• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.3
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• pp.130-137
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• 2011

Experimental investigations are conducted to figure out the feasibility of $Al_2O_3$ nanofluids as the alternative coolant for car engine. For the purpose, the thermal conductivities and viscosities of water/commercial coolant based $Al_2O_3$ nanofluids with 0.3, 1.0, 2.0 and 3.0 vol. % at temperatures ranging from $25^{\circ}C$ to $35^{\circ}C$ are measured. Thermal conductivities are measured using the transient hot-wire method and also viscosities are measured by Brookfield LVDV-III rheometer. Based on the results, it is shown that thermal conductivity of $Al_2O_3$ nanofluids with 3.0 vol. % is increased about 11% at $35^{\circ}C$ and the increment of viscosity approaches to 84% at shear rate of 600(1/s) and 80% at shear rate of 960(1/s) in the same temperature. with fundamental data for the thermal conductivity and viscosity of the nanofluids, the feasibility of $Al_2O_3$ nanofluids as the alternative coolant for car engine are discussed.

• YAKHAK HOEJI
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• v.36 no.6
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• pp.538-547
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• 1992

Optimal synthetic condition of barium sulfate were investigated from the viewpoint of yield and bulkiness according to a randomized complete block design proposed by G.E.P. Box and K.B. Wilson. Barium chloride and magnesium sulfate were utilized as reactants in order to prepare barium sulfate in this study. It was found that optimum temperature range of reactant solutions was $60{\sim}100^{\circ}C$ and the optimum concentration range of the reactant solutions was $10{\sim}17.3%$ and $10{\sim}20%$ respectively, on the viewpoint of yield and bulkiness. The optimum mole ratio of $BaCI_2$ to $BaSO_4$ was in the range of $1.50{\sim}2.0$ and the optimum mole ratio of $BaCI_2$ to $BaSO_4$ was in the range of $1.50{\sim}2.0$ and the optimum reacting time range was $15{\sim}20$ minutes. The optimum drying temperature range was $110{\sim}130^{\circ}C$ from the viewpoint of yield, but it was $90{\sim}110^{\circ}C$ on the basis of bulkiness. Apparent viscosity of barium sulfate suspensions dispersed in various concentrations of Na. CMC was measured by using Brookfield synchrolectric viscometer model LVT, the relative equation, log ${\eta}_{sp}=A+B.{\phi}$ was examined and the equation was found to agree fairly well. 1 w/v% Na. CMC aqueous solution and 0.1 volume fraction of $BaSO_4$ powder were optimum in the preparation of $BaSO_4$ suspension showing highest viscosity at infinite shearing.

• Proceedings of the SOHE Conference
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• 1997.12a
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• pp.45-49
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• 1997

To study the effect of amylose on the mechanism of gel formation, swelling power, water solubility, the pattern of alkali gelatinization and gel properties were investigated. The swelling power of waxy maize starch(Amioca) was the highest and followed by those of PFP ＞Amaizo ＞ Amylomaize Ⅶ. Amioca showed higher iodine affinity of soluble amylose than other maize starches. The apparent viscosity of alkali gelatinization measured by Brookfield viscometer for Amaizo was $70{\pm}10^3cp$ which was higher than Amylomaize VII. The apparent viscosity of PFP was increased to $70{\pm}10^3cp$ and then decreased. As maize starches were autoclaved at $121^{\circ}C$ with starch : water ratio (1:9) and autoclaving-cooling cycle were up to 4 times, gel properties were measured by rheometer. Amaizo showed the highest value for hardness, adhesiveness, springiness, cohesiveness, and hardness of gel after two times of autoclaving-cooling cycles was the highest. Gel properties was thus affected by the chain length of amylose rather than amylose content.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.547-552
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• 2004

Attempt was made to establish identification methods for irradiated starch. Commercial starches (corn starch/CS, sweet potato starch/SS, and potato starch/PS) were irradiated at 0-6.0 kGy and used to measure viscosity with Brookfield DV-III programmable rheometer. Starch suspensions were prepared at 8.0 (7.2%, d.b.), 8.5 (7.3%, d.b.), and 9.0% (7.3%, d.b.) for CS, SS, and PS, respectively at 100 rpm in spindle speed. Results showed viscosities of samples significantly decreased (p<0.05) as irradiation dose increased, with $R^2$ 0.9754, 0.9618, and 0.9888 for CS, SS, and PS, respectively. Irradiation dose at 1.5 kGy induced decrease in viscosity as compared to non-irradiated control by 34, 57, and 51% in CS, SS, and PS, respectively, suggesting viscometry could lie applied to identify irradiated starches. Solubility and alkali number of irradiated starches significantly increased with irradiation doses, while swelling power decreased (p<0.05). Results suggested solubility, alkali number, and swelling power for irradiated starches complement identification results of viscometry.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.4
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• pp.9-15
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• 2013

An oxidized starch ester was prepared and used for surface sizing. Esterification of starch decreased both Brookfield viscosity and Brabender viscosity substantially even though the solids level was increased by 2% from 14% to 16%. Surface sizing with the esterified starch gave better performance in tensile strength, stiffness and compressive strength than surface sizing with oxidized starch in the laboratory. Advantages in strength improvement, however, were not obtained when it was applied in commercial papermaking process. This was attributed to the fact that the influence of starch types has been nullified by high pressure penetration that occurs in the commercial papermaking process. Drying energy consumption, however, decreased by 3.3% by substituting the low solids oxidized starch with a high solids starch ester.

• Korean journal of food and cookery science
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• v.32 no.3
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• pp.253-260
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• 2016

Purpose: To develop fat-free dressing containing a resistant starch (RS) as a dietary fiber, the viscosity and stability of various type RSes prepared from wheat, maize, potato, rice, waxy rice, and amaranth starches were investigated by using Brookfield viscometer. The shape of RS granule in the dressing during storage was also observed. Methods: The viscosity of fat free dressing with different retrograded RS3 (RS3V) prepared from waxy rice starch with 0.1% lemon vinegar and ascorbate mixed solution had higher RS3 that was maintained constant during storage. Annealing and heating prior to cross-linking, and heating after cross-linking increased RS level of RS4 type starches. Results: The viscosities and stabilities of dressings with RS were different depending on starch sources and RS preparation conditions. The heated RS4 (HRS4) increased in viscosity and stability with RS4 addition. Especially the fat-free dressings with HRS4 prepared from rice and waxy rice starches maintained stability regardless of separation after one month storage with only 7% separation after 6 month storages. The shape of RS4 granule in acidic medium of dressing did not change until 6 months. Conclusion: In this study, RS4 made by the rice and waxy rice starches showed high viscosity and maintained stability of the fat-free dressings during storage.

• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.114-121
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• 2000

A study was carried out to establish a detection method for irradiated black and white pepper. Samples were packed in polyethylene bags and irradiated with 2.5, 5, 7.5, 10 and 15 kGy using a Co-60 irradiator. The samples were suspended in water, and alkalized with sodium hydroxide solution. Apparent viscosity was determined after heat gelatinization using a Brookfield DV-III rotation viscometer at 30。C with 30, 60, 90, 120, 150, 180, and 210 rpm. Means and standard deviations of the viscosities of all samples decreased by increasing the stirring speeds. The viscosities increased in all samples by increasing the concentration. Regression expressions and coefficients of viscosity which decreased with increasing irradiation dose of 10% and 13% black pepper, and 7% and 10% white pepper were 0.9531 (y=-131.29x+1,769.0), 0.9725 (y=-351.33x+4,036.0), 0.9731 (y=2,208.0e${^-0.3546X}$), and 0.9959 (y=5,116.0e${^-0.2887X}$), respectively, at 120 rpm. This trend was similar fur all stirring speeds. These results suggest that the detection of irradiated black and white pepper at various doses is possible by the viscometric method.

• Journal of the Korean Wood Science and Technology
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• v.22 no.1
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• pp.85-90
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• 1994

The flow properties of binder latices for paper coating were investigated, together with dynamic viscoelastic properties of latex films and electron micrographs of latices, under various conditions. The amphoteric latex, binder pigment latex and anionic latex were used in this work. The amphoteric latex has both anionic and cationic functional group on its surface. The binder-pigment with a core-shell structure has dual functions : plastic pigment and binder. The low shear viscosity of binder latices and clay slurry were measured with Brookfield vis cometer. At low-shear rates. the viscosity decreased with increasing particle size of latex. On the amphoteric latex surface, the carboxyl groups are assumed to be fully dissociated over the region of pH 9~12, but the density of negative groups seems to be increased because of the gradual decrease in the degree of dissociation of amino groups. Since the apparent particle size of latex increases with surface charge, the electroviscous effect can be observed. On the anionic latex surface, the charge density is assumed to be nearly constant above pH 8. However, below pH 8 the coagulation of particles could be observed probably because of the decrease in the charge density.

• Journal of Life Science
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• v.8 no.5
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• pp.526-531
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• 1998

In this study, the composition and characteristics of poly-$\beta$-hydroxybutyrate (PHB) biosynthesized by Actinobacillus sp. EL-9 are investigated. PHB produced by Actinobacillus sp. EL-9 was identified as the homopolymer of 3-hydroxy-butyric acid (PHB) by infrared spectroscopy and nuclear magnetic resonance spectroscopy analysis. The melting tem-perature (T$_{m}$), and crystallization temperature(T$_{c}$) of PHB was 169.7$^{\circ}C$ and 69.13$^{\circ}C$, respectively. The viscosity on he basis of Brookfield viscometer was 6.01 ㎗/g. The viscosity-average molecular weight estimated by Mark-Ho-wink-Sakurada equation was 1.08$\times$10$^{6}$ ($\pm$3,000).00).

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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• pp.50-55
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• 2014

An oxidized starch was modified for surface sizing via etherification and esterification. Propylene oxide (PO), sodium monochloroacetate (SMCA), and acrylonitrile (AN) were used as etherification, and vinyl acetate monomer (VAM), maleic anhydride (MA), fumaric acid (FA), and itaconic acid (ITA) were used for esterification. Esterification and etherification of starch decreased both Brookfield viscosity and Brabender viscosity substantially even though the solids level was increased by 2% from 14 to 16%. Surface sizing performance of starches in tensile strength, stiffness and compressive strength was improved by esterification and etherification of the oxidized starch. Especially, SMCA etherification was found to be the most effective modification method.