• Title/Summary/Keyword: 점착성

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FRACTAL DIMENSION OF SIMULATED SEDIMENTS (모의류사의 쪽거리 차원)

  • 김형수;윤용남
    • Water for future
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    • v.27 no.3
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    • pp.115-121
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    • 1994
  • Cohesie sediment movement in estuarine systems is strongly affected by the phenomena of aggregation and flocculation. Aggregation is the process where primary particles are clustered together in tightly-packed formations; flocculation is the process where aggregates and single particles are bonded together to form large particle groups of very low specific density. The size, shape and strength of the flocculants control the rate of deposition and the processes of pollutant exchange between suspended sediments and ambient water. In estuarine waters, suspended sediments above the lutocline form the mobile suspension zone while below the lutocline they form the stationary suspension zone. Suspended particles in the mobile zone are generally in a dispersed state and the controlling forces are the Brownian motion and the turbulent flow fluctuations. In the stationary suspension zone, the driving force is the gravity. This paper discusses the settling and particle flocculation characteristics under quiescient flow conditions. Particles are entering the study domain randomly. Particles in the mobile suspension zone are simulated by using the Smoluchowski's model. Flocs created in the mobil suspension zone are moving into the stationary suspension zone where viscosity and drag effects are important. Utilizing the concepts of the maximum Feret's diameter and the Minkowski's sausage logic, the fractal dimension of the flocs within the stationary suspension is estimated and then compared with results obtained by other studies.

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Characteristics of white pan bread with roasted rice bran (볶은 미강을 첨가한 식빵의 품질 특성)

  • Shin, Hyun-Kwang;Lee, Jeong-Hoon;Lee, Si-Kyung
    • Korean Journal of Food Science and Technology
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    • v.49 no.4
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    • pp.401-407
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    • 2017
  • This study investigated the effect of roasted rice bran (RRB) on bread quality. Bread containing RRB showed small and specific loaf volumes. Baking and cooling loss rates of bread with RRB were lower than bread without RRB. The pH of bread decreased and total titratable acidity increased with increase in the amount of RRB. Water activity (Aw) and moisture contents of bread increased with RRB levels in bread. Bread containing RRB presented lower L value and higher redness (a) and yellowness (b) values. Crumb hardness, springiness, and gumminess increased, whereas cohesiveness decreased upon addition of RRB. Addition of 5% RRB resulted in higher scores in sensory evaluation than the control, however, bread with 15% RRB had the lowest score. Therefore, 5% RRB can be used in bread production.

Characteristics of Yellow Layer Cake Made with Mandarin Powder (밀감 분말을 첨가한 옐로우 레이어 케이크의 품질특성)

  • Park, Yeong-Sun;Shin, Sol;Shin, Gil-Man
    • Food Science and Preservation
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    • v.15 no.5
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    • pp.656-661
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    • 2008
  • basic formulation. Moisture content of 13.72%, crude protein 5.22%, crude lipid 1.31%, crud ash 1.94%, respectively. The pH of yellow layer cake decreased with increasing mandarin powder concentrations. In color values, with increase of mandarin powder concentration. The volume decreased with increasing mandarin powder concentration. The weights of yellow layer cake increased with increasing mandarin powder concentration. L value and a value decreased with increasing mandarin powder concentration in the crumb. b value increased with increasing mandarin powder concentration. The baking loss rate decreased with increasing mandarin powder. In the texture hardness, gumminess, chewiness and adhesiveness of yellow layer cakes significantly increased with increasing mandarin powder concentration. springiness and cohesiveness of yellow layer cakes significantly decreased. In the results of sensory evaluation, when compared to the control, the bread added to 9% of mandarin powder was superior to in color and flavor, while was similar to texture and taste.

Quality Characteristics of Korean Pan-fried Food (Jeon) Added with Lactic-fermented Rice Flour (유산발효 쌀가루의 혼합비율에 따른 전(煎)의 품질특성)

  • Chang, Young-Eun;Kim, Jin-Sook;Lee, Ji-Hyun;Kim, Kyung-Mi;Kim, Gi-Chang
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.6
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    • pp.868-876
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    • 2014
  • This study was performed to investigate the effects of lactic-fermented rice flour on the quality characteristics of pan-fried food (Jeon). Pan-frying flour containing 5~20% lactic fermentation rice flour mixture was prepared. In rapid visco analyzer examination, peak viscosity, trough, final viscosity, breakdown, and setback of the lactic-fermented rice flour mixture were lower than those of rice flour or wheat flour. The L-value (lightness) of Jeon decreased with increasing the ratio of lactic-fermented rice flour. On the other hand, a-value (redness) and b-value (yellowness) increased with increasing ratio of lactic-fermented rice flour. Texture profiles showed that Jeon prepared with lactic-fermented rice flour mixture had higher springiness and gumminess than 100% rice flour. The oil absorptions of Jeon prepared with 100% rice flour and 20% lactic-fermented rice flour were 7.5% and 6.33%, respectively. For digestive properties, Jeon prepared with lactic-fermented rice mixture showed a greater amount of rapidly digestible starch and lower amount of slowly digestible starch. In the sensory evaluation, Jeon prepared with lactic-fermented rice mixture showed higher scores for appearance, flavor, and taste than others (rice flour and wheat flour). Especially, Jeon prepared with 10% lactic-fermented rice mixture showed the highest overall preference. In conclusion, the results demonstrate that lactic-fermented rice flour may prove quite useful as a pan-frying flour with desirable qualities properties.

Structure and Cell Adhesion Behavior of Silk Fibroin Nanofiber, Microfiber and Film (실크 피브로인 나노섬유, 마이크로섬유, 필름의 구조 및 세포점착 특성비교)

  • 김소현;남영식;박원호;민병무
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.04a
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    • pp.293-294
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    • 2003
  • 견 피브로인은 대표적인 섬유상 단백질의 하나로 생체적합성, 생분해성, 저독성 등의 유용한 특성을 가지므로 생체재료로 상당한 관심과 연구의 대상이 되어왔다. 우리는 최근의 연구에서 견 피브로인을 생사로부터 추출한 다음, 포름산을 용제로 하여 전기방사함으로써 나노섬유를 제조하고 이들의 각화세포에 대한 친화력을 확인한 바 있다. 본 연구에서는 견 피브로인의 구조체를 나노섬유 부직포, 필름, 마이크로 섬유로 구성된 직물 둥의 형태로 하여 그들의 2차 구조를 비교함과 동시에 구조적 특성이 각화세포와의 친화력에 어떠한 영향을 미치는 가를 비교ㆍ검토 하고자 하였다. (중략)

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A Study of Garlic-Yackwa Development 1. Quality Characteristics of Garlic-Yackwa Substituted with Different Amounts of Garlic Juice (마늘약과의 개발에 관한 연구 1. 마늘즙 대체량을 달리한 마늘약과의 품질특성)

  • 문숙임
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.8
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    • pp.1285-1291
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    • 2003
  • This study was carried out to find optimum substitution amounts of garlic juice for the purpose of garlic-Yackwa development. Five experimental groups containing 0 t.s, 1/2 t.s, 1 t.s, 1 and 1/2 t.s, and 2 t.s of garlic juice per 1 cup of flour were compared with basic group containing 2 t.s of ginger juice per 1 cup of flour (ginger-Yackwa), by Hunter's colorimetry, texture profile analysis and sensory evaluation. In Hunter's color value, Yackwa, substituted garlic juice from 1/2 t.s to 2 t.s per 1 cup of flour for ginger juice, were lower than ginger-Yackwa. The higher amounts of garlic juice in garlic-Yackwa showed the lower tendancy of L and a values. The b value of garlic-Yackwa containing from 0 t.s to 2 t.s of garlic juice was higher than that of ginger-Yackwa. The higher amounts of garlic juice in garlic-Yackwa showed the higher tendancy of b value. In the texture characteristics, hardness, adhesiveness, springiness and chewiness of all garlic-Yackwa were significantly lower than those of ginger-Yackwa. Cohesiveness of garlic-Yackwa containing from 1 t.s to 2 t.s of garlic juice was significantly higher than that of ginger-Yackwa. Gumminess of Yackwa with garlic juice was higher ($1_{1/2}$ t.s, 2 t.s) than that of ginger-Yackwa, or lower (0 t.s∼l t.s) than that of ginger-Yackwa. The higher amounts of garlic juice in garlic-Yackwa showed the higher tendancies of hardness, cohesiveness and gumminess, while springiness and chewiness showed vice versa. In sensory evaluation, the higher amounts of garlic juice in garlic-Yackwa showed the better color, appearance, flavor, taste and overall acceptability. Especially garlic-Yackwa with 2 t.s of garlic juice showed the best color, appearance, taste, overall acceptability among them. Garlic-Yackwa with 2 t.s of garlic juice evaluated the best, while ginger-Yackwa evaluated the worst. In conclusion, these results indicated that 2 t.s of garic juice per 1 cup of flour could be very useful as a substitute for ginger juice in developing garlic-Yackwa.

Adhesion Behavior of Chondrocyte and Osteoblast on Surface-Modified Biodegradable PLLA Films and Scaffolds (표면개질된 생분해성 PLLA 필름 및 지지체의 연골세포와 조골세포 점착거동)

  • Choi, Ji-Yeon;Jung, Hyun-Jung;Park, Bang-Ju;Joung, Yoon-Ki;Park, Kwi-Deok;Han, Dong-Keun
    • Polymer(Korea)
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    • v.36 no.3
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    • pp.357-363
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    • 2012
  • Surface-modified poly(L-lactic acid) (PLLA) films and scaffolds were treated with plasma discharge in oxygen gas and subsequently subjected to $in$ $situ$ grafting of acrylic acid (AA) in order to increase the cell compatibility. The surface of AA-grafted PLLA was converted to hydroxyapatite (HA)-deposited PLLA in stimulated body fluid (SBF). After the samples were immersed in phosphate-buffered saline (PBS), fetal bovine serum (FBS), normal saline, or cell medium, the water contact angles were significantly reduced on the surface of HA-deposited PLLA. Chondrocyte and osteoblast showed a higher attachment and cell proliferation on HA-deposited surfaces and in particular, it was confirmed that chondrocyte was considerably influenced by HA. However, osteoblast showed better cell proliferation on the surfaces immersed in FBS, cell medium or HA-deposited surface. In addition, the cell proliferation in 3D scaffolds was much higher than that on film type, irrespective of chondrocyte and osteoblast. Therefore, such surface-modified PLLAs are expected to be useful as organic-inorganic hybrid scaffolds in the regeneration of cartilage and bone.