• 한국응용과학기술학회지
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• 제20권4호
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• pp.346-352
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• 2003

BaTiO$_3$, powders were prepared by sol-gel process from different aging time and reaction temperature. Particle shape, size and crystal structure of prepared $BaTiO_3$ powders were analyzed by SEM, XRD and FT-IR. Effect of aging time alternation didn't particularly show up. Spherical nano-sized $BaTiO_3$ powders were obtained from condition more than reaction temperature $55^{\circ}C$, and obtained sintered $BaTiO_3$ powders of tetragonal phase from heat-treatment at $1,100^{\circ}C$.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권11호
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• pp.561-565
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• 2004

SiO₂ thin films are fabricated using sol-gel method and dipping method. Gelation time is faster according to increasing the amount of H₂O except H₂O/Si(OC₂H/sub 5/)₄=4. Initial viscosity is highest at H₂O/Si(OC₂H/sub 5/)₄=6. Gelation time is faster according to increasing the amount of CH₃COOH. The relative dielectric constant of thin films decreases a little according to increasing the measuring frequency. The dielectric dissipation factor of thin films increases a little below 100kHz and it increases rapidly over 100kHz.

• 한국전기전자재료학회논문지
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• 제29권12호
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• pp.759-763
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• 2016

We demonstrate the utilization of ion gel gate dielectrics for operating non-volatile transistor memory devices based on polymer semiconductor thin films. The gating process in typical electrolyte-gated polymer transistors occurs upon the penetration and escape of ionic components into the active channel layer, which dopes and dedopes the polymer film, respectively. Therefore, by controlling doping and dedoping processes, electrical current signals through the polymer film can be memorized and erased over a period of time, which constitutes the transistor-type memory devices. It was found that increasing the thickness of polymer films can enhance the memory performance of device including (i) the current signal ratio between its memorized state and erased state and (ii) the retention time of the signal.

• 대한기계학회논문집B
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• 제31권2호
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• pp.116-124
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• 2007

An adsorption chiller is expected to have high energy-efficiency in utilizing the waste heat exhausted from a process. The objective of this paper is to investigate the performance of silica gel-water adsorption chiller from the cycle simulation and to provide a guideline for design of the adsorption chiller. The effect of cycle time, inlet temperature and water flow rate on the cooling capacity and COP is quantified during the cycle operation. It is found that the performance of adsorption chiller is more sensitive to the change of inlet water temperature rather than the water flow rate. It is concluded that the COP is 0.57 in the standard conditions(hot water $80^{\circ}C$, cooling water $30^{\circ}C$, chilled water inlet temperatures $14^{\circ}C$ and cycle time 420sec).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.1927-1929
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• 2005

Colloidal Silica(CS)/methyltrimethoxy silane(MTMS) sol solutions were prepared in variation with synthesizing parameters such as kinds of CS, acidity and reaction time. In order to understand its surface properties, sol-gel coating films on glass were fabricated. The coating film obtained from CS/MTMS sol had stable contact angle and more enhanced flat surface at reaction time of 24 hours. In case of the initial and final period of reaction, the coating films had unstable contact angle and more rough surface. In addition, surface of CS/MTMS sol-gel coating film was more rougher with increasing of acidity.

• 전기전자학회논문지
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• 제22권1호
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• pp.1-5
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• 2018

Sol-gel 공법을 이용하여, p-형 CuO 박막 트랜지스터를 제작하였다. 제작된 CuO 박막 트랜지스터는 copper (II) acetate monohydrate 를 전구체로 사용하였다. $500^{\circ}C$ 열처리 후에 형성된 전구체는 p-형 CuO 박막이 됨을 확인하였다. 또한 전구체를 형성하기 전 기판표면의 $UV/O_3$ 조사량에 따른 CuO 박막 트랜지스터의 전기적 특성변화에 대하여 연구하였으며, 600 초동안 $UV/O_3$를 조사한 경우 제작된 CuO 박막 트랜지스터는 $5{\times}10^{-3}\;cm^2/V{\cdot}s$ 의 이동도와 약 $10^2$의 온/오프 전류비를 보여주었다.

• 대한전기학회논문지
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• 제44권7호
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• pp.914-918
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• 1995

In this study, Pb(Zr$_{x}$ Ti$_{1-x}$ )O$_{3}$ (x=0.65, 0.52, 0.35) thin films were fabricated by Sol-Gel method. A stock solution with excess Pb 10[mol%] of Pb(Zr$_{x}$ Ti$_{1-x}$ )O$_{3}$ was made and spin-coated on the Pt/SiO$_{2}$/Si substrate at 4000[rpm] for 30[sec.]. Coated specimens were dried on the hot-plate at 400[.deg. C] for 10[min.]. Sintering temperature and time were 500~800[.deg. C] and 1~60[min.]. The coating process was repeated 6 times and the final thickness of the thin films were about 4800[A]. To investigate crystallization condition, PZT thin films were analyzed with sintering temperature, time and composition by the XRD. The microstructure of thin fulms were investigated by SEM. The ferroelectric perovskite phases precipitated under the sintering of 700[.deg. C] for 1 hours. In the PZT(52/48) composition, dielectric constant and dielectric loss were 2133, 2.2[%] at room temperature, respectively.ively.

• 한국염색가공학회지
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• 제21권4호
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• pp.39-45
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• 2009

PVA films were crosslinked with dimethylol dihydroxy ethylene urea (DMDHEU) and three polycarboxylic acids of butanetetracarboxylic acid (BTCA), citric acid and malic acid Different factors influencing the crosslinking treatment with BTCA were investigated including BTCA and sodium hypophosphite (SHP) concentration, curing temperature and time. The cured films was extracted with boiling water and gel fraction was calculated based on weight change of the PVA films. The gel fraction of PVA films increased with increasing curing temperature and time. And the resistance to water and thermal stability of the crosslinked PVA films improved with the BTCA crosslinking treatment. While crosslinking with citric acid gave the highest gel fraction among the crosslinkers, crosslinking with malic acid showed the highest absorbancy in 0.9% saline solution, which was attributed to lower crosslink density and high number-average molecular weight between crosslinks. The superabsorbent PVA films could be prepared by adjusting the crosslinking condition of PVA with polycarboxilic acids.

• E2M - 전기 전자와 첨단 소재
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• 제9권7호
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• pp.668-673
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• 1996

In this paper, (P $b_{1-x}$ L $a_{x}$)(Z $r_{0.52}$ $Ti_{0.48}$) $O_{3}$ (X=0-13[at%]) thin film were prepared by the Sol-Gel method, Multiple PLZT thin films were spin-coated on the Pt/Ti/ $SiO_{2}$Si substrate. The electrical properties of the films were investigated for varying the annealing temperature. In the PLZT(11/52/48) specimens, the dielectric ocnstant of 1236 and the polarization reversal time of 460[nm] were obtained and the breakdown of the film did not occur up to 1*10$^{10}$ cycles at the voltage of 7[V] by the bipolar acceleration. The remanent polarization and coercive field decreased with increasing the content of La in the range of 0-13[at%] and thin film of the PLZT(11/52/48) showed the value of 2.56[.mu.C/c $m^{2}$] and 21.1[kV/cm], respectively.ly.y.

• 한국지반공학회논문집
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• 제26권9호
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• pp.47-58
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• 2010

본 논문에서는 2.0 Shot 방식의 최적 주입비를 산정하고 이에 대한 주입시간과 강도에 대한 검증을 실시하였다. 따라서 본 연구를 수행하기 위하여 유제거동 지배방정식을 이용하여 최적 주입비를 산정하고 이에 대한 실내실험과 현장실험을 실시하였다. 실내실험은 주입비의 변화에 따른 주입시간의 비교, 재령과 공극비의 변화에 따른 강도 특성을 예측하기 위한 호모겔과 샌드겔의 강도실험으로 구분하여 실시하였다. 연구결과 2.0 Shot 방식의 최적 주입비는 1:2 일 경우 침투가 가장 효율적으로 나타났다. 강도 실험에서도 다른 주입비에 비해 최적 주입비가 큰 강도를 발현하는 것으로 나타났다. 또한 현장실험을 통하여 현장에서도 높은 강도가 발현될 것으로 판단된다.