• 한국식품조리과학회지
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• 제14권3호
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• pp.213-218
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• 1998

The changes in gelatinization patterns of potato were investigated while steeping in water for 7 days at 30${\pm}$1$^{\circ}C$. The transmittance of 0.1% starch suspension was increased rapidly from 60$^{\circ}C$ in raw starch and the starch steeped for 2 days, and increased rapidly from 65$^{\circ}C$ in the starch steeped for 4 and 6 days. As the steeping period increased, the transmittance was decreased at above condition. The gelatinization temperature of the starch measured by differential scanning calorimetry was increased from 62.79$^{\circ}C$ to 63.72$^{\circ}C$ as the steeping period increased. The gelatinization enthalpy reached the maximum in the starch steeped for 4 days. By amylograph, the initial gelatinization temperature was increased from 66$^{\circ}C$ to 84$^{\circ}C$ as the steeping period increased. Peak viscosity was decreased during steeping and the starch steeped for 5 days had no peak viscosity. Peak height after cooling to 50$^{\circ}C$ was increased up to the 4th day and began to decrease. As the steeping period increased, there was much loss of birefringence at higher temperature. The crystallinity by X-ray diffraction disappeared from 65$^{\circ}C$.

• 대한가정학회지
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• 제38권3호
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• pp.121-130
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• 2000

This study attempted to determine the effects of sucrose, NaCl and acetic acid on the quality characteristics of cooked rice stored at 20$\^{C}$ for 72 hours. It conducted a moisture content, color value, texture and RVA(Rapid Visco Analyser) viscosity on stored cooked rice. Moisture contents of all groups ecreased during storage and that of cooked rice with NaCl were significantly lower than that of other groups. In color, lightness(L) of cooked rice with various additives seemed higher than that of control group and reduced b value of cooked rice with acetic acid showed that the color became less yellow. In texture, the hardness of cooked rice with NaCl and sucrose was higher than that of control group, whereas that of cooked rice with acetic acid was similar to that of control group. Adhesiveness of cooked rice with acetic acid was higher than that of other groups and it was shown that texture could be improved by the addition of acetic acid. The initial viscosity of cooked rice with acetic acid was markedly higher than that of other groups and finial viscosity was lower than that of other groups. It seemed that addition of acetic acid could retard the retrogradation of stored cooked rice.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2001년도 춘계 학술발표회 논문집
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• pp.11-14
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• 2001

Our study have aimed to identify the deformation and breakup mechanism of minor phase in polymer blends under uniaxial enlongational flow. Experimentally, we measured the transient elongational viscosity of PS/HDPE blends using the uniaxial elongational rheometer at two temperatures. And we observed the evolution of blend morphology with elongation time. Morphological change was observed by quenching the specimen after deformation. If the viscosity variation of PS was compared with that of HDPE at each temperature, PS showed larger temperature dependence than HDPE. At 155$^{\circ}C$, the dispersed phase of larger size were easily affected by affine deformation. The initial spherical shape changed to flat ellipsoid at first, then flat ellipsoid to bulbous shape, and bulbous to thin thread and its satellites. But dispersed phase of smaller size showed the change from sphere to ellipsoid. At 175$^{\circ}C$, the dispersed phase were mostly deformed from spherical shape to ellipsoid. As a result, the morphological change of dispersed phase in elongational deformation is affected by chain flexibility and viscosity ratio. We need to further study to make sure the mechanism of elongation of viscoelastic polymer blends.

• 한국식생활문화학회지
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• 제29권4호
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• pp.348-354
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• 2014

The purpose of this study was to investigate the effects of Curcuma aromatica powder on the functional and sensory characteristics of Mandupi. Various Mandupi samples were prepared with wheat flour along with addition of various amounts of Curcuma aromatica powder, after which instrumental characteristics and sensory evaluations were investigated. According to the amylograph data, the composite Curcuma aromatica powder-wheat flour samples showed increased gelatinization temperatures with increasing Curcuma aromatica powder content, whereas initial viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity were reduced. In terms of Hunter's color values, L value decreased while a and b values increased with increasing Curcuma aromatica powder content. Besides cooked weight, cooked volume and turbidity of Mandupi increased as the addition level of Curcuma aromatica powder increased. In terms of textural characteristics, addition of Curcuma aromatica powder increased springiness, chewiness, and brittleness, whereas springiness and adhesiveness decreased. Based on sensory evaluations, the overall preference of Mandupi with 3% added Curcuma aromatica powder was higher than that of control.

• 한국추진공학회지
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• 제23권5호
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• pp.60-66
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• 2019

본 논문은 알루미늄 함량 변화에 따른 로켓보조추진탄(RAP) 용 추진제의 공정특성(점도), 기계적 물성, 연소특성, 지상 및 비행시험 결과에 관하여 기술하였다. 알루미늄 함량이 증가되면 초기점도는 감소하고 점도 build-up은 빨라지며 연소속도 및 압력지수가 감소하는 것을 확인하였다. 지상연소시험에서는 알루미늄이 10 wt% 함유된 RAP이 알루미늄이 2 wt%, 18 wt% 함유된 RAP에 비해 총역적이 약 5% 높았으며, 이론성능 대비 모터 효율은 알루미늄이 18 wt% 함유된 조성이 85.6%로 가장 낮았다.

• 한국식생활문화학회지
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• 제24권2호
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• pp.206-211
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• 2009

The purpose of this study was to investigate the effect of shrimp flour on quality characteristics of dumpling shell. Dumpling shell samples were prepared with wheat flour along with the addition of different amount of shrimp flour, followed by functional measurements and sensory evaluations. According to amylograph data, the composite shrimp flour/wheat flour samples had increased gelatinization temperature with increasing shrimp flour content, while initial viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity were reduced. In terms of color values, L value decreased, but a and b values increased with increasing shrimp flour content. Furthermore, the addition of shrimp flour increased hardness and decreased chewiness in all samples. Overall, sensory evaluations proved that dumpling shell with 10% added shrimp flour was preferred over the other samples.

• 한국식생활문화학회지
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• 제23권2호
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• pp.252-257
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• 2008

The purpose of this study was to investigate the effects of skate (Raja kenojei) flour on the functional and sensory characteristics of Mandupi. Mandupi samples were prepared with wheat flour along with the addition of different amounts of skate flour, followed by functional measurements and sensory evaluations. According to the amylograph data, the composite skate flour-wheat flour samples had increased gelatinization temperatures with increasing skate flour content; whereas initial viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity were reduced. In terms of color values, L and b values decreased, but the a-value increased with increasing skate flour content. Furthermore, the addition of skate flour increased hardness, springiness, chewiness, and adhesiveness in the samples. Overall, based on sensory evaluations, the Mandupi containing 5% skate flour was preferred over the other samples.

• 한국조리학회지
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• 제2권
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• pp.183-207
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• 1996

This study is to investigate the effect on the quality and properties of bread affected by licorice extract addition. The measurements of the farinograph, extensograph and amylograph on dough are carried out. And the evaluations of volumetric changes during fermentation, shape of bread crumb, sensory test, firmness are obtained. The obtained results are as follows. 1. Proximate compositions of licorice extract are as follows: moisture 73.7%, crude protein 4.1%, crude lipid 2.8%, crude ash 1.4%. 2. Water absoorption, arrival time dough development time mechanical tolerence index and valorimeter value are increased but stability is decreased with the addition of licorice extract. 3. The resistance to extension is increased but extensibility is decreased with the addition of licorice extract. 4. The initial pasting and highest viscosity temperatures are not affected but the highest viscosity is steepy decreased over 1.0% addition of licorice extract. 5. The volume of dough during fermentation and specific volume of bread is decreased with the addition of licorice extract. 6. The grain of bread is to be rough and irregular and the firmness is increased with the addition of licorice extract. 7. The records of sensory test are decreased with the addition of licorice extract.

• 소성∙가공
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• 제8권2호
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• pp.188-199
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• 1999

Semi-Solid Forming Process(Thixoforming, Rheocasting) is a novel forming process which has some advantages compared with conventional die casting, squeeze casting and hot/cold forging. In this study. Thixoforming process was selected as analysis processing in terms of billet handling and easiness of automation process. The Thixoforming process consists of reheating process of billet, billet handling, filling inot the die cavity and solidification of SSM part. In filling process, two rheology models which were Newtonian and Non-Nettonian model (Ostwald-deWaele)were verified with experimental results. The Ostwald-deWaele model shows the good agreement to the real flow and filling phenomena in die cavity. To give a boost the economical efficiency of Thixoforming process and to ensure the good forming result, reheating device coupled die set was proposed and the initial billet temperature for system that was found from experimental resluts. This study presents an overview of application of numerical analysis for simulation of semi-solid metal forming process to reduce the lead time for development of manufacturing part in industrial field.

• 한국분무공학회지
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• 제25권1호
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• pp.15-20
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• 2020

This study aims to investigate injection rate and microscopic spray characteristics of diesel fuel containing fine air bubble (FBD). fine bubble was generated by cavitation theory using bubble generator. Fuel spray was injected into constant volume chamber and visualized by high speed camera. The injection rate data was acquired with bosch tube method. Injection rate of finebubble diesel was very similar with that of diesel. It showed slightly faster injection start by 5 ㎲ attributed to the low viscosity characteristics. In microscopic spray visualization, fine bubble diesel spray showed unsymmetric spray shape compared with diesel spray. It also showed very vigorous spray atomization performance during initial spray development. Improved atomization was also attributed to the low viscosity and surface tension of finebubble diesel fuel.