• Composites Research
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• v.27 no.4
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• pp.168-173
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• 2014

The optimum condition of glass fiber/epoxy composites was investigated according to mixing ratio of two epoxy matrices. Novolac type epoxy and isocyanate modified epoxy were used as composites matrix. Based on chemical composition of mixing matrix, optimum mixing ratio of epoxy resins was obtained through various experiments. In order to investigate thermal stability and interface of epoxy resin, glass transition temperature was observed by DSC instrument, and static contact angle was measured by reflecting microscope. Change of IR peak and $T_g$ was conformed according to different epoxy mixing ratio. After fabrication of glass fiber/epoxy composites, tensile, compression, and flexural properties were tested by UTM by room and high temperature. The composites exhibited best mechanical properties when epoxy mixing ratio was 1:1.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1468-1472
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• 2007

The present study was carried out to determine the optimum conditions of different factors (ratio of lard to water, ${\beta}$-CD concentrations, mixing temperature, mixing time and mixing speed) on cholesterol reduction from lard by using crosslinked ${\beta}$-CD. Crosslinked ${\beta}$-CD was prepared with adipic acid. When the lard was treated under different conditions, the range of cholesterol removal was 91.2 to 93.0% with 5% crosslinked ${\beta}$-CD, which was not significantly different among treatments. In a recycling study, cholesterol removal with crosslinked ${\beta}$-CD in the first trial was 92.1%, which was similar to that with new crosslinked ${\beta}$-CD. In up to eight time trials, over 90% of cholesterol removal was found. The present study indicated that the optimum conditions for cholesterol removal using crosslinked ${\beta}$-CD were a 1:3 ratio of lard to water, 5% crosslinked ${\beta}$-CD concentration, $40^{\circ}C$ mixing temperature, 1 h mixing time and 150 rpm mixing speed. In addition, crosslinked ${\beta}$-CD made by adipic acid resulted in an effective recycling efficiency.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.1
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• pp.133-140
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• 2002

This article presents an application of a large-scale structural mixing model(Broadwell et at. 1984) to the blowout of turbulent reacting cross flow jets. Experimental observations, therefore, aim to identify the existence of large-scale vortical structure exerting an important effect upon the flame stabilization. In the analysis of common stability curve, it is seen that the phenomenon of blowout are only related to the mixing time scale of the two flows. The most notable observation is that the blowout distance is traced at a fixed positions according to the velocity ratio at all times. Measurements of the lower blowout limits in the liftable flame are qualitatively in agreement with the blowout parameter $\xi$, proposed by Broadwell et al. Good agrement between the results calculated by a modified blowout parameter $\xi$'and the present experimental results confirms the important effect of large-scale structure in the stabilization feature of blowout.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.12
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• pp.3377-3385
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• 1994

This paper introduces empirical correlations to obtain the gas/liquid flow rates and the spray drop size of low viscosity liquid injected by Y-jet twin-fluid atomizers. The gas flow rate is well correlated with the gas injection pressure and the mixing point pressure, based on the compressible flow theory. Similarly, the liquid flow rate is determined by the liquid injection pressure and the mixing point pressure, and a simple correlation for the liquid discharge coefficient at the liquid port was deduced from the experimental results. The mixing point pressure, which is one of the essential parameters, was expressed in terms of the gas/liquid flow rate ratio and the mixing port length. Disintegration and atomization mechanisms both within the mixing port and outside the atomizer were carefully re-examined, and a "basic" correlation form representing the mean diameter of drops was proposed. The "basic" correlation was expressed in terms of the mean gas density within the mixing port, gas/liquid mass flow rate ratio and the Weber number. Though the correlation is somewhat complicated, it represents the experimental data within an accuracy of ${\pm}15%$.EX>${\pm}15%$.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.3021-3031
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• 1994

Experiments have been performed to find out the effect of the mixing port length of Y-jet atomizers on the spray performance, using air and water as the test fluids. Water and air flow rates and drop sizes were measured at each injection pressure condition for different mixing port length. The air flow rate was almost unaffected by the change of the mixing port length. However, the water flow rate was relatively susceptible to the change of the mixing port length. The mixing point pressure was very much influenced by the mixing port length. Variations of spatial distribution of Sauter Mean Diameter (SMD, $D_{32}$) and the cross-section-averaged SMD ($D_{32,m}$) with different mixing port length and air/water mass flow rate ratio were examined. Generally, when the mixing port length was reduced, the mean drop size decreased and became spatially even.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.8
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• pp.645-651
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• 2015

The objective of this study is to experimentally investigate the effect of design parameter on the mass ratio of a central-driven ejector. The design parameters are the primary nozzle area and distance ratios, diffuser exit-area ratio and mixing-tube length ratio. The experimental setup was an open-loop continuous circulation system which has a movable nozzle ejector, an electric motor-pump, a water tank, a control panel and high-speed camera unit. We calculated the mass ratio using the measured primary and suction-flow rates with the experimental parameter of primary water-flow rate or pressure. The results showed that the mass ratio increased with the primary nozzle distance ratio and mixing tube length ratio, while the mass ratio decreased with the primary nozzle-area ratio and diffuser exit-area ratio.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.767-772
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• 2003

The clay which transported into a pond under the high water content condition have no effective stress which develop from the starting point of sedimentation and self-weight consolidation. Since sedimentation and self-weight consolidation dependent on self-weight of solids is made progress over a long time, to accelerating it have many advantages in the economic view In this paper, sand spreading method which is one of sedimentation and self-weight consolidation acceleration method is studied through a series of experiments considering the mixing ratio of sand and clay. The test results show that the mixing ratio of clay and sand of 1:0.2 is the biggest rate of consolidation and the pouring at the end point of sedimentation considerably effects on consolidation rate.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.4
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• pp.11-20
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• 2014

The objective of this study was to investigate the beating properties of two types of cotton pulps such as "cotton lint mixed pulp" and "cotton linter pulp". In order to improve refining characteristics, the effects of carboxymethyl-cellulose (CMC) pre-treatment, mixing ratio changes of cotton lint mixed pulp and cotton linter pulp, and refining load changes were analyzed. In mill application, it was possible to improve the refining characteristics and maintained the strength properties of the paper by applying increasing ratio of cotton linter pulp mixing and controlling the refining methods.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1436-1441
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• 2004

Achieving the maximum blasting efficiency with minimum abrasive consumption is a critical concern in surface preparation stage of shipbuilding and offshore industry. Increasing the abrasive flow rate beyond the optimum point results in a major reduction in productivity even though the amount of abrasive used is larger. So, this study is intend to find out the optimum abrasive-to-air mixing ratio which can make a significant improvement in blasting efficiency and remarkably reduce the amount of abrasive used. From the test results, it can be identified that as the abrasive feeding rate is increased linearly, blasting efficiency is increased to a maximum point and then gradually decreased in the form of a bell-shaped.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.431-437
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• 1998

This study was performed to ascertain the three-dimensional effect of the crack reduction and the restrained effect of crack growth, and to yield a suitable mixing ratio of the synthetic fiber reinforced soil. The results of the study are as follows ; 1) The synthetic fiber has the resisting force for crack because of the adhesion due to the attraction of soil particles. 2) As the synthetic fiber length and the mixing ratio are increased, mono filament synthetic fiber reinforced soil is increased the effects of crack reduction and the restraint of crack growth. 3) The fibrillated synthetic fiber is more effective than mono filament synthetic fiber for crack. 4) A suitable mixing ratio of synthetic fiber reinforced soil is 0.5% of the fibrillated synthetic fiber.