• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.145-147
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• 2000

The secondary electron emission coefficient y of MgO single crystal according to the gas mix-ture ratio of Xe, $N_2$ to Ne have been investigated by $\gamma$-focused ion beam system. It is found that the MgO single crystals of (111) crystallinity has the highest $\gamma$ for operating Ne(Xe) ions ranging from 50eV to 200eV throughout this experiment. And it is found that the $\gamma$ for gas mixtures are much smaller than pure Ne ions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1594-1596
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• 1997

$LiMn_2O_4$ is prepared by reacting stoichiometric mixture of LiOH $H_2O$ and $MnO_2$ (mole ratio 1 : 2) and calcinating at $800^{\circ}C$ for 24h, 36h, 48h, 60h and 72h. At X-ray diffraction, cathode active materials calcined at $800^{\circ}C$ for 36h. (111)/(311) peak ratio was 0.37. It was that crystal structure is formed very well. In the result of charge/discharge test, when heated at $800^{\circ}C$ for 36h, charge/discharge characteristics of $LiMn_2O_4$ is the best and Super-s-black sort of conductive agent showed well property. Also, AC impedance creased gradually during cycling and stabilized after 10cycle.

• Journal of Ecology and Environment
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• 제35권2호
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• pp.99-109
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• 2012

Litterfall dynamics in forests are assessed by estimating biomass production and decomposition. However, there have been few studies on how litter dynamics impact the health and management of ecosystems. Here, a new approach to measure and assess ecosystem function is presented based on conventional methods using littertraps, litterbags, and the mass on the forest floor. To assess the status of litter dynamics, the decay rate (k) was estimated from a litterbag experiment, and removal rates ($k_i$) were determined from mass balance on the forest floor at 21 sites on three mountains in South Korea. The $k_3$ (organic mass ratio of $O_i$ and $O_e+O_a$ + A horizons in November) values in an equilibrium state in South Korea were within the range of $k{\pm}0.174$ when considering the annual variation of litterfall production. This study also suggests that sampling sites for these types of studies should be in the middle, not at the ends, of steady slopes on the forest floor.

• 한국의류산업학회지
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• 제5권5호
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• pp.545-549
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• 2003

Dyeing properties such as migration of disperse dye and color fastness of 4 types of the carrier[Carrier-I(methyl napthalene). Carrier-II(chloro benzene). Carrier-III(aromatic ether) and Carrier-IV(o-phenyl phenol)] were evaluated for the study. For the results, the optimum dyeing time and concentration of the carrier was 30min at $110^{\circ}C$ and 2g/l, respectively. The redyeing ratio of the fabric samples treated with Carrier-II and III was higher than that treated with Carrier-I and IV, thus, if was conclude that the redyeing ratio of the samples treated with Carrier-II and III was excellent. The light fastness of the samples treated with Carrier-III and IV was higher than that of Carrier-I and II in order of 2-4 grades. However, there were little changes in terms of washing and sublimation and rubbing fastness for the samples.

• 약학회지
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• 제26권4호
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• pp.209-214
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• 1982

Acute toxicities of purified ginseng saponin (PGS) in mice, and sbacute toxicities of PGS in rats were investigated. Average lethal doses ($LD_{50}$) of PGS in male mice were 270mg/kg (i.v.), 342mg/kg (i.p.), 505mg/kg (i.m.), 950mg/kg (s.c.), and more than 5,000mg/kg (p.o.), respectively. Results of subacute toxicity of PGS was as follows. Body weight was markedly increased by administration of PGS 7.7mg/kg but side effects were shown by administration of 77mg/kg and above dose. Especially administration of PGS 240mg/kg caused a marked decrease of albumin/globulin ratio, and 28% increase of urea nitrogen in serum, as well as 33% increase of liver weight/body weight ratio.

• Journal of Animal Science and Technology
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• 제46권1호
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• pp.39-48
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• 2004

본 연구의 목적은 생균제의 지속적인 첨가에 의한 돼지에게 있어 성장능력, 영양소 소화율, 혈중 요소태 질소량 및 면역반응에 미치는 영향을 평가하기 위해 실시하였다. 처리는 대조구, 대조구 사료에 0.1%의 생균제 첨가구(P-O.I), 대조구 사료에 0.2%의 생균제 첨가구 (P-0.2)로 하였다. 사양실험에서는 21 일령에 이유한 총 60마리 의 돼지(펑균 체중 6.17 $\pm$ 0.45 kg)를 공사하여 성별 빛 체중에 따라 난괴법에 의해서 배치하였다. 옥수수 대두박 위주의 실험사료에 전 기간에 걸쳐 항생제는 첨가하지 않고 생균제만을 처리별로 첨가하였다. 0${\sim}$8주간의 사양설험에서는 처리간 일당증체량, 일당사료섭취량 및 사료효율에서 유의한 차이가 나타나지 않았다 하지만 9${\sim}$20주에서는 P-O.I과 P-0.2 처리구가 대조구에 비해 유의하게 일당증체량이 증가하였으며 (P<0.05) 첨가수준이 증가할수록 그 경향은 더욱 뚜렷하였다. 전체 사양 실험 기간동안 일당증체량, 일당사료섭취량 및 사료효율은 생균제 첨가구가 대조구에 비해 증가하는 경향을 보였으나 통계적으로 유의한 차이는 없었다. 생균제에 의한 영양소 소화율 및 질소 축적율을 조사하기 위해 자돈기와 육성기에 두번에 결쳐 대사실험을 실시하였다. 자돈기(평균 체중 17.93 $\pm$ 1.45kg )에서는 건물, 조단백질, 조지방의 소화율이 P-O.I 과 P-0.2 생균제 처리구에서 대조구에 비해 증가하였으며 (P<0.05), 조회분의 소화율은 P-0.2 처리구가 대조구에 비해서 유의하게 증가하였다. (P<0.05). 칼슐의 소화용은 P-0.2 처리구가 P-O.I 및 대조구에 비해 유의 하게 높았지만(P<0.05), 인의 소화율에서는 처리간 차이가 나타나지 않았다. 질소 축적율에서는 P-O.2와 P-O.1 생균제 처리구가 분내 질소 함량을 유의하게 낮추었으나( P<0.05), 뇨내 질소 함량 및 질소 축적율에는 영향을 미치지 않았다. 육성기(평균체중 41.80 $\pm$2.68kg)에서는 처리간 영양소 소화율 및 질소 축적율이 통계적으로 유의한 차이를 보이지 않았다. 그리고 혈중 요소태 질소농도 및 혈액내 액혈구, IgG, IgA의 함량도 전 기간에 걸쳐 처리간의 차이가 나타나지 않았다. 본 실험을 통하여 사료내 지속적인 생균제의 첨가는 돼지의 성장과 영양소 소화율을 향상 시킬 수 있을 것으로 사료된다.

• 전기의세계
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• 제31권6호
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• pp.445-449
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• 1982

This Paper describes the influence of additive concentrations and sintering temperature on the surge protection performance in ZnO ceramic varistors. It is found from the experiments that the metal-oxide semiconductors based oi ZnO with an additive incorporation of 0.50% molx(Bi$\_$2/O$\_$3/+MnO+CoO+Cr$\_$2/O$\_$3/+2Sb$\_$2/O$\_$3/) and sintered at 1250.deg. C present excellent V-I characteristics in view of transient surge suppression. Gapless arrester element with aluminum electrodes shows also good reliability against impulse shock and marks a low voltage clamping ratio(V$\_$1KA/V$\_$1mA/<2.0) compared with the conventional SiC varistors.

• Transactions on Electrical and Electronic Materials
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• 제6권5호
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• pp.202-209
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• 2005

Phase evolution, microstructure and the electrical properties such as $k_p$ and $Q_m$ of $Pb(Mg_{1/3}Nb_{2/3})O_3[PMN]-Pb(Mn_{1/3}Nb_{2/3})O3[PM'N]-PbZrO_3[PZ]-PbTiO_3[PT]$ quaternary system were investigated within the compositional ranges $0{\leq}y{\leq}0.125$, y+z=0.125, and $0.39{\leq}x{\leq}0.54$ of the formula $Pb_{0.97}Sr_{0.03}[Mg_{1/3}Nb_{2/3})_y\;(Mn_{1/3}Nb_{2/3})_z\;(Zr_{x}Ti_{1-x})_{1-(y+z)}]O_3$. In the case of increasing Mn/(Mg+Mn) ratio for a fixed Zr/Ti ratio of 47.5/52.5, phase relation remained unchanged but the grain size drastically decreased, and the electrical properties changed as following: both $k_P$ and $Q_m$ reached the peak values at $Mn/(Mg+Mn)\cong0.3l7$ and gradually decreased; $\varepsilon33^T$ showed a monotonic decrease; P-E hysteresis loop gradually changed to asymmetrical one, and $E_i$ increased in correspondence. With increasing Zr/Ti ratio for a fixed Mn/(Mg+Mn) ratio of 0.317, on the contrary, the cell parameter $(\alpha^2c)^{1/3}$ gradually increased, and tetragonal-rhombohedral morphotropic phase boundary appeared in the range of $51/49{\leq}Zr/Ti{\leq}54/46$. the meantime, the grain size substantially increased, and the electrical properties changed as following: $k_P$ and $\varepsilon33^T$ reached peak values at Zr/Ti=51/49 and 48/52, respectively, and then gradually decreased; change of $Q_m$ was adverse to $k_P$; both $E_C\;and\;E_i$ considerably decreased while $P_S$ moderately increased. For the system 0.125(PMN+PM'N)-0.875PZT studied, the composition Mn/(Mg+Mn)=0.3l7 and Zr/Ti=51/49 revealed some promising electrical properties for piezoelectric transformer application such as $k_P=0.58,\;Q_m\cong1000$, and $\varepsilon^T_{33}=970$, as well as dense and fine-grained microstructure.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.341.1-341.1
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• 2014

In the advanced material for the next generation display device, transparent amorphous oxide semiconductors (TAOS) are promising materials as a channel layer in thin film transistor (TFT). The TAOS have many advantages for large-area application compared with hydrogenated amorphous silicon TFT (a-Si:H) and organic semiconductor TFT. For the reasonable characteristics of TAOS, The a-IGZO has the excellent performances such as low temperature fabrication (R.T~), high mobility, visible region transparent, and reasonable on-off ratio. In this study, we investigated how the electric characteristics and physical properties are changed as various oxygen ratio when magnetron sputtering. we analysis a-IGZO film by AFM, EDS and I-V measurement. decreasing the oxygen ratio, the threshold voltage is shifted negatively and mobility is increasing. Through this correlation, we confirm the effect of oxygen ratio. We fabricated the bottom-gate a-IGZO TFTs. The gate insulator, SiO2 film was grown on heavily doped silicon wafer by thermal oxidation method. a-IGZO channel layer was deposited by RF magnetron sputtering. and the annealing condition is $350^{\circ}C$. Electrode were patterned Al deposition through a shadow mask(160/1000 um).

• 한국재료학회지
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• 제22권12호
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• pp.689-695
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• 2012

We have examined the co-doping effects of 1/2 mol% NiO and 1/4 mol% $Cr_2O_3$ (Ni:Cr = 1:1) on the reaction, microstructure, and electrical properties, such as the bulk defects and the grain boundary properties, of ZnO-$Bi_2O_3-Sb_2O_3$ (ZBS; Sb/Bi = 0.5, 1.0, and 2.0) varistors. The sintering and electrical properties of Ni,Cr-doped ZBS, ZBS(NiCr) varistors were controlled using the Sb/Bi ratio. Pyrochlore ($Zn_2Bi_3Sb_3O_{14}$), ${\alpha}$-spinel ($Zn_7Sb_2O_{12}$), and ${\delta}-Bi_2O_3$ were detected for all of compositions. For the sample with Sb/Bi = 1.0, the Pyrochlore was decomposed and promoted densification at lower temperature by Ni rather than by Cr. A homogeneous microstructure was obtained for all of the samples affected by ${\alpha}$-spinel. The varistor characteristics were not dramatically improved (non-linear coefficient, ${\alpha}$ = 5~24), and seemed to form ${Zn_i}^{{\cdot}{\cdot}}$(0.17 eV) and ${V_o}^{\cdot}$(0.33 eV) as dominant defects. From impedance and modulus spectroscopy, the grain boundaries were found to have been divided into two types, i.e., one is tentatively assigned to ZnO/$Bi_2O_3$ (Ni,Cr)/ZnO (0.98 eV) and the other is assigned to a ZnO/ZnO (~1.5 eV) homojunction.