• Title/Summary/Keyword: Ar/N_2\

Search Result 963, Processing Time 0.035 seconds

The Permeation Characteristics of $O_{2}/N_{2}$ Gas for Composite Membrane Prepared by Plasma Polymerization (플라즈마 종합에 의해 제조된 복합막에 대한 $O_{2}/N_{2}$의 기체투과 특성)

  • 현상원;정일현
    • Journal of environmental and Sanitary engineering
    • /
    • v.13 no.2
    • /
    • pp.147-155
    • /
    • 1998
  • In this study, we prepared non-porous plasma membrane for having high permeability and selectivity and this membrane was deposited on the $Al_{2}O_{3}$ membrane by using $CHF_{3}$ & $SiH_{4}$ monomer. Also, we investigated for the permeation characteristics of the plasma polymer membrane by Ar plasma treatment. When the position of substrate was near cathode, the selectivity was increased with Ar plasma treatment time and rf-power. The pore size of $Al_{2}O_{3}$ membrane had an effect on the permeability and the position of substrate affected selectivity.

  • PDF

Dry Etching Characteristics of ZnO Thin Films for the Optoelectronic Device by Using Inductively Coupled Plasma

  • Joo, Young-Hee;Woo, Jong-Chang;Kim, Chang-Il
    • Transactions on Electrical and Electronic Materials
    • /
    • v.13 no.1
    • /
    • pp.6-9
    • /
    • 2012
  • In this study, we carried out an investigation of the etching characteristics (etch rate, selectivity to $SiO_2$) of ZnO thin films in $N_2/Cl_2$/Ar inductivity coupled plasma. A maximum etch rate and selectivity of 108.8 nm/min and, 3.21, respectively, was obtained for ZnO thin film at a $N_2/Cl_2$/Ar gas mixing ratio of 15:16:4 sccm. The plasmas were characterized by optical emission spectroscopy. The x-ray photoelectron spectroscopy analysis showed the efficient destruction of oxide bonds by ion bombardment. An accumulation of low volatile reaction products on the etched surface was also shown. Based on this data, an ion-assisted chemical reaction is proposed as the main etch mechanism for plasmas containing $Cl_2$.

Aldose Reductase Inhibition by Luteolin Derivatives from Parasenecio pseudotaimingasa

  • Kim, Hye-Min;Lee, Jeong-Min;Lee, Ki-Ho;Ahn, Young-Hee;Lee, Sang-Hyun
    • Natural Product Sciences
    • /
    • v.17 no.4
    • /
    • pp.367-371
    • /
    • 2011
  • Effects of the extract and fractions from Parasenecio pseudotaimingasa on rat lens aldose reductase (AR) inhibition have been investigated. Among them, the n-BuOH fraction was exhibited good inhibitory potencies ($IC_{50}$ value 1.42 ${\mu}g/ml$). Phytochemical constituents were isolated from the n-BuOH fraction by open column chromatography. Their structures were elucidated as luteolin-7-O-rutinoside (1) and luteolin-7-Oglucoside (2) on the basis of spectroscopic analysis. Compounds 1 and 2 exhibited strong AR inhibitory activity, with $IC_{50}$ values of 2.37 and 1.05 ${\mu}M$, respectively. This is the first report on the isolation of compounds 1 and 2 from P. pseudotaimingasa. These results suggest that P. pseudotaimingasa could be a useful material in the development of a novel AR inhibitory agent against diabetic complications.

Ionization and Attachment Coefficients in Mixtures of $SF_6$ and Ar ($SF_6$-Ar 혼합기체에서의 전리와부착계수)

  • 김상남;하성철
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.14 no.9
    • /
    • pp.773-778
    • /
    • 2001
  • In this dissertation the results of the combined experimental and theoretical studies designed to understand and predict the spatial growth and transport coefficients for electrons in SF$_{6}$ and SF$_{6}$-Ar mixtures have described. The ionization and attachment coefficients in pure SF$_{6}$ and SF$_{6}$-Ar mixtures have been calculated over the range of 10$_{6}$ molecule and for Ar atom proposed by other authors. The transport coefficients for electrons in (0.2%)SF$_{6}$-Ar and (0.5%)SF$_{6}$-Ar mixtures were measured by time-of-flight method, and the electron energy distribution function and the parameters of the velocity and the diffusion were determined by the variation of the collision cross-sections with energy. The results obtained in this work will provide valuable information on the fundamental haviors of electrons in weakly ionized gases and the role of electron attachment in the choice of better gases and unitary gas dielectrics or electro negative components in dielectric gas mixtures. gas mixtures.

  • PDF

The Global Publication Output in Augmented Reality Research: A Scientometric Assessment for 1992-2019

  • Gupta, B.M.;Dhawan, S.M.
    • International Journal of Knowledge Content Development & Technology
    • /
    • v.10 no.2
    • /
    • pp.51-69
    • /
    • 2020
  • This paper describes global research in the field of augmented reality (22078) as indexed in Scopus database during 1992-2019, using a series of bibliometric indicators. The augmented reality (AR) research registered high 54.23% growth, averaged citation impact of 8.90 citations per paper. Nearly 1% of global output in the subject (226 papers) registered high-end citations (100+) per paper. The top 15 countries accounted for 87.05% of global publications output in the subject. The USA is in leadership position for its highest publications productivity (19.25% global share). The U.K. leads the world on relative citation index (2.05). International collaboration has been a major driver of AR research pursuits; between 11.89% and 44.04% of national share of top 15 countries in AR research appeared as international collaborative publications. AR research productivity by application types was the largest across sectors, such as education, industry and medical. Computer science has emerged as the most popular areas in AR research pursuits. Technical University of Munich, Germany and Osaka University, Japan have been the most productive organizations and Nara Institute of S&T, Japan (66.55 and 7.48) and Imperial College, London, U.K. (57.14 and 6.42) have been the most impactful organizations. M. Billinghurst and N. Navab have been the most productive authors and S. Feiner and B. MacIntyre have been the most impactful authors. IEEE Transactions on Visualization & Computer Graphics, Multimedia Tools & Applications and Virtual Reality topped the list of most productive journals.

Effects of various Pretreatments on the Nucleation of CVD Tungsten (전처리가 CVD 텅스텐의 핵 생성에 미치는 영향)

  • Kim, Eui-Song;Lee, Chong-Mu;Lee, Jong-Gil
    • Korean Journal of Materials Research
    • /
    • v.2 no.6
    • /
    • pp.443-451
    • /
    • 1992
  • Effects of various pretreatments on the nucleation of CVD-W deposited on the reactively sputter-deposited TiN was investigated. Incubation period of nucleation and deposition rate decreased by the pretreatment of Ar rf-sputter etching for the depth below 300k, but they increased for the etchig depth over 200A. The preteatment of Ar ion implantation decreased the incubation period of nucleation, but increased deposition rate. Also Si$H_4$flushing pretreatment decreased the incubation period of nucleation slightly due to the absorption of Si by TiN surface.

  • PDF

Continuous and Pulsed Laser Induced Copper Deposition on Silicon(Si) from Liquid Electrolyte (전해질 용액내의 실리콘 단결정 표면에서 레이저로 유기되는 구리 침착)

  • 유지영;안창남;이상수
    • Korean Journal of Optics and Photonics
    • /
    • v.3 no.1
    • /
    • pp.50-54
    • /
    • 1992
  • Maskless depositon of copper onto n-doped and p-doped Si in an aqueous copper sulfate solution is investigated. On p-doped Si substrates, microscopic $(~10\mu\textrm{m}$) copper spots are deposited by illuminating continuous wave $Ar^+$ laser beam of wavelength 514.5 nm. Copper deposition on n-doped Si substrates is also achieved by shinning second harmonic pulses $(pulse width~25 nsec, \lambda=530 nm)$ of a passively Q-switched Nd:YAG laser. The observed deposition is attributed to the electric field resulting from the Galvanic potential of a semiconductor-electrolyte junction.

  • PDF

Relationship between maximum bite force and facial skeletal pattern (최대 교합력과 안면 골격 형태에 관한 연구)

  • Choi, Won-Cheul;Kim, Tae-Woo
    • The korean journal of orthodontics
    • /
    • v.33 no.6 s.101
    • /
    • pp.437-451
    • /
    • 2003
  • The purpose of this study was to measure maximum bite force and to investigate its relationship with anteroposterior, vertical, and transverse facial skeletal measurements. From among the dental students at the College of Dentistry, forty subjects (26 male and 14 female) were selected. With two sets of strain gauge, maximum bite force at the right and left first molars and anterior teeth was measured in the morning and afternoon. After taking lateral and posteroanterior cephalograms, fifty and nineteen variables were evaluated, respectively Paired t-tests and an independent t-test were done and correlation coefficients were obtained. 1. The maximum bite force at the first molars was $68.0\pm13.9kg$. in males and $55.6\pm10.5kg$ in females (p<0.05) while the force at the anterior teeth was $8.4\pm4.9kg\;and\;1.1\pm3.4kg$ respectively (p<0.05). 2. Some tendency for a greater value of maximum bite force at the preferred side was observed but not statistically significant (p>0.05). 3. Significant difference was observed between the strong bite force group and the weak bite force group in some cephalometric and other measurements (p<0.05). N-S-Ar, S-Ar-Go, FH-Hl, IMPA and MMO showed a significant difference in posterior maximum bite force (P). N-S-Ar and FH-H1 also showed a significant difference in anterior maximum bite force (A). 4. Several cephalometric variables showed some correlation with maximum bite force (p<0.05). N-S-Ar, S-Ar-Go, UGA, FH-H6, FH-H1, body weight and MMO were significantly correlated with posterior maximum bite force (P). Go-Me, P-1 and IMPA were significantly correlated with anterior maximum bite force (A).

NEW ALGORITHMS FOR SOLVING ODES BY PSEUDOSPECTRAL METHOD

  • Darvishi, M.T.
    • Journal of applied mathematics & informatics
    • /
    • v.7 no.2
    • /
    • pp.439-451
    • /
    • 2000
  • To compute derivatives using matrix vector multiplication method, new algorithms were introduced in [1.2]n By these algorithms, we reduced roundoff error in computing derivative using Chebyshev collocation methods (CCM). In this paper, some applications of these algorithms ar presented.