• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.2058-2065
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• 2004

A light collecting probe named Multi-color Integrated Cassegrain Receiving Optics (MICRO) is applied to spark-ignited spherical spray flames to obtain the flame propagation speed in freely falling droplet suspension produced by an ultrasonic atomizer. Two MICRO probes are used to monitor time-series signals of OH chemiluminescence from two different locations in the flame. By detecting the arrival time difference of the propagating flame front, the flame propagation speed is calculated with a two-point delay-time method. In addition, time-series images of OH chemiluminescence are simultaneously obtained by a high-speed digital CCD camera to ensure the validity of the two-point delay-time method by the MICRO system. Furthermore, the relationship between the spray properties measured by phase Doppler anemometer (PDA) and the flame propagation speed are discussed with three different experimental conditions by changing the fuel injection rate. It was confirmed that the two-point delay-time method with two MICRO probes is useful and convenient to obtain the flame propagation speed and that the flame propagation speed depends on the spray properties.

• Design & Manufacturing
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• v.12 no.2
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• pp.57-62
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• 2018

In diabetics, daily blood glucose testing is generally required at home, and thus, performing blood collection several times a day using a blood line is essential. Blood collection in the home and in the hospital is a source of pain and is the second most common cause of infection. In blood collecting device generally consists of four major parts: inner-case, outer case, main shaft and triger, and the most import part among those for necessary functionality is the main shaft. Filling time and injection pressure, filling balance, strain-rate analysis of change based on availability of the product. The Moldflow of FEM simulation is used for the analysis of injection molding process. In this study, aims to create a technique for injection molding and manufacturing of a main shaft of a high-performance blood-collecting apparatus capable of automatically extracting a lancet to relieve pain through depth control of the lancet.

• Journal of the Korean Society of Safety
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• v.19 no.3 s.67
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• pp.20-25
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• 2004

In order to obtain the flame Propagation speed in freely falling droplet suspension Produced by an ultrasonic atomizer, a light collecting probe named Multi-color Integrated Cassegrain Receiving Optics (MICRO) is applied to spark-ignited spherical spray flames. Two MICRO probes are used to monitor time-series signals of OH chemilumine-scence from two different locations in the flame. The flame propagation speed is calculated by detecting the arrival time difference of the propagating flame front. In addition, time-series images of OH chemiluminescence are simultaneously obtained by a high-speed digital CCD camera to ensure the validity of the MICRO system. Furthermore, relationship between the spray properties measured by phase Doppler anemometer (PDA) and the flame propagation speed are discussed with k different experimental conditions by changing the fuel injection rate. It was confirmed that the MICRO probe system was very useful and convenient to obtain the flame propagation speed and that the flame propagation speed was different depending on the spray properties.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.122-127
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• 2011

In this study, it was compared collecting performance according to contact types between heatpipe and manifold of vacuum tube type solar collector. Between two types, direct contact type is better in collecting performance. On the other hand, Indirect type have advantage in maintenance. In the result of numerical analysis, As the temperature of heatpipe and flow rate of working fluid increased, difference of outlet mean temperature of two types became large. Also, it could be confirmed, as contact resistance between heatpipe and copper tube in indirect type increased, the difference increased too. Useful data in selection and design in vacuum tube type solar collector were proposed by the results of numerical analysis.

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.4
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• pp.123-128
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• 2009

In this paper, effective ways to produce distilled water with solar radiation was investigated. Four different boxes of condensation systems were compared. The bottoms of the boxes were identical, but the angles of the top collecting plates were different. During the solar radiation, condensation did not occur. Condensation started when solar radiation was decreased. The maximum condensation was found when the temperatures of the top and bottom parts were equal. The condensation was continued until sunrise with gradually reduced rate. When the collecting plate angle was $45^{\circ}$, condensation was the highest compared with other angles.

• Tribology and Lubricants
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• v.26 no.1
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• pp.21-30
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• 2010

In this research, it is investigated the collecting efficiency of jet oil to several types of piston oil cooling gallery by using recently developed PCJ (piston cooling jet) rig tester. So it will be selected for a better design of piston oil cooling gallery. The collecting efficiencies at each type of piston cooling galleries are measured under conditions of a few piston positions, and several oil jet pressures and oil viscosities. Furthermore, the type of jet cone will be compared for a few jet pressure conditions. The selected type of piston oil cooling gallery is planned to be applied to the target engine which is now developing to satisfy the EURO VI emission regulation.

• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.252-258
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• 2020

The aim of this study was to investigate the effects of timing of collecting date and concentration of IBA and NAA, in order to enhance initial activity and seedling quality of domestic strawberry. Strawberry cuttings were separately taken twice, in June 7 and in July 5, and IBA and NAA were treated with the concentrations of 0.025, 0.05 and 0.1% at cutting date, respectively. The seedlings were evaluated for the percentage of survival during 18 days at 6 times after tunnel cultivation. The NAA treatment was inappropriate for strawberry cutting due to the high rate of seedling mortality, regardless of the collecting date. The vitality of the seedlings was highest at IBA 0.1% in June collecting and at IBA 0.05% in July collecting. The seedlings from June collecting had a higher quantum yield at IBA 0.1% and the seedlings from July collecting at IBA 0.05%. Therefore, IBA could be more effectively applied than NAA to promote the vitality and quality with the appropriate concentration of 0.1% at June collecting and 0.05% at July collecting, respectively.

• Journal of Environmental Health Sciences
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• v.45 no.2
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• pp.126-133
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• 2019

Objectives: In this study, a nine-stage cascade impactor was used to collect dust, and the concentration of $PM_{2.1}$ & $PM_{10}$ and alveolar deposition ratio were investigated. Methods: This study was conducted at Kunsan National University from May to June 2016. A nine-stage Cascade Impactor was used to analyze the concentrations of fine and ultrafine dust and to estimate the alveolar deposition rate by particle size of atmospheric dust particles. The pore size of each stage of the collector used in this study gradually increased from F to 0, with the F-stage as the last stage. Results: The mass fraction of PM showed a bimodal distribution divided into $PM_{2.1}$ & $PM_{10}$ based on $2.1-3.1{\mu}m$. The average mass fraction of particulate matter in the range of $2.1-3.1{\mu}m$ was 44%, and the area occupied by $PM_{2.1}$ was similar. Therefore, the Gunsan area is considered to be a region where there are similar effects from anthropogenic and natural sources. Conclusion: Dust collecting efficiency increased with the stage of collecting fine dust, and the efficiency of collection was very low at the stage of collecting ultra-fine dust. The seasonal overall efficiency of the Cascade Impactor was 44% in spring and 37.4% in summer, and the average overall efficiency was 40.7%. The alveolar deposition rate of $PM_{2.1}/PM_{10}$ during the sampling period was estimated to be about 75% deposited in the alveoli.

• Plant Resources
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• v.7 no.3
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• pp.233-237
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• 2004

This study was conducted to develop effective production system in greenhouse for leaves and stems of Angelica acutiloba by using connect pots in 2003 and 2004. Seed germination rate and plant biomass of Angelica acutiloba collected in 2004 were higher than those harvested in 2003. Germination rate of Angelica acutiloba seeds collected in 2003 was 10％, while germination rate of seeds collected in 2004 was above 90％. Especially, plant growth and yield of Angelica acutiloba grown in connect pots sized with 4 ${\times}$ 4 ${\times}$ 5cm(length ${\times}$ width ${\times}$ height) were the highest. These results indicate that leaf and stem production of Angelica acutiloba can be improved by using connect pots and optimizing seed collecting time in greenhouse.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.43-58
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• 2020

Mulching plastic is used for the purpose of maintaining soil temperature, moisture, and weed and pest prevention in agriculture. Any remaining plastic after use may contaminate the soil and damage crop growth. To solve this problem, mulching plastic wrappers have been studied and developed, but the actual use rate is quite low due to their poor performance and frequent tearing of the plastic on the field. In this study, we developed a tractor attachable mulching plastic wrapper to minimize the tearing of the mulched plastic. The developed mulching plastic wrapper consists of hydraulic motors and pumps, valves, a microcontroller, and sensors. The collecting speed of the plastic mulch was calculated considering the tractor's travel speed and the radius of the collecting drum. A proportional controller was designed to control the rotating speed of the hydraulic motor as the plastic was wound around the collection drum and the radius increased. The performance of an indoor experiment was quite promising because the difference between the collecting speed predicted by the calculation and the actual collecting speed was 2.71 rpm. Based on a field verification test, the speed difference was max. 14.28 rpm; thus, the, proportional integral derivative (PID) controller needs to be considered to control the drum speed precisely. Another issue was found when the soil covered at the edge of the plastic was hardened or the road surface was uneven, the speed control was unstable, and the plastic was torn. In future research, vibrational plows will be equipped to break-up the harden soil for collecting the plastic smoothly.