• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.893-895
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• 2009

In this paper, we described the unique and novel method to prepare two kinds of electro-active particles, black and white particles with different polarity. The surface of the particles was characterized to be uniform and clean by adopting spray dryer as a tool for genesis of particles; neither surfactants nor high dielectric medium like water was employed during particle preparation step. The other purpose of this study is to investigate the factors that contribute high driving voltage of particlebased display like QR-LPD. We extracted parameters interaction between particle and electrode, and between oppositely charged particles. Here we reported an excellent behavior of particle-based display that showed low operating voltage, high contrast ratio as high as 8:1 without scarification of quick response time. By optimizing the particle size, charge per mass, selection of external additive sets, a lower driving voltage as low as 40V for the particles with $10{\mu}m$ volume average diameter was obtained.

• 공업화학
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• 제7권6호
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• pp.1147-1155
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• 1996

Wheel형 분무건조기에서 식품첨가제로 사용되는 치즈분말의 건조공정을 반응표면법에 의하여 원료의 고형분함량, wheel 회전속도 및 출구온도를 독립변수로 하고 분말제품의 수분함량, 겉보기밀도, 분말 입자크기 및 현탁액의 점도를 종속변수로 하여 중심합성계획법에 따라 분산분석한 후 유의성과 상관관계를 검증하였다. 독립변수와 종속변수들의 상관관계를 검증한 결과 입자크기와 수분함량은 wheel의 회전속도가 커질수록 감소하였고, 겉보기밀도는 출구온도가 높아짐에 따라 감소하였다. 현탁액의 점도는 wheel의 회전속도와 고형분함량이 커짐에 따라 증가하였다. 분말제품의 종속변수들의 상관관계에서 수분함량과 겉보기밀도는 비례 관계, 입자크기는 수분함량과 겉보기밀도와 반비례의 관계를 나타내었다.

• 한국기후변화학회지
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• 제2권2호
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• pp.107-113
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• 2011

본 연구에서는 하동화력 0.5 MW 건식 이산화탄소 포집 공정에 적용하고 있는 Potassium 계열 흡수제의 성능 개선을 위한 실험 결과를 기술하였다. 먼저, 마그네타이트와 산화구리를 additive로 적용한 흡수제 2종을 각각 분무건조기를 이용하여 제조한 흡수제의 재생성을 포함한 물성을 평가하였다. 그 결과, 마그네타이트를 적용한 흡수제의 내마모도가 상대적으로 우수한 특성을 나타내었다. 두 번째는, 마그네타이트를 적용한 개량형 Potassium계 흡수제의 연속적인 흡수/재생 특성을 파악하기 위하여 Multi cycle TGA 반응성 평가를 수행하였다. 그 결과, 2nd cycle 이후에도 5.5 wt% 이상의 $CO_2$ 흡수능을 유지하였으며, 내마모도 값도 0.5 정도로 아주 우수하였다. 마지막으로, 공정상의 재생 온도를 낮출 수 있는 조성 선정을 위하여 supporter의 특성이 다른 흡수제의 특성을 고찰하였다. 그 결과, 염기성 지지체를 적용한 KMO 흡수제의 흡수능이 7.2 wt%로 높게 나타났다.

• Archives of Pharmacal Research
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• 제23권1호
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• pp.66-71
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• 2000

Peonjahwan, an oriental traditional medicine composed of crude herbal drugs and animal tissues is bitter and poorly water-soluble. To mask the bitterness of peonjahwan and enhance the release of bilirubin, one of the crude active ingredients of peonjahwan, peonja dry elixir (PDE), was prepared using a spray-dryer after extracting the crude materials in ethanol-water solution. coated peonja dry elixir (CPDE) was then prepared by coating the PDE with Eudragit acrylic resin. Panel assessed bitterness and release test of bilirubin from PDE and CPDE were carried out and compared with peonjahwan alone. PDE was found to have little effect upon the reduction of the bitterness of peonjahwan. However, the bitterness of CPDE was found to reduce to 1/4 of that of peonjahwan due to the encapsulation of crude active ingredients by the dextrin and Eudragit shell (P<0.05). The release rate of bilirubin from PDE and CPDE for 60 min increased about 3.5- and 2.5-fold, respectively, compared to peonjahwan at pH 1.2. It is concluded that CPDE, which masked the bitterness of peonjahwan and enhanced the release of bilirubin, is a preferable delivery system for peonjahwan.

• 한국세라믹학회지
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• 제53권1호
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• pp.13-17
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• 2016

It is highlighted that increasing the adsorbent surface area on volumetric basis is very important in providing an easy access for gas molecules. Fine particles around $3{\mu}m$ of soft-burned dolomite kiln dust (SB-DKD) were hydrated to wet slurry samples by ball mill process and then placed in a chamber to use spray dryer method. Spherical granules with particle size distribution of $50{\sim}60{\mu}m$ were prepared under the experimental condition with or without addition of a pore-forming agent. The relationship between bead size of the pore-forming agent and size of SB-DKD particles is the most significant factor in preparation of spherical granules with a high porosity. Whereas addition of smaller beads than SB-DKD resulted in almost no change in the surface porosity of spherical granules, addition of larger beads than SB-DKD contributed to obtaining of the particles with both 15 times larger average pore volume and 1 order of magnitude larger porosity. It is considered that spherical granules with improved $N_2$ gas adsorption ability may also be utilized for other atmospheric gas adsorption.

• 한국세라믹학회지
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• 제39권1호
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• pp.51-56
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• 2002

고순도 알루미나 분말에 소결조제로서 초산 마그네슘과 질산 마그네슘을 1000ppm첨가하여 제작한 소결체에 대해서 소결조제로 사용한 MgO의 출발물질의 종류가 소결체 특성에 미치는 영향을 고찰하였다. 초산 마그네슘과 질산 마그네슘을 사용해서 제작한 소결체에 대해서 소결온도 1$600^{\circ}C$에서 상대밀도의 급격한 감소가 확인되었고 SEM관찰결과 소결조제로 사용한 두 종류의 출발물질을 첨가한 경우에 동일하게 소결체의 outer layer에서는 입성장 및 기공이 형성되어있고 inner layer에서는 알루미나 입계에 제2상의 존재가 관찰되었다. 이 시편의 EPMA을 이용한 원소분석결과로부터 소결온도 1$600^{\circ}C$에서 알루미나 입계에 존재하는 제2상은 Mg를 함유한 혼합물이라는 것을 알 수 있었다.

• 대한가정학회지
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• 제41권2호
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• pp.107-121
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• 2003

This study was discussed the dyeing of wool and nylon fabrics with Chinese Scholar Tree extract. The extracts of Chinese Scholar Tree was prepared in the condition of heating at $95{\pm}5C$, for 1 hour and cooling to 40C. And then the extracts of color matter treate with vacuum concentration at $60{\pm}2^{\circ}C$, 30mmHg and dried with spray dryer. The dyeing of wool and nylon fabric in this experiment was also employed the mordant dyeing method such as pre-mordant, post-mordant and simultaneous mordant method. The mordanting agents used in this study were as followings ; aluminium potassium sulfate, copper(II) acetate monohydrate, chromium potassium sulfate$.$$7H_2O$, Tin(II) chloride dihydrate, iron(II)sulfate $7H_2O$. For an evaluation of the dyeing property of the mordanting agents, the pre-mordant method, the repeat dyeing and the fastness of the light, dry cleaning, washing and rubbing measured respectively. From the results of the dye absorption, the optimum dyeing condition of the wool and nylon fabrics with Chinese Scholar Tree extract is at 80C dyeing temperature for 60 minutes. The optimum concentration of mordanting agent is Al, Cr, Sn 1%, Fe, Cu 2% solution. In general, the fastness property of the dyed wool and nylon fabrics had a comparatively high grade.

• Journal of Pharmaceutical Investigation
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• 제41권4호
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• pp.249-253
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• 2011

To develop a sildenafil lactate-loaded solid self-emulsifying drug delivery system (SEDDS) with a fast onset of action and immediate action of erection, sildenafil lactate (0.3 g), which was prepared using a spray dryer, was dissolved in 4.7 g of the mixture of glyceryl monooleate/Transcutol/ Tween 20 (3/0.5/1, g). Its emulsion droplet size and pharmacokinetics in rabbits were evaluated compared with sildenafil citrate-loaded commercial tablet. The sildenafil lactateloaded SEDDS showed an emulsion droplet size of about 300 nm. In pharmacokinetics study, it gave significantly faster Tmax than did the commercial tablet. Thus, the sildenafil lactate-loaded SEDDS at the one-third drug dose compared to sildenafil citrate-loaded conventional tablet might induce a fast onset of action and immediate erection without enhanced bioavailability compared with the sildenafil citrate-loaded commercial tablet.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.282-282
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• 1996

The purpose of this study was to prepare the nifedipine dry elixir (NDE) and coated nifedipine dry elixir (CNDE) containing nifedipine ethanol solution for improving the dissolution rate and bioavailability of nifedipine. NDE containing nifedipine and ethanol in wall materials of dextrin was prepared using a spray-dryer and then NDE was coated with eudragit acrylic resin to make CNDE. Shape and size of the NDE and CNDE were monitored by scanning electron micrograph and laser particle size analyzer In vitro dissolution tests were performed in simulated gastric and intestinal fluid. Bioavailability of NDE and CNDE were compared with drug powder suspension and commercial soft capsule after oral administration of the preparations to rats. NDE and CNDE are spherical in shape. Cross-sectional view of dry elixirs indicates the large inter cavity containing ethanolic drug solution in shell. Geometric mean diameter of NDE and CNDE is about 6.64 and 8.70 $\mu\textrm{m}$, respectively. Drug dissolution rate within first 5 min from NDE increased dramatically irrespective of dissolution medium. However, CNDE showed a particularly retarded dissolution rate in pH 1.2 simulated gastric fluid compared with NDE. The bioavailability of nifedipine in the NDE was increased dramatically compared with drug powder suspension. CNDE reduced initial burst-out plasma peak compared with NDE. CNDE as a sustained release delivery system could reduce the initial burst-out plasma peak due to controlling the release rate of nifedipine from NDE and maintain the effective plasma level over a longer period within therapeutic window with enhanced bioavailability of nifedipine.

• 한국세라믹학회지
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• 제38권5호
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• pp.479-484
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• 2001

고순도 알루미나 분말에 소결조제로서 MgO를 0ppm 및 500ppm 첨가하여 열분무건조기를 사용하여 준비한 과립을 80$0^{\circ}C$에서 하소를 함으로써 얻어진 과립으로 제작한 소결체의 MgO 첨가량에 따른 미세구조와 꺾임강도에 미치는 영향을 고찰하였다. 또한 시편두께를 50$mu extrm{m}$의 박편으로 가공하여 투광법으로 내부구조도 관찰하였다. MgO를 500ppm 첨가하여 제작한 과립을 180 MPa의 냉간정수압성형성 후 1$600^{\circ}C$에서 소결한 소결체는 상대밀도가 100%에 도달하였고 균일한 결정립성장의 치밀한 미세구조를 나타내었다. MgO를 500ppm 첨가한 시편의 4점 꺾임강도 또한 각 소결온도에서 MgO를 9ppm 첨가한 시편보다 23%-32%정도 높은 강도를 나타내었으며, 특히 소결온도 1$600^{\circ}C$에서는 꺾임강도가 501MPa 그리고 weibull 계수가 20의 고강도이면서 신뢰성이 높은 알루미나 소결체가 얻어졌다. 본 연구에서는 weibull 계수의 값이 높은 시편일수록 내부구조의 결함크기가 작고 이 작은 결함이 시편내부에 균일하게 분포되어 있음을 확인할 수 있었다.