• 한국세라믹학회지
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• 제28권12호
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• pp.943-952
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• 1991

Lead zirconate titanate(PZT) powders and thin films were prepared from an alkoxide-based solution by sol-gel method. Gelation of synthesized complex solutions, pyrolysis and crystallization behaviors of the dried powder were studied in accordance with a water content and a catalyst. PZT thin films were formed by spin-casting method on silicon and platinum substrates, and characterized. Ester produced from the reactions was completely removed when drying of the gel was finished. Pyrolysis property of the dried PZT gels were changed in order water content, class of catalyst, and quantity of catalyst. Crystalline Pb phase was transiently formed near 250$^{\circ}C$. Basic catalyst is good additive for a formation of perovskite phase in the films, and acidic catalyst for a densified film structure. By the analysis of RBS, Pb element in the PZT films were diffused into silicon substrate, and the pores, may be produced due to local densification around some grains in the films, make an origin of fault in microstructure when holding time goes to be longer at 700$^{\circ}C$.

• 한국전기전자재료학회논문지
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• 제17권2호
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• pp.178-183
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• 2004

PBT thin film was known to be a representative for the FeRAM devices because of its good ferroelectric proporties and the ease in fabricating the thin film. However, there have been several problems such as polarization fatigue and leakage current in memory devices with a PZT thin film. In this study, Sm-dolled PZT thin films were fabricated by the so1-gel method, and their ferroelectric and dielectric proportrics were compared as a function of Sm content. We investigated the effect of the Sm dopant on structural and electrical properties of PZT film. Sm-doped PZT thin films on the Pt/Ti/SiO$_2$/Si substrates have been prepared by a sol-gel method. The remanent polarization and coercive field decreased with increasing the concentration of Sm. The dielectric constant and dielectric loss decreased with Increasing Sm content. Sm-doped PZT thin films showed improved fatigue characteristics compared to the undoped PZT thin film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.48-51
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• 1997

(Pb. La)TiO$_3$ thin films were fabricated by sol-gel Processing and spin-coated on the Pt substrate. The spin-coated PLT films were sintered at 75$0^{\circ}C$ for 5min by rapid thermal ann La content dependence of the electrical properties of the PLT thin films are discussed. Wit La mole% from 20 to 36mo1e%. the dielectric constant of the PLT thin films decreased f 570. P-E hysteresis loops changed from ferroelectric to paraelectric. and the charge storage charging time decreased. The Curie Point decreased with increasing La content. The leak density also decreased and La 36mo1% species shows mood characteristics less than 10- electric field 500 (KV/cm) Because of the broad range of composition-controlled ferroelectric PLT thin films are suitable for memory application.

• KSBB Journal
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• 제17권1호
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• pp.54-58
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• 2002

소수성 결합을 가지는 커들란 겔의 특성을 이용하여 지용성물질을 포함한 겔을 제조할 수 있었고, 지용성물질의 종류에 따라 건조시킨 겔 속에 상당한 양이 포함되는데, DHA는 건조중량의 90%가지 포함될 수 있었다. 또한, $\beta$-CD의 포접특성을 이용하여 DHA를 포함시킬 때 포접체 형성에 대한 물과 에탄올의 영향을 살펴본 결과 물 2.0 mL과 에탄올 0.5 mL이 DHA 포접에 효과적이었다. FT-IR과 XRD로 포접체를 분석해 본 결과 DHA를 포함한 포접체가 형성되었고, SEM을 통하여 포접체와 커들란, 플루란을 이용하여 마이크로 캡슐의 형태를 살펴볼 수 있었다.

• 한국세라믹학회지
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• 제28권6호
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• pp.488-494
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• 1991

In this study, the effects of catalyst and DCCA content were investigated in order to determine the optimum conditions of monolithic silica gel formation through sol-gel process. Formamide, oxalic acid, glycerol and dimethylformamide are used as DCCA. To observe the phenomena in drying and heat-treating of gels, we examined structural exchange of gels using FT-IR, TG-DTA and XRD. Monolithic gels were obtained by adding formamide and dimethylformamide as DCCA. According to the heat treatment schedule, silica glass is prepared by heat-treatment up to 1050$^{\circ}C$.

• 펄프종이기술
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• 제34권1호
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• pp.22-29
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• 2002

The coated paper was greatly affected by the basic physical properties of the binder as well as the amount of the coating formula. High glass transition temperature (Tg) of the styrene-butadiene (SB) latex, selected as the binder in our study, gave the high stiffness to the coated paper, but lowered the binding force and print gloss. The average particle size of the SB latex also greatly affected to the coated paper so that the smaller particle size improved the rheological property of the coating formula and increased the binding force and print gloss. Another property of the SBR latex, gel content, was important because when its value was small, the latex was easily deformed at the high temperature and increased air permeability to the coated paper. Therefore, the lower gel content consequently resulted in the higher blistering resistance, especially in the web paper. The larger portion of the SB latex in the coated formula improved the binding force and print gloss, but decreased the ink set-off and ink-trapping to the coated paper. The heavier coating improved optical properties such as opacity, paper gloss and paper smoothness, to the coated paper.

• Asian-Australasian Journal of Animal Sciences
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• 제18권9호
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• pp.1217-1220
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• 2005

Random amplified polymorphic DNA (RAPD-PCR) analysis of 56 animals of four different genetic groups of dwarf cattle in Kerala was done as a single step analysis. Bandsharing (BS) values were calculated for animals of each group and between groups as an analytical tool to find out genetic variation among animals. The different factors affecting BS values were estimated using Harvey''s Least squares analysis. The effects of genetic group, Guanine-cytosine (GC) content of primer and gel on BS values were found significant. Bandsharing values of Kasargode-Highrange dwarf animals were significantly different from Vechur, Vatakara and their combinations. The Vechur, Vatakara and Vechur-Vatakara combinations were found to be more uniform (high BS value) compared with other combinations. The bandsharing value was lowest with primers of GC content 90% and highest with 80% GC content. The effect of gel on BS value points to the need of adjustments of gel factor for calculation of BS values.

• Journal of Magnetics
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• 제20권3호
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• pp.246-251
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• 2015

This study was aimed to study the effect of Zn content on the hyperfine parameters and the structural variation of $Ni_{1-x}Zn_xFe_2O_4$ for x = 0, 0.2, 0.4, 0.6, and 0.8. To achieve this, a sol-gel route was used for the preparation of samples and the obtained ferrites were investigated by X-ray diffraction, scanning electron microscopy, and $M{\ddot{o}}ssbauer$ spectroscopy. The formation of spinel phase without any impurity peak was identified by X-ray diffraction of all the samples. Moreover, the estimated crystallite size by X-ray line broadening indicates a decrease with increasing Zn content. This result was in agreement with the scanning electron microscopy result, indicating the reduction in grain growth with further zinc substitution. The room-temperature $M{\ddot{o}}ssbauer$ spectra show that the hyperfine fields at both the A and B sites decreased with increasing Zn content; however, the rate of reduction is not the same for different sites. Moreover, the best fit parameter showed that the quadrupole splitting values of B site increased from the pure nickel ferrite to the sample with x = 0.8.

• 폴리머
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• 제26권4호
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• pp.508-515
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• 2002

폴리프로필렌 (PP)의 전자선 가교 발포 공정에 있어서 전자선 조사량과 발포재료의 분자량 및 다양한 발포 공정이 발포체의 구조에 미치는 영향에 관해 연구하였다. 가교된 PP의 겔분율은 3.2 Mrad의 전자선 조사량에서 48%로 가장 높게 나타났고 발포체의 셀 균일성과 열 안정성에 큰 영향을 나타내었다. 3.2 Mrad 이상의 전자선 조사량에서 겔분율이 48%에서 더 이상 증가하지 않았으며, 발포체 구조 향상에도 더 이상 영향을 미치지 못하였다. 분자량이 증가할수록 높은 전단 점도와 겔분율을 나타내며 보다 균일하고 미세한 셀 구조를 형성하고, 열안정성이 높은 발포체를 형성하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.9-9
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• 2008

Recently, the thickness of solar cell gets thinner to reduce the quantity of silicon. And the reduced thickness make it easy to be broken while PV module fabrication process. This phenomenon might make PV module's maximum power and durability down. So, when using thin solar cell for PV module fabrication, it is needed to optimize the material and fabrication condition which is quite different from normal thick solar cell process. Normally, gel-content of EVA sheet should be higher than 80% so PV module has long term durability. But high gel-content characteristic might cause micro-crack on solar cell. In this experiment, we fabricated several specimen by varying curing temperature and time condition. And from the gel-content measurement, we figure the best fabrication condition. Also we examine the crack generation phenomenon during experiment.