• 제목/요약/키워드: Sol Characteristics

검색결과 718건 처리시간 0.042초

선운사 입지의 공간구성과 가람 배치 (Space Composition and Layout of the Location of Seon-Un Temple)

  • 배영한;박정해
    • 산업진흥연구
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    • 제9권2호
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    • pp.137-151
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    • 2024
  • 본 연구는 고창 도솔산(兜率山) 선운사(禪雲寺) 입지에 대한 풍수적인 특징을 현장조사와 문헌고찰을 통해 형세론적 관점과 이기론 관점에서 분석한 연구이다. 풍수가 갖는 특징적인 요소는 자연과 조화를 최우선 하며 합리적인 방법을 통하여 입지선정의 기준점으로 삼았다. 신라시대 입당승들은 형세풍수가 처음 나타난 강서지역에 유학을 하였는데, 강서지법의 형세풍수가 우리나라에 유입되어 사찰의 입지선정과 가람배치에 주도적인 역할을 했다. 선운사는 도솔산 아래에 입지하여 그 의미가 클 수밖에 없었고, 부처님의 나라로 들어가는 도솔천(兜率川)과 도솔암(兜率庵)을 통한 불교적 완성을 이루고자 하는 바람의 실천이었다. 따라서 고창 도솔산(兜率山) 아래에 자리한 선운사 입지에는 다양한 풍수적 특징이 반영되었는데, 특히 도솔산 선운사의 입지에는 풍수가 가지고 있는 특징과 의미를 논리적으로 사용하였고, 불교의 가장 신성한 의미를 갖는 불교 교리와 사상 전파를 목적으로 하는 자연과 하나되는 모습을 실천하였다.

Sol-Gel법에 의한 ZnO 분말의 CO 센서 특성 (CO Sensor Characteristics of ZnO powders by Sol-Gel methods)

  • 박보석;박진성;노효섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.821-825
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    • 2002
  • ZnO thick films by Sol-Gel processing were investigated electrics, optics and the sensing characteristics of CO gas. Using the znic acetate dihydrate and acetylaceton (AcAc) as a chelating agent, stable ZnO sol was synthesized. ZnO phase was crystallized through the heat-treatment at $70^{\circ}C$ for 4hrs and influenced the sensing characteristics of the electrics and CO gas by uniform particle distributions not related particle size. The samples on the alumina substrate by thick films were investigated the properties of electrics and the effect of sensing. The sensitivity was so excellent in the sample of the heat-treatment at $600^{\circ}C$ for 12hrs and good in the heat-treatment for 1hrs generally. Crystallization and volatilization of organic materials according to the change of heating treatment temperature of thick films were analyzed by TG-DTA, XRD and mirostructure of thick films were observed by SEM.

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Sol-Gel법으로 제작된 광메모리영역 PLZT박막의 전기적 특성 (A Study on the Electrical Characteristics of Optical Memory PLZT Thin Films)

  • 최형욱;장낙원;백동수;박정흠;박창엽
    • 한국전기전자재료학회논문지
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    • 제11권1호
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    • pp.57-61
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    • 1998
  • In this study, PLZT stock solutions were prepared by Sol-Gel processing after the compositions were selected in the memory region of PLZT bulk phase diagram. PLZT solutions were deposited on the ITO glass substrate by spin-coating method. The thin films were annealed by rapid thermal processing. The electric characteristics, hysteresis loop, C-V characteristics of thin films in the memory region were measured in order to investigate the electrical characteristics of PLZT thin films. In selected compositions the decrease in Zr/Ti ratio led to an increase in dielectric constant and the decrease in remanent polarization and coercieve field which brought about slim hysteresis loop.

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제조방법에 따른 TiO2의 광촉매 특성 분석 (Photocatalytic Properties of TiO2 According to Manufacturing Method)

  • 이홍주;박유강;이승환;박정훈
    • Korean Chemical Engineering Research
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    • 제56권2호
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    • pp.156-161
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    • 2018
  • 염소법과 졸-겔법으로 $TiO_2$ 광촉매 분말을 제조하였다. 제조방법 및 조건에 따라 촉매의 결정상 형태(아나타제와 루타일)와 비표면적이 변화하는 것을 알 수 있었다. TTIP-sol로 제조한 광촉매가 염소법이나 TBOT-sol로 제조한 광촉매에 비해 methylene blue (MB) 분해 특성이 더 높았으며, 수용액상의 90% 이상의 MB를 제거할 수 있었다. 실험 결과를 통해 $TiO_2$ 광촉매는 단일 아나타제상와 큰 비표면적을 가지면 유기물 분해 특성을 향상될 수 있는 것을 확인하였다.

Alumina Sol을 코팅한 BOPP 복합체의 제조 및 기체 투과 특성 (Preparation of Alumina Sol Coated BOPP Composites and Their Gas Permeation Characteristics)

  • 홍성욱;오재원;고영덕;송기창
    • 멤브레인
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    • 제19권1호
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    • pp.19-24
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    • 2009
  • 졸-겔 공정은 비교적 간단하고 사용이 편리하며 저렴한 설비투자비가 소요되면서도 우수한 물성 및 차단특성을 갖는 코팅 박막을 얻을 수 있다는 장점이 있다. 졸-겔 공정으로 코팅된 필름은 산소 등의 영향에 의해 부패되기 쉬운 식품, 음료, 약품, 의약품 등의 포장재나 단열제로 응용 가능하다. 본 연구에서는 aluminum isopropoxide를 출발물질로 하여 alumina sol을 제조한 후 실란 커플링제를 첨가하여 코팅 용액을 제조하였다. 또한, 제조된 alumina sol 용액을 이축연신 폴리프로필렌(BOPP)에 코팅하여 복합 필름을 만들고 산소 투과 특성을 측정한 결과 순수한 BOPP에 비해서 산소 투과도가 약 85% 정도 감소되는 효과를 보였다.

졸-겔 방법으로 제조한 ZnO 쇼트키 다이오드의 특성 연구 (Schottky diode characteristics of a sol-gel driven ZnO)

  • 한광준;강광선;김재환
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1733-1736
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    • 2008
  • ZnO thin films with preferred orientation along the (0 0 2) plane were fabricated by a sol-gel method. The effects of the annealing temperature, time, and thickness were studied by investigating UV-visible spectra, FT-IR spectra, and XRD of ZnO films. The films were dried and annealed ed at $100^{\circ}C,\;200^{\circ}C$, and $300^{\circ}C$ for 1hr, 2hrs, and 3hrs, respectively. The film showed the preferred (0 0 2) orientation and high transmittance near 90% in the visible range. Also, SEM images of the films exhibited very smooth surfaces without holes and cracks. Schottky diodes were fabricated by using ZnO sol-gel material. Au and Al were used as electrodes to make Ohmic and Schottky contacts, respectively. The annealing temperature, time and the thickness dependent I-V characteristics were presented in this article.

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졸-겔법에 의한 이트리안 안정화 지프코니아박막의 결정화 (Crystallization of Yttria-Stabilized-Zirconia Film by Sol-Gel Process)

  • 서원찬;조차제;윤영섭;황운석
    • 한국표면공학회지
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    • 제30권3호
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    • pp.183-190
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    • 1997
  • Fabrication and crystallization characteristics of yttria($T_2O_3$) stabilized zirconia(YSZ) thin film by sol-gel process were studied. YSZ sol was synthesized with zirconium n-propoxide($Zr(OC_3H_7)_4)$) and yttrium nitrate pentahydrate ($Y(NO_3)_3.5H_2O$). YSZ film was prepared by depositing the polymeric sol on porous $Al_2O_3$ substrate by spin-coating, and the film characteristics were investigated by FRIR, TG-DTA, XRD, DSC, optical microscopy and SEM. The film topology was uniform and cracks were not found. It was found that the annealing temperature and the concentration of stabilizer affect the crystallization of YSZ film. The YSZ film began to crystallize from amorphous to tetragonal phase at 40$0^{\circ}C$, and it was not converted to cubic structure until $1100^{\circ}C$. It seemed that the grains were formed over $700^{\circ}C$and the average grain size was obtained about 0.2$\mu\textrm{m}$.

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졸-겔법을 이용한 Al2O3가 분산된 TZP 단섬유의 제조 (Fabrication of Discontinuous Al2O3-Dispersed TZP Fibers by a Sol-Gel Method)

  • 심수만
    • 한국세라믹학회지
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    • 제52권1호
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    • pp.56-60
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    • 2015
  • Discontinuous, polycrystalline $Al_2O_3$-dispersed TZP fibers were prepared by the centrifugal spinning of a colloidal $ZrO_2$ sol containing Y and Al nitrates and poly(vinyl alcohol). Factors affecting the rheological properties of the sols, such as sol concentrations, aging, and the amounts and types of additives, were investigated by measuring the shear viscosities. The flow characteristics of the sols were studied in relation to the spinnability by measuring the viscosity with respect to the shear rate. The spinnability was obtained through the addition of a polymer which increases the viscosity to a range of optimum viscosity values for spinning. Aging the sols containing the additives did not noticeably change the sol viscosities at room temperature up to 30 days. The flow behavior of the spinnable sols progressively changed from nearly Newtonian to pseudoplastic with an increase in the sol concentration.

Sol-Gel 반응으로 유도된 LAS의 상 생성과 점성 특성 (Phase Formation and Rheological Characteristics of LAS Derived from the Monophasic Sol-Gel Route)

  • 장현명;김광수;정창주
    • 한국세라믹학회지
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    • 제28권5호
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    • pp.365-372
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    • 1991
  • LAS (lithium aluminosilicate) sol was synthesized using the hydrolysis-condensation reaction of TEOS, chelated Al(OBus)3 and Li-salt with H2O in alcohol (EtOH+2-Propanol) medium. Effects of important reaction parameters on the properties of sol and gel-derived LAS were examined. The crystallization of the sol-gel derived LAS with ${\beta}$-spodumene composition began at ∼600$^{\circ}C$, and a series of polymorphic transformations occurred as temperature was increased to 1100$^{\circ}C$: amorphous LAS\longrightarrowhexagonal LiAl(SiO3)2\longrightarrow${\beta}$-spodumene. Lowering Li content in the gel enhanced densification and retarded the crystallization significantly. Optimum reaction conditions of LAS sol formation for thin coating applications were derived from rheological measurements, and these can be summarized as: H2O/total alkoxides molar ratio=4, pH=∼2.5, and aging time of ∼250h.

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