• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.696-702
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• 2018

Recently, the current thermal battery technology needs new materials for electrodes in the power and energy density to meet various space and defense requirements. In this paper, to replace the pellet type Li(Si) anode having limitations of the formability and capacity, electrochemical properties of the lithium anode with high density for thermal batteries were investigated. The lithium anode (Li 17, 15, 13 wt%) was fabricated by mixing the molten lithium and iron powder used as a binder to hold the molten lithium at $500^{\circ}C$. The single cell with 13 wt% lithium showed a stable performance. The 2.06 V (OCV) of the lithium anode was significantly improved compared to 1.93 V (OCV) of the Li(Si) anode. Specific capacities during the first phase of the lithium anode and Li(Si) were 1,632 and $1,181As{\cdot}g^{-1}$, respectively. As a result of the thermal battery performance test at both room and high temperatures, the voltage and operating time of lithium anode thermal batteries were superior to those of using Li(Si) anode thermal batteries. The power and energy densities of Li anode thermal batteries were also remarkably improved.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.79-82
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• 2003

This paper describes a new low-swing inverter for low power consumption. To reduce a power consumption, an output voltage swing is in the range from 0 to $V_{ref}-V_{TH}$, where $V_{ref}=V_{DD}-nV_{TH}$. This can be done by the inverter structure that allow a full swing or a swing on its input terminal without leakage current. Using this low-swing voltage technology, we propose a low-power $4\times4$ bit parallel multiplier. The proposed circuits are simulated with HSPICE under $0.35{\mu}m$ CMOS standard technology. Compare to the previous works, this circuit can reduce the power consumption rate of 11.2% and the power-delay product of 10.3%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.8
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• pp.637-640
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• 2009

In this work, we demonstrate 800 V 4H-SiC power DMOSFETs with several structural alterations to obtain a low threshold voltage ($V_{TH}$) and a high figure of merit ($V_B\;^2/R_{SP,ON}$), To optimize the device performance, we consider four design parameters; (a) the doping concentration ($N_{CSL}$) of current spreading layer (CSL) beneath the p-base region, (b) the thickness of p-base ($t_{BASE}$), (c) the doping concentration ($N_J$) and width ($W_J$) of a JFET region, (d) the doping concentration ($N_{EPI}$) and thickness ($t_{EPI}$) of epi-layer. These parameters are optimized using 2D numerical simulation and the 4H-SiC DMOSFET structure results in a threshold voltage ($V_{TH}$) below $^{\sim}$3.8 V, and high figure of merit ($V_B\;^2/R_{SP,ON}$>$^{\sim}$200 $MW/cm^2$) for a power MOSFET in $V_B\;^{\sim}$800 V range.

• Economic and Environmental Geology
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• v.29 no.6
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• pp.689-698
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• 1996

The coal-bearing metapelites from the Hoenam area are interbedded within the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with trace amount of biotite, chlorite, pyrite, rutile and barite. Although the formation was mined for coal, and the contents of V, U and Mo are a higher grade in coal formations than the host metapelites. The ratios of Al/Na and K/Na in coal formation are very heterogeneous and wide range from 10.28 to 90.91 and from 3.73 to 36.60, respectively. The V content increase with increasing Al and Ba contents, but the U and Mo are not related with other elements. Those are suggested that controlled of mineral compositions in coaly metapelites due to substitution, migration and reequilibrium of elements by regional metamorphism. 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 content versus La, La against Ce, the ratios of La/Ce (0.23 to 0.73) and Th/U (0.03 to 16.6). These rocks also show much variation in $La_N/Yb_N$ (0.53 to 14.19), Th/Yb (0.51 to 6.00) and La/Th (0.15 to 18.92), and their origin is explained by derivation from a mixture of sedimentary and metasedimentary rocks. The wide range in trace and REE element characteristics as Co/Th (0.07 to 3.00), La/Sc (0.04 to 23.48), Sc/Th (0.06 to 7.57), V/Ni (2 to 3319), Cr/V (0.03 to 1.06) and Ni/Co (1.00 to 79.85) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation.

• Ocean and Polar Research
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• v.22 no.1
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• pp.37-43
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• 2000

Epiphytic communities on marine plants of Seychelles (Indian Ocean Island group associated with East Africa) were investigated in January - March of 1989 during the $15^{th}$ biological voyage of the research vessel cademic Alexander Nesmeyanov. A seagrass species, Thalassodendron ciliatum, and macroalgae (Sargassum spp. and Halimeda spp.) were tested for host substrates and biomass of their dominant epiphytes were assessed. Also, in order to understand the effect of shading and nutrient filtering by epiphytes, two series of photosynthetic rates were compared for Th. ciliatum host leaves having 10% and no epiphytes. Total of 84 species of algae and main taxons of benthic animals were identified from three different host plants. An average biomass of the epiphytes on Th. cihiatum was $184.6g\;kg^{-1}$ and dominant species were green alga Halimeda opuntia, red algae Dictyurus occidentalis and Gelidiella myrioclada. These dominant species and their biomass were remarkably varied with depth increment. On Sargassum spp., an average biomass of the epiphytes was $0.18g\;kg^{-1}$ and the maximum biomass was never exceeded $0.16g\;kg^{-1}$. In the case of Halimeda spp. an average biomass of the epiphytes was $8.0g\;kg^{-1}$, and dominant species were Peyssonnelia dubyi, sponges and decapods. Photosynthetic rates of Th. ciliatum were significantly reduced in the leaves having 10% epiphytes (1.72 times lower, t=6.718, p<0.001).

• Korean Journal of Animal Reproduction
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• v.12 no.1
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• pp.31-36
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• 1988

There studies were conducted using inbred ICR mice to examine the sex of preimplantation mouse embryo. The morphological normality of mice embryos treated with the culture medium containing rat H-Y antiserum(10%, v/v) plus complement(20%,v/v) was observed and also the sexing of embryos was investigated by chromosomal analysis. The results obtained were summarized as follows: 1. The viability of preimplantation mouse embryos, which were incubated in vitro with different media condition, was scored 68.9-85.5% in control group. However, 151 embryos normally developed up to blastocyst and 160 embryos were retarded growth or destroyed out of total 311 embryos treated in the medium containing H-Y antiserum(10%, v/v) plus complement(20%,v/v). 2. H-Y antiserum was prepared from inb red rats (Wistar and Donryu strain) with different immunization times (4, 5 and 6th) to examine the specific titer of embryos by the number of immunization. Precentage of normally developed embryos incubated either in the medium containing the antiserum of Wistar plus complement or Donryu plus complement was revealed 50.9, 47.4 and 50.0% (4, 5 and 6th immunization and 47.8, 41.2 and 48.7%, respectively. 3. Twenty two females and five males were identified out of fourty-eight normally developed embryos incubated in the medium containing H-Y antiserum plus complement by chromosomal analysis.

• Economic and Environmental Geology
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• v.42 no.3
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• pp.195-206
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• 2009

We investigated natural background and enrichment characteristics and predicted geochemical disaster for stream sediments in the Hamyang-Sancheong area. Stream sediments samples were collected 95 ea in study area. The stream sediments were well known that had not possibility of contamination effect and represented drainage basins. We got the major and hazardous elements concentrations by XRF, ICP-AES and NAA analysis methods. Acid decomposition for the ICP-AES has been used $HClO_4$ and HF with $200^{\circ}C$ heating at 1st and after that $HClO_4$ HF and HCl with $200^{\circ}C$ heating at 2nd stage. We could know the characteristics that concentration of Cu and Co decreased when concentration of $SiO_2$ increased in correlation analysis. The enrichment factor of the stream sediments was below 2 in study area. This result indicated that study area belonged to moderate enrichment. The stream sediments of Hamyang area were enriched in order of Pb>Th>Cr>V>Co>Cu and those of Sancheong area were enriched in order of Pb>Th>Cr>Co>V>Cu. The enrichment factor(E.F.) of the Pb, Cr, Co and V was similar between Hamyang and Sancheong area. The enrichment factor of the Th was higher in Hamyang area and that of the Cu was higher in Sancheong area. The enrichment factor of the Pb was highly enriched in all study area than earth crust mean. But we could know that study area was not exposed to the pollution of the Pb through the tolerable level.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1453-1454
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• 2011

We have investigated the effect of silicon contents (0~0.4 molar ratios) on the performance of solution processed silicon-indium-zinc oxide (SIZO) thin-film transistors (TFTs). Despites its solution processed channel layer, low annealed temperature below $200^{\circ}C$ in air has been used for SIZO-TFTs. The $V_{th}$ is shifted from -4.04 to 5.15 V as increasing Si ratio in the SIZO-TFTs. The positive shift of $V_{th}$ as increasing Si contents in SIZO system indicates that Si suppresses the carrier generation in the active channel layer since $V_{th}$ is defined as the voltage required accumulating sufficient charge carriers to form a conductive channel path.

• Journal of Sericultural and Entomological Science
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• v.35 no.1
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• pp.69-72
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• 1993

Effects of topical application with 1, 5 and 10 ${\mu}$g/ml testosterone on the precocooning and post cocooning traits of the polyvoltine. Pure Mysore breed of silkworm were studied. Each concentration was treated independently at 36th to III, IV and V instar larvae(Treatment-1), at 48th to IV and V instar larvae(Treatment-2_ and at 72th to V instar larvae(Treatment-3). The repeated application with each concentration of testosterone propionate in treatment, and 2 larvae or single application in treatment 3 variously affected the precocooning and post cocooning traits. Repeated applications of all doses of testosterone propionate(Treatment-1) and single application of 1 & 5 ${\mu}$g of the chemical(Treatment-3) increase the fecundity and decrease the percentage of cocooning and moth emergence.

• Korean Journal of Environment and Ecology
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• v.18 no.4
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• pp.382-391
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• 2004

This study was conducted to establish the effective and systematic counter plan of conservation by analyzing vegetation on Korean endemic plants and rare and endangered plants, Abeliophyllum distichum, habitats and to present the raw data and direction on counter plan of restoration. The dominant species of tree layers were Platycarya strobilacea(Goesan-gun Chujeom-ri I), Pinus densiflora(Goesan-gun Songdeok-ri II and Yulji-ri III), Robinia pseudo-acacia(Yeongdong-eup Maechon-ri IV), Quercus variabilis(Jincheon-gun Yongjeong-ri V) and Pinus densiflora$.$Quercus variabilis(Buan-gun Junggye-ri Ⅵ). Subtree layers were dominated by Quercus dentata(1st site), Quercus serratu(2nd site), Quercus acutissima(3rd site), Robinia pseudo-acacia(4th site), Zelkova serrata(5th site) and Quercus variabilis(6th site). And the dominant species of shrub layers were Lindera obtusiloba(1st and 5th site), Lespedeza bicolor(2nd site), Stephunandra incisa(3rd site), Quercus aliena(4th site) and Rhododendron schlippen-bachii(6th site). The dominant species of herb layers were surveyed Humulus japonicus$.$Pueraria thunbergiana(1st site), Oplismenus undulatifolius(2nd and 4th site), Carex siderosticta$.$Pueraria thunbergiana(3rd site), Streptolirion cordifolium$.$Humulus japonicus(5th site) and Sasa borealis(6th site). Among the surveyed sites, the Goesan-gun Yulji-ri supremely abounded in species and individuals, and there was surveyed each 21 species and 116 individuals. As well, this site showed the highest H'(1.123) and H'$_{max}$(1.322). Therefore, Goesan-gun Yulji-ri formed diverse vegetation and Yeongdong-eup Maechon-ri and Buan-gun Junggye-ri showed relatively poor vegetation.ation.