• Title/Summary/Keyword: $Z_2$

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Crystal Structure and Optical Property of Single-Phase (1210) Gallium Nitride Film ((1210) Gallium Nitride 단결정 박막의 결정구조 및 광학적 특성)

  • Hwang Jin Soo;Chong Paul Joe
    • Korean Journal of Crystallography
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    • v.8 no.1
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    • pp.33-37
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    • 1997
  • The optical properties of (1210) GaN epitaxy films grown on the (1012) $\alpha-A1_2O_3$ substrates have been studied. The hetero-epitaxy films were grown by the halide vapor phase epitaxy (HVPE) method using $Ga/HC1/NH_3/He$ system at $990^{\circ}C$. XRD, RHEED and SEM are used for the identification of the hetero-epitaxy films structure and surface morphology. The confirmed (1210) GaN epitaxy films were characterized by PL and Raman. By the Raman scattering, the active phonon modes of single-phase GaN films are varied with the arrangement of both polarization and propagation directions of laser beam with reference to the axis in single-phase crystal films. The Y(Z, Y & Z) X geometry allows scattering pat-terns of $A_1(TO)=533\;cm^{-1},\;E_1(TO)=559\;cm^{-1}\;and\;E_2=568 cm^{-1}$ modes, whereas in the Z(Y, Y & Z) X geometry the only $E_2$ mode are observed.

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A comparative study Program Outcome between nursing college students before and After Integrated Clinical Practice (간호대학생의 통합임상실습 전·후 학습성과의 차이)

  • Lee Oi Sun;Noh Yoon Goo
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.4
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    • pp.23-30
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    • 2023
  • This study was attempted to be used as basic data for efficient clinical practice education operation by identifying differences in program outcomes before and after integrated clinical practice of nursing students. Data collection was conducted before and after 6 weeks of integrated clinical practice for 38 nursing college students from July 19 to September 10, 2021 with a single group pre- and post-design. The collected data were analyzed by frequency, Wilcoxon sign rank, and Pearson correlation using SPSS/Win 23.0. After the integrated clinical practice, 1st program outcomes(Care integration)(Z=-4.63, p<.001), 2nd(Core practice)(Z=-3.99, p<.001), 6th(Critical thinking)(Z=-3.60, p<.001) and 11th(Research practice)(Z=-2.76, p=.005) increased significantly compared to before practice. Since integrated clinical practice was found to be an effective practice to improve program outcomes, it is suggested to actively utilize it as a strategy for improving program outcomes.

A Convergence Study about Married Couples' Attitude toward Family-Birth according to the Spouse's Participation Range of Family-Birth (배우자의 가족분만 참여범위에 따른 부부의 가족분만에 대한 태도에 관한 융합연구)

  • Lee, Sun-Young;Oh, Sangeun
    • Journal of the Korea Convergence Society
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    • v.9 no.6
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    • pp.107-116
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    • 2018
  • Purpose: The purpose of the study was to assess married couples' attitude toward family-birth according to the range of spouse's participation in family-birth. Method: Data were obtained by the 54 couples who used to visited in order to participate on family-birth at two teritary women's hospital in G-city. Result: There was a significant difference in pregnant woman's attitude : the status of having a job(Z=-2.01, p=.044) & type of nuclear family(Z=-2.17, p=.029), planned pregnance(Z=-2.54, p=.011). The spouse who partly participated in the process of family-birth showed higher(t=2.30, p=.030) compared to the spouse who participated in the whole process of family-birth. Conclusion: The results of the study suggest that hospitals and women's hospitals should support pregnant woman's social work and encourage spouse who partly participation and develop education programs.

Crystal and Block Structures of Hexagonal Ferrites (육방정 페라이트의 결정과 Block 구조)

  • Shin, Hyung-Sup
    • Journal of the Korean Ceramic Society
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    • v.49 no.3
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    • pp.205-215
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    • 2012
  • It has been studied the crystal and block structures of the hexagonal ferrites with M, W, Y and Z types prepared by various coprecipitation-oxidation method. The structures have been refined with a Rietveld analysis of the powder X-ray diffraction pattern with high precision ($R_{WP}$ <0.09, $R_I$ <0.03). The density difference between the S-blocks was proportioned to the cobalt contents in hexagonal ferrites, but that between the R or T-blocks was relatively small. Compared with the blocks and cation-oxygen polyhedra in BaM ($BaFe_{12}O_{19}$), those were bulky to the normal direction for the c-axis in $Co_2W$ ($BaCo_2Fe_{16}O_{27}$) and to the parallel direction for the c-axis in $Co_2Y$ ($Ba_2Co_2Fe_{12}O_{22}$) and $Co_2Z$ ($Ba_3Co_2Fe_{24}O_{41}$). The S-blocks of $Co_2W$, $Co_2Y$, and $Co_2Z$ were unstable and distorted. Because the T-block of $Co_2Z$ was unstable, the T-block was decomposed into the Ba-rich phase and $Co_2W$ at high temperatures above $1200^{\circ}C$. A standard powder X-ray diffraction pattern for $Co_2Z$ was proposed as well.

Study on Original Plants of and Foreign Materials Compliance Guidelines for Zanthoxyli Pericarpium (산초(山椒)의 기원(基原)식물과 이물 규격에 관한 연구)

  • Lee, Young-Jong
    • The Korea Journal of Herbology
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    • v.31 no.6
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    • pp.11-20
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    • 2016
  • Objectives : This study aims to examine validity of the following guideline for Zanthoxyli Pericarpium in the Korean Pharmacopoeia regarding foreign materials: "the seeds of Zanthoxyli Pericarpium that are mixed should not exceed 20%." Methods : Varied compliance guidelines for and original plants of Zanthoxyli Pericarpium across countries were compared and contrasted. In order to do this, pharmacopoeias from a number of different countries including Korea were used as references. Results : The weights including seed parts were Z. piperitum 3.48g, Z. schinifolium 2.94g, and Z. bungeanum 2.16g; while the weights of peel parts were Z. piperitum 1.45g, Z. schinifolium 1.69g, and Z. bungeanum 0.98g. In terms of weight, Z. piperitum was the heaviest with its entire part including the seed, whereas Z. schinifolium was the heaviest with its peel part. The proportions of each seed in the whole part were Z. piperitum 58.33%, Z. schinifolium 42.52%, and Z. bungeanum 54.63%. Considering these figures, including seed parts in the guideline up to 20% is inappropriate; however, this guideline is inevitable in order to use seed parts for medicinal purpose. Conclusion : In this article, the author argues if any changes were to made on the guideline for Zanthoxyli Pericarpium with respect to foreign materials - "the seeds of Zanthoxyli Pericarpium that are mixed should not exceed 20%" - its seed part should firsthand be separated from its peel part and be designated as one kind of medicine. Then, revisions on the foreign materials compliance guidelines for Zanthoxyli Pericarpium should also be made.

Synthesis and Superconductivity in $(Ru_{0.8}Nb_{0.2})Sr_2(Gd_{1.5-x}Nd_xCe_{0.5})Cu_2O_z$ System ($(Ru_{0.8}Nb_{0.2})Sr_2(Gd_{1.5-x}Nd_xCe_{0.5})Cu_2O_z$ 계의 합성 및 초전도 특성)

  • Lee, H.K.;Bae, S.M.
    • Progress in Superconductivity
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    • v.10 no.2
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    • pp.128-132
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    • 2009
  • Polycrystalline samples of $(Ru_{0.8}Nb_{0.2})Sr_2(Gd_{1.5-x}Nd_xCe_{0.5})Cu_2O_z$($ 0{\leq}x{\leq}1.25$) have been synthesized by a solid-state reaction route. The X-ray diffraction data revealed that the Nd solubility limit can be placed between x=0.5 and x=0.75. The superconducting transition temperature decreased with increasing Nd content, confirming that Nd entered the lattice. Room-temperature thermoelectric power measurements showed that all the samples are in the underdoped state and the partial substitution of Nd for Gd resulted in a decrease in the carrier density on the superconducting layers.

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A Comparative Analysis of Face-to-face and Non-face-to-face Education Based on the Mock Test for a Radiologist (방사선사면허 시험 대비 모의고사 중심으로 대면 교육과 비대면 교육비교 분석)

  • Kim, Yong Wan;Ahn, Beyung Ju;Lee, Jun Heang;Kim, Ju Mi;Yeo, Hwa Yeon
    • Journal of the Korean Society of Radiology
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    • v.14 no.7
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    • pp.923-930
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    • 2020
  • The COVID-19 crisis inevitably led to full-scale non-face-to-face education in 2020. The researchers selected five universities out of 48 universities in radiology and radiology departments nationwide (1.2 in 2019 and 1.2 in 2020) to examine the results of face-to-face training and non-face-to-face mock tests conducted by senior students in radiology departments and radiology departments of the national health department (12 in 2019 and 1.2 in 2020) in preparation for the license test. It turned out to be. Comparing the results of face-to-face and non-face-to-face training (two in 2019 and two in 2020), statistics were analyzed by nonparametric tests, and the results showed that there were differences in theory (Z=-2.023, p<0.05, application (Z=-2.023), p<0.05), practical skills (Z=-1.753, and p<0.05). As a result of the mock test, non-face-to-face education results in poor grades compared to face-to-face education, it is believed that lectures should be taught differently or various educational methods that can communicate with students should be combined.

Superconducting and Magnetic Properties of the $(Ru_{1-x}Ta_x)Sr_2(Gd_{1.4}Ce_{0.6})Cu_2O_z$ System ($(Ru_{1-x}Ta_x)Sr_2(Gd_{1.4}Ce_{0.6})Cu_2O_z$ 계의 초전도 및 자기적 특성)

  • Lee, H.K.
    • Progress in Superconductivity
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    • v.13 no.3
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    • pp.163-168
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    • 2012
  • The effects of Ta substitution on the superconducting and magnetic properties of the $(Ru_{1-x}Ta_x)Sr_2(Gd_{1.4}Ce_{0.6})Cu_2O_z(0{\leq}x{\leq}0.5)$ system have been investigated. The X-ray diffraction measurements indicate that the Ta ion replaces Ru sites up to x = 0.4. It is found that the Ta substitution for Ru significantly reduces the weak-ferromagnetic component of the field-cooled magnetic susceptibility without an appreciable change of room temperature thermopower at lower Ta doping level below x = 0.2. The resistive transition temperature tends to decrease monotonically from 27 K for the x = 0 sample to 16 K (9 K) for the x = 0.4 (x = 0.5) sample. These results suggest that superconductivity of the $(Ru_{1-x}Ta_x)Sr_2(Gd_{1.4}Ce_{0.6})Cu_2O_z$ compound is not significantly affected by the magnetic state of the Ru sublattice. The experimental results are discussed in connection with previous reports on the effects of Nb substitution.

Investigation of the Copper (Cu) Binding Site on the Amyloid beta 1-16 (Aβ16) Monomer and Dimer Using Collision-induced Dissociation with Electrospray Ionization Tandem Mass Spectrometry

  • Ji Won Jang;Jin Yeong Lim;Seo Yeon Kim;Jin Se Kim;Ho-Tae Kim
    • Mass Spectrometry Letters
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    • v.14 no.4
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    • pp.153-159
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    • 2023
  • The copper ion, Cu(II), binding sites for amyloid fragment Aβ1-16 (=Aβ16 ) were investigated to explain the biological activity difference in the Aβ16 aggregation process. The [M+Cu+(z-2)H]z+ (z = 2, 3 and 4, M = Aβ16 monomer) and [D+Cu+(z-2)H]z+ (z = 3 and 5, D = Aβ16 dimer) structures were investigated using electrospray ionization (ESI) mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Fragment ions of the [M+Cu+(z-2)H]z+ and [D+Cu+(z-2)H]z+ complexes were observed using collision-induced dissociation MS/MS. Three different fragmentation patterns (fragment "a", "b", and "y" ion series) were observed in the MS/MS spectrum of the (Aβ16 monomer or dimer-Cu) complex, with the "b" and "y" ion series regularly observed. The "a" ion series was not observed in the MS/MS spectrum of the [M+Cu+2H]4+ complex. In the non-covalent bond dissociation process, the [D+Cu+3H]5+ complex separated into three components ([M+Cu+H]3+, M3+, and M2+), and the [M+Cu]2+ subunit was not observed. The {M + fragment ion of [M+Cu+H]3+} fragmentation pattern was observed during the covalent bond dissociation of the [D+Cu +3H]5+ complex. The {M + [M+Cu+H]3+} complex geometry was assumed to be stable in the [D+Cu+3H]5+ complex. The {M + fragment ion of [M+Cu]2+} fragmentation pattern was also observed in the MS/MS spectrum of the [D+Cu+H]3+ complex. The {M + [y9+Cu]1+} fragment ion was the characteristic fragment ion. The [D+Cu+H]3+ and [D+Cu+3H]5+ complexes were likely to form a monomer-monomer-Cu (M-M-Cu) structure instead of a monomer-Cu-monomer (M-Cu-M) structure.

ON SUFFICIENT CONDITIONS FOR MULTIVALENT STARLIKENESS

  • Yang, Dinggong
    • Bulletin of the Korean Mathematical Society
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    • v.37 no.4
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    • pp.659-668
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    • 2000
  • Let's $S_n(p,\alpha)(p,n\in\ N={1,2,3,\cdots},0\leq\ \alpha<1)$ denote tje c;ass pf fimctopms $f(z)=z^p+a_{p+z}z^{p+n}+\cdots$ which are $\rho$-valently starlike of order $\alpha$ in the unit disk.Some criteria for a function f(z) to be in the class $S_n(\rho,\alpha)$ are given.

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