• Journal of Conservation Science
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• v.29 no.2
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• pp.139-147
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• 2013

This study focused on iron making related information through analyzing slags and furnace wall collected from iron production site of Suryong-ri Wonmorongi, Chungju. Total Fe content of slags were from 36.98% to 44.47% and this range was general recovery rate of iron in ancient. Compounds of calcium included slags was supposed to add intentionally during smelting process as deoxidation agent in order that these helped to separate iron from impurities. Furnace wall didn't make of high alumina clay because of low $Al_2O_3$. Microstructure and main components of slags show that No. 1 to 3 slags with fayalite and wustite were products of iron ore smelting. However, No.4 slag is more likely to smelt by iron sand because of ulvospinel with $TiO_2$ in No. 4 slag. Therefore, iron ore were not only used but iron sand in smelting and furnace wall made of general clay with low $Al_2O_3$ content in this area.

• Conservation Science in Museum
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• v.25
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• pp.63-84
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• 2021

In order to investigate the diverse physicochemical changes that occurred in traditional Korean pottery during its production, including before and after firing, this study produced six replicas of a celadon maebyeong inlaid with cloud-and-crane designs, respectively corresponding to the process of shaping, carving, inlaying designs, first firing, glazing and second firing, respectively. It then conducted a scientific study of these six replicas and analyzed their images through high-resolution three-dimensional transmission imaging. The materials used for the replicas show different mineral phases and even colors depending on the components of each material. For example, black inlay with a high content of iron oxide (Fe₂O₃) shows dark colors and white inlay with a high alumina (Al₂O₃) content appears white. Physicochemical properties such as chromaticity and magnetic susceptibility and major components of the replicas were confirmed by the differences in the density in the computed tomography (CT) images. The characteristics of fired products such as fine structure, absorption ratio, apparent porosity, and other characteristics of the major mineral components were identified by the presence of pores and the formation of cracks inside the replicas in the image analysis.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.566-574
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• 2014

This study was conducted to compare the physicochemical composition and fermentation conditions of sliced, dried radish kimchi with flying fish roe (DFFR). The levels of crude protein, crude lipid, and crude ash in DFFR were higher than those in sliced, dried radish kimchi without flying fish roe (control). DFFR also contained higher levels of Fe and Ca, compared to the control. The inosine monophosphate (IMP) content of DFFR and control was 5.63 and 2.64 mg/100 g, respectively. The polyunsaturated fatty acid and DHA contents in DFFR were approximately 5 and 23 times higher than those in the control, respectively. The major free amino acids contained in these samples were arginine, proline, alanine, leucine, and valine. The number of cells belonging to the Leuconostoc species in DFFR was higher than that in the control. In sensory evaluation studies, DFFR scored the highest in terms of appearance, flavor, taste, and texture.

• Journal of the Mineralogical Society of Korea
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• v.21 no.2
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• pp.129-138
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• 2008

The characteristics of beneficiating kaolin mineral by liberation (selective grinding) and air classification have been investigated, comparing the grinding rates of ball mill and impact mill. The ore was ground using a ball mill and a impact mill to evaluate the grindability of the two grinding methods based on the constant production amount of fine particles in size less than 325 mesh. Then, the fine product was further separated into two fractions using an air-classifier and each fraction was chemically analyzed to compare the beneficiation efficiency of the two grinding methods. The chemical grade of kaolin mineral decreased as increasing the grinding rate of both the mills. particularly in the case of ball mill because of overgrinding impurities such as quartz and feldspar. In the case of the ball milling, the fine fraction less than 325 mesh was air-classified at a cutting point of $43\;{\mu}m$. The production rate of the air-classified concentrate was found to be 66.2 wt%, removing 5.3% of $Fe_2O_3$ and 34.6% of CaO. Under the same conditions mentioned above with the impact mill, the production rate of the air-classified concentrate was 64.4 wt%, removing 34.2% of $Fe_2O_3$, 67.6% of CaO and 25.0% of $TiO_2$. Therefore, our results indicate that impact mill is superior to ball mill in terms of impurity removal.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.236-242
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• 1996

This study was conducted to investigate the changes of heavy metals in percolated water of paddy soil in which rice was cultivated in conditions of 0%, 5%. 30% addition of bituminous and anthracite fly ash respectively. In cultivated plot, the contents of Fe in percolated water increased gradually during the cultivation. But there was no sharp difference of Fe contents in fly ash treated plots. The contents of Mn in percolated water increased gradually during the cultivation and was high in the cultivated plot. But difference in the contents of Mn among plots not clear. The contents of Zn in percolated water was highest during 20-25 days in the cultivation, thereafter decreased gradually. The fly ash did not cause to increase the contents of Zn in percolated water. The contents of Cu in percolated water decreased through the cultivation. Fly ash treatment did not cause to increase the contents of Cu in percolated water. The contents of Pb in percolated water decreased gradually over the cultivation. Fly ash treatment did not largely influence to Pb percolation. In mid-July. Pb did not almost appeared in percolated water. The contents of Cd was highest about 15 days of the transplant, thereafter decreased gradually. After 40 day of the cultivation, leach of Cd stopped. When fly ashes were applied in paddy soil, the contents of heavy metals in percolated water was not so much compared with control plot. It seems that originally low contents of heavy metals in fly ash and decrease in solubility of heavy metals in a relatively high soil pH make it possible to use fly ash as a soil conditioner.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.164-169
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• 1998

In order to evaluate the utility of the bituminous coal fly ash, gypsum, oyster shell as soil amendments, acid sandy loam soil with low boron content were amended in the upper 15cm with amendments, and then chinese cabbage was cultivated in fall. Amendments treated were, in metric tons per hectare, i ) none(Check) ; ii) 80 fly ash(FA) ; iii) 4shell(SH) ; iv) 56 fly ash+24gypsum (FG) ; v) 40 fiy ash + 24 gypsum +0.8 shell(FGS). On the whole, amendments imoroved soil chemical properties and contents of N, P, K, Ca, and B in leaves. Among treatmens, FA prominently neutralized soil pH and increased available $P_2O_5$ ,B but decreased Fe contents in soils. FGS also affected the increment of exchangeable Ca, Mg, and available B. Yield response in fresh weight of chinese cabbage was in order of 85% for FGS>77% for FG>66% FA>5% for SH plants. Reducing sugar and vitamin-C contents of leaves depending on treatments showed the same tendencies as that in yields, whereas crude fiber opposite to theme. In particular, FA, FG, and FGS plants showed normal growth without boron deficiency symotoms which appeared in Check and SH plants.Taken together, FGS was an effective combination enable to maximize the utility of fly ash, gypsum, and shell as soil amemdments, especially in cabbage yield and quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1195-1204
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• 2017

This study was designed to determine the effects of three cooking methods, boiling, microwave, and steaming, on elemental compositions of green pumpkin, zucchini, and sweet and ripened pumpkin. The cooking methods were carried out at 3, 5, and 10 min. The samples were then dried, crushed, and decomposed by microwave-assisted digestion method. Macro elements were analyzed by Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES), whereas ICP-Mass Spectrometer (ICP-MS) was used for micro elements determination. From the results, macro elements were present in the order of K, P, Ca, Mg, S, Fe, Zn, and Na in all analyzed pumpkins. Among micro elements, Mn, Cu, Rb, and Ba, were present at high levels. For the effects of cooking methods, boiling significantly reduced the concentrations of elements. Cooking time affected concentrations of elements in the same manner with large differences between elemental contents in samples cooked for 5 and 10 min. Regarding micro elements contents, both effects were not significant. Similar elemental compositions with different concentration levels in all pumpkin types were observed. Green pumpkin and ripened pumpkin showed high retention rates of inorganic components upon steaming, and zucchini and sweet pumpkin showed high retention rates upon microwave cooking. Conclusively, cooking method and time affect amounts of residual inorganic ingredients in pumpkin.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.209-216
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• 2004

This study was carried out to investigate the effects of addition of mugwort powder 0.7%, 10/0, 2%) on the quality characteristics of emulsion-type sausages. The pH, color, TBARS, textural properties, minerals content and sensory evaluation were evaluated. The pH values of sausage containing mugwort powder were significantly lower as compared to control during 20 days of storage, but there were higher than those of control at 40 days of storage. The $L^*$ and $a^*$ values of sausage containing mugwort powder were significantly lower as compared to control, but the $b^*$ values were significantly higher in the sausage containing mugwort powder. The TBARS values of sausage containing mugwort powder were significantly lower than those of control at 20 and 45 days of storage. The hardness values of sausage containing mugwort powder were significantly lower than those of control. The Na content of sausage containing mugwort powder were significantly lower as compared to control, but Mg, Ca, Mn and Fe contents were significantly higher in the sausage containing 2%l mugwort powder. Sensory panels evaluated that sausage containing mugwort powder had the higher preference scores in mugwort flavor.

• Korean Journal of Medicinal Crop Science
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• v.6 no.1
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• pp.21-27
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• 1998

This experiment was conducted to increase aromatics in roots of Condonopsis lanceolata by applications of organic matters. Fresh root wt. was increased by conifer/moss application to 79.1g per plant. Crude protein content was also higher at rice straw application than native soil application and crude saponin content was increased by conifer/moss application, but contents of crude fat, fiber and ash were not different in all treatments. Although contents of K, Ca, and Mg were increased by rice straw application, Fe, Mn, Zn, Na and Cu were not significantly different in all treatments, The highest free amino acid was arginine, it was increased by the application of fallen leaves and the highest yield (0,008%) of essential oils was obtained by conifer/moss application. As a result, to produce C. lanceolata plant showing higher quality and aromatic essential oils, it was considered that the most effective organic matter showing high yield and higher aromatic constituents was conifer/moss application of over 3M/T per 10a.

• Economic and Environmental Geology
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• v.36 no.1
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• pp.27-38
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• 2003

Arsenic contamination around Au-Ag mining areas occurs mainly from the oxidation of arsenopyrite which is frequently contained in mine tailings. In weathered tailings, oxidation of sulfide minerals typically results in the formation of abundant ferric (oxy)hydroxides or (oxy)hydroxysulfates near the tailings surface, and arsenic may be associated with these secondary precipitates. In this study, solid phases of arsenic in weathered tailings of some Au-Ag mines were investigated through the SEM/EDS and sequential extraction analyses. The stability of As solid phases and the leaching potential were assessed with the variation of pH and Eh conditions. Oxidation of sulfides in the tailings samples was indicated by depletion of S molar concentrations compared to As and heavy metals. Under XRD examinations, jarosite as an Fe-oxyhydroxysulfate was found in the tailings of Deokeum, Dongil and Dadeok, and scorodite as an As-bearing crystalline mineral was identified from Dadeok which has the highest concentration of As (4.36 wt.%). Beudantite-like phases and some Pb-arsenates were also found under SEM/EDS analysis, and most of As phases were associated with Fe-(oxy)hydroxides and (oxy)hydroxysulfates despite a few arsenopyrite from Samgwang and Gubong. Sequential extraction analysis also showed that As was present predominantly as coprecipitated with Fe hydroxides from Dongil, Dadeok and Myungbong (72∼99%), and as sulfides (58%) and Fe hydroxide-associated forms (40%) from Samgwang and Gubong. In the tailings leaching experiment, As was released with high amounts by the dissolution of As-bearing Fe(oxy)hydroxysulfates in the lowest pH (2.7) conditions of Deokeum, and by desorption under alkaline conditions of Samgwang and Gubong. Higher leaching rates of arsenite(+3) were found under acidic conditions, which pose a higher risk to water quality. Changes in pH and Eh conditions coupled with microbial processes could influence the stabilities of the As solid phases, and thus, time amendments or landfilling of weathered tailings may result in enhanced As mobilization.