• Journal of the Korean GEO-environmental Society
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• v.16 no.10
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• pp.15-22
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• 2015

In this study, to evaluate the long-term behavior characteristics and the loss of prestress force, the long-term measurement of the tensile anchors in the actual construction was performed and the results were analyzed comparing with the existing estimation. As the reinforcement member used for the purpose of slope stability or uplift-resisting of the permanent structure, etc, the permanent anchor should maintain the functions during the performance period of the structure differently from the temporary anchor. However, as the time passes by, since the relaxation and the creep of the anchor occur constantly, the management for the loss of tensile force is essential to perform the functions stably. So far, the loss of the tensile force has been estimated according to the reduction of the prestress using elasticity theory and using the relaxation value according to the type of tension member and the test using the long-term measurement is limited. Therefore, in this study, the site condition and the ground were investigated for the tensile anchor in the actual construction and the long-term measurement results more than 500 days was analyzed by installing the loadcell, inclinometer and the groundwater level gauge. In addition, the long-term behavior characteristics were evaluated by comparing the disposition of the measured earth retaining wall and the tension force loss of the anchor with the existing interpretation results. In the evaluation results, the most of the tension force loss occurs within 90 days and the loss was measured less than the estimated values.

• Composites Research
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• v.32 no.6
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• pp.355-359
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• 2019

The high efficient water splitting system should involve the reduction of high overpotential value, which was enhanced by the electrocatalytic reaction efficiency of catalysts, during the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) reaction, respectively. Among them, transition metal-based compounds (oxides, sulfides, phosphides, and nitrides) are attracting attention as catalyst materials to replace noble metals that are currently commercially available. Herein, we synthesized optimal monodisperse Co₃[Co(CN)₆]₂ PBAs by FESEM, and confirmed crystallinity by XRD and FT-IR, and thermal behavior of PBAs via TG-DTA. Also, we synthesized monodispersed Co₃O₄ nanocubes by calcination of Co₃[Co(CN)₆]₂ PBAs, confirmed the crystallinity by XRD, and proceeded OER measurement. Finally, the synthesized Co₃O₄ nanocubes showed a low overpotential of 312 mV at a current density of 10 mA·cm^-2 with a low Tafel plot (96.6 mV·dec^-1).

• Journal of Animal Environmental Science
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• v.1 no.2
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• pp.125-136
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• 1995

To use the earth heat for the pig housing, an underground heat exchanger has constructed in depth of 2.5m and 20m length. The temperature of the outlet air was max. 8 kelvin higher than that of inlet air in winter season. In spite of the -7$^{\circ}C$ outside temperature, it could keep the air temperature from the earth tube above zero degree. The heating performance was maximum in value of 3.25Wh/㎥ and average of 1.75Wh/㎥ by the airflow volume of 340㎥/h. The slope of relative humidity from outlet air has shown gentler than that of inlet air. By using the underground heat exchanger, it would be possible to prepare an relatively uniform relative humidity in the swine stalls. The temperatures on the earth, where PVC pipes are buried, have shown 10~12$^{\circ}C$ on March. This can reduce the difference between day and night temperature during this season by using the underground heat exchanger.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.697-708
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• 1992

Liquid Chromatographic behavior of Ni(II) in Isonitrosoethylacetoacetate Imine(IEAA-NR), Ni(IEAA-NH)(IEAA-NR)(R = H, CH_3, C-2H_5, n-C_4H_9, C_6H_5-CH_2) chelates were investigated by reversed-phase HPLC on Micropak MCH-5 column using methanol/water as mobile phase. The optimum conditions for the separation of Ni(IEAA-NH)(IEAA-NR) chelates were examined with respect to the effect of the flow rate, sample solvent, mobile phase strength and column temperature. It was fo$und that metal chelates were properly eluted in an acceptable range of capacity factor value(0{\le}logk'{\le}1). The dependence of the logarithm of capacity factor (k') on the volume fraction of water in the binary mobile phase as well as on the liquid-liquid extraction distribution ratio (Dc) in methanol-water/n-alkane extraction system showed the good linearties, and the dependence of the logarithm of capacity factor (k') on the column temperature and on the enthalpy exhibited the good linearties, and the compensation temperature ({\beta}) from the slope was 773.47{\circ}K. It was suggested that the retention of metal chelates was largely affected by the hydrophobic effect.

• Journal of Environmental Science International
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• v.19 no.4
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• pp.415-425
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• 2010

The purpose of the present study was to analyze the vegetation structure and distributional characteristics of Abies koreana forests in Mt. Halla, and to provide basicdata for an ecological study on Abies koreana in Mt. Halla. The results of the analysis showed that the mean importance percentage(M.I.P,) of Abies koreana in the Youngsil and Bangaeoreum and the Azalea field were 28.3%, 23.6%, and 46.4%, respectively. The ratios of DBH (diameter at breast height) to height were similar in all region, except in the Azalea field, where Abies koreana of various ages, both young and old, were found. The species diversity (H) of the upper and lower layers in the Youngsil and Bangaeoreum and in the Azalea field were 0.625 and 0.810, 0.731 and 0.848, and 0.342 and 0.757, respectively. A total of 52 community were distributed at locations higher than 1,300m above sea level. The proportions of each community in the whole Abies koreana forest were 56.5%(Azalea field), 11.0% (Youngsil trail at 1,550-1,650 m above sea level), and 8.1%(Janggumok and Kundurewat region). The total area of the Abies koreana forest was calculated to be 795.3ha by combining all the areas of each community. An Abies koreana forest with the largest area was found at locations 1,500-1,600 m above sea level, taking up 38.8% of the total Abies koreana forest area. For the slopes of the distributional area of Abies koreana, 46.1%(highest proportion) of the total area was $10\sim25^{\circ}$, and for the azimuth of the distributional area, 17.4%(the highest proportion) of the total area was $0-45^{\circ}$. The vegetation structure showed large differences between areas. It was found, however, that the distribution was mostly in the areas with a relatively gentle slope. It is suggested that research be done to forecast the possible changes in the differences in the vegetation structures between different areas caused by climate changes. In addition, there is a need to monitor the Abies koreana and alpine plants in the subalpine zones of Mt. Halla, which are sensitive to climate change, to obtain the basic data that are necessary for the protection and maintenance of the ecosystem.

• Biomedical Science Letters
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• v.3 no.2
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• pp.107-114
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• 1997

Recent reports indicate that the clinical usefulness of prostate specific antigen (PSA), particulary in the differentiation of benign prostate hyperplasia from prostate cancer, can be improved by measuring the amount of free PSA in serum. Measuring free PSA is especially useful in attempts to improve diagnositc performance of PSA in the diagnostic gray zone of total PSA. The objective of this study was to develop free PSA assay kit using sandwich microplate enzyme immunoassay format. We chose a test format with polyclonal anti-PSA antibodies coated on the wells and monoclonal anti-free PSA antibodies for quantification to gain higher test sensitivity. We adpoted 10 uL of specimen and 2 hours of first incubation time with detecting antibody for free PSA EIA format using microplate. The within-day and between-day precision (%CV) in the high and low concentration ranges were below 4%. The correlation coefficient between in-house free PSA assay and commercial assay kit was r=0.9965 (slope=0.0984, y intercept=0.0173, N=27). No hook effect was found by 40 ng/mL and correlation coefficient (r) value of the fitted linear regression was over 0.995. The recovery tests were in the range of 98.9∼104.1％ for free PSA. In conclusion, in-house free PSA enzyme immune assay is cost effective, simple and rapid and could be useful for the prognosis after theraphy as well as for the differential diagnosis between prostate cancer and benign prostate hyperplasia.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.2
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• pp.87-90
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• 1974

The followings are the results of study about morphological variation of mussel, Mytilus coruscus collected respectively from Sanyang-myeon Tongyeong-goon Gyeongnam on 13th January, Yeonwha-do Yokji-myeon Tongyeong-goon Gyeongnam on 15th May and down below the Yeong-do Bridge Busan on 20th August, 1964. The biggest mussel of the above three areas have been from Yeong-do Bridge, whose shell height is 164.1 mm, shell length 77.8mm, shell breadth 52.2mm, total weight 291,9g and shell length is as follows : from Yeong-do Bridge L=0.4954H + 1.9516, from Sanyang-myeon L=0.3718H + 14.145, from Yeonwha-do L=0.4074H + 9,6610 The relationship between shell height and shell breadth is as follows : from Yeong-do Bridge B=0.3426H + 0.2052, from Sanyang-myeon B=0.3084H + 3.6183, from Yeonwha-do B=0.3507H + 0.8028 In view of the above relationship, it is concluded that the slope value of mussel, nearer to the inshore from the off-sea, is similar to that of M. edulis, from which are can presume that M. coruscus could be changed in shell form according to its environment. Growth curve between total weight and shell height is as follows : from Yeong-do Bridge W=0. 00020469 $$H^{2.79745}$ from Sanyang-myeon W=0.00061512$H^{2.53708}$ from Yeonwha-do W=0.00016965$H^{2.83960}$

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.259-266
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• 2020

In this study, required drill bits and excavation methods were developed for an uneven drilling method that can solve the problem of performance degradation of rock bolts. The developed drill bit's excavation performance was verified using rock with a strength of 100 MPa or more. In addition, for the relative evaluation of the uneven excavation method, experimental specimens were prepared for models with and without irregularities, and tests were performed. As a result of the experiment, the model with unevenness exhibited an average critical draw resistance of 801.6 kN, which is about 1.7 times the value of 468.7 kN for the model without unevenness, thus confirming the effect sufficiently. Therefore, it is expected that the resistance performance will significantly increase despite an increase in the uneven hole diameter of 20 mm. In the future, the results of this study could be used as basic data when performing other studies using numerical analysis models and performance verification through experiments to obtain an optimized rock forming method.

• The Korean Journal of Mycology
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• v.27 no.3 s.90
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• pp.237-241
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• 1999

To search for less toxic antiviral agents from Basidiomycetes, the water soluble components (=EA), were isolated from the carpophores of Elfvingia applanata (Pers.) Karst. Anti-varicella zoster virus (Oka strain; anti-VZV/Oka) activity of EA was examined in MRC-5 cells by plaque reduction assay in vitro. And the combined antiviral effects of EA with interferon (IFN) alpha or IFN gamma were examined on the multiplication of VZV/Oka. EA exhibited a dose-dependent reduction in the plaque formation of VZV/Oka with 50% effective concentration $(EC_{50})$ of $464.14\;{\mu}g/ml$. The results of the combination assay were evaluated by the combination index (CI) that was calculated by the multiple drug effect analysis. The combination of EA with IFN alpha showed partially synergistic or additive effects with CI values of $0.83{\sim}1.09$ for 50%, 70%, 90% effective levels, and those with IFN gamma showed antagonism with CI values of $1.20{\sim}1.24$.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.91-101
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• 2006

This study was conducted to analyze the relationships between distributions of major hardwood species and characteristics of topography in natural hardwood forest at Mt. Joongwang, Pyongchang-gun, Gangwon-do which belongs to mid-northern part of the temperate forest. Acer pictum var. mono, Acer manshuricum and Quercus mongolica were affected by elevation, while Ulmus davidiana var. japonica and Fraxinus rhynchophylla were affected by the change of slope. Importance values of A. pictum, Betula costata, Ulmus laciniata and Cornus controversa in valley were 13.41%, 5.68% and 3.29%, respectively, which were higher than in any other topography. Species diversity of valley was the highest with 0.98. Ratio of A. pictum and Q. mongolica in dominant species were 24% and 14%, respectively in valley, while were 19% and 23% in slop. Q. mongolica ratio in ridgeline was higher than any other species. Importance values of A. pictum increased continuously until elevation 1,200 m. importance values of F. rhynchophylla was 6.6% which was the highest value found on elevation 800 m. Distributions of major hardwood species were different according to the elevation. The ratio of Q. mongolica and A. pictum were 6.4%~17.5% and 6.0%~10.7% respectively, which were the highest ratio. Species diversity increased according to the increase of the elevation.