• 대한한방부인과학회지
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• 제19권3호
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• pp.151-173
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• 2006

Purpose : This study was performed to evaluate anti-thrombotic and anti-inflammatory effects of BokbangHongdeungPaejangSan water extract (BHPS). Methods : BHPS was investigated using cultured cells and a murine models. As for the parameters of inflammation, levels of several inflammatory cytokines and chemical mediators which are known to be related to inflammation were determined in mouse lung fibroblast cells (mLFC) and RAW 264.7 cells. Results : In experiment of anti-thrombotic effect, BHPS inhibited the platelet aggregation induced by ADP and epinephrine, and inhibited pulmonary embolism induced by collagen and epinephrine. BHPS increased Platelet number and fibrinogen amount, and shortened PT and APTT in thrombus model induced by dextran. In experiment of anti-inflammatory effect, BHPS inhibited IL-1${\beta}$, IL-6, TNF-${\alpha}$, COX-2 and NOS-II mRNA expression in a concentration-dependent manner in RAW 264.7 cell line, and inhibited significantly NO production at 50, 100 ${\mu}g/ml$, and also inhibited ROS production in a concentration-dependent manner. BHPS inhibited IL-1${\beta}$, IL-6 and TNF-${\alpha}$ production significantly in serum of acute inflammation-induced Balb/c mice, and decreased IL-1${\beta}$, IL-6 and TNF-${\alpha}$ production in spleen tissue, but increased IL-1${\beta}$, IL-6 and TNF-${\alpha}$ production in liver tissue. BHPS increased survival rate at the 3th day in ICR mice with lethal endotoxemia induced by LPS. Conclusion : These results suggest that BHPS can be used for treating diverse female diseases caused by thrombosis and inflammation such as endometriosis, pelvic pain, cervicitis, pelvic inflammatory disease and pelvic tuberculosis and so forth.

• 한국재료학회지
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• 제14권10호
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• pp.701-706
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• 2004

Bismuth layered structure ferroelectric thin films, La-substituted $Bi_{4}Ti_{3}O_{12}$ ($Bi_{1-x}La_{x}Ti_{3}O_{12}$, x=0.75, BLT) were prepared on the $Pt(111)/Ti/SiO_2/Si(100)$ substrates by a sol-gel spin coating process. The thin films were annealed in various conditions, i.e., oxygen, nitrogen and vacuum atmospheres for various annealing time. We investigated the annealing condition effects on the grain orientation and ferroelectric properties. The measured XRD patterns revealed that the BLT thin films showed only $Bi_{4}Ti_{3}O_{12}$-type phase with random orientation. $La^{3+}$ ion substitution for $Bi^{3+}$ ion in perovskite layers of $Bi_{4}Ti_{3}O_{12}$ decreased the degree of c-axis orientation and increased the remanent polarization ($2P_{r}$). The remanent polarization ($2P_{r}$) and the coercive field ($2E_{c}$) of the BLT thin film annealed at $650^{\circ}C$ for 5 min in oxygen atmosphere were $87{\mu}C/cm^2$ and 182 kV/cm, respectively, at an applied electric field of 240 kV/cm. For all of the BLT thin films annealed in various conditions, the fatigue resistance was shown. The improvement of ferroelectric properties with La substitution in $Bi_{4}Ti_{3}O_{12}$ could be attributed to the changes in space charge densities and grain orientation in the thin film.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1921-1923
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• 2001

In this work, an array of resistance temperature detector(RTD) was fabricated inside the microchannel in order to investigate in-situ flow characteristics. A rectangular straight microchannel, integrated with RTD's for temperature sensing and a heat source for generating the temperature gradient along the channel. were fabricated with the dimension of $200{\mu}m(W){\times}{\mu}m(D){\times}$48mm(L), while RTD measured precise temperatures at the inside-channel wall. 4" $525{\pm}25{\mu}m$ thick P-type <100> Si wafer was used as a substrate. For the fabrication of RTDs. 5300$\AA$ thick Pt/Ti layer was sputtered on a Pyrex glass wafer. Finally, glass wafer was bonded with Si wafer by anodic bonding, therefore RTD was located inside the microchannel. The temperature distribution inside the fabricated microchannel was obtained from 4 point probe measurements and Dl water is used as a working fluid. Temperature distribution inside the microchannel was measured as a function of mass flow rate and heat flux. As a result, precise temperatures inside the microchannel could be obtained. In conclusion, this novel temperature distribution measurement system will be very useful to the accurate analysis of the flow characteristics in the microchannel.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.960-964
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• 2004

[ $Ba_2NaNb_5O_{15}$ ](BNN) thin films have been prepared by the ion beam sputter deposition (IBSD) method on Pt coated Si substrate at temperature as low as $600^{\circ}C$ XRD, SEM were used to investigate the crystallization and microstructure of the films. It was found that the films were crack-free and uniform in microstructure. The electric properties of thin films were carried out by observation of D-E hysteresis loop, dielectric constant and leakage current. It was found the deposition rate strongly influenced the phase formation of the films, where the phase of $BaNb_2O_6$ was always formed when the deposition rate was high. However, the single phase (tungsten bronze structure ) BNN thin film was obtained with the deposition rate as low as $22{\AA}/min$. The remanent polarization Pr and dielectric constant are about 1-2 ${\mu}C/cm^2$ and $100\sim200$, respectively. It was also founded the electric properties of thin films were influenced by the deposition rate. The Pr and dielectric constant of films increased with the decrease of deposition rate. The effects of annealing temperature and annealing time to the crystallization behavior of films were studied. The crystallization of thin film started at about $600^{\circ}C$. The adequate crystallization was gotten at the temperature of $650^{\circ}C$ when the annealing time is 0.5 hour or at the temperature of $600^{\circ}C$ when the annealing time is long as 6 hours.

• 한국전기전자재료학회논문지
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• 제22권4호
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• pp.290-296
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• 2009

$Bi_{4}Ti_{3}O_{12}$ (BiT) thin films were grown on the Pt/Ti/$SiO_2$/si substrate using a metal organic decomposition (MOD) method. Effects of oxygen annealing on the structural properties and dielectric properties of the BiT thin films were investigated. The BiT films were well developed when rapid thermal annealed at $>500^{\circ}C$ in oxygen ambient. For the film annealed at $700^{\circ}C$, no crystalline phase was observed under oxygen free annealing atmosphere while its crystallinity was significantly enhanced as the oxygen pressure increased. The BiT film also exhibited a smooth surface with defect free grains. A high dielectric constant and a low dielectric loss were achieved satisfactory in the frequency range from 75 kHz to 1 MHz. Especially, the BiT film, annealed at $700^{\circ}C$ and 10 torr oxygen pressure, showed good dielectric properties: dielectric constant of 51 and dielectric loss of 0.2 % at 100 kHz. Its leakage current was also considerably improved, being as $0.62\;nA/cm^2$ at 1 V. Therefore, it is considered that the oxygen annealing has effects on an enhancement of crystallinity and dielectric properties of the BiT films.

• 한국재료학회지
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• 제20권5호
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• pp.241-245
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• 2010

One of the weak points of the Cr-doped SZO is that until now, it has only been fabricated on perovskite substrates, whereas NiO-ReRAM devices have already been deposited on Si substrates. The fabrication of RAM devices on Si substrates is important for commercialization because conventional electronics are based mainly on silicon materials. Cr-doped ReRAM will find a wide range of applications in embedded systems or conventional memory device manufacturing processes if it can be fabricated on Si substrates. For application of the commercial memory device, Cr-doped $SrZrO_3$ perovskite thin films were deposited on a $SrRuO_3$ bottom electrode/Si(100)substrate using pulsed laser deposition. XRD peaks corresponding to the (112), (004) and (132) planes of both the SZO and SRO were observed with the highest intensity along the (112) direction. The positions of the SZO grains matched those of the SRO grains. A well-controlled interface between the $SrZrO_3$:Cr perovskite and the $SrRuO_3$ bottom electrode were fabricated, so that good resistive switching behavior was observed with an on/off ratio higher than $10^2$. A pulse test showed the switching behavior of the Pt/$SrZrO_3:Cr/SrRuO^3$ device under a pulse of 10 kHz for $10^4$ cycles. The resistive switching memory devices made of the Cr-doped $SrZrO_3$ thin films deposited on Si substrates are expected to be more compatible with conventional Si-based electronics.

• 한국재료학회지
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• 제17권11호
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• pp.574-579
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• 2007

Amorphous $BaTi_4O_9$ ($BT_4$) film was deposited on Pt/Si substrate by RF magnetron sputter and their dielectric properties and electrical properties are investigated. A cross sectional SEM image and AFM image of the surface of the amorphous $BT_4$ film deposited at room temperature showed the film was grown well on the substrate. The amorphous $BT_4$ film had a large dielectric constant of 32, which is similar to that of the crystalline $BT_4$ film. The leakage current density of the $BT_4$ film was low and a Poole-Frenkel emission was suggested as the leakage current mechanism. A positive quadratic voltage coefficient of capacitance (VCC) was obtained for the $BT_4$ film with a thickness of <70 nm and it could be due to the free carrier relaxation. However, a negative quadratic VCC was obtained for the films with a thickness ${\geq}96nm$, possibly due to the dipolar relaxation. The 55 nm-thick $BT_4$ film had a high capacitance density of $5.1fF/{\mu}m^2$ with a low leakage current density of $11.6nA/cm^2$ at 2 V. Its quadratic and linear VCCs were $244ppm/V^2$ and -52 ppm/V, respectively, with a low temperature coefficient of capacitance of $961ppm/^{\circ}C$ at 100 kHz. These results confirmed the potential suitability of the amorphous $BT_4$ film for use as a high performance metal-insulator-metal (MIM) capacitor.

• Journal of Electrical Engineering and Technology
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• 제5권4호
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• pp.640-645
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• 2010

This paper describes the power generating property of hydrothermally grown ZnO nanorods on a flexible polyethersulfone (PES) substrate. The piezoelectric currents generated by the ZnO nanorods were measured when bending the ZnO nanorod by using I-AFM, and the measured piezoelectric currents ranged from 60 to 100 pA. When the PtIr coated tip bends a ZnO nanorod, piezoelectrical asymmetric potential is created on the nanorod surface. The Schottky barrier at the ZnO-metal interface accumulates elecntrons and then release very quickly generating the currents when the tip moves from tensile to compressed part of ZnO nanorod. These ZnO nanorods were grown almost vertically with the length of 300-500 nm and the diameter of 30-60 nm on the Ag/Ti/PES substrate at $90^{\circ}C$ for 6 hours by hydrothermal method. The metal-semiconductor interface property was evaluated by using a HP 4145B Semiconductor Parameter Analyzer and the piezoelectric effect of the ZnO nanorods were evaluated by using an I-AFM. From the measured I-V characteristics, it was observed that ZnO-Ag and ZnO-Au metal-semiconductor interfaces showed an ohmic and a Schottky contact characteristics, respectively. ANSYS finite element simulation was performed in order to understand the power generation mechanism of the ZnO nanorods under applied external stress theoretically.

• 전기학회논문지
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• 제63권11호
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• pp.1575-1581
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• 2014

In this paper, eddy current loss, iron loss and heat transfer of PMSG with 2,000kW capacities were analyzed for wind turbine. The PMSG with 3 split magnet was analyzed using ansoft maxwell commercial program and, generator was tested by Back to Back converter with no load condition at laboratory. Rotor surface temperature was measured by Pt100 sensors for investigating heat transfer from rotor to atmosphere. The simulation results shows 27.4kW eddy current loss in no load condition and 50.2kW eddy current loss in rated load condition with 3 split magnet, and also shows 4.3kW iron loss in no load condition and 7.3kW iron loss rated load condition. The heat transfer coefficient of convection between rotor surface and atmosphere was investigated by $9.6W/m^2{\cdot}K$. Therefore the heat transfer from rotor to atmosphere was about 17kW(54%) and from rotor to air-gap was about 14.6kW(46%) in no load condition. It is identified that the cooling system for stator have to include the 46% of iron loss, and heat dissipation structure of rotor surface have to be suggested and designed for efficiency improvement of generator.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.104-107
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• 2001

The fabricated La-modified lead titanate (PLT) thin flim without paling treatment was investigated for modulation frequency dependence of pyroelectric properties by the dynamic method. $Pb_{1-x}La_{x}Ti_{1-x/4}O_{3}$ PLT (x=0.1) thin film having 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 $6.6{\times}10^{-9}C/cm_{2}\cdot K$ without frequency dependence. The figure of merits for the voltage responsivity and specific detectivity are $1.03{\times}10^{-11}C\cdot cm/J$ and $1.46\times 10^{-9}C\cdot cm/J$, respectively. The PLT(10) thin film has voltage responsivity (Rv) of 5.15 V/W at 8 Hz. Noise equivalent power (NEP) and specific detectivity (D*) of the PLT(10) thin film are$9.93{\times}10^{-8}W/Hz^{1/2}$ and $1.81\times 10^{6}cmHz^{1/2}/W$ 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.