• Proceedings of the KSME Conference
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• 2002.08a
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• pp.299-302
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• 2002

Characteristics of the twin fluid spray with ultrasonic forcing are examined in order to obtain the high efficiency of cold fog spray of the automatic pest control machine which has been widely used for the equipment cultivation recently. An electrostrictive vibrator of PZT BLT and a magnetostrictive vibrator of ${\pi}type$ with 28 kHz are applied as the ultrasonic transducer. All experiments are made and observed in 4 methods of spray ; a conventional spray method without ultrasonic forcing, an indirect vibration method with ultrasonic forcing, an improving duality method by ultrasonic forced within liquid, and a combined use method with both of the indirect vibration method and the improving quality method. In results, It was clarified that the ultrasonic effects the atomization of spray droplets and its efficiency is about $10{\%}$ and especially much more in the case of the combined use method.

• Design & Manufacturing
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• v.9 no.2
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• pp.25-29
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• 2015

This paper presented characterization of spray velocity and angle of spray nozzle systems for cosmetic products. Diameter and length of nozzle orifice were chosen as shape factors of the spray system. Spray orifice of the spray pattern is a factor influencing the quality of the product. Fluid analysis was conducted by using "Fluent" to obtain spray angle and velocity. RSM (Response Surface Method) was used to approximate the relationship between these 2 factors and spray characteristics. To evaluate the proposed method, experimental work with existing was conducted and good agreement between simulation and experimental results.

• Food Science and Preservation
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• v.23 no.3
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• pp.355-360
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• 2016

In this study, the quality characteristics of spray dried powders from unripe fig extract were investigated. The protease activities of unripe fig and peeled unripe fig extract were 0.11 unit/mL and 0.28 unit/mL, respectively. The spray dried powder of unripe fig extracts was analzed using different maltodextrin ratios (F-MD 5, 5% maltodextrin; F-MD 10, 10% maltodextrin; and F-MD 20, 20% maltodextrin). The spray-dried powder showed the highest protease activity with F-MD 10 (0.84 unit/g). The moisture content and L value of the spray-dried powder were higher than those of the freeze-dried powder. The particle diameter of the freeze-dried powder ($209.67{\mu}m$) was higher than that of the spray-dried powders ($22.18{\sim}37.33{\mu}m$). The water absorption index ranged from 0.18 to 0.40, while the water solubility index ranged from 94.40% to 98.80%. In the in vitro digestion study, spray-dried powders of the unripe fig showed a protease survival range of 16.47%~24.80%. In conclusion, it is considered appropriate to use the spray-dried powder (F-MD 10) of unripe fig as a meat tenderizer for processing food.

• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.50-56
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• 1996

This experiment was carried out to investigate the effects of new material, bioceramic powder in the nutrient solution(0.02%) and foliar spray(0.2%) on the growth and fruit quality of aeroponically grown tomato(Lycopersicon esculentum MILL. cv. Seokwang). Plant height was lowered, but root growth was increased both treatment of bioceramic powder into the nutrient solution and foliar spray. Cluster growth of tomato plants increased up to 14% over than that of control in the plot of foliar spray with bioceramic powder. Total plant dry weight also increased when bioceramic powder was treated both into the nutrient solution and foliar spray. T/R ratio was reduced by the treatment of bioceramic powder, but NAR and RGR showed the highest in the plot of foliar spray treated with 0.2% bioceramic powder than that of the other plots. Cumulative fruit fresh and dry weight were reduced when bioceramic powder was treated into nutrient solution but foliar spray produced more cumulative fruit fresh and dry weight than that of control. It was shown that treatment of bioceramic powder into the nutrient solution and foliar spray could be improved sugar degree without reducing fruit yields.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.81-86
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• 1997

Spray dried powdered juice was processed from concentrated extract of jujube(Zizyphus jujuba MILLER). Spray drying of the extract solution could not be operated to have powder product by itself over whole concentration range and required addition of some carrier or support material. The concentrated extract of 26$^{\circ}$Bx was combined with carrier material solution to have a final concentration of 30$^{\circ}$Bx, and then spray dried. Proper addition level of carrier solid for physical and flavor quality of the powder product was determined to be 1 : 1 ratio to jujube solid. Combined use of maltose and gum arabic produced the best quality product among the studied carrier materials, which were maltose, dextrin, condensed milk and gum arabic. Enzymatic treatment in extraction process could increase the yield by 13~39%, but hurt the sensory quality of powdered juice. Treatment by 0.5% pectinase(0.05 unit/ml) may be used with lesser quality change for improved yield.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.24-29
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• 2003

Deep sea water has cold temperature, abundant nutrients and minerals, and good water quality that is pathogen-free and stable. Compared with surface water, deep sea water contains more nutrition salt, such as nitrogen and phosphor. Moreover, if has the good balance of minerals. Because of the ability of the spray drying process to produce a free-flowing power considering of spherical particles with a well-defined size distribution and the rapid drying times for heat-sensitive material, spray drying is attractive for a wide range of applications spray drying is a unique unit operation in which powders are produced from a liquid feed in a single processing step. Key component of the process are atomizer, spray chamber. Design of spray chamber should be based on the atomizer type, the production rate, and the particle size required. Because of the complex processes taking place during spray drying, traditional design method are based on pilot-plant tests and empirical scale-up rules. Modern technique such as CFD have a role to play in design and troubleshooting.

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.2053-2065
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• 2003

The current trend in automotive finishing industry is to use more electrostatic rotating bell (ESRB) need space to their higher transfer efficiency. The flow physics related with the transfer efficiency is strongly influenced by operating parameters. In order to improve their high transfer efficiency without compromising the coating quality, a better understanding is necessary to the ESRB application of metallic basecoat painting for the automobile exterior. This paper presents the results from experimental investigation of the ESRB spray to apply water-borne painting. The visualization, the droplet size, and velocity measurements of the spray flow were conducted under the operating conditions such as liquid flow rate, shaping airflow rate, bell rotational speed, and electrostatic voltage setting. The optical techniques used in here were a microscopic and light sheet visualization by a copper vapor laser, and a phase Doppler particle analyzer (PDPA) system. Water was used as paint surrogate for simplicity. The results show that the bell rotating speed is the most important influencing parameter for atomization processes. Liquid flow rate and shaping airflow rate significantly influence the spray structure. Based on the microscopic visualization, the atomization process occurs in ligament breakup mode, which is one of three atomization modes in rotating atomizer. In the spray transport zone, droplets tend to distribute according to size with the larger drops on the outer periphery of spray. In addition, the results of present study provide detailed information on the paint spray structure and transfer processes.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3062-3067
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• 2007

HVOF thermal spray guns are now being widely used to produce protective coatings, on the surfaces of engineering components. HVOF technology employs a combustion process to heat the gas flow and melt the coating materials which are particles of metals, alloys or cermets. Particle flow which is accelerated to high velocities and combustion gas stream are deposited on a substrate. In order to obtain good quality coatings, the analysis of torch design must be performed. The reason is that the design parameters of torch influence gas dynamic behaviors. In this study, numerical analysis is performed to predict the gas dynamic behaviors in a HVOF thermal spray gun with various torch shapes. The CFD model is used to deduce the effect of changes in nozzle geometry on gas dynamics. Using a commercial code, FLUENT which uses Finite Volume Method and SIMPLE algorithm, governing equations have been solved for the pressure, velocity and temperature distributions in the HVOF thermal spray torch.

• Journal of ILASS-Korea
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• v.1 no.1
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• pp.55-62
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• 1996

In a fuel injection engine, atomization of liquid fuel and mixture formation process has influenced(or affected) directly on the engine performance and pollutant emission. In this study, the characteristics of fuel spray and the behaviors of secondary atomization developed at the downstream of the valves were investigated using an image processing method. Solid and perforated valves are chosen in order to evaluate the valve performance in terns of air flow rate, valve opening angle and valve shape. Experimental results clearly indicate that the spray atomization quality can be improved by increasing the perforated rat io and the blockage rat io in the perforated valve, the characteristics of spray atomization is improved by using the perforated valve with high perforated rat io and blockage ratio.

• Resources Recycling
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• v.11 no.5
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• pp.24-29
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• 2002

In this study, to improve the color of iron oxide from waste pickling acid at the cold rolling mill, the quality control technologies especially about color were investigated on the spray roaster and iron oxide powder. At the operation condition of the spray roaster, the charge amount of waste acid per hour, temperature, numbers of spray nozzle were investigated. At admixing process, titanium oxide, silica, goethite were tested. Color character of iron oxide can be improved by process control at spray roaster and by admixing process at a pigment factory Iron oxide from results of this study is enough to use as the colorant of concrete product.