• Journal of Pharmaceutical Investigation
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• 제8권1호
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• pp.27-36
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• 1978

Spherical granules of anti-inflammatory enzyme were prepared by mixer granulation and the recovery rate of enzyme activity by processing was compared with tablet ones. In the enteric granule coating .processing, the effect of the amount of coating solution and the conentration of fatty alcohol on disintegration and stabilities on the accelerated conditions were also studied. Being prepared in non-pressure and non-aqueous condition, spherical granules of enzyme made better recovery of enzme activity than tablet ones by 10 times. Combined processing of both mixer granulation and enteric granule film coating provided the noble enteric coated granules, in the sense of disintegration and stabilities, was obtained from using 0.125% fatty alcohol in coating solution.

• 한국축산식품학회지
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• 제38권3호
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• pp.636-652
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• 2018

The study aims to determine the optimum sterilization rate and water activity of Chinese traditional smoke-cured bacon product (Larou) in the preservation with natural coating solution. With the response surface methodology (RSM), we analyzed 3 factors of processing conditions (the concentration of lysozyme, concentration of sodium alginate, and concentration of chitosan) and 2 response factors (sterilization rate and water activity). Sterilization rate and water activity of Larou were largely affected by the concentration of lysozyme, concentration of sodium alginate, and concentration of chitosan. The final optimum concentrations of lysozyme, sodium alginate, and chitosan were 0.09, 1.40, and 1.60% and realized the high sterilization rate. Water activity of sliced Larou was significantly correlated with the sterilization rate. Low-field nuclear magnetic resonance analysis verified the optimum processing conditions. The coating resulted in 99.69% rate of reducing bacteria after 30-day storage. The data of the total number of colony, peroxidation value, moisture content, pH, and sensory evaluation provided the theoretical basis for extending the shelf life of Chinese traditional smoke-cured bacon product (Larou) with natural coating solution.

• Composites Research
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• 제33권4호
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• pp.185-190
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• 2020

티타늄은 우수한 생체 적합성으로 임플란트 재료로 많이 사용되고 있지만 높은 비용과 뼈 대비 높은 영률로 인한 문제점이 있다. 이를 대체할 재료로 마그네슘합금이 주목받고 있다. 마그네슘합금은 티타늄과 마찬가지로 생체 적합성이 우수하고 뼈와 비슷한 영률을 가지고 있다. 하지만 부식으로 인한 내식성 문제가 있어 이를 해결하기 위해 다양한 표면 처리법이 연구되고 있다. 본 연구는 EDTA를 포함한 전해 용액에서 AZ31 마그네슘 합금 표면에 전해플라즈마공정으로 세라믹 코팅 층을 성장시키고 형성된 코팅의 특성은 SEM, XRD를 통해 미세구조 및 형상을 분석하였고 코팅 층의 미세 경도 측정을 하였으며, 사람의 혈장과 비슷한 성분인 SBF용액 내에서 부식테스트를 통해 생체내에서의 부식 특성을 평가하였다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.265-266
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• 2006

The chemical conversion coating formed on magnesium alloy investigated for low cost and harmless in environment by using the colloidal silica as the main component. The film formed in 298 K is thick, the film, which was thought combination of Si-O, was formed. The film formed in 313 K is thinner than that in 298 K. The quantity of film formed at high temperature such as 333 K and 353 K is smaller than dissolved quantity. At the anodic polarization experiment, corrosion resistance in sealing by hot water after chemical conversion treatment in basic solution condition get worse than that in comparison with basic solution condition. In salt spray test, the ratio of black rust on specimen that did not conducted chemical conversion treatment was five times or more compared with those of chemical conversion treated specimen. The film thickness of chemical conversion coating produced by alkali treatment process is thinner than in comparison with that of specimen produced in basic chemical conversion treatment solution condition. It is thought, however, that it showed good corrosion resistance during salt spray test because the area of microcracks is small.

• 한국표면공학회지
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• 제40권3호
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• pp.138-143
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• 2007

The effects of texturing and anti-reflection coating on the reflection properties of multi-crystalline silicon solar cell have been investigated. The chemical solutions of alkaline and acidic etching solutions were used for texturing at the surface of multi-crystalline Si wafer. Experiments were performed with various temperature and time conditions in order to determine the optimized etching condition. Alkaline etching solution was found inadequate to the texturing of multi-crystalline Si due to its high reflectance of about 25%. The reflectance of Si wafer texturing with acidic etching solution showed a very low reflectance about 10%, which was attributed to the formation of homogeneous. Also, deposition of ITO anti-reflection coating reduced the reflectance of multi-crystalline si etched with acidic solution($HF+HNO_3$) to 2.6%.

• 한국표면공학회지
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• 제54권6호
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• pp.315-323
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• 2021

In general, surface treatments of electroless Ni-P coating are extensively applied in the industry due to their excellent properties for considerable wear resistance, hardness, corrosion resistance. This study aims to determine the effect of ultrasonic conditions on the morphology, alumina content, roughness, hardness, and corrosion resistance of electroless Ni-P-Al₂O₃ composite coatings. The characteristics were analyzed by Energy-dispersive X-ray spectroscopy (EDX), x-ray diffractions (XRD), and atomic force microscopy (AFM), etc. In this study, the effect of ultrasonic condition uniformly distributed alumina within Ni-P solution resulting in a smoother surface, lower surface roughness. Furthermore, the corrosion resistance behavior of the coating was analyzed using tafel polarization curves in a 3.5 wt.% NaCl solution at 25 ℃. Under ultrasonic, Al₂O₃ content in Ni-P composite solution increased from 0.5 to 5.0 g/L, Al₂O₃ content at 3.0 g/L was showed a significantly enhanced corrosion resistance. These results suggested that ultrasonic condition was an effective method to improve the properties of the composite coating.

• 한국세라믹학회지
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• 제47권5호
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• pp.381-386
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• 2010

Some basic properties of inorganic coatings hardened by the room temperature reaction with alkalies were examined. The coating paste was prepared from the powders in the system $Al_2O_3-SiO_2$-CaO using blast furnace slag, fly ash and amorphous ceramic fiber after mixing with a solution of sodium hydroxide and water glass. The mineralogical and morphological examinations were performed for the coatings prepared at room temperature and after heating to $1200^{\circ}C$ respectively. The binding force of the coating hardened at room temperature was caused by the formation of fairly dense matrix mainly composed of oyelite-containing amorphous phase formed by the reaction between blast furnace slag and alkali solution. At the temperature, fly ash and ceramic fiber was not reacted but imbedded in the binding phase, giving the fluidity to the paste and reinforcing the coating respectively. During heating up to $1200^{\circ}C$, instead of a break in the coating, anorthite and gehlenite was crystallized out by the reaction among the binding phase and unreacted components in ternary system. The crystallization of these minerals revealed to be a reason that the coating maintains dense morphology after heating. The maintenance of binding force after heat treatment is seemed to be also caused by the formation of welldispersed fiber-like mineral phase which is originated from the shape of the amorphous ceramic fiber used as a raw materials.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 추계총회 및 학술대회 논문집
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• pp.134-134
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• 2012

• Advances in materials Research
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• 제1권3호
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• pp.233-243
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• 2012

Thermal reactive diffusion coating of vanadium carbide on DIN 2714 steel substrate was performed in a molten borax bath at $950-1050^{\circ}C$. The coating formed on the surface of the substrate had uniform thickness ($1-12{\mu}m$) all over the surface and the coating layer was hard (2430-2700 HV), dense, smooth and compact. The influence of the kinetics parameters, temperature and time, has been investigated. Vanadium carbide coating was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and X-ray diffraction analysis (XRD). The corrosion resistance of the coating was evaluated by potentiodynamic polarization in 3.5% NaCl solution. The results obtained showed that decrease of coating microhardness following increasing time and temperature is owing to the coarsening of carbides and coating grain size.

• 공업화학
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• 제8권5호
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• pp.709-714
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• 1997

암모니아수를 이용한 가수분해법에 의해 운모의 이산화티타늄 피복을 시행하여 합성조건의 영향을 조사했다. 운모표면에 균일한 $TiO_2$ 피막을 얻기 위해서는 운모의 입자경이 작고 비표면적이 넓은 쪽이 유리하다. 또한 반응용액상에서 생선된 입자는 운모표면에 유리상태로 부착하여 피막을 불균일화시키므로, 용액상에서의 수화 $TiO_2$ 콜로이드 입자 생성속도를 느리게 제어할 필요가 있다. 본 실험에서 운모의 크기는 $14.7{\mu}m$, 운모 슬러리 용액의 pH는 2.5, $TiOSO_4$ 용액의 F.A.는 291, 반응온도는 $80{\sim}100^{\circ}C$ 정도가 적당하였다. 이상의 결과로부터 균일한 피복을 실현하기 위해서는, 반응온도를 변화시켜 입자의 석출율을 제어하는 일이 필요하다. 이 경우 석출율이 큰 쪽이 균일하고 치밀한 피막을 얻을 수 있었다. 이렇게 하여 얻어진 $TiO_2$ 피복 운모는 $900^{\circ}C$의 소성전후에서 형태에 큰 변화는 없었다.