• Corrosion Science and Technology
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• v.6 no.5
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• pp.261-268
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• 2007

Embedded sensors were used as an in-situcorrosion-sensing device for aircraft and vehicular structures protected by organic coatings. Results are presented changes associated with a standard Airforce aircraft coating and a standard Army vehicle coating were monitored by embedded sensors. These coatings consisted of a polyurethane topcoat and an epoxy primer, however are formulated to provide different characteristics. The ac-dc-ac testing method was used to accelerate the degradation of these coatings while being immersed in a NaCl medium. Electrochemical impedance spectroscopy and electrochemical noise measurement experiments were used to monitor the induced changes. A comparison of the results between coatings subjected to the ac-dc-ac exposure and coatings subjected to only constant immersion in the NaCl medium is presented. The results were used to demonstrate the effectiveness of the ac-dc-ac method at accelerating the degradation of an organic coating without observably changing the normal mechanism of degradation. The data highlights the different features of the coating systems and tracks them while the coating is being degraded. The aircraft coating was characterized by a high-resistant topcoat that can mask corrosion/primer degradation at the primer/substrate interface whereas the vehicle coating was characterized by a low-resistant topcoat with an effective corrosion inhibiting primer. Details of the ac-dc-ac degradation were evaluated by using an equivalent circuit to help interpret the electrochemical impedance data.

• Journal of Surface Science and Engineering
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• v.56 no.4
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• pp.283-287
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• 2023

The structures for road safety are guard rails that protect the cars and passengers. If an accident occurs on the roads after a long period of installation, it may escalate into a major disaster. In order to repair many guard rails, the existing repair method of replacing them with new ones requires enormous financial resources. To solve this problem, the G-SAVE method was developed to repair the guard rail without replacing them. This method removes the rust on the surface of the guard rail and then performs ambient-dip galvanizing coating on it without replacing the new ones. No studies or reports have yet been made on the risk assessment of harmful substances, vehicles for these entire processes. Therefore, this paper focuses on risk assessment using the PHA (Preliminary Hazard Analysis) technique and conducts risk assessment for concept design stage of the coating vehicles.

• Journal of the Korea Safety Management & Science
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• v.25 no.3
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• pp.73-81
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• 2023

This study uses FMECA (Failure Modes, Effects, and Criticality Analysis) and HAZOP (Hazard and Operability), which are widely applied in industrial areas, among risk assessment methods, and applies them to the same system. While FMECA evaluates system failure conditions and analyzes risks, HAZOP evaluates the system comprehensively by evaluating operational risks that may occur based on system parameters. According to data released by the Ministry of Land, Infrastructure and Transport, as of December 2021, the length of roads in Korea is 113,405 km, and the repair of guardrails that have expired must be fixed urgently in terms of traffic safety. Replacing all of these guardrails with new ones requires a very large cost, but if the guardrails are repaired with a vehicle equipped with the G-Save method, carbon emissions are reduced, the repair period is shortened, and great economic benefits can be obtained. However, risk assessment for guardrail coating vehicles has not been done so far. Focusing on this point, this study aims to evaluate the risk of these coating vehicles and describe the results. Finally, we found that the Risk Priority Numbers(RPN) in the FMECA risk assessment were greatly reduced, and 6 risk factors from HAZOP risk assessment and actions were taken.

• Design & Manufacturing
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• v.18 no.3
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• pp.15-21
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• 2024

This study investigates the causes of wrinkle defects in PA12-insulated busbars used in electric vehicles and proposes an improvement method to address these issues. Busbars, essential components for efficient current transmission in electric vehicle battery modules, require complex three-dimensional bending to optimize internal layouts. For this study, oxygen-free copper busbars with a 0.8 mm PA12 insulation coating were subjected to three types of bending tests: flat bending, edge bending, and torsional bending. Experimental results showed that wrinkle defects only occurred during edge bending, while flat and torsional bending modes exhibited no significant issues. Cross-sectional analysis revealed that the PA12 insulation layer's thickness was uneven, with thinner sections on flat areas and thicker accumulation at the comers. This uneven distribution led to poor adhesion between the insulation and copper layers, resulting in the formation of wrinkles, particularly in areas with air gaps ranging from 75 to 250 ㎛. To further analyze the issue, finite element analysis (FEA) of the bending process was performed under adhesive and non-adhesive conditions. The results confirmed that wrinkles formed when the adhesion between the copper and PA12 coating was insufficient. Improved adhesion conditions, achieved through a heat treatment process at 120℃ for 2 hours, significantly reduced the occurrence of wrinkles during edge bending. This study demonstrates that optimizing the adhesion between the insulation coating and the copper busbar, through controlled heat treatment, can prevent wrinkle defects. The findings provide a pathway for enhancing the durability and performance of insulated busbars in electric vehicle applications.

• Journal of Environmental Science International
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• v.30 no.3
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• pp.219-234
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• 2021

Industrial emissions, mainly from industrial complexes, are important sources of ambient Volatile Organic Compounds (VOCs). Identification of the significant VOC sources from industrial complexes has practical significance for emission reduction. VOC samples were collected from July 2019 to June 2020. A Positive Matrix Factorization (PMF) receptor model was used to evaluate the VOC sources in the area. Four sources were identified by PMF analysis, including coating-1, coating-2, printing, and vehicle exhaust. The coating-1 source was revealed to have the highest contribution (41.5%), followed by coating-2 (23.9%), printing (23.1%), and vehicle exhaust (11.6%). The source showing the highest contribution was coating emissions, originating from the northwest to southwest of the sample site. It also relates to facilities that produce auto parts. The major components of VOC emissions from the coating facilities were toluene, m,p-xylene, ethylbenzene, o-xylene, and butyl acetate. Industrial emissions should be the top priority to meet the relevant control criteria, followed by vehicular emissions. This study provides a strategy for VOC source apportionment from an industrial complex, which is helpful in the development of targeted control strategies.

• Journal of the Korean Wood Science and Technology
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• v.35 no.1
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• pp.44-50
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• 2007

The objective of this study was to investigate the influence of the vehicle resin on the coating performance of Dan-Chung. The starch glue (F), fish glue (G), and aqueous acrylic resin emulsion (E) were used as vehicle resins. Panels coated with Dan-Chung were tested at accelerated weathering and outdoor conditions. Aqueous acrylic resin was proved as an excellent vehicle resin for Dan-Chung, because there was no flaking in Dan-Chung film after accelerated weathering and outdoor exposure. Discoloration of Dan-Chung using E was the smallest among the acceleratedly weathered panels. Adhesive property of Dan-Chung film using G was. remarkably improved by G-undercoating. On the contrary, G-undercoating lowered adhesive property of Dan-Chung film using E.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.585-591
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• 2013

A robot automation system for coating uniformly a big radiator used in PPS(Packaged Power Station), which consists of 6-axis robot with spray gun, travelling vehicle, supply device of coating paint and thinner with pressured air, HMI controller and robot path OLP(Off-Line Programming), was developed. Experimental results on an optimum operation condition show that a coating thickness is $43{\mu}m$, which is satisfied to a design reference of $25-100{\mu}m$. A productivity of the developed coating robot automation system based on OLP is about 12.6 times of that of manual operation.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.13-16
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• 2002

$SrZrO_3 $resistive oxide barriers on Ag sheathed Bi2223 tapes were prepared by the sol-gel and dip coating method to reduce AC coupling loss. The performance of the dip-coated $SrZrO_3 $ thin films was evaluated in terms of bond strength by varying the Sr/Zr mol ratio and the amount of organic vehicle (ethyl cellulose and a-terpineol) additives. The bond strength of the coatings increased as the Sr/Zr ratio decreased and the amount of organic vehicle rose, respectively. It was found that the effect of organic vehicle addition was more pronounced, suggesting that the adherence of the $SrZrO_3 $ films on Bi2223 tapes was governed primarily by the amount of organic vehicle additive.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.4_2
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• pp.591-598
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• 2023

In this study, the corrosion resistance by salt spray was evaluated using A6061-T6 for an electric vehicle battery pack case coated with an organic/inorganic hybrid solution. The lowest curing temperature of 190 ℃ resulted in significant corrosion and pitting. Meanwhile, no corrosion was observed in the coated specimens at 210 ℃ and 230 ℃ except at 210 ℃ - 6 min and 8 min. The surface of the as-received coating specimen observed by FE-SEM exhibited streaks and dents in the rolling direction, but the coating surface was clean. On the 190 ℃ - 6 min coating specimen, which had a lot of corrosion, rolling streaks spread, and dents were caused by corrosion. The 200 ℃ - 12 min coating specimen did not show corrosion, but it showed an etched surface. In the line profile, Si, the main component of the coating solution, was detected the most, and Ti was also detected. In the coating specimens with salt spray, O increased and Si decreased, regardless of corrosion. The peeling rate by adhesion evaluation was 26 - 87% for the 190 ℃ coating specimen, 4 - 83% for the 210 ℃ coating specimen, and 94 - 100% for the 230 ℃ coating specimen. The optimal curing conditions for the coating solution used in this study were 210 ℃ for 10 min.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.389-396
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• 2017

Restorations of automotive parts have been done ever since the first vehicle was produced. Because the most expensive parts of a vehicle are in the engine system, there have been various restoration methods developed for engine parts. In the case of commercial diesel engines, the fuel injection device is a key and expensive component. It also has a significant effect on vehicle performance. In particular, reduced engine power and increased exhaust gas emissions may result from mechanical damage due to abrasion of the spill valve in the fuel injection system of a diesel engine. In this paper, restoration techniques for damaged parts are applied to restore the abrasion of a spill valve of fuel injection, also called as the "unit injector", of commercial diesel engines. In order to recover the damage, optimized polishing techniques using hard-metal and coating processes are applied. To evaluate restoration techniques for the spill valve, performance and durability tests are performed on a test bench.