• 펄프종이기술
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• 제39권3호
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• pp.36-40
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• 2007

It has been problematic to repulp the dry broke treated with permanent wet strength agents like PAE, UF and MF. Solution type GPAM has the benefit of easy repulping but it has problems of cocross-linking and tends to gel. Therefore, the product concentration must be lower than 10% to reduce the gel generation problem. We developed emulsion type GPAM by an inverse emulsion technology to resolve both the repulping problem with permanent wet strength agents and the stability problem of GPAM solution products.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.259-264
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• 2000

Systematic research of metal alkoxide electrophoretic deposition has been developed. The formation mechanism of electrophoretic deposits has been offered. The structure study of dry and heat-treated electrophoretic deposits has been established. The concrete examples of one and bi-component oxide thin film formation were considered. The new approaches for thin film technology have developed on various substrates of different shapes and sizes. The correlation between thin film structure, mechanism of their formation, and physico-chemical properties has been determined.

• International Journal of Advanced Culture Technology
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• 제3권2호
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• pp.110-117
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• 2015

10 wt% (Ni-Co) catalysts with different Ni and Co content : 10%Ni, 9%Ni1%Co, 7%Ni3%Co, 5%Ni5%Co, 3%Ni7%Co, and 10%Co; were prepared using sol-gel method followed by incipient wetness impregnation method. To investigate the catalytic activity including the stability, dry methane reforming were demonstrated over the pelletized catalysts at $620^{\circ}C$ under atmospheric pressure in a $CH_4:CO_2:N_2$ feedstock for 360 min. The results showed that bimetallic catalysts with the Co content equal to or greater than 3% were more stable than monometallic catalysts (10%Ni and 10%Co). The temperature programmed hydrogenation interpreted that the additional of Co into Ni catalyst improved the carbon resistance from methane cracking. Promoted this type of bimetallic catalyst using 1wt% K (trimetallic catalyst) prevented the carbon formation on the catalyst. The temperature programmed desorption of $CO_2$ indicated that this trimetallic catalyst has a greater number of strong basic sites. Moreover, the appearance of K lowered the number of weak basic sites and decreased the conversion of methane by 12 %.

• 미생물학회지
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• 제50권3호
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• pp.227-232
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• 2014

본 연구에서는 bacterial cellulose를 생산하는 감귤에서 분리된 Gluconacetobacter sp. gel_SEA623-2를 이용하여 초기 초산농도 및 Lactobacillus plantarum KCCM 80077 유산균을 접종한 mixed culture가 bacterial cellulose 생산성에 미치는 영향을 알아보았다. 0.5%의 초산을 첨가한 mixed culture의 경우 초기 생균수가 $2.4{\times}10^6CFU/ml$에서 14일 동안 배양한 이후에 $1.1{\times}10^7CFU/ml$까지 증가하였고 total acidity가 0.5%의 초산을 첨가한 single culture와 비교하여 0.3% 가량 높게 측정되어 유산균에 의해 추가적으로 젖산이 생성된 것으로 판단된다. Single culture에서는 초기 초산농도가 0.0 및 0.5%일 때 1.0% 농도와 비교하여 상대적으로 높은 bacterial cellulose 생산성을 나타내기는 하였으나 유의적인 차이는 보이지 못하였다. 하지만 mixed culture에서는 0.5%의 초산을 첨가하였을 때 $37.83{\pm}6.81g/L$의 dry weight과 $10.33{\pm}0.58mm$의 thickness를 나타냄으로써 1%의 초산을 첨가한 single culture의 $28.40{\pm}1.23g/L$와 $7.50{\pm}0.50mm$의 생산량과 비교하여 유의적인 차이를 나타내었다(P<0.05).

• 한국융합학회논문지
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• 제11권5호
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• pp.241-251
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• 2020

항균, 항산화, 항염증 효능의 기능성 원료로써 효능이 확인된 느릅나무 추출물을 포함하는 화장품 개발을 위한 연구와 이 화장품의 아토피피부염과 같은 건조하고 민감한 피부 개선 효능에 대한 연구를 수행하였다. 원료 물질인 느릅나무 초임계 추출박 60%주정 추출물(USCFR)과 초임계 추출물(USCF), 이를 포함하는 예비제형 DKBP-1903 (겔)에 대한 독성시험을 수행한 결과 '무독성'으로 판정되었다. 이를 토대로 조제한 각 제형별 화장품 로션, 크림, 겔에 대한 안정성 시험 결과, 크림과 겔이 더 우수한 안정성을 보였고 안정성이 확보된 두 가지 제형에 대해 아토피 피부염 개선 효능 입증을 위한 화장품 효능시험으로 48시간 보습지속력 시험과 건조함에 의한 소양감개선 시험을 진행한 결과, 크림과 겔 도포 24시간 후 82.9%, 92.32%의 피부각질층 수분함량 개선율을 보였고 2주 후부터 소양감 개선 효과를 나타냈다. 이러한 결과를 통해 크림과 겔 모두 비교적 안전한 보습제로써 건조하고 민감한 피부에 도움을 줄 수 있는 것으로 판단된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.407.1-407.1
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• 2016

Electrochromism is defined as a phenomenon which involves persistently repeated change of optical properties between bleached state and colored state by simultaneous injection of electrons and ions, sufficient to induce an electrochemical redox process. Due to this feature, considerable progress has been made in the synthesis of electrochromic (EC) materials, improvements of EC properties in EC devices such as light shutter, smart window and variable reflectance mirrors etc. Among the variable EC materials, solid-state inorganics in particular, metal oxide semiconducting materials such as nickel oxide (NiO) have been investigated extensively. The NiO that is an anodic EC material is of special interest because of high color contrast ratio, large dynamic range and low material cost. The high performance EC devices should present the use of standard industrial production techniques to produce films with high coloration efficiency, rapid switching speed and robust reversibility. Generally, the color contrast and the optical switching speed increase drastically if high surface area is used. The structure of porous thin film provides a specific surface area and can facilitate a very short response time of the reaction between the surface and ions. The large variety of methods has been used to prepare the porous NiO thin films such as sol-gel process, chemical bath deposition and sputtering. Few studies have been reported on NiO thin films made by using sol-gel method. However, compared with dry process, wet processes that have the questions of the durability and the vestige of bleached state color limit the thin films practical use, especially when prepared by sol-gel method. In this study, we synthesis the porous NiO thin films on the fluorine doped tin oxide (FTO) glass by using sputtering and anodizing method. Also we compared electrical and optical properties of NiO thin films prepared by sol gel. The porous structure is promised to be helpful to the properties enhancement of the EC devices.

• 한국세라믹학회지
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• 제32권12호
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• pp.1357-1368
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• 1995

Nasigels of composition Na0.75Zr2PSi2O12 and Na3Zr2PSi2O12 have been synthesized by the sol-gel technique using metal alkoxide precursors. The monolithic dry gels of Na0.75Zr2PSi2O12 with no crack have been prepared by the control of the shrinkage rte, but gels of Na3Zr2PSi2O12 were impossible to prepare without cracking. The gels treated up to 80$0^{\circ}C$ led to the formtion of glass but the glasses were converted to the crystalline phases at above this temperature. Crystaline phases precipitated from the Na0.75Zr2PSi2O12 glass were NASICON-like phase, Na2Si2O5, and free Zirconia. Phase that precipitated from the Na3Zr2PSi2O12 was only rhombohedral NASICON. For Na0.75Zr2PSi2O12 gels, framework of PO4 tetrahedra and SiO4(PO4) tetrahedra formed at low temperature but changed to that of SiO4 and SiO4(PO4) tetrahedras as it were crystallized. In the case of Na3Zr2PSi2O12 gel, framework of isolated PO4 and SiO4 tetrahedras formed at low temperature but changed to SiO4(PO4) tetrahedra framework which usually formed in the NASICON crystal after crystallization at high temperature. The gels treated up to 80$0^{\circ}C$ contained the residual water. The ionic conduction was attributed to the motion of proton and Na+ ion at low (up to 150~20$0^{\circ}C$) and high temperatures, respectively. As the temperature of heat treatment increased, ionic conductivity gradaully increased with the extent of precipitation of crystalline phase.

• International Journal of Advanced Culture Technology
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• 제3권1호
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• pp.21-30
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• 2015

Ceramic foams are prepared as positive images corresponding to a plastic foam structure which exhibits high porosities (85-90%). This structure makes the ceramic foams attractive as a catalyst in a dry reforming process, because it could reduce a high pressure drop problem. This problem causes low mass and heat transfers in the process. Furthermore, the reactants would shortly contact to catalyst surface, thus low conversion could occur. Therefore, this research addressed the preparation of dry reforming catalysts using a sol-gel catalyst preparation via a polymeric sponge method. The specific objectives of this work are to investigate the effects of polymer foam structure (such as porosity, pore sizes, and cell characteristics) on a catalyst performance and to observe the influences of catalyst preparation parameters to yield a replica of the original structure of polymeric foam. To accomplish these objectives industrial waste foams, polyurethane (PU) and polyvinyl alcohol (PVA) foams, were used as a polymeric template. Results indicated that the porosity of the polyurethane and polyvinyl alcohol foams were about 99% and 97%. Their average cell sizes were approximate 200 and 50 micrometres, respectively. The cell characteristics of polymer foams exhibited the character of a high permeability material that can be able to dip with ceramic slurry, which was synthesized with various viscosities, during a catalyst preparation step. Next, morphology of ceramic foams was explored using scanning electron microscopy (SEM), and catalyst properties, such as; temperature profile of catalyst reduction, metal dispersion, and surface area, were also characterized by $H_2-TPR$ and $H_2-TPD$ techniques, and BET, respectively. From the results, it was found that metal-particle dispersion was relatively high about 5.89%, whereas the surface area of ceramic foam catalysts was $64.52m^2/g$. Finally, the catalytic behaviour toward hydrogen production through the dry reforming of methane using a fixed-bed reactor was evaluated under certain operating conditions. The approaches from this research provide a direction for further improvement of marketable environmental friendly catalyst production.

• 방사선산업학회지
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• 제6권1호
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• pp.89-94
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• 2012

Three-dimensional network hydrogels were prepared by ${\gamma}$-irradiation of aqueous solutions of poly(vinyl alcohol) (PVA) and glycerol (Gly). Oven-drying was used to measure the gel fraction (G), hydration (H) or swelling behavior (S) of the prepared hydrogels. This study made a hypothesis that hydrogen bonds due to addition of glycerol and change of dry states such as freeze-drying (FD), room-drying (RD) and oven-drying (OD) acts on the G, H, and S. Interesting results on the hydrogen bonding effect in the prepared hydrogels are monitored at different drying conditions. The FD samples have a higher G values with increase in glycerol content as compared with the OD and RD samples. The formation of strong hydrogen bonding network among Gly molecules and hydrogel matrix was considered as the main driving force, resulting in the changes in the G, H, and S of the hydrogels under different drying conditions.

• 한국식품조리과학회지
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• 제7권4호
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• pp.63-69
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• 1991

1. 이화학적 특성 1) 선화녹두의 일반성분 조성은 수분 13.19%, 지방 1.02%, 단백질 23.57%, 회분 3.13%였고 선화녹두 조전분의 일반성분 조성은 수분 12.45%, 지방0.63%, 단백질 0.94%, 회분 0.13%로 나타났다. 2) 거피시킨 녹두로부터 얻은 건조 전분(수분 12.48%)의 수율은 22.84% 이었고 이는 통 녹두로부터의 수율로 환산하면 20.35%로 도토리 전분의 수율과 비교해 볼 때 전분 함랑이 상당히 낮은 것으로 나타났다. 3) 물결합 능력은 183.1%였고 팽윤력은 온도가 높아짐에 따라 증가하는 양상인데 $70^{\circ}C$까지는 미약하게 증가하나 그 이상의 온도가 되면서 팽윤도가 현저하게 증가하였다. 또한 용해도의 변화도 팽윤도와 비슷한 양상을 보였다. 4) amylose와 amylopectin함량은 22.5%, 77.5%로 나타났고 amylograph에 의한 조전분의 호화는 8%와 10% 전분에서 모두 최고 점도가 나타났으며 농도에 따른 차이는 점성의 크기에만 나타났고 전체적인 양상은 비슷했다. 2. 기계적 검사결과 기계적 검사 결과는 8% 녹두 전분 Gel과 10% 녹두전분 Gel에서 같은 양상이었다. 지방 첨가량이 증가할수록 Hardness와 Fractuability는 감소하는 경향이었고 Elasticity, Adhesiveness, Chewiness는 증가하는 경향을 보였으며 L, a, b값도 증가하는 경향을 보임으로서 지방 함량이 증가할수록 명도는 높고 적색 및 황색에 가까와짐을 알 수 있다. 또한 $\Delta$E 값도 지방 첨가량이 많아질수록 증가하는 경향을 보였다. 이상의 결과에서 지방의 첨가는 녹두전분 Gel의 Texture에 상당한 영향을 미치는 것으로 평가되었다. 따라서 관능검사까지 실험을 확대하여 주관적 평가를 하고자 하며 기계적 특성과 관능적 특성간의 상호 관련성에 대하여 연구를 계속하고자 한다.