• Title/Summary/Keyword: density index

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Correlation of the Consolidation Characteristics of Inland and Harbour District Soil (육상 및 항만지역상의 압밀특성치의 상관성)

  • 도덕현;이성태;강우묵
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.25 no.4
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    • pp.50-60
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    • 1983
  • 305 samples of alluvial deposit in inland and harbour districts were selected and consolidation charateristics of the alluvium were put in order statiscally. The correlations between them were as follows. 1. The relationships between LL(liguid limit) and Cc (compression index) were explained as Cc=0. 03(LL-21. 7) in case of inland district soil and as Cc=0. 019(LL-19) in case of harbour district soil. As compared with formular proposed by Skernpton, the gradient of this linear line was slight steep. 2. The relationships between PI(plastic index) and Cc were explained as Cc=0. 063 PI-0. 52 in case of inland district soil and Cc=0. 043 PI-0. 31 in case of harbour district soil. 3. As void ratio and natural moisture content were increased, Cc was increased, and as wet density was increased, Cc was decreased with a gentle curve. 4. As LL and P1 increased, mv(coefficient of volume compressibility) was increased but if LL and P1 was increased beyond a certain extend, mv has a tendency of constant value, that is, mv show a tendency to take constant value in the very soft clay. and mv in P=2. 5kg/cm$^2$ was about l${\times}$ l0-$^1$cm$^2$/kg in case of land district soil and 6x 10-$^1$crn$^2$/kg in case of harbour district soil lower than that in P=0. 25kg/crn2. 5. Cv(coefficient of consolidation) was a tendency to decrease with a gentle curve as LL was increased, and Cv in P=0. 25kg/crn2 was about 3x l0-$^1$crn$^2$/min larger than that in P=2. 5kg/crn$^2$. 6. Relationships between Py(pre-consolidation pressure) which is included over consolidation soil and ∑r1h(effective over-burden pressure) were explained as Py=l. 12 ∑r'h in case of land district soil and as Py=l. l5∑r'h in case of harbour district soil. 7. Some of the properties show good correlations between them, practical and effective applications of these correlations are expected in the planning and excution of soil investigation and also in the evaluation of the results.

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An Evaluation Method for Sesame (Sesamum indicum L.) Resistance to Phytophthora nicotianae var. parasitica (참깨발병 품종저항성 검정방법 연구)

  • Seong Ho, Choi;Eui Kyoo, Cho;Young Am, Chae
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.32 no.2
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    • pp.173-180
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    • 1987
  • Symptom development and disease severity of Phytophthora blight in the sesame plants varied depending upon age of the plants tested, inoculation method, watering method, and inoculum density in both susceptible Suweon 9 and Suweon 26 and moderately resistant B-67 and IS 103 sesame lines to Phytophthora nicotianae var. parasitica when inoculated. However, successful differentiation of the sesame lines for varietal resistance was possible using 20-day old seedling, inoculation by soil infestation, saturated soil water condition by half immersion of pots in water tank, and 200 sporangia per one ml of inoculum. Spraying or soil inoculation to 70-day old plants also was effective in differentiating the varietal resistance. By the screening method Suwon 26 showed 100% diseased plants and symptom severity index 9.0, while B-67 showed 20% diseased plants and symptom severity index 1.7. The rating scale given was from 0 through 9. For example, the scale 0 signified no symptom development, 5 signified discoloration of basal part of stem, and 9 signified discoloration of stem more than 10 cm high above the soil surface with blighted leaves. Differentiation in symptom severity also was made by percentage of the lesion area. Results evaluated using both parameters were well corresponded in varietal reaction of sesame to Phytophthora blight.

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Landslide Susceptibility Mapping and Verification Using the GIS and Bayesian Probability Model in Boun (지리정보시스템(GIS) 및 베이지안 확률 기법을 이용한 보은지역의 산사태 취약성도 작성 및 검증)

  • Choi, Jae-Won;Lee, Sa-Ro;Min, Kyung-Duk;Woo, Ik
    • Economic and Environmental Geology
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    • v.37 no.2
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    • pp.207-223
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    • 2004
  • The purpose of this study is to reveal spatial relationships between landslide and geospatial data set, to map the landslide susceptibility using the relationship and to verify the landslide susceptibility using the landslide occurrence data in Boun area in 1998. Landslide locations were detected from aerial photography and field survey, and then topography, soil, forest, and land cover data set were constructed as a spatial database using GIS. Various spatial parameters were used as the landslide occurrence factors. They are slope, aspect, curvature and type of topography, texture, material, drainage and effective thickness of soil. type, age, diameter and density of wood, lithology, distance from lineament and land cover. To calculate the relationship between landslides and geospatial database, Bayesian probability methods, weight of evidence. were applied and the contrast value that is >$W^{+}$->$W^{-}$ were calculated. The landslide susceptibility index was calculated by summation of the contrast value and the landslide susceptibility maps were generated using the index. The landslide susceptibility map can be used to reduce associated hazards, and to plan land cover and construction.

Distribution of Sedimentation Environments and Benthic Macro-fauna Communities in Habitats and Non-habitats of Zostera marina on the Yeongheung-do Tidal Flats, West Coast of Korea (한국의 서해안 영흥도 조간대의 거머리말(Zostera marina) 서식지와 비서식지에서 퇴적환경과 대형저서동물군집의 분포)

  • Bae, Jong Il;Shin, Hyen Chul;Hwang, Sung Il;Lee, Jeng Ho
    • Korean Journal of Environmental Biology
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    • v.36 no.2
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    • pp.107-116
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    • 2018
  • In this study, the distribution of sedimentary environment and benthic macro-fauna in habitats and non-habitats of Zostera marina were investigated. The purpose of this study was to obtain basic data about the sedimentary environment and benthic macro-fauna in the habitats and non-habitats of Z. marina. Sand was dominant within habitat environments, whereas the non-habitats were predominantly composed of silt. As a result, the habitats of Z. marina have a different grain size and organic matter content compared to the non-habitats. These differences in the sedimentary environment were expected to influence the species composition of benthic animals. Benthic communities in the habitats of Z. marina showed a higher density and a greater number of species than in the non-habitats. As a result of an ecological index evaluation, the species diversity index (H') was $3.44{\pm}0.10$ for the habitat; the non-habitat was analyzed as $2.34{\pm}0.35$. It was also found that the stability of community in the habitats was higher than that in the non-habitats. The cluster analysis also clearly showed that habitats and non-habitats of Z. marina have distinct characteristics.

Effects of Paprika (Capsicum annuum L.) on Serum Lipid Profile and $\alpha$-Tocopherol Concentration in Rats Fed a High-Cholesterol Diet (파프리카 급여가 고콜레스테롤 식이 흰쥐의 혈청 지질과 $\alpha$-Tocopherol 농도 변화에 미치는 영향)

  • Park, Jae-Hee;Noh, Sang-K.;Kim, Chang-Soon
    • The Korean Journal of Food And Nutrition
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    • v.23 no.3
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    • pp.311-317
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    • 2010
  • In conclusion, rats were fed diets containing either NC, HC, HC-FDP, HC-WEP, or HC-EEP for 6 weeks. At the 6th week, increases in body weight and visceral fat were lower in the paprika fed groups as compared to the HC group. Serum levels of triglycerides, total cholesterol, low density lipoprotein cholesterol, and atherogenic index values were significantly lower in the paprika diet fed groups than the HC group (p<0.05). In particular, the lipid lowering effects in the HC-EEP group were superior among the paprika fed groups. Also, serum $\alpha$-tocopherol levels were lower in the control group compared to the paprika fed groups. The supplementation of paprika may exert lipid lowering effects and saving effect of $\alpha$-tocopherol in the serum of high-cholesterol diet fed rats. However, it should be noted that the results are based on very small sample numbers and a short experimental period.

Habitat Environment and Vegetation Structure of Forest Communities Growing Schisandra nigra Maxim. in Cheju Island of Korea (흑오미자 자생 임분의 입지환경과 식생구조)

  • Lee Kab-Yeon;Kim Sea-Hyun;Kim Pan-Gi;Shin Chang-Ho;Han Sang-Sup
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.1 no.2
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    • pp.81-89
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    • 1999
  • To propose basic information for natural resource management and conservation strategy of Schisan-dra nigra Maxim., its habitat environment and vegetation structure of forest communities growing the species was investigated. Fourteen plots (each plot size 400 $m^2$) were set up at the distributed area of Cheju island, southern part of Korea. S. nigra is the economic useful species that scatteringly grows at 850~920 m in the western part, at 660~710 m in the northern part and at 750~1,250 m in the southern part of Mt. Halla. The community of S. nigra in Mt. Halla is the mixed secondary forest of pine and broad leaved trees that are mainly composed of Pinus densif1ora, Quercus serrata, Styrax japonica, Lin-dera erythrocarpa and Carpinus laxiflora. The density in a main distribution sector of S. nigra appears in the range of 3~39 individuals per each 20$\times$20 m plot. The distribution patterns by Morisita's Index showed that S. nigra was distributed randomly in all of the stands. The association analysis showed that the following tree species were positively associated with S. nigra. In other words, the following trees were appeared to require the same ecological niche together with S. nigra: Lindera erythrocarpa, Cornus waltri, Acer mono, and Styrax japonica.

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Ecological variations of macrobenthos in subtidal at Chonsu bay in Chungcheongnam-do, Korea (천수만 조하대에 서식하는 대형저서동물의 생태학적 변화 연구)

  • Han, Hyoung-Sum;Ma, Chae-Woo;Choi, Man-Sik
    • Korean Journal of Environment and Ecology
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    • v.29 no.3
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    • pp.421-430
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    • 2015
  • This study was carried out to understand the ecological variations of macrobenthos communities by construction dikes in the subtidal zone of Chonsu Bay. This study analyzed the distribution of benthos, the dominant species, spatial and temporal changes of benthos communities and benthic pollutions in the subtidal zone of Chonsu Bay. A total of 252 species of subtidal macrobenthos with a density of $681ind./m^2$ were studied. In all the seasons, the species diversity was found to be higher near the mouth of the bay. For all the seasons of the year, Lumbrineris japonica was found to be the most dominant species. These dominant species were found to have positive correlations with species diversity and sedimentary parameters such as organic content in sediments. Dominant species of benthos as well as species composition and diversity showed spatial and temporal distribution patterns.Benthic Pollution Index (BPI) values estimated for the stations near the embankment were in the 4~5 levels, which indicates that the organic matter has been polluted. And as for the stations near the mouth of the bay, the BPI values were in the 1~3 levels, which indicates that the organic matter has been relatively less polluted. According to the SAB-curve analysis, the number of transitional point stations became less in the mouth of the bay.

The Spectral Characteristics of Climatological Variables over the Asian Dust Source Regions and its Association with Particle Concentrations in Busan (황사 발원지 기후자료의 시계열 특성과 부산지역 먼지 농도의 연관성 분석)

  • Son, Hye-Young;Kim, Cheol-Hee
    • Journal of the Korean earth science society
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    • v.30 no.6
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    • pp.734-743
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    • 2009
  • In order to examine how climatological condition can influence on urban scale particulate air pollutants, single and cross spectrum analysis have been performed to daily mean concentrations of particulate matters ($PM_{10}$) in Busan together with the climatological variables over the Asian dust source regions. Single power spectrum analysis of $PM_{10}$ concentrations in Busan shows that, aside from the typical and well-known periodicities, 3-4 year of peak periodicity of power spectrum density was identified. In cross spectrum analysis, this 3-4 year periodicity is found to have a strong positive correlation with the wind speed and pressure, and negative with the temperature and relative humidity, which is rather consistent with both characteristics of air mass during the Asian dust event whose periodicities have been recorded inter-annually over the Korean urban cities. Over the Asian dust source regions, $PM_{10}$ vs. precipitation shows no significant periodicity from the time series of precipitation data, but the periodicity of EDI (Effective Drought Index) shows some interannual variabilities ranging from 2 to 4 years over the various source regions, suggesting that, rather than precipitation itself, the EDI could be more closely associated with the occurrence frequency of Asian dust and interannual variability of urban particle concentrations in Korean cities.

Short-term changes of community structure of microbenthic invertebrates in the coastal waters Jeju Island, Korea from 2013 to 2015 (제주연안 저서무척추동물 군집구조의 단기변화 (2013-2015))

  • Ko, Jun-Cheol;Kim, Bo-Yeon;Sonh, Myoung-Ho;Jo, Woon-Chan;Lee, Kwan-Cheol
    • The Korean Journal of Malacology
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    • v.32 no.4
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    • pp.297-328
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    • 2016
  • This study was performed to know and compare the community structures of macrobenthic invertebrates of five fishing grounds in the coastal waters of Jeju Island from 2013 to 2015. A total of 629 species was identified. Molluscans comprised 282 species (44.8%), Arthropods 88 (14.0%), Poriferans 61 (9.7%), Bryozoans 52 (8.3%) and the others including Cnidarians 51 (8.1%). Density and biomass were estimated to be $71,007ind./m^2$ and $599,208.0gwwt/m^2$, respectively. Gastropods was the most dominant taxon in terms of abundance ($24,625ind./m^2$ ) and number of species as well, and Gastropods was predominant in biomass ($190,789.0gwwt/m^2$). The dominant species were Omphalius pfeifferi, Astralium haematragum, Musculus viridulus, Halosydna brevisetosa, Phascolosoma scolops, Herdmania monus in 5-20 m. Based on the cluster analysis, the study area could be divided into five station groups. The biodiversity, evenness and richness index appeared as follows: H' = 4.28-4.64, E' = 0.74-0.79, R = 33.17-35.45. The dominance index were highest in Sagye and lowest in Sinhung.

UVB-INDUCED CHANGES OF BARRIERFUNCTION AND MORPHOLOGY OF THE HAIRLESS MOUSE SKIN (자외선-B에의한 Hairless mouse의 보호기능과 표면구조의 변화 영향)

  • Kim, Jin-Jun;Park, Mun-Eok;Gang, Se-Hun
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.18 no.1
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    • pp.81-98
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    • 1992
  • Hairless mice (Skh:HR-1) exposed to single doses (0.5, 1.0 and 3. OMED) of UV-B radiation were displayed remarkable changes of barrier function and surface morphology. Trans- epidermal water loss (TEWL) as an index of barrier function was measured by evaporimeter, and wrinkle density (WD) as an index of morphological alteration was measured by image analyzer. Significant changes of TEWL were not observed in the control and 0. SMED group, but 1.OMED and 3. OMED groups noted significant difference. TEWL of 3. OMED group was rapidly increased to the 3rd day and decreased until the 14th day when it reached nearly to normal level, Time-courses of TBWL for 1. OMEB and 3. OMED groups displayed similar pattern, but different only in the magnitude. WD were significantly decreased during the 3rd-5th day in all of the irradiated groups and then increased during the last period to the 14th day, but did not recover the normal level at the 14th day. Time-courses of WD for all groups exhibited similarity, and were entirely dependent on the exposed doses. We also observed histological changes which included hyperplasia, sunburn cell (SBC) formation, accumulation of polymorphonuclear leukocyte (PMNs), and loss of collagen of UVB- exposed hairless mouse skin. Changes of TEWL and WD are helpful in understanding of epidermal and dermal damages by single exposure of UVB.

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