• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.178-181
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• 1998

An exopolysaccharide, designated as A49-Pol, was produced from Bacillus polymyxa KCTC 8648P in nitrogen sufficient conditions. The viscosity of the culture broth increased up to $2\times10^4$cP in 38 hours of culture and then decreased to $1.5\times10^4$CP at 48 hours. The $1.0\%$ (w/v) solution of purified A49-Pol represented pseudoplasticity with a viscosity of $2.7\times10^4$cP which was two times higher than xanthan at the same concentration. The viscosity of the A49-Pol solution was also greatly affected by its concentration in comparison with the xanthan solution. The viscosity of $1.0\%$ A49-Pol solution was 930-fold higher than its $0.2\%$ solution, whereas the corresponding viscosities of xanthan solution experienced only l7-fold difference. The viscosity was observed to be maximum at pH 7.0 in both A49-Pol and xanthan solutions, and gradually decreased as the pHs of the polysaccharide solutions went to acidic or alkaline regions. The viscosity of A49-Pol solution was very sensitive to temperature compared to xanthan and decreased with increasing temperature. The viscosity of $0.6\%$ solution of A49-Pol was 8,100 cP at $10^{\circ}C$ and 55 cP at $50^{\circ}C$. The viscosity was also affected by the presence of surfactants such as Span 20 and Triton X-l00 ; with $0.5\%$ Triton X-l00 (v/v), the viscosity of A49-Pol solution increased by $50\%$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.3 s.174
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• pp.581-592
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• 2000

To obtain an excellent product and decide on optimum molding conditions, it is important to establish the relationship between molding conditions and viscosity. The composites is treated as a pseudoplastic fluid, and the expansional/contractional viscosity of the fiber-reinforced polymeric composites is measured using the parallel plastometer, and the model for flow state has been simulated with the viscosity. The effects of expansional slip parameter $\alpha_{e}$, and expansional/contractional viscosity ratio ${\mu}_{\gamma}$, on the mold filling parameters are also discussed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.161-162
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• 2022

The purpose of this study is to determine the viscosity of the polymer-cement composites(PCCs) for crack repair of RC structures and to investigate its compaction. According to the study on the viscosity and compaction property of PCCs for crack repair, the viscosity of PCCs varies greatly depending on the polymer type and polymer cement ratio, and by mixing silica fume into PCCs, appropriate viscosity and excellent flow can be controlled without separation of cement and water. As a result of this study, basic data on the viscosity, fluidity, and compaction properties of PCCs for crack repair of RC structure can be obtained.

• Proceedings of the Korean Society of Laser Processing Conference
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• 2001.05a
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• pp.31-34
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• 2001

Laser cladding Processing allows rapid transfer of heat to the material being minimum conduction into base metal. The effects of CO$_2$ laser cladding with high powder were investigated. High viscosity bronze powder consists of bronze powder used at a high temperature. The material has a high viscosity So that it can be substrate. Therefore. Laser cladding can be processed on a curved or slope surface. CO$_2$ laser cladding was designed It consists of the high viscosity bronze powder the shielding gas system and the preheating system The high viscosity powder properly at 0.3g/s and 0.50g/s. Because of the metallic bond between bronze per the hardness of dilution layer was suddenly increased. Experimental as results viscosity mixed powder can be a useful cladding material.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.11
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• pp.16-21
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• 1999

Recently, the rheology on the fluidity of materials has been progressed remarkably. Viscosity measurement for precision-accuracy has needed very important to measure the rheological properties of materials in the field of chemistry-fiber, paint, printing-ink, plastics, rubber, foodstuff-industry, etc. And many methods of measurement have been developed lately. So in this experimental study, small capacity torque transducer with type of strain gage, different method against other existing viscometers, measured viscosity about a liquid that has flowing characteristics of newtonian liquid. Using the assumed computational equation of viscosity, it has same value of viscosity in each different radius of rotating cylinder. In the result, this equipment will be used in the viscosity measurement of a liquid taking flowing characteristics of newtonian liquid.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.35-36
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• 2016

Recently, with the increasing demand of high performance of concrete, the mix design of concrete mixture has became low water-to-binder ratio with high binder content. To compensate these trend of mix design, high range water reducer, or superplascizier has been invented to achieve high flowable concrete. Although this superplasticizer provides favorable workability based on its dispersing action on the components of concrete mixture, it has an limitation of decreasing viscosity of the mixture, and thus it is difficult to secure sufficient workability for high performance concrete mixtures with high binder content. To improve the workability of concrete with high viscosity, recently, low-viscosity type superplasticizer was introduced, and in this research, a fundamental properties of low-viscosity type superplasticizer is evaluated.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.43-45
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• 2001

This study simplifies the phenomenological theory of viscosity previously proposed by the present authors. This simplified theory has only two thermodynamic properties and one parameter, as opposed to its predecessor, which has many, allowing for easy calculation of the liquid viscosities. The viscosity of liquid metals, an excellent test for checking the validity of the liquid theory, can be calculated using the equation based on the simplified theory. The calculated results by the current theory turn out to be good for the liquid metals, including sodium, potassium, rubbidium, cesium, lead and mercury.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.5
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• pp.509-512
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• 1991

Rheological property and apparent viscosity(η)of several semi-solid foods were measured with extrusion capillary viscometer. Apparent viscosities of several semi-solid foods ranged from 0.2714 Pa.s to 2.6453 Pa.s Rheological property of spread type semi-solid foods was pseudoplastic (with yield value). Especially, as the moisture content and temperature of Chungkook-jang spread increased, apparent viscosity decreased. On the contrary, as the added soybean oil content of Chungkook-jang spread increased, apparent viscosity also increased.

• Tribology and Lubricants
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• v.24 no.1
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• pp.1-6
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• 2008

An experimental study was conducted to evaluate the viscosity characteristics of multi-grade engine oils in which contain diesel fuels. Unused engine oils of SAE 5W40, 10W40 and 15W40 were blended with a diesel fuel ratio of 5%, 10%, and 15%. The viscosity of a diluted engine oil was measured with temperature variation ranging from $-20^{\circ}C$ to $120^{\circ}C$ using a rotary viscometer. The diluted engine oil in which is blended to a diesel fuel plays an important role for decreasing an engine oil viscosity, which may decrease the oil film thickness and a load-carrying capacity. Test results show that the viscosity tends to fall for the increased temperature when engine oil is mixed with a diesel fuel. Especially, the viscosity at a low temperature zone is radically decreased compared with a high temperature zone. Based on the experimental results, the empirical equation that can predict the viscosity of diluted engine oil is expressed in the exponential function with the variation of the temperature and a fuel ratio of diluted engine oil. This equation may be possible to predict the limitation of the oil-fuel dilution rate at the concept design stage of the CDPF system, which doesn't affect the influence of the tribological components.

• Journal of the Korean Wood Science and Technology
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• v.45 no.2
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• pp.223-231
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• 2017

This work was conducted to investigate on the effect of urea-formaldehyde (UF) resin viscosity on plywood adhesion. The viscosity of UF resin was controlled either by adjusting the condensation reaction during its synthesis to obtain different target viscosities (100, 200 and 300 mPa.s) at two levels of formaldehyde/urea (F/U) mole ratios (1.0 and 1.2) or by adding different amounts (10, 20 and 30%) of wheat flour into the resins for the manufacture of plywood. When the viscosity of UF resin increased by the condensation reaction, the adhesion strength of plywood bonded with UF resin of 1.2 F/U mole ratio consistently increased, while those bonded with the 1.0 F/U mole ratio resin slightly decreased, suggesting a difference in the adhesion in plywood. However, the adhesion strength of plywood decreased as the viscosity increased by adding wheat flour, regardless of F/U mole ratio. The manipulation of UF resin viscosity by adjusting the condensation reaction was much more efficient than by adding wheat flour in improving the adhesion performance of plywood. These results indicated that a way of controlling the viscosity of UF resin adhesives has a great influence to their adhesion in plywood.