• Nuclear Engineering and Technology
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• 제56권1호
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• pp.106-113
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• 2024

Understanding the tritium release and retention behavior of candidate tritium breeder materials is crucial for breeder blanket design. Recently, a melt spraying process was developed to prepare Li₄SiO₄ pebbles, which were subsequently subjected to the in-pile tritium production and extraction platform in China Mianyang Research Reactor (CMRR) to investigate their in-situ tritium release behavior and irradiation performance. The results demonstrate that HT is the main tritium release form, and adding hydrogen to the purge gas reduces tritium retention while increasing the HT percent in the purge gas. Post-irradiation experiments reveal that the irradiated pebbles darken in color and their grains swell, but the mechanical properties remain largely unchanged. It is concluded that the tritium residence time of Li₄SiO₄ made by melt spraying method at 467 ℃ is approximately 23.34 h. High-density Li₄SiO₄ pebbles exhibit tritium release at relatively low temperatures (<600 ℃) that is mainly controlled by bulk diffusion. The diffusion coefficient at 525 ℃ and 550 ℃ is 1.19 × 10^-11 cm²/s and 5.34 × 10^-11 cm²/s, respectively, with corresponding tritium residence times of 21.3 hours and 4.7 hours.

• Korean Journal of Poultry Science
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• 제45권3호
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• pp.193-200
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• 2018

The purpose of this study was to evaluate the influence and safety of spraying Farm Clean-S (FC-S) containing 70% Chamaecyparis obtusa essential oil on the elimination of red mite in laying hens. In total, 300 laying hens (ISA brown) aged 72 weeks and infected with red mite were assigned to individual cages for five treatments with five replicates for 18 days. Treatments consisted of distilled water (negative control; NC), commercial spray product (positive control; PC), FC-S 0 (original concentration), FC-S 50 (50 times diluted) and FC-S 100 (100 times diluted). The number of red mites, egg production and weight of each group were evaluated daily throughout the whole experimental period. Egg quality and blood biochemical parameters were measured at the end of the experiment. Safety tests were confirmed by feed intake, respiration, lethargy, diarrhea and mortality symptoms after the feeding trial. As the result, more than 80% of red mites were eliminated by the FC-S 0 spray treatment, and FC-S 50 also showed a higher elimination percentage than did PC (P<0.01). However, the elimination effect of the FC-S 100 spray was lower than that of the PC, but higher than that of the NC (P<0.01). These results confirmed that the optimum FC-S dilution rate ranged from 0~50 times with distilled water to eliminate the red mite effectively. The performance, egg quality, blood parameter and safety tests were not significantly different among treatments. Thus, FC-S 0 and FC-S 50 spray treatments can effectively and sustainably control red mite infestations without detrimental effects on the performance, egg quality and plasma biochemical properties of laying hens.

• Applied Chemistry for Engineering
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• 제32권4호
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• pp.409-416
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• 2021

Dimensionally stable electrodes are one of the important components in electrochemical water treatment processes. In the manufacturing of the dimensionally stable electrodes, the type of metal catalyst coated on the surface of the metal substrate, the coating and sintering methods substantially influence their performance and durability. In this study, using Ir-Ru-Ta ternary metal coating, various electrodes were prepared depending on the coating method under the same pre-treatment and sintering conditions, and its performance and durability were studied. As a coating method, brush and spray coating were used. As a result, the reduction in the amount of catalyst ink was achieved because more amount of metal could be coated for the electrode using spraying with the same amount of catalyst ink. In addition, the spray_2.0_3.0 electrode prepared by a specific spray coating method shows the phenomenon of cracking and the uniform coating of the ternary metal on the surface of the coating layer, and results in a high electrochemically active specific surface area, and the decomposition performance of 4-chlorophenol was superior to the other electrodes. However, it was found that there was no significant difference in durability depending on the coating method.

• Steel and Composite Structures
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• 제21권2호
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• pp.429-442
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• 2016

The aim of this paper is to determine temperature and stress distributions in a ceramic based on Partially Stabilized Zirconia coated steel piston crown by using plasma spraying for improving performance of a marine diesel engine. Effects of coating constituent and thickness on temperature and stress distributions were investigated including comparisons with results from an uncoated piston by means of finite element method namely ANSYS. Temperature developed at the coated surface is significantly higher than that of the uncoated piston. The maximum stress components occur between bond coat and adjacent ceramic layer. Provided that coating thickness is constant as 0.5 mm, when numbers of layers increase, magnitude of the normal stress decrease about 34.1% on the base metal surface according to uncoated piston, but the base metal surface temperature of the steel piston increase about 13.1%.

• Journal of the Korean Society of Costume
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• 제56권4호
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• pp.96-107
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• 2006

This survey was performed to gain basic information for the development of new protective clothing of high acceptability in pesticide splaying among small size farmers. The rate of protective clothing wearing was low during pesticide spray although they understand its necessity. The reason for this low acceptability was related to the heat stress and reduced work efficiency deriving from wearing protective clothing. Instead of wearing they tend to carry out spray work while the ambient temperature is not to high. In the similar context, they rather intend to spray in consideration of weather condition instead of wearing protective clothing in the future. However, they are willing to purchase protective clothing if desirable products are developed: the clothing need to be efficient in both protection and work performance; the fanciness in design is not a requisite. This survey result will provide information necessary for the direction of new protective clothing development.

• Transactions of the Korean Society of Automotive Engineers
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• 제21권6호
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• pp.108-116
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• 2013

Diesel engine injector is used for spraying the fuel into the cylinder chamber. Complex phenomenon like cavitation occurs from small scale domain, highly pressurized condition and rapid injection. Flow inside the nozzle affects the whole engine performance including combustion and exhaust, therefore understanding the flow inside the injector nozzle is very important. In this paper, cylindrical and convergent-divergent nozzles are suggested for nozzle types and their influences on nozzle internal flow and nozzle outlet characteristics will be analyzed by changing their outlet diameters.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.305-308
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• 2006

This paper is to investigate the strength, impact endurance and shrinkage of wet spraying type fiber composite mortar for repair material depending on fiber type and product kinds. Fiber composite mortar containing PVA fiber had the highest strength compared to that using any other fiber. Especially, The use of PVA fiber results in a remarkable enhancement in impact strength and an improved volumetric stability. Accordingly, it is confirmed that fiber composite mortar containing PVA fiber has remarkable performance as repair material of damaged section of concrete.

• Journal of the Korean Society for Precision Engineering
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• 제29권3호
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• pp.295-301
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• 2012

The method for spraying of liquids through an electrical field has become a printing method since it can make very small droplet. For electro-hydrodynamic jet printing to become a reliable jetting tool, the jetting performance should be characterized with respect to various jetting conditions. To optimize jetting conditions, the jetting behavior should be measured. In this study, we present a visualization techniques to measure jetting behavior from electro-hydrodynamic (EHD) inkjet head. Unlike most previous method, we use the CCD camera to measure the jetting behavior. For this purpose, LED light is synchronized with jetting signal and sequential image was obtained by adjusting the delay time of the LED light. Finally, merits and demerits of using CCD camera were discussed to measure jetting image from EHD inkjet head.

• Journal of Biosystems Engineering
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• 제23권2호
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• pp.115-124
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• 1998

Over- and under-application of pesticides to crops have recently become main concerns regarding the environment conservation, product cost and firmer's safety. Thus, a uniform and optimal application method of pesticides was needed. The objective of study was to evaluate flow compensating characteristics of a variable flow control system for a boom sprayer using a laboratory setup. At the most variable conditions, the control system was acceptable with the flowrate control strategy. However, the sprayer control system became unstably fluctuating at the long execution time with small tolerance because of the constant valve on-time. This problem was solved by employing a variable on-time control. The optimal values for the damping ratio and the execution time were 2 and 1.0 sec, respectively, with the tolerances less than 3%. The performance of the control system at the optimal conditions were the response time of 3.8sec and the absolute steady-state error of 0.5% with the stable RCV and ROS ( < 1.0).

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.448-457
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• 1996

Chemical application is one of the most important field operation in rice production . Rolling of a boom due to local unevenness and softness in fields causes a local under/over-application of spray. This study was conducted to develop a control system for balancing a boom. A boom mounting mechanism was modfied and a control algorithm was developed in the study. The results for testing the performance of the control system showed that the system could balance the boom in flat and inclined fields. This research can contribute to improve spraying uniformity in applying agricultural chemicals with a boom sprayers.