• The Journal of the Petrological Society of Korea
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• v.26 no.2
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• pp.143-152
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• 2017

As weathering processes, micro-cavities are formed on the surface of rocks, and in particular, the porous structure is increased in feldspar. Adsorption and antibacterial tests were carried out to clarify the environmental function of porous feldspar porphyry. Almost all the heavy metals were adsorbed in the feldspar filter and the adsorption rate could be controlled by changing the filter length. The shake flask method of fabric coated with 5% and 7% feldspar powder showed very high antibacterial activity of 98% and 99.9%, respectively. The cation exchange capacity at a particle size of $10{\mu}m$ was 114.63 meq/100g probably due to the porous structure. The potential value of porous feldspar porphyry as a resource is sufficient based on the results of the experiment.

• Journal of the Mineralogical Society of Korea
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• v.26 no.4
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• pp.273-283
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• 2013

The artificial rain (pH 4.0, pH 5.6 and pH 6.85) and weathering simulation test are applied in dolomitic marble for the prediction of deterioration of the stone monuments constructed with carbonate rock by acid rain. pH of the applied rain all increase to about neutral pH after reaction of marble. The contents of $Ca^{2+}$ and $Mg^{2+}$ have increased more than twofold in two acid rain and deionized neutral rain after reaction of marble. The weight of marble is expected to decrease $0.00037kg/m^2$ each test cycle by pH 4.0 rain. This weight reduction rate of marble is 1.4 and 3.1 times more in pH 5.6 and pH 6.85 rain respectively, and 3.7 times more in only artificial weathering test. The compressive strength of marble is expected to decrease 0.2468, 0.1791 and $0.1280kg/m^2$ per test cycle with pH 4.0, pH 5.6 and pH 6.85 rain, respectively. These results mean that more acidic rain more enfeeble the strength of marble. Dolomite and small amount of calcite are precipitated in the rains after reaction of marble.

• Journal of the Korean association of regional geographers
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• v.23 no.1
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• pp.168-177
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• 2017

In order to reveal formation factors and developmental processes of tafoni this study was conducted with petrological analysis including microscopic observation, measurement of water content and water analysis at Golgulsa temple in Gyeongju, South Korea. The direction of the entrance to tafoni at Golgulsa temple tends to coincide with the direction of slope, and this is thought to be related to the direction of wind flow and water supply. Tafoni's initial developmental processes is judged to have grown as a result of a breakaway of rock fragments along with beddings and cracks in rock. Then, tafoni have been enlarged along at the spots that sufficiently accommodate water supply depending on the direction of wind. The results of water analysis of the stagnant water in gnamma implies that a high meltage of Na and Cl compared to other inland areas can be from the adjacent shore. The effects of such saline substances on rock weathering and development of taponi are currently under way through electronic microscopy and geochemical analysis.

• Journal of Conservation Science
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• v.28 no.1
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• pp.39-52
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• 2012

The Usuki Stone Buddha Statues in Oita are consisted of 60 Buddhas which represent of Japan carved on the rock-cliff in the 12 to 14th centuries. The basement rock of the statues is dark gray welded lapilli tuff that containing the Aso-4 pyroclastic rock group. Deterioration maps for the Hoki I and the Furuzono Buddha Statues group show multi-directional fissures on the Cakra, and sheeting-off zone at the margin of uprising water. Deterioration rate of the Hoki I group was calculated fissure about 121 in number, 19% of sheeting-off zone and 51% of biological weathering in surface of area. And the Furuzono group was also evaluated as about 48 of fissures in number, 24% of sheeting-off zone and 41% biological weathering. The slope stability assessment results, the Hoki I developed discontinuous planes has possibility of planar, toppling and wedge failures in all caves. Ultrasonic velocity of the Aizen-myooh (basement rock) ranges from 1,520 to 2,794 (average 2,298m/s). And pedestal of Amita-yeorae which has been replaced by new fresh rock is measured as 3,242 to 4,141 (average 3,813m/s). Therefore, we establish of planing conservation treatment and reinforcement methods to fissure, cavity, sheeting-off zone in the Buddha surface.

• Journal of Conservation Science
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• v.28 no.4
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• pp.329-341
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• 2012

Magai Wareiishi Jizo (Buddhist statue carved on rock surface) is close to shoreline and a part of rock block is periodically immersed by seawater. Rock material of the Wareiishi-jizo statue is composed mainly of medium or coarse-grained biotite granite and very durable. However, physical properties of the rock have been changed according to the complex interactions of the salt solution and surrounding environment. Exfoliation of the rock surface is a serious condition by salt crystallization. Exfoliation (14.6%) is concentrated on the upper part of the rock block with mainly boundary of seawater as the center. On the other hand, lower part of the rock block show black layers by contaminants deposition. In addition, brown discoloration and biological contaminants is overlapped. Rock surface show high discoloration rate of 50.5% (black discoloration, 29.2% > yellow discoloration, 14.1% > brown discoloration, 4.4% > green discoloration, 2.9%). Upper part of the rock block had a lot of change in the physical properties than lower part that is immersed by seawater. In particular, surface properties of the rock block was very weak state at the boundary surface of seawater permeation.

• Conservation Science in Museum
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• v.9
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• pp.59-66
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• 2008

At platform-reinforcing side stone plate having been exhibited in outdoor exhibition space of Gyeongju National Museum, split and exfoliation were proceeding due to weathering at joined·restored parts. Accordingly we checked imbibitional minerals in the stone through observation and analysis with polarized microscope, and studied capillary water absorption rate using Schmidt Hammer rebound hardness measurement and Karsten Tube.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.455-458
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• 2003

We investigated the leaching of elements from anthracite ashes by interactions with seawater. The results show that consumption rates of dissolved oxygen are 7.5 times greater in the seawater system than in the fresh water system and indicate that the differences in DO consumption rate may plat a role in regulating the element leaching from the coal ashes. It is revealed that seawater's pH buffering capacity is the most important factor that makes the leaching of elements and their chemical behaviors in the seawater system different from those in the fresh water environments. In overall, element leaching from the weathered ash is smaller than that from the fresh ash. However, the leaching of Si, Fe, Al, Mn, phosphate, and some other elements were independent of weathering. They were dependant only on the pH of the solutions.

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.316-324
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• 2001

To prepare an acrylic type pressure-sensitive adhesive, quarternary polymers were synthesized from butyl acrylate (BA), 2-ethyl hexyl acrylate (2-EHA), methyl methacrylate (MMA), and 2-hydroxy ethyl methacrylate (2-HEMA). The quarternary polymers were identified by FT-IR and Molecular weight was measured by Gel Pearmeation Chromatography. Also, viscosity, solid content and peel strength were examined. The peel strength was 160 $g_{f}/25$ mm when the volume ratio of feed monomer to solvent was 1.3:1, and the ratio was relevant to commercial usage. The pot life of adhesive was 30 sec at the 50 m/min of heat treatment rate at, and it indicated that the minimum drying time was 30 sec. In weathering resistance test, peel strength of $160{\sim}180$ $g_{f}/25$ mm after 1000 h, with no residual remains on the adhesive surface.

• Economic and Environmental Geology
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• v.33 no.5
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• pp.353-365
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• 2000

After their first appearance on Earth, bacteria have exerted significant influence on geochemical behavior of elements. Numerous evidence of their control on geochemistry through geologic history has been observed in a variety of natural environments. They have mediated weathering rate, formation of secondary minerals, redox transformation of metals and metalloids, and thus global cycling of elements. Such ability of bacteria receives so considerable attention from microbiologists, mineralogists, geologists, soil scientists, limnologists, oceanographers, and atmospheric scientists as well as geochemists that a new and interdisciplinary field of research called 'geomicrobiology' is currently expanding. Some recent subjects of geomicrobiology which are studied extensively are as follows: 1) Functional groups distributed on bacterial cell walls adsorb dissolved cations onto cell surfaces by electrostatic surface complexation, which is followed by hydrous mineral formation. 2) Dissimilatory metal reducing bacteria conserve energy to support growth by oxidation of organic matter coupled to reduction of some oxidized metals and/or metalloids. They can be effectively used in remediating environments contaminated with U, As, Se, and Cr. 3) Bacteria increase the rate of mineral dissolution by excreting proton and ligands such as organic acids into aqueous system. 4) Thorough investigation on the effects of biofilm on geochemical processes is needed, because most bacteria are adsorbed on solid substrates and form biofilms in natural settings.

• Corrosion Science and Technology
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• v.6 no.3
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• pp.120-127
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• 2007

In any developing nation major investment goes for infrastructure and it is not exception in India. Good numbers of buildings, bridges, shopping malls, car parks etc. are coming up with steel for sustainable development. Thus protecting the structures from corrosion are the challenges faced by professionals for all types of steel structures. About 3% of GDP is accounted for loss due to corrosion. To combat this up to date corrosion map is called for as the country has wide variation of climatic zones with vastcoastline. Logically organic paint system can be prescribed based on the corrosion rate on bare steel with respect to environment. Present paper will emphasis on the study conducted on two types of structural steel coated with organic paint located in twomarine environment having been exposed for three years, Test coupons made from steels both bare and coated are deployed at two field stations having marine (Digha) and industrial marine (Channai) environments. Various tests like AC impedance DC corrosion, polarisation, salt spray test, $SO_2$ chamber and Raman spectroscopy were carried out both in laboratory on fresh as well as coupons collected from exposure sites. Rust formed on the bare and scribed coated coupons are investigated. It is found that normal marine environment at Digha exhibits higher corrosion rate than polluted marine environment in Channai. Rust analysis indicates formation of ${\propto}$-FeoOH protects or reduces corrosion rate at Channai and formation of non-protective ${\gamma}$-FeoOH increases corrosion rate at Digha. The slower corrosion rate in Channai than at Digha is attributed due to availability of $SO_2$, in the environment, which converts non‐protective rust ${\gamma}$-FeoOH to protective rust ${\propto}$-FeoOH. While comparing the damage on the coated panels it is found that low alloy structural steel provides less damage than plain carbon steel. From the experimentations a suitable paint system specification is drawn for identical environments for low medium and high durability.