• 한국분말재료학회지
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• 제22권5호
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• pp.362-366
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• 2015

The effect of sublimable vehicle composition in the camphor-naphthalene system on the pore structure of porous Cu-Ni alloy is investigated. The CuO-NiO mixed slurries with hypoeutectic, eutectic and hypereutectic compositions are frozen into a mold at $-25^{\circ}C$. Pores are generated by sublimation of the vehicles at room temperature. After hydrogen reduction at $300^{\circ}C$ and sintering at $850^{\circ}C$ for 1 h, the green body of CuO-NiO is completely converted to porous Cu-Ni alloy with various pore structures. The sintered samples show large pores which are aligned parallel to the sublimable vehicle growth direction. The pore size and porosity decrease with increase in powder content due to the degree of powder rearrangement in slurry. In the hypoeutectic composition slurry, small pores with dendritic morphology are observed in the sintered Cu-Ni, whereas the specimen of hypereutectic composition shows pore structure of plate shape. The change of pore structure is explained by growth behavior of primary camphor and naphthalene crystals during solidification of camphor-naphthalene alloys.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.56.2-56.2
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• 2012

Clinically-favored materials for bone regeneration are mainly based on bioceramics due to their chemical similarity to the mineral phase of bone. A successful scaffold in bone regeneration should have a 3D interconnected pore structure with the proper biodegradability, biocompatibility, bioactivity, and mechanical property. The pore architecture and mechanical properties mainly dependent on the fabrication process. Bioceramics scaffolds are fabricated by polymer sponge method, freeze drying, and melt molding process in general. However, these typical processes have some shortcomings in both the structure and interconnectivity of pores and in controlling the mechanical stability. To overcome this limitation, the rapid prototyping (RP) technique have newly proposed. Researchers have suggested RP system in fabricating bioceramics scaffolds for bone tissue regeneration using selective laser sintering, powder printing with an organic binder to form green bodies prior to sintering. Meanwhile, sintering process in high temperature leads to bad cost performance, unexpected crystallization, unstable mechanical property, and low bio-functional performance. The development of RP process without high thermal treatment is especially important to enhance biofunctional performance of scaffold. The purpose of this study is development of new process to fabricate ceramic scaffold at room temperature. The structural properties of the scaffolds were analyzed by XRD, FE-SEM and TEM studies. The biological performance of the scaffolds was also evaluated by monitoring the cellular activity.

• 한국염색가공학회지
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• 제21권3호
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• pp.10-18
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• 2009

Dyeing process of the natural indigo powder onto ramie and silk fabrics was investigated by using glucose and calcium hydroxide as a reducing system. Effect of reduction and dyeing conditions such as temperature and time of reduction/dyeing, and concentrations of glucose and calcium hydroxide on the dyeing process were explored. Indigo powder was obtained by drying the conventional niram paste in an oven at $50^{\circ}C$. Color strength of the dyed fabrics was evaluated by K/S value measured at the wavelength of maximum absorption(${\lamda}$max). Munsell color coordinates(H V/C) were used to compare fabric colors of ramie and silk. Ramie fabric showed purple-blue color for all the temperature and time. On the contrary, silk fabric showed wide range of color including brown, brown-green, green at the different temperature. With the increase of K/S value, the coordinate of value(lightness) decreased for both of ramie and silk fabrics. The coordinate of hue(shade) changed drastically with the increase of K/S value for silk fabric, compared with that of ramie fabric which showed nearly constant value at the whole range of K/S value. Optimum concentrations of calcium hydroxide were for 6 g/L for ramie and 4 g/L for silk at $60^{\circ}C$ and 50 min. K/S value increased with the indigo concentration. Maximum K/S value was shown at $10{\sim}12$ g/L of glucose concentration. For both of ramie and silk fabrics, the colorfastness of washing and light was lower than that of rubbing. All the colorfastness values were improved with the increase of color strength.

• 한국세라믹학회지
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• 제36권2호
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• pp.178-185
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• 1999

Si3N4 겔캐스팅공정 제어를 위하여, 슬립 조성의 영향이 슬립의 점성특성과 성형체의 기계적 특성 및 소결체의 밀도에 미치는 영향에 대하여 조사하였다. 아크릴아마이드 모노머, 고분자전해질, 그리고 질화규소의 혼합물을 어트리터에 예비혼합한 후 볼밀링하여 슬립을 제조하였다. 개시제가 혼합된 슬립을 진공탈포하고 몰드에 주입하고 중합을 진행하였으며, 겔화된 슬립을 건조하여 성형체를 얻었다. 슬립의 특성과 성형체의 기계적 특성을 평가하기 위해, 슬립의 점도 측정과 직경방향 압축시험을 행하였다. 그 결과, near net shaping을 위한 낮은 점도를 갖는 46 vol%의 고농도 질화규소 슬립의 제조가 가능하였다. 성형체가 기계적 특성은 주로 모노머의 농도에 비례하여 증가하였다. 또한, 겔캐스트 성형체의 인장강도가 약 3MPa이 넘으면 기계적 가공이 가능하였으며, 겔캐스팅 성형체를 176$0^{\circ}C$, 3시간 상압소결하여 약 98.5%의 상대밀도를 얻을 수 있었다.

• 한국가구학회지
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• 제24권4호
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• pp.345-349
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• 2013

Yellow poplar is well known commercial hardwood species in the world because of its availability, rapid growth, large size, excellent form, early natural pruning, and the good working quality of the wood. Therefore, yellow poplar (Liriodendron tulipifera L.) has been adopted in South Korea for decades ago, and its cultivating the saplings and silvicultural system have been studied. However, yellow poplar is still embroiled in controversy for utilization of use and worth. This species has not only advantages such as lower weight, light color, and higher machinability and bending processing, but also has disadvantages which are bad smell and different colors on heartwood and sapwood. In this study, the objective was that use of yellow poplar board as furniture materials by drying and painting process. Thirty years old yellow poplar was cut and dried for 7 days by high-frequency dryness. Adjustment of color tone to walnut color was conducted with multiple colorants and various number of spread times. Uniform color of yellow poplar on heartwood and sapwood was accomplished by applying 1 time stain (green), 2 times transparent primer, 1 time middle-painting (walnut), and 2 times top-painting (walnut) in sequentially. The painted yellow poplar board was used to manufacture table and dressing table. During the furniture manufacture process, no critical issues were occurred on part of jointing and painting. This painting method may be useful data for future use of yellow poplar as furniture materials.

• 한국작물학회지
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• 제26권2호
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• pp.147-156
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• 1981

벼를 곡립함수율(습양기준) 28～20%인 시기에 예취하고 논에서 곡립함수율 17% 정도까지 일시 건조한 후에 탈곡하고 정조를 곡립함수율 14～15%까지 재건조한 후 유통 또는 저장하는 일반적인 우리나라 관행 수확조제체계에서는 정조 수확손실이 크고 완전미수율이 떨어지기 쉬워 그 개선이 요구되는 바, 국내에서 최근에 작물 수확전 처리 건조제로 등록 사용허가된 diquat의 효용성과 문제점을 밝히기 위해 본 연구를 수행하였다. 공시품종은 인.일형 품종 수원 26004와 밀양2003, 일본형 품종 진흥이었고, diquat의 처리시기와 처리량이 곡립함수율, 정조천발중, 벼알탈입성, 제책율 및 정백률과 동할미율, 수미율, 심복백미율, 청미율, 색택 및 냄새 등 품종에 미치는 영향을 조사하였으며 그 결과는 다음과 같이 요약된다. 1. Diquat의 수확전처리 벼 건조효과는 인.일형품종들에서는 뚜렷하나 일본형 품종에서는 무처리구와 통계적 유의차가 없었다. 2. 인.일형 품종들에 대한 처리적기는 벼의 생리적, 성숙기 2일전~3일후의 기간이었고, 처리기량은 diquation 336g/ha (diquat dibromide 20% 함유한 상품 Region 액제 300cc/10a) 수준이었으며, 처리적기에 적량을 살포할 경우 수확기의 곡입을 함수율은 15~16%로써 무처리구 20～24%에 비하여 5～8%의 건조효과가 있었고 예취와 탈곡작업을 연속적으로 실시할 수 있는 수분조건이었다. 3. Diquat을 처리하면 벼알의 탈립성은 무처리구에 비하여 10～15% 정도 감소되었다. 4. Diquat을 적기에 철포하면 정조수량, 제해율 및 정백률에 영향하지 않았다. 5. Diquat 처리는 동할미, 수미 및 심복백미율에는 영향하지 않고 청미율은 현저히 감소시켜 품종을 향상시켰다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.131.1-131.1
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• 2010

This study was conducted for engineering optimization for the gasification process which is the key factor for success of Taean IGCC gasification plant which has been driven forward under the government support in order to expand to supply new and renewable energy and diminish the burden of the responsibility for the reduction of the green house gas emission. The gasification process consists of coal milling and drying, pressurization and feeding, gasification, quenching and HP syngas cooling, slag removal system, dry flyash removal system, wet scrubbing system, and primary water treatment system. The configuration optimization is essential for the high efficiency and the cost saving. For this purpose, it was designed to have syngas cooler to recover the sensible heat as much as possible from the hot syngas produced from the gasifier which is the dry-feeding and entrained bed slagging type and also applied with the oxygen combustion and the first stage cylindrical upward gas flow. The pressure condition inside of the gasifier is around 40~45Mpg and the temperature condition is up to $1500{\sim}1700^{\circ}C$. It was designed for about 70% out of fly ash to be drained out throughout the quenching water in the bottom part of the gasifier as a type of molten slag flowing down on the membrane wall and finally become a byproduct over the slag removal system. The flyash removal system to capture solid particulates is applied with HPHT ceramic candle filter to stand up against the high pressure and temperature. When it comes to the residual tiny particles after the flyash removal system, wet scurbbing system is applied to finally clean up the solids. The washed-up syngas through the wet scrubber will keep around $130{\sim}135^{\circ}C$, 40~42Mpg and 250 ppmv of hydrochloric acid(HCl) and hydrofluoric acid(HF) at maximum and it is turned over to the gas treatment system for removing toxic gases out of the syngas to comply with the conditions requested from the gas turbine. The result of this study will be utilized to the detailed engineering, procurement and manufacturing of equipments, and construction for the Taean IGCC plant and furthermore it is the baseline technology applicable for the poly-generation such as coal gasification(SNG) and liquefaction(CTL) to reinforce national energy security and create new business models.

• Journal of Pharmaceutical Investigation
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• 제31권4호
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• pp.241-256
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• 2001

Alginate microspheres, containing fluorescein isothiocyanate-bovine serum albumin (FITC-BSA) or green fluorescent protein (GFP) were prepared and used as a model drug to develop the oral vaccine delivery system. The alginate microspheres were coated with poly-L-lysine or chitosan. Two methods, w/o-emulsion and spray, were used to prepare alginate microspheres. To optimize preparation conditions, effects of several factors on the particle size and particle morphology of microsphere, and loading efficiency of model antigen were investigated. In both preparation methods, the particle size and the loading efficiency were enhanced when the concentration of sodium alginate increased. In the w/o-emulsion preparation method, as the concentration of Span 80 was increased from 0.5% to 2%, the particle size was decreased, but the loading efficiency was increased. The higher the emulsification speed was, the smaller the particle size and loading efficiency were. The concentration of calcium chloride did not show any effect on the particle size and loading efficiency. In the spray preparation method, the particle size was increased as the nozzle pressure $(from\;1\;kgf/m^2\;to\;3\;kgf/m^2)$ and spray rate was raised. Increasing calcium chloride concentration (<7%) decreased the particle size, in contrast to no effect of calcium chloride concentration on the w/o-emulsion preparation method. Alginate microspheres prepared by two methods were different in the particle size and loading efficiency, the particle size of microspheres prepared by the spray method was about $2-6\;{\mu}m$, larger than that prepared by the w/o emulsion method $(about\;2{\mu}m)$, and the loading efficiency was also higher with spray method. Furthermore, drying process for the microspheres prepared by the spray was simpler and easier, compared with the w/o emulsion preparation. Therefore, the spray method was chosen to prepare alginate microspheres for further experiments. Release pattern of FITC-BSA in alginate microspheres was evaluated in simulated intestinal fluid and PBS (phosphate buffered saline). Dissolution rate of FITC-BSA from alginate/chitosan microsphere was lower than that from alginate microsphere and alginate/poly-L-lysine microsphere. By confocal laser scanning microscope, it was revealed that alginate/FITC-poly-L-lysine microspheres were present in close apposition epithelium of the Peyer's patches of rabbits following inoculation into lumen of intestine, which proved that microspheres could be taken up by Peyer's patch. In conclusion, it is suggested that alginate microsphere prepared by spray method, showing a particle size of & $10\;{\mu}m$ and a high loading efficiency, can be used as a model drug for the development of oral vaccine delivery system.

• 한국습지학회지
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• 제13권2호
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• pp.231-242
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• 2011

도시화가 진행될수록 건물의 옥상 및 교통관련 시설물 또한 증가하여, 녹지공간은 감소하고 불투수면은 증가하게 된다. 불투수면이 증가함에 따라, 도시내 자연적 물순환 시스템 파괴, 비점오염물질 증가, 생태축 단절 등과 같은 다양한 환경수리학적 문제점이 발생되고 있다. 최근 들어 국민들의 생활 및 의식수준이 향상되면서, 도시의 경제적인 측면뿐만 아니라 심미적인 측면, 환경적인 측면을 동시에 고려한 지속가능한 도시 개발이 요구되고 있다. 또한 강우유출수 관리에 대한 관심과 인식이 높아지면서 Low Impact Development(LID) 관련 기술의 개발 및 적용에 관한 연구가 활발히 진행되고 있으나, 국내 환경에 적합한 가이드라인, 설계기준 등은 매우 부족한 실정이다. 본 연구는 도시 및 도로가에 적용하기 위한 소규모 인공습지 기술을 개발하기 위하여, Pilot-scale 실험을 실시하였으며, 분석 결과, TSS, $COD_{Cr}$, TN, TP, Total Pb에 대한 평균저감효율이 각각 95%, 82%, 35%, 91%, 57%로 나타났다. 이러한 결과는 소규모 인공습지가 향후 도시 내 효율적인 물순환 시스템을 구축하고, 수생태계 보전에 기여할 수 있을 것으로 판단된다.

• 한국조경학회지
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• 제42권4호
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• pp.76-88
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• 2014

본 연구의 목적은 농어업유산과 경관의 관계 규명을 통하여 농어업유산의 경관특성요소를 도출하고, 이를 바탕으로 한국농어업유산 제1호로 지정받았으며, 국내에서는 처음으로 세계중요농업유산(GIAHS)에 등재된 청산도의 경관특성요소를 유형화한 후, 이에 대하여 방문객들이 중요시 여기는 인자와 만족하는 인자 간의 차이를 파악함으로써, 한국농어업유산으로 지정된 청산도의 경관 보존 및 관리를 위한 우선순위를 제시하는 것이다. 이를 위하여 농어업유산과 경관의 관계 규명 및 농어업유산의 경관특성요소 도출을 위한 문헌고찰, 청산도의 경관특성 요소를 도출하기 위한 현장답사, 청산도의 경관특성요소에 대한 중요도-만족도 설문조사를 실시하였고, SPSS 20.0을 활용하여 신뢰도분석, 기술통계분석, IPA 분석을 실시하였으며, 그 결과는 다음과 같다. 1사분면에 분포하여 지속적 노력을 요하는 인자는 유채꽃밭, 바다, 청보리밭, 구들장논, 방파제와 등대, 전복양식장, 돌집, 초가집, 해안도로, 슬로길, 성서마을 돌담길, 주민농업행위로 분석되었다. 2사분면에 분포하여 집중적 관리전략이 필요한 인자로는 주변산지, 선착장, 도청항, 선박들, 수산물시장, 독살이돌담, 원색지붕농가, 느린섬여행학교, 펜션과 카페, 버스정류장, 정자목, 횟집거리, 해수욕장, 촬영지로 분석되었다. 3사분면에 분포하여 관리 조절이 필요한 인자는 소나무숲, 해변, 갯벌, 마늘밭, 비닐하우스, 곡식건조장, 미역 건조장, 문화유산전시장, 초분, 당리굿, 장터, 주민어업행위, 주민산업행위, 주민일상행위, 선착장 방문 행위, 슬로길 산책 행위, 특산물 섭취 쇼핑 행위, 농어업 체험 행위로 분석되었다. 4사분면에 분포하여 과잉 노력으로 분석된 요인은 도출되지 않았다.