• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.914-916
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• 2009

Using gelatin and acacia as wall and electronic ink as core substance, microcapsules were prepared by complex coacervation to fabricate a flexible electronic paper display. In order to obtain the microcapsules in a narrow dispersed distribution, we focus on the interfacial tension between the hydrophobic electrophoretic ink and an aqueous polyelectrolyte solution, through controlling sodium dodecyl sulphate (SDS) concentration and stirring rate. The existence of anionic surfactant of SDS not only decreases the droplet diameters, but also reduces the diameter size distribution. And, as the stirring rate is increased, the average size of microcapsule is also decreased.

• Corrosion Science and Technology
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• v.9 no.2
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• pp.87-91
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• 2010

It is pointed out that non-wetting behavior of liquid Zn alloy occurs on high-tensile strength steels, which usually contain Si and Mn. There have been a lot of investigations to improve the above wettability of liquid Zn alloy with steels containing Si and Mn. Although those studies evaluated the wettability qualitatively by observation of the surface of steels galvanized by Zn or exfoliation test of Zn with substrate steels and so on, it is required to evaluate the wettability of liquid Zn with steels by measuring contact angle, work of adhesion, spreading velocity etc. which are usually used to assessment of general wetting behavior. In the present work, we evaluated the wettability of liquid Zn with steels containing Si and Mn by applying a sessile drop method to measure the change in contact angle and diameter of liquid Zn droplet wetted on steels.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.4
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• pp.904-911
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• 2001

The fuels of water-in-oil emulsion have a potential of reducing PM(Particulate Matter) and NOx emissions, and increasing combustion efficiency in the furnaces and the burners. For making the most of the beneficial of the secondary atomization due to the microexplosion, the water droplets distributed in the oil must have the optimal sizes. The purpose of this paper is to investigate the water droplet size distribution characteristics of the different types of the static mixers. For analysis the size distribution characteristics efficiently, image analysis system wes constructed and an appropriate image processing algorithm was developed. Two kinds of static mixers: Kenics type and RF type, were tested. As a results, RF type static mixer shows a better characteristics in the mean drop size, particularly in the condition of high water content.

• Journal of ILASS-Korea
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• v.17 no.1
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• pp.20-26
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• 2012

Inkjet printing is one of the direct writing technologies and is able to form a pattern onto substrate by dispensing droplets in desired position. Also, by inkjet technology manufacturing time and production costs can be reduced, and procedures can be more efficient. To form a metal pattern, it must be harmonized with conductive nano ink, printing process, sintering, and surface treatment. In this study, micro patterning of conductive line has been investigated using the piezoelectric printhead driven by a bipolar voltage signal is used to dispense $20-40{\mu}m$ diameter droplets and silver nano ink which consists of 50 nm silver particles. In addition, hydrophobic treatment of surface, overlap printing techniques, and sintering conditions with changing temperature and times to achieve higher conductivity.

• Journal of Ocean Engineering and Technology
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• v.14 no.2
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• pp.44-52
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• 2000

The dispersion of surface oil is generally described as a break-up of oil slick into small oil droplets. These small droplets are subjected to turbulence and vertical circulation so that it can be entrained into subsurface. Sometimes they tend to be submerged into sea bottom permanently. The diameter of oil droplets is a critical parameter to determine their behavioral characteristics under water surface. At the same time the variations of droplet stability depends on the weathering of it. That is why the weathered oil has different mechanism from the unweathered one. The variability of physical properties of oil including viscosity and density contribute to interfere with effective separation of oil and emulsion droplets in water. Also in the presence of interactions among the droplets there are coalescing or coagulating effects on the dispersion process of droplets.

• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.13-21
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• 2001

The effect of water spray for the fire sprinkler depends on droples distribution over maximum possible floor area. The present study are carried out for the characteristics of water spray and droplets experimentally and numerically km two fire sprinkler heads which are CHM head and CHl heal CHl head is self-production and CHl head is widely used up to date. As the result of using CHM head, water spray and droplets are distributed over large area because CHM head has smooth surface and non-flamed shape. When the pressure of fire sprinkler head is low, SMD(sauter mean diameter) is large and when the pressure of fire sprinkler head is high, SMD is small.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.2
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• pp.27-32
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• 2000

The main objective of this work is to investigate the effect of ambient conditions on the spray behavior and spray characteristics of high-pressure fuel injector. For this purpose, the effects of ambient pressure and temperature on the spray characteristics have been studied by applying the analysis of visualization system and phase Doppler particle analyzer. In this experiment, the visualization of spray behavior was performed under various ambient gas conditions and injection parameters such as gas temperature, ambient pressure, injection pressure of injector, and axial distance from the nozzle tip. Based on the investigation results, the spray tip penetration and spray width decrease with the increase of ambient gas pressure in the spray chamber. The effects of the spray parameters on the microscopic characteristics of gasoline spray were discussed.

• Fire Science and Engineering
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• v.9 no.2
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• pp.10-16
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• 1995

This study discribes characteristics of water spray for extinguishment of gasoline fire. Experiments are carried out for the gasoline pool fire nth the atomizing nozzles. Droplet size, spray pressure, amount of water which reaches the flame base and velocity of water spray are measured to find extinguishment conditions. Air entrainment due to the water spray and extinguishing process of gasoline fire by water spray are visualized. Boundary conditions of water spray for extinguishment of gasoline pool fire is quantitatively shown. As the result of experiments, it is found that the velocity of entrainment air and sprayed water are almost same and the water droplets size having small diameter under 40$\mu\textrm{m}$ can not extinguish the fire because too small droplets does not reach the fuel surface.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.288-291
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• 2004

The spray characteristics of coaxial swirl injector under ambient high pressure conditions were investigated in this paper. Three injectors were used to study the effect of recess length and fuel injector type(open or closed). In this research, experimental conditions(ambient gas density) were calculated by Buckingham Pi-theory and spray characteristics of the injectors were represented by mass flow rate according to the injection pressure, the spray angle, mass distribution, and mean diameter of droplet.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.119-127
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• 2021

Small drops in gas cause some problems for downstream equipments such as turbine, compressor and etc. In some cases, we are obliged to remove hazardous liquid mist from gas. In order to remove water or other liquids from the gas, there are some equipments like mesh mist eliminator and vane-plate mist eliminator. oil mist filter is a kind of liquid eliminator equipments used to remove the liquid with 1-10um droplet diameter from the gas. In this paper is determine the factors affecting the oil mist filter efficiency using CFD. length and angle of the filter were considered and the results and compare the results of the efficiency tests, showed error of less than 3%. optimum filter can remove more than 87.3% between 1 and 10um of oil mist.