• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.368-368
• /
• 2012

We report solution-processed, high-performance single-crystal organic nanowire transistors fabricated from a novel indolocarbazole (IC) derivative. The direct printing process was utilized to generate single-crystal organic nanowire arrays enabling the simultaneous synthesis, alignment and patterning of nanowires using molecular ink solutions. Using this method, single-crystal organic nanowires can easily be synthesized by self-assembly and crystallization of organic molecules within the nanoscale channels of molds, and these nanowires can then be directly transferred to specific positions on substrates to generate nanowire arrays by a direct printing process. These new molecules are particularly suitable for p-channel organic field-effect transistors (OFETs) because of the high level of crystallinity usually found in IC derivatives. Selected area diffraction (SAED) and X-ray diffraction (XRD) experiments on these solution-processed nanowires showed high crystallinity. Transistors fabricated with these nanowires gave a hole mobility as high as 1.0 cm2V-1s-1 with nanowire arrays with the direct printing process.

• Natural Product Sciences
• /
• v.12 no.4
• /
• pp.221-225
• /
• 2006

Phytochemical examination of the fruits of Actinidia arguta has led to the isolation three organic acids, one coumarin, and three flavonoids. Structures of these compounds were elucidated as protocatechuic acid (1), caffeic acid (2), $caffeoyl-\beta-D-glucopyranoside$ (3), esculetin (4), quercetin (5), quercetin $3-O-\beta-D-galactopyranoside$ (6), and quercetin $3-O-\alpha-L-rhamnopyranosyl$ $(1\rightarrow6)-O-\beta-D-glucopyranoside$ (7) by comparisons with previously reported spectral data. To investigate the anti-inflammatory and anti-oxidative effects of these compounds, nitric oxide production inhibitory activity in LPS-stimulated RAW 264.7 cells and DPPH radical scavenging activities were examined. Nitric oxide productions were reduced significantly by the addition of compounds $[1(IC_{50}=59.27{\mu}g/ml),\;2(IC_{50}=27.95{\mu}g/ml),\;3(IC_{50}=73.09{\mu}g/ml),\;4(IC_{50}=67.44{\mu}g/ml),\;5(IC_{50}=17.40{\mu}g/ml),\;6(IC_{50}=41.99{\mu}g/ml),\;7(IC_{50}=54.46{\mu}g/ml)]$, and extracts $(IC_{50}=56.21{\mu}g/ml)$ compared with positive control, L-NMMA $(IC_{50}=14.48{\mu}g/ml)$. The phenolic compounds also showed anti-oxidative activities. Especially, Compounds $1(IC_{50}=8.87{\mu}g/ml),\;4(IC_{50}=3.41{\mu}g/ml),\;and\;5(IC_{50}=6.06{\mu}g/ml),\;$, showed potent anti-oxidative activities similar to L-ascorbic acid $(IC_{50}=5.89{\mu}g/ml)$.

• Natural Product Sciences
• /
• v.15 no.1
• /
• pp.27-31
• /
• 2009

The present study was performed to investigate the binding affinity of the ethanol extract from the leaves of Morus alba (EMA) and some EMA related plant materials (EMA-D, EMA-DM) for melanin-concentrating hormone-1 receptor (MCH-1) and also to examine the antagonistic effect of them for the recombinant MCH-1 receptor expressed in CHO cells. EMA, dichloromethane fraction (EMA-D) and EMA-DM exhibited high affinity for mammalian MCH receptor in receptor binding assays ($IC_{50}$ value: 2.3, 1.6 and $1.0{\mu}g/ml$, respectively). Other plant materials (MMA-D, MMA-DM) obtained from methanol extracts from the leaves of Morus alba (MMA) also exhibited high affinity for mammalian MCH receptor, even though the $IC_{50}$ values of them were lower than those of EMA-D and EMA-DM. In Chinese hamster ovary (CHO) cells expressing human MCH-1, EMA-DM and EMA-D significantly inhibited MCH-induced intracellular $Ca^{2+}$ increase ($IC_{50}$ values: 16.5 and $22.7{\mu}g/ml$, respectively). These results clearly indicate that the ethanol extract from the leaves of Morus alba (EMA) and some EMA related plant materials (EMA-D, EMA-DM) are novel selective MCH-1 receptor antagonist, respectively.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.6 s.360
• /
• pp.83-88
• /
• 2007

In this paper, we propose the function verification method of the OLED(Organic Light Emitting Diode) drive IC using PLI verification method. This method uses the HDL(Hardware Description Language) simulator, PLI(Programing Language Interface), and GUI (Graphic User Interface) image viewer. This method improves the execute efficiency 40 times than conventional function verification methods. The proposed method can be used efficiently for function verification of DDI(display driver IC) design step.

• Journal of Environmental Impact Assessment
• /
• v.32 no.5
• /
• pp.353-362
• /
• 2023

TOC, which can measure more than 90% of organic substances, can be measured quickly and easily,replacing BOD and COD, which were indicators of organic pollutants. According to water quality pollution control standards, when measuring TOC, if the inorganic carbon ratio in the sample is over 50%, the NPOC (Non-Purgeable Organic Carbon) method should be used. If volatile organic compounds (VOCs) are present at a certain concentration, the TC-IC (subtracting inorganic carbon from total carbon) method should be used. To validate the limitations of these analytical conditions, experiments were conducted by varying the ratio of TOC to IC in purified water and measuring the concentration of TOC in test solutions. The results showed no significant difference between the TC-IC method and the NPOC method. When measuring samples with added VOC standard solutions, it was observed that the carbon loss due to purging was not significant when using the NPOC method. Therefore, it is concluded that the choice of analytical method does not lead to significant differences when VOCs are present in the sample. To account for potential variations in results based on water quality pollution control standards and regulations regarding the approval and testing of environmental measurement devices, a comparison of field sample concentration values was made using two widely used types of TOC analyzers in Korea. The results showed variations of 0.02 to 0.83 mg/L between methods depending on the manufacturer, highlighting the need for caution when selecting an instrument.

• Natural Product Sciences
• /
• v.29 no.1
• /
• pp.38-41
• /
• 2023

Two xanthones and 4-phenylcoumarins were isolated from the twigs of Mesua beccariana (Baill.) Kosterm. Among them, one new xanthone, beccarianin A (1), along with 7-isoprenyl-jacareubin (2), mammea A/AA cyclo F (3), and mammea A/BA cyclo F (4). These structures were determined by spectrometric and spectroscopic methods, HRESIMS data, NMR, and UV spectra. Two xanthones (1-2) and two 4-phenylcoumarins (3-4) were evaluated for their cytotoxic effect on the HeLa cells. Compound 1 showed active activity (IC₅₀ = 8.2 µM), and compounds 3-4 showed moderate activity (IC₅₀ = 12.3 and 15.6 µM, respectively).

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.11
• /
• pp.9-14
• /
• 2007

In this article, the organic integrated circuits such as inverter, ring oscillator, NAND and NOR gates, and rectifier have been fabricated on PEN substrate by using pentacene TFTs, The OTFTs used bottom contact structure and produced the average mobility of 0.26 $cm^2/V.sec$ and on/off current ratio of $10^5$. All circuits successfully worked as the simulation results. Especially, the rectifier was able to operate up to 1 MHz input AC signals, and ring oscillator exhibited oscillation frequency of 1MHz at 40 V. Based on the results of organic integrated circuits we could confirm the possibility of the low cost RFID tags and flexible display with OTFTs.

• Journal of the Mineralogical Society of Korea
• /
• v.18 no.2
• /
• pp.117-125
• /
• 2005

It is common to find lots of organic and inorganic precipitates inside of industrial cooling system. Analytical instruments including ICP-AES, IC, XRD, and SEM were used to investigate the effects of application of Mg on reaction among coolant, precipitates and suspended matters within chiller system. Magnesium (Mg) has a decreasing effect on total dissolved material in the coolant suggesting a significant improvement of quality of coolant. Disappearance of most organic materials in the cooling devices also suggests an inhibitive effect on the growth of organic matters.

• Proceedings of the IEEK Conference
• /
• 2002.06b
• /
• pp.293-296
• /
• 2002

This paper proposes new driving methods for designing a driver independent of the current property of organic light emitting diodes (OLED) displays. The proposed methods are the Look-Up Table (LUT) and the Pulse Width Modulation (PWM). The LUT is used to handle the amount of the current for driving the OLED display panel and the PWM is applied to represent the gray scale on the OLED display panel. Segment and common drivers were implemented using delay circuits to prevent short-circuit current and a DC-DC converter was designed to supply the drivers with a power source. In particular, tile proposed methods are used for the manufacturing of 1.8" 128$\times$128 dot passive matrix OLED display panel. The designed circuit was fabricated using 0.6w, 2-poly, 3-metal, CMOS process and applied to the Personal Communication System (PCS) phone successfully.ully.

• Polymer(Korea)
• /
• v.36 no.4
• /
• pp.494-499
• /
• 2012

In this work, the effect of multi-walled carbon nanotube (MWCNT) on electromagnetic interference shielding effectiveness (EMI SE) and mechanical properties of MWCNT-reinforced polypropylene (PP) nanocomposites were investigated with varying MWCNT content from 1 to 10 wt%. Electric resistance was tested using a 4-point-probe electric resistivity tester. The EMI SE of the nanocomposites was evaluated by means of the reflection and adsorption methods. The mechanical properties of the nanocomposites were studied through the critical stress intensity factor ($K_{IC}$) measurement. The morphologies were observed by scanning electron microscopy (SEM). From the results, it was found that the EMI SE was enhanced with increasing MWCNT content, which played a key factor to determine the EMI SE. The $K_{IC}$ value was increased with increasing MWCNT content, whereas the value decreased above 5 wt% MWCNT content. This was probably considered that the MWCNT entangled with each other in PP due to an excess of MWCNT.