• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.251-254
• /
• 1999

In this paper V-I(Voltage to Current) converter using the series composite transistor is presented. Due to the series composite transistor employs operating in the saturation region and triode region, the proposed circuit has wide input range at low voltage. The designed V-I converter has simulated by HSPICE using 0.6${\mu}{\textrm}{m}$ n-well CMOS process with a $\pm$2.5V supply voltage. Simulation results show that the THD can be 0.81% at 4 $V_{p-p}$ differential input voltage when frequency of input signal is 10MHz.z.

• Proceedings of the KIEE Conference
• /
• 2003.07c
• /
• pp.1568-1570
• /
• 2003

We have studied the I-V characteristics of polytetrafluoroethylene(PTFE) thin film depending on a variation of thickness. Polymer PTFE buffer layer was made using thermal evaporation technique. The device was made in the structure of ITO/PTFE/Al. We have observed the NDR(negative differential resistance) behavior between 2.5V and 5V. There are some reports on this NDR behavior in the polymer thin film[1]. We have studied the NDR behavior depending on a variation thickness. As the film thickness increased, The NDR behavior decreased and moved in low electrical field, and we have studied the conduction mechanism of PTFE thin film.

• Archives of Pharmacal Research
• /
• v.11 no.2
• /
• pp.87-92
• /
• 1988

A number of substituted furodiketochroman derivatives ($lll_{a-f}$) have been synthesized by fusion of aromatic aldehydes with 5-hydroxybergapten and 5-hydroxyisopimpinellin. On the other hand, when the reaction was carried out in a solvent, the corresponding bis-furoccumarin derivatives ($lV_{c-n}$) were obtained. The anticoagulant effect of compounds $lll_{a,b,d}$ and $lv_{b,c,f,g,i,k}$ was tested. They failed to demonstrate any significant effect. The effect of the tested compounds on the arterial blood pressure was studied. Compounds $lV_c$, $lll_d$, $lll_b$, $lV_b$, $lV_k$ and $lV_i$ showed lowering effects on the normal systolic blooc pressure of anaesthetized rats in a decreasing manner.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.51 no.6
• /
• pp.229-235
• /
• 2002

This paper presents the fabrication of polycrystalline thin film transistor(TFT) using sequential lateral solidification(SLS) of amorphous silicon. The fabricated SLS TFT showed high Performance suitable for active matrix liquid crystal display(AMLCD). The SLS process involves (1) a complete melting of selected area via irradiation through a patterned mask, and (2) a precisely controlled pulse translation of the sample with respect to the mask over a distance shorter than the super lateral growth(SLG) distance so that lateral growth extended over a number of iterative steps. The SLS experiment was performed with 550$\AA$ a-Si using 308nm XeCl laser having $2\mu\textrm{m}$ width. Irradiated laser energy density is 310mJ/$\textrm{cm}^2$ and pulse duration time was 25ns. The translation distance was 0.6$\mu$m/pulse, 0.8$\mu$m/pulse respectively. As a result, a directly solidified grain was obtained. Thin film transistors (TFTs) were fabricated on the poly-Si film made by SLS process. The characteristics of fabricated SLS p -type poly-Si TFT device with 2$\mu\textrm{m}$ channel width and 2$\mu\textrm{m}$ channel length showed the mobility of 115.5$\textrm{cm}^2$/V.s, the threshold voltage of -1.78V, subthreshold slope of 0.29V/dec, $I_{off}$ current of 7$\times$10$^{-l4}$A at $V_{DS}$ =-0.1V and $I_{on}$ / $I_{off}$ ratio of 2.4$\times$10$^{7}$ at $V_{DS}$ =-0.1V. As a result, SLS TFT showed superior characteristics to conventional poly-Si TFTs with identical geometry.y.y.y.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.61 no.1
• /
• pp.57-63
• /
• 2016

Soyasaponin I, II, III and V contents were investigated in seed, cotyledons and sprouts of soybean (Glycine max (L.) Merill) subjected to germination over five days. High-performance liquid chromatography coupled with tandem mass spectrometric (HPLC-MS/MS) method was used to evaluate the content of soyasaponins. Soyasaponins contents were different according to the varieties. Germination of soybeans dramatically increased soyasaponin contents in soybean sprouts in a time-dependent manner. Cotyledons had a higher contents of soyasaponins compared to dried seed (p<0.05). After five days of germination, Soyasaponin I and II increased 10 times higher after germination. Soyasaponin I and II are major metabolites in cotyledons and hypocotyls. Soyasaponin III and V were also detected in seed and increased depended on the germination stage. Soyasaponin V was at its highest levels in the hypocotyl, almost 7 times higher than the initial content in soybean seeds. Therefore, the germination of soybean sprouts significantly increased soyasaponin content.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2003.05a
• /
• pp.53-53
• /
• 2003

Plasma polymerized organic thin films were deposited on Si(100) glass and metal substrates using thiophene and ethylcyclohexane precursors by PECVD method. In order to compare electrochemical properties of the as-grown thin films, the effects of the RF plasma power in the range of 30~100 W. AFM showed that the polymer films with smooth surface and sharp interface could be grown under various deposition conditions. Impedance analyzer was utilized for the determination of I-V curve for leakage current density and C-V for dielectric constants, respectively. To obtain C-V curve, we used a MIM structure of metal(Al)-insulator(plasma polymerized thin film)-metal(Pt) structure. Al as the electrode was evaporated on the thiophene films that grew on Pt coated silicon substrates, and the dielectric constants of the as-grown films were then calculated from C- V data measured at 1MHz. From the electrical property measurements such as I-V and C-V characteristics, the minimum dielectric constant and the best leakage current of thiophene thin films were obtained to be about 3.22 and $1{\;}{\times}10^{-11}{\;}A/cm^2$. However, in case of ethylcyclohexane thin films, the minimum dielectric constant and the best leakage current were obtained to be about 3.11 and $5{\;}{\times}10^{-12}{\;}A/cm^2$.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2007.05a
• /
• pp.142.2-142.2
• /
• 2007

• Journal of Radiation Protection and Research
• /
• v.29 no.4
• /
• pp.251-256
• /
• 2004

CsI(Tl), $CdWO_4(CWO),\;Bi_4Ge_3O_{12}(BGO)\;and\;Gd_2SiO_5:Ce(GSO)$ scintillators were studied to manufacture a phoswich detector. The maximum wavelengths of the CsI(Tl), CWO, BGO and GSO scintillators are 550 nm, 475 nm, 490 nm and 440 nm for the radioluminescence, and the absolute light outputs of the CsI(Tl), CWO, BGO and GSO scintillators are 54890 phonon/MeV, 17762 phonon/MeV, 8322 phonon/MeV and 8932 phonon/MeV with a neutral filter, and the decay time of the CsI(Tl), CWO, BGO and GSO scintillators is $1.3{\mu}s,\;8.17{\mu}s$, 213 ns and 37 ns by a single photon method. The phoswich detector which was manufactured with plastic and CsI(Tl) scintillators could separate the ${\beta}$ particle and ${\gamma}$ ray. The phoswich detector could also measure the pulse height spectra of the ${\beta}$ particle and ${\gamma}$ ray by a PSD method.

• Applied Chemistry for Engineering
• /
• v.5 no.2
• /
• pp.189-198
• /
• 1994

The adsorptive behaviors of carbon monoxide and methanol over $V_2O_5$catalyst were studied by means of thermal desorptlon spectroscopy (TDS) under ultrahigh vacuum conditions. Carbon monoxide adsorbed on oxygen-deficient V sites as well as on V=O groups of the $V_2O_5$ surface. CO adsorbed on the V sites desorbed at 380 K while CO adsorbed on the V=O groups formed carbonate species with surface oxygen of $V_2O_5$ and desorbed as $CO_2$ resulting in the reduction of the surface of she $V_2O_5$catalyst. The amount of CO adsorbed in the form of carbonate species increased by both the pre- and post-adsorbed oxygen. The adsorptive behavior of methanol over the catalyst was studied by thermal desorption experiments of $CH_3OH$, HCHO, CO, and $H_2$ upon methanol adsorption at 298 K. The results showed that methanol was adsorbed dissociatively on the $V_2O_5$catalyst as methoxy and hydroxyl groups at 298K.

• Journal of applied mathematics & informatics
• /
• v.30 no.1_2
• /
• pp.49-56
• /
• 2012

In this paper we introduce two new labelings called product antimagic labeling and total product antimagic labeling for directed graphs and show the existence of the same for Cayley digraphs of 2-generated 2-groups.