• Journal of Biosystems Engineering
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• 제21권4호
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• pp.456-466
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• 1996

Electrostatic spraying is needed for today's sustainable farming. An electrostatic spraying nozzle was developed and its spraying performance was evaluated. High voltages of 15㎸, 20㎸, and 25㎸ were supplied for the electrostatic electrode. Artificial and real apple targets were used for the spraying experiments. Insulated material was used around the electrode to protect the loss of electrostatic effect. Three angles (0, 45, 90 degree) of spraying direction were used for the spraying test. The performance of electrostatic spraying was improved from 204.5% upto 429.2% on the apple targets.

• Journal of Biosystems Engineering
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• 제24권5호
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• pp.391-398
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• 1999

The spraying status of the electrostatic sprayer was evaluated by processing surface spraying images of the natural leaves. Water solution of the fluorescent material was used as a spray medium. The image of the lights reflected by fluorescent droplets was captured under UV light using a color CCD camera. Coverage rate, particle density, and the size distribution of particles were analyzed from the surface images of leaves under various spraying conditions such as spraying nozzle angle and object distance. Spraying characteristics of the electrostatic sprayer was evaluated in comparison with the conventional one. In a case of electrostatic sprayer, coverage rate and particle density increased by the average of 1.57times and 1.01times respectively under various nozzle angles and distances. The number of particle under the diameter of 50 ${\mu}{\textrm}{m}$ also increased significantly.

• Journal of Biosystems Engineering
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• 제29권1호
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• pp.21-28
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• 2004

Spraying is one of the most efficient methods for pesticide and insecticide control. Generally, orchard sprayers(aircarrier sprayer) are used for such applications. However, when an orchard sprayer is used, only 20% of total amount of spray deposits on the target. The rest of spray are not only wasted but are also potential sources of environmental pollution. The research far the development of electrostatic spraying system for orchard sprayer was conducted to develop the new pesticide application technology for the reduction of environmental pollution and f3r the production of safe agricultural products. The spray characteristics for nozzles with the different charging methods were tested and the effect of electrostatic charge was analyzed, in the laboratory experiments. The results of this study indicate that the capacitive type of electrostatic spraying nozzle exhibits a large current deposition of water sprays on the sample target. The covering area ratio by conventional spraying system was 10.2%, while that of electrostatic sprays with pulse induction charging method gave the increased covering area ratio by 4.3 times.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.893-898
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• 2003

An experiment was conducted to characterize water droplet charging performance of an electrostatic spraying nozzle for an electrostatic wet scrubber. Charge-to-mass ratios, the nozzle currents divided by the mass flow rate of water were obtained with respect to the applied voltage to the ring-electrode for 2 different flow conditions. It was shown that the charge-to-mass ratio increased in proportion to the applied voltage and tended to saturate at a certain higher voltage.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권12호
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• pp.573-578
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• 2003

In this study, new type of induction charging system for electrostatic spraying was manufactured and proposed to improve the electrical safety and charging efficiency. And parameters of proposed system to generate the maximum deposition current with electrical safety were selected and investigated. The selected parameters were frequency of square pulse and thickness of insulation material, outer diameter of device and thickness and positions of electrode. Charging quantity of water drop was measured by deposition current detected from sensing plate indirectly. The maximum deposition current for each parameter were 3.5[uA] at the frequency of 15[kHz] and thickness of 0.25[mm] insulating layer. And maximum deposition currents were 2.8[uA] and 3.0[uA] at 25[mm] outer diameter of charging device and 0.25[mm] thickness of electrode each. Effects of electrode position from spraying nozzle on deposition current was a little.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1169-1174
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• 2013

The objective of this work was to increase the efficiency of ultraviolet-light emitting diodes at 375 nm for sterilization. Since $TiO_2$ had antibacterial properties, which were attributed to the appearance of hydroxyl radicals and superoxide radical anions on the surface species under ultra violet radiation at about 387 nm, photo-reactive layers such as Ag-doped $TiO_2$ were coated on aluminum substrates by electrostatic spraying. Crystallinity and surface morphology of the coating layer were examined by X-ray diffraction ${\theta}-2{\theta}$ scan and field emission-scanning electron microscope, respectively. In an antibacterial test, we observed above 99% reduction of Escherichia coli populations on 3 or 5 mol% Ag-doped $TiO_2$ layers after irradiation for 2 hrs at 375 nm, while very low inactivation on bare aluminum substrates occurred after irradiation as the same condition.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.30-33
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• 2006

Onset voltage plays a crucial role in the design of a spray microthruster. This paper presents an analytical electrostatic model to predict the behavior of onset voltage in an array of emitters. The basic idea of this method is to superimpose the electric potentials obtained from each individual emitter in an array of emitters. The results show that if one emitter operates and the other neighboring emitters are dry, the potential required for cone-jet spraying generally increases as the emitter spacing decreases (due to electrical shielding). However at very close spacing the potential can decrease. If all emitters operate at the same time, the phenomenon that even at very close spacing the onset voltage required for cone-jet spraying increases merely as the emitter spacing decreases.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.811-818
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• 2000

Agricultural chemicals spraying is one of the most efficient methods for pesticides control. General farming groups use Speed Sprayer but its deposition amount on practical crops is only 20% of total amount in SS case. Agricultural chemicals which fail to arrive the crops not only cause environmental contamination but loss of agriculture chemicals by lower deposition efficiency. For the purpose of improvement of these problems, this experiment proposes SS attachment type electrostatic induction spraying apparatus with DC power which improves deposition efficiency of agriculture chemicals on the crops.

• 한국식품영양과학회지
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• 제46권8호
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• pp.979-985
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• 2017

본 연구는 유산균에 의한 gamma aminobutyric acid(GABA)의 생산 및 쌀겨 추출물을 이용한 최적 배지의 제조를 목표로 하고 electrostatic spray는 곡물에 GABA 함량을 증진시키기 위해 사용하였다. 분리한 Lactobacillus brevis CFM11을 MRS 배지를 이용하여 최적 조건($37^{\circ}C$, 24시간, pH 6.5)에서 배양시킨 결과, $600.12{\mu}g/mL$의 GABA 생성량을 나타냈고 0.8% MSG를 함유한 MRS 배지에서 배양시켰을 때 $2,002.93{\mu}g/mL$의 GABA 생성량을 나타냈다. 미강 추출물 배지에 MSG 0.4%, sucrose 2%, skim milk 1%, magnesium sulfate 0.2%를 첨가했을 때 GABA 생산량은 $585.80{\mu}g/mL$로 나타났다. 최적화 배지에 L. brevis CFM11을 배양시켜 얻은 GABA를 쌀 표면에 electrostatic spray 처리 후 GABA량은 $228.10{\mu}g/g$으로 나타난 반면, 아무것도 처리하지 않은 곡류에서의 GABA량은 $32.23{\mu}g/g$이었다. 이러한 결과로 보아 미강 추출물은 GABA 생산을 위한 MRS 배지의 대체물로서 산업적인 가치를 증가시킬 수 있을 것으로 판단된다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권9호
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• pp.388-394
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• 2003

Many toxic pesticides as aqueous-base sprays are dispensed for protection of food crops from pests into farm fields. When dispensed with conventional nozzles, a large portion of the spray is often lost by airborne drifts of droplets away and lack of deposition onto the plants due to rapid gravitational settling of droplets to the soil beneath. And target deposition efficiencies poorer than 20％ are often encountered in agricultural pesticides. An electrostatic spraying technology offers a very favorable means to increasing pesticides droplets deposition onto biological surfaces of living crops. In this paper a corona type spray nozzle, utilizing a set of corona charging devices and a pulsed droplet-charging voltage applied, has been proposed and tested its potential experimentally. As a result, it exhibits a large current deposition of aqueous pesticide sprays on the sensing target, which, however, promise to be as one of the effective electrostatic spraying nozzle.