• 제목/요약/키워드: Research synthesize

검색결과 499건 처리시간 0.028초

Deposition and Characterization of Graphene Materials Deposited through Thermal Chemical Vapor Deposition

  • Kwon, Kyoung-Woo;Bae, Seung-Muk;Yeop, Moon-Soo;Kim, Ji-Soo;Ko, Myong-Hee;Jung, Min-Wook;An, Ki-Seok;Hwang, Jin-Ha
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.362-362
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    • 2012
  • Graphene-based materials have been gaining the unprecedented academic and industrial applications, due to the unique charge transport as a new kind of 2-dimensional materials. The applications incorporate electronic devices, nonvolatile memories, batteries, chemical sensors, etc. based on the electrical, mechanical, structural, optical, and chemical features newly reported. The current work employs thermal chemical vapor deposition involving H2 and CH4, in order to synthesize the 2-dimensional graphene materials. The qualitative/quantitative characterizations of the synthesized graphene materials are evaluated using Raman spectroscopy and Hall Measurements, In particular, the effect of processing variables is systematically investigated on the formation of graphene materials through statistical design of experiments. The optimized graphene materials will be attempted towards the potential applications to flat-panel displays.

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척수손상인의 적응과정에 관한 근거이론적 접근 (A Ground Theory Approach to the Adaptation Process of the Spinal Cord Injured Persons)

  • 송충숙
    • 동서간호학연구지
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    • 제22권2호
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    • pp.158-169
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    • 2016
  • Purpose: This study is a qualitative research on the adaptation of the spinal cord injury after fortuitous the accident. Methods: The subjects are fifteen spinal cord injuries. As a study method, this author employed Grounded theory, one of the qualitative research methods. For data analysis, the procedures of Grounded theory methodology was adopted, and then the data collection were collected for six months from March to September 2009. Concerning the frequence of interviewing, each participants went through individual interviewing twice at least and up to four times if necessary. Results: As a result of open coding, total thirty six concepts and twenty categories were drawn. To synthesize these categories, they came to choose 'Going into the new self-made spinal cord injury' as a nuclear category. Typological analysis based on the result of the paradigm model divided them into a reality-avoiding, passive coping, reality-maintaining, reality-overcoming, and self-fulfillment type. Conclusion: As a result of this study, family support to those with spinal cord disability is an important factor for their motive for rehabilitation and adjustment, spinal disabilities were accepted to mostly the disabilities in relations with colleagues. Thus it is necessary to give them a nursing intervention through disability group for successful adjustment to life with disability.

졸겔법을 통한 TiO2 합성 및 pH에 따른 DSSC의 전기화학적 특성 (Synthesis of TiO2 by Sol-gel Method and Electrochemical Properties of DSSCs with Controlling pH)

  • 박아름;김선훈;김두근;구할본;기현철
    • 한국전기전자재료학회논문지
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    • 제25권8호
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    • pp.620-625
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    • 2012
  • The sol-gel method has been widely used to synthesize the $TiO_2$ for dye sensitized solar cells and has advantages of easily fabrication process, controlling the $TiO_2$ phase and getting transparent thin-film composed of the $TiO_2$. In this paper, we synthesized the crystalline $TiO_2$ by sol-gel method controlled by the quantity ratio of Nitric acid and Ammonium hydroxide additives. The best efficiency result was obtained by 0.05 M Ammonium hydroxide and that results of Voc, Jsc, FF, and efficiency were 0.68 V, 3.28 mA/$cm_2$, 58.14 and 5.21%, respectively.

풍화된 변성암 사면의 안정대책 사례 (Case of slope stability in weathered metamorphic rock)

  • 김재홍;박철숙;전제성;홍원표
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.1400-1405
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    • 2008
  • Execute surface of the earth geological survey for stability analysis of stealing cutting sides and investigated wide area nature of soil structure. Inflected DIPS that measure discontinuity's direction that develop to slope and is slope stability a wide use program for Stereographic Projection Method analysis that utilize geometrical correlation of stealing four sides and discontinuity surface. It is principle that angle of internal friction that is basis element of stability estimation applies direct shear test result on joint side, Examination is impossible by case execution, suppose by 30 angles that apply more conservatively in base rock slope sides usually and achieved analysis. When analyze, consider discontinuity's various adult that develop in research slope, after conduct first each discontinuity different assay falling into fault, joint, executed stability estimation which synthesize whole discontinuity data. When ailment element is recognized as analysis result, wished to present stability countermeasure way of most suitable to take into account of execution, stability, economic performance.

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Nano-sized $Gd_{2}O_{3}:Eu$ phosphor particles of high brightness

  • Lee, Chang-Hee;Roh, Hyun-Sook;Kang, Yun-Chan;Park, Hee-Dong;Park, Seung-Bin
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.791-794
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    • 2003
  • To synthesize $Gd_{2}O_{3}:Eu$ phosphor powder of nano size and high luminescence efficiency under UV (ultraviolet) and VUV (vacuum ultraviolet) light, organic additives such as citric acid and ethylene glycol and $Na_{2}CO_{3}$ flux were introduced in large-scale spray pyrolysis and critical conditions for forming nano-sized particles were investigated. The $Gd_{2}O_{3}:Eu$ phosphor particles prepared from solutions with organic additives such as citric acid and ethylene glycol had micron size and spherical shape. However, the particles prepared from polymeric precursor solution with $Na_{2}CO_{3}$ flux had nano size and non-aggregation characteristics. The as-prepared spherical particles with micron size turned into nano-sized particles during post-treatment by recrystallization process. The nano-sized $Gd_{2}O_{3}:Eu$ phosphor particles showed higher brightness than the commercial $Y_2O_3:Eu$ phosphor product under both UV light of 254nm and VUV light of 147 nm.

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엽납석을 활용한 저열팽창 코디어라이트 세라믹스 합성 (Synthesis of Low-Thermal-Expansion Cordierite Ceramics Prepared from Pyrophyllite)

  • 김동민;정숙인;이훈철;이상진
    • 한국재료학회지
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    • 제25권7호
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    • pp.330-335
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    • 2015
  • A low thermal expansion ceramic, cordierite ($2MgO{\cdot}2Al_2O_3{\cdot}5SiO_2$), was synthesized using pyrophyllite. Pyrophyllite usually consists of $SiO_2$ and $Al_2O_3$, which are the main components of cordierite. $MgCO_3$ and $Al(OH)_3$ were added in various amounts to pyrophyllite and fired for synthesis and sintering. ${\alpha}$-cordierite crystallized from $1000^{\circ}C$ with mixing of 20 wt% $MgCO_3$ and 1.7 wt% $Al(OH)_3$, and un-reacted cristobalite was also detected with the cordierite. As the temperature was increased to $1400^{\circ}C$, the cordierite yield was gradually increased. Powder compacts of the synthesized cordierite were sintered between $1250^{\circ}C{\sim}1400^{\circ}C$; the sintered samples showed a low thermal expansion coefficient of $2.1{\times}10^{-6}/^{\circ}C$ and typical sintering behavior. It is anticipated that it will be possible to synthesize cordierite ceramics on a mass production scale using the mineral pyrophyllite.

Exploring the Nature of Whistle Blowing in Organizations in Asia: An Integrative Perspective

  • IRAWANTO, Dodi Wirawan;NOVIANTI, Khusnul Rofida
    • The Journal of Asian Finance, Economics and Business
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    • 제7권11호
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    • pp.519-528
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    • 2020
  • This paper aims to synthesize and identified several constraints of the research literature about whistleblowing and its impact on the organizations from the human resource and organizational behavior point of view. The importance of study concerning whistleblowing is an important trend in this today fraudulent world, however to our knowledge an integrative review in this sense is limited. By looking at the impact of whistleblowing act in collectivist culture, especially from the Asian perspective would give an impact to the development of the studies in the future. This review using an integrative review with the distribution of databases including Sciencedirect, EBSCO, JSTOR and soon using several terms including whistleblowing and collectivist of research published during 2003 to 2018. Thirty five papers were identified, analyzed, and capturing data of research located in several Asian countries such as China, India, Indonesia, Malaysia, South Korea, Thailand and Turkey. The findings of this review reveals that despite a positive trend of whistleblowing research in collectivist culture, the importance to increase human resource and organizational behavior aspects also lead to positive ethic climate in organization. Human resource and organizational behavior aspects to be found have a significance role in creating ethical culture in the organization.

Fabrication of β-SiAlONs by a Reaction-Bonding Process Followed by Post-Sintering

  • Park, Young-Jo;Noh, Eun-Ah;Ko, Jae-Woong;Kim, Hai-Doo
    • 한국세라믹학회지
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    • 제46권5호
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    • pp.452-455
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    • 2009
  • A cost-effective route to synthesize $\beta$-SiAlONs from Si mixtures by reaction bonding followed by post-sintering was investigated. Three different z values, 0.45, 0.92 and 1.87, in $Si_{6-z}Al_zO_zN_{8-z}$ without excess liquid phase were selected to elucidate the mechanism of SiAlON formation and densification. For RBSN (reaction-bonded silicon nitride) specimens prior to post-sintering, nitridation rates of more than 90% were achieved by multistep heating to $1400^{\circ}C$ in flowing 5%$H_2$/95%$N_2$; residual Si was not detected by XRD analysis. An increase in density was acquired with increasing z values in post-sintered specimens, and this tendency was explained by the presence of higher amounts of transient liquid phase at larger z values. Measured z values from the synthesized $\beta$-SiAlONs were similar to the values calculated for the starting compositions. Slight deviations in z values between measurements and calculations were rationalized by a reasonable application of the characteristics of the nitriding and post-sintering processes.

고압환경에서의 결정 크기에 원시료의 상이 미치는 영향: 비정질 시료와 나노파우더를 이용한 시료의 결정 크기 비교 (The Effect of Phases of Starting Materials on the Grain Size at High Pressure: the Comparison of Grain Size in the Samples Using Glass and Nano Powder as Starting Materials)

  • 김은정;알레시오 잔도나;타케히코 히라가;사나에 고이즈미;노부요시 미야지마;토모오 카추라;소병달
    • 광물과 암석
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    • 제36권3호
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    • pp.213-220
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    • 2023
  • 본 연구에서는 고압 환경에서 합성된 결정 입자의 크기에 원시료(starting materials)의 상(phase)이 미치는 영향을 확인했다. 상이 다른 두 가지 원시료인 비정질 시료와 나노파우더 시료를 이용해 알루미늄이 부화된 고압의 환원환경에서 삼원계 시스템인 브리지마나이트-페리클레이스-칼슘 페라이트(calcium ferrite)상의 MgAl2O4을 합성했다. 시료는 40 GPa 2000 K의 압력온도 조건에서 20 시간 동안 가열하여 합성했다. 합성된 시료는 비정질 시료를 이용한 경우 입자 크기가 50-200 nm였으며, 나노파우더를 이용한 경우 ~500 nm로 나타났다. 이러한 차이는 1) 시료가 합성된 2000 K의 온도가 낮아 비정질 시료의 경우 결정 성장보다 결정핵 성장이 더 우세하게 나타났거나 2) 시료에 존재할 수 있는 산화 환원반응 상태의 차이로 생각된다. 추후 다원계 시스템에 대한 고압 실험을 수행할 때 비정질 시료보다 나노파우더를 원시료로 이용하는 것이 결정 성장에서 더 유리할 것으로 생각된다.

Manipulating Isoflavone Levels in Plants

  • Jung Woo-Suk;Chung Ill-Min;Heo Hwa-Young
    • Journal of Plant Biotechnology
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    • 제5권3호
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    • pp.149-155
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    • 2003
  • Metabolic engineering for production of isoflavones in nonlegume plants could distribute the health benefits of these phytoestrogens in more widely-consumed grains. Series of investigation to check the ability of the heterologous isoflavone synthase enzyme to interact with the endogenous phenylpropanoid pathway have been conducted. Overall, results provide possibility of production of isoflavonoids in several plant tissue systems including soybean and nonlegumes. In tissue that undergoes naturally enhanced synthesis of anthocyanins, genistein production was enhanced. In a monocot cell system, introduced expression of a transcription factor regulating genes of the anthocyanin pathway was effective in conferring the ability to produce genistein in the presence of the isoflavone synthase gene. However, in this case the intermediate accumulated to high levels indicating an inefficiency in its conversion. Introduction of a third gene, chalcone reductase, provided the ability to synthesize an additional substrate of isoflavone synthase resulting in production of the isoflavone daidzein. These research efforts provide insight into requirements for metabolic engineering for isoflavone production in nonlegume dicot and monocot tissues.