• Title/Summary/Keyword: Orientation Relationship

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A TEM Study on Growth Characteristics of GaN on Si(111) Substrate using MOCVD (Si(111) 기판 위에 MOCVD 법으로 성장시킨 GaN의 성장 특성에 관한 TEM 분석)

  • 신희연;정성훈;유지범;서수정;양철웅
    • Journal of the Korean institute of surface engineering
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    • v.36 no.2
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    • pp.135-140
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    • 2003
  • The difference in lattice parameter and thermal expansion coefficient between GaN and Si which results in many defects into the grown GaN is larger than that between GaN and sapphire. In order to obtain high quality GaN films on Si substrate, it is essential to understand growth characteristics of GaN. In this study, GaN layers were grown on Si(111) substrates by MOCVD at three different GaN growth temperatures ($900^{\circ}C$, $1,000^{\circ}C$ and $1,100^{\circ}C$), using AlN and LT-GaN buffer layers. Using TEM, we carried out the comparative investigation of growth characteristics of GaN by characterizing lattice coherency, crystallinity, orientation relationship and defects formed (transition region, stacking fault, dislocation, etc). The localized region with high defect density was formed due to the lattice mismatch between AlN buffer layer and GaN. As the growth temperature of GaN increases, the defect density and surface roughness of GaN are decreased. In the case of GaN grown at $1,100^{\circ}$, growth thickness is decreased, and columns with out-plane misorientation are formed.

An Importance-Performance Analysis(IPA) on the Leadership Competency of Rural Community Leaders (지역사회리더 리더십역량의 중요-성취도 분석)

  • Park, Eun-Shin;Lee, Chae-Shik;Park, Duk-Byeong;Ko, Jeong-Sook
    • Journal of Korean Society of Rural Planning
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    • v.12 no.1 s.30
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    • pp.59-66
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    • 2006
  • The purposes of this study were to identify leadership competences of rural leaders and to analyze leadership competency of leaders. The study carried out by questionnaire and focus group interview on expert panels. To analyze leadership competency, the data was collected from 273 rural leaders by stratified random sampling. SPSSWIN/ver10 program was used for analyzing data with t-test and IPA method. The study suggests twenty low types of leadership competences which were information, vision, decision making, motivation communication, education residents, managing residents, loaming, flexibility, problem solving, presentation program management, customer orientation service knowledge, making relationship, creative idea, business understanding, brand development, conflict resolution negotiation, assessment, business management, coaching and feed back. Whereas leaders with middle school educational career required developing program management, maintaining achievement and benchmarking, leaders with high school were morel likely to develope self-learning, to benchmark their knowhow and brand development competency. Whereas leader with less low years experiences as leader have been considered as developing coaching/feedback brand development and program development, leaders with more five years as leader should consider developing benchmarking, resident education, and brand development. The study suggests that the extension agents on public should develop leadership program according to the competency differences of leaders.

Sericitization of Tourmaline in a Pegmatite: a HRTEM Study (페그마타이트에서 산출하는 전기석의 운모화작용: 고분해능 투과전자현미경(HRTEM) 연구)

  • 안중호;이정후
    • Journal of the Mineralogical Society of Korea
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    • v.9 no.1
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    • pp.7-16
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    • 1996
  • Partially sericitized tourmaline from a pegmatite, Black Hills, South Dakota, U.S.A., was investigated using high-resolution transmission electron microscopy (HRTEM). Muscovite occurs as the only alteration product of tourmaline, and it is developed extensively as narrow veinlets along the {110} and {100} cleavage directions of tourmaline, indicating that a cleavage-controlled alteration mechanism was dominant. Muscovite was characterized mainly as two-layer polytypes with minor stacking disorder, but tourmaline is almost free of structural defects. HRTEM images of tourmaline-muscovite interfaces revealed that the interfaces between two minerals are composed of well-defined {110} and {100} boundaries of tourmaline. The (001) of muscovite is in general parallel to the c-axis of tourmaline, but tourmaline and replacing muscovite do not show specific crystallographic orientation relationship; muscovite consists of numerous 100-1000$\AA$ thick subparallel packets, and the angles between the (001) of muscovite and (110) of tourmaline is highly variable. Al/Si ratios of both minerals suggest that tourmaline to muscovite alteration by late magnetic fluids has been facilitated by their similar Al/Si ratio in the incipient alteration stage, in that the hydration reaction with preservation of Al and Si would require only addition of K+ and H2O. Aluminous minerals other than muscovite were not characterized as the alteration products of tourmaline, indicating that tourmaline reacted directly to muscovite; the tourmaline alteration apparently occurred by the presence of residual fluids in which K+ is available and silica was not undersaturated.

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Home Environment, Moral Judgement, and Moral Behavior in Childhood (아동의 가정환경과 도덕적 판단능력 및 도덕적 행동과의 관계)

  • Yo, In Sook
    • Korean Journal of Child Studies
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    • v.6 no.1
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    • pp.75-92
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    • 1985
  • The purpose of this study was to investigate the relationship between the psychological/physical home environment, and children's moral judgement and moral behaviors. The subjects for this study were a normal group of 58 children and a delinquent group of 54 children. The normal children were selected from elementary and middle schools in Taegu city, and the delinquent children were from two juvenile prisons in the Taegu area. Children's moral judgement scores were measured by levels of moral judgement as conceptualized by Kohlberg. The major findings of this study were that: 1) There were significant differences between the normal and delinquent groups on democratic conduct, permissive attitude, degree of intimacy between parent and child, and materialism orientation. 2) There were significant differences between the normal and delinquent group on life or death of real parent, living with parents, separation, bereavement or divorce, mother's age, father's educational level, and father's occupational level. 3) There were significant differences between the normal and delinquent group on children's moral judgement scales. 4) Father's educational level was the best index for predicting psychological and physical home environment variables and differences between normal and delinquent children on level of moral judgement.

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Investigation on Rock Slope Failure in Odong 2 area, Boeun-Gun (보은군 회북면 오동리 2지구 암반 절개면의 붕괴원인 고찰)

  • Koo, Ho-Bon;Baek, Yong;Kim, Gyu-Han;Rhee, Jong-Hyun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.535-542
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    • 2000
  • The investigated cut-slope is located in Odong-Ri, Hoebuk-Myun, Boeun-Gun and composed of quartzite and phyllitic rocks (approximately 80 meters in length and 25 meters in height). During the investigation, the groundwater which was inferred to the natural pipe of slope was continuously flowing in the upper part of slope. The investigation for discontinuity properties in this area was carried out to decide the rock mass rating and strength parameters. To analyze the stability of cut-slope, lower equal-area hemisphere projection method was used. And laboratory test was done to evaluate engineering properties of soil which was sampled in the non-failure and failure area The inferred causes of cut-slope failure are the geometric relationship between the orientation of cut-slope and geological structures such as joints, faults which is distributed in the slope. And direct cause of failure is the increase of water content due to the heavy rainfall.

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Estimation of principle stress field by Televiewer data analysis (텔레뷰어 자료분석을 통한 암반 내 수평 주응력 방향 산출)

  • Kim, Jung-Yul;Kim, Yoo-Sung;Nam, Ji-Yeon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.815-822
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    • 2004
  • A knowledge of in situ stress state is important to design various engineering structures such as dams, tunnels and so on. There are about three wellknown indicators that is, borehole will breakouts, hydraulic fracturing, ellipsoidal cross section of borehole that have been attributed to the state of stress in the vicinity of borehole. Fortunately, Televiewer traveltime image can be used as a caliper log with 144 or 288 arms, which allows to determine the borehole shape. Televiewer amplitude image will give detailed information about the distribution and character of breakouts and hydraulic fracturing as well. For investigation purposes, a series of boreholes(total 195 boreholes: 12.239m) that have been logged all over the country during past 10 years are analyzed. The primary objective of this paper are to examnine the ability of a Televiewer to determine the shape of borehole, to present data inferred by stress indicators, to indicate their possible relationship with the anisotropic horizontal stresses. It is shown that in most cases the fracture orientation statistically estimated from observed fractures denotes an excellent correlation with the orientations inferred by stress indicators. Many intervals of breakouts are terminated at the intersection of oblique fracture with the borehole. The results from Televiewer data are further compared with those of hydraulic fracturing techniques.

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Phase Decomposition and Strength of B2-Ordered (Ni,Co)Al (B2형 규칙(Ni,Co)Al의 상분리와 강도)

  • Han, Chang-Suck;Kim, Youn-Che
    • Journal of the Korean Society for Heat Treatment
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    • v.9 no.2
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    • pp.79-90
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    • 1996
  • Transmission electron microscopy(TEM) investigation on the phase decomposition of B2-ordered (Ni,Co)Al supersaturated with Ni and Co has revealed the precipitation of $(Ni,Co)_2Al$ which has not been expected from the reported equilibrium phase diagram. The $(Ni,Co)_2Al$ phase has a hexagonal struture and takes a rod-like shape with the long axis of the rod parallel to the <111> directions of the B2 matrix. By aging at temperatures below 873 K, a long period Superlattice Structure appears in the hexagonal $(Ni,Co)_2Al$ Phase. The orientation relationship between the $(Ni,Co)_2Al$ Precipitates and the B2-(Ni,Co)Al matrix is found to be$(0001)_p$ // $(111)_{B2}$ and $[\bar{1}2\bar{1}0]_P$ // $[\bar{1}10]_{B2}$, Where the suffix p and B2 denote the $(Ni,Co)_2Al$ precipitate and the B2-(Ni,Co)Al matrix, respectively. (Ni,Co)Al hardens appreciably by the fine precipitation of the $(Ni,Co)_2Al$ phase. Energy dispersive spectroscopy was used to analyze the compositions of each phase formed in B2-(Ni,Co)Al.

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Preparation of $Ba_{1-x}Sr_xTiO_3$thin films by metal by metal-organic chemical vapor deposition and electrical properties. (Preparation of $Ba_{1-x}Sr_xTiO_3$ thin films by metal-organic chemical vapor deposition and electrical properties)

  • Yoon, Jong-Guk;Yoon, Soon-Gil;Lee, Won-Jae;Kim, Ho-Gi
    • Journal of the Korean Vacuum Society
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    • v.5 no.1
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    • pp.62-66
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    • 1996
  • $(Ba_{1-x}Sr_xTiO_3$ (BST) thin films have been grown on Pt-coated MgO by metal -organic chemical vapor deposition. X-ray diffraction results showed that BST films were grown on a Pt/MgO substrate with (100) preferred orientation perpendicular to the surface. The lineawr relationship of P-E curve obtained form hysteresis loop measurement indicated that the BST films had a Curie transitions below room temperature . Films deposited at $900^{\circ}C$ exhibited a smooth and dense microstructure, a dielectric constant of 202, and a dissipation facotr of 0.02 at 100kHz. The leakage current density of the BST films is about $2\times10^{-10} \;A/\textrm{cm}^2$$ at an applied electric field of 0.2 MV/cm. The electrical behavior on the current-voltage characteristics is well explained by the bulk-limited Pool-Frenkel emission.

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The Structural Relationship among CSV, Club Identification, Club Emotion, Club Loyalty for Professional Volleyball Club

  • Jung, Sang-Ok;Kim, Seyun;Son, WonHo
    • International journal of advanced smart convergence
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    • v.9 no.2
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    • pp.195-202
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    • 2020
  • The ultimate goal of CSV activities is to increase consumer loyalty to the company, brand or organization concerned. Thus, for a professional sports club, CSV activities will ultimately aim to enhance the loyalty of spectators who are consumers of the club. Subjects of this study are the spectators of professional volleyball. We distributed 300 survey to people who were aware of the club's CSV activities among the home spectators of Hyundai Capital SkyWalkers. Data processing was performed using SPSS 23 and AMOS 18 for the analysis of confirmed factors, correlation analysis, reliability analysis, and structural equation model analysis. From these results, we were able to come up with the social problem resolution and long-term orientation among the CSV activities of professional volleyball clubs which affect the club identification. And the identification formed within the spectators of the clubs through CSV affects the club loyalty directly or through the medium of club emotion. Professional volleyball clubs need to identify the problems the community has in planning and proceeding with CSV activities and seek strategies to address them together, and approach them from a long-term oriented perspective.

The Ferroelectric Frequency characteristics of $Bi_{4-x}La_{x}Ti_{3}O_{12}$ ceramics with the variation of Lanthanum additives (La 첨가량에 따른 $Bi_{4-x}La_{x}Ti_{3}O_{12}$ 강유전체의 주파수특성)

  • Kim, Eung-Kwon;Park, Bok-Gi;Park, Gi-Yub;Park, Choon-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.463-466
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    • 2001
  • In recent year, Ferroelectric $BLT(Bi_{4-x}La_{x}Ti_{3}O_{12})$ is a promising candidate materials. This study was practiced to make good conditions of BL T targets. In this study, calcination and sintering temperature were kept at $750^{\circ}C$, $1100^{\circ}C$ for 2 hour respectively. the density obtained 7.612, 7.98, $7.877g/cm^{3}$ as $La_{2}O_{3}$ contents were 0.0mol%, 0.25mol%, 0.5mol%. Especially, the lanthanum content of 0.5 mol% measured C-axis (117) preferred orientation more than the others targets in the XRD. In $\varepsilon_{r}-f$ relationship using by HP 4194 A impedance analyzer, the 0.5 mol% observed above 200 relative dielectric constant. but the dissipation factor was higher than others targets at 100Hz~13MHz range. SEM photograph with the content of $La_{2}O_{3}$ was observed like rod and plate types.

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