• Title/Summary/Keyword: hydrogenated

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The Effect of Hydrogen on the Tribological Properties of Hydrogenated Amorphous Carbon Films

  • Shin, Jong-Han;Lim, Dae-Soon
    • The Korean Journal of Ceramics
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    • v.3 no.2
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    • pp.96-100
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    • 1997
  • Hydrogenated amorphous carbon films were deposited on silicon substrates by using an RF PECVD. The hydrogen/methane ratio was varied from 50% to 88% to study the effect of hytdrogen in the film on the tribological properties. The friction and wear behaviors of the deposited films were investigated by ball-on-disk type wear tester. FT-IR spectra were used to characterize the structure of the films. Tribological properties of carbon films were correlated with their structure such as ratio of "polymer-like" stretching type and that of sp2 bonding. The result showed that the annealing caused a decrease in the amount of wear of contacted $Si_3N_4$ balls and a increase in the coefficient of friction. Possible explanation for annealing effect was discussed by the hydrogen desorption.esorption.

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Effects of Photon Energy Spectrum on the Photocurrent of Hydrogenated Amorphous Silicon Thin Film Transistor by Using Frequency Filters

  • Cho, Eou Sik;Kwon, Sang Jik
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.1
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    • pp.16-19
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    • 2013
  • Frequency filters with various filtering wavelengths were used in the photoelectric characterization of hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) and the experimental results were described and analyzed in terms of the photon energy spectral characteristics calculated from the integration of the photon energy and the spectral intensity of transmitted backlight through the filters at each wavelength. From the comparison of the photocurrents and the calculated photon energy spectrums for the filtered ranges of wavelength, it was possible to conclude that the photocurrents are closely related to the photon energy spectrums of the backlight.

Application of Low-hydrogenated Diamond-like Carbon Film to Mo-tip Field Emitter Array (낮은 수소 함유량을 갖는 유사 다이아몬드 박막의 몰리브덴 팁 전계 방출 소자 응용)

  • Ju, Byeong-Kwon;Jung, Jae-Hoon;Lee, Yun-Hi;Kim, Hoon;Oh, Myung-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.2
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    • pp.76-79
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    • 1999
  • Low-hydrogenated DLC films were coated on the Mo-tip FEAs by 'layer-by-layer' process based on the plasma-enhanced CVD method. The hydrogen content in the DLC film deposited by the 'layer-by-layer' process was appeared to be remarkably lowered through SIMS analysis. Also, the low-hydrogenated DLC-coated Mo-tip FEA showed good potentiality for FED applications in terms of turn-on voltage, emission current, emission stability and light emitting uniformity.

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Safety Evaluation of Polyethylene Glycol (PEG) Compounds for Cosmetic Use

  • Jang, Hyun-Jun;Shin, Chan Young;Kim, Kyu-Bong
    • Toxicological Research
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    • v.31 no.2
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    • pp.105-136
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    • 2015
  • Polyethylene glycols (PEGs) are products of condensed ethylene oxide and water that can have various derivatives and functions. Since many PEG types are hydrophilic, they are favorably used as penetration enhancers, especially in topical dermatological preparations. PEGs, together with their typically nonionic derivatives, are broadly utilized in cosmetic products as surfactants, emulsifiers, cleansing agents, humectants, and skin conditioners. The compounds studied in this review include PEG/PPG-17/6 copolymer, PEG-20 glyceryl triisostearate, PEG-40 hydrogenated castor oil, and PEG-60 hydrogenated castor oil. Overall, much of the data available in this review are on PEGylated oils (PEG-40 and PEG-60 hydrogenated castor oils), which were recommended as safe for use in cosmetics up to 100% concentration. Currently, PEG-20 glyceryl triisostearate and PEGylated oils are considered safe for cosmetic use according to the results of relevant studies. Additionally, PEG/PPG-17/6 copolymer should be further studied to ensure its safety as a cosmetic ingredient.

Effect of Hydrogenated Lecithin on Cytotoxicity of Liposome

  • Bae, Duck-Hwan;Shin, Jae-Sup;Jin, Fan-Long;Shin, Gwi-Su;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.339-342
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    • 2009
  • In this study, a hydrogenated lecithin-containing liposome was prepared using a sonicator and microfluidizer at high shear. The surface tension, particle size, turbidity, and transition temperature ($T_c$) of the liposome were investigated and compared with the commercially available standard surfactant Tween-60. The cytotoxicities were characterized using the MTT method. The surface tension of hydrogenated lecithin was found to be higher than that of Tween-60. The particle size prepared at above $T_c$ was smaller than that prepared below $T_c$. The results of the cytotoxicity experiment indicated that Lecinol 10 exhibits the highest I$C_{50}$ value, which shows its high safety in this study.

Fabrication of a Hydrogenated a-Si Photodiode

  • Hur, Chang-Wu
    • Journal of information and communication convergence engineering
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    • v.1 no.1
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    • pp.23-26
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    • 2003
  • A photodiode capable of obtaining a sufficient photo/dark current ratio at both a forward bias state and a reverse bias state is proposed. The photodiode includes a glass substrate, an aluminum film formed as a lower electrode over the glass substrate, an alumina film formed as a schottky barrier over the aluminum film, a hydrogenated amorphous silicon film formed as a photo conduction layer over a portion of the alumina film, and a transparent conduction film formed as an upper electrode over the hydro-generated amorphous silicon film. Growth of high quality alumina($Al_{2}O_{3}$) film using anodizing technology is proposed and analyzed by experiment. We have obtained the film with a superior characteristics

Photoconductive properties of B-doped hydrogenated amorphous silicon thin films (붕소 도핑된 수소화 비정질 실리콘박막의 광도전특성)

  • Park, Wug-Dong;Park, Ki-Chul;Park, Chang-Bae;Kim, Ki-Wan
    • Proceedings of the KIEE Conference
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    • 1987.07a
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    • pp.497-500
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    • 1987
  • Photoconductive properties of B-doped hydrogenated amorphous silicon thin films prepared by the RF glow discharge decomposition of $SiH_4-B_2H_6$ gas mixtures have been investigated. Experimental results showed that the B-doped hydrogenated amorphous silicon thin films have high photosensitivity and good optical absorption. Therefore these thin films can be used for the photoconductive layer of the vidicon target.

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Effect of Microwave Preheating and Hydrogenated Frying Fats on the Storage Stability of Yackwa (마이크로웨이브 열처리 및 경화튀김유가 약과의 저장 안정성에 미치는 영향)

  • 김창순;윤미화
    • Korean journal of food and cookery science
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    • v.15 no.3
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    • pp.264-271
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    • 1999
  • This study was conducted to know the storage stability of Yackwa, a traditional Korean fried cookie, prepared by two different cooking methods; deep fat frying at 160$^{\circ}C$ for 8 min (DFF), and preheating Yackwa dough and then deep fat frying at 180$^{\circ}C$ for 2 min (MW/DFF). Soybean oil (SBO), hydrogenated soybean oil (HSBO) or hydrogenated palm oil (HPO) were used for frying Yackwa. Compared to Yackwa prepared by DFF, all MW/DFF Yackwa samples had low fat content and high moisture content. MW/DFF saved frying time 6 min compared with DFF. Non-hydrogenated soybean oil for frying fats was replaced with hydrogenated types of soybean oil and palm oil to improve the storage stability of Yackwa. To investigate the oxidation stability of Yackwa during the accelerated storage for 15 days at 60$^{\circ}C$, acid value, anisidine value, peroxide value and oxidation value of Yackwas were measured. Acid values of Yackwa made by MW/DFF were higher than those made by DFF through the whole storage periods, regardless of frying fats. Peroxide and anisidine values of Yackwa coated with syrup were much lower than those without syrup. MW/DFF cooking method, using hydrogenated soybean oil or hydrogenated palm oil for frying, showed lowering effects on peroxide value as well as anisidine value, resulting in improved oxidation stability of Yackwa during the storage. In sensory evaluation, the acceptability of MW/DFF Yackwa was higher than those of the commerical products. Yackwa prepared by MW/DFF cooking method using hydrogenated palm oil, showed the highest acceptability in color, taste and texture among the samples.

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Type of Oil and Effect of Required HLB on Nanoemulsion Formation (오일의 종류 및 required HLB가 나노에멀젼 형성에 미치는 영향)

  • Da-yeon Lee;Hye-yun Hwang;Su-min Lim;Hy-ein Jang
    • Journal of the Korean Applied Science and Technology
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    • v.40 no.6
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    • pp.1533-1546
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    • 2023
  • Nanoemulsion is an emulsion with a particle size of about 20 ~ 200 nm and has the advantage of having a transparent or translucent appearance and improving the skin permeability of an effective material with a small particle size, so it is applied in various fields. In this study, eight oils with different types of HLB and 16 oils with different types of required HLB were selected to investigate the effect of the required HLB and the type on the formation of nanoemulsion. The surfactants used at this time were Polysorbate 60 (HLB 14.9), Sorbitan state (HLB 4.7), PEG-60 hydrogenated castor oil (HLB 14.0), which were mixed with Polysorbate 60 and Sorbitan state, fixed with HLB 14.0, and Polysorbate 60 and PEG-60 hydrogenated castor oil, respectively. The formation of nanoemulsion was different depending on the type of oil, and oil with an ester structure showed a relatively excellent nanoemulsion formation ability. In particular, it was confirmed that a stable nanoemulsion was formed without a significant change after Cetyl ethylhexanoin was produced in a small size of 40 nm or less on average. In addition, it was found that using a mixture of Polysorbate 60 and Sorbitan stearate has a superior nanoemulsion formation ability than using PEG-60 hydrogenated castor oil or Polysorbate 60 alone.