• Korean Journal of Plant Resources
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• v.12 no.2
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• pp.145-151
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• 1999

This study was conducted to know the influence of transplanting dates on yield and chemical component of colored rice varieties at Taejon area in middle part in Korea. The late transplanting led to late heading in which the latest transplanting on June 18 headed on August 9 in Heugiinjubyeo and on August 24 in Heugnambyeo, respectively, which in the safe latest heading date at Taejon area. The highest yield was attained by middle of June transplanting in Heugjinjubyeo, while that for the Heugnambyeo was transplanting from end of May to beginning of June. The relative optical density(ROD) of the pigment measured at 530 nm was higher in Heugjinjubyeo than that of Heugnambyeo. The late transplanting increased the ROD in Heugnambyeo, while later than May 28 decreased the ROD in Heugjinjubyeo. There was a varietal difference in cation contents such as K, Ca, Mg and Fe. The Contents of the former three was not influenced by different transplanting dates, while the Fe content was increased by early transplanting.

• Journal of the Mineralogical Society of Korea
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• v.29 no.3
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• pp.141-153
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• 2016

The Manjang deposit is emplaced in Hwajeonri formation comprising limestone that is interbeded with slate and phyllite in the central Okcheon Group. It consists of the Main and the Central orebody of Cu-bearing hydrothermal vein deposit and the Western orebody of iron skarn deposit. Based on coexisting mineral assemblage the skarnization can be divided into prograde skarnization (stage I : clinopyroxene ${\pm}$ magnetite ${\pm}$ quartz, stage II : garnet + clinopyroxene ${\pm}$ magnetite ${\pm}$ quartz) and retrograde hydrothermal alteration (stage III: magnetite + amphibole + quartz ${\pm}$ garnet ${\pm}$ clinopyroxene ${\pm}$ chlorite ${\pm}$ epidote ${\pm}$ fluorite ${\pm}$ calcite, stage IV: fluorite ${\pm}$ pyrrhotite ${\pm}$ chalcopyrite ${\pm}$ amphibole ${\pm}$ quartz ${\pm}$ calcite). Diopside is abundant in stage I, and hedenbergite was produced in stage II and III. Garnet compositions change from grandite to andradite, which suggests a redox transition from relatively reduced to oxidized condition during the skarn formation. Magnetite in stage I and II has relatively constant Fe contents, while in the stage III it has increased Si and Ca concentrations. This variation could indicate that magnetite was more strongly affected by host rocks during the retrograde stage. Sulfur isotope compositions of pyrrhotite and chalcopyrite produced in stage IV are within the range of + 5.9~6.9 ‰, corresponding to igneous origin, but slightly high sulfur isotope values could be attributed to an interaction with host rocks, limestone.

• Journal of Mushroom
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• v.3 no.3
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• pp.100-104
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• 2005

We investigated mineral difference from mushroom Phellinus linteus and Phellinus baumii on mulberry, oak and elm. ICP test, The major mineral components were K, Ca, and Fe, while Mg, Na, P, Cr, Mn, Cu and Zn were determined as micro mineral components. In case of P.linetus and P.baumii the component of K was shown as 699.0mg/100g and 630mg/100g, in oak, 340.7mg/100g and 314.6mg/100g in elm, and 311.6mg/100g and 311.6mg/100g in mulberry respectively. In Ca, mulberry fruiting body were shown about 2 times highest and expecially in case of Na was oak fruiting body were shown as 10 times highest as against the others sample groups. In micro mineral components, Zn component was shown very diffeence about sample groups. We concluded that the highest mineral component of K was shown in mushroom cultivated on oak of both P.linetus and P.baumii. As a results, mineral component has showed very difference on cultivated to timber. According to the results of mineral component we concluded that Phellinus linteus and Phellinus baumii has mineral component different depending on timber.

• Journal of the Korean GEO-environmental Society
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• v.5 no.2
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• pp.23-31
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• 2004

Trichloroethylene(TCE), Cr(VI), and nitrate removal efficiency of a novel reactive barrier were experimented, and the types of corrosion species that form on the surface of the iron and bentonite as a result of reaction were investigated with Raman spectrophotometer. The reactive barrier is composed of bentonite and zero valent iron(ZVI), and this can substitute conventional geosynthetic clay liners for landfill leachate. Tests were performed in batch reactors for various ZVI content (0, 3, 6, 10, 13, 16, 20, 30, 100 w/w %) and pH. The reduction rates and removal efficiencies of TCE, Cr(VI) and nitrate increase at pH 7 buffered solution. As ZVI content increases, TCE, Cr(VI) and nitrate removal efficiencies increase. From the result of analysis with Raman spectrophotometer, Fe-oxides were observed, which are strong adsorbers of cantaminants. Magnetite can be also beneficial to the long term performance of the iron metal.

• Journal of the Korean Magnetics Society
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• v.25 no.2
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• pp.39-42
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• 2015

After preparing carbon-doped FePt films by dc magnetron sputtering, we observed ultrafast demagnetization and its recovery by means of a time-resolved magneto-optical Kerr effect technique. We confirm that the degree of $L1_0$ ordering is decreased and coercivity is changed, as the carbon concentration increases. All samples are demagnetized within ~5 ps after the femtosecond laser pulse heated the sample. Interestingly, ultrafast relaxation time, which indicates fast magnetization recovery, increases as the carbon concentration increases due to the low spin-orbit coupling of carbon.

• Journal of the Korean Magnetics Society
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• v.12 no.1
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• pp.7-13
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• 2002

The studies of non-figure plain coarse pottery from Jeju island is very important because it can explain the characters of plain coarse potteries of the bronze age and the early iron age. In this study, We analyzed the non-figure plain coarse popery from Jeju island in two ways. One is analysis of the chemical composition using X-ray fluorescence spectrometer and X-ray diffraction, the other is analysts of clay mineral contained iron, oxidized iron's genus, valence state and magnetic properties using Mossbauer spectroscopy. We confidence that non-figure plain coarse pottery is chiefly made of silicate minerals, like SiO$_2$. The content of noncrystalline ferrihydrite is supposed to be below 5-10 wt%, non-figure plain coarse pottery is considered to partly consist of Jeju island clay, which is made of neutral volcanic rock and the valence state of iron is Fe$\^$2+/ and Fe$\^$3+/. We presume the reason that the magnetic hyperfine field is lower than that of pure goethite is the change of crystal structure which transforms the combination states of Fe ions while the clay is being fired.

• Journal of the Korean earth science society
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• v.23 no.8
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• pp.697-706
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• 2002

Authigenic siderite grains, ranging 100 to 250-${\mu}$m in diameter, are abundant in an about 8,600-year-old sediment layer in Namyang Bay, west coast of Korea. The siderites exhibit the aggregated spherulitic morphology with well-developed rhombs on the grain surfaces. They consist mostly of FeCO$_3$ (average, 65%) and MnCO$_3$ (average, 22%) with low Mg/Ca ratio (less than 0.4) in their bulk composition. A series of compositional ternary discrimination diagrams, together with high Mn and low Mg contents, show that only meteoric porewater was involved in siderite precipitation, assuming that depositional environment of host sediment is an organic-rich freshwater system. Considering a series of results such as radiocarbon age, authigenic Mn-rich siderite and lithological features, siderite-hosting sediment (unit Tl) is interpreted as freshwater swamp or bog deposition, infilling the topographic depressions that locally existed before the formation of mid-to-late Holocene tidal deposits. Center-to-margin compositional variation within individual grain is very systematic; Mn and Ca decrease towards the margin of a siderite grain, while Fe and Mg increase. It suggests that the spherulitic siderites were precipitated in this sedimentary layer in a series during the early diagenesis of MnOx-FeOx reduction under steady-state.

• Journal of the Korean earth science society
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• v.35 no.6
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• pp.422-428
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• 2014

Korea Institute of Geoscience and Mineral Resources (KIGAM) and Mineral Resources Authority of Mongolia (MRAM) performed a joint survey on Ugii Nuur Fe-Mn mineralized area. Following the survey, we carried out magnetic survey and 3D magnetic susceptibility inversion. Based on the inversion results, basic feasibility study and 3D imaging of Fe-Mn mineralized area were performed using 3D geological modeling technique. Using the distribution of total magnetic field data, we were confirmed for the possibility of horizontal extension of ore bodies from surface outcrops. The 3D magnetic susceptibility model, which is highly related with Fe content, analyzed by inversion shows that the ore bodies of Deposit 1 and Deposit 2 are extended to the underground and ore bodies that are not exposed on the surface are largely distributed in the underground. If we perform the integration analysis using this magnetic susceptibility model and the ore grade data analyzed by drilling survey, it is possible to carry out the effective potential evaluation of Ugii Nuur Fe-Mn ore deposit.

• Resources Recycling
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• v.30 no.4
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• pp.27-34
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• 2021

In this study, the leaching behavior of vanadium (V) was investigated through CaO roasting and sulfuric acid leaching from domestic V-bearing titanomagnetite (VTM). Changes in the phase according to the amount of CaO added and roasting temperature were analyzed. Regardless of the roasting conditions, perovskite (CaTiO₃) was preferred to form. When the CaO content was increased, the calcium ferrite (CaFeO_x) phase was formed; otherwise, ferrite (Fe₂O₃) was preferred. After CaO was roasted, leaching was performed for 6 h with 1M sulfuric acid at 50℃ and a 10% solid-liquid ratio. Results of leaching revealed that when the roasted product was sintered, V was not sufficiently oxidized, and the leaching efficiency decreased. In addition, when the roasting temperature was low, the leaching efficiency of V decreased due to the influence of unreacted excess CaO. To lower the leaching efficiency of iron and titanium in VTM concentrates, suppressing the formation of CaTiO₃ and CaFeO_x was necessary by minimizing the amount of CaO added. Consequently, a leaching efficiency of 86% V, 4.3% Fe, and 6.5% Ti was obtained when the roasted product of 1150℃ and 10 wt% CaO was leached.

• 한국해양학회지
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• v.29 no.4
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• pp.338-356
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• 1994

Sediment samples from the continental shelf of the South Sea of Korea are analysed to determine the concentration of Al, Fe, Mn, cu, Ni, Zn, Co, Cr and Pb. among these samples, fine-grained sediments were also analysed by a sequential extraction technique to know geochemical forms of the metals in this environments. The total concentration of Al, Fe, Cr, Ni, Cu and Zn in bulk sediments decreased gradually with the increase of distance from the coastal zone. This distribution patterns are well coincide with grain size distribution. However, the patterns of Mn, co and Pb do not follow such and overall distribution. The concentration of Pb, particularly, did not show any features in areal distribution, which may be result from different pathways to the sediments, compared to the other metals. the speculation data show that a considerable amount of Cd, Mn and Co are bounded in the carbonate fraction, accounting for 42.8%, 40.3% and 30.6%, respectively. Cu, Zn, Mn and Fe are largely associated to oxide fraction with proportions of 34.4%, 23.1%, 15.5% and 13.7%, respectively. However, the metals in residual fraction account for more than 50% of the total metal concentration, except for Mn. These observations emphasize that residual fraction in the dominant component controlling the elemental concentration.quartz and glauconite grains.Accordingly,these sediments are interpreted as an extension part of transgressive sand deposit that are widely distributed on the continental shalf floor of southern Yellow Sea.