• Economic and Environmental Geology
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• v.52 no.6
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• pp.617-626
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• 2019

In this study, we investigated the petrographic characteristics and physical property of the Rock-carved Seated Buddha at Bugmireugam hermitage of Daeheungsa temple in Haenam. The Buddha Statue was carved on micrographic granite, and the rock was composed of the fine quartz encircled by orthoclase. The results of diagnosis for deterioration evaluation have shown a highly damage rate of black contaminants (8.4%) and crack index (6.6). The ultrasonic velocity have detected SW (slightly weathered) grade of weathering coefficient (mean 0.18). Various weathering factor on the surface of the Buddha Statue was affected by precious shelter, and physical property with ultrasonic was directly influenced by the structural characteristics and fissure of host rock.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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• pp.41-49
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• 2014

The research was performed to investigate the weathering characteristics of fruit growth paper bags. The bags were used to cover fruits such as grapes and pears. And then they were collected after 30 and 60 days exposure at the orchard. The physical and optical properties of the bags tended to decrease with the exposure times. The larger change on the properties were found on the papers exposed for 30 days. The cover paper for pear showed the largest density changes. The air permeability were decreased with the exposure time in all bags. The cover paper for pear showed the very low values of air permeability. The mechanical properties of the fruit bags showed to be gradually decreased with the length of exposure time. The tear index showed the largest differences. The cover paper for pear showed the rapid decrease on the mechanical properties after 60 days of the exposure. The inner paper, however, showed the strength enough to cover the fruits. The precipitation showed more effect on the degradation of fruit growth paper bags than the light hours.

• The Journal of Engineering Geology
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• v.31 no.4
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• pp.731-739
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• 2021

This research aimed to analyze the characteristics of topsoil for soil conservation and promote the process of turning subsoil into topsoil. The physicochemical characteristics of topsoil and subsoil of different types of soil were compared, and their quantitative differences were examined. 204 soil samples were collected from a total of 102 areas according to rock types. These samples were tested to measure grain size, water content, and unit weight, along with XRF and XRD analyses. The topsoil and subsoil of the soil samples were also analyzed. The results of this research showed that the topsoil and subsoil had different physical characteristics, and that the chemical alteration index of the topsoil was higher than that of the subsoil. This would imply that the topsoil was high in clay minerals since it was directly affected by weathering more than the subsoil. In particular, vermiculite, one of the final products generated from weathering, was common in the topsoil.

• Journal of the Korean Geophysical Society
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• v.5 no.3
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• pp.199-209
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• 2002

We have carried out a nondestructive close examination for the purpose of the structural safety diagnosis of the Dabo Pagoda of Bulkuk temple located in Kyungju, Kyungbuk Korea. For estimating the mechanical properties of each rock block of the pagoda, ultrasonic measurements were conducted at 641 points of 255 blocks. The P-wave velocity ranges from 584m/sec through 5,169m/sec, and averages 2,901m/sec Based on this result, the uniaxial compressive strength was estimated to be $93{\sim}1,943kg/cm^2\;with\;396kg/cm^2$ of average, and the index of weathering is $0.07{\sim}0.88$ with 0.43 of average, which means the moderate degree of weathering. The comparison of the rock strength of each block with the overburden acting on the block reveals that the rock blocks related to the structure of the pagoda are relatively sound for uniform stress, but it is highly possible for a concentrated stress to lead to a partial failure. We suggest a monitoring of cracks due to the concentrated stress. The parapets of 1st and 2nd floors composed of small rock pieces are severely weathered. However, this is not directly related to the structural safety of the pagoda.

• Journal of The Geomorphological Association of Korea
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• v.19 no.1
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• pp.57-68
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• 2012

Red saprolites are appeared in granitic hills in Naju, Southern Korean Peninsula. These red saprolites were analyzed for their geochemistry, including CIA, A-CN-K and A-CNK-FM ternary plots, to understand the chemical weathering trend and rubefaction of the saprolites. These saprolites were compared with kaolinitic saprolites of Guadalquivir Basin in Spain formed under paleo-humid tropical conditions. Chemical Index of Alteration(CIA) value for Naju in Korea is 80, and 87 in Guadalquivir, suggesting moderate and strong weathering in both. Relative to kaolinitic saprolite of Guadalquivir in Spain, red saprolites in Naju are commonly weak loss of CaO, $Na_2O$, especially in $K_2O$. The A-CNK-FM ternary plots of Naju saprolites relative to Kaolinitic saprolites of Guadalquivir shows weak chemical alteration owing to slow removal of $K_2O$, but high mafic constituents, $Fe_2O_3$ and MgO, for most of the samples. In the saprolites of Naju, mafic oxides, $Fe_2O_3$ and MgO, become enriched because of the fast and massive removal of CaO, $Na_2O$ and $K_2O$ relative to other elements, resulting in rubefaction of the surface layer of the saprolites, so more redness than kaolinitic saprolites of Guadalquivir. It is found that the rubefaction of the saprolites is not necessarily proportional to chemical weathering intensity.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.1
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• pp.63-74
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• 2007

Unexpected ground conditions have always been a major problem for the construction of tunnel. Therefore, it is necessary to evaluate the risk capacity before and/or during construction of new tunnel. This paper presents the simplified risk assessment system using modified stability number (N), namely Underground Risk Index (URI) system, to evaluate the tunnel risk possibility in the design stage. URI is a scoring system for risk possibility by rating the each appraisal elements. The modified stability number (N) which is one of risk factor in the Interaction Matrix parameters such as RQD, UCS, weathering, overburden, stability number, ground water-table, RMR, permeability and so on, is used in the system. In addition, the case study is performed in order to verify the applicability of URI-system in practice.

• 보존과학연구
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• s.27
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• pp.43-61
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• 2006

In this study stone heritages of 533 which is to be investigated through the five years for national treasures and treasures from 2001 to 2005 have been analyzed by statistics for types of stone heritages and rocks, level of alteration in order to make full use of guiding principle in conservation management of stone heritages. The ratio of stone pagoda as a percentage of 34.5% in the stone heritages much higher than others and that is composed of granite(83.0%) in the igneous rock. In the weathering index of surface, a 37.5% of the national treasures were classified with the level 4 and46.3% of the treasure were the level 3 according to state. The present condition of organism distribution take up 30.6% for the level 3 and 22.1% for level 1. In structural stability index, a 40.6%of the national treasures and a 54.2% of treasure were ranked level 3.

• Journal of the Korean Applied Science and Technology
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• v.23 no.3
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• pp.264-271
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• 2006

PU type flame-retardant coatings (TBAO/L-75, TBAOL ; TBAO/N-100, TBAON) were prepared by blending bromine-containing modified polyester (TBAO) which was synthesized in our earlier work. with two kinds of isocyanate curing agents, Desmodur L-75 and Desmodur N-100. Physical properties of the prepared flame-retardant coatings were tested. TBAOL shows better hardness than TBAON, while TBAON shows better viscosity, accelerated weathering resistance, yellowness index and lightness index difference than TBAOL. There were no remarkable differences in fineness of grind, $60^{\circ}$ specular gloss, cross-hatch adhesion, and abrasion resistance of TBAOL and TBAON. There was no discernable difference in flame-retardancy between the two flame-retardant coatings, TBAOL and TBAON. When the content of tribromo acetic acid, which is flame-retarding component, was 30wt% the LOI value was in a range of $29{\sim}30%$, which indicates that the two coatings are good flame-retardant coatings.

• Asian Journal of Atmospheric Environment
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• v.6 no.2
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• pp.118-126
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• 2012

To investigate the effect of aircraft traffic emissions on soil pollution, metal levels were analyzed for 8 metals (Fe, Cr, Pb, Zn, Cu, Ni, Mn and Cd) from the vicinity of the Indira Gandhi International (IGI) airport in Delhi, India. The texture of the airport soil was observed to be sandy. Among the metals, Cd showed minimum concentration ($2.07{\mu}g\;g^{-1}$), while Fe showed maximum concentration ($4379{\mu}g\;g^{-1}$). The highest metal accumulation was observed at the landing site. Significant correlations were observed between metals and different textures (sand, silt, and clay) as well as with organic carbon (OC). The results indicate that grain size play a major role in OC retention in soil and subsequently helps in adsorption of metals in soil. M$\ddot{u}$ller's geoaccumulation index (I-geo) showed that airport soil was contaminated due to Cd and Pb with the pollution class 2 and 1, respectively. Pollution load index of the airport site was 1.34-3 times higher than the background site. The results of factor analysis suggested that source of the soil metal is mainly from natural weathering of soil, aircraft exhaust, and automobile exhaust from near by area. With respect to Dutch target values, the airport soils showed ~3 times higher Cd concentration. The study highlighted the future risk of enhanced metal pollution with respect to Cd and Pb due to aircraft trafficking.

• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.590-596
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• 2014

Wooden cultural heritages of Korea have been destroyed by fire in many cases. As a result, a number of methods to protect wooden cultural properties against fire were introduced. A way of protecting wooden cultural properties installations of fire equipments such as sprinkler, fire alarm system, or fire extinguisher. Another way of protecting wooden cultural properties is to treat them with flame retardants for their safety. Development of a very effective flame retardant with a good performance without affecting danchung and wood quality is required. At the same time, methods of evaluating flame retardant treated woods should be devised to assess their efficacy. In this study, combustion characteristics using cone-calorimeter, limit oxygen index, moisture absorption, iron corrosive and weathering were analyzed to evaluate the flame resistance efficacy and performance of flame retardants treated woods. The evaluation methods of flame retardants for wooden cultural heritage were suggested.