• Economic and Environmental Geology
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• v.33 no.3
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• pp.195-204
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• 2000

order to investigate physical characteristics and element concentrations of sediments, coastal bottom sediments were collected at 20 stations in the vicinity of Youngkwang Nuclear Power Plant. After air drying of samples in the laboratory. article size distribution was examined by Master sizer (X-350F), radio-activity by HPGe ${\gamma}$-spectrphotometer, and element concentrations by ICP-AES and AAS. According to particle size analysis , sediments are mainly composed of silt fraction weith 23% of sand, 65% of silt and 12% of clay on average. Most sediments are derived from muddy environment that silt dominates with the characteristics of 5.3${\varsigma}$ mean particle size, poorly sorted, very fine skewed and lepto-kurtic. Only two sediments are well sorted with sandy silt owing to wind, winnowing action, tide and current andits complex reactions. Element concentrations in the coastal bottom sediments are relatively high at finer sediment and show significant relationship with grain size. Index of geoaccumulation by heavy metals at every sampling station is classified as practically unpolluted. The radioactivities of the sediments were measured for 15 isotope elements, and 2 elements of K-40 and Cs-137 were detected in most sediments. The K-40 is the natural nuclide and the artificial nuclide of Cs-137 was thought to be derived from the fallout of past nuclear weapon test. The results of correlation coefficient between grain size and radioactivity shows that the activity of Cs-137 significantly increases in finer grain.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.290-295
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• 1993

To evaluate rice yield and changes of soil properties, 3 tillage methods including no tillage was tested in different soil textures, such as silty clay, sandy loam and silt loam fields. Hwaseongbyeo was transplanted by machine at May 28. Water and soil temperature of no tillage were lower than other plots, but differences of temperature were not larger in different treatments. Mean water requirement in depth of sandy loam field was larger than other textures, but that of silty clay field was smaller. The water requirement in depth of no tillage was larger by 1.4～2.2mm / day than the other plots. In the silty clay field, mineral contents, except Na$_2$O content, of rice plant of no tillage plot at the harvesting stage was higher than the other treatments. The rice yields in the no tillage plot were decreased by 18% in sandy loam, by 7% in silty clay and by 1% in silt loam respectively than the power tiller plots.

• Journal of Conservation Science
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• v.18 s.18
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• pp.51-62
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• 2006

This study, in order to do a nondestructive research on the mural walls kept in the protective house in Muwisa Temple, Kangjin, took four examinations; particle size analysis, XRD analysis, ultrasonic investigation, and thermo-infrared investigation. Component ratio of mural wall varied; clay of wall bodies consisted of gravel of 1.78 g, sand of 5.39 g, silt of 4.91 g and clay of 6.26 g. Ultrasonic velocity and one-axis compression strength tests done with eight mural-painted walls yield results as follows; the value of ultrasonic velocity ranged between 71.63 and 3610.11 m/s with the average of 417.44 m/s and on-axis compression strength ranged between 70.34 and $533.28kg/cm^2$ with the average of $83.23kg/cm^2$. The value increased in the order of Bosaldo(No.6)

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1178-1178
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• 2005

• Journal of The Geomorphological Association of Korea
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• v.19 no.3
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• pp.23-36
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• 2012

This study aims to think about the problem of dolmens: the reasons for the presence of dolmens and how to construct it, at the point of view of geographical and geomorphological. The subjects of this study is the dolmens which locate between at Dogok Hyosanri and Chunyang Daesinri Hwasoon-gun, Jeonlanamdo. The study areas in Hyosanri, Daesinri has been observed as follows. First, the long axis direction of Dolmen upper stone and the slope one are the same. Second, tor, block stream, hockey stick, etc. Third, Composition of the soil silt> sand> clay is distributed in the order. Forth, The soil of high quality silt and the roundness of angular, sub-angular-level and the high frequency, peaks of quarts and illite clay minerals show. Fifth, in the result of $SiO_2/Al_2O_3$, $SiO_2/R_2O_3$, and CIA(Chemical Index of Alteration), Hyosanri, Daesinri areas show mechanical weathering was dominant and chemical weathering environment was not being progressed. The blocks used in construction of dolmens had moved to the bottom of slopes by mass movement such as solifluction then them which had been placed in the position seem to be used by people of Bronze. Based on the above results, the process of construction of dolmens can be estimated as follows. They would dig up the ground under the upper stone of dolmens, put the supporting stone in the place, then dig up earth, place into remains, close the obturating stones, then heal up earth.

• Journal of the Korean Geosynthetics Society
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• v.18 no.1
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• pp.1-9
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• 2019

This study investigated settlement and scouring characteristics of artificial reef reinforced with various reinforcement types to reduce settlement and scouring. Three reinforcement types were prepared: geogrid, geogrid-bamboo mat (GBM) and seaweed-pile mat (SPM). Various laboratory tests such as bearing capacity test, large size settlement test, two-dimensional flow scour test were performed according to different soil types (sand, silt, clay). Laboratory test results indicated that bearing capacity of seabed with a reinforced artificial reef increased and its settlement and scour depth reduced for all reinforcement types. Especially, reinforcement effect tends to be greater in clay soft ground rather than sand and silt grounds.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.2
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• pp.143-150
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• 1993

Shallow sub-bottom reflection recorders are obtained using dual frequency (15/100 KHz). The main goal of this study is to enhance the resolving power and penetration for the sub-bottom reflection of the sub-marine seismic exploration. The Fresnel zones of spherical waves for the near-field are of great importance to reach the high resoluton. In case a target to detects than the Fresnel radius, a diffraction hyperbola on the recorder is observed. A larger attenuation of sand makes less penetration than the smaller attenuation of silt and clay. It is found that the selective frequency as well as the seismic energy generation is the most important factors for sub-marine exploration. This technique of using dual frequency sub-marine exploration may be applied to detect the sub-bottom sludge soil, ocean contamination and marine archaeological relics.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.212-217
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• 1984

Spatial variabilities of particle size distribution of 96 samples from Hwadong SiCL and Jungdong Sl were studied by using geostatistical concepts. The measurement was made at the nodes of the regular grid consisting of 12 rows and 8 columns. Sample spacing within rows and columns was 3 and 2 meters, respectively. The results are summarized as follows. 1. Variograms of Hwadong SiCL were fitted for the linear model and those of Jungdong SL for the spherical model. 2. Variograms of properties for Hwadong and clay for Jungdong showed the pure nugget effect. Those of silt and clay for Jungdong, however, appeared the nugget effect. 3. The minimum number of samples necessary to reproduce results similar to the true mean of the 96 measured values was approximately estimated. The minimum sample sizes of silt, clay, and sand in Hwadong SiCL were 27, 13, and 6, respectively. And the minimum sample size of clay in Jungdong SL was 17. 4. The approximate number of samples required to detect the difference of 5% of the true mean with 0.95 confidence level was estimated. The resulting number of samples for silt and sand in Jungdong was 14, and 26, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.916-921
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• 2011

This study was carry out on a Jang-Won series (fine loamy, mixed, mesic family of typic fragipan) that were established and classified as a fragipan soil in Korea. The morphological, physical, chemical and minerals characteristics of Jang-Won series were studied to determine the genesis of fragipan soils in natural environment. Each sample was analyzed for its physical, chemical and mineralogical characteristics. The particle size distribution of samples was measured using pipette method. Clay minerals were investigated on parallel-oriented specimens of the clay fraction ($<2{\mu}m$) from each horizon, separated by sieving and centrifugation, using X-ray diffraction (XRD) analysis. Micromorphological observations were made on thin sections prepared from soil blocks impregnated with Crystic Resin, cut and ground to less than $30{\mu}m$ in thickness, and finally polished with diamond paste. Most horizons have pH values in the range of fewer than 5.0 and have very low base-saturation values. Their textural classification ranges from silt loam to loam, the lower horizons being the finer. The clay fraction revealed the occurrence of illite, kaolinite, chlorite and vermiculite. The micro-morphological analysis carries out thin sections from each soil profile. The silt concentrations occur as extremely dense and homogenous bands or zones of silt-sized materials, brownish in colour in plane-polarized light and anisotropic in cross-polarized light, surrounding or adhering to skeleton grains. The genesis of fragipan in the Jangweon series assumed composition of clay fraction rather than silt concentration. Therefore, this results suggested an authentic interpretation which Jangweon series is classification as Typic Fragiochrepts.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.107-111
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• 2003

Estuary of Nakdong river area is composed of unconsolidated sediments including clays that are deposited varying from 40 to 70m thick. The purpose of research is the knowledge of the correlation between engineering properties and mineralogy of clay sediments. The correlation analysis carry out multiple regression that have independent variables (Engineering properties) and dependent variables (mineralogy, geochemistry). Engineering properties of clay are correlated with the mineral compositions and geochemical characteristics. The result of the analysis is Wn=-0.6 Feldspar ＋ 1.1 pH ＋ 0.01 TDS ＋ 27.5, Ip=0.36 Clay ＋ 1.44 Vermiculite ＋ 0.94 clay mineral-22.88, P$_{L}$=0.005 TDS - 0.31 Feldspar ＋ 22.43, e$_{o}$=0.02 Vermiculite - 0.01 Quartz ＋ TDS ＋ 0.93, E$_{50}$=1.94 Vermiculite-0.96 Kaolinite -0.53 silt ＋ 49.64, SR=-0.25 Kaolinite ＋ 1.5 pH - 2.3 Conductivity, CC = 0.03 pH ＋ TDS - 0.2, LL = 0.5 Clay ＋ 1.3 Vermiculite ＋ 5.5 Conductivity ＋ 0.8 Caly mineral-20.4.4.4.4