in 0.5% salt included, but delayed days in 1% salt included and decreased germination percentage. 2. Any experimental grasses species were not growth on the 0.5% salt included soil and also growth was much damaged on the 0.05% salt included soil. It was suggested that $Mg^+$, $K^+$ ions involved with $Na^+$ ion. 3. The yield of grasses were much decreased on 0.05% salt included soil which compared control group. The yield rate of decrease were 30% in kikuyu, 60% in strawberry clover, 63% in reed canarry and 89% in orchard grass. 4. For winter-hardness test, nearly all the species well overwintered but except kikyu. 5. One of salt tolerance native grass (Agrostis distans crieseb var coreensis, Hackel) was discovered in saline area, and it was growth from middle of May to Middle of September. Also it was known that the native grass was good feed stuff but it was not so long in growth life. 6. It was concluded that more experimental work must be carried out to select of salt tolerance grass for grassland establishment on saline by introduce some more species such like saltgrass, saltbush, shadsclae from foreign land.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.253-259
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• 2011

In this studies, contents and activities of antioxidative substances in the fruits of a pear cultivar and five Korean wild pear lines were investigated. The content of total phenolic compounds was highest with Pyrus pyrifolia var. culta "Shingo" (7.68 $mg{\cdot}g^{-1}$, D.W.) while total flavonoids was highest with P. ussuriensis var. acidula (5.66 $mg{\cdot}g^{-1}$, D.W.). The contents of total polyphenols and flavonoids varied according to plant species, but in general pyrifolia lines had higher total polyphenols than total flavonoids whereas in ussuriensis lines total flavonoid contents were higher than total polyphenols. The scavenging effects of DDPH radicals was highest with highest with P. ussuriensis var. seoulensis ($RC_{50}$=1.45 $mg{\cdot}mL^{-1}$) and that of ABTS radicals was highest with P. ussuriensis var. acidula ($RC_{50}$=0.69 $mg{\cdot}mL^{-1}$). A pear cultivar "Shingo" showed highest total polyphenol content, but scavenging activity of DDPH and ABTS radicals was lowest. The fruits of P. ussuriensis var. seoulensis contained low level of phenolic compounds, but their scavenging effects on two radicals was superior. Ferrous ion chelating effect was high in P. pyrifolia var. culta (98.93%), and in P. ussuriensis var. sinensis (68.71%), but two species had low scavenging activity. The content of phenolic compounds in wild pears was not always directly proportional to the radical scavenging activity. Neither radical scavenging activity was to ferrous ion chelating activity. In conclusion the fruits of P. ussuriensis var. acidula, P. ussuriensis var. seoulensis, and P. ussuriensis var. sinensis had great potential for the development of new antioxidative functional food because their antioxidative activity is higher or at least similar to P. pyrifolia var. culta. However, due to their different levels of antioxidative effects, the development of methods of using them jointly, not singly, to obtain maximum level of antioxidants is recommended.

• Clean Technology
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• v.24 no.1
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• pp.77-84
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• 2018

In this study, $Li_4Ti_5O_{12}$ anode materials for lithium ion battery were synthesized by dry ball-mill method. Polyvinyl chloride (PVC) as a carbon source was added to improve electrochemical properties. When the PVC was added after $Li_4Ti_5O_{12}$ formation, the spinel structure was well synthesized and it was confirmed by X-ray diffraction (XRD) experiments. When the carbon material was added before the synthesis and the heat treatment was performed, it was confirmed that a material having a different crystal structure was synthesized even when a small amount of carbon material was added. In the case of $Li_4Ti_5O_{12}$ without the carbon material, the electrical conductivity value was about $10{\mu}S\;m^{-1}$, which was very small and similar to that of the nonconductor. As the carbon was added, the electrical conductivity was greatly improved and increased up to 10,000 times. Electrochemical impedance spectroscopy (EIS) analysis showed that the size of semicircle corresponding to the resistance decreased with the carbon addition. This indicates that the resistance inside the electrode is reduced. According to the Cyclic voltammetry (CV) analysis, the potential difference between the oxidation peak and the reduction peak was reduced with carbon addition. This means that the rate of lithium ion insertion and deinsertion was increased. $Li_4Ti_5O_{12}$ with 9.5 wt% PVC added sample showed the best properties in rate capabilities of $180mA\;h\;g^{-1}$ at 0.2 C-rate, $165mA\;h\;g^{-1}$ at 0.5 C-rate, and $95.8mA\;h\;g^{-1}$ at 5 C-rate.

• Analytical Science and Technology
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• v.29 no.1
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• pp.19-28
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• 2016

The objective of this study was to determine the acidification of precipitation in the Jeju area. Precipitation samples were collected from the Jeju area from 2009-2014, and the major ionic species were analyzed. In the regression analysis, through a comparison of ion balance, electric conductivity, and acid fraction, the correlation coefficients showed a good linear relationship within the range of 0.927~0.983. The volume-weighted means of the pH and electric conductivity were 4.9 and 22.7 µS/cm, respectively. The ionic strength of precipitation was 0.27±0.38 mM, indicating about 35.9 % of total precipitation within the pure precipitation criteria. The volume-weighted mean concentrations (ìeq/L) of the ionic species in the precipitation were in the order of Na⁺ > Cl⁻ > nss-SO₄²⁻ > NO₃⁻ > NH₄⁺ > Mg²⁺ > H⁺ > nss-Ca²⁺ > PO₄³⁻ > K⁺ > HCOO⁻ > CH₃COO⁻ > NO₂⁻ > F⁻ > HCO₃⁻ > CH₃SO₃⁻ . The acidification contributions by sulfuric and nitric acids were 54.5 % and 36.5 %, respectively. Meanwhile the acidification contributions by formic and acetic acids were 4.8 % and 4.2 %, respectively. Thus, it was found that the acidification of the precipitation in the Jeju area was mainly due to the inorganic acids. The neutralization factors by NH₃ and CaCO₃ were also 33 % and 20 %, respectively.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.3
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• pp.130-143
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• 1997

To investigate geochemical characteristics and the sources of the dissolved ion species in the river water in the Han river drainage basin, samples were collected at 60 sites from the Han river drainage basin. The data for. pH, conductivity, TDS (total dissolved solid), temperature, and concentrations of dissloved ions were obtained as follows : (1) The geochemical characteristics of the surface water in the South and North Han river drainage basins are mainly controlled by bed rock geology in the drainage basin and in the main stream of the Han river considerably affected by anthropogenic pollution. The South Han river water samples have high concentrations of $Ca^{2＋}$ (ave. 15.42 ppm), $Mg^{2＋}$ (ave. 2.74 ppm), HC $O_3$$^{[-10]}$ (ave. 51.9 ppm), which evidently indicates that the bed rock geology in a limestone area mainly controls the surface water chemistry. The concentration of S $O_4$$^{2-}$ is remarkably high (SHR10-2 : 129.9 ppm) because of acid mine drainage from the metal and coal mines in the upper reaches of the South Han river. (2) The South Han river and the North Han river join the Han river. in the Yangsuri, Kyounggido and flow through Seoul metropolitan city. The mixing ratio is about 60:40 at the meeting point (sample number HRl0). (3) The result of factor analysis suggests that the pollution factor accounts for about 79% and the bed rock type factor accounts for about 7% of the data variation. This means that the geochemical characteristics of the Han river water mainly controlled by anthropogenic pollution in the South Han river and main stream of the Han river drainage basin. (4) The chemical data for four tributaries such as the Wangsukcheon, the Tancheon, the Zunuangcheon, and the Anyangcheon show that the concentration of pollution elements such as N $O_2$, C $l^{－}$, P $O_4$$^{3-}$, S $O_4$$^{2-}$ and Mn are high due to municipal waste disposal.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.415-423
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• 1995

This study was conducted to analyze the chemical composition, nutritional contents, and saponin in the xylem sap of Acer mono Max. From Feb 25 to Mar 4, 1994, spring sap was collected by making holes with 1.7cm diameter on the trunk of trees in Mt. Baekwoon and Mt. Jiri. Sugars were quantified by HPIC, amino acids by amino acid analyzer, saponins by TLC, HPLC, and $^1H$ & $^{13}C$ NMR. Major component of the sap was sucrose at a concentration range of 0.68 to 2.01%. Following minor components were found: glucose at 0.03-0.11%, and fructose at 0.01-0.03% as sugars, lipid at 0.03%, threonine at 0.152%, lysine at 0.038%, arginine at 0.068% as amino acids, ash at 0.1%, Ca at 175ppm, Fe at 2ppm, P at 19ppm, K at 16ppm, Na at 31ppm as minerals, vitamin $B_1$ at 0.6ppm, vit. $B_2$ at 0.1ppm, and vit. C at 19ppm. A trace of phenolic compounds was found by TLC, while saponin commonly reported in high-quality ginseng roots was not found in maple sap. It is concluded that sap of Acer mono contains a good variety of natural compounds such as sugars, amino acids, Ca, Fe, and vitamins to serve as an excellent source of very natural and health-promoting drink.