• Journal of the Korean Society of Groundwater Environment
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• v.1 no.2
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• pp.100-104
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• 1994

The rock matrix diffusion provides a retarding mechanism for sorbing and especially non-sorbing radionuclides. It has to be verified not only theoretically and experimentally but also from natural phenomena, before the mechanism can be incorporated fully into transport codes. The natural analogue studies, such as the concentration variation of radionuclides in profiles perpendicular to fluid-conducting fractures and to intrusive contact zones, have been believed to provide a validation. In thermal alteration zones of Naeduckri granite intruded by a pegmatite, large alkali and alkaline earth elements such as K, Rb, Sr, and Ba were moderately migrated during thermal alteration. Li, V. and Nb were also migrated about 9cm in width from the contact between the granite and the pegmatite. The concentration variation of these elements in thermally altered zones seems to be resulted from the local migration due to the re-equilibration among the elements released from the breakdown of primary minerals in the granite. Most of these natural analogue studies simply show only the concentration variation of elements without detailed informations on the diffusion time and other important data fir interpreting the behaviour of radionuclides, because of the absence of appropriate minerals for age data. Despite this problem, natural analogue studies will be needed for transport models of radionuclides in safety assessment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.6
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• pp.536-542
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• 1984

Fish eggs and larvae in the western waters of Korea are surveyed during the periods from February to August in 1982. Six species of eggs and forty-two species of larvae are occurred in the survey area. The dominant species occurred during the study periods are Ammodytes personatus, Enedrias sp., Engraulis japonica, Callionymus sp., Gobiidae, etc. Major spawning month and ground of each species are estimated from the data, i.e., occurrence month and abundance of eggs and larvae by survey month and area, as well as the optimum water temperature and salinity for spawning.

• Journal of the Korean earth science society
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• v.30 no.3
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• pp.267-281
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• 2009

Cretaceous intrusive and extrusive rocks are widely distributed in the southern part of the Korean peninsula, possibly the result of intensive magmatism which occurred in response to subduction of the Pacific plate beneath the northeastern part of the Eurasian plate. Geochemical and petrological study on the Cretaceous granitic rocks of the Yeosu area were carried out in order to constrain the petrogenesis of the granitic rocks and to establish the paleotectonic environment of the southwestern part of the Korean peninsula. Igneous rocks of the Yeosu area consist of diorite, hornblende biotite pite and micrographic granite. Chondrite normalized REE patterns show generally enriched in LREE ($(La/Lu)^{cN}$=4.2-13.3). Diorites show flat to slight negative Eu anomalies while micrographic granites have strong negative Eu anomalies. The ${\Sigma}REE$ of the granites are 76.2-235 ppm, which corresponds to the range of the continental margin granite. Whole rock chemical data of the granitic rocks from the Yeosu area indicate that the rocks have characteristics of calc-alkaline series in the subalkaline field. On the A/NK vs. A/CNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type and volcanic arc granite (VAG). Interpretations of the chemical characteristics of the granitic rocks favor their emplacement in a compressional tectonic regime at continental margin during the subduction of Pacific plate.

• KOREAN POULTRY JOURNAL
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• v.5 no.10 s.48
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• pp.57-72
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• 1973

1. 육추율, 육성율, 성계생존율 육추율은 99.9$\%$로서 1회 98.5$\%$, 2회 99.2$\%$, 3회 99.8$\%$, 4회 98.3$\%$, 5회 98.7$\%$, 6회 99.7$\%$와 비슷하였다. 육성율은 평균 98.8$\%$로서 1회 97.5$\%$, 2회 97.2$\%$, 3회 96.6$\%$, 4회 97.9$\%$와는 큰차가 없었고 5회 89.7$\%$ 6회 87.1$\%$ 보다는 약 12$\%$가 높게 나타났다. 이는 MD 백신접종 때문인 것으로 생각되며 성계생존율은 평균 86.3$\%$로서 87.3$\%$ 보다는 약 1$\%$낮았고 1회 80.3$\%$ 2회 84.8$\%$보다는 약 4.6$\%$ 높고 3회 71.8$\%$, 5회 71.4$\%$, 6회 75.3$\%$에 비하면 19$\%$나 높았다. 2. 성성숙일령 전체평균은 157.3일로 가장 빠른 구는 4구의 146일이고 가장 늦은 구는 10구와 17구의 161일이였다. 3. 산란율, 산란지수 산란율은 평균 62.0$\%$이고 가장 높은 구는 15구의 68.9$\%$ 이였다. 산란지수는 평균 205.1개로 1회 190.8, 2회 198.3, 3회 184.2, 5회 186.5, 6회 189.7개에 비하여 높고 4회때와 근사하였다. 4. 사료요구율 전체평균 3.23으로 1회 3.54, 2회 3.1과는 근사하나 3회 2.98, 4회 2.87 5회 2.83에 비하여 낮은 것은 사양표준은 작년도와 같으나 원료사료 특히 단백질 사료의 품질저하에 원인이 있었다. 5. 난평균 중량 검정계군 전체의 평균난중은 61.2g으로 최상위구는 64.70g, 최하위구는 58.3g이였다. 6. 체중 검정계의 전체의 평균제중은 300일령 1925.1g, 500일 1938.4g이며 유색품종은 300일령 1986.7g, 500일령 1948.4g이였다. 7. 사료섭취량 사료섭취량 평균은 1일수당 육추기 32.1g 육성기 73.0g 산란기 115.6g이었다. 8. 경제성 총 수입은 7,269,072.34으로 전체수입의 85$\%$가 계란수입이고 15$\%$는 폐계수입이었다. 지출은 5049,690으로 전체 지출의 99.95$\%$가 사료비 0.05$\%$가 초생추대이었다. 9. 후기 검정수수미달은 참고구로 처리하였고 축산시험장과 대천종축장에서는 당초부터 참고구로 출품하였다. 대신의 개리슨, 신기의 하바드 코메트는 수정율이 낮아서 검정수수가 미달되었으며 영국의 Sykes International Co. 에서 출품한 Sykes Tinted(WL$\times$RIR BX)는 출품회사에서 직접 종란을 항공편에 보내 인수 부화하여 검정하였다. 7회 부터는 초생추에 MD(뎁타백) 백신을 하여 초산전후에 폐사율이 적었으며 72년 11월부터 국산어분에 의한 염도의 과다에 의하여 약 2주일 설사를 하여 상당히 스트레스를 받은 바 있었다.

• Korean Journal of Poultry Science
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• v.50 no.3
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• pp.161-169
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• 2023

The present study aimed to investigate the effect of Allium hookeri (AH) root on growth performance, serum antioxidant enzyme activity, cecal short-chain fatty acid profiles, and tight junction-related gene expression of broiler chickens. On day 10, 96 birds were allocated to one of two dietary treatments with 6 replicate cages, and 8 birds per cage in a randomized complete block design. The experimental diets consisted of a corn-soybean meal-based control diet and a diet supplemented with 0.3% AH root powder at the expense of the corn in the control diet. The experimental diets were formulated to meet or exceed the nutrients requirements of broilers recommended by Aviagen for each phase (from day 10 to 21 and from day 21 to 28). On day 28, a bird representing the median body weight in each cage was selected, and then blood, cecal digesta, and jejunum tissue samples were collected. No significant differences were observed in body weight gain and feed intake among dietary treatments. However, birds fed the diet containing AH showed a greater gain-to-feed ratio compared to the control group at 21 days of age and throughout the entire experimental period (P<0.05). Serum antioxidant enzyme activity, cecal short-chain fatty acid profiles, and tight junction-related gene expression were not affected by the dietary AH supplementation. Based on the results of the present study, dietary AH supplementation may improve the gain-to-feed ratio, but not gut health markers in broiler chickens from day 10 to 28.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.129-136
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• 2000

Differentiation and development of the digestive organ of the black sea bream, AcanHepagus schlegeli were studied by means of histological methods. The hatched lawn if TL(total length) $2.0 mm (n=10)$ had a yolk sac of $1,000{\times}590 {\mu}m$ and simple straight digestive tract, which was composed of cuboidal epithelium. In the pre-larval stage of TL $3.5 mm$, digestive tract could be distinguished into esophagus, stomach and intestine, and the exocrine glands were appeared in the pancreas. In this stage mucosal folds, eosinophilic granule cells and brush border were observed in the posterior intestine. Yolky materials were completely absorbed and the brush border was recognized in the free surface of anterior intestine in TL $3.7 mm$. In the stomach mucosal folds began to appear from TL $4.0 mm$. In this time the zymogen granules were recognized in the cytoplasm of pancreatic exocrine cells. In the post-larval stage ranged from $4.5 to 5.0 mm$ in TL, hepatic cords started to develop, and the mucous secretory cells of PAS positivewere observed at esophagus and intestine. In the post-larval stage ranged from $6.3 to 7.0 mm$ in TL, histological layer of esophagus and intestine could be distinguished into serous membrane, muscular layer, submucosal layer and mucosal layer. From over TL $9.0 mm$, stomach could be distinguished into cardiac, fundic and pyloric portion, and the gastric gland began to appear at mucosal fold of fundic stomach. In the juvenile stage ranged from $10.0 to 11.0 mm$ in TL, histological structures of esophagus and intestine were similar to those of adult. From over TL $15.0 mm$, histological structures of stomach were similar to those of adult. Structural and functional digestive organ of black sea bream was present from the juvenile stage ranged from $15.0 to 17.0 mm$ in TL.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.61-72
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• 2004

The soil samples were collected from the paddy field near the mine tailing dumps in the abandoned Duckum mine in Korea. In the laboratory, the soil solution was extracted from the soil using centrifuge, and analysed for the chemical composition. Physical and chemical soil properties were also analysed. Kaolinite is the main clay minerals in the paddy soil and the CEC value is therefore relatively low. Nearly all soil samples show enrichment in their trace elemental concentrations(Cd, Cu, Pb and Zn) compared with natural background level. Some soil samples exceed the soil remediation intervention values for Cd, Pb and Zn and target value for Cu, when compared with Dutch standard, whereas As, Ni and Cr are in normal range. Lead concentrations in some samples near the mine tailing dumps also exceed the standard for remediation act for agricultural area set by Korean soil conservation law. The trace elemental concentrations are higher in the paddy soil nearer the mine tailing dumps and lower for the samples from distance. Similar trend with distance is found for the soil solution chemistry but the decrease with distance from the mine tailing dumps are sharper than the changes in soil chemistry. Cadmium, Cu and Pb concentrations in the soil solution are very low, ranging from a tenth and hundredths to a maximum of several mg/l, whereas their concentrations in soils are highly enriched for natural background. Most of the trace elements are thought to be either removed by reduced iron sulphides or iron oxides, depending on the redox changes. Geochemical equilibrium modelling indicate the presence of solubility controlling solid phases for Cd and Pb, whereas Zn and Cu might have been controlled by adsorption/desorption processes. Although pollutants migration through solution phase are thought to be limited by adsorption onto various Fe, Mn solid phases, the pollutants exist as easily releasable fractions such as exchangeable site. In this case, the paddy soil would act as pollutant pool, which will supply to plants in situ. whenever the geochemical conditions favour.

• Korean Journal of Environmental Biology
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• v.22
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• pp.1-10
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• 2004

We conducted three experiments to estimate the toxicity of POPs (persistent organic pollutants) on two copepod species (Acartia erythraea and A. omorii) and Artemia sp.; (1) 48 h-LC$_{50}$ of A. omorii with the five PAHs [polycyelic aromatic hydrocarbons anthracene, benzo〔a〕pyrene, fluoranthene, phenanthrene, pyrene〕 which were often detected in the Gwangyang Bay, (2) toxicity of benzo〔a〕pyrene and TBT on Artemia in different temperatures (1$0^{\circ}C$, 15$^{\circ}C$, 2$0^{\circ}C$), (3) effects of benzo〔a〕pyrene and TBT on egg Production rate, hatching rate and fecal Pellet Production of two copepod species (A. erythraea and A. omorii) fed on Heterocapsa triquetra (dinoflagellate) exposed in benzo〔a〕pyrene. Toxic chemicals which were most effective to A. omorii were flueranthene (48 h-LC$_{50}$ 19.20 $\mu\textrm{g}$ L$^{-1}$ ) and benzo〔a〕pyrene (48 h-LC$_{50}$ 29.89 $\mu\textrm{g}$ L$^{-1}$ ). The toxi- city of chemicals to Artemia increased when temperature increased. The toxicity of TBT was about 100 times higher than that of benzo〔a〕pyrene at 15$^{\circ}C$. Food materials (Heterocapsa triquetra) exposed in benzo〔a〕pyrene, affected negatively the rate of egg production, hatching rate and the fecal pellet production of the copepods at the high concentration. It is suggested that an increase in the concentration of benzo〔a〕pyrene might offset the production of copepods in marine ecosystems. This study suggests that copepods may be used as n indicator for early warning of the risk of POPs in marine ecosystems.

• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.77-85
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• 2012

This study was to investigate the amino acid, free amino acid and fatty acid composition of chicken breast muscle and legs muscle by different raising periods (30, 36 and 42 days). In amino acid composition, the glutamic acids were 3.63% at 30 days, 3.63% at 36 days and 3.54% at 42 days in the breast muscle. The glutamic acid contents in the breast and leg muscle were decreasing tendency as raising periods increased. The total free amino acids were 370.6 mg at 30 days, 235.9 mg at 36 days and 246.3 mg at 42 days in the breast muscle, and those were 470.16 at 30 days, 326.4 mg at 36 days and 321.9 mg at 42 days in the leg muscle. Total contents of free amino acids were higher in chicken legs muscle than in chicken breast muscle. The linoleic acids, the most essential fatty acid, were contained 17.84% at 30 days, 17.84% at 36 days and 20.33% at 42 days in chicken breast muscle. These results indicated that the fatty acid composition increased as raising periods increased. There were 0.69% DHA (Docosahexaenoic acid) in chicken breast muscle at 30 days, 0.96% at 36 days and 1.29% at 42 days. From these results, the DHA contents in chickens were also increased as raising periods increased.

• Korean Journal of Organic Agriculture
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• v.17 no.1
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• pp.111-125
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• 2009

Pitamin is a component of pine bark extract that exhibits antimicrobial activity and a variety of physiological effects. This study was earned out to investigate the effects of dietary pitamin as an organic livestock feed additive in broiler chickens. A 35 day trial was conducted to determine the influence of dietary premix containing 5% pitamin; investigated parameters included blood lipids, growth performance, quality characteristics of carcasses, and changes of caecal microbials in broiler chickens. Chickens were randomly divided into groups that were untreated (control), treated conventionally with antibiotics in the absence of premix, received 0.1 % or 0.2% premix containing 5% pitamin. Plasma lipids were lower in groups fed diets with pitamin premix (p<0.05). The body weight gain from broiler chickens fed with the diet containing 0.1% pitamin premix and antibiotics was similar, and was significantly higher than that of the other groups (p<0.05). The weight of breast muscle and thigh meat of carcasses was similar, and was higher than that of the control group (p<0.05). Abdominal fat and thymus index from chickens receiving either pitamin-supplemented premix was significantly lower and increased, respectively, that of the antibiotic and control groups (both p<0.05). The chickens on the pitamin premix-supplemented diets evidenced significantly higher caecal levels of Bifidobacterium species as compared with the chickens on the control diet (p<0.05). These results suggest that feeding a diet supplemented with a 0.1% premix containing 5.0% pitamin for 35 days maintains the production of broiler chickens at a level comparable to that obtained from the use of antibiotics.