• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.279-284
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• 1999

Fly ash is the fine ash particles that are flying out of chimney of the thermoelectric power plant where coals are used as fuel. There are two kinds of fly ashes from anthracite and bituminous coal. By scanning electron microscope(SEM) morphological feature of fly ash was confirmed to the exact spherical particles with the diameter variation from the fine to the largest about $50{\mu}m$(mainly silty particle). Surface of anthracite ash particle was very smooth but that of bituminous was somewhat coarse. To find the utilization of fly ash for improving soil permeability, soils of 4 kinds of different texture, clay, clay loam, sandy clay loam and sand mere applied with 7 levels of fly ash: 0, 10, 20, 40, 60, 80, 100%(w/w) and their saturated hydraulic conductivity(Ks) were determined at each application by constant head method. In clay soil with low water permeability, Ks value was increased about 10 times from $10^{-8}$ to $10^{-7}m\;s^{-1}$ level with application of 10% fly ash and it was slightly increased with increasing fly ash application from 40 to 80%. In clay loam Ks value was about $10^{-7}m\;s^{-1}$ level and its value was not influenced by the fly ash application. In sandy clay loam with relatively high permeability, Ks value was decreased about 10 times from $10^{-5}$ to $10^{-6}m\;s^{-1}$ level with application of 10% fly ash and also decreased about 50 times from $10^{-5}$ to $5.0{\times}10^{-7}m\;s^{-1}$ with application of more than 20% fly ash. In sand with very high permeability, Ks value was decreased about 10 times from $10^{-4}$ to $10^{-5}m\;s^{-1}$ level with application of 10% fly ash and also decreased about 100 times from $10^{-4}$ to $10^{-6}m\;s^{-1}$ level with application of 20% fly ash and continuously decreased about 500 times from $10^{-4}$ to $5.0{\times}10^{-7}m\;s^{-1}$ level with application of more than 40% fly ash. In conclusion by fly ash application saturated hydraulic conductivity was increased in clay soil, on the contrary it was decreased in sandy soils. Fly ash may be used as a material for amelioration of soil permeability.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.3
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• pp.141-152
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• 1973

The mineralogical studies of the eleven sub-soil samples derived from granite, granodiorite, diorite and arkose sandstone, taken from apple orchards in the province of Kyungsangbukdo, Korea are made to investigate the relationships between the mineral weathering, soil forming processes and mineralogical composition. The fine sand fraction (less than 0.2mm) and the clay fraction (less than 2 micron) are dispersed with the shaker after hydrogen peroxide treatment for the removal of organic matter, and separated from each suspension by gravity sedimentation. The fine sand are observed by mineral microscope and the clay are observed by X-ray diffraction patterns, differential thermal analysis curves and infrared spectrum. The outline of the results are as follows. 1. The primary minerals ; Quartz, changed-feldspar, plagioclase, alkali-feldspar are dominant in almost all samples, and some samples contain an appreciable amount of hornblende, biotite, muscovite and plant opal. There are also those samples which contain very small quantity of pyroxene group, tourmaline, epidote, cyanite, magnetite, volcanic glass and zircon. They are mainly derived from weathering products of granite, granodiorite, diorite, arkose or its mixtures. 2. All samples contain expanding or nonexpanding $14{\AA}$ minerals, illite and kaolin minerals, and some samples contain chlorite, cristobalite, gibbsite, and those primary minerals as quartz and feldspar, but the quantities vary according to the parent matrials. 3. Non-expanding $14{\AA}$ minerals may be dioctahadral vermiculite which sandwiches gibbsite layer or chlorite in between layer lattices. 4. As for clay minerals, montmorillonite was principal component in the samples derived from weathering products of arkose sandstone and tertiary. Minerals which are derived from weathering products of arkose have kaolin minerals and vermiculite as their principal component, and minerals derived from weathering products of acidic rock group are generally classified into two groups, the kaolin mineral group, and the kaolin minerals and vermiculite group.

• Journal of the Geological Society of Korea
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• v.54 no.5
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• pp.477-488
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• 2018

Fluid muds commonly occur in estuarine environments, but their ancient examples have rarely been studied in terms of depositional characteristics and processes. Cores of estuarine channel deposits of the Early Cretaceous McMurray Formation, Alberta, Canada show various mudstone layers that possess depositional characteristics of high clay-concentration flows. These mudstone layers are examined in detail through microscopic observation of thin sections and classified into three microfacies (<1 to 25 mm thick) on the basis of sedimentary texture and structures. Structureless mudstone (Microfacies 1) consists mainly of clay particles and contains randomly dispersed coarser grains (coarse silt to fine sand). This microfacies is interpreted as being deposited by cohesive mud flows, i.e., fluid muds, which possessed sufficient strength to support suspended coarser grains (quasi-laminar plug flow). Silt-streaked mudstone (Microfacies 2) mainly comprises mudstone with dispersed coarse grains and includes very thin, discontinuous silt streaks of coarse-silt to very-fine-sand grains. The texture similar to Microfacies 1 indicates that Microfacies 2 was also deposited by cohesive fluid muds. The silt streaks are, however, suggestive of the presence of intermittent weak turbulence under the plug (upper transitional plug flow). Heterolithic laminated mudstone (Microfacies 3) is characterized by alternation of relatively thick silt laminae and much thinner clay laminae. It is either parallel-laminated or low-angle cross-laminated, occasionally showing low-amplitude ripple forms. The heterolithic laminae are interpreted as the results of shear sorting in the basal turbulent zone under a cohesive plug. They may represent low-amplitude bed-waves formed under lower transitional plug flows. These three microfacies reflect a range of flow phases of fluid muds, which change with flow velocities and suspended mud concentrations. The results of this study provide important knowledge to recognize fluid-mud deposits in ancient sequences and to better understand depositional processes of mudstones.

• Asian Journal of Turfgrass Science
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• v.17 no.4
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• pp.155-163
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• 2003

This study was conducted to find out suitable rootzone profile, irrigation system, and turfgrass species for roof turf garden. Treatments of profile with soil amendment were Mixture I: Perlite(PL)60％＋Vermiculite(VC)20％＋Peatmoss(PM)20％, Mixture II: PL60％＋VC 10％＋PM20％＋Sand(SD)10％, Mixture III: PL60％＋VC20％＋PM20％ and Mixture IV: PL60％＋VC10％＋PM20％＋SD10％＋Styrofoam 5cm as a drain layer. To test trickle irrigation for roof garden, intervals of main pipe spacing(50cm, 100cm) and drop hole distance(15, 20, 30, 50 and 100cm)were treated, To select most suitable turfgrass species or mixture, Bermudagrass 'Konwoo', Zoysiagrass 'Konhee' and cool-season grass(Kentucky Bluegrass 80％ ＋ Perennial Ryegrass 20％, Tall Fescue 30％ ＋ KB50％ ＋ PR 20％)were tested. In particle size analysis, the soil amendments Perlite and vermiculite showed very even distribution, however, peatmoss contained mostly coarse particles with fiber over $\Phi$ 4.75mm. Under field moisture condition, vermiculite and peatmoss showed 350％ water holding capacity, on the other hand, sand or Perlite showed 115％ and 166％, respectively. Total weight of soil profile was 139.2kg/$m^2$ with Styrofoam drain layer without sand, which showed most lightest among treatments. Turf quality also resulted positve with Styrofoam drain layer installation. On trickle irrigation system, the proper interval of main drain pipe spacing and drop hole distance were 50cm and 50cm, respectively, In irrigation frequency, once per a day for 15 minute irrigation with 2 1/hr showed the best results on turf quality. Among turfgrass species or cool season grass mixture, warm season turfgrass fine leaf type zoysiagrass 'Konhee' and Bermudagrass 'Konwoo' showed very acceptable result on all over the treatments of rootzone and irrigation system. To apply cool season grasses for the roof garden, advanced researches may be needed to establish the proper soil amendment, rootzone profile, and irrigation system, Application of Bermudagrass 'Konwoo' for roof turf garden also needs successive tests to overcome winter injuries.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.4
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• pp.358-371
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• 2014

For the systematic scientific management in Cheonsu Bay of Korea, this study was conducedt to survey the particle composition, organic matter(I.L.) and heavy metals in farming and non-farming areas. The sediment of study area showed feature mixed property by sand, silt and clay. The farming area showed superior by fine-grained sediment, non-farming area showed superior by coarse-grained sediment. The organic pollution of farming area were appeared to be heavily polluted more than non-farming area. The concentration of total nitorgen in sediment was higher farming area than non-farming area. Also, in the case of heavy metals pollution in sediments, farming area was higher than non-farming area. The correlation analysis among to heavy metals, organic matter and particle size was found to have a good interrelationship. For evaluation of heavy metals pollution of sediments, three criteria are applied, Enrichment Factor(EF), Geoaccumulation index(Igeo) and NOAA criteria for sediment. In the case of EF, Heavy metals pollution was appeared to artificial effect all heavy metals if except Cu. In the case of Geoaccumulation index, Cu, Al, Pb was shown zero grade, that is non polluted group, and Cd, Hg, Cr was shown to 0~1 grade, that is mid polluted group, As was shown to 2 grade, that is moderately polluted group. In the case of NOAA, pollution levels of heavy metals except Cd belonged to a group of ERL(Effect range low)~ERM(Effect range median).

• Journal of the Korean earth science society
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• v.45 no.3
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• pp.203-213
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• 2024

This study aimed to investigate the seasonal patterns of multiple bar formation in summer and flattening in winter on the macrotidal Sinduri beach in Taean, and to understand the processes their formation and subsequent flattening. Beach profiling has been conducted regularly over the last four years using a VRS-GPS system. Surface sediment samples were collected seasonally along the transectline, and grain size analyses were performed. Tidal current data were acquired using a TIDOS current observation system during both winter and summer. The Sinduri macrotidal beach consists of two geomorphic units: an upper high-gradient beach face and a lower gentler sloped intertidal zone. High berms and beach cusps did not develop on this beach face. The approximately 400-m-wide intertidal zone comprises distinct 2-5 lines of multiple bars. Mean grain sizes of sand bars range from 2.0 to 2.75 phi, corresponding to fine sands. Mean sizes show shoreward coarsening trend. Regular beach-profiling survey revealed that the summer profile has a multi-barred morphology with a maximum of five bar lines, whereas, the winter profile has a non-barred, flat morphology. The non-barred winter profiles likely result from flattening by scour-and-fill processes during winter. The growth of multiple bars in summer is interpreted to be formed by a break-point mechanism associated with moderate waves and the translation of tide levels, rather than the standing wave hypothesis, which is stationary at high tide. The break-point hypothesis for multi-bars is supported by the presence of the largest bar at mean sea-level, shorter bar spacing toward the shore, irregular bar spacing, strong asymmetry of bars, and the 10-30 m shoreward migration of multi-bars.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.243-255
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• 2014

This study was investigated to estimate the relations between benthic environments and benthic polychaetous community from April 2012 to February 2013. Twenty four stations were selected sequentially with Seomjin River Estuary from the northern part of Gwangyang Bay. The study area could be divided into three characteristic zones based on salinity, water temperature, dissolved oxygen and pH such as Saline Water Zone (SWZ), Brackish Water Zone (BWZ), and Fresh Water Zone (FWZ). Salinity was above 30.0 psu in SWZ, drastically decreased toward inland in BWZ, and nearly zero psu in FWZ. SWZ showed its specific environmental characters like that water temperature fluctuated with little seasonal change and DO showed the lowest values among three zones, and pH maintained as consistent value without seasonal fluctuation. In FWZ, on the other hand, water temperature showed high seasonal fluctuation, DO showed the highest values among three zones, and pH fluctuated greatly. In sedimentary environment, mud, sand and sand/gravel were found as dominant sedimentary deposits in SWZ, BWZ and FWZ, respectively. Organic matter content and AVS in surface sediment were high in SWZ, while Chl-a content high in FWZ. This study area showed a marked environmental difference between FWZ and SWZ as follows: FWZ has coarse sediment and low salinity, low organic matter content, low AVS in FWZ but SWZ has fine sediment and high salinity, high organic matter content and AVS. Species number and mean density of benthic polychaete community was highest in Saline Water Zone (SWZ), drastically decreased in Brackish Water Zone (BWZ), and lowest in Fresh Water Zone (FWZ). Dominant polychates above 5.0% of individual numbers were 6 taxa. Lumbrineris longifolia, Prionospio cirrifera, Tharyx sp. occurred as main dominant species of all study periods, and Hediste sp., Praxillella affinis, Tylorrhynchus sp. dominantly occurred at some seasons. Inhabiting areas of dominant species were separated characteristically. Representative species in SWZ were Lumbrineris longifolia, Tharyx sp., Mediomastus sp.. Wide-appearing species between SWZ and BWZ were Prionospio cirrifera, Heteromastus filiformis, Aricidea sp.. Characteristic species in FWZ were Tylorrhynchus sp. and Hediste sp.. As the results of cluster analysis and nMDS based on the species composition of polychaetous community, unique station groups were established in SWZ and FWZ. Stations in BWZ were sub-divided into several groups with season. Pearson's correlation analysis and PCA between benthic environments and ecological characteristics of polychaetous community showed that salinity, sediment composition, organic content and dissolved oxygen played a role to determine the temporal and spatial distribution of the ecological characteristics as species number, mean density, abundance of main species, and ecological indices.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.4
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• pp.179-187
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• 1980

1) Soils (volcanic ash and muck) were fractionated into particle-size separates (200 - 20, 20 - 2, 2 - 0.5 and finer than $0.5{\mu}$ in diamter), and of which the silt fraction was further fractionated into specific gravity separates (more than 2.0, 2.0 - 1.7, 1.7 - 1.4 and less than 1.4 in $g/cc^3$). And total organic and inorganic phosphorus in the separates were determined. 2) The amounts of total, organic and inorganic phosphorus distributed in the particle-size separates were as follows fine clay > coarse clay > silt > fine sand fraction. The increase rate in the amounts of phosphorus was great in the separates finer than $20{\mu}$, and greatest in the fine clay fraction. 3) The amounts of total, oganic and inorganic phosphorus distributed in the specific gravity separates were as follows: 2.0 - 1.7 > 1.7 - 1.4 > heavier than 2.0 fraction. The increase rate in the amounts of phosphorus was in the following order 2.0 - 1.7 > 1.7 - 1.4 > heavier than 2.0 fraction. 4) Distribution of carbon, amorphous aluminum and free iron oxides in the particle-size separates and the specific gravity separates were examined, and the distribution and the formes of organo-minera1 complexes in the separates were discussed to shed light on the factors affecting the distribution of phosphorous into the separates. And it was estimated that there was close relation among the distribution of organic and inorganic phosphorus, and the distribution and the formes of organo-minera1 complexes.

• Journal of the Korean Geotechnical Society
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• v.32 no.7
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• pp.25-34
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• 2016

Recently, in Korea, problems related with unstability of slope or sinkhole in urban area due to erosion of compacted granite soil which was used as a backfill or embankment material have been treated as important issues. Small hole might develop inside of backfill area due to erosion of not only weathered granite soil but also clay, silt, fine sand size particles when underground water flows. Once erosion starts in a soil mass, erosion rate increases gradually to cause rapid destruction. In this study, a rotating cylinder test (RCT) was performed to evaluate the hydraulic resistance characteristics of compacted weathered granite soil under various relative densities and preconsolidation pressures. Meanwhile, an image analysis method was introduced to analyze radius of irregularly eroded sample. It was found that image analysis is an effective means of minimizing the error in calculating a critical shear stress and threshold shear stress on the irregularly eroded sample. Furthermore, in general, hydraulic resistance capacity increases with the increase of relative density and preconsolidation pressure.

• Journal of the Korea Concrete Institute
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• v.14 no.5
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• pp.789-795
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• 2002

To evaluate the bind rate and behavior of two types chloride ion-one is the chloride ion added in mixture when un-washed sea sand is used as fine aggregate, one is the chloride ion admitted in the new version of concrete standard specification, pore solution extracted in cement paste were analyzed. The results are follow. 1 As passing the time, the chloride concentration in the pore solution decreases with the Increase in the chloride content absorbed by the hydrate products. As compared with chloride contents in mixing water, the bound ratio of chloride at 49 days is 64∼90％. 2. The bound ratio of chloride in cement paste considering evaporable water as pore solution is obtained. In case of Pl∼P3(added chloride content wt of cement 0.046∼0.16 ％), the bound ratio of chloride is 91.8∼93.5 ％. P4(added chloride wt of cement 0.3％) is 89.1％, but P5(added chloride wt of cement 0.617％) bound is only 77％. 3. The bound ratio of chloride to wt of cement is 0.015∼0.475％ with adding chloride. In case chloride added over 0.091 ％ wt of cement, the bound chloride content increases 1.7∼1.8 times in spite of added chloride increase twice. The bound ratio of chloride to wt of cement decreased with the increase in the chloride content. 4. The more increase added chloride content, the more increase the bound ration of chloride. But the absolute value of chloride content in pore solution increased.