• Journal of Dairy Science and Biotechnology
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• 제26권2호
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• pp.51-56
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• 2008

Using central composite design, we have designed optimization of the manufacturing of processed butter. And response surface analysis by least-square regression was used Statistical Analysis System(SAS). Central composite design can be achieved by response surface techniques that allow flexibility in modeling and analysis. Response surface methodology(RSM) was used to optimize hardness(%) using as independent variables; the content of butter($X_1$), ranging from 50 to 90(%), the content of soybean oil($X_2$), from 0 to 20(%), and the hydrogenated soybean oil($X_3$) from 0 to 4(%). The results on the regression coefficients calculated for overrun by response surface by least-square regression(RSREG) were followed. It was considered that the linear regression was significant(p<0.01). As for the processed butter, the regression model equation for the hardness(Y, %) to the change of an independent variable could be predicted as follow: $Y=60.88-8.92X_2-{29.3X_2}^2$. The optimal for the manufacturing of processed butter were determined at the content of butter of 88.22%, soybean oil of 6.71% and hydrogenated soybean oil of 2.36%, respectively. Optimum compositions were resulted in hardness of 65.78 N. Finally the reference sample(Butter in the morning, Seoul Dairy Co-op.) and processed butter manufacturing under the optimal conditions were compared with spreadability test. The spreadability scores result from reference sample and butter under optimal conditions was not found a significant difference.

• 한국식품영양과학회지
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• 제33권7호
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• pp.1230-1236
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• 2004

능이버섯의 건조과정에 따른 물성 변화를 조사하기 위하여 수분함량 86.68%인 능이버섯을 5$0^{\circ}C$, 1.5 m/s, 상대습도 15%의 조건에서 건조하면서 Rheometer로 물성을 측정하였다. 능이버섯은 건조가 진행됨에 따라 압축거리는 약 60%가 감소하였다. 능이버섯을 파괴시키는데 필요한 힘은 감소하였으며, 부드러운 정도를 나타내는 수치 또한 감소하였으나 경도는 증가하였다. 이는 건조가 진행되면서 조직이 단단해지고 수축되면서 나타나는 현상이라고 사료된다. 능이버섯의 색도는 건조과정 중L값, a값, b값이 감소하여 대체로 검게 변하였으며, 구조는 두께의 수축율이 72.8%인데 반해 면의 수축율은 38.05%로 두께의 수축이 면의 수축보다 2배정도 큰 것을 보였다. 즉, 건조 중 능이버섯은 갓의 크기가 작아지면서 두께가 상당히 얇아지는 것으로 나타났다 능이버섯을 건조한 후 재수화시 재수화율은 약 30%정도로 나타났고, 응력이 최고로 도달하는데 걸리는 시간 또한 6.41초로 44.2%정도 회복되었다.

• 한국분말재료학회지
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• 제29권2호
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• pp.99-109
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• 2022

Powder flowability is critical in additive manufacturing processes, especially for laser powder bed fusion. Many powder features, such as powder size distribution, particle shape, surface roughness, and chemical composition, simultaneously affect the flow properties of a powder; however, the individual effect of each factor on powder flowability has not been comprehensively evaluated. In this study, the impact of particle shape (sphericity) on the rheological properties of Ti-6Al-4V powder is quantified using an FT4 powder rheometer. Dynamic image analysis is conducted on plasma-atomized (PA) and gas-atomized (GA) powders to evaluate their particle sphericity. PA and GA powders exhibit negligible differences in compressibility and permeability tests, but GA powder shows more cohesive behavior, especially in a dynamic state, because lower particle sphericity facilitates interaction between particles during the powder flow. These results provide guidelines for the manufacturing of advanced metal powders with excellent powder flowability for laser powder bed fusion.

• Journal of Dairy Science and Biotechnology
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• 제33권4호
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• pp.247-252
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• 2015

본 연구는 원유로부터 면역효능이 우수한 젖산균 Streptococcus macedonicus LC743을 분리하였고, 이 균으로 제조한 모짜렐라 치즈와 상업균주로 제조한 모짜렐라 치즈에 대해 물성학적 특성을 비교시험 하였다. S. macedonicus LC743을 이용한 절단 전 커드의 조직특성은 상업균주로 제조된 절단 전 커드보다 조직이 약한 반면, 상업균주와 S. macedonicus LC743 균주로 제조된 절단 전 커드보다 강하거나 비슷한 수준을 보였다. 치즈의 경우는 S. macedonicus LC743으로 제조된 치즈가 Hardness, Sprininess, Cohesiveniss, Gumminess, Chewiness에서, Fracturability는상업균주로제조한치즈에서, Adhesiveness는 상업균주와 S. macedonicus LC743으로 제조된 치즈에서 각각 높은 값을 나타내었다. 전자현미경 관찰에서 상업균주로 제조된 치즈는 표면이 거친 모습을 보인 반면, S. macedonicus LC743로 제조된 치즈는 케이신 마이셀이 작은 덩어리가 뭉쳐져 있어 작은 계곡을 형성하는 것을 볼 수 있었다.

• 한국인쇄학회지
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• 제12권1호
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• pp.145-157
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• 1994

Litho printing ink vehicles based on rosin modified phenolic are faster drying, have better durability, are harder and glosser and have greater resistance to water than ones based on ester gums. Ink-Water balance and rheological properties are important in litho printing process. These physical properties is concerned with molecular weight of Resin to use vehicle. So this paper was studied about the effects of changing molecular weight of Rosin modified phenolic on surface tension, viscosity, pseudoplasticity and printability of Litho Inks. The results were as follows. 1) The surface tension of model inks depended on the molecular \veight of the resin : Dispersion componnent of ink increase but non dispersion component decrease as molecular weight of Resin increase. 2) Water pick-up of litho ink is more fast balance, using low molecular weight of Resin. 3) Viscosity, Yield value and Newtonian value of model inks increase as molecular weight of Resin increase. 4) The litho ink prepared with the modified phenolic of which molecular weight is about 20000 showed the highest printing density and gloss.

• 한국식품영양과학회지
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• 제31권3호
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• pp.417-422
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• 2002

절임은 배추의 맛을 결정하는 중요한 공정이므로 배추의 소금 절임시 가장 중요한 영향인자인 소금농도, 절임시간 및 절임온도에 따른 관능적 특성 및 물리적 특성 에 대하여 반응표면분석을 실시하였다. 절임배추의 외관에 대한 관능평점은 소금농도 11.28%, 절임시간 9.75 hr 및 절임온도 12.81$^{\circ}C$에서 가장 높았으며, 맛에 대한 관능평점은 소금농도 11.19%, 절임 시간 11.38 hr 및 절임온도 13.58$^{\circ}C$에서 가장 높게 나타났다. 조직감에 대한 관능평점은 소금농도 11.24%, 절임시간 11.71 hr, 절임온도 13.57$^{\circ}C$에서 가장 높게 나타났으며, 전반적인 기호도에서는 소금농도 11.52%, 절임시간 12.86 hr, 절임온도 13.07$^{\circ}C$에서 가장 높은 관능평점을 나타내었다. 물리적 특성으로 견고성과 씹힘성은 소금의 농도가 증가할수록 값이 낮아지는 경향을 보였으며 소금의 농도에 가장 영향을 많이 받고 절임시간, 절임온도의 순으로 영향을 받는 것으로 나타났다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.198-201
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• 1997

The new system for identification of organic vapours and analysis method of mechanism between organic vapours and sensitive materials were attempted using the resonant resistance and resonant frequency of Quartz Crystal Analyzer (Q. C. A.). The resonant resistance shift means rheological changes in sensitive LB films occurred by the adsorption of organic vapours, while the resonant frequency shift represent the mass of organic vapour loaded in or on the sensitive LB films. It is thought that we can obtain more accurate response mechanism of organic vapour using the resonant frequency and resonant resistance diagram. The polymeric sensitive material were quantitively depositied using the LB method. In the experimental results, the adsorption behavior of organic vapour response can be decided by two type ; surface adsorption and penetration into sensitive material. Organic vapours had different positions in the Frequency-Resistance (F-R) diagram as to the kinds and concentrations of organic vapours. Thus F-R diagram can be applied to the development of one channel gas sensing system using the Quartz Crystal Analyzer.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.5-6
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• 2006

Molecular motion at the surface of monodisperse polystyrene (PS) films with various chain end groups was studied by scanning probe microscopy. Surface glass transition temperature ($T_{g^s}$) of the PS films was much lower than the corresponding bulk value. And, the magnitude of $T_{g^s}$ was strongly dependent on chain end chemistry. This result can be explained in terms of the chain end concentration at the surface. Time-temperature superposition principle was applied to rheological analysis at the surface. The apparent activation energy of the surface ${\alpha}_{a}$-relaxation process was approximately a half of that for the bulk sample. This result clearly indicates that the cooperativity for the surface segmental motion was reduced in comparison with that in the bulk region.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2002년도 춘계 학술발표회 논문집
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• pp.25-27
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• 2002

In this study we investigated the reaction kinetics by a convenient but useful method-rheology to characterize the interface between two immiscible blends with a Reactive compatibilizer. Also, we made an attempt to correlate changes of interface roughness with rheological properties. The blend systems employed in this study was mono-carboxylated polystyrene (PS-mCOOH) and an poly(methyl methacrylate-ran-glycidylmethacrylate) (PMMA-GMA). PS-mCOOH was synthesized by an anionic polymerization and PMMA-GMA by a free radical polymerization. We prepared two plates of each polymer using compression molding with a smooth surface molder, then put one upon another. As soon as these two plates welds together inside a rheometer under nitrogen environment, the torque and moduli were obtained with reaction time at different temperatures. Through the analysis of this modulus change with reaction time, we estimated interfacial reaction and roughening. The increment of modulus in initial state can be correlated to the extent of reaction. We obtained the reaction kinetic constant by fitting appropriate kinetic equation into experimental data. We also showed that increment of modulus in later state was due to by roughened interface.

• 동아시아식생활학회지
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• 제18권1호
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• pp.1-8
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• 2008

In this study the rheological properties of Jeung-pyun prepared with soybean protein isolate (SPI) were investigated. SPI Jeung-pyun samples were manufactured with 3% whole protein, 7S protein, or 11S protein (w/w). In terms of moisture content the Jeung-pyun samples prepared with soybean flour had greater moisture contents than the control group. With the addition of SPI water binding capacity solubility and swelling power increased. Dough pH decreased during the fermentation, but increased after steaming and the SPI Jeung-pyun samples presented higher pH levels han the control group. Foaming ability was significantly strong in the 7S, 11S and whole protein groups. The surface structures of the 7S, 11S and whole protein Jeung-pyun samples displayed small uniform pores when examined by SEM. Overall, the results suggest that SPI can contribute to quality improvements in Jeung-pyun through effects on dough fermentation.