• Proceedings of the Korean Magnestics Society Conference
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• 2012.05a
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• pp.120-120
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• 2012

• Economic and Environmental Geology
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• v.30 no.1
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• pp.35-49
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• 1997

The coal formation of the Deokpyeong area are interbedded along metapelites of the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with small amounts of biotite, chlorite, pyrite and barite. The ratios of $SiO_2/Al_2O_3$, $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ of the coaly metapelite are variable and wide range from 1.80 to 10.21, from 27.8 to 388.8 and from 7.6 to 61.8, respectively. 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 $Al_2O_3$ versus La, La against Ce, the ratios of La/Ce (0.19 to 0.99) and Th/U (0.02 to 4.75). These rocks also show much variation in $La_N/Yb_N$ (1.19 to 22.89), Th/Yb (0.14 to 21.43) and La/Th (0.44 to 13.67), and their origin is explained by derivation from a mixture of sedimentary and igneous rocks. The wide range in trace and REE element characteristics as Co/Th (0.12 to 2.78), La/Sc (0.33 to 10.18), Sc/Th (0.57 to 5.73), V/Ni (8 to 2347), Cr/V (0.02 to 0.67) and Ni/Co (1.56 to 32.95) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation. Deep to pale green barium-vanadium muscovites (vanadium-oellacherite) have been found in this coal formations. Modes of occurrence and grain size of muscovite are heterogeneous, but most of the barium and vanadium-bearing muscovites occur along the boundaries between graphite and quartz grains, ranging from 200 to $350{\mu}m$ in length and from 40 to $60{\mu}m$ in width. Results of X-ray diffraction data of the minerals characterized to be monoclinic system with $a=5.249{\AA}$, $b=8.939{\AA}$, $c=20.924{\AA}$ and ${\beta}=95.894^{\circ}$. Representative chemical formula of the muscovite was $(Na_{0.09}K_{1.44}Ba_{0.46})(Al_{2.75}Ti_{0.07}V_{0.56}Fe_{0.08}Mg_{0.50})(Si_{6.12}Al_{1.88})O_{22}$. The V possibly substitute octahedral Al, and the Ba is coupled substitution of $K^+Si^{4+}=Ba^{2+}Na^+Ca^{2+}$, which compositional ranges of V and Ba are from 0.42 to 0.69 and from 0.34 to 0.56 based on $O_{22}$, respectively. Formation mechanism of the barium-vanadium muscovites in the coaly metapelite is shown that the formed by high pressure and temperature from regional metamorphism origanated during diagenesis at the interface between a basinal brine and organic matter.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.46-54
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• 2002

A dielectric pellets bedded parallel plates with a membrane centered have been proposed as an ion separation and collection system in water. and effects of the relative dielectric constant and the applied square wave pulse voltage on the characteristics of ion separation and collection in tap water and NaCl dissolved tap water have been investigated. As a result, electrolyzed water of pH 3.1 and 10.6 were obtained with only tap water at the pulse current of 1.0[A] and flow rate of 0.5[LPM]. And the higher ionized water of pH 2.8 and pH 11.7 ware obtained in 0.1[%wt] NaCl dissolved water. When the dielectric pellets of BaTiO$_3$ having the highest dielectric constant were bedded in the ion separation and collection cell, the ionized water of pH 2.7 and pH 11.7 were obtained with only tap water. And the ionized water of pH 2.4 and pH 12.0 were obtained in 0.1[wt%] NaCl dissolved tap water with the dielectrics pellets bedded ones.

• Resources Recycling
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• v.14 no.5 s.67
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• pp.32-39
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• 2005

Leaching behavior of nickel contained in waste Multi-Layer Ceramic Capacitor (MLCC) was investigated using a batch reactor. The effects of acid type, acid concentration, leaching temperature, particle size, and reaction time on the extraction of nickel metal from waste MLCC were examined. As a result, 97% of nickel contained in waste MLCC was leached out in 30 min at the temperature of $90^{\circ}C$ under the condition of $HNO_3$ concentration 1N, solid/liquid ratio 5 g/L and particle size $-300/+180{\mu}m$. It was also found that a Jander equation was useful to fit well the leaching rate data. The rate of nickel leaching is controlled by pore diffusion in $BaTiO_3$ layer and has an activation energy of 37.6 kJ/mol (9.0 kcal/mol).

• Economic and Environmental Geology
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• v.42 no.3
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• pp.247-259
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• 2009

This study is focused on the relationship between whole rock boron contents and metamorphic P-T conditions of metasedimentary rocks from northeastern Yeongnam massif around Samcheok area, Korea. Metamorphic P-T conditions of sillimanite and garnet zones based on the Ti-biotite geothermometer is 553-687$^{\circ}C$ and 582-722$^{\circ}C$ at 4-6 kbar, respectively. In the metasedimentary rocks, boron contents in whole rock decrease with increasing metamorphic grade, from sillimanite zone (9.60-189 ppm B) to garnet zone (2.63-15.97 ppm B), except one sample (90.9 ppm B) from garnet zone containing graphites. Boron depletion in garnet zone has relation with mode of tourmaline which are broken down with increasing metamorphic temperature. Boron contents are indirectly proportional to major and trace elements such as $Al_2O_3$, MgO, $Fe_2O_3$, $K_2O$, Li, Ba, Sc, Co, Cr, Rb and Cs that are abundant in tourmalines. In conclustion, tourmalines and graphite are modulator of boron contents in metasedimentary rocks. In the biotite granitic gneisses, boron contents (2.62-12.2 ppm B) are similar or lower than those of metasedimentary rocks and have no relation with metamorphic P-T conditions.

• The Journal of the Petrological Society of Korea
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• v.5 no.2
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• pp.142-160
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• 1996

Petrological and geochemical characteristics of A-type granite were studied from the Namsan and Tohamsan granites in the vicinity of Kyeongju city, southeastern Korea. The Namsan granite consists of hypersolvus alkali-feldspar granite in the northern part and subsolvus alkali-feldspar to biotite granite in the southern part. This hypersolvus granite usually has miarolitic cavities and is characteristically composed of quartz, single homogeneous one-feldspar (alkali feldspar) forming tabular microperthite crystals, or micrographic intergrowth with quartz, and interstitial biotite (Fe-rich annite), alkali amphibole (riebeckitic arfvedsonite) and fluorite. Petrographic and petrochemical characteristics indicate that the hypersolvus granite and subsolvus granite from the Namsan belogn to the A-type and I-type granitoid, respectively. The A-type granite is petrochemically distinguished from the I-type Bulgugsa granites of Late Cretaceous in South Korea, by higher abundance of $SiO_2$, $Na_2O$, $Na_2O+K_2O$, large highly charged cations such as Rb, Nb, Y, Zr, Ga, Th, Ce. U the REEs and Ga/Al ratio, and lower abundance of $TiO_2$, $Al_2O_3$, CaO, $P_2O_5$, MnO, MgO, Ba, Sr, Eu. The total abundance of REEs is 293 ppm to 466 ppm, showing extensively fractionated granitic compositon, and REEs/chondrite normalized pattern shows flat form with strong Eu '-' anomaly ($Eu/Eu^{\ast}$=0.03-0.05). A-type granite from the Namsan area is thought to have been generated late in the magmatic/orogenic cycle after the production of I-type granite and by direct, high-temperature partial melting of melt-depleted, relatively dry tonalitic/granulitic lower crustal material with underplating by mantle-derived basaltic magmas associated with subduction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.25-33
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• 1994

Temperature dependences of the remanent polarization $P_{\gamma}$/(T), effective birefringence ㅿｎ(T). dielectric constant K(T) and quadratic electro-optic coefficient R(T) of the two-stage sintered xBa(La$_{1/2}$Nb$_{1/2}$)O$_3$Pb$(Zr_{y}Ti_{1-y})O-{3}$(x=0.085, 0.09, 0.40$\leq$y$\leq$0.70)ceramics were investigated. Increasing the PbZrO$_3$ contents, the crystal structure of a specimen was varied from tetragonal and rhombohedral to cubic, and the phase transition was showed a diffuse phase transition(DPT) characteristics. Especially. in the compositions which located on the PE-FE phase boundary were showed a discrepancy between curie temperature and temperature range which a macroscopic polarization and a effective birefringence were disappeared.

• Progress in Superconductivity and Cryogenics
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• v.15 no.4
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• pp.15-20
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• 2013

We investigated the flux pinning properties of both 10 mol% Zr-and Sn-doped $YBa_2Cu_3O_{7-{\delta}}$ (YBCO) films with the same thickness of ~350 nm for a comparative purpose. The films were prepared on the $SrTiO_3$ (STO) single crystal substrate by the metal-organic deposition (MOD) process. Compared with Sn-doped YBCO film, Zr-doped one exhibited a significant enhancement in the critical current density ($J_c$) and pinning force density ($F_p$). The anisotropic $J_{c,min}/J_{c,max}$ ratio in the field-angle dependence of $J_c$ at 77 K for 1 T was also improved from 0.23 for Sn-doped YBCO to 0.39 for Zr-doped YBCO. Thus, the highest magnetic $J_c$ values of 9.0 and $2.9MA/cm^2$ with the maximum $F_p$ ($F_{p,max}$) values of 19 and $5GN/m^3$ at 65 and 77 K for H // c, respectively, could be achieved from Zr-doped YBCO film. The stronger pinning effect in Zr-doped YBCO film is attributable to smaller $BaZrO_3$ (BZO) nanoparticles (the average size ${\approx}28.4$ nm) than $YBa_2SnO_{5.5}$ (YBSO) nanoparticles (the average size ${\approx}45.0$ nm) incorporated in Sn-doped YBCO film since smaller nanoparticles can generate more defects acting as effective flux pinning sites due to larger incoherent interfacial area for the same doping concentration.

• Economic and Environmental Geology
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• v.27 no.1
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• pp.29-39
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• 1994

Gabbroic rocks in which titanomagnetite orebodies are embedded were emplaced in Precambrian metasedimentary rocks. Hornblende K-Ar ages for equigranula and gneissic gabbros were obtained to be $1021.8{\pm}14.5$ Ma and $1468.4{\pm}20.8$ Ma, respectively. Biotite-granite has an age of 116.4 Ma, which has corresponded to Daebo granite. Amphibole minerals of the gabbroic rock and the magnetite orebodies belong to calcic amphibole group such as ferroan pargasite, pargasite, and ferro-pargasite. The gabbroic rocks have unusually high content of $TiO_2$ ranging from 0.88 to 6.03 wt.% with an average value of 3.46 wt.% as compared to normal gabbroic rock with 1.32 wt.% in $TiO_2$. Incompatible elements such as Ba and Sr of the gabbros are negatively correlated with $SiO_2$. In contrast, Co and Cr have a positive correlation with $SiO_2$, suggesting a normal differentiation trend of gabbroic magma.

• The Journal of the Petrological Society of Korea
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• v.6 no.1
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• pp.1-18
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• 1997

Andesitic pyroclastics and lava flows are deposited as a part of composite volcanoes by Cretaceous volcanic activity in Geojae Island, off the coast of Korea. The andesitic pyroclastics are composed of tuff breccia and lapilli tuff minor intercalated tuff. Lava flows are divided into dense and porphyritic andesite containing phenocrysts of plagioclase, pyroxene, and/or hornblende. The andesitic rocks represent charactersitcs of carc-alkaline BAR association with basalt, basaltic andesite, andesite, and dacite to rhyolite. Major element variations of the volcanic rocks show that $Al_2O_3$, total FeO, CaO, MgO and $TiO_2$ decrease with increasing $SiO_2$ but $K_2O$ and total alkalis increase, and represent differntiation trend of calc-alkaline rock series. In spider diagram, contents of Sr, K, Rb, Ba, and Th are relatively high, but contents of Nb, P, Ti and Cr are low. These petrochemcial characteristics are similar to those of rocks from island arc or continental margein related to plate subduction. Chondrite-normalized REE patterns of volcanic rocks are paralle to subparallel, with LREE enriched than HREE, and show gradual increase of negative Eu anomaly from basalt to dacite and rhyolite, suggesting comagmatic fractional crystallization with minor effects of assimilation and magma mixing. Andesitic rocks are assumed medium-K orogenic andesites that formed in the tectomagmatic environment of subduction zone under normal continental margin arc.