• Journal of Adhesion and Interface
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• v.11 no.3
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• pp.89-99
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• 2010

In this paper, for polymerization of poly(vinyl acetate-co-ethylene) (VAE) by redox system using poly(vinyl alcohol) (PVOH) as emulsifier on the properties of the final emulsion, and pH changes affect the physical properties of the final emulsion was investigated. The results of the molecular weight of PVOH had a dramatic impact on the emulsion properties. The used a low molecular weight of PVOH products was obtained low viscosity and using the high molecular weight of PVOH were obtained high viscosity product. However, changing the pH of the final polymerized product properties for the PVOH obtained different results. Generally, a poly(vinyl acetate) emulsion by a high degree of polymerization and high molecular weight of PVOH was obtained high viscosity of the final emulsion. But, in VAE was lower emulsion viscosity in high pH. This is the molecular weight of the emulsion during the synthesis of PVOH is considered to be affected by degradation. The final viscosity was decreased by grafting ratio and molecular weight were decreased with increasing of pH.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.783-788
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• 2007

An advantage to the extrusion of raw potatoes is a reduction in the energy input required to process potato products; however, the effects of extrusion on the properties of raw potato have not been studied. The purposes of this study were to develop a workable extrusion process for raw potato and to study the effects of extrusion conditions on the pasting properties of extruded potato products. The peak viscosity, final viscosity, pasting temperature, water solubility index, and water absorption index of pressed and pressed-dried potato extrudates decreased as die exit temperature increased, whereas they did not change as screw speed increased. The peak viscosity, final viscosity, and water solubility of steam-cooked potato products decreased with extrusion processing; however, they did not change with increasing die exit temperature and screw speed. Potato products with different degrees of depolymerization of extruded potato starch, depending on die exit temperature, were produced from raw potatoes.

• International Journal of Highway Engineering
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• v.19 no.4
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• pp.19-25
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• 2017

PURPOSES : In this paper, the flow of construction material was simulated using computational fluid dynamics in a 2D axisymmetric condition to evaluate the effect of initial or varying material properties on the final shape of a specimen. METHODS : The CFD model was verified by using a well-known analytical solution for a given test condition followed by performing a sensitivity analysis to evaluate the effect of material properties on the final shape of material. Varying dynamic viscosity and yield stress were also considered. RESULTS : The CFD model in a 2D axisymmetric condition agreed with the analytical solution for most yield stress conditions. Minor disagreements observed at high yield stress conditions indicate improper application of the pure shear assumption for the given material behavior. It was also observed that the variation of yield stress and dynamic viscosity during curing had a meaningful effect on the final shape of the specimen. CONCLUSIONS : It is concluded that CFD modeling in a 2D axisymmetric condition is good enough to evaluate fluidal characteristics of material. The model is able to consider varying yield stress and viscosity during curing. The 3D CFD-DEM coupled model may be required to consider the interaction of aggregates in fluid.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.4
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• pp.81-87
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• 2015

Soda-AQ pulp made from sugarcane bagasse (SCB) were bleached in element chlorine free (ECF) sequence. To reduce chlorine dioxide use, final peroxide bleaching was introduced. Prior to peroxide bleaching, different chelating chemicals were applied for comparative analysis in ISO brightness and viscosity. When using equal total chlorine dioxide usage (4.5%), bleached SCB pulp using chelate and hydrogen peroxide (DEDQP) was reached 86.8% (DTPA), 86.4% (EDTA) ISO brightness, whereas bleached pulp using only hydrogen peroxide (DEDP) reached at 81.2% ISO brightness. Viscosity of DEDQP bleached pulp was 25.6 cPs (DTPA), 25.2 cPs (EDTA), And DEDP bleached pulp was shown 18.0 cPs viscosity. Decreasing of transition metal by chelate process led to improvements in final brightness along with higher viscosity. Due to EDTA is 5-7 times cheaper than DTPA, EDTA is recommended as chelating chemical prior to peroxide bleaching.

• Journal of the Korea Concrete Institute
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• v.11 no.6
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• pp.69-78
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• 1999

Hydroxyethyl cellulose -based-viscosity modifying admixture and melamine-basd-superplasticizer were selected to be admixtures for self-compacting concrete based on the test results of fluidity and air content of mortar using 3 different viscosity modifying admixtures. The experimental results show that the initial and final set of self-compacting concrete and fly ash concrete with viscosity modifying admixture only have been delayed approximately 5 hours and 8~9 hours, respectively. It is found that the optimum dosage of viscosity modifying admixtures, coarse aggregate and cement content are 0.2% of water content, under 742 kg/$\textrm{m}^3$ and over 364 kg/$\textrm{m}^3$, respectively. Test results also show that the optimum fly ash in replacement of cement is 10% of cement weight for the enhancement of fluidity and long-term strength.

• Culinary science and hospitality research
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• v.8 no.3
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• pp.267-278
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• 2002

To promote the consumption of race, comparative study was performed on characteristics of wheat flour noodle mixed with brown rice flour and colored rice flour. Protein content of colored rice was higher than that of the brown rice, but lipid and ash contents were similar to those of brown rice. Colored rice flour had significantly lower peak viscosity, holding viscosity, breakdown viscosity, final viscosity and setback viscosity than those of wheat flour, while brown rice had significantly higher peak viscosity, breakdown viscosity and setback viscosity than those of colored rice flour and wheat flour. Colored rice and brown rice had 5.3~6.4% total dietary fiber, and the proportions of soluble fiber in total dietary fiber were quite low, ranging from 9.4% to 18.8%. L(brightness), a(redness) and b(yellowness) of raw noodles were measured using a colorimeter. L(brightness) and b(yellowness) values of Asian raw noodles made from colored rice and brown rice significantly decreased. Addition of colored rice flour and brown rice flour to Asian noodle reduces cutting forces of dry and cooked noodles. The cooked noodle with 10% chalheukmi waxy rice flour was the highest in the cutting force of cooked noodle. Addition of 20% chalheukini waxy rice flour and 20% brown rice flour to wheat flour was got to a relatively high score for appearance, color, texture, taste and overall eating quality from sensory evaluation of cooked noodles.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1407-1413
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• 2015

The objective of this study was to investigate the rheological and pasting properties of potato flour dispersions at different concentrations (3, 4, 5, 6, and 7%, w/w). A potato cultivar 'Goun', used in this study, was developed by Highland Agriculture Research Center, RDA. Potato flour dispersions showed shear-thinning behaviors (n=0.44~0.51) at $25^{\circ}C$. Apparent viscosity (${\eta}_{a,100}$), consistency index (K), and yield stress (${\sigma}_{oc}$) significantly increased with an increase in potato flour concentration. Storage modulus (G') and loss modulus (G") significantly increased, whereas complex viscosity (${\eta}^*$) was significantly reduced with increasing frequency (${\omega}$) from 0.63 to 63.8 rad/s. Magnitudes of G' and G" were significantly increased with elevation of potato flour concentration. G' values were considerably greater than G" over the entire range of frequency (${\omega}$) with a high dependence on ${\omega}$. Cox-Merz rule was not applicable to potato flour dispersions. Rapid Visco Analyzer data showed that peak viscosity, trough viscosity, breakdown viscosity, final viscosity, and set back viscosity of samples significantly increased with an increase in potato flour concentration.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1291-1297
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• 2000

Particle size distribution, pasting properties by Rapid Visco Analyser, and textural properties of acorn, mungbean and buckwheat starches, which are the basic raw materials for mook, are compared. The major particle size of mungbean starch was $10{\sim}30$ micron, whereas acorn and buckwheat starches were $5{\sim}20$ micron. At the same starch concentration, mungbean starch had the highest peak viscosity, breakdown and setback. Acorn starch showed the lowest peak viscosity and breakdown. The peak viscosity of buckwheat starch was close to that of mungbean, however the trough and final viscosity were comparable to those of acorn starch. At the same peak viscosity, mungbean starch showed the lowest trough and final viscosity and the highest breakdown and setback. Acorn starch was differentiated from buckwheat starch in that the former had the higher value of setback. The textural properties of mungbean starch gel were significantly different from others. The texture of gels from acorn and buckwheat starches revealed that only the hardness and gumminess were different each other. The hardness of starch gels were negatively correlated with trough and final viscosity, and positively correlated with setback.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.186-190
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• 2005

This experiment was conducted to collect the basic information on the varietal diversity in amylogram properties of 3 different rice sub-species under tropical conditions in IRRI 2001 wet season based upon correlation and principal component analysis. The peak viscosity and breakdown property of Tongil type, i.e.; temperate Indica species showed higher similarity with Japonica type species rather than typical Indica and tropical japonica types. The amylogram properties such as final viscosity, pasting consistency and setback of Tongil type varieties were lower than those of typical Indica and tropical japonica types. The peak viscosity showed positive correlation with trough, while the breakdown showed negative correlation with setback in all tested 3 rice subspecies. The first principal component was applicable to increase the gelatinization temperature, final viscosity, pasting consistency and setback, and applicable to decrease the peak viscosity and breakdown. Varietal classification by the principal component score of each pedigree could be applied to the interpretation of the community by the scatter diagram for the amylogram properties to the different sub-species of rice at IRRI conditions.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.855-860
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• 2009

Physicochemical properties of starches isolated from 3 new potato cultivars developed by Potato Valley Ltd. were investigated and compared to those of starch isolated from 'Superior' being distributed prominently in Korea. Significant differences were observed in physicochemical properties such as granule size, amylose content, phosphorus content, water binding capacity, swelling power, solubility, and in vitro digestibility of starches from different potato cultivars. Thermal properties were evaluated using differential scanning calorimetry (DSC), and onset gelatinization temperatire ($T_o$), peak temperature ($T_p$), and enthalpies of gelatinization (${\triangle}H$) of different potato cultivars ranged as $58.0{\pm}0.3-61.7{\pm}0.4^{\circ}C,\;63.7{\pm}0.2-$ $66.5{\pm}0.0^{\circ}C$, and $15.6{\pm}0.5-17.0{\pm}0.3$ J/g, respectively. Pasting properties were evaluated using a rapid visco analyzer (RVA), and pasting temperature, peak viscosity, and final viscosity of different potato cultivars ranged as $65.0{\pm}0.1-68.9{\pm}0.1^{\circ}C$, $8,163.7{\pm}196.3-9,035.7{\pm}6.4$ cp, and $4,397.7{\pm}166.7-7,025.0{\pm}271.3$ cp, respectively. Especially, 'Gogu valley' starch showed the highest values in the amylose and phosphorus content among tested potato cultivars and higher water binding capacity, swelling power, and solubility than those of other tested starches. And it also showed high pasting temperature, peak viscosity, trough viscosity, and final viscosity as compared to other tested starches.