• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.503-514
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• 2020

Climate change leads to changes in phenological response and movement of plant habitats. Korea's evergreen broad-leaved forest has widened its distribution area compared for the past 20 years, and the range of its native habitats is moving northward. We analyzed climate indices such as the warmth index, the cold index, the lowest temperature in the coldest month, and the annual average temperature, which are closely related to vegetation distribution, to predict the change in the native habitat of Lauraceae evergreen broad-leaved trees. We also analyzed the change and spatial distribution to identify the habitat climate characteristics of 8 species of Lauraceae evergreen broad-leaved trees distributed in the warm temperate zone in Korea. Moreover, we predicted the natural habitat change in the 21st century according to the climate change scenario (RCP 4.5/8.5), applying the MaxEnt species distribution model. The monthly average climate index of the 8 species of Lauraceae evergreen broad-leaved trees was 116.9±10.8℃ for the temperate index, the cold index 3.9±3.8℃, 1495.7±455.4mm for the annual precipitation, 11.7±3.5 for the humidity index, 14.4±1.1℃ for the annual average temperature, and 1.0±2.1℃ for the lowest temperature of winter. Based on the climate change scenario RCP 4.5, the distribution of the Lauraceae evergreen broad-leaved trees was analyzed to expand to islands of Jeollanam-do and Gyeongsangnam-do, adjacent areas of the west and south coasts, and Goseong, Gangwon-do on the east coast. In the case of the distribution based on the climate change scenario RCP 8.5, it was analyzed that the distribution would expand to all of Jeollanam-do and Gyeongsangnam-do, and most regions except for some parts of Jeollabuk-do, Chungcheongnam-do, Gyeongsangbuk-do, and the capital region. For the conservation of Lauraceae evergreen broad-leaved trees to prepare for climate change, it is necessary to establish standards for conservation plans such as in-situ and ex-situ conservation and analyze various physical and chemical characteristics of native habitats. Moreover, it is necessary to preemptively detect changes such as distribution, migration, and decline of Lauraceae evergreen broad-leaved trees following climate change based on phenological response data based on climate indicators and establish conservation management plans.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.1
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• pp.107-123
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• 2018

The global impact of climate change on agriculture is now increasing. The purpose of this study was to investigate the effect of climate change on livestock productivity. The variables that have the greatest influence on climate change factors were examined through previous studies and expert surveys. We also used the actual productivity data of livestock farmers to investigate the relationship with climate change. In order to evaluate the climate for changes in livestock productivity, national representative data (such as bullocks, dairy, pigs, laying hens, and broilers) were surveyed in Korea. Also, to select and classify evaluation indexes, we selected climate change factor variables as prior studies and studied the weighting factor of climate variable factors. In this study, the researchers of industry, academia, and farmers in the livestock sector conducted questionnaires on the indicators of vulnerability to climate change using experts, and then weighed the selected indicators using the hierarchical analysis process (AHP). In order to verify the validity of the evaluation index, was examined using domestic climate data (temperature, precipitation, humidity, etc.). Correlation and regression analysis were performed. The empirical relationship between climate change and livestock productivity was examined through this study. As a result, we used data with high reliability of statistical analysis and found that there are significant variables.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.353-365
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• 2023

The effects of climate change on green infrastructure and environmental media remain uncertain and context-specific despite numerous climate projections globally. In this study, the extreme weather conditions in seven major cities in South Korea were characterized through statistical analysis of 20-year daily meteorological data extracted fro m the Korea Meteorological Administration (KMA). Additionally, the impacts of extreme weather on Nature-based Solutions (NbS) were determined through a comprehensive review. The results of the statistical analysis and comprehensive review revealed the studied cities are potentially vulnerable to varying extreme weather conditions, depending on geographic location, surface imperviousness, and local weather patterns. Temperature extremes were seen as potential threats to the resilience of NbS in Seoul, as both the highest maximum and lowest minimum temperatures were observed in the mentioned city. Moreover, extreme values for precipitation and maximum wind speed were observed in cities from the southern part of South Korea, particularly Busan, Ulsan, and Jeju. It was also found that extremely low temperatures induce the most impact on the resilience of NbS and environmental media. Extremely cold conditions were identified to reduce the pollutant removal efficiency of biochar, sand, gravel, and woodchip, as well as the nutrient uptake capabilities of constructed wetlands (CWs). In response to the negative impacts of extreme weather on the effectiveness of NbS, several adaptation strategies, such as the addition of shading and insulation systems, were also identified in this study. The results of this study are seen as beneficial to improving the resilience of NbS in South Korea and other locations with similar climate characteristics.

• Analytical Science and Technology
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• v.28 no.3
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• pp.182-186
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• 2015

In this study, the porous CuO/MnO₂ catalyst was prepared through the co-precipitation process from an aqueous solution of potassium permanganate (KMnO₄), manganese(II) acetate (Mn(CH₃COO)₂·4H₂O) and copper(II) acetate (Cu(CH₃COO)₂·H₂O). The phase change in MnO₂ was analyzed according to the reaction molar ratio of KMnO₄ to Mn(CH₃COO)₂. The reaction mole ratio of KMnO₄ to Mn(CH₃COO)₂·4H₂O was varied at 0.3:1, 0.6:1, and 1:1. The aqueous solution of Cu(CH₃COO)₂ was injected into a mixed solution of KMnO₄ and Mn(CH₃COO)₂ to 10~75 wt% relative to MnO₂. The Cu ion co-precipitates as CuO with MnO₂ in a highly dispersed state on MnO₂. The physicochemical property of the prepared CuO/MnO₂ was analyzed by using the TGA, DSC, XRD, SEM, and BET. The different phase types of MnO₂ were prepared according to the reaction mole ratio of KMnO₄ to Mn(CH₃COO)₂·4H₂O. The results confirmed that the porous CuO/MnO₂ catalyst with γ-phase MnO₂ was produced in the reaction mole ratio of KMnO₄ to Mn(CH₃COO)₂ as 0.6:1 at room temperature.

• The Journal of Engineering Geology
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• v.16 no.1 s.47
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• pp.69-83
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• 2006

This study aims to evaluate a complex groundwater flow system around the underground oil storage caverns using the concept of hydraulic compartment. For the hydrogeological analysis, the hydraulic testing data, the evolution of groundwater levels in 28 surface monitoring boreholes and pressure variation of 95 horizontal and 63 vertical water curtain holes in the caverns were utilized. At the cavern level, the Hydraulic Conductor Domains(fracture zones) are characterized one local major fracture zone(NE-1)and two local fracture zones between the FZ-1 and FZ-2 fracture zones. The Hydraulic Rock Domain(rock mass) is divided into four compartments by the above local fracture zones. Two Hydraulic Rock Domains(A, B) around the FZ-2 zone have a relatively high initial groundwater pressures up to $15kg/cm^2$ and the differences between the upper and lower groundwater levels, measured from the monitoring holes equipped with double completion, are in the range of 10 and 40 m throughout the construction stage, indicating relatively good hydraulic connection between the near surface and bedrock groundwater systems. On the other hand, two Hydraulic Rock Domains(C, D) adjacent to the FZ-1, the groundwater levels in the upper and lower zones are shown a great difference in the maximum of 120 m and the high water levels in the upper groundwater system were not varied during the construction stage. This might be resulted from the very low hydraulic conductivity$(7.2X10^{-10}m/sec)$ in the zone, six times lower than that of Domain C, D. Groundwater recharge rates obtained from the numerical modeling are 2% of the annual mean precipitation(1,356mm/year) for 20 years.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.1-8
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• 1997

A complement system-activating (anti-complementary) polysaccharide was purified from the hot water extract of young stems of Cinnamomum cassia Blume. Crude polysaccharide fraction (CC-1) was prepared from the hot water extract of the young stems followed by methanol-reflux, precipitation with ethanol, dialysis, and lyophilization. The anti-complementary activity of CC-1 was decreased greatly by periodate oxidation, but was not changed by pronase digestion. These suggest that carbohydrate moiety may be related to the activation of complement system. According to its ionic strength CC-1 was fractionated first using cetavlon to give 4 fractions, CC-2, 3, 4 and 5. Among them CC-2 fraction was found to retain the highest activity and yield. CC-2 was separated to an unabsorbed neutral sugar portion (CC-2-I) and seven absorbed acidic sugar fractions $(CC-2-II{\rightarrow}CC-2-VIII)$ on DEAE-Toyopearl 650C (Cl-). CC-2-III showing higher anti-complementary activity and yield than those of other fractions, was further purified on the gel permeation of Sephadex G-100 and Sepharose CL-6B to CC-2-IIIa-3. CC-2-IIIa-3 was determined to have a homogeneity hy GPC (Sepharose CL-6B) and HPLC. Gel chromatography using standard dextrans gave a value of $2.4{\times}10^5$ for the molecular weight. The purified polysaccharide, CC-2-IIIa-3 consisted of arabinose, xylose, glucose, galactose, galacturonic acid and glucuronic acid in a molar ratio of 5.56 : 3.77 : 1.87 : 1.00 : 5.12 : 3.13 and contained no nitrogen.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.793-798
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• 2006

We investigated the effects on the cytotoxicity against several cancer cells of the hydrolysis and molecular weight fractionation of crude laminaran from E. bicyclis, a brown seaweed collected from Uleung island in Korea, was extracted with boiling water and then crude laminaran was prepared by ethanol precipitation of extract obtained after elimination of calcium alginate by calcium chloride. Crude laminaran was hydrolyzed by enzyme (Econase CE), acid (0.1 N HCl) and autoclaving ($121^{\circ}C$, 180 min), and the molecular weight fractions by ultrafiltration to generate molecular weight fractions. Total sugar and sulfate contents of hydrolyzed laminaran were 72.3 and 3.5% (enzyme hydrolysate), 68.5 and 3.0% (acid hydrolysate), 70.2 and 3.2% (autoclaved), and monosaccharides of which consisted of glucose (74.7-78.5%), mannose (9.9-11.5%), galactose (8.5-9.6%) and fucose (3.1-4.5%), respectively. When the cytotoxicity of hydrolyzed laminaran on SNU-1, HeLa and SW cells was evaluated by MTT assay, growth-inhibitory activity of the enzyme hydrolysate against cancer cells was higher than that of acid hydrolysate or autoclaved laminaran. Furthermore, the fraction at a molecular weight range of 10 to 50 kDa revealed higher anti-proliferative activities. The $IC_{50}$ values of 10-50 kDa fraction at a molecular weight range of 10 to 50 kDa revealed higher anti-proliferative activities. The $IC_{50}$ values of 10-50 kDa fractions on SNU-1, HeLa and SW cells were 60.4, 58.6 and 53.9 ${\mu}g/mL$ for enzymatic hydrolysate, 75.6, 73.5 and 77.4 ${\mu}g/mL$ for acid hydrolysate, and 61.7, 68.2 and 60.8 ${\mu}g/mL$ for autoclaved, respectively.

• Korean Journal of Microbiology
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• v.47 no.2
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• pp.117-123
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• 2011

The purpose of this study was to evaluate and compare different elution and concentration methods for optimization of human rotavirus (HRV) detection method using real-time RT-PCR and cell culture techniques. The leafy vegetable samples (lettuce, Chinese cabbage) were artificially inoculated with HRV. Viruses were extracted from the vegetables by two different elution buffers, buffer A (100 mM Tris-HCl, 50 mM glycine, 3% beef extract, pH 9.5) and buffer B (250 mM Threonine, 300 mM NaCl, pH 9.5), and the extracted viruses were concentrated by filtration and PEG precipitation sequentially. To determine infectivity of the viruses, the viruses recovered from the samples were infected to the MA-104 cells, and integrated cell culture real-time RT-PCR was performed at 1, 48, 72, 96, 120, 144, 168 h post-infection (p.i.). The elution buffer A was more efficient in extracting the virus from the produce samples tested than the buffer B, 29.54% and 18.32% of recoveries, respectively. The sensitivity of real-time RT-PCR method was markedly improved when the virus was concentrated by the filtration method. When the viruses were eluted and concentrated by buffer A and filtration, respectively, the average recovery rate was approximately 51.89%. When the viruses recovered from samples were infected to MA-104 cell, infectious HRV was detected within 48 h p.i. by ICC/real-time RT-PCR, whereas cytopathic effects were not observed until 72 h p.i. The optimized detection method evaluated in this study could be useful for rapid and reliable detection of HRV in fresh produce products and applied for detection of other food-borne viruses.

• Korean Journal of Remote Sensing
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• v.34 no.3
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• pp.519-533
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• 2018

The sensible heat flux (SHF)and latent heat flux (LHF) over Korean Peninsula ocean during recent 4 years were calculated using Coupled Ocean-Atmosphere Response Experiment (COARE) 3.5 bulk algorithm and satellite-based atmospheric-ocean variables. Among the four input variables (10-m wind speed; U, sea surface temperature; $T_s$, air temperature; $T_a$, and air humidity; $Q_a$) required for heat flux calculation, Ta and $Q_a$, which are not observed directly by satellites, were estimated from empirical relations developed using satellite-based columnar atmospheric water vapor (W) and $T_s$. The estimated satellite-based $T_a$ and $Q_a$ show high correlation coefficients above 0.96 with the buoy observations. The temporal and spatial variability of monthly ocean heat fluxes were analyzed for the Korean Peninsula ocean. The SHF showed low values of $20W/m^2$ over the entire areas from March to August. Particularly, in July, SHF from the atmosphere to the ocean, which is less than $0W/m^2$, has been shown in some areas. The SHF gradually increased from September and reached the maximum value in December. Similarly, The LHF showed low values of $40W/m^2$ from April to July, but it increased rapidly from autumn and was highest in December. The analysis of monthly characteristics of the meteorological variables affecting the heat fluxes revealed that the variation in differences of temperature and humidity between air and sea modulate the SHF and LHF, respectively. In addition, as the sensitivity of SHF and LHF to U increase in winter, it contributed to the highest values of ocean heat fluxes in this season.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.8
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• pp.950-955
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• 2007

Non-point source control system which had been designed only for oil-water separation in the fields of oil refinery and garage was upgraded in this research for the removal of runoff pollutants in impervious urban area. Pollutants including oil from driveway and bridge were eliminated by two types of pathway in the system. One is the coalescence mechanism that the oil droplets in the runoff come into contact with each other in the spiral buoyant media surface and form larger coalesced droplets of oil that are carried upstream to the oil layer. The other is the precipitation that solids in runoff were settled by gravity in the system. In this research, coalescing characteristics of oil and water separation were investigated through image analyses, and efficiencies of the non-point source control system were evaluated using dust in driveway and waste engine oil. Media made of high density and high molecular weight polyethylene was indeterminate helical shape and had sleek surface by analysing SEM photographs and BET. Surface area and specific gravity of media which were measured directly were 1,428 $mm^2$ and 45.3 $kg/m^3$ respectively. From the image analyses of the oil droplets photographs which were taken by using microscope, it was proved clearly that the coalescence was the main pathway in the removal of oil from the runoff. Finally, the performances of the non-point source control system filled up with the media were suspended solid $86.6\sim95.2%$, $COD_{Cr}$, $87.3\sim95.4%$, n-Hexane extractable materials $71.8\sim94.8%$ respectively.