• Title/Summary/Keyword: Spraying time

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Dissipation and Processing Factor of Etofenprox and Fenitrothion Residue in Chinese Matrimony Vine by drying (건조에 따른 구기자 중 etofenprox와 fenitrothion의 잔류량 변화 및 가공계수)

  • Noh, Hyun Ho;Lee, Jae Yun;Park, Hyo Kyoung;Jeong, Hye Rim;Lee, Jung Woo;Jo, Seung Hyeon;Kwon, Hyeyoung;Kyung, Kee Sung
    • Korean Journal of Environmental Agriculture
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    • v.37 no.3
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    • pp.213-220
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    • 2018
  • BACKGROUND: This study was carried out to determine characteristics of residual pesticides in time-dependent manner and calculate half-lives of the residual pesticides in fresh and dried Chinese matrimony vine. In addition, processing factors were calculated based on the residual concentrations in them. METHODS AND RESULTS: The test pesticides, etofenprox and fenitrothion, were sprayed onto the Chinese matrimony vine plants at once or twice (at seven-day interval) and then samples were collected at 0 (after 3 hours), 1, 3, 5 and 7 days after the last spraying. Dried samples were prepared in hot-air drying oven at $60^{\circ}C$ for 48 hours until water content of less than 20%. Residual concentrations of etofenprox in fresh and dried samples decreased by 54.0-60.9% after 7 days of the last pesticide-application. In case of fenitrothion, the concentrations were found to have decreased by 69.2-76.5%. Processing factors of etofenprox were 2.6-3.0 for the one-time spraying and 2.5-3.0 for the two-time spraying and those of fenitrothion were found to be 1.5-22 for the one-time spraying and 1.6-2.0 for the two-time spraying. First half-lives of etofenprox and fenitrothion in fresh and dried samples ranged from 5.0 to 6.3 and from 3.4 to 4.0 days, respectively. The third half-lives were found to be 15.0-18.9 and 10.2-12.1 days, respectively. CONCLUSION: Residual concentrations of the tested pesticides in the studied crop decreased, but those in the dried samples appeared to have increased. In addition, processing factor and half life were constant regardless of spraying times.

Performance Evaluation and Improvement of Medium and Small Scale Rice Polishers(I)-small scale rice polishers- (중.소형 연미기의 성능평가 및 성능개선에 관한 연구(I)-소형 연미기에 대하여-)

  • 정종훈;최영수;권홍관
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1998.06b
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    • pp.206-216
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    • 1998
  • The structural characteristics of small scale rice polisher was analyzed to improve its performance. Spraying characteristic of nozzles used for rice polishing was also analyzed by a machine vision system. The internal pressure of the polishing chamber was measured according to outlet resistance, water spraying , and roller shaft speed. In addition , the performance of the rice polisher was evaluated to improve it in the basis of internal pressure in polishing chamber, whiteness , and broken rice ratio of clean rice according to the operating conditions. Actual nozzle discharge rate and drop size were 125cc/min and 86.97㎛, respectively. In the case of water spraying on rices, the internal pressure showed 4.9-9.8N/㎠ increase, broken rice ration decreased , and there was no difference in whiteness . The internal pressure increased up to two time with the increase of the outlet resistance. Also, the pressure at the upper part of screen was one and half times as high as the pressure at the lower part. In the case of water spraying rate of 150 cc/min, the roller shaft speed of 850 rpm resulted in no difference in whiteness and decrease of 0.3%in broken rice ratio, comparing to the roller shaft speed of 950 rpm.

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A Socio-medical Study on the Usage and Poisoning of Pesticides (농약의 사용과정과 중독에 관한 사회의학적 고찰)

  • Cha, Min-Young;Cha, Hyung-Hun;Yum, Yong-Tae
    • Journal of agricultural medicine and community health
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    • v.9 no.1
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    • pp.18-26
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    • 1984
  • With the increase of using pesticides, pesticide poisonings become more frequent. In the previous epidemiological study on pesticide poisoning and the reports of the authorities concerned, it is carefully affirmed that pesticide poisonings are caused by farmers' ignorance and negligence in using the pesticides. But the pesticide poisoning should be taken into account in terms of the person who sprays the pesticides, its spraying process, farming style and farmers' socio-economic conditions. And based on the understanding mentioned above, preventive measures for pesticide poisoning should be established. In this socio-medical point of view, this study examined the public health problems caused by using pesticides and the treatment of pesticide poisoning, based on the interviews with farmers in a area of Kyunggi-Do about the spraying process of pesticides, poisoning experiences and its treatments. The results are as follows ; 1) The style of spraying pesticides in the target area is mostly an individual one, not cooperative one. And the subjects of spraying are householders, whose educational backgrounds are beneath notice. More than 2~5 of the subjects are women or old men of 60 years old or so. These are seen to derive from the socio-economic status of Korean agricultural families; their younger generation's moving to greater cities and their petty farming styles. 2) As for the safety measures for the spraying of pesticides, those which have nothing to do with the economic, problems such as efficient spraying and productivity, are well obeyed. On the other hand, some safety measures as the use of safety devices, and spraying time, the degree of dilution of pesticides and the spraying method In windy days, are not obeyed very well, for to keep those makes spraying difficult to do and productivity worse. These facts indicate that the safety measures for using pesticides must be directly concerned with the spraying process, farming style and farmers' socio economic status, rather than the subject's knowledge or carefulness. 3) Even In cases of poisoning they do rarely consult the doctors. This is caused by the problem of their locality and transportation since one should pass away a day even in the busiest season to consult doctors, and by their low socio-economic status. 4) The epidemiological studies on pesticide poisonings should be necessarily led to a socio-medical one which are concerned together with the spraying process of pesticides, farming style, farmer's socio-economic status and discrepancies in public health policies between agricultural communities and urban ones.

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Polishing Characteristics and Development of Automatic Die Polishing Machine by Liquid Honing (액체호닝에 의한 금형 자동 사상기계개발 및 가공 특성)

  • 김재도;류기덕;홍정석
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.6
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    • pp.162-168
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    • 2000
  • The automatic die polishing machine by liquid honing has been developed and experimented on the surface of machined die. The goal of development in the automatic die polishing machine by liquid honing is to increase the accuracy and the productivity in die polishing. To reach this goal, the polishing machine consists of the automatic measuring device for contour of die, the nozzle and pumping system to spray the powder mixed with liquid, and the 3-axis guides. Before polishing, the measuring device with a semiconductor laser scans the surface of mould to get the data of contour. The data store a PC and use to control the nozzle head to move above a couple of centimeters on the machined surface of die. The experimental parameters are the spraying time, the pressure, the size of abrasive grain and the mixing ratio between abrasive grain and liquid. The surface roughness is measured on the polished die which are SKDl 1 and Al7075 machined by NC. The surface roughness indicates the values of Rmax 0.5${\mu}{\textrm}{m}$ for Al7075 and Rmax 1.4${\mu}{\textrm}{m}$ for SKDl 1. It reduces the polishing time significantly and reduces the monotonous work for labors. As the results, the liquid honing system is useful method to apply for the die polishing and the automatic die polishing machine using liquid honing shows that it's very effective processing ability.

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Microstructure and Pore Characteristics of a SUS316L Gas Filter Fabricated by Wet Powder Spraying

  • Min-Jeong Lee;Yu-Jeong Yi;Hyeon-Ju Kim;Manho Park;Jungwoo Lee;Jung-Yeul Yun
    • Archives of Metallurgy and Materials
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    • v.67 no.4
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    • pp.1547-1550
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    • 2022
  • In this study, a flake-shaped metal powder was coated on a tube shaped pre-sintered 316L stainless steel support using a wet powder spraying process to fabricate a double pore structure, and the pore characteristics were analyzed according to coating time and tube rotation speed. The thickness of the coated layer was checked via optical microscopy, and porosity was measured using image analysis software. Air permeability was measured using a capillary flow porometer. As a result of the experiment, the optimal rotation speed of the support tube was established as 200 rpm. When the rotation speed was fixed, the coating thickness and the coating amount of the double pore structure increased as the coating time increased. The porosity of the double pore structure was increased due to the irregular arrangement of the flake-shaped powder. The air permeability of the double pore structure decreased with increasing fine pore layer thickness.

Optimization of Fugitive Dust Control System for Meteorological Conditions (기상조건별 비산먼지 관리체계 최적화 연구)

  • Kim Hyun-Goo
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.6
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    • pp.573-583
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    • 2005
  • Fugitive dust, which is emitted in the ambient air without first passing through a stack or duct designed to control flow, is frequently generated by means of wind erosion from storage yards at Pohang Steel Wokrs. The size distribution of fugitive dust is mostly in the range of coarse particulate which is deposited as soon as emitted and less harm to human health; however $20\%$ of fugitive dust contains PM 10 known as one of most harmful airborne pollutant. Consequently, effective control and reduction of fugitive dust is strongly requested by the local society, but it is not easy so far because the generation and dispersion of fugitive dust highly depends on meteorological conditions, and it being occurred for irregularity. This research presented a fugitive dust control system for each meteorological condition by providing statistical prediction data obtained from a statistical analysis on the probability of generating the threshold velocity at which the fugitive dust begins to occur, and the frequency occurring by season and by time of the wind direction that can generate atmospheric pollution when the dispersed dust spreads to adjacent residential areas. The research also built a fugitive dust detection system which monitors the weather conditions surrounding storage yards and the changes in air quality on a real-time basis and issues a warning message by identifying a situation where the fugitive dust disperses outside the site boundary line so that appropriate measures can be taken on a timely basis. Furthermore, in respect to the spraying of water to prevent the generation of fugitive dust from the storage piles at the storage yard, an advanced statistical meteorological analysis on the weather conditions in Pohang area and a case study of fugitive dust dispersion toward outside of working field during $2002\∼2003$ were carried out in order to decide an optimal water-spraying time and the number of spraying that can prevent the origin of fugitive dust emission. The results of this research are expected to create extremely significant effects in improving surrounding environment through actual reduction of the fugitive dust produced from the storage yard of Pohang Steel Works by providing a high-tech warning system capable of constantly monitoring the leakage of fugitive dust and water-spray guidance that can maximize the water-spraying effects.

Development of a Flow Compensating Boom Sprayer for the Speed Variation (주행속도 보상형 붐방제기의 개발)

  • 구영모;정재은
    • Journal of Biosystems Engineering
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    • v.23 no.3
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    • pp.211-218
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    • 1998
  • A variable flow-controlled boom sprayer was developed and evaluated. Field tests were conducted to evaluate the adoptability of the sprayerr with optimal conditions. Negative response time was obtained from the field test because pump and PTO were interlocked with the speed of sprayer. Another reason for the negative value was due to the definition of the response time. With constant on-time control, the system was unstable at the conditions of small tolerance and long control interval. The performances of the spray system were stable and accurate. The stable and synchronous responses were achieved with a variable on-time control. The flow control system with an optimal condition (1.0 sec of control interval, 2 of damping ratio, 1% of tolerance) provided the proper performance for uniform spraying. A standard operating procedure of the flow compensating boom sprayer for the ground speed variation was presented and recommended.

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Evaluation of Cooling Effects in Greenhouses with Mist System at Variations of Spraying or Non-spraying Time Durations (미스트 분무시간 및 휴지시간 변화에 따른 하우스 냉각효과 검토)

  • 허종철;최동호;임종환;서효덕
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 1999.11a
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    • pp.59-62
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    • 1999
  • 1. 미스트를 장시간 분사시킬 경우 분사기간동안 온도강하는 분사량에 무관하게 일정하나 분사종료 후 온도상승은 분사량이 많으면 온도상승이 현저히 지연된다. 반면 증가된 습도는 장시간 유지되기 때문에 적정 분사량이 존재한다. 2. 시설하우스내 고온장애와 습도장애를 극복하고 보다 유리한 실내환경을 유지하기 위해서는 적정 미스트 분무량을 유지시켜야 하며 동시에 분무시간과 휴지시간을 충분히 고려해야만 한다.

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Chemical Control of bacterial Canker of Kiwifruit (참다래 궤양병의 약제 방제)

  • 고영진
    • Plant Disease and Agriculture
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    • v.5 no.2
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    • pp.95-99
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    • 1999
  • Chemical control of bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae was attempted by spraying of streptomycin sulfate ·oxytetracycline WP streptomycin WP streptomycin ·copper hydroxide WP kasugamycin SL kasugamycin·copper oxychloride WP and copper hydroxide WP. The control efficacies of the bactericides were variable depending upon the spraying schedule,. Application of streptomycin WP and streptomycin sulfate·oxytetracycline WP from middle April to early May was found to be the most effective in controlling the bacterial canker. For copper hydroxide WP the spraying from middle January to early February showed the highest control efficacy. Kasugamycin SL was the most effective in controlling the disease by spraying from middle April to early May but it was still relatibvely effective during other spray periods. Foliar application of copper hydroxide WP and copper-antibiotic formulaions after middle April caused severe phytotoxicity. Kasgamycil SL streptomycin WP streptomycin·copper hydroxide WP and copper hydroxide WP were potential bactericides which could substitute streptomycin sulfate·oxytetracycline WP. Selective applications of the bactericides according to their optimum spray time can enhance the control efficacies against bacterial canker of kiwifruit and retard the emergency of resistant strains of P. syringae pv. actinidiae to the bactericides. The optimum spray number of streptomycin sulfate·oxytetracycline WP was 3 times with 15-day-intervals or 4 times with 10-day-intervals. The result suggested that the potential bactericides to bacterial canker of kiwifruit should be also used according to their optimum spray schedules in order to get their highest control efficacies.

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Research on the Variable Rate Spraying System Based on Canopy Volume Measurement

  • Hu, Kaiqun;Feng, Xin
    • Journal of Information Processing Systems
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    • v.15 no.5
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    • pp.1131-1140
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    • 2019
  • Characteristics of fruit tree canopies are important target information for adjusting the pesticide application rate in variable rate spraying in orchards. Therefore, the target detection of the canopy characteristics is very important. In this study, a canopy volume measurement method for peach trees was presented and a variable rate spraying system based on canopy volume measurement was developed using the ultrasonic sensing, one of the most effective target detection method. Ten ultrasonic sensors and two flow control units were mounted on the orchard air-assisted sprayer. The ultrasonic sensors were used to detect the canopy diameters and the flow controls were used to modify the flow rate of the nozzles in real time. Two treatments were established: a constant application rate of $300Lha^{-1}$ was set as the control treatment for the comparison with the variable rate application at a $0.095Lm^{-3}$ canopy. The tracer deposition at different parts of peach trees and the tracer losses to the ground (between rows and within rows) were analyzed in detail under constant rate and variable rate application. The results showed that there were no significant differences between two treatments in the liquid distribution and the capability to reach the inner parts of the crop canopies.