• Journal of the Korean Ceramic Society
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• v.55 no.3
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• pp.285-289
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• 2018

We synthesized silicon carbide (${\beta}-SiC$) nanowires with nano-scale diameter (30 - 400 nm) and micro-scale length ($50-200{\mu}m$) on a porous body using low-grade silica and carbon black powder by carbothermal reduction at $1300-1600^{\circ}C$. The SiC nanowires were formed by vapor-liquid-solid deposition with self-evaporated Fe catalysts in low-grade silica. We investigated the characteristics of the SiC nanowires, which were grown on a porous body with Ar flowing in a vacuum furnace. Their structural, optical, and electrical properties were analyzed with X-ray diffraction (XRD), transmission electron microscopy (TEM), and selective area electron diffraction (SAED). We obtained high-quality SiC single crystalline nanowire without stacking faults that may have uses in industrial applications.

• BMB Reports
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• v.33 no.3
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• pp.285-288
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• 2000

Ferricytochrome c was artificially made to receive the aqueous electrons evolved through the influence of illuminated chloroplast. This ferricytochrome c, which was bombarded by electrons, was reduced to ferrocytochrome c by making sure that a certain cytochrome is reduced. This may require an electronic attack that is created by the chloroplast inside the plant cell. The possibility of reversing the oxidation of ferrocytochrome c by cytochrome oxidase was examined using a contrived redox system composed of cytochrome oxidase, ferricytochrome c and chloroplast with illumination. We recognized that the oxidase is unserviceable for the reversibleness in spite of the existence of chloroplast.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.4
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• pp.285-289
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• 2011

In this study, lead-free $(K_{0.5}Na_{0.5+X})(Nb_{0.96}Sb_{0.04})O_3+0.2mol%La_2O_3+1.2mol%$ $K_4CuNb_8O_{23}$ (X= 0~0.025) ceramics were fabricated by normal sintering method at $1060^{\circ}C$ for 5 h. Microstructures, piezoelectric and dielectric properties of specimens were investigated with special emphasis in the influence of Na excess addition. The grain size of specimen was slightly decreased with increasing Na content. In the 2 [mol%] Na excess addition of NKNS ceramics, density, electromechanical coupling factor, piezoelectric constant and electromechancal quality factor of specimen were found to reach the optimum values of 4.25 [$g/cm^3$], 0.4357, 154.43 [pC/N] and 580, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.569-570
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• 2021

Hydroponic cultivation is of considerable interest to the production of high-quality green plants. However, establishing the planting operating systems in hydroponic cultivation may result in chronic problems, such as the reproduction of harmful bacteria throughout the circulating culture fluid. Extensive research has been conducted on using an ultraviolet sterilization system to prevent culture fluid contamination. In this study, the proposed module, using UV-C LEDs that emit wavelengths between 270 and 285 nm, was designed along with a sensor and controller. The module was set to emit 300, 500, and 700 mW, for different culture fluid flow rates, to investigate its capacity to eliminate Escherichia coli, Clavibacter michiganensis, Pseudomonas cichorii, and Fusarium oxysporum.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.406-408
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• 1999

Amorphous carbon nitride thin films were prepared on pretreated silicon(100) substrate in sputtering graphite target by activated gas phase using RF reactively sputtering. We measured the FT-IR spectrum to identify C=N(nitrile)stretching mode(2200cm$\^$-1/), C-H stretching mode(2800cm$\^$-1/), C-H bending mode, C=C stretching mode C=N(imino) mode(1680cm$\^$-1/ ), and the XPS to investigate chemical structure of surface. By the results of FT-H and XPS spectrum, We confirmed that amorphous carbon nitride films with typel (C(1s): 285.9[eV], N(1s): 398.5[ev]) and type 2(C1s): 287.5[eV, N(1s): 400.2[eV]) successfully were synthesized by RF reactively sputtering

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.283-285
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• 2005

Three control strategies that can be applied to a three-phase AC-DC converter under unbalanced input voltage condition are discussed. Analytic solutions are given on the a-b-c frame, and are very simple, direct and Intuitive. All of the strategies guarantee sinusoidal input currents. All the control functions, including decoupled current control and PWM, are implemented on the a-b-c frame. Accordingly, the controller is very simple and robust. The proposal is verified by simulation and experiments on a prototype operating at 15 kHz

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.285-292
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• 2017

The purpose of this study was to investigate the relationship between the fasting blood sugar and serum lipid levels (TC, TG, HDL-C, LDL-C) and obesity indices (BMI, body fat rates, waist circumference, waist to hip ratio). The study sample consists of 1,473 manufacturing workers aged from 30 to 59 years, who underwent a health check-up at a university hospital during the period from Jan. to Dec. 2015. A data analysis was conducted to classify the subjects into the normal and abnormal groups according to their fasting blood sugar levels depending on the average values of the serum lipids and obesity indices. Multiple regression analyzes adjusted for sex and age were conducted for the factors affecting the fasting blood sugar level. As a result, the Serum TC, TG, LDL-C, BMI and waist circumference were found to be significantly higher in the abnormal fasting blood sugar level group than in the normal one, but the HDL-C was significantly lower in the abnormal group than in the normal one The fasting blood sugar level had a significant positive correlation with the TC, TG, LDL-C, BMI and waist circumference. The TC, TG, BMI and body fat were the significant factors affecting the fasting blood sugar. The above results suggest that the fasting blood sugar and serum lipid levels (TC, TG, HDL-C, LDL-C), obesity indices (BMI, body fat rates, waist circumference, waist to hip ratio) of manufacturing workers are significantly associated with each other.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.204-209
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• 1993

The dried cinnamon was extracted with 12 solvents and studied the extraction conditions of temperature, time, solvent addition ratio and number of extraction for their effects on chemical and antioxidant properties of the extracts. It was found that a relatively higher antioxidant activity expressed as hydrogen donating activity was obtained from water and 70% ethanol extraction among 12 solvents investigated. The solvents of water and 70% ethanol were further studied for effects of several extraction conditions. At the temperature range of $20{\sim}100^{\circ}C\;and\;2{\sim}10$ hours of extraction, the antioxidant activity and % total phenol was significantly increased as the temperature raised up to $80^{\circ}C$ and extraction extented to 8 hours, while the solvent ratio of more than 20 times to dried cinnamon affected little. Soluble materials and degree of browning measured absorbances at 285 and 490nm were also increased at higher temperature. A significant decrease in antioxidant activity and other characteristics was measured in the extracts prepared from third times of extraction.

• Journal of Sensor Science and Technology
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• v.18 no.4
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• pp.280-285
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• 2009

In this paper, we designed a 2-stage CMOS operational amplifier with temperature compensation function using 2-poly 4-metal 0.35 $\mu$m standard CMOS technology. Using two bias circuits, the positive temperature coefficient(PTC) and the negative temperature coefficient(NTC) of the bias circuit are canceled out each other. When reference current circuit is simulated that it has a temperature coefficient of -150 ppm/$^{\circ}C$ with a temperature change from 0 $^{\circ}C$ to 120 $^{\circ}C$. Also the proposed circuit has a temperature coefficient of -0.011 dB/$^{\circ}C$ of DC open loop gain with the same temperature range.

• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.285-291
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• 2005

The nonstructural protein 5B (NS5B) of hepatitis C virus (HCV) is the viral RNA-dependent RNA polymerase (RdRp), which is the essential catalytic enzyme for the viral replication and is an appealing target for the development of new therapeutic agents against HCV infection. A small amount of serum from a single patient with hepatitis C was used to get the genome of a Korean HCV isolate. Sequence analysis of NS5B 1701 nucleotides showed the genotype of a Korean isolate to be subtype 1b. The soluble recombinant HCV NS5B polymerase lacking the C-terminal 24 amino acids was expressed and purified to homogeneity. With the highly purified NS5B protein, we established in vitro systems for RdRp activity to identify potential polymerase inhibitors. The rhodanine family compounds were found to be potent and specific inhibitors of NS5B from high throughput screening (HTS) assay utilizing the scintillation proximity assay (SPA) system. The binding mode of an inhibitor was analyzed by measuring various kinetic parameters. Lineweaver-Burk plots of the inhibitor suggested it binds not to the active site of NS5B polymerase, but to an allosteric site of the enzyme. The activity of NS5B in in vitro polymerase reactions with homopolymeric RNA requires interaction with multiple substrates that include a template/primer and ribonucleotide triphosphate. Steady-state kinetic parameter, such as Km, was determined for the ribonucleotide triphosphate. One of compounds found interacts directly with the viral polymerase and inhibits RNA synthesis in a manner noncompetitively with respect to UTP. Furthermore, we also investigated the ability of the compound to inhibit NS5B-directed viral RNA replication using the Huh7 cell-based HCV replicon system. The investigation is potentially very useful for the utility of such compounds as anti-hepatitic agents.