Polyacrylonitrile (PAN)-based carbon fibers (CFs) and their composites, CF-reinforced plastics, have garnered significant interest as promising structural materials owing to their excellent properties and lightweight. Therefore, various processing technologies for fabricating these advanced materials using thermal energy have been intensively investigated and developed. In most cases, these thermal energy-based processes (heat treatment) are energy and time consuming due to the inefficient energy transfer from the source to materials. Meanwhile, advanced processing technologies that directly transfer energy to materials, such as radiation processing, have been developed and applied in several industrial sectors since the 1960s. Herein, general aspects of radiation processing and several key parameters for electron-beam (e-beam) processing are introduced, followed by a review of our previous studies pertaining to the preparation of low-cost CFs using specific and textile-grade PAN fibers and improvements in the mechanical and thermal properties of CF-reinforced thermoplastics afforded by e-beam irradiation. Radiation processing using e-beam irradiation is anticipated to be a promising method for fabricating advanced carbon materials and their composites.

A carbon fiber reinforced thermoplastic (CFRTP) was irradiated with a high energy electron-beam. As a result, the tensile strength of high-density polyethylene (HDPE)-based CFRTPs was significantly improved by gradually increasing the electron-beam dose. It was confirmed that the adhesion between CF and HDPE was improved and the surface properties of CF and HDPE were readily modified by electron-beam. It was verified from spectroscopic analysis that various oxygencontaining functional groups were formed on the surface of CF and HDPE by irradiation and we believe that strong attractive interactions took place among these functional groups at the interface of CFs and HDPE. Finally, it was conclusive that electron-beam irradiation provided two main effects on CFRTPs. One was cross-linking of thermoplastic resin for efficient load transfer from resin to CF and the other was formation of surface functional group and attractive interaction of these functional groups at the interface of fiber and matrix. These two effects showed synergetic contribution to enhance the mechanical properties of CFRTP.

In this study, we investigated the growth of striped mullet (Mugil cephalus), Yesso scallop (Patinopecten yessoensis) and kelp (Saccharina japonica) farmed under the IMTA (integrated multi-trophic aquaculture) system developed by national institute of fisheries science (NIFS). The farmed striped mullets grew from an initial length and weight of 152.5±12.1 and 41.6±7.8 g in October 2013 to 154.2±5.6 and 47.5±8.6 g in November, 160.2±8.7 and 55.9±9.1 g in December and 168.4±9.6 and 58.4±8.7 g in January. The fish continued to grow and reached 190.2±9.4 in length and 87.5±8.9 g in weight in April and 256.4±9.7 and 156.7±6.7 g in October 2014. The daily growth rate (DGR) for total fish length was 0.015 0.1 /day during the periods of fast growth and attained 0.038 0.1 /day during February March. The kelp grew from an initial blade length and wet weight of 1.19±0.2 and 0.0028±0.0012 g in January 2014 to 3.3±0.8 and 2.5±0.9 g in February and 126.5±11.6 and 107.4±22.6 g in March, after which, erosion occurred and slowed the growth. The DGRs for kelp length ranged 0.03 1.9 /day in January 2014 and increased to 0.88 1.9 /day during March April. Increasing water temperatures beginning in April lowered the DGR to 0.03 /day. Yesso scallops grew from an initial shell length, shell height and wet weight of 11.83±0.6 , 12.68±0.7 and in September 2013 to 19.9±2.5 , 20.8±2.6 and 0.9±0.04 g in November 2013. They continued to grow to 45.91±0.71 in shell length, 42.55±0.8 in shell height and 12.7±1.3 g in wet weight by May 2014 and 60.2±2.51 , 554.6±2.61 and 24±2.70 g by October 2014. The DGRs for shell length of Yesso scallop ranged from 0.02 to 0.256 /day with higher values of 0.256 0.27 /day during November December 2013 and March April 2014.