• Journal of Power System Engineering
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• v.13 no.2
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• pp.30-35
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• 2009

Numerical Calculations for dimensionless pressure drop (friction factor times Reynolds number) have been obtained for fully developed laminar flow of MPL(Modified Power Law) fluid in isosceles triangle pipes. The solutions are valid for Pseudoplastic fluids over a wide range from Newtonian behavior at low shear rates through transition region to power law behavior at higher shear rates. The analysis identified a dimensionless shear rate parameter which for a given set of operating conditions specifies where in the shear rate range a particular system is operating, i.e., Newtonian, transition or power law region. The numerical calculation data of the dimensionless pressure drop for the Newtonian and power law regions are compared with previously published asymptotic results presenting within 0.16 % in Newtonian region and 2.98 % in power law region.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.2
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• pp.68-72
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• 2007

The flow properties of sulfated polysaccharides purified from the ascidian Halocynthia roretzi tunic were investigated. The sulfated polysaccfarides produced aqueous solutions of low apparent viscosity with pseudoplastic flow behavior. The respective activation energies of TCA-treated and TCA-nontreated solutions were $2.2248{\times}10^4\;and\;1.442{\times}10^4J/kg{\cdot}mol$ at a 150L/s shear rate. The viscosity of the sulfated polysaccharides solution was increased by the addition of sugar, while it was not changed by the addition of NaCl.

• The Korean Journal of Food And Nutrition
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• v.13 no.1
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• pp.78-82
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• 2000

For the purpose of investigation of the food processing fittness of the sea mustard aqueous extracts, the steady shear flow have been measured over a wide range of shear rate using a Brookfield digital viscometer(SPDL21). The rheological behaviors of the sea mustard aqueous extracts which were extracted at 10$0^{\circ}C$ for 2 hours exhibited pseudoplastic behavior with yield stress. In the test of the relationship between temperature and apparent viscosity of samples at 10 rpm decreased along with the increment of temperature. The sea mustard aqueous extracts appeared greatly temperature dependent characteristics(Ea=1.51 ㎉/mole).

• Journal of the Korean Ceramic Society
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• v.34 no.11
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• pp.1173-1181
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• 1997

Effects of particle size distribution of alumina ceramics on behaviors of tape casting were investigated with emphases on the rheological characteristic of slurry, green density, green sheet strength, and sintering density. For the control of particle size distribution of alumina, the commercial grade low soda alumina, which had different mean particle size of 3.58 ${\mu}{\textrm}{m}$ and 0.42 ${\mu}{\textrm}{m}$, were chosen and blended together. As results, the mixing of 80 wt% fine powder and 20 wt% coarse powder(designated to FC20) led to the increase of packing density and strength of green sheet, and made it easy to handle during processing without lowering of sintering density. Besides, the pseudoplastic behavior of slurry decreased with increase of the fraction of coarse alumina powder.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.808-811
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• 2001

The rheological properties of exopolysaccharide(EPS-R) produced by marine bacteria Hahella chjuensis KCTC 2395 was investigated. EPS-R solution showed a characteristic non-Newtonian behavior fluid properties. In aqueose dispersions of EPS-R 1%, consistency index(K) and flow behavior index(n) were 1,410 cp and 0.73. EPS-R solution was pseudoplastic fluid by power-low model. Rheological propertie of EPS-R was found to be influenced by the concentration of salt, pH, temperature and ionic compounds.

• Journal of Food Hygiene and Safety
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• v.5 no.1
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• pp.35-40
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• 1990

As a link in the studies on the extracellular polysaccharide by lactic acid bacteria, the experiment was conducted to investigate the viscosity variations and rheological properties of 10% reconstituted skim milk and 12% reconstituted whole milk, respectively. 1. 10% reconstituted skim milk cultured by Str. thrennophilus 510 showed strong flow property of pseudoplastic fluid depending upon the production of exopolysaccharide. And the viscosity reached the highest value within 14% concentration. 2. 12% reconstituted whole milk cultured by lactic acid bacteria indicated flow property of pseudoplastic fluid. But there was a big difference in the viscosity as compared with 10% skim milk. 3. The maximum consistency index (k) and the minimum flow behavior index (n) of the fermented milk by Str. thermophilus 510 were 43 and 0.09, respectively. They were 35 and 0.09, in case of Lb. bulgaricus.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.198-203
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• 2000

A highly viscous biopolymer from Bacillus coagulans CE-74 was purified and its rheological properties were studied The rheological properties of biopolymers produced by Bacillus coagulans CE-74 were studied at the temperature ranges with 20~8$0^{\circ}C$, at the concentration of 0.5~4.0%, at the pH ranges from 3 to 1 and at the shear rate fo 7.34~73.38 sec-1. The apparent viscosity of biopolymer was decreased with increasing shear rate, and thereby biopolymer showed pseudoplastic characteristics. Biopolymer solution showed a characteristic of non-Newtonian fluid properties. At the concentration of 1%, the consistency index and the flow behavior index were shown at 2.64 poise. sec11 and 0.8571, respectively. All dispersions were pseudoplastic fluids described accurately by Herschel-Bulkley model. The change of the biopolymer viscosity on pH showed the highest value at the pH 7.0 and it showed lower at acidic conditon that at alkaline condition comparatively.

• Journal of Microbiology and Biotechnology
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• v.3 no.3
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• pp.209-213
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• 1993

The flow behavior of the mycelial broth of glucoamylase hyperproducer Asp. niger No. PFST-38 for the production of glucoamylase were studied. The mycelial broth followed Bingham-pseudoplastic flow model described by Herschel-Bulkley equation. The yield stress increased with the increase in mycelial concentration. The dependency of the consistency index and the flow behavior index on the mycelial concentration could be expressed by a linear relationship. The consistency index increased proportionally with the mycelial concentration while the flow behavior index decreased with the increase in mycelial concentration. The flow property of the broth was related to the morphological data obtain in the previous study. The changes in apparent viscosity of the broth could be expressed as a function of the hyphal thickness as shown below.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.740-743
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• 2004

Rheological properties of gamma-irradiated arrowroot starch was examined to utilize as fundamental research data far processing. Irradiated arrowroot starch solutions (3, 4, 5, 6%) were gelatinized at $95^{\circ}C$ for 40 min, and its flow properties measured using rheometer at $30^{\circ}C$ and 10 to 200 rpm rotation rate. Rheological parameters of irradiated arrowroot starch gelatinized solution were calculated using Herschel-Bulkley equation. Gelatinized arrowroot starch solutions irradiated at $0^{\circ}C$ and 5kGy showed pseudoplastic fluid behavior, while those irradiated at 10, 20, and 30kGy were the dilatant with ${\tau}_y=0$ (yield stress).

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.13 no.1
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• pp.55-68
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• 2002

Flow properties of doenjang samples at various total solid contents (30, 32, 34, 36, 38, 40%) were evaluated in this study. Flow properties of doenjang samples was determined by using Haake concentric cylinderical viscometer and Instron testing machine with capillary extrusion viscometer, and consistency index(K), and flow behavior index(n) was also determined from power models, and yield stress was derived form Casson models and vanes methods. Doenjang samples showed shear-thinning (pseudoplastic) fluid with small magnitude of flow behavior index(n) (n=0.30-0.55). Casson yield stress was from 2.11 to 64.02(Pa). Vane yield stress was more effective than casson yield stress in property of reactivation. Apparent viscosity was decreased with the increase in temperature and activation energy was in the range of 6.58 to 10.70 kJ/mole. From the capillary extrusion method, K and n was increased with the increase in solid content with good correlation with. The result revealed that capillary extrusion method is useful for measuring the flow properties of doenjang.