• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.75-84
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• 2005

The aim of this study is to evaluate the leaching characteristics of lead, copper, cadmium, and mercury from steel making slag by seawater. To demonstrate the leaching characteristics of heavy metals from steel making slag by seawater, it was carried to various leaching tests such as regular leaching tests, liquid/sold(LS) leaching test and pH static test. From the leachability of $Pb^{+2},\;Cu^{+2},\;and\;Cd^{+2}$ from steel making slag in pH static test, it is distinguished between distilled water and seawater. With distilled water, it is very low between pH 7-8 and pH 11-12. On the other hands, with the seawater, its leaching is higher than that of distilled water. In particular, concentration of $Hg^{+2}$ leached from slag by seawater is lower than that of distilled water. Meanwhile, we found that the heavy metals from steel making slag would be dissolved and precipitated using geochemcial equilibrium program such as visual minteq. Lead and copper leached from steel making slag with seawater were dissolved nearly in the range of pH 11-12, but in the range of pH 7-10 those were precipitated about 90%. And cadmium leached from steel making slag with seawater were dissolved completely. On pH static test with distilled water, lead leached from steel making slag seemed to be similar to pH static test with seawater. However, copper and cadmium leached from steel making slag were dissolved. In general, the species of lead leached from steel making slag were formed mainly of $PbCl^+,\;PbSO_4$, the species of copper were formed mainly of $CuSO_4,\;CuCO_3$, the species of cadmium were formed mainly of $CdCl^+,\;CdSO_4$ due to being sorbed with the anions($Cl^-,\;CO_3^{-2},\;SO_4^{-2}$) of the seawater. Both pH static test with seawater and distilled water, it is not in the case of the mercury. Most of mercury leached from steel making slag was precipitated(SI=0). Because the decreasing of $Hg^{+2}$ concentrations depends ferociously on the variation of chloride($Cl^-$) existed in the seawater. $Hg^{+2}$ leached from steel making slag could be sorbed strongly with chloride($Cl^-$) compared of carbonate($CO_3^{-2}$) and sulfate($SO_4^{-2}$) in the seawater. On the basis of that result, we found that the species of mercury was formed of calomel($Hg_2Cl_2$) as one of finite solid. Due to forming a calomel($Hg_2Cl_2$) in the seawater, the stability of mercury species by steel making slag should be higher than those of lead, copper, and cadmium species. Regarding the results stated above, we postulated that the steel making slag could be recycled to sea aggregates due to being distinguishing leachability of heavy metals($Pb^{+2},\;Cu^{+2},\;Cd^{+2},\;and\;Hg^{+2}$) between leaching tests by distilled water and seawater.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.402-411
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• 2012

Natural Bokbunja is used as a material of oriental medicine which it obtains from Rubus or Raspberry. Natural Bokbunja Rubus has natural odor and taste, natural color, and pharmaceutical & chemical characteristics. This experiment tested antimicrobial experiment against microbe and dye experiment against fiber using natural Bokbunja extract. Some conclusions from this characteristics experiment were obtained as follow. The result of antimicrobial experiment could know that ATCC-001(staphylococcus aureus) does not show nearly from 72hrs after cultivation test and ATCC-002(aspergillus niger) shows to propagate continuously according to passage of time. Also, the result of dye experiment could know that cotton and silk using alum mordant($Al_2(SO_4)_3{\cdot}13-14H_2O$) against fiber shows in direction of light beige color. The result of instrument analysis ascertained inorganic components of K(221.100ppm), Mg(17.920ppm), Ca(5.129ppm), Na(2.940ppm), Si(0.638ppm) etc from Bokbunja with ICP/OES, and ascertained organic components of boric acic(1.711), silane(2.142), pyrazole(3.481), propyl isothiocyanate(2.565), furfurole(11.521) etc from Bokbunja with GC/MSD.

• Journal of the Korean Magnetics Society
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• v.10 no.5
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• pp.203-209
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• 2000

Top synthetic spin valves with structure Ta/NiFe/CoFe/Cu/CoFe(P 1)/Ru/CoFe(P2)/FeMn/Ta on Si (100) substrate with natural oxide were prepared by dc magnetron sputtering system. We have changed only the thickness in free layers and the thickness difference (Pl-P2) in two ferromagnetic layers separated by Ru, and investigated the effect of magnetic film thickness on interlayer coupling field in spin valve with synthetic antiferromagnet. According to the decrease of free layer thickness, interlayer coupling field was increased due to the magnetostatic coupling(orange peel coupling). In case of t$\_$P1/>t$\^$P2/, interlayer coupling field agreed well with the modified Neel model suggested in conventional spin valve structures by Kools et al. However, in case of t$\_$P1/>t$\^$P2/, it was found that the interlayer coupling field was not explained by the Modified Neel Model and was confirmed the necessity of further remodeling. The dependence of Cu thickness on the interlayer coupling field was investigated and 10 Oe of interlayer coupling field was obtained when the Cu thickness is 32 $\AA$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.12
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• pp.1008-1015
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• 2002

The fabricated La-modified lead titanate (PLT) thin film without poling treatment was investigated for modulation frequency dependence of pyroelectric properties by the dynamic method. $Pb_{l-x}La_{x}Ti_{l-x/4}O_3$(x=0.1) (PLT(10)) thin film haying 10 mol% La content was deposited on a Pt/$TiO_{x}$/$SiO_2$/Si substrate by sol-gel method. The PLT(10) thin film exhibits a relatively excellent dielectric property. The pyroelectric coefficient (p) of the PLT(10) thin film is 6.6 x $10^{-9}C$$textrm{cm}^2$$.$K without frequency dependence. The figure of merits for the voltage responsivity and specific detectivity are 1.03 x $10^{-11}C$.cm/J and 1.46 x $10^{-10}C$.cm/J, respectively The PLT(10) thin film has voltage responsivity (RV) of 5.IS V/W at 8 Hz. Noise equivalent power (NEP) and specific detectivity ($D^{*}$) of the PLT(10) thin film are 9.93 x $10^{-8}$W/$Hz^{1/2}$ and 1.81 x $10^{6}$cm.$Hz^{1/2}$/W at the same frequency of 100 Hz,, respectively The results means that PLT thin film having 10 mol% La content is suitable for the sensing materials of pyroelectric IR sensors.

• Journal of the Korean Magnetics Society
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• v.20 no.6
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• pp.222-227
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• 2010

$BiFeO_3$ (BFO) thin films were deposited on Pt/Ti/$SiO_2$/Si(100) substrates by RF magnetron sputtering method at room temperature. The influence of the flow rate of $O_2$ gas on the preparation of $BiFeO_3$ thin films was studied. XRD results indicate that the $BiFeO_3$ thin films were crystallized to the perovskite structure with the presence of small amount of impurity phases. The flow rate of $O_2$ gas has great affect on the microstructures and magnetic properties of $BiFeO_3$ thin films. As flow rate of $O_2$ gas increased, roughness and grain size of the thin films increased. $BiFeO_3$ thin films exhibited weak ferromagnetic behavior at room temperature. The PFM images revealed correlation between the surface morphology and the piezoresponse, indicating that the piezoelectric coefficient is related to microstructure.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.73-78
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• 2018

BACKGROUND: Soil salinity of reclaimed tidal land in Korea is highly important factor. High salinity is harmful to crop productivity. Jerusalem artichoke (Helianthus tuberosus L.) is known to be salt-tolerant and has high adaptability to diverse pedo-climatic conditions. The objective of this study was to assess the changes of soil properties and crop productivity according to salt concentration in the reclaimed tidal lands. METHODS AND RESULTS: Experimental sites were selected at Saemangeum ($35^{\circ}46^{\prime}N$, $126^{\circ}37^{\prime}E$) reclaimed tidal land, and their dominant soil series were Munpo (coarse loamy, mixed, non-acid, mesic, typic Fluvaquents). H. tuberosus L were collected from 12 locations across Korea. Tubers were planted at $75{\times}25cm$ with EC 2 to $7dS\;m^{-1}$. Soil samples were periodically collected from both 0~20 cm and 20~40 cm depths of each site. Soil salinity and soil moisture contents were varied depending on weather conditions. Soil electrical conductivity varied from 1.0 to $5.9dS\;m^{-1}$, and soil moisture contents varied from 9.2 to 28.7%. The white-colored tubers of H. tuberosus L. collected from 'Yeongwol-gun' exhibited the highest height (207 cm), followed by the white-colored tubers of H. tuberosus L. collected from 'Iksan-si'(202 cm). The white-colored tubers of H. tuberosus L. collected from 'GyeongJu-si' showed the highest yield (549 kg/10a). The purple-colored tubers of H. tuberosus L. collected from 'Yeongwol-gun' showed the highest yield (615 kg/10a). CONCLUSION: Our results indicate that the plant height and tuber yield did not appear to be correlated. Considering yield and inulin content, the GyeongJu-si seemed to be suitable as the white-colored tubers of H. tuberosus L. and the Yeongwol-gun seemed to be suitable as the purple-colored tubers of H. tuberosus L. in the reclaimed tidal lands. However, it is necessary to consider the relationship between the inulin content and the yield.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.33-33
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• 2009

Silicon nano-structures have great potential in bionic sensor applications. Atomic force microscopy (AFM) anodic oxidation have many advantages for the nanostructure fabrication, such as simple process in atmosphere at room temperature, compatibility with conventional Si process. In this work, we fabricated simple FET structures with channel width W~ 10nm (nanowire) and $1{\mu}m$ (nano-ribbon) on ~10, 20 and 100nm-thinned silicon-on-insulator (SOI) wafers in order to investigate the surface effect on the transport characteristics of nano-channel. For further quantitative analysis, we carried out the 2D numerical simulations to investigate the effect of channel surface states on the carrier distribution behavior inside the channel. The simulated 2D cross-sectional structures of fabricated devices had channel heights of H ~ 10, 20, and 100nm, widths of L ~ $1{\mu}m$ and 10nm respectively, where we simultaneously varied the channel surface charge density from $1{\times}10^{-9}$ to $1{\times}10^{-7}C/cm2$. It has been shown that the side-wall charge of nanowire channel mainly affect the I-V characteristics and this was confirmed by the 2D numerical simulations.

• Macromolecular Research
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• v.14 no.1
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• pp.38-44
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• 2006

Vacuum deposited copper phthalocyanine (CuPc) was placed as a thin interlayer between indium tin oxide (ITO) electrode and a hole transporting layer (HTL) in a multi-layered, organic, light-emitting diode (OLEOs). The well-stacked CuPc layer increased the stability and efficiency of the devices. Thermal annealing after CuPc deposition and magnetic field treatment during CuPc deposition were performed to obtain a stacked-CuPc layer; the former increased the stacking density of the CuPc molecules and the alignment of the CuPc film. Thermal annealing at about 100$^{circ}C$ increased the current flow through the CuPc layer by over 25$\%$. Surface roughness decreased from 4.12 to 3.65 nm and spikes were lowered at the film surface as well. However, magnetic field treatment during deposition was less effective than thermal treatment. Eventually, a higher luminescence at a given voltage was obtained when a thermally-annealed CuPc layer was placed in the present, multi-layered, ITO/CuPc/NPD/Alq3/LiF/AI devices. Thermal annealing at about 100$^{circ}C$ for 3 h produced the most efficient, multi-layered EL devices in the present study.

• Journal of the Korean Society for Heat Treatment
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• v.18 no.4
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• pp.229-234
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• 2005

Effect of incident ion beam energy on microstructure and adhesion behavior of TiN thin films were studied. Without ion beam assist, TiN film showed (111) growth mode which was thought to have the lowest deformation energy. As the ion beam assist energy increased, TiN film growth mode was changed from (111) to (200) mode. On the Si(100) substrate the critical incident energy for growth mode change was 100 eV/atom, however the critical assist energy was 121 eV/atom on the STD61 substrate. Grain size of TiN films increased with the assist ion beam energy. Finally, adhesion strength of TiN films bombarded above the critical ion assist energy showed 4~5 times higher values than that with lower bombard ion energy.

• Korean Journal of Veterinary Service
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• v.45 no.1
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• pp.31-38
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• 2022

Swine influenza (SI) is an important respiratory disease in pigs and epidemic worldwide, which is caused by influenza A virus (IAV) belonging to the family of Orthomyxoviridae. As seen again in the 2009 swine-origin influenza A H1N1 pandemic, pigs are known to be susceptible to swine, avian, and human IAVs, and can serve as a 'mixing vessel' for the generation of novel IAV variants. To this end, the emergence of swine influenza viruses must be kept under close surveillance. Herein, we report the isolation and phylogenetic study of a swine IAV, A/swine/Korea/21810/2021 (sw21810, H3N2 subtype). BLASTN sequence analysis of 8 gene segments of the isolated virus revealed a high degree of nucleotide similarity (94.76 to 100%) to porcine strains circulating in Korea and the United States. Out of 8 genome segments, the HA gene was closely related to that of isolates from cluster I. Additionally, the NA gene of the isolate belonged to a Korean Swine H1N1 origin, and the PB2, PB1, NP and NS genes of the isolate were grouped into that of the Triple reassortant swine H3N2 origin virus. The PA and M genes of the isolate belonged to 2009 Pandemic H1N1 lineage. Human infection with mutants was most common through contact with infected pigs. Our results suggest the need for periodic close monitoring of this novel swine H3N2 influenza virus from a public health perspective.