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The characteristics and particle numbers of residual microplastics were investigated in ark shell to establish a food safety management method. The ark shell employed herein was purchased in Jeonnam province. The experimental method involved disassembly of the organic matter present in the ark shell using 10% KOH, followed by qualitative and quantitative analysis of the microplastics using Fourier transform infrared (FT-IR) spectroscopy. The mean value of residual microplastics was 0.8 microplastic (MP)/individual in ark shell A, and were found to consist of one polypropylene (PP), two polyethylenes (PE), and one epoxy. The mean value of residual microplastics was 1.2 MP/individual in ark shell B, and were found to consist of two PP, two PE, and two polyesters. In ark shell C, the mean value of residual microplastics was 1.6 MP/individual, consisting of two PP, two PE, two polyesters, and two acrylates. These results indicated that the residual microplastics in the ark shell are present in relatively lower quantitative levels compared to the results presented in previous reports. However, due to the ability of microplastics to contaminate marine life by absorbing harmful chemicals, thereby adversely affecting marine food product safety, regular monitoring of the residual microplastics present in marine products is necessary to ensure food safety.

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This paper presents the design of a water-cooled radio-frequency(RF) load with simple structure, for use in the ultrahigh-frequency (UHF) band. After establishing a formula to obtain the physical properties that affect RF matching, we measure the permittivity and tanδ(Loss tangent) of tap water. Because the temperature of tap water increases upon applying high power, we measure the permittivity and tanδ for all changes in the temperature of tap water. In order to reduce the length of the water-load, molybdate with high tanδ is mixed with tap water. The loss tangent of the mixture is found to be approximately 26 times higher than that of tap water. Finally, we manufacture a water-cooled RF load and measure its characteristics. A reflection coefficient of −19 dB and bandwidth of 15 % is obtained at 460 MHz.