• 한국전기전자재료학회논문지
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• 제22권5호
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• pp.405-410
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• 2009

The conventional ultrasonic nozzle produces a mist by applying an ultrasonic vibration into a non-flowering liquid. In this paper, we first present a novel designed nozzle type sprayer that is able to apply an ultrasonic vibration directly to the moving liquid and generate a mist instantly. For the novel nozzle, a ring-type actuator of the novel nozzle was designed and built using the PZW-PMN-PZT ceramics. This paper will describe a variety of physical, mechanical, and electrical characteristics of the ultrasonic nozzle. The characteristics of the mist particles was also measured as the amount of the outflow liquid was varied.

• 한국환경복원기술학회지
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• 제16권6호
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• pp.135-143
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• 2013

Ultrasonic mist fogger and the fan were used for investigating the availability of fog circulation system in greenwall and the potential growing ability of the plant. The mist caused by ultrasonic mist fogger was circulated by the fan through the pipeline and supplied to the pots containing plants. Moisture content of the 3 different soils was measured at different irrigation time points. The moisture content of 15-26% in PP and Co soil was maintained at irrigation of 24H, 18H, 12H in a day. Proper growth condition was found in Ardisia pusilla and Hosta plantaginea at the height of L level after 1 month of growth when the plants were irrigated by the fog circulation system. The results suggest that the fog circulation, by ultrasonic mist fogger to the green walls is system of choice for suppling moisture to plants.

• 한국대기환경학회지
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• 제25권3호
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• pp.211-218
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• 2009

Feasibility study of using $Ti0_2$ mist generated by ultrasonic atomization for photocatalytic degradation of gaseous toluene was attempted in this study. For this, the photocatalytic reactor consisting of mist generator and photo-reactor was designed. Most of experimental results showed that steady state reached about 30 minutes after the start of experiments. The effects of $Ti0_2$ concentration, toluene concentration, and UV wavelength on toluene removal ratio were investigated. It was found that the highest removal efficiency was obtained when $Ti0_2$ concentration was 0.6 g/L in slurry. At this condition, it was found that the toluene removal efficiency increased as toluene concentration in feed decreased. In order to investigate the effect of UV wavelength, experiments were carried out using three UV lamps with different UV wavelength. The results showed that the highest removal efficiency was achieved when the lamp with the shortest wavelength were employed.

• 한국분무공학회지
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• 제11권4호
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• pp.251-265
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• 2006

To prevent the ozonosphere from being destroyed by Halon, it is an urgent task to find out Halon replacement. As one of the replacements water mist have showed broad applications by its advantages: little pollution to environment (not destroying the ozone layer or bring green house effect), extinguishing fire quickly, consuming a small quantity of water and having little damage to the protected objects. The methods of generating water mist strongly influence fire suppression effectiveness, which determine the cone angle, drop size distribution, flux uniformity, and momentum of the generating spray. The traditional water mist nozzle included pressure jet nozzles, impingement nozzles and twin-fluid nozzles. All of them have more or less disadvantages for fire suppression. Therefore, many research institutes and corporations are taking up with innovations in mist generation. This article provided some recent studies in State Key Laboratory of Fire Science (SKLFS) of University of Science and Technology of China. SKLFS have investigated new methods of generating water mist (i.e. effervescent atomization and ultrasonic atomization). and self developed a series of nozzles and developed advanced DPIVS (Digital Particle Image Velocimetry and Sizing) technique. Characteristics of water mist (the distribution of droplet sizes, flux density, spray dynamics and cone angle) produced by these nozzles were measured under different conditions (work pressure, nozzle geometry, etc.) using LDV/APV and DPTVS systems. A series of experiments were performed to study the fire suppression effectiveness in different fire scenario (different kindsof the fuel, fire size and ventilation conditions). The fire extinguishing mechanisms of water mist was also discussed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.55-56
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• 2006

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2000년도 추계총회,초청강연,특별강연,연구발표회
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• pp.181.1-181
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• 2000

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.101-104
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• 2022

Mist-CVD is known to have advantages of low cost and high productivity compared to ALD and PECVD methods. It is capable of reacting to the substrate by misting an aqueous solution using ultrasonic waves under vacuum-free conditions of atmospheric pressure. In particular, Ga₂O₃ is regarded as advanced power semiconductor material because of its high quality of transmittance, and excellent electrical conductivity through N-type doping. In this study, Computational Fluid Dynamics were used to predict the uniformity of the thin film on a large-area substrate. And also the deposition pattern and uniformity were analyzed using the flow velocity and particle tracking method. The uniformity was confirmed by quantifying the deposition cross section with an FIB-SEM, and the consistency of the uniformity prediction was secured through the analysis of the CFD distribution. With the analysis and experimental results, the match rate of deposition area was 80.14% and the match rate of deposition thickness was 55.32%. As the experimental and analysis results were consistent, it was confirmed that it is possible to predict the deposition thickness uniformity of Mist-CVD.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.215-216
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• 2006

• 한국결정성장학회지
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• 제1권1호
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• pp.107-116
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• 1991

초음파 진동자를 사용 분무 열분해시켜 $Pb(NO_3)_2$와 $TiO(NO_3)_2$ 용액으로부터 $PbTiO_3$ 미분말을 합성하고 미립자의 특성을 조사하였다. 또한 미립자 형성과정을 같은 방법으로 합성되어 문헌에 보고된 $BaTiO_3$, $ZrO_2$, ZnO 등의 미립자 형성과정과 비교 검토하였다.

• 반도체디스플레이기술학회지
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• 제21권4호
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• pp.81-85
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• 2022

Mist-CVD is known to have advantages of low cost and high productivity method since the precursor solution is misting with an ultrasonic generator and reacted on the substrate under vacuum-free conditions of atmospheric pressure. However, since the deposition distribution is not uniform, various efforts have been made to derive optimal conditions by changing the angle of the substrate and the position of the outlet to improve the result of the preceding study. Therefore, in this study, a deposition distribution uniformity model was derived through the shape and position of the substrate support and the conditions of inlet flow rate using the particle tracking method of computational fluid dynamics (CFD). The results of analysis were compared with the previous studies through experiment. It was confirmed that the rate of deposition area was improved from 38.7% to 100%, and the rate of deposition uniformity was 79.07% which was higher than the predicted result of simulation. Particle tracking method can reduce trial and error in experiments and can be considered as a reliable prediction method.