• Economic and Environmental Geology
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• v.49 no.5
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• pp.349-360
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• 2016

This study determined mineralogical characteristics and discussed the meaning of mineralogical changes of the lower Choseon Supergrouop in the Weondong area based on the field geological investigation and the drilling core description using X-ray diffraction (XRD) mineral quantification and Scanning Electron Microscopy (SEM) observation. 100 samples with depth were collected from the core (250 m long) at a site in the study area. Especially, to investigate the changes from the upper Daegi Formation to the lower Hwajeol Formation, the samples were collected closely with the interval of about 0.3 m at this section. All samples were made into power using mortar for XRD. Mineral quantitative analysis was executed using Relative Intensity Ratio (RIR) method with corundum as an internal standard phase. Calcite, $2M_1$ illite and quartz are main constituents in most of samples. Dolomite and siderite are significantly observed in the Sesong Formation. As the results of quantitative analysis for the major minerals, the upper Daegi Formation is dominated by calcite with over 80%. The Sesong Formation includes high percentage of dolomite and siderite with the intercalation of thin layers containing high calcite and $2M_1$ illite contents. Hwajeol Formation is characterized by the alternation between thin layers of $2M_1$ illite and quartz-dominated layer (IQDL) and calcite-dominated layer (CDL). IQDL is more frequent in the lower part, whereas CDL is more common in the upper part. The boundary between Daegi Formation and the Sesong Formation is distinct, whereas the boundary between the Sesong Formation and the Hwajeol Formation tends to be changed gradually in mineralogy. The result of SEM observation shows that quartz and $2M_1$ illite are detrital, and a significant amount of calcite also shows detrital form with some recrystallized one, indicating that the repeated influx of terrestrial materials had changed the mineralogy of the shallow sea depositional environment in the early Paleozoic era.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.297-297
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• 2009

최근 유기농산물에 대한 관심과 요구가 급증하면서 소비자들은 고품질 유기농산물을 선호하고 있어 국내 대부분 유기농가들은 무처리 일반종자를 이용하고 있는 실정이다. 앞으로 국제 기준에 부합하는 채소류 유기재배를 위해서는 유기종자의 이용이 필수적이므로 유기종자 채종체계 확립이 필요한 실정이다. 따라서 본 연구에서는 당근 종자(재래종 heimloom)를 사용하여 유기종자의 채종체계를 확립하고자 하였다. 일반적으로 당근종자 생산은 적어도 2년을 요구한다. Seed to seed 방법과 Root to seed 방법이 이용되고 있는데 본 연구에서는 Root to seed 방법을 사용하였다. Root to seed 방법은 6월에 당근종자를 파종하여 가을에 뿌리를 수확하여 지상부를 5cm 정도 남기고 정지하여 일시 저온저장 하였다가 이듬해 뿌리를 이식하여 새순에서 추대시켜 종자를 수확하는 방법으로 종자 생산성이 높아 종자회사에서 많이 사용하고 있다. 본 연구에서도 Root to seed 방법으로 채종 시험하였다. 2008년도에 파종 및 수확한 뿌리를 저온저장고에 일시 저장 후 1차 이식은 2008년 11월 하순에 노지포장에서 실시하고 이때 월동 중 동해를 막기 위하여 보온덮개로 멀칭 처리하였다. 이듬해 3월 중순에 주간거리 75${\times}$40cm 간격으로 솎음하여 처리당 10주씩 배치하였다. 이식후 뿌리에서 새순 1대를 유도하였고 추대 및 개화 6주후부터 종자가 갈색으로 변하기 시작할 때 채종을 시작하였다. 수확부위는 1차 측지 중 1번째 화지를 대상으로 하였고 화경절단은 화총으로부터 20cm 정도 남겨서 잘랐고 실내에서 1개월 이상 충분히 후숙시킨 후 종자를 정선하여 종자생산성을 조사하였다. 결실율과 발아율 조사는 채종된 종자를 이용하여 종자 충실도와 발아력을 조사하였다. 각 품종별 추대율은 15번 품종과 16번, 24번 품종이 5% 미만으로 매우 부진하였고 그밖에 추대된 묘의 생육 및 발육상은 매우 양호하여 개화에는 커다란 문제가 없었다. 종자 결실율은 23번 품종을 제외한 모든 품종에서 높았고 각 품종별 화총구조를 고려해 볼 때 주간 화총, 1차측지, 2차측지 순으로 결실율이 떨어졌다. 각 품종의 천립중은 1, 11, 12, 14, 20번 품종이 2.02g 이상으로 대립종으로 판단되며 각 품종별 화총의 크기는 비슷하여 대립종은 각 화총당 종자수가 적은 것으로 나타났다. 대분분의 대립종은 만생종으로 생육기간이 소립종 보다 10-20일상 길며 종자 성숙기간도 장기간 소요되며 특히 장마기간을 넘겨야 할 경우에는 비가림 시설 채종재배가 필수적인 것으로 나타났다. 발아율은 10, 11, 14, 18, 19, 26번 품종이 80% 이상으로 가장 높았고 다른 품종에서는 다소 떨어져 품종별 차이가 많았다. 종자 생산성은 장근종과 단근종간에 약간의 차이가 있지만 주간 화총을 포함하여 1차 측지 4-5개에서 채종하는 것이 가장 효율적인 것으로 사료된다. 또한 당근의 개화 기간을 보면 1화륜은 8~10일, 1개체는 40~50일, 채종포장에서는 1화륜에서 측지 6개구까지 채종은 60~70일 소요되어 미숙종자와 과숙종자가 혼재되어 적정 수확시기를 결정하기가 매우 어려운 점이 발생하였다. 본 연구 결과에서 생육특성, 수량성, 품질특성, 종자 생산성, 발아율을 고려해 볼 때 1, 7, 8, 9, 10, 14, 19, 26번 품종이 유기농 재배 및 유기채종에 적합한 것으로 사료되었다.

• Korean Journal of Poultry Science
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• v.30 no.4
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• pp.289-299
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• 2003

Effects of various combinations of corn oil (CO) and perilla oil (PO) as respective dietary sources of ${\omega}$-6 and ${\omega}$-3 polyunsaturated fatty acids on fatty acid profiles of immune organs were studied in young chicks. Seventy-five 1-day-old male (ISA Brown) chicks were assigned to five treatments with three replications. Semi-purified-type diets containing glucose and soybean meal as major ingredients were added with 8% CO, 6% CO+2% PO, 4% CO+4% PO, 2% CO+6% PO and 8% PO and fed for 7 weeks. There were no significant differences in body weight gain, feed intake and relative weights of liver and immune organs (g/100g weight) among dietary groups. Dietary fatty acid patterns were generally reflected in the fatty acid compositions of all immune organs such as spleen, thymus and bursa of Fabricius. The levels of a-linolenic acid(LNA), eicosapentaenoic acid (EPA) and docosahexaenoic acid in various immune organs increased with increasing levels of perilla oil in the diets, whilet the levels of linoleic acid (LA) and arachidonic acid (AA) decreased. Thymus appeared to have capacity to retain remarkably higher (P<0.05) levels of LA and LNA up to 37 and 22%, respectively, compared to the other organs. Thymic tissue contained ${\omega}$-3 fatty acid and ${\omega}$-6 fatty acid 10~36 times and 3~5 times higher than the other organs, respectively. Spleen tissue was specifically higher (P<0.05) in the levels of AA and EPA and the ratios of AA/LA and EPA/LNA, compared to the other organs, suggesting that the tissue might have high desaturase activity to convert LA or LNA to AA or EPA, respectively. BSA antibody production tended to increase by 18 ~ 32% with higher levels of perilla oil in diet, although the increase was not statistically significant. In conclusion, fatty acid compositions of immune organs very depending on the lipid composition of the diets and each organ appears to respond differently for its fatty acid profile to dietary lipids. Considering AA and EPA are precursors of many important eicosanoids, further studies are required to clarify the responses of the immune organs to the dietary fatty acids.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.179-185
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• 1998

This study was conducted to investigate changes in weed occurrence and dominance as affected by seeding dates in water seeded rice paddy under field following two years of no-tillage condition. The pre-emergence weeds in no-tillage paddy were controlled by glyphosate application at 7 days before seeding. The rice seeds were seeded on April 20, May 10 and May 30, respectively with 40kg/ha of seeding rate. The weed species in the paddy occurred included three species (Echinochloa cursgalli, Aneilma keisak, Ottelia alismoides) of annual weed, one species (Alopecurus aequalis) of biennial weed and five species (Eleocharis kuroguwai, Leersia japonica, Sagittaria pygmaea, Sagittaria trifolia, Potamogeton distinctus) of perennial weed respectively. Aneilma keisak was found to be dorminant on April 20 and May 10 but Eleocharis kuroguwai on May 30 based on number of weeds. The number and dry weight of weeds occurred were higher on May 10 as compared to in other seeding dates, while proportion of perennial weeds increased as the seeding date was delayed. In particular, weed dorminance varied marketly with seeding date. The Simpson's indices were 0.736 on April 20, 0.261 on May 10 and 0.281 on May 30, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.1
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• pp.23-28
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• 2011

Resveratrol has been associated with reduced cardiovascular disease and reduced cancer risk. This phytochemical has been reported in a number of plant species including grapes, peanuts and pine trees in response to stress such as fungal infection, heavy metal ions or UV irradiation. The objective of this study was to determine the resveratrol contents in leaves of mulberry varieties at different collecting times. Quantitative analysis of 16 cultivars showed a range of $102{\sim}466{\mu}g/100g$ on dry weight basis (which is equivalent to $25{\sim}116.5{\mu}g/100g$ on fresh weight basis). Resveratrol contents in mulberry leaves was higher in autumn than spring, and higher in fully matured leaves than in juvenile leaves. Among the tested samples, 'Kaeryangppong', 'Sugeppong' and 'Cheongilppong' collected in the middle of October showed high resveratrol contents of $838{\mu}g/100g$, $803{\mu}g/100g$, $800{\mu}g/100g$ on dry weight basis, respectively. Especially mulberry leaves dried in the shade showed of $1,030{\mu}g/100g$ on dry weight basis in resveratrol content, this result may contribute to utilization of mulberry leaves.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.1
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• pp.50-56
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• 2011

This study was designed to investigate variation of pinitol content in different parts of seventeen legume species including silk tree (Albizia julibrissin). D-pinitol has been demonstrated to exert insulin-like and anti-inflammatory effects. These legumes were collected from Gyeongsangbuk-Do in Korea. Significant difference in pinitol content was observed among 17 different legume species. However, it was the highest in sericea lespedeza (Lespedeza cuneata). The highest pinitol content was observed in leaf followed by stem, pod shell, seed and root among plant parts. Legume plants which had higher pinitol content in leaves were chinese pea shrub, bastard indigo, wild cowpea and sericea lespedeza, having 59.9 mg/g, 62.2 mg/g, 69.6 mg/g and 65.4 mg/g, respectively. Stem of astragali radix showed the highest pinitol content among all leagumes, which was 34.0 mg/g. In case of root, kudzuvine showed the highest pinitol content followed by licorice and chinese pea shrub, which were 24.6 mg/g, 16.9 mg/g, and 16.5 mg/g, respectively. However, in the case of pod shell and seed, only lablab purpureus and sericea lespedeza showed the highest pinitol content 52.5 mg/g (for pod shell) and 24.9 mg/g (for seed), respectively. Concluding, the sericea lespedeza showed the highest total pinitol content of whole plant followed by chinese redbud, chinese pea shrub, bastard indigo and silk tree. Considering the pinitol content and harvesting yield, sericea lespedeza can be used as a practical medicinal herb.

• Economic and Environmental Geology
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• v.42 no.4
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• pp.315-333
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• 2009

In this study, the hydrochemical and the isotopic characteristics of major streams in the Daejeon area were investigated during rainy and dry seasons. The stream water shows the electrical conductivity of the range of $37{\sim}527{\mu}s$/cm, and pH $6.21{\sim}9.83$. The chemical composition of stream waters can be grouped as three types: the upper streams of Ca(Mg)-$HCO_3$ type, Ca(Mg)-$SO_4(Cl)$ type of middle streams flowing through urban area, and Na(Ca)-$HCO_3$(Cl, $SO_4$) type of the down streams. Based on in-situ investigation, the high pH of stream waters flowing through urban area is likely to be caused by the inflow of a synthetic detergent discharging from the apartment complex. The electrical conductivity of stream waters at a dry season is higher than those of at a rainy season. We suggest that the hydro-chemical composition of stream waters in the Daejeon area was affected by the discharging water from the sewage treatment facilities and anthropogenic contaminants as well as the interaction with soil and rocks. ${\delta}D$ and ${\delta}^{18}O$ values of the stream waters show the relationship of ${\delta}D=6.45{\delta}^{18}O-7.4$, which is plotted at a lower area than global meteoric water line(GMWL) of Craig(1961). It is likely that this isotopic range results from the evaporation effect of stram waters and the change of an air mass. The isotope value shows an increasing trend from upper stream to lower stream, that reflects the isotopic altitude effect. The relationship between ${\delta}^{13}C$ and $EpCO_2$ indicates that the carbon as bicarbonate in stream water is mainly originated from $CO_2$ in the air and organic materials. The increasing trend of ${\delta}^{13}C$ value from upper stream waters to lower stream waters can be attributed to the following reasons: (1) an increasing dissolution of $CO_2$ gas from a contaminated air in downtown area of the Daejeon, and (2) the increment of an inorganic carbon of groundwater inflowed into stream by base flow. Based on the relationship between ${\delta}^{34}S$ and $SO_4$ of stream waters, the stream waters can be divided into four groups. $SO_4$ content increases as a following order: upper and middle Gab stream${\delta}^{34}S$ value decreases as above order. ${\delta}^{34}S$ value indicates that sulfur of stream waters is mainly originated from atmosphere, and is additionally supplied by pyrite source according to the increase of sulfate content. The sulfur isotope analysis of a synthetic detergent and sewage water as a potential source of the sulfur in stream waters is furtherly needed.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.188-197
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• 2008

This research was a preliminary case study to determine the levels of total mercury in the tissues of sentinel species (Zacco platypus) and ecological health in relation to habitat characteristics and chemical conditions. We collected fishes in Gap Stream during June$\sim$October 2007 and analyzed the total mercury from five types of tissues such as liver, kidney, gill, vertebrae and muscle of Zaceo platypus using Direct Mercury Analyzer (DMA-80, US EPA Method 7473). Mean concentrations of total [Hg], based on all tissues, was 67.2 and $20.7\;{\mu}g\;kg^{-1}$, in the upstream and downstream site, respectively, indicating 3 times greater level in the upstream. In other words, the levels were higher in the pristine upstream than the downstream influenced by the wastewater disposal plant. Chemical water quality, based on BOD, COD and nutrients (TN, TP) showed that severe degradation occurred in the downstreams than the upstreams. Index of Biological Integrity (IBI) using fish multi-metric model averaged 32, indicating a "good$\sim$fair" condition and varied from 42 (excellent$\sim$good) at S2 to 22 (fair$\sim$poor) at S5 depending on the sites sampled. Qualitative Habitat Evaluation Index (QHEI) in the all sites averaged 142, which was judged as "good" habitat health, but showed a high variation (181 in Site 2 vs. 67 in Site 5). Overall data suggest that health conditions, based on IBI and QHEI, was better in the upstream sites but the mercury bioaccumulation levels in the fish tissues were opposite. We believe that measurements of various parameters are required for a diagnosis of integrative ecosystem health.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.29-45
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• 2017

This study explored spatiotemporal variability of water quality in correspondence with hydro-meteorological factors in the four stations of Euiam Reservoir located in the upstream region of the North-Han River from May 2012 to December 2015. Seasonal effect was apparent in the variation of water temperature, DO, electric conductivity and TSS during the study period. Stratification in the water column was observed in the near dam site every year and vanished between August and October. Increase of nitrogen nutrients was observed when inflowing discharge was low, while phosphorus increase was distinct both during the early season with increase of inflowing discharge and the period of severe draught persistent. Duration persisting high concentration of Chl-a (>$25mg\;m^{-3}$: the eutrophic status criterion, OECD, 1982) was 1~2 months of the whole year in 2014~2015, while it was almost 4 months in 2013. Water quality of Euiam Reservoir appeared to be affected basically by geomorphology and source of pollutants, such as longitudinally linked instream islands and Aggregate Island, inflowing urban stream, and wastewater treatment plant discharge. While inflowing discharge from the dams upstream and outflow pattern causing water level change seem to largely govern the variability of water quality in this particular system. In the process of spatiotemporal water quality change, factors related to climate (e.g. flood, typhoon, abruptly high rainfall, scorching heat of summer), hydrology (amount of flow and water level) might be attributed to water pulse, dilution, backflow, uptake, and sedimentation. This study showed that change of water quality in Euiam Reservoir was very dynamic and suggested that its effect could be delivered to downstream (Cheongpyeong and Paldang Reservoirs) through year-round discharge for hydropower generation.

• Restorative Dentistry and Endodontics
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• v.32 no.2
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• pp.111-120
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• 2007

The purpose of this study is to evaluate the effects of surface treatment and composition of reinforcement material on fracture strength of fiber reinforced composite inlay bridges. The materials used for this study were I-beam, U-beam TESCERA ATL system and ONE STEP(Bisco, IL, USA). Two kinds of surface treatments were used; the silane and the sandblast. The specimens were divided into 11 groups through the composition of reinforcing materials and the surface treatments. On the dentiform, supposing the missing of Maxillary second pre-molar and indirect composite inlay bridge cavities on adjacent first pre-molar disto-occlusal cavity, first molar mesio-occlusal cavity was prepared with conventional high-speed inlay bur. The reinforcing materials were placed on the proximal box space and build up the composite inlay bridge consequently. After the curing, specimen was set on the testing die with ZPC. Flexural force was applied with universal testing machine (EZ-tester; Shimadzu, Japan). at a cross-head speed of 1 mm/min until initial crack occurred. The data was analyzed using one-way ANOVA/Scheffes post-hoc test at 95% significance level. Groups using I-beam showed the highest fracture strengths (p<0.05) and there were no significant differences between each surface treatment (p>0.05) Most of the specimens in groups that used reinforcing material showed delamination. 1. The use of I-beam represented highest fracture strengths (p<0.05) 2. In groups only using silane as a surface treatment showed highest fracture strength, but there were no significant differences between other surface treatments (p>0.05). 3. The reinforcing materials affect the fracture strength and pattern of composites inlay bridge. 4 The holes at the U-beam did not increase the fracture strength of composites inlay bridge.