• Journal of Biosystems Engineering
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• 제27권2호
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• pp.143-150
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• 2002

Several researches for site-specific weed control have tried to increase accuracy of weed detection with machine vision technique. However, there is a problem which needs substantial time to perform site-specific spraying. Therefore, new technology for real-time precision spraying system is needed. This research was executed to develope the new technology to estimate weed density and size in real time, and to conduct a real-time site-specific spraying. It would effectively reduce herbicide amounts applied for a crop field. The real-time precision spraying system consisted of a Differential Global Positioning System (DGPS) with an error of 2 cm, a machine vision system, a geomagnetic sensor for correction of view point of CCD camera and an automatic sprayer with separately controlled nozzle. The weed density was calculated with comparison between position information and a pre-designed electronic map. The position information was obtained in real time using the DGPS and the machine vision. The electronic map contained a position database of crops automatically constructed when seeding. The developed system was tested on an experimental field of Seoul National University. Success rate of the spraying was about 61%.

• Design & Manufacturing
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• 제13권2호
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• pp.49-53
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• 2019

The temperature distribution and lifetime of molds were predicted by computer simulation analysis with various spraying and blowing process of high pressure die casting. After varying the spraying angle and time, the mold temperature, heat exchange and mold life were predicted. As the spraying angle increases, the maximum temperature of the mold decreases, which is because the spraying area increases and the heat exchange with the mold increases. Heat exchange occurs more actively in the blowing process than in the spraying process. This is because the cooling is not performed due to the steam generation. When the spraying angle is 50 degree, the minimum life of the mold is analyzed 200 times. After adjusting the blowing time from 5s to 3s, the minimum lifetime of the mold has been increased almost twice.

• 한국표면공학회지
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• 제22권1호
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• pp.26-42
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• 1989

It has between investigated that the optimum spaying conditions, such as, spraying distance, fusing temperature and fusing time, ect, in a Ni-cr base self fluxing alloy sprayed on the mild steel substrate by oxygen-acetylenc flame spraying. Sprayed specimens on various conditions were fuused in a vacuum furnace and the results were as follows. The optimum spraying condition for excellent coating layer are obtained under spraying distances, fusing temperature and fusing and time ; 180~240mm,1050~110$0^{\circ}C$and 15~30min, respectively. The adhesive strength and surface hurface hardness of the as sprayed specimens were very low by mechanical bonding becaus of the diffusion layer during process. The carbides and borides and formed in the sprayed coating layer and densification of the layer was resulted from the elimination of pores and oxides. The hardness of sprayed coating layer, particularly in the high temperature, was superior to ordinary tool steels.

• 한국분무공학회지
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• 제13권4호
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• pp.212-219
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• 2008

To develop the twin-fluid atomizer having the excellent performance of painting, the spray characteristics of how a wide area can be painted efficiently by one time spraying were studied in this paper. Spray phenomena are affected by the many factors determining the spray field such as the spraying pressure of gas, the spraying pressure and viscosity of liquid paints, the opening duration of needle valve, the design dimension of nozzle, and so on. As the results of experiments, these factors affecting on spray characteristics were suggested as followings; 1) The optimum spraying pressure of gas was $0.015{\sim}0.02\;kPa$, and the appropriate spraying pressure of liquid paint was 0.01kPa, In these situations, the setting up pressures must be compensated as much as the losing amount of pressure because a decompression occurred when operating valves. 2) The duration of opening the needle valve must be sustained for $1{\sim}2$ seconds to inject gas after spraying the liquid paint. This operating of the needle valve was necessary to avoid the affect on the changing of liquid column length, and to prevent the droplet deposit at the initial time of spraying. 3) The spray tip penetration was gained form the experimental equation, and the effective spraying angle was $85^{\circ}{\pm}5^{\circ}$ just at he appropriate spraying pressure of gas. The distribution of the area sprayed had the variation in $350{\pm}50\;mm$ because of the spraying pressure of gas, the its distance from the spray tip, and the lift of the needle valve.

• Journal of Biosystems Engineering
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• 제38권4호
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• pp.228-239
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• 2013

Purpose: The objectives of this study were to develop an automated disinfectant dilution system, and an automated data management system for spraying amount for resolving uncertainty problem. Methods: Proper diluting rate was made by a controlled volume pump for liquid disinfectant and a screw conveyer pump for solid disinfectant. The water capacity of disinfecting system of 400 L was controlled by two water level sensors. The water quantity of water tank was controlled by the signals which were produced by the water level sensors. Signals were processed by Labview Programming, and ON/OFF of solenoid valve that was used for controlling water supplying to water tank, was controlled by SSR. The operating time of pumps for disinfectant was controlled quantitatively. A turbine flowmeter was used for development of automated measurement system for spraying amount of disinfectant. In order to save the flowmeter data and to control the spraying system, a multi-function data logger was used, and it was processed and saved in Excel file by a program developed in this study. Results: Labview 2010 was used for programming to control the automated measurement system for spraying amount of disinfectant. Results showed that the relationship between flowmeter value and time had a significant linear relationship such as 0.99 of $R^2$. Generally, 6.74 L/s of diluted disinfectant is sprayed for a vehicle passing through the disinfection system (about 15 seconds). Test results showed that average error between the measured spraying amount and the flowmeter data was 50 mL, and the range of error was 1.3%. Since the amount and time of spraying could be saved in real-time by using the spreadsheet files which could not be modified arbitrarily, it made possible to judge objectively whether the disinfection spraying was performed or not. Test results of spraying liquid and solid disinfectant showed that the errors between the measured discharge rate and the theoretical one were ranged within 3-4% for various dilution rates. Conclusions: The disinfection system developed would be working accurately. The automated spraying data base management system satisfied the purpose of this study. The automated dilution process system developed in this study could discharge liquid and solid disinfectant with accurate dilution rate, relatively.

• 한국잠사곤충학회지
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• 제13권2호
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• pp.95-97
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• 1971

추잠기 수확직후 가지의 선단 잔엽에 MH (Maleic hydrazide) 살포가 내한성 증대에 미치는 영향을 시험하여 다음과 같은 성적을 얻었다. 1. 0.25% 이상의 농도로 살포하면 저장전분이 증가되고 이듬해 봄에 가지의 선단고사비율이 낮아졌다. 2. 중부지방에서의 살포적기는 9월중순경이다. 3. 우량 뽕나무인 일지뢰, 개량서반, 노상, 수원상4호는 MH의 살포효과가 인정되었다. 4. 품종간의 내한성 정도는 수원상4호＞개량서반＞일지뢰＞노상 순으로 강하였다.

• 한국진공학회지
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• 제6권S1호
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• pp.160-165
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• 1997

Yttria stabilized zirconia coating is an attractive material for several engineering applications. In order to produce coatings with consistent and reliable performance it is important to understand the influence of spraying parameters on the coating properties and optimize the spraying parameters. In this paper the low pressure plasma spray(LPPS) deposition of as-received zirconia powder has been investigated using simple one-factor-at-a-time approach. The deposition efficiency was chosen to evaluate the melting characteristics of the as-received zirconia powder. The results obtained indicated that the deposition efficiency of zirconia powder is very sensitive to the spraying parameters such as plasma gas flow rate and ranges from 24% to 57% The microstructure and the phase composition of zirconia coating deposited with the different plasma spraying parameters were also examined by SEM and XRD respectively. The relationship between deposition efficiency and the microstructure of zirconia coating was discussed.

• 생물환경조절학회지
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• 제31권1호
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• pp.52-59
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• 2022

시설재배 온실에서 병해충 방제를 위해 자율적으로 이동하면서 작물에 농약을 살포할 수 있는 무인 자동 농약 살포 시스템을 이용하여 방제처리를 실시하였다. 토마토, 딸기의 총채벌레(Frankliniella occidentalis)와 온실가루이(Trialeurodes vaporariorum) 해충에 대한 방제효과를 조사한 결과, 꽃노랑 총채벌레의 방제효과는 토마토에서 85.6%, 딸기에서 87.5%로 나타났고, 온실가루이는 각각 81.7%와 80.6%를 나타내었다. 또한 약제처리 방법에 따른 방제효과는 관행약제살포 처리구 81.7%, 무인 자율 약제 살포처리구 83.9%의 방제효과를 나타내었다(F=22.1, p < 0.001). 두 처리구간 방제효과 비교 시 현저한 유의성은 나타나지 않았으나 무인 자율 약제 살포처리에서 2.2% 높은 효과를 나타내었다. 한편, 약제 살포 시간을 비교한 결과, 무인 자동 약제 살포기는 살포시간이 5min/10a으로 관행 약제 살포시간 25-30min/10a 보다 25min 정도 적게 소요되었다. 이러한 결과는 발생최성기에 시설온실에서의 효율적인 해충 방제로 무인 자동 약제 살포방제법이 유용하게 사용될 수 있을 것으로 판단되었다.

• Mass Spectrometry Letters
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• 제6권1호
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• pp.21-25
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• 2015

In this paper, I describe the importance of matrix spraying conditions in imaging mass spectrometry (IMS) to obtain successful imaging results. My developed matrix application methodology, which is a "two-step matrix application" sequentially combined with matrix sublimation and spraying matrix solution can provide high reproducibility and high ion yield compared with a conventional direct spraying method. However, insufficient IMS results were obtained occasionally despite the two-step method. Therefore, I wanted to characterize the methodology to continuously provide high quality data. According to my results, the sublimation time was not a strict parameter, and the most important step was the first spraying condition. This means that the extraction conditions from the tissue section and co-crystallization of the matrix were the most important factors.

• 약학회지
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• 제39권6호
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• pp.593-599
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• 1995

Erythromycin was formulated as enteric-coated pellets in order to reduce degradation in stomach and gastromtestmal irritation, and to maximize the absorption in intestine followmg its oral administration. Core pellets were prepared using fluid-bed granulator with two different methods (powder layering and solvent spraying) and enteric-coated with two different coating polymers (HPMCP and Eudragit E30D). Physical characteristics md dissolution rates of core pellets and enteric-coated pellets were evaluated to optimize the formulation. Powder layering method resulted in shorter initial dissolution time than solvent spraying method, but physicochmical properties of the product were worse than solvent spraying method with respect to hardness, ftiability and density. The dissolution rate of the drug was increased with the addition of surfactants, showing concentration-dependence. The scanning electron microscopic observation of pellets revealed significant differences on the surface appearances prepared with solvent spraying method. The core pellet made with powder layering method had crystals on the surface, which resulted in poor physical properties of the pellets. The dissolution profiles of erythromycin pellets coated with HPMCP or Eudragit L30D were close to that of commercially available erythromycin enteric-coated product.