• 한국세라믹학회지
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• 제37권2호
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• pp.168-173
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• 2000

YMnO3 thin films were prepared on Pt/Ti/SiO2/Si substrate by chemical solution deposition method. The films were crystallized by heat-treatment at 85$0^{\circ}C$ for 1 hour. Effects of an annealing atmosphere(O2, Ar, vacuum) on the crystallization behavior and electridcal properties were investigated. YMnO3 thin films annealed under Ar atmosphere showed a superior crystallinity and a very strong c-aix preferred-orientation which was a polar axis. Leakage current density of the films decreased with lowering oxygen partial pressure of the annealing atmosphere. C-V and P-E ferroelectric hysteresis were observed only in the thin film heat-treated under Ar atmosphere.In order to prepare YMnO3 thin films having both low leakage current and ferroelectricity, the annealing atmsphere should be kept under a proper oxygen partial pressure which was about 1 Pa in this work. Leakage current density at 1 volt, dielectric constant($\varepsilon$r), remanent polarization(Pr), and coercive field(Ec) were 1.7$\times$10-8 A/$\textrm{cm}^2$, 25, 1.08$\mu$C/$\textrm{cm}^2$, and 100 kV/cm, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.463-466
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• 2001

In recent year, Ferroelectric $BLT(Bi_{4-x}La_{x}Ti_{3}O_{12})$ is a promising candidate materials. This study was practiced to make good conditions of BL T targets. In this study, calcination and sintering temperature were kept at $750^{\circ}C$, $1100^{\circ}C$ for 2 hour respectively. the density obtained 7.612, 7.98, $7.877g/cm^{3}$ as $La_{2}O_{3}$ contents were 0.0mol%, 0.25mol%, 0.5mol%. Especially, the lanthanum content of 0.5 mol% measured C-axis (117) preferred orientation more than the others targets in the XRD. In $\varepsilon_{r}-f$ relationship using by HP 4194 A impedance analyzer, the 0.5 mol% observed above 200 relative dielectric constant. but the dissipation factor was higher than others targets at 100Hz~13MHz range. SEM photograph with the content of $La_{2}O_{3}$ was observed like rod and plate types.

• 한국표면공학회지
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• 제38권2호
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• pp.60-64
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• 2005

The ICP-CVD (inductively coupled plasma chemical vapor deposition) process was applied to the deposition of $TiB_2$ films. For plasma generation, 13.56 MHz r.f. power was supplied to 2-turn Cu coil placed inside chamber. And the gas mixture of $TiCl_4,\;BCl_3,\;H_2$ and Ar was used for $TiB_2$ deposition. $TiB_2$ films with high hardness (<40 GPa) were obtained at extremely low deposition temperature $(250^{\circ}C)$, and the films hardness increased with ICP power and gas flow ratio of $TiCl_4/BCl_3$. The film structure was changed from (100) preferred orientation to random orientation with increasing RF power. It is supposed that the enhanced hardness of films was caused by a strong Ti-B chemical bonding of stoichiometric $TiB_2$ films and film densification induced by high density plasma.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.87-90
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• 2002

In recent year, BLT($Bi_{3.25}La_{0.75}Ti_{3}O_{12}$) has been one of promising substitute materials at the ferroelectric random access memory applications. We manufactured $Bi_{3.25}La_{0.75}Ti_3O_{12}$ Target with a ceramic process. The BLT target was sintered at ${1100^{\circ}C}$ for 4 hours. Using RF magnetron sputtering, a deposited BLT thin films were estimated about ferroelectric properly as a functions of post annealing temperatures. The BLT thin films showed a promoted ferroelectric characteristics at the post annealied sample of ${700^{\circ}C}$. This sample exhibited the (117) preferred crystal orientation, current density of $3{\times}10^{-8}A/cm^2$, a remanent polarization of $8{\mu}C/cm^2$ and a coercive field of 42.1 KV/cm respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.463-466
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• 2001

In recent year, Ferroelectric BLT($Bi_{4-x}$La$_{x}$Ti$_3$O$_{12}$) is a promising candidate materials. This study was Practiced to make good conditions of BLT targets. In this study, calcination and sintering temperature were kept at 75$0^{\circ}C$, 110$0^{\circ}C$ for 2 hour respectively. the density obtained 7.612, 7.98, 7.877 g/㎤ as La$_2$O$_3$ contents were 0.0mol%, 0.25mo1%, 0.5mol%. Especially, the lanthanum content of 0.5 mol% measured C-axis (117) preferred orientation more than the others targets in the XRD. In $\varepsilon$$_{r}$-f relationship using by HP 4194 A impedance analyzer, the 0.5 mol% observed above 200 relative dielectric constant. but the dissipation factor was higher than others targets at 100Hz~13MHz range. SEM photograph with the content of La$_2$O$_3$ was observed like rod and plate types.types.s.

• 한국물환경학회지
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• 제38권4호
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• pp.171-176
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• 2022

Recently, an autotrophic single-stage nitrogen removal (ASSNR) process based on the anaerobic ammonium oxidation (ANAMMOX) reaction has been proven as an economical ammonia treatment. It is highly evident that double-layered gel beads are a promising alternative to the natural biofilm for ASSNR because of the high mechanical strength of poly(vinyl alcohol) (PVA)/alginate structure and efficient protection of ANAMMOX bacteria from dissolved oxygen (DO) due to the thick outer layer. However, the thick outer layer results in severe mass transport limitation and consequent lowered bacterial activity. Therefore, the effects of the thickness of the outer layer on the overall reaction rate were tested in the biofilm model using AQUASIM for ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB) and ANAMMOX bacteria. A thickness of 0.5~1.0 mm is preferred for the maximum total nitrogen (TN) removal. In addition, a DO of 0.5 mg/L resulted in the best total nitrogen removal. A higher DO induces NOB activity and consequent lower TN removal efficiency. The optimal density of AO B and NO B density was 1~10% for a 10% ANAMMOX bacterial in the double-layered PVA/alginate gel beads. The real effects of operating parameters of the thickness of the outer layer, DO and concentrations of biomass balance should be intensively investigated in the controlled experiments in batch and continuous modes.

• 한국진공학회지
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• 제6권S1호
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• pp.75-79
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• 1997

Optical and mechanical characteristics of $TiO-2, ZrO_2 \;and\; SiO_xN_y$ thin films prepared by ion assisted deposition (IAD) were investigated. IAD films were bombarded by Ar or nitrogen ion beam from a Kaufman ion source while they were grown in as e-beam evaporator. The result shows that the Ae IAD increases the refractive index and packing density of $TiO_2 films close to those of the bulk. For $ZrO_2$ films the Ar IAD increases the average refractive index decreases the negative inhomogeneity of refractive index and reverses to the positive inhomogeneity. The optical properties result from improved packing density and denser outer layer next to air The Ar-ion bombardment also induces the changes in microstructure of $ZrO_2$ films such as the preferred (111) orientation of cubic phase increase in compressive stress and reduction of surface roughness. Inhomogeneous refractive index SiOxNy films were also prepared by nitrogen IAD and variable refractive index of $SiO_xN_y$ film was applied to fabricate a rugate filter.

• 한국분말재료학회지
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• 제30권5호
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• pp.436-441
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• 2023

Molybdenum-tungsten (Mo-W) alloy sputtering targets are widely utilized in fields like electronics, nanotechnology, sensors, and as gate electrodes for TFT-LCDs, owing to their superior properties such as high-temperature stability, low thermal expansion coefficient, electrical conductivity, and corrosion resistance. To achieve optimal performance in application, these targets' purity, relative density, and grain size of these targets must becarefully controlled. We utilized nanopowders, prepared via the Pechini method, to obtain uniform and fine powders, then carried out spark plasma sintering (SPS) to densify these powders. Our studies revealed that the sintered compacts made from these nanopowders exhibited outstanding features, such as a high relative density of more than 99%, consistent grain size of 3.43 ㎛, and shape, absence of preferred orientation.

• Clinical Nutrition Research
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• 제13권1호
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• pp.74-87
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• 2024

Since the effects of cinnamon supplementation on lipid profiles are still controversial, this study conducted a meta-analysis of randomized controlled trials to assess the effect of cinnamon supplementation on lipid profiles. The study was designed and conducted according to the guidelines of the 2020 preferred reporting items for systematic reviews and meta-analysis (PRISMA) statements. A systematic and comprehensive search was performed in several databases from inception up to 11 November 2023. The meta-analysis on the impact of Cinnamon on lipid profiles indicates a non-significant overall effect on low-density lipoprotein (weighted mean differences [WMD], -2.48; 95% confidence interval [CI], -9.70, 4.72). However, significant reductions are seen with doses < 500 mg/day (-10.26), and non-significant increases with doses ≥ 500 mg/day (1.18). The overall effect on high-density lipoprotein is non-significant (WMD, 3.97; 95% CI, -7.877, 15.831), showing varying responses at different doses. Triglycerides exhibit a significant overall reduction (WMD, -6.88; 95% CI, -12.62, -1.15), particularly in the < 500 mg/day group. The overall effect on cholesterol is non-significant (WMD, -4.314; 95% CI, -15.011, 6.384), with diverse responses at different doses. High heterogeneity underlines the importance of standardized study designs and further exploration of dosage-specific effects. Findings from this study suggest that cinnamon supplements might be beneficial to modulate the blood lipid profile.

• 전기화학회지
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• 제16권1호
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• pp.19-29
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• 2013

피로인산구리용액에서 전기도금공정을 이용하여 상온과 $55^{\circ}C$에서 각각 제조된 Cu박막의 특성에 미치는 전류밀도, 도금용액 온도, pH의 영향에 대한 연구를 수행하였다. 전류효율은 전류밀도가 증가함에 따라 감소하였으나, 도금용액의 온도가 증가함에 따라 증가하는 경향을 나타내었다. 그러나 pH 는 전류효율에 거의 영향을 미치지는 않았으며, 상온과 $55^{\circ}C$에서 모두 90% 이상으로 측정되었다. 상온에서 전기도금 된 Cu 박막의 잔류응력은 전류밀도의 증가에 따라 감소하며, 60 $mA/cm^2$ 이상에서는 거의 0에 근접하였다. $55^{\circ}C$에서 전기도금 된 Cu 박막은 0~40 MPa의 잔류응력을 나타내었다. 상온에서 도금하는 경우 수지상 표면 형상이 30 $mA/cm^2$ 이상의 전류밀도로부터 관찰되었고, $55^{\circ}C$에서는 100 $mA/cm^2$ 이상의 전류밀도부터 관찰되었다. 상온과 $55^{\circ}C$의 도금용액으로부터 전기도금 된 Cu 박막은 거의 (111) 피크들로 구성되어 있다. 특히 $55^{\circ}C$, 30 $mA/cm^2$에서 전기도금 된 Cu 박막의 경우 (111) 피크의 강한 우선방향을 나타내었다.