KORAD (Korea Radioactive Waste Agency, http://www.korad.or.kr) has stored slightly contaminated ascon (asphalt coated concrete mixture) that was introduced to Gyeongju repository about a decade ago waiting for a final disposal. It is believed to be mainly contaminated by radioisotope 137Cs due to impurities introduced from the outside during the ascon manufacturing process. We studied characteristics of the radioactive waste to see whether this material would be proper enough to be disposed in Gyeongju LILW repository or be other ways to reduce the disposal volume including self-disposal before its final disposal otherwise. KORAD looked into the properness of characteristics of ascon in terms of WAC (Waste Acceptance Criteria) documented by KORAD that includes general chemical and physical properties of asphalt, density, size of grains, content of organic material and possibility of existence of chelate materials that qualitatively limited to be disposed by the criteria. And other associated characteristics such as gas generation and bio degradation were also investigated. Based on the data obtained from the study, we proposed various plausible solutions in associated with operational and disposal safety and economic view points. This study will be used for KORAD’s decision on how to control and safely dispose the spent ascon within a reasonable time period. And also those experiences may be applied for other LILW issues that require treatment or conditioning of radioactive wastes in the future.

To investigate the effect of the catalyst and metal–support interaction on the methane decomposition behavior and physical properties of the produced carbon, catalytic decomposition of methane (CDM) was studied using Ni/SiO2 catalysts with different metal–support interactions (synthesized based on the presence or absence of urea). During catalyst synthesis, the addition of urea led to uniform and stable precipitation of the Ni metal precursor on the SiO2 support to produce Ni-phyllosilicates that enhanced the metal–support interaction. The resulting catalyst upon reduction showed the formation of uniform Ni0 particles (< 10 nm) that were smaller than those of a catalyst prepared using a conventional impregnation method (~ 80 nm). The growth mechanisms of methane-decomposition-derived carbon nanotubes was base growth or tip growth according to the metal–support interaction of the catalysts synthesized with and without urea, respectively. As a result, the catalyst with Ni-phyllosilicates resulting from the addition of urea induced highly dispersed and strongly interacting Ni0 active sites and produced carbon nanotubes with a small and uniform diameter via the base-growth mechanism. Considering the results, such a Ni-phyllosilicate-based catalyst are expected to be suitable for industrial base grown carbon nanotube production and application since as-synthesized carbon nanotubes can be easily harvested and the catalyst can be regenerated without being consumed during carbon nanotube extraction process.

Sustainable capacity building of the rice value chain in Africa is essential in achieving the rice self-sufficiency and poverty alleviation. The breeding capacity enhancement has also been at the heart of AfricaRice’s mandate. Therefore, the Korea-Africa Food and Agriculture Cooperation Initiative (KAFACI) has concentrated breeding capacity enhancement for young breeders or breeding technicians of national research institutes in the KAFACI member countries. Four-month trainings have been conducted at the Regional Training Center located in Saint Louis, Senegal. The actual practice training is as follows; First is to learn practical skills and techniques of key aspects of rice breeding which are field preparation and layout, sowing, transplanting, fertilizer application, weed control, water management, hybridization/crossing, selection, yield and yield components determination, and rice palatability testing. Second is to learn some theoretical aspects of plant breeding through lectures including basic principles of breeding, evaluation for biotic and abiotic stresses, and statistical analysis. Third is to learn about the accurate use of field and lab equipment for rice breeding. Forth is to learn about proper scientific reporting and presentation. The courses were organized twice per year following two rice cultivation seasons in Senegal. From 2019, a total of 24 trainees participated in the 4 month courses. We believe they have acquired the basic knowledge and skills to implement rice breeding activities indpendently in their countries.

The Korea-Africa Food and Agriculture Cooperation Initiative (KAFACI) has been cooperating with AfricaRice since 2014 for the eradication of hunger and poverty in Africa through sustainable agriculture and its industrialization. At first, rice breeding activities for staple food production started with KAFACI member countries by sharing high-yielding Tongil-type rice breeding lines and varieties. The Africa Rice Development Partnership project entitled “Enhancement of high-yielding rice germplasm and breeding capacity of rice producing countries in Africa” is implemented for the period from 2016 to 2025 with three phases. The actual rice breeding activities have been conducted by applying anther culture haploid breeding technology in the laboratory and field of AfricaRice Saint-Louis center. The 1,547 elite lines selected through participatory variety selection were distributed to 21 national breeders of KAFACI member countries. These lines derived from the 1,181 cross combination and 34,616 breeding lines on Korea and AfricaRice germplasm crossed. Among them 11 new Tongil-type rice varieties have been selected and registered in the national variety catalogue of Senegal, Mali, Rwanda, Malawi, and Tanzania.

The consumption of pre-treated vegetables (including fresh-cut vegetables) has been significantly increased because of their ease of use for cooking. Vegetable cutting machine has been widely utilized for producing fresh-cut vegetables or agricultural products with different sizes; however, its design standard is not specifically established depending on types of agricultural products. Therefore, this study was conducted to determine mechanical properties (compressive and shear force) of targeted agricultural products (radish, carrot, squash, cucumber, shiitake mushroom and sweet potato) for developing multipurpose vegetable cutting machine. According to ASAE standard (s368.3), compressive and shear force of targeted agricultural products were measured by using custom built UTM (universal testing machine). Shape type of samples and speed ranges (5~15 mm/min) of loading rate on bioyield and shear points were varied by targeted agricultural products. The range of averaged bioyield points of targeted agricultural products were between 7.89 and 146.98 N. On the other hands, their averaged shear points were from 22.50 to 53.47 N. Results clearly showed that the bioyield and shear points of targeted agricultural products were thoroughly affected by their components. As accumulating compressive and shear points of agricultural products, it can be technical feasible to establish the design standard and control mechanism of multipurpose vegetable cutting machine.

The Riptortus-Burkholderia symbiosis is a newly emerging insect-bacterium symbiotic system. This symbiosis system has a good merit as an experimental model system to produce the non-symbiotic (apo) and symbiotic (sym) host insect. In recent reported papers, the symbionts play important biological roles for the host insects. Meanwhile, juvenile hormone (JH) is one of major hormone synthesized corpora allata(CA) to control many physiology of insect. However, the study for cross-talk mechanism between symbionts and host hormones to control important physiological phenomenon of insects is almost none. In this study, we found that Riptortus speed up adult emerging and increase egg laying on presence of symbiont Burkholderia. Also we found that hexamerin proteins, which were controlled the expression by JH, were accumulated in sym-Riptortus hemolymph compare with apo-Riptortus. According as combined results, we hypothesized that the gut symbiont Burkholderia can control JH titer to conclude out beneficial effects such as development and reproduction of R. pedestris. To verify this hypothesis, we examined measurement of JH titer, expression of hexamerins as JH response genes and RNAi for hexamerin protein during whole Riptortus life on presence or absence of symbiont Burkholderia. All results demonstrated that gut symbiont controlled JH titer of Riptortus. Controlled JH amount by symbiont Burkholderia in host midgut regulated hexamerin protein expression for speeding up adult emerging and increasing egg production.