• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.58-65
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• 1996

The effects of sodium carbonate (Na), potassuim carbonate (K) and their mixtures (Na/K=0.7-2.0) on pasting properties by amylograph and mixing properties by farinograph of wheat flour (9.45% protein), and of alkali mixtures (0.16%) on noodle property were examined. The concentrations of alkali used were 0.08%, 0.10% and 0.16% based on flour weight (14% mb). The salt (1.7%) and alkali decreased the initial pasting temperature but increased the amylograph peak viscosity. The peak viscosity increased with the increase of alkali concentration, but the mixing ratio at a fixed concentration had no effect on peak viscosity. The farinograph absorption decreased by salt, but the effect of salt diminished in the presence of alkali. The salt and alkali increased the farinograph stability, of which the former was more pronounced. The effect of alkali alone and mixtures in the presence of salt on amylograph and farinograph were essentially the same regardless the concentrations and mixing ratios. The yellowness and breaking force of dry noodle prepared with salt and alkali was higher than that prepared with salt only. The weight and volume gain of the optimum cooked noodle remained essentially constant, but the shear force and compression force were increased by the alkali.

• Applied Chemistry for Engineering
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• v.20 no.3
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• pp.339-345
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• 2009

The graft copolymerization of acrylonitrile-EPDM-styrene (AES) was investigated under various reaction conditions such as the concentration of initiator, the content of diene and viscosity of EPDM, and the concentration of solvents. The conversion increased but the molecular weight and the rubber particle size decreased with the concentration of initiator. The graft ratio(GR) increased at low concentrations of the initiator but, after the maximum value, it gradually decreased with the concentration of initiator. Toluene as a single solvent gave the highest conversion and the mixture of ethyl benzene and toluene was better than toluene. The rubber particle size increased with the viscosity of EPDM and the graft ratio and the number of rubber particles with occluded SANs increased with the content of diene.

• Journal of Korea Water Resources Association
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• v.50 no.5
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• pp.325-334
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• 2017

In this study, the numerical investigation of the non-linear behavior of the fluid flow with physical properties, such as porosity and intrinsic permeability of a porous medium, and kinematic viscosity of a fluid, are carried out. The applied numerical model is ANSYS CFX which is the three-dimensional fluid dynamics model and this model is verified through the application of existing physical and numerical results. As a result of the verification, the results of the pressure gradient-velocity relationship and the friction coefficient-Reynolds number relationship produced from this study show relatively good agreement with those from existing physical and numerical experiments. As a result of the simulation by changing the porosity and intrinsic permeability of a porous medium and the kinematic viscosity of a fluid, the kinematic viscosity has the biggest effect on the non-linear behavior of the fluid flow in the porous medium.

• Applied Biological Chemistry
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• v.32 no.4
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• pp.327-331
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• 1989

In this study the Theological properties between C1-treated soft wheat flour and untreated soft wheat flour was determined. Chlorine treatment lowered pH of the flour in a linear fashion. Water absorption and dough stability was high in proportion to the increase of treatment level but mechanical tolerance index was reduced by each increment of chlorine. The valorimeter value did not exhibit reproducible trend on treatment of chlorine. In general, resistance(BU), resistance to extension and maximum viscosity(BU) were highest in control group; lowest in 1 oz./cwt. flour and tended to rise in 2 oz./cwt. flour when it fermented in chamber for 90 min and 135 min. The maximum viscosity was highest (1,160BU) in 4 oz./cwt. flour and temperature at maximum viscosity tended to rise gradually in proportion to the increase of treated level.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.223-230
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• 1990

Gelatinization properties of heat-moisture treated Olchal(japonica) and Hankangchalbyeo(j x indica) waxy rice starches were compared. The blue value, light transmittance of starch suspension and viscosity in sodium hydroxide solution were similar between two starches. Olchal starch showed lower water binding capacity, swelling power md peak viscosity by amylograph than Hankangchalbyeo starch. Upon heat-moisture treatments all above parameters were decreased. The critical sodium hydroxide concentration for gelatinization was increased by treatments. The initial pasting temperature of Olchal starch was higher than that of Hankarlgchalbyeo. All amylograph reference points increased by the treatments, except the maximum viscosity or 2l% moisture-treated Olchal starch. Starches treated at 18% moisture level showd the highest value of consistency index. The activation energy of consistency index for gelatinized Olchal starch was lower than that for Hankangchalbyeo starch. The heat-moisture treatments had no effect on activation energy.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.8
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• pp.720-725
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• 2007

Cold acoustic tests have been performed to elucidate the effect of baffle gaps on the optimal damping characteristics in a liquid rocket combustor where coaxial injectors are installed. For several axial baffle lengths, an optimal acoustic damping capacitance has been achieved in a certain gap range. Cold acoustic tests for simulating fluid viscosity by changing the pressure in a model chamber have been done to study the main mechanism of optimal damping. Experimental data have shown that the optimal gap for high damping capacity exists mainly due to the viscosity near the gap of baffles. Therefore, axial baffle length can be reduced by using the optimal baffle gap, providing a possible solution of thermal cooling problems. Also, these optimum characteristics can be some guidelines for manufacturing and assembling injectors in full-scaled rocket combustors.

• Korean journal of food and cookery science
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• v.16 no.2
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• pp.151-159
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• 2000

The effects of bromelain and $\alpha$-chymotrypsin treatments on the functional properties(foaming capacity, foaming stability, emulsifying capacity, and emulsifying stability) of soy protein isolate(SPI) and the addition of various sweeteners(sucrose, sorbitol, xylitol) on the quality attributes(viscosity, overrun ratio, melt-down property, and sensory characteristic) of soy ice cream were studied. SPI was more effectively hydrolyzed with $\alpha$-chymotrypsin than bromelain, resulting in a better foaming and emulsifying capacity. Adding xylitol could significantly improve the viscosity, overrun and melt-down property of soy ice creams while the effect was the lowest in the sucrose addition. Bromelain treatment caused a lower apparent viscosity of SPI suspension compared with $\alpha$-chymotrypsin treatment and untreated. The overrun ratios of the soy ice cream prepared with bromelain and $\alpha$-chymotrypsin treated SPI were 18.9∼25.9% and 24.9∼40.3%, respectively as a result of freezing with agitation for 20 min in an ice cream maker. Comparatively, untreated SPI could bring only 15.8∼21.4% overrun ratios after operating for 15 min. The bromelain treatment caused high melt-down tendency of the product while soy ice cream with untreated SPI showed an opposite trend. In sensory characteristics, no significant differences in the strength of beany flavor were noted among the samples. Sweetness, bitter taste, icy feel, and mouthfeel of the product were greatly affected by the enzyme-treatment of SPI. Soy ice cream added with xylitol after $\alpha$-chymotrypsin treatment was the most acceptable among all samples.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.927-935
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• 2018

Various amounts of buckwheat powder (0%, 1%, 2%, and 3%) were added to emulsion-type pork sausages. The effects of buckwheat powder on the physicochemical characteristics of the emulsion type sausages, including proximate composition, cooking yield, viscosity, pH, instrumental color, texture profile analysis (TPA), and sensory evaluation, were determined. Increased levels of added buckwheat powder led to higher moisture (p<0.05), ash content (p<0.05 or >0.05), and cooking yield (p<0.05). However, the protein and fat contents of the sausage samples were lower (p<0.05) with higher levels of added buckwheat powder. The instrumental color and pH values were affected by the addition of buckwheat powder, which has a pH of 6.1 and associated color coordinates of $L^*=75.0$, $a^*=1.3$, and $b^*=8.7$. Meat batter with 3% buckwheat powder was shown the highest (p<0.05) viscosity indicating great formation of emulsion. There were no significant differences in the TPA among the treated samples. The viscosity value increased with increasing cooking yield in the batter ($r^2=0.7283$) i.e. the correlation coefficient between the two measurements was very high and positive. For sensory traits except for tenderness, the highest scores (p<0.05) was detected on sausages with 3% added buckwheat powder by a panel. These results suggest that the addition of 3% buckwheat powder to emulsion-type sausages produces a more beneficial meat product, with a lower fat content, greater formation of emulsion and no adverse effects on sensory properties.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.198-203
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• 1997

The ground persimmon puree was treated with two kinds of commercial polysaccharide hydrolyzing enzymes (Viscozyme and Celluclast) in order to study their effects on the extraction yield, viscosity, color, titratable acidity and sugars. Hydrolysis with Viscozyme which has enzymatic activity of arabinase, cellulase, xylanase, hemicellulase and ${\beta}-glucanase$ significantly increased the extraction yield, L-value and reducing sugar and decreased in viscosity by treatment for 10 min at $50^{\circ}C$. The extraction yield of the juice was increased from 42.7% to 80% by Viscozyme while the Celluclast to 73.3%. On the other hand, the sensory properties of persimmon-like flavor, scarlet and orange color were greatly improved for the juice hydrolyzed with Viscozyme for 60 min.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.53-59
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• 2011

The using of diesel engine will be increased in the world for fuel economy. But diesel engine emits harmful emissions such as much NOx, smoke etc. In this study, experiments were performed to investigate the spray characteristics of diesel spray in a common-rail system according to fuel temperature, injection pressure, injection period and fuel viscosity etc. using a high speed video camera. Diesel oil has different spray patten due to injection pressure and injection period in a common-rail system. A Filter pressure was influenced by fuel temperature which was turned to fuel viscosity related to a fluid flowing. The effect of the bio-diesel fuel mixing ratio on the spray and atomization characteristics was also investigated at various experimental conditions. It shows that the droplet atomization characteristics of bio-diesel fuel showed deteriorated results as the mixing ratio of biodiesel increased because of the high viscosity.