• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.116-121
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• 2000

Photosensitizing activities of some selected photosensitizers (PS) on the artificial diminution of pesticide residues on red pepper were investigated. Red peppers were sprayed 4 times with the three fungicides, dithianon, triflumizole, and triforine, according to the conventional method, followed by the application of photosensitizers once. Recoveries for the analyses of the pesticide residues were high $(90.7{\sim}98.5%)$ except for dithianon $(76.6{\sim}78.3%)$. In case of dithianon, after 1 day of the application of PS-1 (10 ppm), the residual amount was 76% of that of the control. For triflumizole, the residual amount after 3 days of the application of PS-4 (50 ppm) accounted for 48% of that of the control. In case of triforine, the residual amount after 1 day of the application of PS-3 (100 ppm) was 55% of that of the control. The results indicated that the photosensitizing activities of photosensitizers varied with chemicals and the matrices where pesticide residues are remaining.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.149-160
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• 2021

BACKGROUND: Concerns have been raised about the impact of recent high concentrations of fine dust on human health. Ammonia(NH₃) reacts with sulfur oxides and nitrogen compounds in the atmosphere to form ultrafine ammonium sulfate and ammonium nitrate (PM2.5). There is a growing need for accurate estimates of the amount of ammonia emitted during agricultural production. Therefore, in this study, ammonia emissions generated from the cultivation of leafy perilla in plastic houses were determined. METHODS AND RESULTS: Cow manure compost, swine manure compost, and poultry manure compost each at 34.6 ton ha^-1, the amount commonly used by farmers in the field, was sprayed on the soil surface. Just after spraying cow manure compost, swine manure compost, and poultry manure compost, the ammonia was periodically measured and analyzed to be 22.5 kg ha^-1, 22.8 kg ha^-1, and 85.2 kg ha^-1, respectively. The emission factors were estimated at 70.0 kg-NH₃ ton-N, 62.8 kg-NH₃ ton-N, and 234.1 kg-NH₃ ton-N, respectively. Most ammonia was released in the two weeks after application of the compost and then the amount released gradually decreased. CONCLUSION: Therefore, it is necessary to improve the emission factor through a study on the estimation of ammonia emission by type of livestock manure and major farming types such as rice fields and uplands, and to update data on the production, distribution, and sales of livestock manure.

• Journal of Biosystems Engineering
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• v.38 no.4
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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.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.350-357
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• 2014

We studied on pesticide residue and pest control effect when using various types of sprayers on paprika cultivation. Additionally, a test was conducted to optimize chemical content per unit area in condition of optimum pest control. Two types of sprayer were tested (three times) on paprika cultivation which was divided into seven sections. Blind spots were also examined using a water sensitive paper when spraying chemical pesticide, remote controlled sprayer were confirmed to be not effective in terms of its spraying capacity. However, a U-shaped sprayer was confirmed that it sprayed enough on all the parts of a plant in green house including the blind spots. Additionally, it does not exceed the minimum residue limits on the all parts of pesticides residue conditions. When using remote controlled sprayer, water sensitive paper were changed to blue color (82.5% and 81.2%) in terms of controlling Bemisia tabaci and Aphis gossypii based on the two spraying manners. 53.0% and 42.6% of control effect were shown on the fair parts of the plants. However, on the poor parts on which pesticides were not well-sprayed, thus, not-remained, more number of pests increased. Meanwhile, on farming that only one type of pesticide has been used, resistance pests present with very low control effect, even though sufficient amount of pesticide was well-sprayed. On the test of the optimum amount of spraying per a unit area, which shows no differences in the two cases of using 5L and 2.5L of chemical pesticides on 9 plants of paprika that has 81.8% and 84.5% control effect, respectively.

• Korean Journal of Environmental Agriculture
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• v.31 no.2
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• pp.152-156
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• 2012

BACKGROUND: This research has investigated the residue patterns of insecticide flubendiamide on three species of peaches with different surface forms, and the residue amounts of them when mixed with a spreader. METHODS AND RESULTS: Pesticide used for field application on peaches was 20% flubendiamide of suspension concentrate(SC) and was sprayed at a recommended rate. The residue amounts of flubendiamide in peach were analyzed by HPLC equipped with UV detector. After the observation with a microscope, the rank of fuzz amount on peach's surface was Kurakatawase, Wolmi in descending order and Cheonhong did not have any fuzz. The residue amounts of flubendiamide were 0.54 mg/kg for Kurakatawase, 0.43 mg/kg for Wolmi and 0.10 mg/kg for Cheonhong, respectively. When flubendiamide was used with a spreader, polyoxy ethylene methylpoly siloxane, the residue amount for Kurakatawase barely changed at 0.55 mg/kg regardless of mixing with a spreader, and at 0.53 mg/kg for Wolmi. In Cheonhong, the residue amount was 0.48 mg/kg, which increased by 4.8 times due to the use of a spreader. CONCLUSION: This result indicates that the residue amounts of flubendiamde were affected by the surface forms of peaches, and in the presence of a spreader the residue amount did not increase in fuzzy species, but was affected greatly for species without fuzz.

• Journal of Korea Foundry Society
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• v.14 no.6
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• pp.530-540
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• 1994

Aluminium-silicon alloy(JIS AC8A) matrix composites reinforced with SiC particles were fabricated by spray-cast forming process, and the microstructure of powders and preforms produced were studied by using an optical and scanning electron microscopy. SiC particles were co-sprayed by mixed phase injection method during the spray casting process. Most of the composite powders formed by this mixed phase injection method exhibit morphology of particle-embedded type, and some exhibits the morphology of particle attached type due to additional attachment of the SiC particles on the surface of the powders in flight. The preforms deposited were resulted in dispersed type microstructure. The pre-solidified droplets and the deposited preform of SiC-reinforced aluminium alloy exhibit finer equiaxed grain size than that of unreinforced aluminium alloy. Eutectic silicons of granular type are crystallized at the corner of the aluminum grains in the preforms deposited, and some SiC particles seem to act as nucleation sites for primary/eutectic silicon during solidification. Such primary/eutectic silicons seem to retard grain growth during the continued spray casting process. It is envisaged from the microstructural observations for the deposited preform that the resultant distribution of SiC injected particles in the Al-Si microsturcture is affected by the amount of liquid phase in the top part of the preform and by the solidification rate of the preform deposited.

• Journal of Environmental Science International
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• v.15 no.11
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• pp.1035-1043
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• 2006

Large scale of fish kills by red tides has been occurred every year in coastal water fisheries of Korea. To suppress red tide spreading out over the south coastal water of the Korean Peninsula large amount of loess has been applied every year because loess is known to be effective in removing red tide organisms. Effects of loess application in ecosystem of underwater near sea shore were investigated with some physical characteristics of loess. Loess used for the red tide reduction consisted of very fine particles, of which size was mostly less than 0.1 mm. Particles of loess blocked light penetration, which is essential for the underwater ecosystem. Loess also pushed pH down by the hydrolysis activities of aluminium and iron It was found that underwater ecosystems where loess was applied near sea shore were devastated. Sea plants such as sea weeds were gone leaving only their roots. Clams and snails were dead under the loess dust blanket. And fishes were not found at all where loess has been sprayed lot long time. It was found that even if loess has some capacity to reduce red tide temporarily, loess application should be slopped to protect underwater ecosystems.

• Journal of Industrial Technology
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• v.29 no.B
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• pp.57-64
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• 2009

This study has analysed actual overbreak, shotcrete rebound and the ratio between the actual quantity of shotcrete to designed shotcrete measured during a NATM tunnel construction. The measured shotcrete rebound was about 7.2% in average which was about half the allowable rebound (15%), showing shotcrete spraying was performed well. Based on the measurement of excavated tunnel shape, average overbreak was about 28.5cm after tunnel excavation by drill and blasting method. This was about 260% of allowable overbreak. In addition, due to the rebound and overbreak actual amount of shotcrete used in the tunnelling work was about 116.5 % of the designed value. According to the field measurement the ratio of actual shotcrete to designed value showed some relation with standard support pattern, but the size of overbreak did not show the correlation with standard support pattern. Hence current design specifications stating the size of overbreak based entirely on standard support pattern should perhaps be reestablished. The insight into the design guideline regarding overbreak and shotcrete.

• Particle and aerosol research
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• v.4 no.2
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• pp.51-67
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• 2008

In this study, we devoted to kinetic measurement of the catalytic oxidation of iron-containing flame soot particles and better understanding the role of catalytic particles on carbon oxidation in particular at low temperature, targeting on autothermal regeneration of diesel particulate filter by diesel exhaust gas. Carbon-based Fe-containing particles generated by spraying ferrocene-doped diesel fuel in an oxy-hydrogen flame are tested and compared with a commercial carbon black powder for thermogravimetric analysis (TGA), secondary ion mass spectrometry (SIMS), Fourier-transform infrared spectroscopy (FTIR), Induced coupled plasma-Atomic emission spectroscopy (ICP-AES), and High-resolution transmission electron microscopy (HR-TEM). As a result, we found that a small amount of the ferrocene addition led to significant reductions in a on-set temperature and an activation energy of the carbon oxidation as well. An oxygenated surface complex forming at the particle surface could be thought as active species that would be readily consumed in particular at low temperature.

• Journal of ILASS-Korea
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• v.9 no.3
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• pp.22-28
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• 2004

This study is concerned about the characteristics of ultrasonic-energy-added W/O type emulsified fuel. The distilled water was mixed with diesel oil by using ultrasonic energy fuel feeding system and then the SMD of sprayed droplets was measured to find out atomization characteristics of emulsified fuel by using the Malvern 2600 system. The capacitance value was measured to verify stability of the same specimen by using the digital LCR meter, EDC1630 additionally. The main results are as follows; 1) The more measuring distance increases between one hole nozzle tip and analyser bearm, the more SMD increases. 2) The more water content increases, the more capacitance value increases depending on the time. Main Parameters of the study are the amount of water content $0{\sim}30%$ by 5% in emulsified fuel, and the measurement distance, $20{\sim}140mm$ by 10mm or 20mm between nozzle tip and analyser beam.