• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.505-512
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• 2016

Even though high performance concrete was developed according to the trend of bigger and higher of reinforced concrete building, the rheological evaluations such as viscosity, yield stress are not enough to use as input data to accomplish the numerical analysis for the construction design. So there are many problems in the harden concrete such as poor compaction, rock pocket and crack, etc. in the field. In this study, consistency curves were measured by the viscometer as hydration reaction time passed. At the same time the slump flow test and Vicat setting test were carried out for comparing with the results of rheological properties. The fluidity of the W/B 30% decreased as the increase of replacement ratio of blast furnace slag. But in case of W/B 40%, the replacement ration did not significantly influenced to the slump flow value with the passage of hydration time. By the replacement of blast furnace slag to cement, initial setting was delayed and the time gap between initial and final setting became shorten. Through the regression analysis using Bingham model, there are a sudden changes of viscosity and yield stress around initial setting in case of low W/B 30%. The increase of workability by the change of free water in cement paste was offset by the coating effect of impermeable layer in case of W/B 40%.

• Culinary science and hospitality research
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• v.19 no.4
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• pp.119-135
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• 2013

This study investigates waxy barley powder substituted for wheat flour in bread recipes with the amounts of 0%(control), 5%, 10%, 15% and 20%. Waxy barley powder consisted of 8.33% of moisture content, 10.47% of crude protein, 1.63% of crude fat, and 2.97% of crude ash. Sedimentation value and pelshenke value have decreased as the waxy barley powder content increased. The farinograph measurement result of the bread made with waxy barley powder showed that consistency, water absorption, development time, stability and time breakdown have increased as the waxy barley powder content increased. The amylograph measurement result of the bread made with waxy barley powder showed that T have increased as the waxy barley powder content increased. Their P, H and P-H have decreased as the ingredient contents increased. Baking loss and specific loaf volume have decreased as the waxy barley powder content increased. The chromaticity measurement result of the bread made with waxy barley powder showed no significant difference as the waxy barley powder content increased. The texture measurement result showed that the hardness and gumminess of bread have increased as the waxy barley powder content increased. Their cohesiveness, springiness and chewiness have decreased as the ingredient contents increased. Overall preference scores showed a high acceptability for the bread made with 10% waxy barley powder.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.534-542
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• 2006

The protein contents of soy protein isolate (SPI) and soft wheat flours were 83.5% and 8.5%, respectively. The addition of SPI increased the protein content but decreased the sedimentation value. Alkaline water retention capacity (AWRC) value increased with SPI addition and was highly correlated with protein content. Increasing SPI flour content significantly decreased the maximum, minimum and final viscosities. Mixograph peak time was positively correlated with protein content and AWRC. The PH and specific gravity of the cake batter increased with increasing SPI content. The SPI addition reduced the loaf and specific loaf volume compared with soft wheat flour. The lightness of the cake crust decreased, while the redness and yellowness increased, with SPI flour addition. SPI addition resulted in a decrease of overall acceptability, but an increase in hardness.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.348-354
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• 2006

Baking quality of dough made of flour substituted with insoluble ${\beta}-glucan$ (10, 20, and 30%), functional food material produced from Agrobacterium spp. R259 KCTC 10197BP, was evaluated. Optimum time to reach 1st stage of dough fermentation decreased with increasing ${\beta}-glucan$ content, whereas mixing time increased. Addition of ${\beta}-glucan$ did not affect pH of dough. Hunter color L, a, and b values of dough added with up to 20% ${\beta}-glucan$ were not significantly different from those of control. Rheology properties such as cohesiveness and springiness of ${\beta}-glucan$ added dough increased, while hardness and gumminess decreased. Amylogram showed addition of ${\beta}-glucan$ to flour lowered setback and consistency, which are suggested to delay retrogradation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.1
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• pp.59-62
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• 2004

To know what happens to the internal structure of emulsions under high shear flow is very important for cosmetic product development because it is highly relevant to the physical degradation of emulsions during the application upon the skin. Here, in order to investigate the response of emulsions against the external shear forces, we designed a new device, .JELLI$^{TM}$ (Joint Electro-rheometer for Liquid-Liquid Inversion) chip, for the measurement of electrical and rheological properties of emulsions under shear flow. By using this device, we examined the real-time changes in conductivities of oil-in-water (O/W) and water-in-oil (W/O) emulsions on the artificial skin during large deformation under shear flow. In this study, O/W and W/O emulsions having various volumes were prepared. After emulsions were homogeneously applied on the artificial skin, the electrical resistance and viscosity changes were monitored under steady shear flow. In case of O/W emulsions, the resistance increased as a function of time. The resistance showed more dramatic increase as the increase of the internal oil phase. It was also found that the viscosity change was proportional to the resistance variation. This phenomenon might be caused by decreased resisting forces against the shear flow because of the breakdown of the internal phase.the internal phase.

• Polymer(Korea)
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• v.26 no.2
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• pp.218-226
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• 2002

For the preparation of high resilience polyurethane (PU) foams with polyether type cell openers which have different ethylene oxide (EO) content, molecular weight and chain structure, the influences of tell opener structure on the kinetics, rheology, structural stability, open cell content and mechanical properties of the obtained foam were investigated. It was observed that urea formation reaction was delayed with the increase of EO content and incorporation of ester linkage in cell opener molecule and was relatively independent on the molecular weight. With the rheological studies, the decreases of viscosity and storage modulus were confirmed for the increase of EO content and molecular weight, so that the resulted foam had low structural stability and high open cell content. The cell opener having ester linkage in molecule exhibited the lowest values of viscosity and storage modulus and the obtained foam has high open cell content. However, the structural stability increased due to the larger intermolecular interaction of ester linkage. The hardness, tensile strength, tear strength and elongation of foam were deteriorated with increase of EO content and molecular weight of tell opener. On the other hand, the cell opener having ester linkage in molecule improved the values of tensile strength, tear strength and elongation.

• Polymer(Korea)
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• v.30 no.1
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• pp.85-89
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• 2006

The effect of vapor grown carbon fiber (VGCF) contents on electrical and rheological properties of VGCF filled polyphenylene sulfide (PPS) composites prepared through melt mixing using a twin screw exruder was studied. This method was proved to be quite effective to produce good dispersion of VGCF in the matrix even for highly filled PPS. From the dependence of the electrical conductivity on VGCF content, the percolation phenomena began to occur above $10\;wt\%$. While there is only a marginal increase of viscosity for 1 and $5\;wt\%$ VGCF filled PPS, the composites containing $10\;wt\%$. While VGCF showed abrupt increase in viscosity as well as flattening of frequency vs modulus curve, indicating a transition from a liquid-like to a solid-like behavior due to the creation of VGCF network. This result agrees well to the fact that the network formation in the composite can be composite by rheological property dependence on filler content as well as by electrical conductivity measurement.

• Food Science of Animal Resources
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• v.32 no.6
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• pp.803-809
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• 2012

This study was carried out to evaluate the effects of whey ferment containing L. acidophilus KCCM 32820 and P. freudenreichii KCCM 31227 on the quality characteristics of white pan bread. Instrumental analysis such as alveograph, gelatinization temperature, texture analysis, retrogradation rate was determined. In an alveograph test, $P_{max}$ value in the treatment was higher than that in the control, but extensibility of dough in the control showed to be higher than in the treatment, so test dough showed more strength than the control. In terms of DSC analysis for gelatinization, temperature there were no significant differences of $T_p$ and ${\Delta}H$ between the control and the treatment. In hardness analysis by rheometer, dough containing whey ferment revealed lower values than the control. From the analysis of the organic acid contents, propionic acid was not detected in the control, however 1.13 mg/g of propionic acid was detected in the treatment. In the retrogradation analysis by DSC, the test delayed slightly compared to the control.

• Proceedings of the KACD Conference
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• 2008.05a
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• pp.235-245
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• 2008

The aim of this study was to develop a method for measuring the slumping resistance of resin composites and to relate it to the rheological characteristics. Five commercial hybrid composites (Z100. Z250. DenFil, Tetric Ceram. ClearFil) and a nanofill composite (Z350) were used to make disc-shaped specimens of 2 mm thickness. An aluminum mold with square shaped cutting surface was pressed onto the composite discs to make standardized imprints. The imprints were light-cured either immediately (non-slumped) or after waiting for 3 minutes at $25^{\circ}C$ (slumped). White stone replicas were made and then scanned for topography using a laser 3-D profilometer. Slumping resistance index (SRI) was defined as the ratio of the groove depth of the slumped specimen to that of the non-slumped specimen. The pre-cure viscoelasticity of each composite was evaluated by an oscillatory shear test and normal stress was measured by a squeeze test using a rheometer. Flow test was also performed using a flow tester. Correlation analysis was performed to investigate the relationship between the viscoelastic properties and the SRI. SRI varied between the six materials (Z100 < DenFil < Z250 < ClearFil < Tetric Ceram < Z350). The SRI was strongly correlated with the viscous (loss) shear modulus G' but not with the loss tangent. Also. slumping resistance was more closely related to the resistance to shear flow than to the normal stress. Slumping tendency could be quantified using the imprint method and SRI. The index may be applicable to evaluate the clinical handling characteristics of composites.

• Korean Journal of Food Science and Technology
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• v.15 no.3
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• pp.269-276
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• 1983

Experiments were performed to study the rheological and baking properties of bread fortified with various amounts of filefish protein concentrate (FPC). Doughs were prepared from mixtures containing wheat flour and 5,10,15 and 20% of FPC. Standard methods were used to evaluate the rheology of doughs and characteristics of bread. The results were as follows. 1. The water absorption of the fortified doughs increased as FPC increased. FPC caused an increase in development time and stability as measured by Farinograph. 2. In the extensigraph test, FPC yielded a decrease in extensibility and an increase in resistance to extension. 3. Baking tests demonstrated that addition of FPC decreased the volume of loaf and made the crumb darker and coarser. 4. Additional tests were made to examine effect of sodium stearoyl lactylate (SSL) added at 0.25, 0.50, 1.00 and 2.00% on doughs containing 10% headed & gutted FPC. The most appropriate amount of SSL as an additive was 0.5%. 5. In the farinograph, adding 0.5% SSL could delay dough development time and greatly increase stability. 6. When 0.5% SSL was added on doughs containing 5,10,15 and 20% headed & gutted FPC, baking quality was greatly improved. The breads containing up to 10% were acceptable by the addition of SSL, but not in higher level of FPC. 7. The results of sensory evaluations of bread showed that the color, texture and taste of bread containing 5% whole FPC and 5, 10% headed & gutted FPC were reasonably gacceptable.