• 한국세라믹학회지
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• 제27권1호
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• pp.109-117
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• 1990

Magnetite for Water-based ferrofluid was synthesized by air oxidation of aqueous suspension in the pH range 7-12 at $65^{\circ}C$. The optimum condition of magneite formation was delineated by examining various physicochemcial properties such as Fe2+ content, phase characteristics, MHC and $\sigma$max. The point of zero charge of iron oxide powders obtained at various pH conditions were correlated with the oxidation state of Fe in the iron oxide. The magnetite powder prepared at pH 9 ws dispersed using sodium oleate and sodium dodecylbenzenesulfonate (SDBS) as dispersants, and the dispersion characteristics of the magnetite ferrofluid were examined by means of the fraction of solid dispersed, zeta potential data and FT-IR spectrum. A simple calculation on the potential energy of two interacting magnetite particles showed that the dispersion stability was directly correlated with height of the potential energy barrier or the shape of zeta potential.

• 대한의용생체공학회:의공학회지
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• 제33권2호
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• pp.89-97
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• 2012

The purpose of this study is to develop the guideline of the physicochemical and mechanical properties evaluation for silicone gel filled breast implants. First of all, the use and development status for silicone gel filled breast implants were investigated, and then, standard and criteria about performance evaluation established by the international organizations such as ASTM, FDA guidance and ISO were examined. To evaluate the mechanical properties, data research and testing for breaking strength, elongation, tensile set, joint intensity, silicone gel cohesion, weight loss from heating, static rupture resistance, impact resistance test, fatigue test, and gel bleed were performed. On the other hand, to evaluate the physicochemical properties, volatile matter, extent of cross linking, heavy metals, and extractable were analyzed. In this study, results for general function, mechanical properties and physicochemical properties were examined and reviewed for the accordance with international standard, and objective and standardized guideline was provided.

• 한국식품위생안전성학회지
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• 제1권1호
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• pp.39-46
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• 1986

Comparison of ethylene oxide(E.O) fumigation and gamma irradiation on the sterilization, microbiological, physicochemcial and sensory quality of dried fishery products (shucked shellfish and mussel powder) were investigated. The viable cell count of mesophilic total bacterial was reduced by over 2 to 3 log cycles with irradiation of 3 to 5 kGy, and those samples were completely sterilized by irradiation dose of 7 to 10 kGy. In view of reduction of microorganisms, D10 value of each samples were ranged from 1. 36-1. 46 kGy. fungi, mesophilic spores, acid tolerant bacteria and coliforms were sterilized at 5 to 7 kGy irradiation but E.O. fumigation proved insulfficient to eliminate the mesophilic total bacteria and fungi. In the physicochemical and sensory quality of samples, such as the amino acid, TBA value, TMA-N, color difference and overall acceptability irradiated sample with optimum dose was similar to those of the nonirradiated sample, while E.O. fumigated sample was remarkably deteriorated in the physicochemical and sensory quality of samples.

• 한국환경농학회지
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• 제36권3호
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• pp.175-183
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• 2017

1. 본 연구의 향미의 품종별, 이앙시기별 이화학적 특성 평가한 결과 품종간의 차이는 나타나지 않았으며 단백질 함량은 5.8~7.3%로 나타났고 5월 22일 조기이앙시 평균 6.4%로 가장 낮았으며 지방 함량은 조기이앙시 평균 $2.6{\pm}0.1%$, 보통기이앙시 평균 $2.5{\pm}0.1%$, 만기이앙시 평균 $2.2{\pm}0.1%$를 나타내어 이앙시기가 빠를수록 높은 경향을 나타내었다. 2. 향미 품종 중 Hyangmibyeo 2 ho가 강하점도의 값이 152.3RVU로 가장 높아 전분의 구조가 호화되기 쉬운 구조적 특성을 가지고 다른 품종에 비해 밥맛이 우수 할 것으로 판단되며 이앙시기는 조기나 보통기 이앙이 좋을 것으로 판단된다. 3. 향미 품종, 이앙시기별 향기성분 정량 분석 비교에서는 향기성분 등 중 대표적으로 2-acetyl-1-pyrroline (2AP)를 지표성분으로 정하여 정량분석 한 결과 품종 중에는 Aromi가 $41.7{\sim}66.7{\mu}g/100g$으로 가장 높은 2AP의 함량을 나타내었고 이앙시기의 영향은 모든 품종에서 각각 보통기이앙시 평균 $37.4{\mu}g/100g$, 만기이앙시 $31.5{\mu}g/100g$ 조기이앙 시 평균 $37.4{\mu}g/100g$ 순으로 나타났다. 최적 이앙시기는 생산력 검정 등의 다양한 요소를 고려해 볼 때 6월 5~20일 사이에 이앙하는 것이 최적으로 판단된다.