• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.147-150
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• 1998

Since P-ELD(powders type electroluminescent device) phenomena were found by G.Destriau at first In 1936, lots of studying was performed in order to realize surface emission devices and flat panel display as a backlight. Due to the problem of low luminance and color and so on, it was delayed. Recently using electric field and thermal effect which can change it\`s molecular arrangement, it can be developed using photoelectric properties of P-ELD. P-ELD in this study was prepared by casting method. Basic structure is ITO/Phosphor/insulator/Al sheet, each layer was mixed by binder, which concentration 11p(poise) for phosphor, 8p(poise) fort insulator. Dielectric properties was investigated first and emission properties of P-ELD based on ZnS:Mn,Cu/ZnS:Cu,Br mixture. P-ELD prepared in this work exhibits about 100cd/㎡ 1-kHz simusoidal excitation.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.4
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• pp.273-288
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• 2023

The Gubong Au-Ag deposit, which has been one of the largest deposits (Unsan, Daeyudong, Kwangyang) in Korea, consists of eight lens-shaped quartz veins (a mix of orogenic-type and intrusion-related types) that filled fractures along fault zones within Precambrian metasedimentary rock. Korea Mining Promotion Corporation found a quartz vein (referred to as the No. 6 vein with a grade of 27.9 g/t Au and a width of 0.9 m) at a depth of -728 ML by drilling (No. 90-12) conducted in 1989. Korea Mining Promotion Corporation conducted drilling (No. 04-1) in 2004 to investigate the redevelopment's possibility of the No. 6 vein. The author studied the occurrence and chemical composition of chlorite and white mica using wallrock, wallrock alteration and quartz vein samples collected from the No. 04-1 drilling core in 2004. The alteration of studied samples occurs chloritization, sericitization, silicification and pyritization. Chlorite and white mica from mineralized zone at a depth of -275 ML occur with quartz, K-feldspar, calcite, rutile and pyrite in wallrock alteration zone and quartz vein. Chlorite and white mica from ore vein (No. 6 vein) at a depth of -779 ML occur with quartz, calcite, apatite, zircon, rutile, ilmenite, pyrrhotite and pyrite in wallrock alteration zone and quartz vein. Chlorite from a depth of -779 ML has a higher content of Al and Mg elements and a lower content of Si and Fe elements than chlorite from a depth of -275 ML. Also, Chlorites from a depth of -275 ML and -779 ML have higher content of Si element than theoretical chlorite. Compositional variation in chlorite from a depth of -275 ML was mainly caused by phengitic or Tschermark substitution [Al^{3+,VI + Al3+,IV} <-> (Fe²⁺ or Mg²⁺)^VI + (Si⁴⁺)^IV], but compositional variation from a depth of -779 ML was mainly caused by octahedral Fe²⁺ <-> Mg²⁺ (Mn²⁺) substitution. The interlayer cation site occupancy (K+Na+Ca+Ba+Sr = 0.76~0.82 apfu, 0.72~0.91 apfu) of white mica from a depth of -275 ML and -779 ML have lower contents than theoretical dioctahedral micas, but octahedral site occupancy (Fe+Mg+Mn+Ti+Cr+V+Ni = 2.09~2.13 apfu, 2.06~2.14 apfu) have higher contents than theoretical dioctahedral micas. Compositional variation in white mica from a depth of -275 ML was caused by phengitic or Tschermark substitution [(Al³⁺)^VI + (Al³⁺)^IV <-> (Fe²⁺ or Mg²⁺)^VI + (Si⁴⁺)^IV], illitic substitution and direct (Fe³⁺)^VI <-> (Al³⁺)^VI substitution. But, compositional variation in white mica from a depth of -779 ML was caused by phengitic or Tschermark substitution [(Al³⁺)^VI + (Al³⁺)^IV <-> (Fe²⁺ or Mg²⁺)^VI + (Si⁴⁺)^IV] and direct (Fe³⁺)^VI <-> (Al³⁺)^VI substitution.

• Journal of the Korean Ceramic Society
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• v.19 no.4
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• pp.287-292
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• 1982

Nonohmic properties of ZnO ceramics with various small amounts of additives were studied in relation to experimental methods, additive contant and sintaring temperature. The kinds of additives used to following chemicals were basic additives ($0.5Bi_2O_3$, $0.3BaCO_3$, $0.5MnCO_3$, $0.5Cr_2O_3$, $0.1KNO_3$), $TiO_2$ and $Al(OH)_3$. Expecially, this study has focused on the effectsof $TiO_2$ and $Al(OH)_3$ in ZnO ceramics with the basic additives. SEM studies indicated that the addition of TiO2 promoted grain growth but retarded grain growth with the addition of $Al(OH)_3$. Also, in the case of calcination of ZnO with $TiO_2$ and ZnO with $Al(OH)_3$ previously, grain size of ZnO with $TiO_2$ was larger and that of ZnO with Al(OH)3 was smaller in comparison to the case with out calcination. From the viewpoint of nonohmic exponent and nonohimic resistance, electrical characteristics of ZnO, $TiO_2$ and the basic additives was more effective than that of ZnO, $Al(OH)_3$ and the basic additives. Nonohmic exponent and nonohmic resistance of ZnO, $TiO_2$ and the basic additives was 11-13 and 40-65 respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.275-280
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• 1997

The experiment was carried out to determine Al tolerance ranges of two rice cultivars(Ilpumbyeo and Hyangmibyeo) during germination and early growth. The amount of 0, 300, 600 and 900ppm Al were treated in the germination media. Plant height and root length of rice cultivars were decreased significantly with Al concentration. The reduction of growth was more remarkable in root than in shoot. Germination rates in all Al concentrations were decreased comparing with untreated control. Two rice cultivars were not different in Al concentrations. As Al concentration was increased, chlorophyll content were decreased. Ca and Mg contents in 300ppm of Al treatment were sharply increased. Free proline contents of both rice cultivars grown at the 300, 600, and 900ppm of Al treatments were increased only in the 3 days after Al treatments.

• Environmental Mutagens and Carcinogens
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• v.25 no.2
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• pp.60-65
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• 2005

The human solute carrier, SLC41Al, is a $Mg^{2}+$ transporter that is regulated by extracellular magnesium. Although intracellular magnesium plays a fundamental role in cellular metabolism, little is known about how $Mg^{2}+$ is taken up and controlled by cells. Magnesium plays a fundamental role in cellular metabolism so that its control within the body is critical. Magnesium homeostasis is principally a balance between intestinal absorption of dietary magnesium and renal excretion of urinary magnesium. The kidney, mainly the distal convoluted tubule, controls magnesium reabsorption. Although renal reabsorption is under the influence of many hormones, selective regulation of magnesium transport is due to intrinsic control involving transcriptional processes and synthesis of transport proteins. Using microarray analysis, identification of the genetic elements involved with this transcriptional control has been begun. SLC41A1(GenBank Accession No. AJ514402), comprises 10 putative transmembrane domains, two of which are highly homologous to the integral membrane part of the prokaryote transports $Mg^{2}+$ and other divalent cations $Sr^2+,\;Zn^2+,\;Cu^2+,\;Fe^2+,\;Co^2+,\;Ba^2+,\;and\;Cd^2+,\;but\;not\;Ca^2+,\;Mn^2+,\;and\;Ni^2+.$ Transport of $Mg^{2}+$ by SLC41Al is rheogenic, voltage dependent, and not coupled to Na or Cl. Expressed SLC41Al transports a range of other divalent cations: $Mg^{2+},\;Sr^{2+},\;Zn^{2+},\;Cu^{2+},\;Fe^{2+},\;Co^{2+},\;Ba^{2+},\;and\;Cd^{2+}$. The divalent cations $Ca^{2+},\;Mn^{2+},\;and\;Ni^{2+}$and the trivalent ion $Gd^{3+}$ did not induce currents nor did they inhibit $Mg^{2+}$ transport. The nonselective cation $La^{3+}$ abolishes $Mg^{2+}$ uptake. Computer analysis of the SLC41Al protein structure reveals that it belongs to MgtE protein family & suggested that the human solute carrier, SLC41Al, might be a eukaryotic $Mg^{2+}$ transporter closely related $(60-70\%)$ protein encoded by SLC41A2 is a $Mg^{2}+$ transporter that might be involved in magnesium homeostasis in epithelial cells also transports a range of other divalent cations: $Ba^2,\;Ni^2,\;CO^2,\;Fe^2,\;or\;Mn^2,\;but\;not\;Ca^2,\;Zn^2,\;or\;Cu^{2+}$ that may have related functional properties.

• Corrosion Science and Technology
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• v.9 no.6
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• pp.259-264
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• 2010

In continuous hot dip galvanizing process, oxide formation on steel surface has an influence on Zn wetting. High strength automotive steel contains high amount of Si and Mn, where Si-Mn composite oxides such as $Mn_2SiO_4$ or $MnSiO_3$ covers the surface after annealing. Zn wetting depends on how the aluminothermia reaction can reduce the Mn-Si composite oxides and then form inhibition layer such as $Fe_2Al_5$ on the steel surface. The outward diffusion of metallic ions such as $Mn^{2+}$, $Si^{2+}$ in the steel matrix is very important factor for the formation of the surface oxides on the steel surface. The surface state and grain boundaries provide an important role for the diffusion and the surface oxide reactions. Some elements such as P, Sb, and B have a strong affinity for the interface precipitation, and it influence the diffusivity of metallic ions on grain boundaries. B oxide forms very rapildly on the steel surface during the annealing, and this promote complex oxides with $SiO_2$ or MnO. P has inter-reacted with other elements on the grain boundaries and influence the diffusion through on them. Small addition of Sb could suppress the decarburization from steel surface and retards the formation of internal and external selective oxides on the steel surface. Interface control by the trace elements such as Sb could be available to improve the Zn wettability during the hot dip galvanizing.

• Journal of the Korean Magnetics Society
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• v.16 no.2
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• pp.136-139
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• 2006

The tunneling magnetoresistance (TMR) ratios of magnetic tunnel junctions (MTJs), in general, decrease abruptly above 250$^{\circ}C$ due to Mn interdiffusion from an antiferromagnet IrMn layer to a ferromagnetic CoFe and/or a tunnel barrier. To improve thermal stability, we prepared MTJs with nano-oxide layers. Using a MTJ structure consisting of underlayer CoNbZr 4/bufferlayer CoFe 10/antiferromaget IrMn 7.5/pinned layer CoFe 3/tunnel barrier AlO/freelayer CoFe 3/capping CoNbZr 2 (nm), we placed a nano-oxide layer (NOL) into the underlayer or bufferlayer. Then, the thermal, structural and magneto-electric properties were measured. The TMR ratio, surface flatness, and thermal stability of the MTJs with NOLs were promoted.

• Journal of Powder Materials
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• v.15 no.2
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• pp.142-147
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• 2008

The hypereutectic Al-20 wt%Si powders including some amount of Cu, Fe, Mg, Mn were prepared by a gas atomization process. In order to get highly densified Al-Si bulk specimens, the as-atomized and sieved powders were extruded at $500^{\circ}C$, Microstructure and tensile properties of the extruded Al-Si alloys were investigated in this study. Relative density of the extruded samples was over 98%. Ultimate tensile strength (UTS) in stress-strain curves of the extruded powders increased after T6 heat treatments. Elongation of the samples was also increased from 1.4% to 3.2%. The fracture surfaces of the tested pieces showed a fine microstructure and the average grain size was about $1{\mu}m$.

• Journal of the Korean Electrochemical Society
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• v.19 no.4
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• pp.123-128
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• 2016

In this study, poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP)-based gel polymer electrolyte incorporating nano-size $Al_2O_3$ ceramic particle was prepared by electrospinning. The gel polymer electrolyte (GPE) incorporated with $Al_2O_3$ ceramic particle showed higher ionic conductivity of $9.5{\times}10^{-2}Scm^{-1}$ than pure PVdF-HFP GPE without ceramic particle and improved the electrochemical stability up to 5.2 V. The GPEs were assembled with $LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$ (NMC) cathode for electrochemical test. The GPE batteries at 0.1 C-rate delivered $168.2mAh\;g^{-1}$ for pure GPE and $189.6mAh\;g^{-1}$ for hybrid GPE, respectively. Therefore, the incorporation of high dielectric constant ceramic particle will be good strategy to enhance the stability and electrochemical properties of lithium ion gel polymer batteries.

• Journal of the Korean Magnetics Society
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• v.13 no.2
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• pp.47-52
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• 2003

Ferromagnetic tunnel junctions were fabricated by dc magnetron sputtering and plasma oxidation process. The local transport properties of the ferromagnetic tunnel junctions were studied using contact-mode Atomic Force Microscopy (AFM) and the local current-voltage analysis. Tunnel junctions with the structure of sub./Ta/Cu/Ta/NiFe/Cu/Mn$\_$75/Ir$\_$25//Co$\_$70/Fe$\_$30//Al-oxide were prepared on thermally oxidized Si wafers. Al-oxide layers were formed with microwave excited plasma using radial line slot antenna (RLSA) for 5 and 7 sec. Kr gas was used as the inert gas mixed with $O_2$ gas for the plasma oxidization. No correlation between topography and current image was observed while they were measured simultaneously. The local current distribution was well identified with the distribution of local barrier height. Assuming the gaussian distribution of the local barrier height, the ferromagnetic tunnel junction with longer oxidation time was well fitted with the experimental results. As contrast, in the case of the shorter time oxidation junction, the current mainly flow through the low barrier height area for its insufficient oxygen. Such leakage current might result in the decrease of tunnel magnetoresistance (TMR) ratio.