• Current Research on Agriculture and Life Sciences
• /
• v.9
• /
• pp.11-20
• /
• 1991

This study was performed to avoid the chemical spraying environment condition during spraying operation for operator's safety through the development of a remote controlled speed sprayer. The summerized results of this study are as followings. 1. The developed VHF electric wave remote controlling system which could operate sixteen type of operation conditions with the circuit channels of 234 was highly adaptable to speed sprayer for the remote control. 2. The commerical wireless telephones adapted the DTMF type electric wave remote control system need not the tranceiver. 3. The wireless electric wave remote control system combined with one-chip microcomputer, which are low cost with compact in size, could be adaptable to the remote control of the speed sprayer for the wheel steering and speed control system, and to the remote control chemical application system.

• Journal of Korean Society of Forest Science
• /
• v.94 no.4 s.161
• /
• pp.277-280
• /
• 2005

In order to prevent chestnuts from damage by the peach pyralid moth, Dichocrosis punctiferalis, a sprinkler system was installed on the chestnut orchard. Such a test was conducted at Yeoju-gun, Gyeonggi-do, Korea in 2002. Insecticides of fenitrothion 50% EC, x1,000 and diflubenzuron 25% Wp, x2,500 were sprayed at ten-day fifteen-day and twenty-day intervals during the period of D. punctiferalis adult occurrence by sprinkler system. The peach pyralid moths generally emerged for about 60 days from early July to early September, and peak emergence was 10 days from late July to early August. Damage rate of chestnuts were 0.9-4.0% on average with this crown insecticide spraying with diflubenzuron, while 30.4% when not treated. Control effectiveness of this insecticide spraying was 92%(86.7-97.0%). In conclusion, effectual times and number of insecticide application with sprinkle system against peach pyralid moth were from early July to late August and four or five times at ten or fifteen day intervals, respectively.

• Korean Journal of Plant Resources
• /
• v.19 no.1
• /
• pp.93-96
• /
• 2006

In order to prevent cones from being damaged by cone insects, Gravitarmata margarotana and Dioryctria abietella, sprinkler system was installed on the Pinus koraiensis Seed Orchard. Such a test was conducted at Chung-ju, Chungcheong buk-do, Korea in 2002. Insectides of Diflubenzuron 25% WP ${\times}2,500$ and Cyfluthrin 2%EC ${\times}\;1,000$ were sprayed at fifteen-day and twenty-day intervals during the period of insects adult occurrence by sprinkler system. The Gravitarmata margarotana generally emerged for about 53 days from middle April to early June, and peak emergence was 10 days from April 20 to April 30. Dioryctria abietella generally emerged for about 108 days from late April to early August, and peak emergence was 10 days from May 20 to May 30. Damage rate of cones were $8.7{\sim}9.7%$ and $10.9{\sim}12.7%$ on average with crown insecticide spraying with Cyfluthrin and Diflubenzuron, while 67.5% when not treated. Control effectiveness of this insecticide spraying was $85.6{\sim}87.1%$ and 83.9%와 81.2%, respectively. When it considers the forest environment, it is recommended diflubenzuron which is low toxic pesticide. In conclusion, effectual times and number of diflubenzuron 25% WP application with sprinkler system against cone insects were from early May through late August and six times at twenty-day interval.

• Korean Journal of Plant Resources
• /
• v.19 no.5
• /
• pp.598-601
• /
• 2006

In order to prevent chestnut from damaged by the chestnut gall wasp, Dryocosmus kuriphilus, a sprinkler system was installed on the chestnut orchard. Such a test was conducted at Sanchung-gun, Kyeongnam province, Korea in 2003 and 2004. Insecticide of carbaryl 50% WP, x1,500 was sprayed at every day and two-day intervals during the period of D. kuriphilus adult occurrence by sprinkler system. The chestnut gall wasps generally emerged for about 35 days from the middle June to the middle July, and peak emergence was 5 days of early July. Crown application of carbaryl by sprinkler system was found to be highly effective for control of the chestnut gall wasp. Gall formation rate of chestnut were 3.0 and 12.8% on average with crown insecticide spraying at every day and two-day intervals, while 82.9% when not treated. Control effectiveness of this insecticide spraying was 96.4% and 84.6%, respectively.

• Journal of the Korea Institute of Building Construction
• /
• v.16 no.2
• /
• pp.107-115
• /
• 2016

In this study, the bond strength of metal spraying system by surface treatment of concrete (waterproof/corrosion method) in water treatment facilities was evaluated. The results showed that the system with Sa-P-R-(S) (sanding-perviousness surface hardener-surface roughness agent-metal spraying-sealing) led to the desirable performance. The bond strength, the coefficient of water permeability and air permeability were 3.7MPa, $0.68{\ast}10^{-8}cm/sec$, and $0.45{\ast}10^{-16}m^2$, respectively. In scanning electron microscope analysis, the microstructure of specimen coated with perviousness surface hardener was much denser than that without it. Therefore, the specimen coated with sanding-perviousness surface hardener-surface roughness agent-metal spraying-sealing had the best bond performance and was the most suitable system to concrete surface in water treatment facilities.

• Journal of Biosystems Engineering
• /
• v.37 no.5
• /
• pp.287-295
• /
• 2012

Purpose: Some of the most representative approaches are to apply next generation technologies to save energy consumption, fully automated control system to appropriately maintain environmental conditions, and autonomous assistance system to reduce labor load and ensure operator's safety. Nevertheless, improvement of upcoming method for soil cultured greenhouse has not been sufficiently achieved. Geometrical complexity of ground in protected crop cultivation might be one of the most dominant factors in design of autonomous vehicle. While there is a practical solution fairly enough to promise an accurate travelling, such as autonomous sprayer guided by rail or induction coil, for various reasons including the limitation of producer's budget, the previously developed sprayer has not been widely distributed to market. Methods: In this study, we developed an autonomous sprayer considering travelling performance on geometrical complexity of ground in soil cultured greenhouse. To maintain a stable travelling and to acquire a real time feedback, common wire with 80 mm thick and body frame and sprayer boom. To evaluate performance of the prototype, tracking performance, climbing performance and spraying boom's uniform leveling performance were individually evaluated by corresponding experimental tests. Results: The autonomous guidance system was proved to be sufficiently suitable for accurate linear traveling with RMS as lower than approximately 10 cm from designated path. Also the prototype could climb $10^{\circ}$ of ground's slope angle with 40 kg of water weight. Uniform leveling of spraying boom was successfully performed within $0.5^{\circ}$ of sprayer boom's slope. Conclusions: Considering more complex pathways and coarse ground conditions, evaluations and improvements of the prototype should be performed for promising reliability to commercialization.

• Korean Journal of Materials Research
• /
• v.30 no.10
• /
• pp.533-541
• /
• 2020

UO₂ kernels, a key component of fuel elements for high temperature gas cooled reactors, have usually been prepared by sol-gel methods. Sol-gel processes have a number of advantages, such as simple processes and facilities, and higher sphericity and density. In this study, to produce 900 ㎛-sized UO₂ particles using an external gelation process, contact length extension of the NH₃ gas of the broth droplets pass and the improvement of the gelation device capable of spraying 14 M-NH₄OH solution are used to form 3,000 ㎛-sized liquid droplets. To produce high-sphericity and high-density UO₂ particles, HMTA, which promotes the gelation reaction in the uranium broth solution, is added to diffuse ammonium ions from the outside of the gelation solution during the aging process and generate ammonium ions from the inside of the ADU gel particles. Sufficient gelation inside of ADU gel particles is achieved, and the density of the UO₂ spheres that undergo the subsequent treatment is 10.78 g/㎤; the sphericity is analyzed and found to be 0.948, indicating good experimental results.

• Journal of Welding and Joining
• /
• v.17 no.4
• /
• pp.53-59
• /
• 1999

Amorphous alloys have also been called glassy alloys or non-crystalline alloys. They are made by the rapid solidification. The solidification occurs so rapid that the atoms are frozen in their liquid configuration. There are unique magnetic, mechanical, electrical and corrosive behaviors which result form their amorphous structure. In the study. amorphous coatings were manufactured with Ni-Cr-B-Si powders by flame spray. Measurement of hardness, were resistance, corrosion resistance and observation of microstructures and XRD, DSC were performed to investigate characteristics of amorphous coatings. The experimental results obtained as follow: 1) Amorphous powders could not be manufactured with the spraying in the spraying in the liquid nitrogen. But, amorphous coatings could be manufactured with the rotation cooling method by liquid nitrogen. In the fabrication of amorphous coatings, major factor was the rapid cooling by rotation of the substrate. 2) Hardness of coatings was obtained Hv 960 by formation of amorphous phase. But, wear resistance decreased. That was due to porosity in the coatings by the rapid cooling. 3) In the case of corrosion resistance, amorphous coatings were superior to air-cooled coatings. That was due to formation of amorphous phase. 4) After amorphous coatings were heat-treated at 520℃ for 1hr. hardness increased 80% and wear resistance increased 30% comparing with air cooled coatings. These were due to crystallization of amorphous phase and decrease of porosity by heat-treatment.

• Journal of Biosystems Engineering
• /
• v.22 no.2
• /
• pp.137-150
• /
• 1997

To investigate the feasibility of a boom sprayer in the paddy field, an experimental boom sprayer for both broadcast and directed spraying to the lower part of rice plants was developed. The droplet deposition characteristics of the boom sprayers were experimentally compared to those of power sprayer. Water sensitive papers(WSP) and a machine vision system were used to evaluate the coverage rate and droplet density. It was shown that the broadcast application by the boom sprayer was the best coverage among the tested sprayers. Coverage tate and droplet density were affected by the distance between nozzles and the sprayer ground speed, The best result was obtained when the distance of 30cm and the speed of 1.7km/hr. The directed application showed inconsistency in overall droplet distribution. The inconsistency was judged to be caused by conflict between plants and boom extenders. The power sprayer showed a very wide range of droplet size distribution, relatively larger droplets and inconsistency in cove The power sprayer was judged to be inadequate for the low-volume precision application because of inconsistency in performance and difficulty in adjusting the spraying rate. Based on the droplet coverage characteristics, it was concluded that the self-propelled boom sprayer for the broadcast application was feasible for an alternative to the power sprayer in case of low volume, precision application in paddy condition.

• Journal of Animal Environmental Science
• /
• v.13 no.1
• /
• pp.29-34
• /
• 2007

This study was conducted to develop a reclaimer of the vehicle disinfector to be used at livestock fm. The reclaimer was mainly consisted of ball-valves, geared motors and one-chip processor, and the purpose of the system was to prevent liquid freezing as well as decrease environmental pollution of antiseptic solution. The properly spraying pressure of the vehicle disinfector was found over 1.96 MPa at 1m of the spraying range. While certain amount of the antiseptic solution remained in the injection-pipes, the spray starting time was found not making any significant effect on the remained amount of the antiseptic solution. The amounts of the antiseptic solution remained in the injection-pipes were 50 ml and 270 ml in average, respectively with and without the use of the reclaimer. The reclaimer was the most effective when the connection of the injection-pipe and sprayer line was located below the side-injection-pipe and then connected to the injection-pipe located at the bottom of vehicles.