• Title/Summary/Keyword: T-gap

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Electron Density and Electron Temperature in Atmospheric Pressure Microplasma

  • Tran, T.H.;Kim, J.H.;Seong, D.J.;Jeong, J.R.;You, S.J.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.152-152
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    • 2012
  • In this work we measured electron temperature and electron density of a microplasma by optical emission spectroscopy. The plasma is generated from a small discharge gap of a microwave parallel stripline resonator (MPSR) in Helium at atmospheric pressure. The microwave power supplied for this plasma source from 0.5 to 5 watts at a frequency close to 800 MHz. The electron temperature and electron density were estimated through Collisional-radiative model combined with Corona-equilibrium model. The results show that the electron density and temperature of this plasma in the case small discharge gap width are higher than that in larger gap width. The diagnostic techniques and associated challenges will be presented and discussed.

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Growth and optical properties of undoped and Co-doped CdS single crystals (CdS 및 CdS:Co2+ 단결정의 성장과 광학적 특성)

  • Oh, Gum-kon;Kim, Nam-oh;Kim, Hyung-gon;Hyun, Seung-cheol;Park, hjung;Oh, Seok-kyun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.51 no.3
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    • pp.137-141
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    • 2002
  • CdS and $CdS:Co^{2+}$ single crystals were grown by CTR method using iodine as transport material. The grown single crystals have defect chalcopyrite structure with direct band gap. The optical energy band gap was decreased according to add of Co-impurity. We can observed the Co-impurity optical absorption peaks assigned to the $Co^{2+}$ ion sited at the $T_d$ symmetry lattice and we consider that they were attributed to the electron transitions between energy levels of ions.

A Comparative Study of Consumers and Providers on Nursing Service Quality, Satisfaction, and Hospital Revisiting Intent (간호서비스 질, 만족 및 병원 재이용 의도에 관한 소비자와 제공자간의 지각차이 비교)

  • Lee, Mi-Aie;Yom, Young-Hee
    • Journal of Korean Academy of Nursing Administration
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    • v.11 no.4
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    • pp.425-437
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    • 2005
  • Purpose: The purposes of this study were to compare the nursing service quality, gap, overall nursing service satisfaction, overall medical service satisfaction and intent to revisit the hospital perceived by consumers and providers. Methods: Data were collected with self-administered questionnaire and analyzed using frequency, %, mean, standard deviation, t-test, Pearson correlation coefficient, and multiple regression analysis. Result: Nursing service gap perceived by consumers was smaller than that of providers. Consumer's overall satisfaction with nursing and medical service was higher than that of nurses. In consumers, nursing service satisfaction alone accounted for 62.9% of the variance in their intent to revisit the hospital, while explained 3% of the variance in providers. Conclusion: There are definitely perception gap between consumers and providers. Therefore nursing and hospital managers must recognize it, and carry out the internal marketing strategies for nurses.

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Application of Conformal Mapping in Analysis the Parallel Stripline Resonator

  • Tran, T.H.;You, S.J.;Kim, J.H.;Seong, D.J.;Jeong, J.R.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.180-180
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    • 2012
  • A microplasma system source based on microwave parallel stripline resonator (MPSR) was developed for the generation of microplasmas in a wide range of pressure from some torr to 760 torr. This source was operated at its resonance frequency that much depends upon not only its discharge gap size but also operated pressure. This paper applied a simple circuit model to analyze the effects of discharge gap size and pressure to resonance frequency and impedance of MPSR in the cases with and without plasma exist inside the discharge gap. In the process of calculating, the conformal mapping method was used to estimate the capacitance of the MPSR. The calculating results by using circuit model agree well with the simulation results that using commercial CST microwave studio software.

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Development of Learning Materials for Specialized Education in Collaboration with Teachers and Students (교사와 학생 간 협력을 통한 전문 교육용 학습 자료 개발)

  • Kimihide, Tsukamoto;Yasuyuki, Shii;Kim, Yun-hae
    • Journal of Engineering Education Research
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    • v.22 no.2
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    • pp.55-60
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    • 2019
  • Colleges of technology in Japan are characterized by specialized education starting from the first grades aged fifteen, making it particularly important to provide motivation for specialized subjects. The most difficult thing for teachers in the technical college is giving the motivation to a professional education to the lower grades who don't know the technology and engineering. Teachers tried to use and make a suitable example or an education material for their lecture. The generation gap with students makes it difficult for teachers to use examples of objects that students are actually familiar with in their daily life. To compensate for the generation gap with students, we asserted that education for lower grades should adopt the perspectives of students in higher grades. The relative closeness in age of lower and higher grades helps reduce the generation gap with students, which is advantageous in that teachers can share the perspectives of students.

Analysis of Good Agricultural Practices (GAP) in Panax ginseng C.A. Mayer (인삼의 GAP (우수농산물인증) 관련요소 분석)

  • Yu, Yong-Man;Oh, She-Chan;Sung, Bong-Jae;Kim, Hyun-Ho;Youn, Young-Nam
    • Korean Journal of Medicinal Crop Science
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    • v.15 no.3
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    • pp.220-226
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    • 2007
  • For the analysis of hazard factors and the development of GAP (Good Agricultural Practices) Ginseng, 10 ginseng cultural farms wished certified GAP were selected at Geumsan-gun area, a representative site of ginseng cultivation in Korea. In order to verify the safety of GAP ginseng, possible contamination of pesticide and heavy metal residues, and microbial hazard were analyzed. Soil and water around ginseng cultivation field, and ginseng were investigated. Eighty-one pesticides including carbendazim were used as typical pesticide against plant pathogens and insect pests of ginseng plant and general crops. There was no excess the maximum residue limit (MRL) in residue figure of the soil. Including the residue figure of the arsenic (0.81 ml/kg) and 7 other heavy metals was also suitable to cultivate the ginseng plant. The irrigation water and dilution water for pesticide application were also safety level for GAP. Fresh ginsengs from the farms were sampled and investigated pesticide residues and contaminations of bacteria. Among 23 pesticides tested, we didn't detect any kinds of pesticide residues, but tolclofos-methyl was frequently found in the other ginseng field. On the investigation of microorganism hazards, 2 gram negative bacteria and 1 gram positive bacterium were found in the fresh ginseng. Number of total bacteria was $1.5{\times}10^3$ cfu/ml, which was less than the other agriculture products. At these results, 10 selected ginseng farms were good cultural places for GAP ginseng production and the ginseng cultured from Geumsan-gun area were a good safe far human.

Splitting effect of photocurrent for $CdIn_2Te_4$ single crystal

  • You, Sang-Ha;Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.84-85
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    • 2009
  • The single crystals of p-$CdIn_2Te_4$ were grown by the Bridgman method without the seed crystal. From photocurrent measurements, it was found that three peaks, A, B, and C, correspond to the intrinsic transition from the valence band states of $\Gamma_7(A)$, $\Gamma_6(B)$, and $\Gamma_7(C)$ to the conduction band state of $\Gamma_6$, respectively. The crystal field splitting and the spin orbit splitting were found to be 0.2360 and 0.1119 eV, respectively, from the photocurrent spectroscopy. The temperature dependence of the $CdIn_2Te_4$ band gap energy was given by the equation of $E_g(T)=E_g(0)$ - $(9.43\times10^{-3})T^2$/(2676+T). $E_g(0)$ was estimated to be 1.4750, 1.7110, and 1.8229 eV at the valence band states of A, B, and C, respectively. The band gap energy of $p-CdIn_2Te_4$ at room temperature was determined to be 1.2023 eV.

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Characterization for $AgGaS_2$ single crystal thin film grown by hot wall epitaxy (Hot Wall Epitaxy(HWE)법에 의해 성장된 $AgGaS_2$ 단결정 박막의 특성)

  • Lee, Gyoun-Gyo;Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.101-102
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    • 2006
  • A stoichiometric mixture of evaporating materials for $AgGaS_2$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films. $AgGaS_2$ mixed crystal was deposited on thoroughly etched semi-Insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were $590^{\circ}C$ and $440^{\circ}C$, respectively. The temperature dependence of the energy band gap of the $AgGaS_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=2.7284 eV-(8.695{\times}10^{-4} eV/K)T^2/(T+332 K)$. After the as-grown $AgGaS_2$ single crystal thin films was annealed in Ag-, S-, and Ga-atmospheres, the origin of point defects of $AgGaS_2$ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K.

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Studies of point defects for annealed $AgInS_{2}/GaAs$ epilayer

  • Kwang-Joon Hong;Seung Nam Baek;Jun Woo Jeong
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.12 no.4
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    • pp.196-201
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    • 2002
  • The $AgInS_{2}$ epilayers with a chalcopyrite structure grown using a hot-wall epitaxy method have been confirmed to be a high quality crystal. From the optical absorption measurements, a temperature dependence of the energy band gap on $AgInS_{2}/GaAs$ was found to be $Eg(T)=2.1365eV-(9.89{\times}10^{-3}eV)T^{2}/(2930+T)$. After the as-grown $AgInS_{2}/GaAs$ was annealed in Ag-, S-, and In-atmospheres, the origin of point defects of $AgInS_{2}/GaAs$ has been investigated by using photoluminescence measurements at 10 K. The native defects of $V_{Ag},\;V_{S},\;Ag_{int}$ and $S_{int}$ obtained from photoluminescence measurements were classified as donors or accepters. It was concluded that the heat-treatment in the S-atmosphere converted $AgInS_{2}/GaAs$ to an optical p-type. Also, it was confirmed that In in $AgInS_{2}/GaAs$ did not form the native defects because In in $AgInS_{2}$ did exist in the stable form.

Photocurrent Study on the Splitting of the Valence Band and Growth of $CdIn_2Te_4$ Single Crystal by Bridgman method (Bridgman법에 의해 성장된 $CdIn_2Te_4$ 단결정의 가전자 갈라짐에 대한 광전류 연구)

  • Baek, Seung-Nam;Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.347-351
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    • 2003
  • A p-$CdIn_2Te_4$ single crystal has been grown by the Bridgman method without a seed crystal in a tree-stage vertical electric furnace. From photocurrent measurements, it was found that three peaks, A, B, and C, corresponded to an intrinsic transition due to the band-to-band transition from the valence band states ${\Gamma}_7(A),\;{\Gamma}_6(B),\;and\;{\Gamma}_7(C)$ to the conduction band state ${\Gamma}_6$, respectively. Also, the valence band splitting of the $CdIn_2Te_4$ crystal has been confirmed by photocurrent spectroscopy. The crystal field splitting and the spin orbit splitting were obtained to be 0.2360 and 0.1119 eV, respectively. Also, the temperature dependence of the band gap energy of the $CdIn_2Te_4$ crystal has been driven as the following equation of $E_g(T)\;=E_g(0)\;-\;(9.43\;{\times}\;10^{-3})T^2/(2676\;+\;T)$. In this equation, the Eg(0) was estimated to be 1.4750, 1.7110, and 1.8229 eV at the valence band state A, B, and C, respectively. The band gap energy of the p-$CdIn_2Te_4$ at room temperature was determined to be 1.2023 eV.

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