• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.859-864
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• 2004

The solid solutions of the $Sr_{1-x}Ba_xFeO_{3-y)$ system (x = 0.0, 0.1, 0.2 and 0.3) having a perovskite structure were prepared in air at 1423 K and then heat-treated in air (A), $O_2(O)\;and\;N_2(N)$ to examine possibility of controlling the nonstoichiometry and applicability as an additive for electrical conducting inorganic adhesives (ECIA). In the samples heated in $N_2$ stream, there existed almost no $Fe^{4+}$ ions, and at constant temperature their electrical conductivities were considerably lower than those of the samples heat-treated in air or $O_2.\; Sr_{0.8}Ba_{0.2}Fe^{3+}_{0.49}Fe^{4+}_{0.51}O_{2.76}$ (SB2-A) whose $Fe^{3+}/Fe^{4+}$ ratio was nearly 1 (0.96) and whose conductivity values (1.04 $ohm^{-1}cm^{-1}$ at 283 K and 1.88 $ohm^{-1}cm^{-1}$ at 673 K) were higher than any other samples, was found to be the best additive for ECIA.

• Honam Mathematical Journal
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• v.8 no.1
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• pp.51-74
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• 1986

The thery of measure is significant in that we extend from it to the theory of integration. AS specific metric outer measures we can take Hausdorff outer measure and Lebesgue-Stieltjes outer measure connecting measure with monotone functions.([12]) The purpose of this paper is to find some properties of Lebesgue-Stieltjes measure by extending it from $R^1$ to $R^n(n{\geq}1)$ $({\S}3)$ and differentiation of the integral defined by Borel measure $({\S}4)$. If in detail, as follows. We proved that if $_n{\lambda}_{f}^{\ast}$ is Lebesgue-Stieltjes outer measure defined on a finite monotone increasing function $f:R{\rightarrow}R$ with the right continuity, then $$_n{\lambda}_{f}^{\ast}(I)=\prod_{j=1}^{n}(f(b_j)-f(a_j))$$, where $I={(x_1,...,x_n){\mid}a_j$<$x_j{\leq}b_j,\;j=1,...,n}$. (Theorem 3.6). We've reached the conclusion of an extension of Lebesgue Differentiation Theorem in the course of proving that the class of continuous function on $R^n$ with compact support is dense in $L^p(d{\mu})$ ($1{\leq$}p<$\infty$) (Proposition 2.4). That is, if f is locally $\mu$-integrable on $R^n$, then $\lim_{h\to\0}\left(\frac{1}{{\mu}(Q_x(h))}\right)\int_{Qx(h)}f\;d{\mu}=f(x)\;a.e.(\mu)$.

• Korean Journal of Crystallography
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• v.8 no.1
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• pp.59-63
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• 1997

A method for the calculation of the idealized hydrogen positions in the following seven different kinds of compounds has been shown: (1) tertiary C-H, (2) secondary C-H, (3) $CH_3$ group with tetrahedral angles, (4) aromatic C-H or amide N-H, (5) O-H group with X-O-H angle tetrahedral, (6) terminal $X=CH_2$ or $X=NH_2^+$ with the hydrogen atoms in a plane and (7) acetylenic C-H with X-C-H linear.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.9
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• pp.1296-1299
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• 2012

$YBa_2Cu_3O_{7-x}$ thin films were fabricated by the spin-coating method on $SiO_2$/Si substrate using an alkoxide-based sol-gel method. The structural and electrical properties were investigated for various 1st annealing temperature. Due to the formation of the polycrystalline single phase, synthesis temperature was observed at around $720^{\circ}C-800^{\circ}C$. $YBa_2Cu_3O_{7-x}$ thin films with the 1st annealing temperature of $450^{\circ}C{\sim}500^{\circ}C$ showed the single XRD patterns without the second phase, such as $YBa_2Cu_4O_8$. The thickness of films was approximately $0.23{\mu}m{\sim}0.27{\mu}m$. Aerage grain size, resistance and temperature coefficient of resistance (TCR) of $YBa_2Cu_3O_{7-x}$ thin films with the 1st annealing temperature of $500^{\circ}C$ were $0.27{\mu}m$, $59.7M{\Omega}$ and -3.7 %/K, respecvitely.

• Journal of Electrical Engineering and Technology
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• v.2 no.1
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• pp.98-101
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• 2007

Yttrium(Y)-substituted bismuth titanate $(Bi_{4-x},Y_x)Ti_3O_{12}$ [x=0, 0.25, 0.5, 0.75, 1](BYT) thin films were deposited using an RF sputtering method on the $Pt/TiO_2/SiO_2/Si$ substrates. The structural properties and electrical properties of yttrium-substituted $(Bi_4-xYx)Ti_3O_{12}$ thin films were analyzed. The remanent polarization of $(Bi_4-xYx)Ti_3O_{12}$ films increased with increasing Y-content. The $(Bi_{3.25}Y_{0.75})Ti_3O_{12}$ films fabricated using a top Au electrode showed saturated polarization-electric field(P-E) switching curves with a remanent polarization(Pr) of $8{\mu}C/cm^2$ and coercive field (Ec) of 53 kV/cm at an applied voltage of 7 V. The $(Bi_{3.25}Y_{0.75})Ti_3O_{12}$ films exhibited fatigue-free behavior up to $4.5{\times}10^{11}$ read/write switching cycles at a frequency of 1MHz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.171-172
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• 2007

We fabricated the metal-ferroelectric-insulator-semiconductor filed-effect transistors (MFIS-FETs) using the $(Bi,La)_4Ti_3O_{12}\;and\;LaZrO_x$ thin films. The $LaZrO_x$ thin film had a equivalent oxide thickness (EOT) value of 8.7 nm. From the capacitance-voltage (C-V) measurements for an Au/$(Bi,La)_4Ti_3O_{12}/LaZrO_x$/Si MFIS capacitor, a hysteric shift with a clockwise direction was observed and the memory window width was about 1.4 V for the bias voltage sweeping of ${\pm}9V$. From drain current-gate voltage $(I_D-V_G)$ characteristics of the fabricated Fe-FETs, the obtained threshold voltage shift (memory window) was about 1 V due to ferroelectric nature of BLT film. The drain current-drain voltage $(I_D-V_D)$ characteristics of the fabricated Fe-FETs showed typical n-channel FETs current-voltage characteristics.

• Korean Journal of Materials Research
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• v.30 no.5
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• pp.262-266
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• 2020

In this paper, we investigated the effect of the passivation stack with Al₂O₃, hydrogenated silicon nitride (SiN_x:H) stack and Al₂O₃, silicon oxynitride (SiON_x) stack in the n type bifacial solar cell on monocrystalline silicon. SiNx:H and SiON_x films were deposited by plasma enhanced chemical vapor deposition on the Al₂O₃ thin film deposited by thermal atomic layer deposition. We focus on passivation properties of the two stack structure after laser ablation process in order to improve bifaciality of the cell. Our results showed SiN_x:H with Al₂O₃ stack is 10 mV higher in implied open circuit voltage and 60 ㎲ higher in minority carrier lifetime than SiON_x with Al₂O₃ stack at Ni silicide formation temperature for 1.8% open area ratio. This can be explained by hydrogen passivation at the Al₂O₃/Si interface and Al₂O₃ layer of laser damaged area during annealing.

• Toxicological Research
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• v.33 no.4
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• pp.315-323
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• 2017

Preconceptual sex selection is still a highly debatable process whereby X- and Y-chromosome-bearing spermatozoa are isolated prior to fertilization of the oocyte. Although various separation techniques are available, none can guarantee 100% accuracy. The aim of this study was to separate X- and Y-chromosome-bearing spermatozoa using methods based on the viability difference between the X- and Y-chromosome-bearing spermatozoa. A total of 18 experimental semen samples were used, written consent was obtained from all donors and results were analysed in a blinded fashion. Spermatozoa were exposed to different pH values (5.5, 6.5, 7.5, 8.5, and 9.5), increased temperatures ($37^{\circ}C$, $41^{\circ}C$, and $45^{\circ}C$) and ROS level ($50{\mu}M$, $750{\mu}M$, and $1,000{\mu}M$). The live and dead cell separation was done through a modified swim-up technique. Changes in the sex-chromosome ratio of samples were established by double-label fluorescent in situ hybridization (FISH) before and after processing. The results indicated successful enrichment of X-chromosome-bearing spermatozoa upon incubation in acidic media, increased temperatures, and elevated $H_2O_2$. This study demonstrated the potential role for exploring the physiological differences between X-and Y-chromosome-bearing spermatozoa in the development of preconceptual gender selection.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.333-333
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• 2012

In this study, we investigated morphology of nanotube and micropore on the Ti-25Nb-xHf alloys with Hf contents after anodization. Ti-25Nb-xHf ternary alloys contained from (0~15) wt.% Hf contents were manufactured by vacuum arc-melting furnace. The obtained ingots were homogenized in an argon atmosphere at $1000^{\circ}C$ for 12h and then water quenching. The specimens were cut from ingots to 3mm thickness and first ground and polished using SiC paper (grades from 100 to 2000). 2steps anodization treatments on Ti-25Nb-xHf alloys were carried out at room temperature for experiments. Micro-pore formation was performed in Ca+P mixed solution at 265V for 3min. After that, nanotube formation was in 1M $H_3PO_4$ electrolytes containing 0.8wt.% NaF solutionat 10V for 120min. Morphologies of micropore and nanotube depended on the Hf content in Ti-25Nb-xZr ternary system.

• Journal of Magnetics
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• v.18 no.1
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• pp.5-8
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• 2013

The perpendicular magnetic anisotropy of sputtered CoFeB thin films covered by MgO was investigated by vibrating sample magnetometry. Three different $Co_xFe_{80-x}B_{20}$ alloys were studied. Under out-of plane magnetic field, the saturation field was found to increase with increasing the Co content. The magnetization and interface anisotropy energy were obtained for all samples. Both showed a marked dependence on the MgO overlayer thickness. In addition, their variations were found to be non-monotonous as a function of the Co concentration.