The emission of off-gas streams from used fuel recycling is a concern in nuclear energy usage as they contain radioactive compounds, such as, 3H, 14C, 85Kr, 131I, and 129I that can be harmful to human health and environment. Radioactive iodine, 129I, is particularly troublesome as it has a half-life of more than 15 million years and is prone to accumulate in human thyroid glands. Organic iodides are hazardous even at very low concentrations, and hence the capture of 129I is extremely important. Dynamic adsorption experiments were conducted to determine the efficiency of sodium mordenite, partially exchanged silver mordenite, and fully exchanged silver mordenite for the removal of methyl iodide present at parts per billion concentrations in a simulated off-gas stream. Kinetic analysis of the system was conducted incorporating the effects of diffusion and mass transfer. The possible reaction mechanism is postulated and the order of the reaction and the values of the rate constants were determined from the experimental data. Adsorbent characterization is performed to investigate the nature of the adsorbent before and after iodine loading. This paper will offer a comprehensive understanding of the methyl iodide behavior when in contact with the mordenites.

본 연구는 농촌진흥청 국립원예특작과학원 채소과에서 육성 중인 고추 34계통과 세계채소센터 육성 계통과 자원 12점 등 총 46점의 고추를 공시하여, 종자의 발아율, 수량 및 상품과율, 그리고 화분발아율을 조사하여 내서성이 강한 고추 자원을 선발하기 위하여 수행되었다. 1. 종자발아율 비교에서 여름종자는 가을종자 대비 상대적인 피해율은 4.3~100% 범위였고, H42(1.6%), H16(5.0%), H14(6.3%), H02(12.4%), H44(13.7%), H12(15.9%), H03 (17.6%), H17(23.4%) 순으로 대조 계통인 H37(26.2%)에 비해 피해율이 낮았다. 2. 고추 과실의 수량은 34.4~446.5g, 총 과실수는 2.0~134.3 개를 나타냈다. 상품과 비율에 있어서 75% 이상은 H22(95.0%), H16(89.1%), H37(88.4%), H40(86.4%), H6 (86.0), H27(83.7%), H04(83.6%), H03(82.6%), H08(81.1%), H44(81.4%), H02(80.0%), H45(79.1%), H17(78.7%), H19 (77.7%), H34(77.0%), H15(76.9%), H42(76.3%) 순으로 나타 났다. 3. 고온 처리에 의한 화분발아율의 피해율은 H06(59.5%), H14(74.4%), H44(85.3%), H03(90.2%)가 대조구인 H37 (94.7%)과 나머지 다른 고추에 비해 상대적으로 낮았다. 이상의 결과, 가을종자 대비 여름종자 종자발아율의 피해율, 수량 및 상품과율, 그리고 고온 처리에 의한 화분발아율 등을 고려하여, H03, H04, H06, H14, H17, H22, H44, H45 계 통을 내서성이 높은 자원으로 선발하였다.

Reverse breeding is a new plant breeding strategy based on crossover suppression during meiosis. This brings forth unprecedented possibilities like the almost instantaneous generation of homozygous parents for a chosen heterozygote. As a proof of concept, an Arabidopsis (Columbia-Landsberg) heterozygote was created that carried a RNAi:DMC1 construct stopping crossover formation. Gametes of this heterozygote were grown directly into doubled haploid offspring. These offspring show different combinations of (non-recombinant) Columbia and Landsberg chromosomes. Among these doubled haploids we retrieved the original Columbia parent and a complete set of chromosome substitution lines. From among these we could easily select two so called “complementing DHs” from which the Col-Ler hybrid could be re-created. Essentially, breeders can now bring single choice uncharacterized heterozygotes into a hybrid breeding program by creating parental lines for them. Reverse breeding superficially resembles apomixis (clonal reproduction through seeds) since both allow the preservation of heterozygous genotypes. Reverse breeding, however, has very different uses because it generates homozygous breeding lines. It thus allows for the improvement of the starting heterozygote because new traits can be introgressed into its newly produced parental lines. Reverse breeding is thought to be suitable for crops with smaller chromosome numbers (x ≤ 12). It will be discussed how reverse breeding could be developed for such crops, and it will be shown how reverse breeding presents very interesting new possibilities studying epistasis and heterosis through chromosome substitution lines. Further experiments with reverse breeding lines allow testing of a variety of intriguing breeding questions like to what extent a (heterozygous) genome actually determines a plants phenotype.