• The Korean Journal of Community Living Science
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• v.16 no.2
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• pp.11-16
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• 2005

The purpose of this study was to investigate the antioxidant properties of unripened apple extracts. The amount of total flavonoids in the peel and 5/30 samples were 2.7times and 5.0 times higher than the flesh and 6/30 samples, respectively. The degree of angintensin I converting enzyme (ACE) inhibition activity in hot water extracts was higher than the other extracts. In the 5/30 sample, a $0.1\%$ concentration of unripened apple powder showed almost the same electron-donating ability with a $0.5\%$ concentration of the 6/30 sample. More than $90\%$ of the electron-donating ability was observed from the peel extracts regardless of solvents used for extraction. The nitrite-scavenging effects of acetone and methanol extracts of the 5/30 sample were the strongest at pH 1.2, and especially the $80\%$ methanol extracts exhibited a powerful scavenging effect of more than $90\%$ at pH 3.0.

• Metals and materials international
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• v.24 no.6
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• pp.1333-1345
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• 2018

The effect of manganese sulfide (MnS) inclusions on the machinability of free-cutting steel is based on their morphology, size and distribution. Furthermore, the plasticity of MnS is high during the hot working caused different characterization of MnS. In this study, the deformation behavior of MnS in 1215MS steel after a thermomechanical process was investigated at 1323 K. The microstructures of MnS inclusions were characterized by optical microscopy, scanning electron microscopy, energy-dispersive spectrometry, and electron backscattering diffraction (EBSD). As the thickness reduction of the inclusions increased from 10 to 70%, their average aspect ratio increased from 1.20 to 2.39. In addition, the deformability of MnS inclusions was lower than that of the matrix. The possible slip systems of A, B, C, and D plane traces were (${\bar{1}}0{\bar{1}}$)[${\bar{1}}01$], ($10{\bar{1}}$)[101], (011)[$01{\bar{1}}$], and (110)[$1{\bar{1}}0$]. Furthermore, the EBSD measurements suggested that slip planes in MnS inclusions occur on {110} planes.

• Proceedings of the Korean Vacuum Society Conference
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• 2009.08a
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• pp.148-148
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• 2009

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.879-882
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• 1999

The effects of the substrate bias on the performance of programming erasing in p-channel flash memory cell have been investigated. It is found that applying positive substrate bias can improve the programming and erasing speed. This improvements can be explained by Substrate Current Induced Hot Electron Injection. From the results, we can confirm that BTB programming method is better in programming and erasing speed than CHE programming method.

• Publications of The Korean Astronomical Society
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• v.8 no.1
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• pp.265-272
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• 1993

Recent X-ray observations of the accretion disks in stellar black hole candidates have revealed rather complex behavior, which cannot be fully described by the simple picture of the standard disk model. In this paper, therefore, we discuss the effects of e+e- pair creation on the structure and the stability of hot accretion disks, aiming at the thorough understanding of emission properties of X-ray binaries containing black holes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.894-897
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• 2006

Spatial distribution of injected electrons and holes is evaluated by using single-junction charge pumping technique in SONOS(Poly-silicon/Oxide/Nitride/Oxide/Silicon) memory cells. Injected electron are limited to length of ONO(Oxide/Nitride/oxide) region in locally ONO stacked cell, while are spread widely along with channel in fully ONO stacked cell. Hot-holes are trapped into the oxide as well as the ONO stack in locally ONO stacked cell.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.561-566
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• 2005

Polycrystalline silicon films were deposited using hot wire CVD (HWCVD). The deposition of silicon thin films was approached by the theory of charged clusters (TCC). The TCC states that thin films grow by self-assembly of charged clusters or nanoparticles that have nucleated in the gas phase during the normal thin film process. Negatively charged clusters of a few nanometer in size were captured on a transmission electron microscopy (TEM) grid and observed by TEM. The negatively charged clusters are believed to have been generated by ion-induced nucleation on negative ions, which are produced by negative surface ionization on a tungsten hot wire. The electric current on the substrate carried by the negatively charged clusters during deposition was measured to be approximately $-2{\mu}A/cm^2$. Silicon thin films were deposited at different $SiH_4$ and $H_2$ gas mixtures and filament temperatures. The crystalline volume fraction, grain size and the growth rate of the films were measured by Raman spectroscopy, X-ray diffraction and scanning electron microscopy. The deposit ion behavior of the si1icon thin films was related to properties of the charged clusters, which were in turn controlled by the process conditions. In order to verify the effect of the charged clusters on the growth behavior, three different electric biases of -200 V, 0 V and +25 V were applied to the substrate during the process, The deposition rate at an applied bias of +25 V was greater than that at 0 V and -200 V, which means that the si1icon film deposition was the result of the deposit ion of charged clusters generated in the gas phase. The working pressures had a large effect on the growth rate dependency on the bias appled to the substrate, which indicates that pressure affects the charging ratio of neutral to negatively charged clusters. These results suggest that polycrystalline silicon thin films with high crystalline volume fraction and large grain size can be produced by control1ing the behavior of the charged clusters generated in the gas phase of a normal HWCVD reactor.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.978-984
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• 1995

This study was conducted to investigate the physiological functionality of the hot water and 70% acetone extracts obtained from the pine needle and mugwort. Flavanol tannin content was above 60% of the total polyphenol in pine needle extracts. 70% Acetone extract from pine needle exhibited inhibition percentage of about 82.2% on the mutagenicity of Trp-P-1. Angiotensin I converting enzyme(ACE) inhibition activity was 61% and 50% in the hot water extract and in the 70% acetone extract respectively. Electron donating ability(EDA) of the hot water and 70% acetone extracts obtained from the pine needle was significantly good above 80%. 70% Acetone extract from pine needle showed inhibitary effect against the polyphenol oxidase(PPO) of water dropwort. The nitrite scavenging ability was appeared in all the extracts examined and it showed $80{\sim}90%$ at pH 3.0. The oxidative stability was determined by POV. Results showed that ethyl acetate fraction is better antioxidants than chloroform and butanol fractions in the soybean oil. Then, in the mugwort extracts, antimutagenicity of 70% acetone extract was similar to that of pine needle. Ratio of ACE inhibition activity was higher than that of pine needle extracts. EDA of hot water and 70% acetone extracts was 45%. Extracts from the mugwort were lower in nitrite scavenging ability about $20{\sim}30%$ than extracts from pine needle.

• Journal of the Korean Magnetics Society
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• v.24 no.2
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• pp.51-55
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• 2014

The $Fe_3O_4$ nanoparticle was synthesized by the hot-injection method while varying the injection time of the precursor solution. The crystal structure was determined to be cubic inverse spinel with space group of Fd-3m based on X-ray diffraction (XRD) measurements and the morphology of the prepared $Fe_3O_4$ nanoparticle was studied with a high-resolution transmission electron microscope (HR-TEM). When the precursor solution was injected for 0.5 min, the size of the $Fe_3O_4$ nanoparticle was 7.63 nm, while the size of the obtained particle was 21.27 nm with the injection time of 60 min. The magnetic properties of the prepared $Fe_3O_4$ nanoparticle were investigated by both vibrating sample magnetometer (VSM) and $^{57}Co$ M$\ddot{o}$ssbauer spectroscopy at various temperatures. From the hyperthermia measurement, we observed that the temperature of the $Fe_3O_4$ nanoparticle powder reached around $120^{\circ}C$ under 250 Oe at 50 kHz, when the injection time of the precursor solution was 60 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.4
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• pp.496-501
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• 2009

This study was carried out to investigate physiological functionalities of tea prepared by various thermal processing methods from Ixeris dentata root in order to elevate utilization of Ixeris dentata root as food. These methods included natural drying (ND), hot-air drying (HAD, $75^{\circ}C$), hot-air drying after steam (HADS, steaming at $95^{\circ}C$ for 30 min) and roasting after hot-air drying (RHAD, roasting at $140^{\circ}C$ for $2{\sim}3$ min). Physiological functionalities of tea prepared by ND, HAD, HADS, and RHAD were measured as hot-water extracts and each tea was extracted by 100 mL water on 1 g dried Ixeris dentata root powder. Electron donating abilities were the highest in HADS treatment at 98%. SOD-like activities were the highest in RHAD at 35.61%. Both ACE and tyrosinase inhibitory activities were the highest on ND treatment at 52.34% and 44.60%, respectively. Nitrite scavenging abilities of all treatment were the highest at pH 1.2 and the highest activity among them was on RHAD treatment at 50.5%.