• Economic and Environmental Geology
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• v.11 no.3
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• pp.89-98
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• 1978

Mineralogy, beneficiation, and processes of titanium ores are reviewed from petrographic viewpoints. The most important titanium minerals are ilmenite ($FeTiO_3$) and rutile ($TiO_2$). Ilmenite will play major role :for raw material, because rutile are rapidly diminishing. Thus, there is a need to develope a successful process for producing high grade Ti02 from ilmenite. Commercial, as well as R and D processes to treat more abundant ilmenite ores fall in three general classess: 1. Iron in ilmenite is partially or completely reduced and separated either physically or chemically. 2. Iron is reduced to ferrous state and chemically leached away from the titanium. 3. Ore is treated to make chlorides either selectively or with subsequent separation and purification of $TiC_4$. Routes and efficiencies of these process technologies are primarily influenced by the particular ore deposit to be mined and secondly by environmental considerations. One deposit parameters which influence ilmenite process technologies are: 1. Complexity of microtextures of ilmenite intergrown with Fe-oxide minerals. 2. Composition of concentrates; ilmenites contain minor amounts of substituted Mg, Mn, and V. These elements plus iron and gangue minerals can cause difficulties to complete reactions, substantial acid consumption, difficulties of removing waste solids, and waste disposal problems. Major contributions to be made by petrologists for process optimization are: characterization and interpretation of compositional and physical changes of raw materials and solids derived from process streams. These informations can play significant role in selecting and improving process steps for titania production.

• Economic and Environmental Geology
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• v.26 no.2
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• pp.117-127
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• 1993

Ag-Au vein ores from the Weolyu mine, Youngdong district, contain significant germanium (up to 145g/t, average 34.9g/t), in the form of argyrodite ($Ag_8GeS_6$). Mineral chemistries of argyrodite and its associated minerals were determined by electron probe microanalysis. Twenty eight elements in thirteen ore samples were analyzed using an ICP mass spectrometer. Argyrodite occurs in the paragenetically later mineral assemblage consisting of carbonates+quartz+native silver+argentite+Ag-sulfosalts, indicating that the germanium mineralization represents the culmination of a complex mineral sequence which includes early gold and late silver deposition. The mean formula of the argyrodite is $Ag_{7.90}\;(Ge_{0.76}Sn_{0.04})S_6$, with minor amounts of Cu, Fe, Sb, As, Sn, and Zn. The Weolyu argyrodite shows systematic substitutions of Ag by Cu, and of Ge by Sb. Chemical analyses of vein ores indicate that metals were precipitated in the order of $Fe{\rightarrow}Pb$, $Zn{\rightarrow}Cu{\rightarrow}Ag$, Sb, As, Ge. Germanium has a strong geochemical affmity with As and Sb, and Cu, Pb, Zn, Mo, and Sr show weak positive correlations with Ge. Germanium deposition at Weolyu was mainly a result of cooling of hydrothermal fluids (down to $175^{\circ}C{\sim}210^{\circ}C$, due to increasing involvement of cooler meteoric waters in the epithermal system.

• The Journal of Engineering Geology
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• v.9 no.3
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• pp.207-225
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• 1999

Twenty water samples (eleven groundwater and nine geothermal water samples) were collected to elucidate hydrogeochemical characteristics of the groundwater and geothermal water in the Dongrae hot-spring area and its vicinity. Major and minor elements were analyzed for ground and geothermal water samples. Physicochemical properties of the groundwater and the geothermal water were examined and chemical composition of the two waters were compared. Factor and correlation analyses were carried out to simplify the physicochemical data into grouping some factors and to find interaction between them. The groundwaters belong to $Ca-HCO_3$ type, while the geothermal waters belong to Na-Cl type. The Na and Cl concentrations in the Dongrae hot-spring area are higher than those of other granite areas in South Korea. The Na/Cl weight ratio ranges from 0.7 to 1.3 for the geothermal waters. On the phase stability diagram groundwaters fall effectively in the field of stability of kaolinite, while geothermal waters fall in the stability field of microcline or kolinite depending on the chemical composition system. Based on the Na-K, Na-K-Ca and Na-K-Ca-Mg geothermometers, the geothermal reservoir is estimated to have equilibrium temperature between 115 and $145^{\circ}C$.

• Journal of Conservation Science
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• v.31 no.2
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• pp.159-173
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• 2015

The patternless potteries excavated from the Baekseokdong Gojaemigol site in Cheonan, was subdivided into talc and non-talc (including amphibole) type pottery. The potteries showed black, reddish brown and yellowish brown colors, but represent to difference with occurrences and internal texture of raw materials and temper minerals. The all potteries and paleosoils are commonly high content of temper minerals with poorly sorting and roundness of particles, and the paleosoils composed mainly of quartz, plagioclase, mica, chlorite and kaolinite. Between the talc and non-talc type potteries are very similar with magnetic susceptibility, absorption ratio and specific gravity. Geochemical behaviors of major, minor, compatible and incompatible elements in talc pottery are very similar with amphibole, non-talc pottery and paleosoils, and well correspondence with enrichment and deficiency patterns of each element, and the talc and amphibole potteries are highly enriched patterns of MgO concentration. In paleosoils of Gojaemigol site, talc and amphibole are not detected, therefore, making the pottery of the site estimate the possible to artificial additions of the temper minerals of talc and amphibole used interbedded talc layer within gneiss complex near the Baekseokdong area. Based on the phase relations, differential thermal and thermal gravimetric analyses, the potteries could be classified into two groups by firing temperature. The one group of talc temper pottery fired from 800 to $870^{\circ}C$ and the other group of amphibole and non-talc temper pottery revealed of 900 to $950^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.1038-1044
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• 2006

The effects of the addition of soybeans cultured by mycelia of Pleurotus eryngii (SMP) on the characteristics of tofu were studied. Protein and ash contents of SMP were higher than those of untreated soybeans: 43.23 and 6.34% for treated soybeans, respectively, and 40.42 and 5.90% for untreated soybeans. But lipid and carbohydrate contents of SMP were lower. For minor elements, Mg and Ca contents of SMP were higher and P was lower than control. Tofu could be manufactured when SMP was added below 25% to the untreated soybean. In scanning electron microscopic observation, tofu tended to break down as the ratio of SMP was over 25% to the untreated soybean. The addition of SMP $(5{\sim}15%)$ increased the yield of tofu to $1.5{\sim}3.5%$. In textural characteristics, hardness of tofu increased as the ratio of SMP increased up to 20%. Cohesiveness, chewiness, springiness and gumminess were high in tofu which was made with $5{\sim}15%$ SMP. Savory taste and overall acceptability of the tofu prepared with $5{\sim}15%$ SMP were higher than those of control when evaluated by sensory test.

• Spatial Information Research
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• v.22 no.6
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• pp.55-65
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• 2014

By combining the role of current GIS technology and design behaviors from the cognitive perspective, spatial conceptualization can be extended efficiently and creatively for ill-structured problems. This study elaborates the model of a conceptualization-oriented SDSS(Spatial Decision Support System) for a landscape design problem. Current information-oriented GIS technology plays a minor role in planning and design. The three attributes in planning and design problems describe how the deficiencies of current GIS technology can be seen as a failure of the technology. These are summarized: (1) Information Explosion/Information Ignorance (2) Dilemma of Rigor and Relevance (3) Ill-structured Nature of planning and Design. In order to implement the conceptualization idea in the current GIS environment, it will be necessary to shift from traditional, information-oriented GISs to conceptualization-oriented SDSSs. The conceptualization-oriented SDSS model reflects the key elements of six important theories and techniques. The six useful theories and techniques are as follows; (1) Human Information Processing (2) Tool/Theory Interaction (3) The Sciences of the Artificial and Epistemology of Practice (4) Decision Support Systems (DSSs) (5) Human-Computer Interaction (HCI) (6) Creative Thinking. The future conceptualization-oriented SDSS can provide capabilities for planners and designers to figure out some "hidden organizations" in spatial planning and design, and develop new ideas through its conceptualization capability. The facilitation of conceptualization has been demonstrated by presenting three key ideas for the framework of the SDSS model: (1) bubble-oriented design support system (2) prototypes as an extension of semantic memory, and (3) scripts as an extension of episodic memory in a cognitive pschology perspective. The three ideas can provide a direction for the future GIS technology in planning and design.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.3 s.55
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• pp.23-31
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• 2007

Fast bridge construction has been increasingly needed according to the changed construction environment. This paper deals with quasi-static tests on precast piers for bridge substructures. One of the most crucial aspect of the design of precast prestressed concrete bridge piers is the seismic performance. Seven precast pier elements were fabricated. The amount of prestressing bars, the prestressing force, and the location and number of the joint between segments were the main test parameters. Test results showed that the introduced axial prestress made the restoration of the deformation under small lateral displacement and minor damage. However, there was no effect of the prestress when the plastic hinge region was damaged severely due to large lateral displacement. Judging from the observed damage, the design of the joints in precast piers should be done for the first joint between the foundation and the pier segment. The amount of the necessary prestressing steel may be designed to satisfy the P-M diagram according to the service loads, not by having the same steel ratio as normal RC bridge piers. In order to satisfy the current required displacement ductility, it is necessary to have the same amount of the transverse reinforcements as RC piers. As the steel ratio increases, the energy absorption capacity increases. The number of joints showed a little influence on the energy absorption capacity.

• Journal of the Mineralogical Society of Korea
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• v.23 no.4
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• pp.357-365
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• 2010

Optically stimulated luminescence (OSL) of quartz is commonly applied to the age dating of Quaternary sediments. However, one of the issues is that some of the quartz samples are not suitable to OSL dating. Mineralogical analysis of the quartz samples with diverse OSL signals are required to strengthen the reliability and applicability of the OSL dating. We analysed the OSL signal characteristics of sedimentary quartz samples from diverse geological environments and measured their trace element contents using laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Quartz samples could be grouped into ones suitable to OSL dating and ones unsuitable on the basis of their OSL signal characteristics. The average trace element contents ranged from 73 to 260 ppm (Al), and from 61 to 248 ppm (Ti) with minor Li, Mg, Cr, Mn, and Fe contents below 40 ppm. We did not find any significant variation of trace element contents of quartz samples consistent with their OSL signal characteristics. This indicates unknown mineralogical factors causing diverse OSL characteristics which should be confirmed by further analysis of sufficient set of samples.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.1
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• pp.9-14
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• 2008

In the case of horizontally curved bridges, the use of curved composite box girder bridges are increased due to its functionality and for aesthetical reason. As it compared with the open section, the steel box girder bridges have advantages to resistant of distortion and corrosion. In practice the grid analysis is conducted by utilizing only the cross beam. Since the stiffness of the concrete slab is not included in the grid analysis, the cross beam is induced the distribution of the live load. In this study the affects of the radius of curvature, the number of diaphragm and cross beam to the load distribution of the curved steel box girder bridge was investigated by applying the finite element method. The results indicate that the curvature of curved bridge had a large affect of the load distribution and as the curvature was increased the load distribution factor was increased. A single diaphragm at the center of girder is important role for the load distribution effects and structural stability, but additional diaphragm did not affect it as much. The affects of the cross beam to the load distribution were investigated and its influence was minor. It can be safely concluded that the addition of cross beam does not aid the purpose of the live load distribution. And the stiffness of concrete slab for the load distribution effects should be concerned in the design of curved steel box girder bridges.

• Economic and Environmental Geology
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• v.31 no.3
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• pp.249-264
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• 1998

The Creataceous volcanic rocks distributed in the southeastern part (Kyeongsang basin) of Korea peninsula are composed of basalt, basaltic andesite, andesite, dacite and rhyolite. The variation of major elements show that contents of MgO, CaO, $FeO^T$, $Al_2O_3$, $TiO_2$ and $P_2O_5$ decrease with increasing of $SiO_2$, but $K_2O$ contents are increased slightly, $Na_2O$ widely dispersed. We can show slightly inflection point and low frequency of dacites in range between 63-65 wt.% $SiO_2$, while continuous trend exit in variation diagram. Variation trends in Harker diagrams for the major, minor, trace and REEs suggest that the BAV (basaltic to andesitic volcanics) and DRV (dacitic to rhyolitic volcanics) are not related to a simple crystal fractionation process. In the regime of under 65 wt. % in silica content, fractionation of olivine and clinopyroxene is predominant, while that of plagioclase happens strongly higher than 65 wt.% (e.g., $SiO_2$, vs. Eu and Sr, MgO vs. $Al_2O_3$ and CaO). The latter means low-pressure fractional crystallization for DRV. On the discriminant diagram, DRV are located in more mature environment than BAV. The $(Ce/Sm)_N$ vs. CeN digram shows that these two classes cannot be related to crystal fractionation. If they had been produced by fractionation, although they plotted in a slightly elongate cluster along the same horizontal trend, DRV should lie to the right of these primitive compositions. These diagrams clearly rule out a simple fractionation throughout from BAV to DRV. BAV had been influenced greatly subductiong slab as shown by K/Yb vs. Ta/Yb. We suggest that BAV primitive magma generated higher degree of partial melting than DRV primitive magma. LILE (K, Ba, $Rb{\pm}Th$) enriched characteristics as shown in BAV are inherited from subducting slab fluids and/or higher degree of partial melting of mantle material. However, lower degree of partial melting of mantle relative to BA V and contamination at high-level magma reservoir caused LILE enrichment to DRV.