• Korean journal of food and cookery science
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• v.19 no.1
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• pp.65-71
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• 2003

The objective of this study was to compare the textural properties and sensory evaluation of Injulmi, a traditional Korean waxy rice cake, added with 10, 20 and 30% of RS3-type resistant starch. RS3-type resistant starch was prepared from nonwaxy rice(Odaebyeo) starch by autoclaving-cooling cycle. The RS yield of RS3-type resistant starch was 9.10%. By increasing the addition level of RS3-type resistant starch, the hardness and adhesiveness of Injulmi increased as measured by using a rheometer. Hunter color L and a values of Injulmi added with RS3-type resistant starch were increased, but b value was decreased. In case of sensory evaluation, the hardness of Injulmi added with RS3-type resistant starch was higher than that of non-added Injulmi. The overall duality of Injulmi added with RS3-type resistant starch by sensory evaluation was negatively correlated with the hardness measured by rheometer(p＜.0.05).

• Korean Journal of Human Ecology
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• v.3 no.2
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• pp.68-76
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• 2000

The quality of Injulmi, waxy rice cake is affected by milling methods. varieties. additives, steeping condition before milling and the texture properties during storage. Sinsunchalbyeo and Hwasunchalbyeo flours were made using pin-dry milling(PDM) and roller-wet milling( RWM) methods. Injulmi was made from those flours with different sugars, sucrose, maltose. oligosaccharide, and were measured textural properties of Injulmi stored at 2 $0^{\circ}C$ for 0, 12, 36 and 60 hrs, respectively. The hardness of sucrose added to injulmi made from PDM flour was the highest among any other sugars, but Injulmi from RWM flour was increased in the following order sucrose>maltose>oligosaccharide>non - added Injulmi. Adhesiveness of none added Injulmi were the lowest among sugar added Injulmi including, oligosaccharide, maltose and sucrose added Injulmi.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.1
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• pp.34-43
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• 1990

Six commerical rice varieties were cultivated and harvested at different locations in 1987 and 1988 to clarify the degree of locational variations. of several characteristics related to rice grain quality using the rice samples harvested from 8 to 20 locations for a variety each year. Locational variations of percent brown rice, percent milled rice, 1000-grain weight and amylose content were small, but whole grain rate, alkali digestibility, gel consistency, percent white-center and white-belly grain, degree of chalkiness and degree of translucency showed larger variations between locations. The degree of locational variation of sensory evaluation score for eating quality of cooked rice were varied from small to large along with rice variety used and year cultivated. Texture palatability index and stickiness of cooked rice among rheogram characteristics showed larger locational variations, but cohesiveness and springiness showed smaller variations between locations. Set back, break down and maximum viscosity showed larger locational variations among amylogram characteristics of rice flour. Special attention was given to a cultivated location, Anseong, because rice samples harvested at Anseong showed lower percent white-center and white-belly grain, and low set back and high break down in Chucheongbyeo, lower percent white-center and white-belly grain, higher texture palatability index and viscousness/hardness ratio, and low set back and high break down in Dongjinbyeo, higher texture palatability index, and low set back and high break down in Yongmunbyeo, lower percent white-center and white-belly grain in Sangpungbyeo, and low set back and high break down in Samkangbyeo. No other locations in this study produced rice samples showing wide acceptable quality-related characteristics except Anseong.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.311-320
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• 2018

The purpose of this study is to evaluate the flow ability of the thermoplasticized Gutta Percha in different temperatures. Four Gutta Percha products were classified by its hardness (soft, medium, and hard) and were experimented by the Rheometer (Melt flow indexer MFI-10, DAVENPORT, England) measuring apparatus, in $(23{\pm}2)^{\circ}C$, and in a relative humidity of ($50{\pm}5$) %, following the guidelines of ISO 1133-1:2011. The heating temperature ranged from $108^{\circ}C$, $160^{\circ}C$ to $200^{\circ}C$, and the load at 2.16 kg and 3.8 kg. The Gutta Percha was cut in 5 mm to be suitable for the rheometer pressurization process. After the experiment was conducted with a preheating time of 5 minutes, a cutting time of 5-240 seconds, and a sample of 10 grams, the Gutta Percha did not show any changes in fluidity for $108^{\circ}C$, $160^{\circ}C$, but showed a change in its flow ability in $200^{\circ}C$. Also, the Gutta Percha did not show any changes in its fluidity when it was pressurized by 2.16 and 3.8 kilograms. Therefore, this experiment shows that the heating temperature and the cut-off time showed a significance while measuring the melt flow rate.

• Elastomers and Composites
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• v.45 no.2
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• pp.122-128
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• 2010

We measured shear viscosity of copoly(styrene(St)/butyl methacrylate(BMA)) (co-PSB) particles, with a capillary rheometer at $170^{\circ}C$, prepared by suspension polymerization with hydrophobic silica as a stabilizer. co-PSB particles with the weight average molecular weights of lower than 74,800 g/mol displayed a Newtonian behavior at low shear rates. With the weight average molecular weight exceeding 136,800 g/mol, co-PSB particles showed shear thinning against shear rates and the absolute value of the slopes between shear viscosity vs. shear rate increased. When the ratio between St and BMA changed from 7/3 to 5/5 to 3/7, shear viscosity and glass transition decreased despite similar molecular weights. When the ratio was 1/9, it showed a large increase in initial shear viscosity despite reduced glass transition. Shear viscosity exhibited an increase in proportion to carbon black concentration. The effect of carbon black concentration on the shear viscosity of co-PSB composites was less pronounced compared to varying molecular weights and/or compositional ratio.

• Journal of the Korean Ceramic Society
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• v.39 no.11
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• pp.1090-1096
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• 2002

Six different composition of water-swellable bentonite rheology modifiers(WSB-1~WSB-6) were prepared by the compounding of peptizers and anionic surfactants as an additives with Bentonite(BEN) of montmorillonite group. Average particle size, particle morphology and water-swellability of WSB and the viscosity with additives were measured, respectively. And the rheological behavior of WSB were investigated using the rheometer. The viscosity of WSB-1 increased with decreasing both pH and average particle size of BEN, WSB-2 treated $Na_2CO_3$ as a peptizer showed the maximum viscosity. These results can be interpretated cause for rearrangment as the edge-to-face structure of BEN particles containing WSB. Also, WSB-4∼WSB-6 containing both peptizer and anionic surfactant was sol phase that their viscosity was not nearly with the shear rate, however, WSB-3 containing Tetrasodium Pyrophosphate(TSPP) as an anionic surfactant showed the thixotropy by the viscosity difference of 1000 times with the shear rate. From this result, the anions of TSPP can be explained to arrange in edge of BEN particles containing WSB-3.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1897-1905
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• 2013

Rheological properties such as yield stress and viscosity is the main parameters to determine the fluidity of the debris flow. In this study, several series of rheometer tests were performed to investigate rheological properties of fine-grained soil samples with various sand contents and various liquidity indices. Test results indicated that the general shape of the flow curves for fine-grained soils had characteristics of a shear thinning fluid, with a decrease in viscosity as shear rate increases. The yield stress and viscosity of fine-grained soil samples with same sand content gradually decreased as the liquidity index increased. At the same liquidity index, yield stress and viscosity of fine-grained soil increased with an increase in sand content. The yield stress and viscosity of fine-grained soil greatly decreased with a slight increase in water content. Also, the yield stress and viscosity tend to increase with increasing concentration by volume($C_v$) of the fluid matrix. The values of the four coefficients ${\alpha}_1$, ${\alpha}_2$, ${\beta}_1$, and ${\beta}_2$ were obtained by regression analysis for each fine-grained soil.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.417-422
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• 2003

Addition of whole soy flour(WSF) to wheat flour(WF) was studies for its effects on dough and noodle characteristics. The WF used was medium grade of strength and WSF was a fine flour of 350 mesh. The addition ratio of WSF to. n was up to 20%. The dough properties and textural properties of wet and cooked noodles were measured with using Farinograph, Amylograph and Rheometer. Farinogram data showed the minimum dough development time and stability at 6% addition of WSF. Amylograph data of initial pasting temperature and time were increased while the maximum and final viscosity and setback were decreased as the WSF added more to W The initial pasting temperature of 2.0∼6.0% WSF added flour were comparable to 100% WF eventhough viscosity was almost half of WF. The water absorption capacity was increased from 81.6% to 92.3% at 6.0% WSF and then decreased as the addition ratio of WSF increased. The extensibility of dough showed a maximal value at 8.0% WSF addition. Strengthness and hardness of wet and cooked noodle were increased to the heighest measurement as the WSF added up to 6.0% followed by a steady decrease thereafter. It was also found that WSF addition resulted an increase in adhesiveness of wet noodle and decrease in hardness and strengthness of cooked noodle.

• Polymer(Korea)
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• v.35 no.1
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• pp.23-29
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• 2011

We measured shear viscosity of polymeric particles, prepared by suspension polymerization with hydrophobic silica as a stabilizer at $75^{\circ}C$, by a capillary rheometer. Shear viscosity displayed a non-Newtonian behavior with an increase in weight average molecular weight. Measurement of shear viscosity at 170 and $190^{\circ}C$ with copoly(styrene/butyl methacrylate) (co-PSB) particles by varying the ratio between styrene (St) and butyl methacrylate (BMA) showed that shear viscosity was a function of molecular weight, temperature and compositional ratio. When the ratio was 7/3, 5/5 and 3/7, shear viscosity slightly reduced with an increase in BMA concentration despite similar weight average molecular weights. We found that shear viscosity of copolymers with BMA concentrations exceeding 70% displayed a sharp reduction at high shear rates. It is speculated that increased PBMA chain length contributes to enhanced flowability of copolymers. When carbon black was incorporated into co-PSB, shear viscosity progressively increased with increasing carbon black concentration. The increase in shear viscosity, however, was less pronounced compared to the cases of molecular weight increase.

• Elastomers and Composites
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• v.44 no.3
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• pp.336-342
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• 2009

We measured shear viscosity of polystyrene (PS) and poly(butyl methacrylate) (PBMA) particles, with a capillary rheometer, prepared by suspension polymerization with 1.0 wt% hydrophobic silica as a stabilizer by varying the initiator concentration at $75^{\circ}C$. PS particles with weight average molecular weight of 66,500 g/mol displayed a Newtonian behaior at low shear rates at $190^{\circ}C$. With increasing molecular weight, PS particles showed shear thinning over the entire range of shear rates. For PBMA particles, steady shear measurement was carried out at $170^{\circ}C$. PBMA particles with weight average molecular weight of 156,700 g/mol showed a Newtonian behaior only at low shear rates. PBMA particles also showed shear thinning with an increase in molecular weight and its pattern similar to that of PS. When carbon black was incorporated into PS and PBMA polymers, steady shear measurement was conducted at $170^{\circ}C$. An increase in carbon black concentration in PS and PBMA composite particles exhibited a progressive increase in shear viscosity. The increase in shear viscosity, however, was less pronounced compared to an increase as a function of molecular weight. Preparing PS composites containing carbon black by internal mixing resulted in an increase in shear viscosity. Its increase, however, was found to be less than that shown in PS composite particles. We speculate that this is caused by an enhanced dispersion of carbon black particles with an internal mixer. Yield behavior was not observed in any of the samples we selected in this experiment.