• Journal of the Mineralogical Society of Korea
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• v.28 no.2
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• pp.135-145
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• 2015

In order to predict the deterioration of stone monument due to acid fog, an artificial fog test using pH4.0 and pH5.6 was applied to the Gyeongju Namsan granite, decite and marble. After the test had weathered Gyeongju Namsan granite a larger weight reduction due to acid fog than fresh one. Decite has shown the most significant changes among the tested rocks with about 0.005 % of weight reduction. Decite and weathered granite will have considerable weight reduction due to acid rain than the acid fog, whereas the marble was expected to show a weight reduction regardless of the phase of water. The porosity and water absorption rate of weathered granite had significantly increased. This result means that the weathered rock is predicted to be more susceptible to acid fog than the fresh rock. The absorption rate of the marble after the test had shown approximately 50 % increase. The color of the samples had slightly changed towards yellow, such tendency was greater shown in weathered rocks. The marble reacted with acid fog had an increased whiteness. A large amount of cation in the samples is caused mainly by the dissociation of minerals through the reaction with acid fog.

• Journal of Conservation Science
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• v.28 no.3
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• pp.235-245
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• 2012

Nondestructive deterioration diagnosis has been carried out for the former ore dressing plant of the Yongwha mine in Yeongyang (Registered Cultural Property No. 255). Deterioration rates about organic contaminant and soil of the upper part (7 to 13 layer) indicate higher than the lower part (1 to 6 layer) of the ore dressing plants. By contrast, deterioration rates such as crack, break out and discoloration of the lower part indicate very higher than the upper part. It is estimated that the plants of the lower part that mechanical and chemical process had been done for flotation were damaged severely by physicochemical weathering with reaction of concrete and chemical solution. As results of ultrasonic velocity measurement, average p-wave velocity of plants were measured 2,462m/s (compressive strength $529kgf/cm^2$). As for the analytical results of surface contaminants and soil compositions using P-XRF, they were identical with major elements (Cu, Zn, Pb, Fe and As) of ore minerals from the Yongwha mine. Therefore, the ore dressing plant should be treated by phytoremediation with conservation because heavy metals could impinged upon plants and natural environment.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.4
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• pp.275-286
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• 2014

This study evaluated the evolution stage and origin of chemical components of 12 boreholes at crystalline bedrock using multivariate statistical and groundwater quality analyses. Groundwater types are mostly belonged to Na(Ca)-$HCO_3$ and Ca-$HCO_3$ types, indicating that directly reaction of cation exchange ($Ca^{2+}{\rightarrow}Na^+$) prevailed. The degree of groundwater evolution is included the range from low to intermediate stage based on field and laboratory analytical conditions. As a result of multivariate statistical analysis, a typical indicator of groundwater contamination, $NO_3$-, has the positive correlation with $Na^+$ and $Cl^-$. The origin of sea spary ($Cl^-$) has the positive correlation with $Na^+$, $SO{_4}^{2-}$, $Mg^{2+}$, and $K^+$, while not correlation with $Ca^{2+}$, $Fe^{2+}$, $HCO_3{^-}$, $F^-$, and $SiO_2$. The concentration of $Cl^-$ and $NO_3{^-}$ belongs to general quality of groundwater and not exceeds over the Korean standard for drinking water. And the negative values of saturation index of minerals are calculated with chemical components in groundwater. Therefore, most of chemical components of groundwater in the study area are originated from natural process between rock and groundwater, whereas some of components are derived from sea spary and anthropogenic sources related to agricultural activities.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.778-785
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• 2020

The purpose of this study was to investigate in vitro antibacterial activities of pozzolan against super bacteria and intestinal bacteria. There were four treatment groups: 1) CON, pozzolan free control group; 2) DP0.3, microbial culture medium prepared by mixing distilled water and 0.3% of pozzolan powder; 3) DP0.5, microbial culture medium prepared by mixing distilled water and 0.5% of pozzolan powder; and 4) PE, microbial culture medium prepared with pozzolan powder extracts without adding distilled water. The count of Lacctobacillus casei was significantly higher in the DP0.3 group compared to CON (P<0.05). However, it showed no significant difference compared to other treatment groups. Numbers of Clostridium butyricum, Escherichia coli, and Salmonella typhimurium were significantly lower in pozzolanic treatment groups compared to CON (P<0.05). Clostridium butyricum and Salmonella typhimurium counts were significantly different among DP0.3, DP0.5, and PE groups (P<0.05). Counts of E. coli were also significantly between DP0.5 and PE groups (P<0.05). Counts of MRSA and VRE were significantly lower in pozzolanic treatment groups compared to CON (P<0.05). MRSA counts were significantly different among DP0.5, DP0.3 and PE groups. VRE counts were significantly higher in the order of PE > DP0.3> DP0.5> CON (P<0.05). These results suggest that pozzolan could be used as a dietary silicate supplement and a natural antibacterial agent for livestock if its antimicrobial activity against super bacteria and harmful bacteria in the intestine is confirmed.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.6
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• pp.657-662
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• 2005

Iron sulfide(FeS) is significantly produced through both abiotic and biotic processes in natural sediments and pore waters. In this study, chromium(VI) reaction with iron sulfide at various initial concentrations and at pH values of 4 and 8 was conducted to better understand the interactions between Cr(VI) and Fe(II) species dissolved from iron sulfide in both the aqueous and solid phases. Also, the removal efficiency of iron sulfide was compared with zero valent iron and other iron bearing oxides such as ${\alpha}-Fe_2O_3$, ${\alpha}-FeOOH$ and $Fe_3O_4$. The Cr(VI) removal rate by iron sulfide was higher at pH 4 than at pH 8 because more dissolved Fe(II) existed at pH 4 than at pH 8. Chromium and iron(oxyhydroxide) could be identified on the iron sulfide surface with transmission microscopy imaging and energy dispersive spectroscopy. The removal capacity of iron sulfide was much higher than zero valent iron and other iron oxide minerals due to the synergic effect of hydrogen sulfide and ferrous iron.

• Journal of Nutrition and Health
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• v.45 no.2
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• pp.192-200
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• 2012

Fruits are generally recommended for a balanced meal, as they are good sources of vitamins, minerals, and fiber, which may improve blood glucose control. However, fruits have simple sugars with a wide glycemic index (GI) range. The purpose of this study was to analyze the sugar content and composition and to determine the glycemic indices of the most frequently consumed fruits in Korea, including apple, tangerine, pear, water melon, persimmon, grape, oriental melon, and peach. The sugar content and composition of the fruits were analyzed by high performance anion-exchange chromatography (Dinonex model DX-600). The GI of the fruits was measured in 13 healthy subjects (seven females and six males) after permission was received from the University Hospital institutional review board (KHU-IRB 1114-06). The subjects consumed 50 g of glucose as a reference and carbohydrate portions of eight fruits. Blood samples were collected at 0, 30, 60, 90, and 120 min after consuming the fruits. The GI values for the fruits were calculated by expressing the increase in the area under the blood glucose response curve for each subject. As a result, the total sugar contents of 100 g fruits were: grape (13.9 g), apple (12.3 g), persimmon (11.9 g), oriental melon (11.2 g), watermelon (9.3 g), tangerine (8.9 g), peach (8.6 g), and pear (8.3 g). The GI values of the fruits were as follows: GI value of peach ($56.5{\pm}14.17$), watermelon ($53.5{\pm}18.07$), oriental melon ($51.2{\pm}18.14$), tangerine ($50.4{\pm}15.16$), grape ($48.1{\pm}14.05$), persimmon ($42.9{\pm}18.92$), pear ($35.7{\pm}14.38$), and apple ($33.5{\pm}11.92$). These findings will help individuals choose fruit for controlling blood sugar.

• Journal of the Mineralogical Society of Korea
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• v.24 no.1
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• pp.37-42
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• 2011

Magnetic properties at low-temperatures can diagnose the presence of certain magnetic minerals in rocks. At the Verwey transition temperature ($T_v$, ~105~120 K), magnetite transforms from monoclinic to cubic structure as the temperature increases. At the isotropic point ($T_i$, ~135 K), magnetocrystalline anisotropic constant of magnetite passes through zero (from negative to positive) as the temperature decreases so that its optimal remanence acquisition axis changes from [111] to [001]. A sharp remanence drop was observed at $T_v$ during warming of LTSIRM (low-temperature saturation isothermal remanent magnetization). For cooling of RTSIRM (room-temperature saturation isothermal remanent magnetization), the remanence decreased on passing $T_i$ and $T_v$. On warming of RTSIRM, remanence recovery becomes more prominent as the average grain size of magnetite increases. In summary, the SIRM memory decreases with increasing grain size of magnetite. A similar, but rather gradual, remanence transition occurs for natural samples due to contribution of cations other than Fe. As a non-destructive tool, low-temperature magnetic behavior is sensitive to unravel the magnetic remanence carriers in terrestrial rocks or meteorites.

• Journal of the Mineralogical Society of Korea
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• v.22 no.1
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• pp.35-47
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• 2009

The deteriorations of stone monuments located in Gyeongju area are predicted in a modeling study. Artificial rain and accelerated weathering test are here applied to the Gyeongju Namsan granite and cement mortar. They are reacted with pH 4.0, pH 8.0 and pH 5.6 rain, respectively. The two former values are the limited acidity values in the Gyeongju (the acidity of rain of the Gyeongju were pH $4.93{\sim}6.39$ in 2005) and the latter is the limited acidity of acid rain. The rains of pH 5.6 and pH 8.0 reach close to a value of pH 7.0 after the reaction with the Gyeongju Namsan granite. After application of the artificial rain and weathering test, the weight of specimens were reduced and the contents of soluble ions in the specimens were increased. These results are attributable to solution of minerals in the specimens. At first, the microlithic have dissolved in ground from the reaction with acid rain. And then mainly quartz, plagioclase and orthoclase bound by the microlithic are disintegrated. The cement mortars are dissolved after the reaction with not only acid but alkali rain. The concentrations of ions in the dissolved cement mortar are higher than those in granite.

• Journal of Environmental Science International
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• v.21 no.2
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• pp.181-188
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• 2012

Salicornia europaea (glasswort) is succulent, annual, halophytic plant mainly distributed throughout reclaimed land or salt marsh. It has strong tolerance to salt so that it plays the part of the pioneer species in the first succession. According to domestic and foreign studies, S. europaea contains plenty of minerals and antioxidant in the body. Since people take note of an availableness of this plant as health diet, the natural growth sites are threatened. In addition to development of salt marsh and sea shore, imprudent harvest has a bad effect to S. europaea population maintenance. To seek ways to preserve the population of this plant, we carried out the continuity of seed germination and restoration test. Seokmo Island, Daebu Island, Youngjong Island and Sudokwon landfill in Korea are selected sites for research. Result of germination continuity shows that most S. europaea seeds germinate on March but no more after July. However the germination was occurred after that time in the greenhouse. So we concluded that no germination after July is a matter of environmental condition not the number of remaining seeds. Also germination was seldom occurred in the spot where seeds production was not happened. In result of continuity test of seed germination by soil depth, germination was occurred vigorously only in top soil. From these results, we note that most S. europaea germinate in the early spring, and germination is finished by July. And this rapid germination speed makes the number of seeds in soil seed bank rare. If a large number of S. europaea in some area are harvested after July, the number of this species will dramatically decrease in that area the following year. In Seokmo Island, we carried out reintroduction experiment by sowing S. europaea seeds. On the first year, a small number of S. europaea settled and they produced seeds successfully. On April 2010, the second year, we observed many S. europaea in seed sowing sites. And we found out that plowing is more efficient than treatment sea water for settlement of S. europaea.

• Journal of environmental and Sanitary engineering
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• v.19 no.2
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• pp.15-22
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• 2004

Yellow loess, Tidal plat sediment, and mud are blown to be high in adsorption though they have great distinction according to the ratio of clay minerals content and their kinds. Thus one of the samples for this study can be obtained by drying of Yellow loess, Tidal plat sediment, and the mud which is semifinished products that are from the progress of heat treatment and making homogeneity which can be found everywhere in our county. Another sample can be prepared by reducing pollutants with the adsorbent and by homing heavy metals of their on. With the samples, noxious heavy metals such as Pb, Cd, and essential trace elements such as Cu, Fe, Mn by each concentration is tested for adsorption according to pH, the kinds of adsorbents and the amount of injection. With the help of these steps, this study shows that the adsorbents, which are green, reducing the additional pollution and low in price, can be found. It also shows that the optimal condition for removing pollutants can be found and the basic materials for treating water can be offered. The results were as follows ; Yellow loess shows the rates of adsorption by more than 50% and Tidal plat sediment and Mud show it by more than 90%. Thus Tidal plat sediment and Mud are higher than Yellow loess the rates of adsorption. The pH should be treated in natural condition because the rates of adsorption of Pb, Cd, Cu, Mn excepting Fe in mud is higher in pH 7 than in pH 3 of Yellow loess, Tidal plat sediment, and Mud. The drying adsorbents are good to use because the rates of adsorption of heavy metals has tendency to be higher in the drying method than in the burning method. It is considered that the more the mont of the injection of the adsorbent is , the higher the rates of adsorption is, and one gram is reasonable for the amount of the injection of Tidal plat sediment and mud. Yellow loess is suitable for the treatment of the water that includes low concentration of heavy metals because it has the lower rate of adsorption as the concentration of noxious heavy metals is higher. It is thought that Tidal plat sediment and Mud is proper for the treatment of the water that includes high concentration of heavy metals because the rates of adsorption has not been changed as the concentration of heavy metals increases.