• Journal of Wetlands Research
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• v.26 no.1
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• pp.62-71
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• 2024

To assess the ecological changes of Korean fir (Abies koreana E. H. Wilson) under climate change conditions, growth and physiological responses were analyzed over a 5-year period in a control group (outdoors) and in a treatment group where the temperature and CO2 levels were elevated to closely resemble RCP 4.5 conditions. The results showed an increasing trend in annual branch length of A.koreana in the climate change treatment group over time. While climate change conditions did not significantly impact the morphological differences of A.koreana leaves, they did influence the biomass of the leaves, suggesting that as climate change progresses, the productivity of A.koreana leaves may decline. On the other hand, the chlorophyll content in A.koreana under climate change conditions was higher in the climate change treatment group, whereas the photosynthesis rate, transpiration rate, water use efficiency and stomatal conductance was higher in the control group. This suggests that an environment with elevated temperature and CO2 could influence an increase in stomatal density, but having a negative impact on photosynthetic reactions. Further research on stomatal density under each environmental treatment will be required to confirm this hypothesis. Additionally, as this study only observed changes in leaf biomass, further empirical research should be considered to understand the changes in biomass of A.koreana under climate change conditions. In conclusion, the environmental adaptability of A.koreana is expected to weaken in the long term under elevated temperatures and CO2.

• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.660-667
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• 2017

Equilibrium data of the mixture is essential in the design and operation of separation equipment such as distillation or extraction in chemical processes. These equilibrium data can be obtained through experiments or by calculations using the known binary parameters and the thermodynamic models. Generally, to obtain these parameters, phase equilibrium experimental data such as gas-liquid and liquid-liquid are used. In this study, the excess enthalpy of the mixture was measured using the flow type microcalorimeter which is a simpler method than phase equilibria experiments, and the parameters of various theories were obtained by using this data. In order to investigate the relationship between carbon chain length, enthalpy and binary parameters in the alkane system, excess enthalpies for the n-hexane + alkane (n-pentane, n-heptane, n-octane and n-dodecane) were measured at 298.15 K and the banary interaction parameters of Wilson, NRTL, and UNIQUAC were obtained from the experimental data. In addition, we wanted to obtain basic information on the interaction and association phenomena of the system including electrolyte applicable to various fields by using the excess enthalpy experimental data and the existing theory. First, we investigated the excess enthalpy for the NaOH / Water / Ethanol system as a basic experiment and examined the applicability using the electrolyte-NRTL (eNRTL) theory.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.723-729
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• 2015

The moment analysis of cyclic adenosine monophosphate (cAMP) was performed using chromatograms that were obtained with the pulse input method from an octadecyl silica (ODS) high-performance liquid chromatography (HPLC) column. The general rate (GR) model was employed to calculate the first absolute moment and the second central moment. Three important coefficients for moment analysis, which are molecular diffusivity ($D_m$), external mass transfer coefficient ($k_f$), and intra-particle diffusivity ($D_e$), were estimated by the Wilke-Chang equation, Wilson-Geankoplis equation, and comparing van Deemter equation to theoretical plate number equation, respectively. Experiments were conducted by various conditions of flow rates, methanol volume ratio of the mobile phase, and solute concentration. After the moment analysis, results were organized by van Deemter plots. Also van Deemter coefficients were compared each other to effect $H_{ax}$, $H_f$, and $H_d$ on height equivalent to a theoretical plate (HETP, $H_{total}$). The value of intraparticle diffusion ($H_d$) was the primary factor which makes for HETP whereas external mass transfer ($H_f$) was disregardable factor.

• Journal of the Korean earth science society
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• v.39 no.3
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• pp.260-274
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• 2018

The purpose of this study was to propose curriculum and teaching sequence for seasonal change by exploring a learning progression. For the purpose, 4 steps of construct modeling approach (specifying construct, item design, outcome space, and measurement model) proposed by Wilson (2005) was applied. In the stage of specifying construct, 'length of shadow according to seasons', 'position of constellation according to seasons', 'seasons of the southern hemisphere and northern hemisphere', 'cause and phenomenon of seasonal change' were selected as the subconstructs of seasonal changes, and constructed a construct map showing the level of development from level 1 to level 4 for each subconstruct based on the results of the previous research. In the item design stage, we developed five assessment items consisting of 3 items in the form of C-E (choose and explain) and two items in the form of CR (constructed response), applied it to 383 elementary, middle and high school students. In the outcome space stage, the students' responses to the assessment items were categorized based on the construct map. The categories were classified into 4 levels according to student ability and scores of 1-4 were given. In the measurement model stage, we applied the partial credit model of the Rasch model and compared whether the learning pathway created from the results of students' response coincides with the construct map. Based on the results of the research, we modified the construct map and finally created hypothetical learning progression on seasonal change. Finally, we proposed an orientation of curriculum amendment and effective teaching sequence for seasonal change.

• Applied Biological Chemistry
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• v.43 no.1
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• pp.52-56
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• 2000

The influence of the 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)-N-phenyl- propionamide derivatives on the herbicide activities against rice plant with pre-emergence and post-emergence in down land were examined and the structure activity relationship (SAR) were analyzed by Free-Wilson and Hansch method. In pre-emergence, the SAR approach is shown that the optimal, $({\pi})_{opt}=0.91$, hydrophobicity with electron donating effect of the ortho substituted mono substituents and 2,3,4-substituted three substituents were found to be contribute the herbicidal activity. Whereas, in post-emergence, the optimal, ({\pi})_{opt}=0.50$, hydrophobicity with electron withdrawing effect of meta substituted mono subsituents and 2,3-substituted two substituents were found to be contribute the herbicide activity. The herbicide activities with post-emergence more increase than that of pre-emergence. It is assumed from the SAR equations that the 2-methyl-3-methoxy-4-cyano group substituent is selected as the most lowest herbicide activity against rice plant with post-emergence in green house. The hydrolysis reaction was proceeded through nucleophilic addition-elimination (Ad_{Nu-E})$ with the orbital control between LUMO of substrate and HOMO of water molecule. And molecular electrostatic potential (MEP) of none (H) substituent was discussed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.6
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• pp.17-27
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• 2011

Prunus serrulata var. serrulata f. spontanea (E. H. Wilson) C. S. Chang was treated with dried swine excrement at various concentration levels, and their growth reactions and the contents of total kjeldahl nitrogen and total phosphoric acid were analyzed. The result is as follows; 1. When the plants were treated with 0.25% of dried swine excrement, the seed germination rate of Prunus serrulata var. serrulata f. spontanea was higher than that of the control. However, it showed a tendency to decrease when the treatment concentration got higher than 0.25%. 2. The growth rate of species was highest when they were treated with 0.25% of dried swine excrement. It tended to decrease with higher treatment concentration than 0.25%. Significant difference was clear between the control and the experimental plants of Prunus serrulata var. serrulata f. spontanea. 3. The contents of nitrogen and phosphoric acid in Prunus serrulata var. serrulata f. spontanea also got higher as the concentration of dried swine excrement increased. However, the content of total kjeldahl nitrogen was highest in the leaves, and followed by the roots and stems. In contrast, the content of total phosphoric acid were highest in the roots, and followed by the leaves and stems. Therefore, stems had the lowest contents of both nitrogen and phosphoric acid. 4. The contents of total kjeldahl nitrogen and total phosphoric acid in the soil were measured before and after the growth experiment of Prunus serrulata var. serrulata f. spontanea treated with dried swine excrement. The contents of nitrogen and phosphoric acid significantly decreased after the experiment. In conclusion, the contents of total kjeldahl nitrogen and total phosphoric acid accumulated in the plants increased as the concentration level of dried swine excrement got higher. The seed germination and plant growth rates were best at 0.25% treatment of dried swine excrement. The treatment of dried swine excrement may bring high effects on increasing the plant growth rate but could damage the plants with higher concentration than they need. Different optimal concentration levels of dried swine excrement for different plants should be found before it is used as fertilizer.

• Journal of the Korean Wood Science and Technology
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• v.41 no.6
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• pp.551-558
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• 2013

Ethanol extracts from Rhododendrom brachycarpum and Abies koreana were investigated for their anti-allergic activities using RBL-2H3 cell line. After treatment with ethanol extracts of various concentrations on the immune response induced mast cell by concanavalin A (Con A), the expressions of cytokine interleukin-4 (IL-4), interleukin-13 (IL-13) were determined by using RT-PCR and the degranulation of mast cells was determined by measuring ${\beta}$-hexosaminidase release. Expression level of IL-4 was decreased by the extract from Rhododendrom brachycarpum in $10^{-7}$, $10^{-5}$ and $10^{-3}%$ concentrations. Expression level of IL-13 was also decreased by both extracts. ${\beta}$-Hexosaminidase release by RBL-2H3 cells was inhibited at the $10^{-5}$ and $10^{-3}%$ concentration of extracts from Rhododendrom brachycarpum and Abies koreana, respectively. These results demonstrate that ethanol extracts of Rhododendron brachycarpum and Abies koreana exert anti-allergic effects by regulating the reduction of IL-4 and IL-13 genes expression and also the secretion of ${\beta}$-hexosaminidase.

• Clean Technology
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• v.25 no.2
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• pp.140-146
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• 2019

Flammable substances, such as organic solvents, are commonly used in laboratories and industrial processes. The flash point of flammable liquid mixtures is a very important parameter for characterizing the ignition and explosion hazards, and the flash points of mixtures of $C_2{\sim}C_3$ alcohols and 2,2,4-trimethylpentane were measured in the present study. The 2,2,4-trimethylpentane is an important component of gasoline and is frequently used in the petroleum industry as a solvent. Lower flash point data were measured for the binary systems {ethanol + 2,2,4-trimethylpentane}, {1-propanol + 2,2,4-trimethylpentane}, and {2-propanol + 2,2,4-trimethylpentane}. The flash point measurements were carried out according to the standard test method (ASTM D3278) using a Stanhope-Seta closed cup flash point tester. The measured flash points were compared with the predicted values calculated using Raoult's law and also following $G^E$ models: Wilson, Non-Random Two Liquid (NRTL) and UNIversal QUAsiChemical (UNIQUAC). These models were able to predict the experimental flash points for different compositions of {$C_2{\sim}C_3$ alcohols + 2,2,4-trimethylpentane} mixtures with minimal deviations. The average absolute deviation between the predicted and measured lower flash point was less than 1.28 K. A minimum flash point behaviour was observed in all of the systems as in the many observed cases for the hydrocarbon and alcohol mixtures.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.36-36
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• 2019

본 연구는 한라산국립공원 동사면에 위치한 구상나무숲 장기생태 모니터링 5ha 조사지역 ($20{\times}20m$, 125개 방형구)에서 구상나무의 유묘 및 치수 발생 현황을 파악하기 위하여 수행되었다. 조사는 2016년 6~8월 사이에 $5{\times}5m$ 방형구 125곳에 대해 계통추출법을 적용하여 실시하였다. 조사한 전체 125개 방형구 중에서 54개에서만 유묘가 관찰되었으며, 그 내용은 유묘 615개체 및 치수 1개체로 총 616개체가 발견되었다. 그러나 과반수의 71개 방형구에서 치수뿐만 아니라 유묘도 출현하지 않았다. 심지어 전체 125개 방형구에서 유묘가 가장 많이 관찰된 방형구(2-6지역, 95개체)를 제외하면, 나머지 124개 방형구의 평균 유묘 개체수는 4.2개로 매우 적었고 높이도 35cm 이하에 불과했다. 이와 함께 장기생태 모니터링 조사 지역 내에서 $1{\times}1m$ 방형구 183곳에 대해 단순 무작위 추출법으로 발생지 조사를 수행하였다. 발생지 조사 결과 유묘 2,518개체, 치수 2개체 및 유목 2개체 등 총 2,522개체가 발견되어 계통추출법을 적용한 조사와 유사한 결과가 나타났다. 본 연구를 통해 한라산국립공원 동사면 구상나무숲 내에서 구상나무 유묘의 발생은 어느 정도 이루어지고 있으나, 교란으로 인하여 치수로의 발달이 제한되는 것으로 판단된다. 여러 교란 요인 중에서 조사된 총 3,138개체 중 12.1%, 381개체에서 유제류인 노루에 의한 섭식이 확인되어 노루의 섭식이 유묘 발생 및 치수 발달에 교란을 야기하는 가장 중요한 요인으로 추정해볼 수 있다. 한반도 특산식물 구상나무의 보전 대책 수립을 위한 유묘 및 치수 교란 원인에 대한 지속적인 모니터링이 진행되어야 한다고 사료된다.

• Korean Journal of Remote Sensing
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• v.39 no.3
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• pp.325-338
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• 2023

Korean fir (Abies koreana Wilson) is one of the most important environmental indicator tree species for assessing climate change impacts on coniferous forests in the Korean Peninsula. However, due to the nature of alpine and subalpine regions, it is difficult to conduct regular field surveys of Korean fir, which is mainly distributed in regions with altitudes greater than 1,000 m. Therefore, this study analyzed the vegetation change trend of Korean fir using regularly observed remote sensing data. Specifically, normalized difference vegetation index (NDVI) from Moderate Resolution Imaging Spectroradiometer (MODIS), land surface temperature (LST), and precipitation data from Global Precipitation Measurement (GPM) Integrated Multi-satellitE Retrievalsfor GPM from September 2003 to 2020 for Hallasan and Jirisan were used to analyze vegetation changes and their association with environmental variables. We identified a decrease in NDVI in 2020 compared to 2003 for both sites. Based on the NDVI difference maps, areas for healthy vegetation and high mortality of Korean fir were selected. Long-term NDVI time-series analysis demonstrated that both Hallasan and Jirisan had a decrease in NDVI at the high mortality areas (Hallasan: -0.46, Jirisan: -0.43). Furthermore, when analyzing the long-term fluctuations of Korean fir vegetation through the Hodrick-Prescott filter-applied NDVI, LST, and precipitation, the NDVI difference between the Korean fir healthy vegetation and high mortality sitesincreased with the increasing LST and decreasing precipitation in Hallasan. Thissuggests that the increase in LST and the decrease in precipitation contribute to the decline of Korean fir in Hallasan. In contrast, Jirisan confirmed a long-term trend of declining NDVI in the areas of Korean fir mortality but did not find a significant correlation between the changes in NDVI and environmental variables (LST and precipitation). Further analyses of environmental factors, such as soil moisture, insolation, and wind that have been identified to be related to Korean fir habitats in previous studies should be conducted. This study demonstrated the feasibility of using satellite data for long-term monitoring of Korean fir ecosystems and investigating their changes in conjunction with environmental conditions. Thisstudy provided the potential forsatellite-based monitoring to improve our understanding of the ecology of Korean fir.