• Economic and Environmental Geology
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• v.35 no.5
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• pp.395-406
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• 2002

The sixty natural springs and community wells used as a drinking water in the Daejeon area are mainly located at the parks and the natural green districts. The purpose of this study is to investigate the characteristics of water quality and the contamination of the springs and the wells, and to suggest the management strategy for the springs and wells. For this study, we undertook water quality data from Daejeon City. According to the statistic analysis of water quality data, unacceptable rate as a drinking water was about 28 percent in 1999 and 24.5 percent in 2000, respectively. Major unacceptable factor is coliform, and others are bacteria, yersinia, color, turbidity, Fe and F. The unacceptable rate shows a roughly positive relationship with precipitation, that is, it shows highest rate during a rainy season between June and September. The major contamination source is likely to be the excrement of wild animals around natural springs and wells. Most of springs are vulnerable to the contamination of coliform and bacteria because of short residence time and shallow circulation in subsurface environment. The water samples collected from 31 springs or wells show weak acidic pHs, the electrical conductivity ranging from 63 to 357 $\mu\textrm{S}$/cm, and the hydrochemical types of Na(Ca)-HC0$_3$ and Ca-HC0$_3$. The groundwater samples of low total dissolved solid(TDS) belong to Na(Ca)-HC0$_3$. type, and the groundwater of high total dissolved solid is shifted towards Ca-HC0$_3$ type in the chemical composition. These hydrochemical characteristics indicate that most natural springs is in the early stage of geochemical evolution. The natural springs should be closed during a rainy season, which shows a high contamination rate. We suggest that a protection barrier around the springs should be built to keep wild animals away from the springs.

• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.18-43
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• 2011

The results of study on planting and cultivate of Hong Man-Seon(1643~1715)'s 'Salimkyungjae(The Economy of Forest)' the first summative textbook of agricultural skill of South Korea, are as follows. First, 'Salimkyungjae' suggests that one can enrich oneself, eat fruits in fall, enjoy the shade of trees in summer, and enjoy flowers in spring if one plants tree with 10 year plan with knowledge of ecology. Second, the number of plants had increased continuously from the early Chosun Dynasty to the mid Chosun Dynasty. The 52 plants in the book are classified into 31 trees, 8 shrubs, 3 others, and 10 herbs, and 28 of them are fruit trees. Hence, we can see that the book is for the promotion of welfare. Third, planting(transplantation) is the best on January of the lunar calendar, and the second on February, and fertile soil should be added much. Trees must be planted as deep as once it was planted, and buttressed. It will sprout well if it is planted at the depth of one inch, and planting a cutting should be carried out at the early March with 5 inch and finger-thick branches. Grafting is the best when it begins to sprout. Fruit trees will bear many fruits if they are grafted at the direction of South, and fruits will be greater if the trees' branches are cutting off on January. Especially, January was selected for the best season of planting traditionally. Fourth, flower trees are planted or sowed with manure around January and February of the lunar calendar, and it is recommended to replant them into flowerpots with manure when having flower buds around March and April of the lunar calendar. It would bloom earlier when using water mixed with stable manure, and sulfur smoke can be used in order to change the flower color from red to white. Flowerpots would be placed at half shaded lot with being supported by bricks. Pomegranate, gardenia, camellia and four-season flower should be planted after flowers fallen. When flower trees are beside walls, they need to be rotated frequently since their branches all point toward house. Seeds need to be preserved in a sunny hut, where its entrance and ventilating openings would be at south because it is convenient to manage pots. Fifth, insects hidden at fruit trees would be destroyed by torch smoke when roosters cry on New year's day of the lunar calendar. Insects would be decoyed into straw hanged at dawn of Cheongmyeongday(淸明日). Insects on fruit trees would be controlled using sulfur powder to close up holes or sulfur smoke to fumigate. Particularly, it suggests that utilization of fertile soil would be the best solution for growing health plants and preventing pest.

• The Korean Journal of Malacology
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• v.23 no.2
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• pp.209-216
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• 2007

The ovarian structure and ultrastructural changes in germ cells during oogenesis of the spiny top shell, Batillus cornutus, have been investigated by light and electron microscopic observations. Specimens of the spiny top shell were collected from the subtidal zone of Wando, south coast of Korea. Spiny top shell was dioecious. The ovary was located on the surface of the hepatopancreas in the spiral posterior region. The ovary had greenish color in the gonadal mature season. The ovary comprised many ovarian lobules, and the ovarian lobule consisted of connective mesenchymal tissue and epithelial cells. Oogonium had a large nucleus with nucleolus of high electron density. In previtellogenic oocyte, small yolk granules of low electron density were scattered in the cytoplasm. Oocytes in the initial vitellogenic stage were connected with the ovarian lobule by egg stalk. The result of TEM observations showed that initial vitellogenic oocyte contained well-developed Golgi complex, endoplasmic reticula, tubular mitochondria and numerous yolk granules of various electron densities and sizes. The electron density, size and quantity of yolk granules which were distributed in the active vitellogenic oocyte were increased compared to the previous stage. Thickness of egg envelope in the late active vitellogenic oocyte was approximately 4.4 $[\mu}m$. Cytoplasm of ripe oocyte was filled with proteid yolk globules of high electron density and lipid yolk globules of low electron density. In this stage, the thickness of egg envelope was approximately 6.5 ${\mu}m$.

• Journal of the Korean earth science society
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• v.43 no.5
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• pp.591-603
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• 2022

The color and optical properties of seawater are determined by the interaction between dissolved organic and inorganic substances and plankton contained in it. The Ieodo - Ocean Research Institute (I-ORS), located in the East China Sea, is affected by the low salinity of the Yangtze River in the west and the Tsushima Warm Current in the south. Thus, it is a suitable site for analyzing the fluctuations in circulation and optical properties around the Korean Peninsula. In this study, seawater surrounding the I-ORS was classified according to its optical characteristics using the satellite remote reflectance observed with Moderate Resolution Imaging Spectroradiometer (MODIS)/Aqua and National Aeronautics and Space Administration (NASA) bio-Optical Marine Algorithm Dataset (NOMAD) from January 2016 to December 2020. Additionally, the variation characteristics of optical water types (OWTs) from different seasons were presented. A total of 59,532 satellite match-up data (d ≤ 10 km) collected from seawater surrounding the I-ORS were classified into 23 types using the spectral angle mapper. The OWTs appearing in relatively clear waters surrounding the I-ORS were observed to be greater than 50% of the total. The maximum OWTs frequency in summer and winter was opposite according to season. In particular, the OWTs corresponding to optically clear seawater were primarily present in the summer. However, the same OWTs were lower than overall 1% rate in winter. Considering the OWTs fluctuations in the East China Sea, the I-ORS is inferred to be located in the transition zone of seawater. This study contributes in understanding the optical characteristics of seawater and improving the accuracy of satellite ocean color variables.

• Korean Journal of Food Science and Technology
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• v.12 no.4
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• pp.313-323
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• 1980

The objective of this experiment was to improve the quality and shortening the aging time of Kochujang by adding mixed starter cultures of yeast strains. Kochujangs were mashed during the summer season with mixed starter cultures of Saccharomyces rouxii, Torulopsis versatilis and Torulopsis etchellsii. Enzyme activities and chemical composition of the Kochujang were determined during the period of aging and their organoleptic values were tested. The maximum activities of liquefying amylase and saccharogenic amylase in the Kochujang were obtained during 20 to 60 days and 20 to 30 days after mashing respectively. The acidic protease activity was reached maximum during 20 to 40 days. All enzyme activities were decreased markedly during the final stage of aging period. Among mixed starter cultures tested, mixed culture of T. versatilis and T. etchellsii shows the highest liquefying and saccharogenic amylase activities. Ethyl alcohol contents in 10 days after mashing were highest in the Kochujang with S. rouxii and T. versatilis, followed in order of S. rouxii and T. etchellsii mixture, T. versatilis and T. etchellsii mixture and control without addition of yeast. But the contents in all sample became similar after 20 days with the level of 2.3 to 2.8% and then decreased gradually. The level of reducing sugar contents was markedly increased during the first 10 days, especially in the batches of T. versatilis and T. etchellsii mixture and control. However, the concentration became similar in all samples after 40 days. The contents of amino nitrogen were increased markedly during the first 10 days then slowly up to 90 days. The rate was high in the Kochujang with T. versatilis and T. etchellsii when compared with others. The organoleptic values of all Kochujang made with addition of yeast starter cultures were superior to control, especially in flavor, taste and color. The Kochujang with T. versatilis and T. etchellsii marked the highest value. The data obtained from this experiment suggests that the quality of Kochujang could be improved by using starter culture of suitable yeast strains according to product characteristics and aging time.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.177-182
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• 2007

The objective of this study was to evaluate the genetic relationship between weaning weight (WW) and carcass traits. Carcass traits were eye muscle area(EMA), back fat thickness(BFT), marbling score 1(MS1) in 21 grade scales, marbling score 2(MS2) in 7 grade scales and meat color scores(Mcolor). Parameters were estimated by REML procedure with MTDFREML package. Models included contemporary group as defined by the same year-season-sex at birth, linear covariates of age(days) at weaning, age of dam(days) and age at slaughter(days) as fixed effects and animal random effects for all the traits. Heritability estimates of WW, EMA, BFT, MS1, MS2 and Mcolor were 0.25, 0.20, 0.20, 0.32, 0.32 and 0.22, respectively. Genetic(phenotypic) correlation coefficients of WW with EMA, BFT, MS1, MS2 and Mcolor were 0.75(0.16), 0.18(0.05), －0.41(－0.09), －0.40(0.11) and －0.07(0.05), respectively. Results from this study suggest that single trait selection for weaning weight would lead to progeny population having carcass with large EMA, thick BFT and decreased MS.

• Journal of Aquaculture
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• v.11 no.1
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• pp.49-58
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• 1998

The spawning behavior and early life history of the Korean aucha perch, Coreoperca herzi were studied. The eggs were spawned in a one-layer mass, hanging from the underside of a largy stone and guarded by one male. According to the considerable size difference os eggs in the individual ovaries, it was concluded that they spawns several times within a spawning season of May~June. The ripe eggs were demersal and adhesive, and their diameter were 2.60~3.04mm with several oil globule of 0.10~0.64mm. Hatching in the tank with $19.0{\pm}1.0^{\circ}C.$ in men water temperature started from the 380 hours after fertilization. Newly-hatched larvae were measured 6.45~7.34mm in total length (TL, mean : 6.85mm), and mouth and anus were open. Melanophores were present on the head, around the yolk, and on the dorsal part of the abdominal region. 3 days old larvae were measured 7.00~7.40mm in TL (mean : 7.25mm), and they fed Daphnia sp. and Brachionus plicatilis actively. 6 days old larvae transformed to postlarval stage and they were 7.94~10.10mm in TL (mean : 9.00mm). As yolk sac were nearly absorbed, the caudal notochord flex at 45. Aggregate numbers of all fin rays were completed at over 16.90~19.80mm in TL (30 days after hatching), at which time the larvae reached the juvenile stage. In fifty days old larvae(24.60~27.10mm in TL) were similar in body form, lateral line and color to adult.

• Research in Plant Disease
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• v.23 no.1
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• pp.56-59
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• 2017

During growing season of 2011 to 2013, Sclerotinia rot symptoms consistently have been observed on basil in Yesan-gun, Chungcheongnam-do in Korea. The typical symptom formed initially brownish spot on leaf and stem, and then advancing margins, wilting the whole plant and blighting, eventually died. On the surface of diseased lesions was observed cottony, white, dense mat of mycelial growth, and sclerotia ($30-100{\mu}m$ diameter) formed on stem and leaf. Morphological and cultural characteristic on potato dextrose agar, color of colony was white and colorless chocolate, sclerotium of irregular shape of the oval was black and $5-50{\mu}m$ diameter in size. In pathogenicity test, necrosis and wilt of the inoculated stem were observed in all plants and the pathogen was reisolated from stems. On the basis of mycological characteristics, pathogenicity, and internal transcribed spacer rDNA sequence analysis, this fungus was identified as Sclerotinia sclerotiorum. This is the first report of Sclerotinia rot on basil caused by S. sclerotiorum in Korea.

• Korean Journal of Organic Agriculture
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• v.17 no.1
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• pp.95-109
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• 2009

This study was carried out to determine the effect of application seasons and rates with animal liquid slurry on the rice yield and quality. The treatments were application seasons (autumn, spring) and application rates of animal liquid slurry 80, 100, 120, 140% N levels of based on 11kg N/10a, chemical fertilizer as control plot. Field experiment was conducted at Cheorwon, Gangwon-Do in 2007. The results was as follows; The plant height and tiller's number at the application of spring season were higher than that at the autumn application. In the plot of 140% level at the spring application, the plant height and tillers were higher, and the color of leaf was darker than that of the chemical fertilizer. The plot of 140% level in spring application was increased the lodging damage of rice. Rice yield was reduced at 7%, 13% in the plot of 120%, 140 N/10a slurry level in the spring application compared to the chemical fertilizer, respectively. But rice yield at the autumn application was not significantly difference between chemical fertilizer and plots of liquid manure. The rice quality of the 120 and 140% slurry in spring application was significantly lower than that of chemical fertilizer. Total nitrogen contents and nitrogen uptake in rice plant were higher at the plot of 120, 140%N in the spring than that of chemical fertilizer. To reduce the lodging damage and increase the yield and quality of rice was needed suitable application of liquid manure In spring season.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.3
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• pp.333-340
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• 2014

The purpose of this study was to develop functional lotus root bugak with plasma lipid reduction capacity by controlling the color of batter used for bugak preparation. Lotus root, nearly colorless, was selected to observe color effects. Gardeniae fructus (GF), Opuntia ficus-indica var. saboten (OF), and green tea (GT), which are colored yellow, red, and green, respectively, were used as coloring agents. Fermented glutinous rice was prepared naturally during winter season by placing glutinous rice and water (1:2, w/w) together in a crock pot for 7 days. Coloring materials (10%, w/w) were blended with glue made from fermented glutinous rice flour to prepare the batter. Cooked lotus root was then mixed with a 1.1-fold amount of batter (w/w) and dried at room temperature. Lotus root bugak (LRB) is pan-fried with un-roasted sesame oil, which is traditionally used as frying oil in Korea. Low-density lipoprotein receptor knockout ($LDLr^{-/-}$) mice (n=36) were fed an atherogenic diet (AD) containing various types of LRB (10 g%) for 10 weeks. Plasma triglyceride, total cholesterol, and LDL-C concentrations decreased significantly in mice fed LRB prepared with OF batter (OFB) and GT batter (GTB) (P<0.05). Protein expression levels of fatty acid synthase (FAS) and 3-hydroxyl-3-methylglutaryl coenzyme A reductase (HMGCR) in the OFB and GTB groups were suppressed compared with the LRB group (P<0.05). In accordance with the results on FAS and HMGCR expression, sterol regulatory element binding protein-I and II (SREBP-I and II), which are responsible for the regulation of FAS and HMGCR gene expression, respectively, were down-regulated compared to the LRB group (P<0.05). In conclusion, the plasma lipid reduction activities of OFB and GTB could be mediated through down-regulation of FAS and HMGCR mRNA expression via suppression of regulatory molecules, SREBP-I and II, in $LDLr^{-/-}$ mice.