• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.229-237
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• 2019

This study was conducted to estimate annual reference evapotranspiration (ET₀) for the agro-climatic zones for rice paddy fields in South Korea between 1980 and 2015. The daily ET₀ was estimated by applying the Penman-Monteith method to meteorological data from 61 weather stations provided by Korean Meteorological Administration (KMA). The average of annual ET₀ from 1980 to 2015 was 1334.1±33.89 mm. The ET₀ was the highest at the Southern Coastal Zone due to their higher air temperature and lower relative humidity. The ET₀ had significantly increased with 2.81 mm/yr for the whole zones over 36 years. However, the change rate of it was different among agro-climatic zones. The annual ET₀ highly increased in central zones and eastern coastal zones. In terms of correlation coefficient, the temporal change of the annual ET₀ was closely related to variations of four meteorological factors (i.e., mean, minimum temperatures, sunshine duration, and relative humidity). The results demonstrated that whole Korean agro-climatic zones have been undergoing a significant change in the annual ET₀ for the last 36 years. Understanding the spatial pattern and the long-term variation of the annual ET₀ associated with global warming would be useful to improve crop and water resource managements at each agro-climatic zone of South Korea.

• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.41-48
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• 2009

Natural magnetic fields are attenuated by electrically conductive water. For that reason, marine magnetotelluric surveys have collected data at long periods (1000-100 000 s). The mantle structure has been the main target of seafloor magnetotelluric measurements. To ascertain crustal structure, however, electromagnetic data at shorter periods are important, e.g. in investigations of megathrust earthquake zones, or in natural resource surveys. To investigate of the former, for example, electromagnetic data for periods of less than 1000 s are necessary. Because no suitable ocean bottom electromagnetometer (OBEM) has been available, we have developed a small OBEM and ocean bottom electrometer (OBE) system with a high sample rate, which has an arm-folding mechanism to facilitate assembly and recovering operations. For magnetic observation, we used a fluxgate sensor. Field observations were undertaken to evaluate the field performance of our instruments. All instruments were recovered and their electromagnetic data were obtained. Results of the first experiment show that our system functioned well throughout operations and observations. Results of other field experiments off Tottori support the claim that the electromagnetic data obtained using the new OBEM and OBE system are of sufficient quality for the survey target. These results suggest that this device removes all instrumental obstacles to measurement of electromagnetic fields on the seafloor.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.271-278
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• 2014

Rubus coreanus has been used as a traditional medicine in Asia because of its various pharmacological properties. This study examined the effects of protocatechuic acid (PCA), one of phenolic compounds derived from R. coreanus on the lipid metabolism in high cholesterol diet-induced mice. A total of 30 male C57BL/6 mice were divided into 5 groups with 6 mice in each group as follows: (1) Control mice received normal diet (ND). (2) Mice received high-cholesterol diet (HCD) plus water, 10% sucrose solution and treated daily oral phosphate-buffered-saline (PBS) of equal volumes through gavage. (3) Mice received HCD and treated daily with 25 mg/kg b.w./day of PCA (4) with 50 mg/kg b.w./day or (5) with 10 mg/kg b.w./day of simvastatin via oral gavage for 12 weeks. Body weights were measured weekly for a period of experiment. After treatment, liver, thymus, spleen and kidney were harvested and weighed, and the lipid metabolite profiles (total cholesterol, triglyceride (TG), HDL-cholesterol (HDL-c), LDL-cholesterol (LDL-c) and liver-damaging markers (GOT and GPT) in serum were examined. PCA significantly reduced the total cholesterol, TG, LDL-c level and increased the HDL-c level. PCA administration also significantly reduced the levels of GOT and GPT. These results indicate that the PCA could be used as a functional material for lowering lipid and an adjuvant for the treatment of hyperlipemia.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.101-107
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• 2010

This study was carried out to provide basic data for efficient park management by analysing visitors' satisfaction factors and estimated regression model through questionnaire survey method at Taeanhaean National Park in Korea. Performance(satisfaction) variables as 'touting', 'illegal merchant', 'noise', 'indiscreet use' and 'collection of natural plants or animals', and Importance variables as 'littering problem', 'water pollution act', 'careless cooking' and 'exorbitant pay' were relatively high score. It was clarified that the 'souvenir & special product', 'lack of use program' 'lack of public facility', 'lack of information facility', and 'lack of commercial facility' were 'concentrate here' ones by the Importance-Performance analysis. 'Facility management', 'Use management' and 'Resource management' factors were found out by Factor Analysis and the 'Facility management' was the biggest factor accounting for 32.6% of all. In the estimated model by Multiple Regression Analysis, 'lack of employee's guidance or kindness', 'lack of convenience facility', 'noise', 'lack of facilities to stay' and 'charge of user fee, parking fee' were the variables to impact visitors' satisfaction and to need concentrated management. These results were unique characteristics of marine national park and then the different management strategy and policy from mountain national park were necessary.

• Journal of Korean Society of societal Security
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• v.4 no.2
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• pp.65-72
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• 2011

This study was carried out to investigate the cause of acidification of rainwater and to evaluate the possibility of alternative water resource in Saemangeum. The rainwater were collected in the kwangwhal-myun, Saemangeum from March to September, 2009. The collected 7 samples were analyzed with pH meter, IC (ion chromatography) and ICP (inductively coupled plasma) about the pH and the major ions ($SO{_4}^{2-}$, $NO_3{^-}$, $Cl^-$, $Ca^{2+}$, $K^+$, $NH^{4+}$, $Na^+$ and $Mg^{2+}$) of rainwater. The order of the major anion concentration and the acidification contribution in the rainwater was $SO{_4}^{2-}$>$NO_3{^-}$>$Cl^-$, and that of the major cation was $Ca^{2+}$>$K^+$>$NH_4{^+}$>$Na^+$>$Mg^{2+}$. In the initial rainwater, the major ions concentration were higher than the middle period. pH of the rainwater was the lowest at May, but similar to the results of the others. And pH of the rainwater were significant correlation with $SO{_4}^{2-}$ and $Cl^-$ in Saemangeum. From this results, the rainwater was slight acidic, and $SO{_4}^{2-}$ was the main factor contributed to the rainwater acidification in Saemangeum.

• Korean Journal of Medicinal Crop Science
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• v.18 no.6
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• pp.409-415
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• 2010

In this study, the bioactivities of ethanol (EELS) and water extract (WELS) from the leaf of Lythrum salicaria L. were investigated. In the anti-cancer activity, the growths of both human prostate cancer (DU145) and human colonic carcinoma cell (HT29) were inhibited up 60% by adding 10 mg/$m{\ell}$ of EELS. Anti-inflammatory activity of EELS and WELS have been evaluated on lipopolysaccharide (LPS) induced release of nitric oxide (NO) by the macrophage RAW 264.7 cells. EELS and WELS inhibited inflammatory by 57.3 and 46.9% in 10 mg/$m{\ell}$, respectively. In the anti-oxidative activity, $IC_{50}$ of DPPH radical scavenging activity was respectively 60.71 and $92.90\;{\mu}g/m{\ell}$ by EELS and WELS. In the anti-diabetic activity, $IC_{50}$ of ${\alpha}$-amylase inhibitory activity of EELS and WELS were respectively 5,250 and $5,020\;{\mu}g/m{\ell}$. $IC_{50}$ of ${\alpha}$-glucosidase inhibitory activity was 7.96 and $68.41\;{\mu}g/m{\ell}$ by EELS and WELS. In the anti-obesity, $IC_{50}$ of lipase inhibitory activity was 880 and $9,840\;{\mu}g/m{\ell}$ by EELS and WELS. Finally, EELS and WELS exhibited anti-oxidative, anti-inflammatory, anti-diabetic activity and anti-obesity. It suggests that Lythrum salicaria L. could be potentially used as a resource of bioactive materials for health functional foods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.2
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• pp.141-148
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• 2011

This feeding experiment was conducted to investigate the effects of dietary inclusion of various additives on growth performance, hematological parameters, fatty acid composition, gene expression and histopathological changes in juvenile olive flounder (Paralichthys olivaceus). Eleven isonitrogenous (49% crude protein) and isolipidic (10% crude lipid) experimental diets were formulated: no additives (Con); 5% kelp meal (Ke); 10% krill meal (Kr); 1% garlic powder (Ga); 1% citrus meal (Ci); 3% onion powder (On); 1% ginger powder (Gi); 1% mugwort powder (Mu); 1% licorice powder (Li); 1% wasabi powder (Wa); and a mixture (Mix) of these additives. Three replicate groups of juvenile flounder (average weight of 8.5 g) were fed one of the experimental diets to visual satiety twice a day for 15 weeks. The dietary inclusion of additives did not affect survival, weight gain, specific growth rate feed efficiency, daily feed intake, daily protein intake, protein efficiency ratio, hepatosomatic index and visceralsomatic index of the fish. Plasma triglyceride levels were significantly lower in fish fed the Ke, Ga, On, Gi, Mu, Li, and Mix diets than in fish fed the control diet. Plasma glucose, glutamic oxaloacetic transaminase and total cholesterol did not differ among dietary treatments. No significant difference was observed in fatty acid composition and lipid content of the dorsal muscle in fish fed the experimental diets. Myosin gene expression did not differ significantly among treatments after 5 weeks but was significantly lower in fish fed the Kr, Ci, Li, and Mix diets than in control group after 15 weeks. Histopathological analysis showed mild gill hyperplasia and mild necrosis of liver parenchymal cells in several individuals of each experimental group. These conditions were also observed in the control group and were not thought to be related to the inclusion of feed additives. The present findings indicate that the dietary inclusion of additives did not affect growth performance, fatty acid composition, gene expression, and histopathological changes in juvenile flounder. However, plasma triglyceride content may be reduced by supplementation with 5% kelp meal, 3% onion powder, 1% garlic powder, 1% ginger powder, 1% mugwort powder, and the additive mixture.

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.552-556
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• 1998

In this study, the quality stability of a kind of natural seasoning material, the mixture of enzyme treated mackerel meat and Laminaria powder during the storage was investigated by measuring the TBA(thiobarbituric acid)value, extend of browning, changes in amino nitrogen and chlorophyll a, and fatty acid composition, and the results of sensory evaluation. Addition of sodium alginates (0.08%) and calcium carbonate (0.02%) seemed effective as a binder to yield clarity of the hot water extract of the product. In results, the mixture of Laminaria powder and the enzyme treated mackerel meat added with 0.08% sodium alginate and 0.02% calcium carbonate was more stable in overall quality than the other cases of preparation. And the taste of the mixture could favorably compete with that of dried anchovy extracts.

• Journal of Korea Foresty Energy
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• v.23 no.2
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• pp.9-20
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• 2004

Growth and nutrients of Xinjiang poplar (Populus alba var. pyramidalis) seedlings treated with fertilizers and soil amendments were examined in nursery and windbreak at Dengkou after 6 months of treatments in Inner Mongolia, China. Soil water content was $10\%$ higher than that at most soils in desert. Height and diameter growth and foliar nitrogen (N) concentration were higher at N and nitrogen plus phosphorus (N+P) fertilizer treatments than other treatments. However, there were no differences in foliar P concentration among treatments in windbreak and foliar P concentration was higher at control than at other treatments in nursery. Yuho treatment increased height and diameter growth. Nitrogen appeared an influenciug factor for early growth of Xinjiang poplar, and P had a minor affect on growth. More long-time studies were needed to elucidate the effects of fertilizers and soil amendments on growth and nutrients of Xinjiang poplar.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.404-417
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• 2016

The purpose of this study is to examine the extent to which the deterioration in strength of high strength concrete of 60MPa replaced by a large amount of recycled coarse aggregates (more than 60% to 100% of replacement ratio) could be recovered with steel fiber reinforcement through material compressive strength test and shear failure test on short and middle beams and then to offer useful data for aggregate supply system of a sustainable resource circulation type. This study first examined the results of previous related tests. The results of the material compressive strength tests confirmed that when using a combination of steel fiber reinforcements of volumn ratio 0.75% and high quality recycled coarse aggregates with an water absorption rate within 2.0%, the strength characteristics of high strength concrete of 60MPa level were not only restored to the strength level of concrete made with natural aggregates, but also showed superior ductility. And the shear failure tests on short and middle beams using recycled coarse aggregates more than 60% with shear span to depth ratio (a/d) of 2 and 4 controlled by shear forces mainly confirmed that effects of superior shear strength increase and ductile behavior characteristics were showed by steel fiber reinforcements.