• 한국식품저장유통학회지
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• 제19권2호
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• pp.216-222
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• 2012

옥수수 전분의 인산화 가교반응에 의한 RS4 제조 시 최적 annealing 조건을 검토하였다. 전분유에 NaOH를 0.9%, 1.2%, 1.5%/st.ds의 농도가 되게 첨가하고 복합인산염(STMP/STPP 혼합)을 이용하여 인산화 가교반응 할 경우 NaOH 농도가 높을수록 반응 초기에 RS 함량이 빠르게 증가되었으나 NaOH 농도에 상관없이 반응 12시간 후에는 비슷한 RS 함량을 나타내었다. 전분유의 Annealing 처리는 인산화 가교반응 전에 실시하였다. 전분유를 pH 2-10, 온도 $40-60^{\circ}C$, 0-14시간으로 처리한 후 인산화 가교반응을 하였다. Annealing 처리시 pH가 낮을수록 RS 함량이 높아지는 결과를 보였으며 pH 2에서 annealing 온도 $50^{\circ}C$, 2시간 annealing에서 최고의 RS 함량을 나타내었다. 따라서 최적 인산화 가교반응 조건은 먼저 pH 2.0, $50^{\circ}C$에서 2시간 annealing 처리를 한 후 황산나트륨 농도 10%/st.ds, NaOH 농도 1.2%/st.ds 조건에서 12시간 인산화 가교반응을 행하는 것으로 생각된다. RS 함량은 인산염 투입량이 증가함에 따라 직선적으로 증가하였다. 본 연구결과에 의한 최적조건을 활용하여 복합인산염 10%/st.ds의 농도로 RS4를 제조한 결과 RS 함량은 72.3% 였으며 인의 함량은 0.36%/st.ds로 한국 식품첨가물 공전에 적합하여 식품용 소재로 활용이 가능할 것으로 사료된다.

• 한국세라믹학회지
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• 제38권9호
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• pp.860-865
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• 2001

본 논문은 출발물로서 2mol% CdO가 치환된 $0.05Pb(Mn_{1/3}Sb_{2/3})O_3-0.95Pb(Zr_{0.52}Ti_{0.48})O_3$ 분말을 제조 후, 닥터 블레이드 방법으로 green sheet를 제조하기 위한 slurry의 최적 공정첨가제 조성에 관한 연구를 수행하였다. 또한, 제조된 green sheet에 대하여 소결 특성과 두께 변환에 따른 유전 및 압전 특성을 관찰하였다. 공정첨가제의 첨가에 따른 점도거동을 통하여 slurry를 최적화하였고, TGA 분석으로 소결조건을 정하였으며, sheet의 특성에 미세구조와 XRD 등으로 측정하였다. 최적의 slurry는 고형분량 30vol%에 대해 분산제 3.0wt%에서 가장 안정화되었고, 이후 바인더/가소제(0.75/0.25) 3.0wt% 첨가시 점도는 7.55Pa${\cdot}$s이었다. Green sheet의 유전 및 압전 특성들은 각각 900$^{\circ}$C, 950$^{\circ}$C, 1000$^{\circ}$C로 소결온도를 증가함에 따라 다소 증가하였지만, 두께에 따른 특성들은 큰 변화가 관찰되지 않음을 확인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.110-112
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• 2006

Membrane electrode assembly (MEA) for polymer electrolyte fuel cell (PEFC) are commonly prepared in the research laboratory by spraying, screen-printing and brushing catalyst slurry onto membrane or other support material like carbon paper or polyimide film in a batch style. These hand applications of the catalyst slurry are painstaking process with respect to precision of catalyst loading and reproducibility. It has been generally mentioned that the adoption of continuous process is very helpful to develop the reliable product. In the present work, we report the results of using continuous type coater with doctor-blade to coat catalyst slurry for preparing the MEA catalyst layers In a faster and highly reproducible fashion. We show that while expectedly faster than batch style, the machine coater requires the use of slurry of appropriate composition and a properly selected transfer decal material in order to achieve superior MEA plat lnw loading reproducibility. To make highly viscous catalyst slurry that is imperative for using coater, we use 40wt.% Nafion solution and minimize the content of organic solvent. And the choice of proper high surface area catalyst is important in the viewpoint of making well-dispersed slurry. After catalyst coating onto the support material, we transferred the catalyst layer to both sides of Nafion membrane by hot-pressing In this case, the degree of transfer was Influenced by hot-pressing condition including temperature, pressure, and time. To compare the transferring ability, we compared so many films and detaching papers. And among the support, polyethylene terephthalate(PET) film shows the prominent result.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.175-182
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• 1996

This paper deals with the properties of water permeability and porosity of cement mortar substrate coated with siliceous slurry coating under the exposure environment. Conditions of exposure enviornment are four kinds of in constant temperature water and humidity box, in indoor and outdoor exposure. Coated mortar substrate was expected continually increase in water and humidity condition, but was not in dry condition. Watertightness effect of siliceous coating was better in the condition of humidity then the dry condition, and the pore volume was decreased in that condition.

• 한국세라믹학회지
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• 제40권2호
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• pp.167-171
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• 2003

기계적 방법으로 합성된 CeO$_2$분말을 연마입자로 하여 STI용 CMP 슬러리를 제조하였다. 연마입자는 정전기적 방법과 입체적 방법으로 수계에서 안정화시킬 수 있었으며, 장기 안정성을 위해서는 입체적 방법에 의한 안정화가 유효하였다. 50$0^{\circ}C$와 $700^{\circ}C$에서 합성된 CeO$_2$를 이용하여 CMP 슬러리를 제조하고, SiO$_2$와 Si$_3$N$_4$가 블랭킷 형태로 증착된 웨이퍼를 연마한 결과 연마능률과 선택비는 연마입자의 합성조건과 분산 안정성, 슬러리의 pH 등에 의해 영향을 받았다.

• 한국입자에어로졸학회지
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• 제5권4호
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• pp.189-197
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• 2009

Wet-type particulate removal system is employed in most of ironmaking processes. These de-dusting systems require additional downstream aggregates for treatment of water and for drying of the collected slurry. Thus dried slurry can be pressed in shape of briquettes and recycled in the steelmaking process. Different from the wet-type, the dry-type particulate removal systems generate no slurry. A high-temperature, high-pressure de-dusting system with inertial inlet was developed. The target application of this system was to remove particulate matter generated from the novel ironmaking process and other steelmaking processes. In this study we conducted tests with this newly developed system to evaluate the performance of the silica-carbide (SiC) ceramic filters. In addition, for purpose of comparison, we also conducted tests with a unit which has conventional direct inlet. Fe-Particles collected from the novel ironmaking process were used in our tests as test dusts. The temperature and the pressure were kept constant at their respective values $800^{\circ}C$ and $3kg_f/cm^2$.

• 한국재료학회지
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• 제12권9호
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• pp.691-695
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• 2002

A low temperature anode-supported tubular solid oxide fuel cell was developed. The anode-supported tube was fabricated using extrusion process. Then the electrolyte layer and the cathode layer were coated onto the anode tube by slurry dipping process, subsequently. The anode tube and electrolyte were co-fired at $140^{\circ}C$, and the cathode was sintered at $1200^{\circ}C$. The thickness and gas permeability of the electrolyte depended on the number of coating and the slurry concentration. Anode-supported tube was satisfied with SOFC requirements, related to electrical conductivity, pore structure, and gas diffusion limitations. At operating temperature of $800^{\circ}C$, open circuit voltage of the cell with gastight and dense electrolyte layer was 1.1 V and the cell showed a good performance of 450 mW/$\textrm{cm}^2$.

• 한국주조공학회지
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• 제25권6호
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• pp.254-258
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• 2005

Semisolid process is possible in any material system possessing a freezing range where the microstructure should consist of the nondendritic globular solid phase separated and enclosed by the liquid phase, referred to as semisolid slurry. There are two primary semisolid processing routes, thixocasting and rheocasting. Especially, rheocasting process has become a new focus in the field of semisolid process because of its many advantages such as no special billet required and possibility of in-house scrap recycling, compared with the thixocasting process. In-Ladle direct thermal control (DTC) rheocasting has been developed, based on the fact that there is slurry and mush transition in every molten metal and the transition, which normally occurs in the range of liquid traction of 0.1 to 0.6, could be controlled by controlling solid shape and relative solid-liquid interfacial energy. In this study, A356 Al alloy was investigated to verify In-Ladle DTC rheocasting for obtaining semisolid slurry. Modeling of heat transfer was carried out to investigate the effect of pouring temperature and ladle material, geometry and temperature and the simulation results were compared with the actual experiments.

• 한국세라믹학회지
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• 제39권4호
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• pp.327-335
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• 2002

Experiments were conducted to investigate the synthesis characteristics of Precipitated Calcium Carbonate(for short PCC) in Ca(OH)$_2-CO_2-H_2O$ system by the continuous drop method of Ca(OH)$_2$ slurry into the solution containing $CO_2$(aq). When the flow rate of $CO_2$(g) increases and the concentration of Ca(OH)$_2$ slurry become low, the absorption rate of $CO_2$(g) become faster than the dissolution rate of Ca(OH)$_2$. Consequently, the growth of the calcite crystal plane is facilitated resulting in synthesis of $1.0{\mu}m$ of rhombohedral calcite. On the other hand, when the flow rate of $CO_2$(g) decreases and the concentration of Ca(OH)$_2-CO_2-H_2O$ slurry become high, new nuclei is created along with the crystal growth resulting in synthesis of $0.1{\mu}m$ of prismatic calcite. Maintaining 1.0wt% of Ca(OH)$_2-CO_2-H_2O$ slurry, 120 drops/min of drop rate and $25^{circ}C$ of temperature, the shape of PCC shows colloidal and spherical agglomerate at 100 mL/min of the flow rate of $CO_2$(g); the mixture of rhombohedral and plate-shaped calcite, at 200∼500 mL/min. Therefore, as the flow rate of $CO_2$(g) increases, the shape of PCC changes from colloidal and rhombohedral calcite to plate-shaped calcite. Maintaining 500 mL/min of the flow rate of $CO_2$(g), 120 drops/min of the drop rate of Ca(OH)$_2$ slurry, and $25^{circ}C$ of temperature, the shape of PCC shows the plate-shaped calcite at 1.0∼3.0 wt% of Ca(OH)$_2$ slurry; the hexagonal plate-shape calcite of the thickness of $0.1{\mu}m$ and the width of $1.0{\mu}m$, at 4.0 wt%.

• 한국분말재료학회지
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• 제12권3호
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• pp.192-200
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• 2005

Ultrafine copper powder was prepared from $CuO-H_2O$ slurry with hydrazine, a reductant, under $70^{\circ}C$. The influence of various reaction parameters such as temperature, reaction time, molar ratio of $N_2H_4$, PvP and NaOH to Cu in aqueous solution had been studied on the morphology and powder phase of Cu powders obtained. The production ratio of Cu from CuO was increased with the ratio of $N_2H_4/Cu$ and the temperature. When the ratio of $N_2H_4/Cu$ was higher than 2.5 and the temperature was higher than $60^{\circ}C$, CuO was completely reduced into Cu within 40 min. The crystalline size of Cu obtained became fine as the temperature increase, whereas the aggregation degree of particles was increased with the reaction time. The morphology of Cu powder depended on that of the precursor of CuO and processing conditions. The average particle size was about $0.5{\mu}m$.