• Journal of Sensor Science and Technology
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• v.8 no.3
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• pp.226-231
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• 1999

Pyroelectric infrared sensors have been fabricated using P(VDF/TrFE) film with pyroelectric effect. The weight percent and thickness of the poled P(VDF/TrFE) film are 75/25 percent and $25\;{\mu}m$ respectively. For easier fabrication and connection method new top and bottom electrodes design was adapted for human body detecting pyroelectric infrared sensor. An aluminum infrared absorption electrode and bottom electrode were deposited by thermal evaporator. And the device was mounted in TO-5 housing to detect infrared light of $5.5{\sim}14\;{\mu}m$ wavelength. The responsibility, NEP (noise equivalent power) and specific detectivity $D^*$ of the device were $9.62{\times}10^5\;V/W$, $3.95{\times}10^{-7}\;W$ and $5.06{\times}10^5\;cm/W$ under emission energy of $13\;{\mu}W/cm^2$ respectively.

• Nutrition Research and Practice
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• v.16 no.1
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• pp.33-45
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• 2022

BACKGROUND/OBJECTIVES: Ginseng extract (GSE) and taurine (TR) are widely used antifatigue resources in functional foods. However, the mechanism underlying the antifatigue effects of GSE and TR are still unclear. Hence, we investigated whether GSE and TR have synergistic effects against fatigue in mice. MATERIALS/METHODS: L6 cells were treated with different concentrations of TR and GSE, and cell viability was determined using 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium. Oxidative stress was analyzed by immunocytochemistry using MitoTracker^TM Red FM and an anti-8-oxoguanine antibody. Respiratory gas analysis was performed to investigate metabolism. Expression of an activated protein kinase was analyzed using immunohistochemistry. Gene expression of cluster of differentiation 36 and pyruvate dehydrogenase lipoamide kinase isozyme 4 was measured using reverse transcription-polymerase chain reaction. Mice were orally administered TR, GSE, or their combination for 30 days, and then fatigue-related parameters, including lactate, blood urea nitrogen, and glycogen, were measured after forced swimming. RESULTS: TR and GSE reduced oxidative stress levels in hydrogen peroxide-stimulated L6 cells and enhanced the oxygen uptake and lipid metabolism in mice after acute exercise. After oral administration of TR or GSE for 30 days, the fatigue-related parameters did not change in mice. However, the mice administered GSE (400 mg/kg/day) alone for 30 days could swim longer than those from the other groups. Further, no synergistic effect was observed after the swimming exercise in mice treated with the TR and GSE combination for 30 days. CONCLUSIONS: Taken together, our data suggest that TR and GSE may exert antifatigue effects in mice after acute exercise by enhancing oxygen uptake and lipid oxidation.

• The Journal of the Korea Contents Association
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• v.8 no.11
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• pp.210-216
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• 2008

In this study, image comparisons were carried out using a MRI contrast medium which was derived by mixing a polyaminocarboxylic ligand and a gadolinium (III) transition metal which is paramagnetic and has good neutron absorbing capabilities with Gd-DTPA which is currently being used widely in the clinical setting. By using a 1.0T (Harmony, SIEMENS) MR equipment, phantoms of which 100cc of saline was diluted with a diethylenetriaminetriacetic acid derivative and Gd-DTPA were imaged. The amount of diethylenetriaminetriacetic acid and Gd-DTPA which was diluted into the 100cc of saline was 0.05mmol/L, 0.1mmol/L, 0.15mmol/L, 0.2mmol/L, 0.3mmol/L, 0.5mmol/L, 1.0mmol/L, 2.0mmol/L, 3.0mmol/L and 4.9mmol/L respectively. Head coils were used and while fixing the SE pulse sequence and image variable (as TE is 14ms, 1NEX with a 256x201 matrix), the signal intensity and simple contrast ratios according to changing concentrations and TR were compared with various TR at 300ms, 400ms, 500ms, 600ms, 700ms, 800ms, 900ms, 1000ms, 1200ms, 1400ms and 1600ms. According to the comparison results of the signal intensity of the image based on changes in contrast medium concentrations and TR, the differences in signal intensity between the two contrast mediums were found to be small at $1.0{\sim}2.0mmol/L$ when the highest signal intensity was achieved. However, at concentrations of 1.0mmol/L or less, the signal intensity was markedly higher in the Diethylenetriaminetriacetic acid derivative than in the Gd-DTPA complex. It was also found that the differences in the signal intensities demonstrated by the concentrations of the contrast mediums were affected by the TR. Accordingly, the efficacy of the Diethylenetriaminetriacetic acid derivative was shown to be better than the Gd-DTPA and also possible to get the optimum image quality by the use of an appropriate TR with appropriate concentrations of contrast medium.

• Progress in Medical Physics
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• v.23 no.2
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• pp.71-80
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• 2012

In order to verify exact dose distributions in the state-of-the-art radiation techniques, a newly designed three-dimensional dosimeter and technique has been took strongly into consideration. The main purpose of our study is to verify the optimized parameters of polymer gel as a real volumetric dosimeter in terms of the various study of MRI. We prepared a gel dosimeter by combing 8% of gelatin, 8% of MAA, and 10 mM of THPC. We used a Co-60 gamma-ray teletherapy unit and delivered doses of 0, 2, 4, 6, 8, 10, 12, and 14 Gy to each polymer gel with a solid phantom. We used a fast spin-echo pulse to acquire the characterized T2 time of MRI. The signal noise ratio (SNR) of the head & neck coil was a relatively lower sensitivity than the body coil; therefore the dose uncertainty of head & neck coil would be lower than body coil's. But the dose uncertainty and resolution of the head & neck coil were superior to the body coil in this study. The TR time between 1,500 ms and 2,000 ms showed no significant difference in the dose resolution, but TR of 1,500 ms showed less dose uncertainty. For the slice thickness of 2.5 mm, less dose uncertainty of TE times was at 4 Gy, as well, it was the lowest result over 4 Gy at TE of 12 ms. The dose uncertainty was not critical up to 6 Gy, but the best dose resolution was obtained at 20 ms up to 8 Gy. The dose resolution shows the lowest value was over 20 ms and was an excellent result in the number of excitation (NEX) of three. The NEX of two was the highest dose resolution. We concluded that the better result of slice thickness versus NEX was related to the NEX increment and thin slice thickness.

• 정보화사회
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• s.90
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• pp.8-15
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• 1995

최근 들어 무선통신 특히 주파수공용시스템은 산업용 이동통신서비스를 가장 효율적으로 수행할 수 있는 무선통신방식으로 각광받고 있다. 국내에서는 주파수 자원의 부족과 지속적으로 증대되는 산업용 이동통신 수요를 충족시키기 위해 TRS 의 도입과 확산이 활발해지고 있으며, 금년말로 예정되어 있는 TRS디지털 제2전국사업자 선정을 앞두고 업계의 관심이 증폭되고 있다. 이에 현재 TRS업무에 종사하고 있거나 TRS에 대해 알고자 하는 독자층을 대상으로 구체적인 기술사항을 논의하기보다는 일반적 이해의 폭을 넓히는 방향으로 서술했다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.470-473
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• 2001

In this study, 70/30 mol% P(VDF-TrFE) copolymer thin films were prepared by physical vapor deposition, and dielectric properties with frequency were investigated. From results of TA(Thermal Analysis), the Curie transition temperature and melting temperature were observed at 118.8$^{\circ}C$ and 146$^{\circ}C$, respectively. Therefore, while thin films were prepared, the substrate temperature was varied from 30$^{\circ}C$ to 90$^{\circ}C$. The dielectric constant decreased with increasing frequency. At measuring frequency of 1kHz, the relative dielectric constant increased from 3.643 to 23.998 with increasing substrate temperature from 30$^{\circ}C$ to 90$^{\circ}C$. As a result of dielectric loss factor, ${\alpha}$-relaxation and ${\beta}$-relaxation were observed near at 100Hz and 1MHz, respectively. And the magnitude of ${\alpha}$-relaxation decreased and that of ${\beta}$-relaxation increased with increasing substrate temperature.

• Journal of The Korean Astronomical Society
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• v.42 no.6
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• pp.135-144
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• 2009

We present JHK near-infrared photometric study for the old open cluster (OC) Trumpler 5 (Tr 5), based on the 2MASS data. From the color-magnitude diagrams of Tr 5, we have located the position of the red giant clump (RGC) stars, and used the mean magnitude of the RGC stars in K-band to estimate the distance to Tr 5, d = $3.1{\pm}0.1$ kpc ($(m-M)_0$ = $12.46{\pm}0.04$). From fitting the theoretical isochrones of Padova group, we have estimated the reddening, metallicity, and age : E(B-V) = $0.64{\pm}0:05$, [Fe/H] = $-0.4{\pm}0.1$ dex, and t = $2.8{\pm}0.2$ Gyr (log t = $9.45{\pm}0.04$), respectively. These parameters generally agree well with those obtained from the previous studies on Tr 5 and confirms that this cluster is an old OC with metallicity being metal-poorer than solar abundance, located in the anti-Galactic center region.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.130-131
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• 2007

In this study, polyvinylidene fluoride/trifluoroethylene (PVDF-TrFE) was investigated. For a metal-ferroelectic-metal (MFM) structure, We obtained that the 70 nm-thick film showed the maximum polarization of $8.24\;{\mu}C/cm^2$, 2Pr of $6\;{\mu}C/cm^2$ and the coercive voltage of ${\pm}3.1\;V$ at 12 V. The 140 nm-thick film showed higher performance. However, the thicker film required a higher voltage. The current density was $10^{-6}{\sim}10^{-7}\;A/cm^2$ under 15 V. We can expect from these results that the electrical properties of the devices particularly ferroelectric thin film transistor using PVDF-TrFE copolymer, be able to be on the trade-off relationship between the remanent polarization and the leakage current.

• KIEE International Transactions on Electrophysics and Applications
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• v.12C no.4
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• pp.225-228
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• 2002

The pyroelectric sensor of P(VDF/TrFE) film as sensing materials has been fabricated and evaluated with another commercial pyroelectric sensor using ceramic materials for sensing, The device was mounted in TO-5 housing to detect infrared light of a 5.5~14 ${\mu}{\textrm}{m}$ wavelength. The NEP(noise equivalent power) and specific detectivity D* of the device were 2.13$\times$10$^{-8}$ W and 9.37 10$^{6}$ cm/W under emission energy of 13 ㎼/$\textrm{cm}^2$, respectively.

• Journal of the Semiconductor & Display Technology
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• v.19 no.4
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• pp.84-87
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• 2020

The properties of ultra-thin two-dimensional (2D) organic ferroelectric Langmuir-Blodgett (LB) films of the poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] were investigated to find possible applicability in flexible and wearable electronics applications. In the C-V characteristics of the MFM capacitor of 2-monolayer of 5 nm films, a butterfly hysteresis curve due to the ferroelectricity of P(VDF-TrFE) was confirmed. Typical residual polarization value was measured at 2μC/㎠. When the MFM capacitor with ultra-thin ferroelectric film was measured by applying a 10 Hz bipolar pulse, it was shown that 65% of the initial polarization value in 105 cycles deteriorated the polarization. The leakage current density of the 2-monolayer film was maintained at about 5 × 10-8 A/㎠ for the case at a 5MV/cm electric field. The resistivity of the 2-monolayer film in the case at an electric field at 5 MV/cm was more than 2.35 × 1013 Ω·cm.