• Economic and Environmental Geology
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• v.29 no.6
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• pp.689-698
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• 1996

The coal-bearing metapelites from the Hoenam area are interbedded within the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with trace amount of biotite, chlorite, pyrite, rutile and barite. Although the formation was mined for coal, and the contents of V, U and Mo are a higher grade in coal formations than the host metapelites. The ratios of Al/Na and K/Na in coal formation are very heterogeneous and wide range from 10.28 to 90.91 and from 3.73 to 36.60, respectively. The V content increase with increasing Al and Ba contents, but the U and Mo are not related with other elements. Those are suggested that controlled of mineral compositions in coaly metapelites due to substitution, migration and reequilibrium of elements by regional metamorphism. These coal formation were deposited in basin of marine environments and the REE of these rocks are not influenced with metamorphism and hydrothermal alterations on the basis of Al content versus La, La against Ce, the ratios of La/Ce (0.23 to 0.73) and Th/U (0.03 to 16.6). These rocks also show much variation in $La_N/Yb_N$ (0.53 to 14.19), Th/Yb (0.51 to 6.00) and La/Th (0.15 to 18.92), and their origin is explained by derivation from a mixture of sedimentary and metasedimentary rocks. The wide range in trace and REE element characteristics as Co/Th (0.07 to 3.00), La/Sc (0.04 to 23.48), Sc/Th (0.06 to 7.57), V/Ni (2 to 3319), Cr/V (0.03 to 1.06) and Ni/Co (1.00 to 79.85) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.3
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• pp.11-20
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• 1988

A general finite element method is developed to analyze reinforced concrete plates under dead loads and monotonically increasing live loads. This method can be used to trace the load-deformation response and crack propagation through elastic, inelastic and ultimate ranges. The internal concrete and steel stresses can also be determined for any stage of the response history. A layered 8 node isoparametric element taking account of coupling effect between the membrane and the bending action is developed. An incremental tangent stiffness method is used to obtain a numerical solution. Validity of the method is studied by comparing the numerical solutions with other results.

• Transactions of Materials Processing
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• v.9 no.4
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• pp.348-355
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• 2000

The backward tracing scheme(BWT) of the finite element method has been extended lot the design of sheet blank in three-dimensional deformation. Originally the scheme was developed for preform design in bulk forming, and applied to several forming processes successfully. Its key concept is to trace backward from the final desirable configuration to an intermediate preform or initial blocker. A program for initial blank design in sheet forming which contains the capabilities of forward loading simulation by the finite element method and backward tracing simulation, has been developed and proved the effectiveness by applying to a square cup stamping process. In the blank design of square cup stamping, the backward tracing program can produce an optimum blank configuration which forms a sound net-shape cup product without machining after forming. For the confirmation of the analytic result derived from the backward tracing simulations as well as forward loading simulations, a series of experiment were carried out. The experiments include the first trial sheet forming process with a rectangular blank, an improved process with a modified blank preform and the final process with an optimum blank resulted from the backward tracing scheme. The experiments show that the backward tracing scheme has been implemented successfully in blank design of sheet metal forming.

• The Journal of the Petrological Society of Korea
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• v.14 no.3 s.41
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• pp.127-140
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• 2005

The Samyuri area of Jeoksang-myeon, Muju-gun at the Middle Yeongnam Massif consists of granitic gneiss, porphyroblastic gneiss and leucocratic gneiss, which correspond to Precambrian Wonnam Series. Here we discuss a geochemical implication of the data based on major element composition, trace element, rare earth element (REE), Sm-Nd and Rb-Sr isotope systematics of the boring cores in the granite gneiss area. The boring cores are granitic gneiss (including biotite gneiss) and amphibolite. The major and trace element compositions of granitic gneiss and amphibolite suggest that the protolith belongs to TTG (Tonalite-Trondhjemite-Granodiorite) and tholeiitic series, respectively. Chondrte-normalized REE patterns vary in LREE, HREE and Eu anomalies. The granitic gneiss and amphibolite have Sm-Nd whole rock age of $2,026{\pm}230(2{\sigma})$ Ma with an initial Nd isotopic ratio of $0.50979{\pm}0.00028(2{\sigma})$ (initial ${\epsilon}_{Nd}=-4.4$), which suggests that the source material was derived from old crustal material. Particularly, this initial ${\epsilon}$ Nd value belongs to the range of the geochemical evolution of Archean basement in North-China Craton, and also corresponds to the initial Nd isotope evolution line by Lee et al. (2005). In addition, chondrite-normalized REE pattern and initial Nd value of amphibolite are very similar to those of juvenile magma in crustal formation process.

• Journal of the Korean earth science society
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• v.28 no.6
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• pp.733-742
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• 2007

Petrological, mineralogical, and geochemical analyses were carried on the paleolithic obsidian implements excavated at Wolseongdong, Daegu, Korea. The obsidians has a homogeneous glassy texture that can be observed in a typical obsidian formed from a rapid cooling of silicic magma. Major element composition of the obsidians represent calc-alkaline series. Comparing those with other obsidians from domestic local excavation sites, Mt. Baekdu, and Kyusu of Japan, the Wolseongdong obsidians show similar element distribution pattern with others in spite of small difference in trace and rare Earth element contents. Sr isotopes of the obsidians considerably differ from those of the obsidians from southern part of the Korean Peninsula or from Mt. Baekdu. K-Ar age is approximately 30 Ma, which is much older than Mt. Baekdu (10 Ma). Therefore, considering the characteristics of obsidians found in the Korean Peninsula including mineralogy, petrology, trace element, and isotopes chronology, the obsidians can be divided into four groups: Mt. Baekdu, southern part of Korea (Kyusu of Japan), middle part of Korea, and Wolseongdong region. These groups suggest a possibility of more than four different origins of the obsidians found in the Korean Peninsular.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.355-365
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• 2022

Precipitation and phase transition of iron minerals in mine drainage greatly affect the behavior of trace elements. However, the precipitation of ferrihydrite, one of the major iron minerals precipitated in drainage, and the related behavior of trace elements have hardly been studied. In this study, the effects of pH change and time on mineral precipitation characteristics in mine drainage from the Munkyeong coal mine were investigated, and the behavioral changes of trace elements related to the precipitation of these minerals were studied. In the case of precipitated mineral phases, goethite was observed at pH 4, and 2-line ferrihydrite mixed with small amount of 6-line ferrihydrite was mainly identified at pH 6 or higher. In addition, it was observed that the precipitation of calcite additionally increased as the pH increased in the samples at pH 6 or higher. The occurrence of goethite was probably due to the phase change of initially precipitated ferrihydrite within a short time under the influence of low pH. Our results showed that the concentration of trace elements was strongly influenced by pH and time. With increasing time, Fe concentration in the drainage showed a abrupt decrease due to the precipitation of iron minerals, and the concentration of As existing as oxyanions in the drainage, also decreased rapidly like Fe regardless of the pH values. This decrease in As concentration was mainly due to co-precipitation with ferrihydrite, and also partly to surface adsorption on goethite at low pH in drainage. Contrary to this observation, the concentration of other trace elements, such as Cd, Co, Zn, and Ni was greatly affected by the pH regardless of the mineral species. The lower the pH value, the higher the concentration of these trace elements were observed in the drainage, and vice versa at higher pH. These results indicate that the behavior of trace elements present as cations is more greatly affected by the mineral surface charge influenced by the pH values than the type of the precipitated mineral.

• Preventive Nutrition and Food Science
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• v.17 no.4
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• pp.299-305
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• 2012

Yam has been recognized having the beneficial effects for the prevention of various diseases, such as cancer, immunity, infection and obesity etc. There is increasing consideration to supplement the antioxidant nutrients to make up the lack of the antioxidant nutrient intakes. No study has been reported for the analysis of antioxidant mineral contents and comparison to dietary recommended intake for the sense of health promotion. In our study, we analyzed the contents of antioxidant trace elements (Zn, Mn, Fe, Cu and Se) and Cr contents in cultivated Korean yam powders for evaluation of nutrient intake aspects. We collected the commercial yam powders from six different cultivated areas in the South Korea and measured antioxidant minerals (Zn, Mn, Fe, Cu and Se) and Cr contents using trace element-free plasma spectrometer (ICP) or atomic absorption spectrometer (AAS) after dry-ashing and then wet-acid digestion. The accuracy of mineral analysis method was confirmed by the mineral analysis of standard reference material. Each analyzed element contents in yam were compared to dietary reference intakes of Koreans (KDRIs). The average levels of trace elements (Zn, Mn, Fe, Cu, Se and Cr) in yam powders were 18.3, 11.9, 36.0, 3.7, 1.9 and 1.27 ${\mu}g/g$ yam powder, respectively. The intakes of Zn, Fe, Cu and Se of which KDRIs is determined, are accounted as being up to 23.8%, 55.6%, 32.5% and 236% recommended intake (RI) of KDRIs, if daily yam supplementation (50 g) of commercial instruction would be considered. The intake of Mn is about 25% adequate intake (AI) of KDRIs with the daily supplementation of yam powder. Most of mineral intakes from daily yam supplementation were with the range of non-detectable to <10% upper limit (UL) level, which is very much safe. The study results show that daily supplementation of Korean yam power is beneficial to provide the supplemental nutrient intake and also is safe, if the suggested dosage would be considered.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.1
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• pp.49-59
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• 1995

Nine species of edible seaweed [green laver (Monostroma nitidium) and sea staghorn ( Codium fragile) of green algae; sea mustard (Undaria pinnatifida), seaweed fusiforme(Hizikia fusiforme), gulf weed (Sargassum fulvellium), and sea tangle (Laminaria japonica) of brown algae; seaweed dilatata (Halimeniopsis dilatata), seaweed furcata (Gloiopeltis furcata), and laver (Porphyra tenera) of red algae] collected from Kijang, Chungmu, and Yosu in Korea, were examined and compared on their chemical and mineral composition depending on their harvesting season. Crude protein $(N\pm6.25)$ showed about $45\%$ on moisture free basis (the contents of every components described below are shown as moisture free basis) for laver and $30\%$ for green laver collected from ever seasons and sites. Sea tangle showed the highest content in crude lipid $(10\%)$ among brown seaweeds and green laver had $6\%$ of crude lipid regardless their habitats. Ash and carbohydrate in sea staghorn hold about $90\%$ of total solids but those levels were only $50\%$ in laver. The relationship between ash and carbohydrate content showed a tendency with reverse correlation. Mineral compositions were examined on green laver, sea mustard, and seaweed furcata collected from Kijang. Sodium was eminent element (1,798-7,334mg/l00g) followed by potassium. Magnesium and calcium content were low level compared with sodium and potassium. As a micro-element iron was appraised the highest status (165-330mg/100g) in green laver, however, iron in sea mustard and seaweed furcata was comparatively low amount (2.7-47.4mg/100g). The level of zinc was also comparatively high and that was varied on habitats. In conclusion, chemical compositions of these algae were distinctively varied on species and habitats, and mineral compositions were notably changed by the harvesting season.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.287-295
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• 2010

Dust samples have been collected from streets, schools, subway stations and households in Daegu metropolitan city. Samples were sieved through a 100 ${\mu}m$ mesh and the concentration of 14 elements have been determined using by ICP after acid extraction. Results showed that Ca, Fe, K, Mg, Mn, Na and V were influenced by natural sources while Cd, Cr, Cu, Ni, Pb and Zn were influenced by anthropogenic sources. The measured values were remarkably higher in components from natural sources than in components from anthropogenic sources. In particular, school dust had higher levels of Ca and Pb and subway station dust had higher levels of Cu and Zn. The percentage composition of chemicals from subway stations, households, and schools were remarkably higher in components from anthropogenic sources than that from streets. It is well recognized that anthropogenic sources were affected by indoor dust. Results of pollution index of hazardous heavy metals indicated that schools, households, and subway stations were more contaminated than streets and urban areas typically had higher pollution index than rural areas. The correlation analysis among trace elements seem to suggest that there were correlations between components of soil/road dust resuspension, and components of waste incineration and fuel combustion.

• Economic and Environmental Geology
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• v.29 no.4
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• pp.483-493
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• 1996

The tectonic environment and source characteristics of the Daebo granitic batholith in the central Ogcheon Belt were investigated based upon major and trace element geochemistry. The batholith is comprised of three granite types; a biotite granite (DBBG), K-feldspar megacryst-bearing biotite granite (DBKG), and a more mafic granodiorite (DBGD). The variations of Na and K in the granites can not be explained by simple fractional crystallization from the same primary magma. The irregular behavior of these alkali elements indicates a variety of source materials or incomplete mixing of different source materials. The large ion lithophile (LIL) element enrichment and low Ta/Hf ratios of the granites are typical characteristics of normal, calc-alkaline continental arc granitoids. Based upon REE patterns of the granites, it seems to be unreasonable to regard the felsic DBBG as a late stage differentiate formed by residual melts after the fractionation of major constituent minerals of the more mafic DBGD. Inconsistent variations in ${\varepsilon}_{Nd}(t)$ and LIL element concentrations of the granites preclude a mixing model between primitive melt and LIL element-enriched upper crustal materials. The irregular geochemical variation of the granites is taken to be largely inherited from an already heterogeneous source region.