• Economic and Environmental Geology
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• v.47 no.2
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• pp.147-168
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• 2014

The soil geochemical exploration was carried out targeting around Tri Le area far from about 30 km with northwestern direction from Que Phong within Nghe An province. The interval of sampling are horizontal 200 m interval with 23 line and longitudinal 300 m with 10 line, resulting in 228 soil samples. Based on the result of the soil geochemical exploration, the detailed pitting survey was carried out targeting the grid point with high TREO content, resulting in 75 soil samples within 7 pits. The geology of survey area are consisted of Ban Chieng biotite granite complex and granitic gneiss intruding Ban Khang formation comprising of quartz schist and marble. Main mineralization in the study area have the characteristics of occurrence with tin, ruby and REE-bearing monazite and xenotime to be thought as occurring at the alteration zone of granite complex. In order to elucidate the source rock of monazite and xenotime confirmed from heavy sand, soil geochemical exploration was carried out. As a analysis result with ICP-MS on the soil samples from the soil geochemical exploration, total REE oxide content of background amount to about 2 times of crustal abundance, enriching the heavy rare earth(about 2 times) and light rare earth(about 1.5 times). As a analysis result with ICP-MS on the soil samples from the soil detailed pit survey, we only identified outcrop considering as economic weathered granite body at the grid point 1-10 pit among 7 pits. As a synthetic consideration on the soil geochemical exploration and detailed pit survey, we tentatively designated Tri Le area as no promising target for REE. In 2014, we have the plan to carry out the soil geochemical exploration targeting the extended economic REE ore body in Quy Chau as project area from 2011 to 2012.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.344-353
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• 2020

Plants native in Korea have not only ornamental values but also have excellent environmental adaptability, so they can be used as garden plants. Studies on proper volumetric water content (VWC) of substrates have been reported, but many have been conducted in glasshouse conditions where environmental factors were controlled. When considering garden planting, it is necessary to perform the automated irrigation system in outdoor conditions where rainfall occurs at frequent intervals. This research aimed to investigate the VWC suitable for the growth of Minuartia laricina, Arenaria juncea, and Corydalis speciosa in open filed. Sandy soil which consisted of particles of weathered rock was used, and the VWC of 0.15, 0.20, 0.25, and 0.30 ㎥·m^-3 was maintained using an automated irrigation system with capacitance soil moisture sensors and a data logger. No significant differences in growth and antioxidant enzymes activity of A. juncea were observed among VWC treatments. However, the survival rate was low at VWC 0.30 ㎥·m^-3 treatment, which was the highest soil moisture content. Even considering the efficiency of water use, we recommended that VWC 0.15-0.20 ㎥·m^-3 is suitable for the cultivation of A. juncea. Minuartia laricina showed better growth with lower VWC. Because of frequent rainfall in open field, plant volume and survival rate was high even in VWC 0.15 ㎥·m^-3 treatment. In C. speciosa, the plant height, number of shoots and lateral shoots, and fresh and dry weight were higher in plants grown in VWC 0.25 ㎥·m^-3 as compared with that in the plants grown at 0.15, 0.20, and 0.30 ㎥·m^-3. Based on these results, M. laricina needed less water in open filed, and A. juncea and C. speciosa required higher VWC, but excessive water should be avoided.

• Journal of Conservation Science
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• v.24
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• pp.23-36
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• 2008

The stone Buddhas and Shrine of Unjusa temple (Korea Treasure No. 797) in Hwasun formed in Koryo Dynasty are unique style which the Buddha faces each other the back parts of south and north within the stone Shrine. The stone Buddhas and Shrine are highly evaluated in historical, artistic and academic respects. But, the stone properties have been exposed in the open system various aspects of degradations weathered for a long time without specific protective facilities. The rock materials of the stone Buddhas and Shrine are about 47 blocks, and total press load is about 56.6 metric ton. The host rocks composed mainly of white grey hyaline lithic tuff and rhyolitic tuff breccia. In addition, biotite granite used as part during the restoration works. The chemical index of alteration for host tuffaceous rocks and the replacement granites range from 52.1 to 59.4 and 50.0 to 51.0, respectively. Weathering types for the stone Buddhas and Shrine were largely divided with physical, chemical and biological weathering to make a synthetic deterioration map according to aspects of damage, and estimate share as compared with surface area. Whole deterioration degrees are represented that physical weathering appeared exfoliation. Chemical weathering is black coloration and biological weathering of grey lichen, which show each lighly deterioration degrees. According to deterioration degree by direction of stone Buddhas and Shrine, physical weathering mostly appeared by 39.1% on the sorthern part, and chemical weathering is 61.2% high share on the western part. Biological weathering showed 38.3% the largest distribution on the southern part. Therefore, it is necessary to try hardening for the parts with serious cracks or exfoliations, remove secondary contaminants and organisms through regular cleaning. Also necessary to make a plan to remove moisture of the ground which causes weathering, and estimate that need established and scientific processing through clinical demonstration of conservation plan that chooses suitable treatment.

• Conservation Science in Museum
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• v.19
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• pp.1-18
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• 2018

The Stele for National Preceptor Hongbeop from the Jeongtosa Temple site in Chungju is one of the most important stone cultural heritage items for exemplifying the style of the Goryeo era. Despite its obvious value, this relic has been stored in a weathered condition at the National Museum of Korea. It had suffered various dismantling and displacements during the Japanese colonial period and had long been exposed in the open air. The stele was selected as a subject for the Stone Monuments Restoration Project launched by the National Museum of Korea in 2015. In preparation for its outdoor exhibition as part of the restoration project, this study investigated the characteristics of its materials, produced a map of its deterioration from weathering, and carried out ultrasonic analysis of the materials to provide findings useful for conservation treatment. The materials analysis revealed that the turtle-shaped pedestal of the stele was made from two-mica granite consisting of medium-grained quartz, plagioclase, alkali feldspar, biotite, and muscovite. Its body stone is crystalline marble, the rock-forming mineral in which is medium-grained calcite in a rose-pink color with dark grey spots. The dragon top of the stele is made of crystalline marble, the major component of which is medium-grained calcite of a light-grey color. The deterioration consists of 21.5% abrasion on the stone body, with its south face most damaged, and 18.6% granular disintegration, with the north face most damaged. The ultrasonic material characterization conducted for mapping the general condition of weathering shows low values on the parts-assembly area of the turtle-shaped pedestal and on the upper portion of the stone body. It is considered that there is dislocation due to partial blistering and fracturing as well as to the differences in surface treatment. Prior to the outdoor exhibition of the stele, the surface was cleaned of contaminants and was consolidated based on the scientific investigation in order to prevent weathering from the external environment.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.85-92
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• 2015

This study examined the settlement of a 1-2W type greenhouse using a timber pile, which was recently established on Gyehwa-do reclaimed land, in order to obtain base data for the construction of a greenhouse on reclaimed land. The results of this study are as follows. foundation and timber pile increased over time, irrespective of the interior and exterior of the upon investigation of the ground, it was confirmed that there was no soft rock stratum (bedrock), and that a sedimentary stratum existed under the fill deposit, which is estimated to have been reclaimed during the site renovation. It was also found that a weathered zone was located under the fill deposit and sedimentary stratum, and that the soil texture of the entire ground floor consisted of clay mixed with sand, silty clay, and granite gneiss, in that order, regardless of boreholes. In addition, the underground water level was 0.3m below ground, regardless of boreholes. Despite a slight difference, the settlement of the greenhouse or measurement sites (channels). With regard to the pillar inside the greenhouse, except in the case of CH-2, the data at a site located on the side wall of the greenhouse (wind barrier side) indicated vibrations of relatively larger amplitude. Moreover, the settlement showed a significant increase during a certain period, which was subsequently somewhat reversed. Based on these phenomena, it was verified that the settlement range of each site in the interior and exterior of the greenhouse was between 1.0 and 7.5mm at this time, except in the case of CH-1. The results of the regression analysis indicated good correlation, with the coefficient of determination by site ranging between 0.6362 and 0.9340. Furthermore, the coefficient of determination ranged between 0.6046 and 0.8822 on the exterior of the greenhouse, which is lower than inside the greenhouse, but still indicates significant correlation.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.1
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• pp.42-50
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• 2009

Samples of subway dust were collected by the air filter system of 30 subway stations on Daegu subway line 1 in January 2008. Samples were sieved below 100 ${\mu}m$, and 14 elements were analyzed using ICP after acid extraction. Results obtained from the source assessment of trace elements using enrichment factor showed that Ca, Fe, K, Mg, Mn, Na, V were influenced by natural sources such as weathered rock and resuspended soil, while Cd, Cr, Cu, Ni, Pb and Zn were influenced by anthropogenic sources such as fuel combustion and waste incineration. Concentrations were remarkably higher in components from natural sources than in components from anthropogenic sources. Anthropogenic sources were significantly affected by indoor dusts than outdoor dusts. Results of pollution indices of heavy metals indicated that indoor dusts were more contaminated with heavy metal ions than outdoor dusts. The correlation analysis among trace elements indicated that components were much correlated in the order of natural sources-anthropogenic sources, anthropogenic sources-anthropogenic sources, natural sources-natural sources in both indoor and outdoor dusts. Trace element components of outdoor dusts were largely correlated than those of indoor dusts. In addition, indoor dusts were significantly affected by outdoor dusts rather than depth from the surface or the average daily number of subway passengers.

• Korean Journal of Heritage: History & Science
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• v.50 no.4
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• pp.122-147
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• 2017

The Jungsandong sites are distributed across quartz and mica schist formations in Precambrian, and weathering layers include large amounts of non-plastic minerals such as mica, quartz, felspar, amphibole, chlorite and so on, which form the ground of the site. Neolithic pottery from Jungsandong exhibits various brown colors, and black core is developed along the inner part for some samples, and sharp comb-pattern and hand pressure marks can be observed. Their non-plastic particles have various composition, size distribution, sorting and roundness, so they are classified into four types by their characteristic mineral compositions. I-type (feldspar pottery) is including feldspar as the pain component or mica and quartz. II-type (mica pottery) is the combination of chloritized mica, talc, tremolite and diopside. III-type (talc pottery) is with a very small amount of quartz and mica. IV-type (asbestos pottery) is containing tremolite and a very small amount of talc. The inner and outer colors of Jungsandong pottery are somewhat heterogeneous. I-type pottery group shows differences in red and yellow degree, depending on the content of feldspar, and is similar to III-type pottery. II-type is similar to IV-type, because its red degree is somewhat high. The soil of the site is higher in red and yellow degree than pottery from it. The magnetic susceptibility has very wide range of 0.088 to 7.360(${\times}10^{-3}$ SI unit), but is differentiated according to minerals, main components in each type. The ranges of bulk density and absorption ratio of pottery seem to be 1.6 to 1.7 and 13.1 to 26.0%, respectively. Each type of pottery shows distinct section difference, as porosity and absorption ratio increase in the order as follows: I-type (organic matter fixed sample) < III-type and IV-type < I-type < II-type (including IV-type of IJP-15). The reason is that differences in physical property occur according to kind and size of non-plastic particles. Although Jungsandong pottery consists of mixtures of various materials, the site pottery has a geological condition on which all mineral composition of Jungsandong pottery can be provided. There, it is thought that raw materials can be supplied from weathered zone of quartz and mica schist, around the site. However, different constituent minerals, size and rock fragments are shown, suggesting the possibility that there can be more raw material pits. Thus, it is estimated that there may be difference in clay and weathering degree.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.1
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• pp.57-70
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• 2009

Considerable advance has been made on research on effect of steel pipe Umbrella Arch Method (UAM) and mechanical reinforcement mechanism through numerical analyses and experiments. Due to long analysis time of three-dimensional analysis and its complexity, un-quantitative two-dimensional analysis is dominantly used in the design and application, where equivalent material properties of UAM reinforced area and ground are used, For this reason, development of reasonable, theoretical, quantitative and easy to use design and analysis method is required. In this study, both field UAM tests and laboratory tests were performed in the residual soil to highly weathered rock; field tests to observe the range of reinforcement, and laboratory tests to investigate the change of material properties between prior to and after UAM reinforcement. It has been observed that the increase in material property of neighboring ground is negligible, and that only stiffness of steel pipe and cement column formed inside the steel pipe and the gap between steel pipe and borehole contributes to ground reinforcement. Based on these results and concept of Convergence Confinement Method (CCM), two dimensional axisymmetric analyses have been performed to obtain the longitudinal displacement profile (LDP) corresponding to arching effect of tunnel face, UAM effect and effect of supports. In addition, modified load distribution method in two dimensional plane-strain analysis has been suggested, in which effect of UAM is transformed to internal pressure and modified load distribution ratios are suggested. Comparison between the modified method and conventional method shows that larger displacement occur in the conventional method than that in the modified method although it may be different depending on ground condition, depth and size of tunnel, types of steel pipe and initial stress state. Consequently, it can be concluded that the effect of UAM as a beam in a longitudinal direction is not considered properly in the conventional method.