Pyroprocessing is a promising technology for managing spent nuclear fuel. The nuclear material accounting of feed material is a challenging issue in safeguarding pyroprocessing facilities. The input material in pyroprocessing is in a solid-state, unlike the solution state in an input accountability tank used in conventional wet-type reprocessing. To reduce the uncertainty of the input material accounting, a double-stage homogenization process is proposed in considering the process throughput, remote controllability, and remote maintenance of an engineering-scale pyroprocessing facility. This study tests two types of mixing equipment in the proposed double-stage homogenization process using surrogate materials. The expected heterogeneity and accounting uncertainty of Pu are calculated based on the surrogate test results. The heterogeneity of Pu was 0.584% obtained from Pressurized Water Reactor (PWR) spent fuel of 59 WGd/tU when the relative standard deviation of the mass ratio, tested from the surrogate powder, is 1%. The uncertainty of the Pu accounting can be lower than 1% when the uncertainty of the spent fuel mass charged into the first mixers is 2%, and the uncertainty of the first sampling mass is 5%.

Cordyceps militaris, a well-known traditional Chinese medicine, has multiple health-promoting effects. It is used as a herbal remedy and health food in Asian countries. Cultured mycelia are often used as a substitute for natural C. militaris. In the present study, the mycelia and fruiting bodies of artificially cultured C. militaris were analyzed using a metabolomics approach. The protein and crude fat contents of the mycelia were substantially higher than those of the fruiting bodies. The top three abundant amino acids in the mycelia were proline (3.9 g/100 g), aspartic acid (2.9 g/100 g), and glutamic acid (2.7 g/100 g). The carbohydrate content was similar in the fruiting bodies and mycelia. Analysis revealed that both the fruiting bodies and mycelia are rich in phenolic compounds and exhibit antioxidant activity. Further, six metabolites were significantly different between the mycelia and fruiting bodies. The levels of Ca, glucose, Mg, and Se were higher in the mycelia than in the fruiting bodies. In contrast, mannitol and Zn were more abundant in the fruiting bodies. The current study provides a comprehensive metabolic profile of the mycelia and fruiting bodies of artificially cultured C. militaris. Such an exercise is potentially important for understanding the metabolism of C. militaris and facilitating the use of cultured mycelia as a supplement to C. militaris fruiting bodies in traditional Chinese medicine.

The PoN (Proof of Nonce) distributed consensus algorithm basically uses a non-competitive consensus method that can guarantee an equal opportunity for all nodes to participate in the block generation process, and this method was expected to resolve the first trilemma of the blockchain, called the decentralization problem. However, the decentralization performance of the PoN distributed consensus algorithm can be greatly affected by the network transaction transmission delay characteristics of the nodes composing the block chain system. In particular, in the consensus process, differences in network node performance may significantly affect the composition of the congress and committee on a first-come, first-served basis. Therefore, in this paper, we presented a problem by analyzing the decentralization performance of the PoN distributed consensus algorithm, and suggested a fairness control algorithm using a learning-based probabilistic acceptance rule to improve it. In addition, we verified the superiority of the proposed algorithm by conducting a numerical experiment, while considering the block chain systems composed of various heterogeneous characteristic systems with different network transmission delay.

The poor durability issue of polymer electrolyte membrane fuel cells is a major concern in terms of their commercialization. To understand the degradation mechanism of the catalysts, an accelerated durability test (ADT) was conducted according to the protocol established by internationally accredited organizations. However, reversible and irreversible factors contributing to the loss of activity have not yet been practically segregated because of the limitations of a batch-type three-electrode system, leading to the misunderstanding of the deactivation mechanism. In this study, we investigated the effect of a fresh electrolyte on the ADT and recovery process. When the fresh electrolyte was used at every range of the cycle, the chances of incorrect detection of dissolved CO and Pt ions in the electrolyte were very low. When the same electrolyte was used throughout the test, the accumulated Pt ions were deposited on the surface of the Pt nanoparticles or carbon support, affording an increased electrochemical surface area (ECSA) of Pt. Therefore, we believe that periodic replacement by a fresh electrolyte or a continuous-flow electrolyte is essential for the precise determination of the structural and electrochemical changes in Pt/C catalysts.

일상적인 화학제품들의 사용량이 증가함에 따라 사용되었던 염료 폐기물 처리 또한 중요한 환경 적인 문제로 대두되었다. 이러한 염료폐기물은 광촉매를 이용하여 분해시킬 수 있는데, 졸-겔 기술을 활용 하면 매우 비용 효율적으로 광촉매를 합성할 수 있다. 졸-겔 기술은 나노스케일의 막 형성에도 상당히 유 용하며 간단하게 다층구조를 형성할 수도 있다. 본 연구에서는 다양한 염료 분해에 효과가 있는 산화아연 (ZnO) 이용하여 다중 회전도포 방법으로 다층구조(3층, 5층)를 가진 ZnO 막을 형성하였다. 성능비교를 위해 단일 회전도포 방법에 의한 단층구조를 가진 ZnO 막을 대조군으로 준비하였다. X선 회절분석기 및 에너지 분산 X선 분광계를 이용하여 ZnO의 구조 및 원소분석을 수행하였고, 주사전자현미경을 통해 나노 선같은 표면형상을 관찰할 수 있었다. 추가적으로 UV-Vis 분광광도계를 활용하여 자외선의 흡수도를 측정 하였다. 5층구조를 가진 ZnO 막이 단층 구조를 가진 ZnO 막에 비해 모의 메틸렌 블루를 49% 더 많이 분해하였다. 결론적으로, 다층구조를 가진 ZnO 는 메틸렌블루 염료를 더욱 효과적으로 분해하는 광촉매로 써 유용하다는 알 수 있었다.

The Mn-Zn ferrite powders were prepared by high energy ball milling, then compacted and sintered at various temperatures to assess their sintering behavior and magnetic properties. The initial ferrite powders were spherical in shape with the size of approximately 70 m. After 3 h of ball milling at 300 rpm, aggregated powders ~230 nm in size and composed of ~15 nm nanoparticles were formed. The milled powders had a density of ~70 % when compacted at 490 MPa for 3 min. In the samples subsequently sintered at 1,273 K ~ 1,673 K for 3 h, the MnZnFe2O4 phase was detected. The density of the sintered samples had a tendency to increase with increasing sintering temperature up to 1,473 K, which produced the highest density of 98 %. On the other hand, the sample sintered at 1,373 K had the highest micro-hardness of approximately 610 Hv, which is due to much finer grains.

We conducted diagnostic investigations to analyze the causes of abortions (46 cases, 65.7%), deaths (22 cases, 31.4%) and muscular lesions (2 cases, 2.9%) occurred after foot and mouth disease (FMD) vaccination in livestock farms in Korea. Bacterial culture, enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) were performed to detect the causative agents of abortion in bovine and caprine. The diagnostic results showed that 36 (51.4%) cases, referring as “Identified”, were occurred by influence of underlying disease including bovine viral diarrhea (12 cases, 17.1%), neosporosis (7 cases, 10.0%), septicemic colibacillosis (5 cases, 7.1%), Q fever (4 cases, 5.7%) and other abnormal conditions (8 cases, 11.4%) not by vaccination. Other 2 (3.0%) cases were suspected to be vaccine-associated adverse reaction on the basis of pathological findings (shock lung, oil-component-induced granuloma) and clinical symptoms (dyspnea with pulmonary edema). The other 32 (45.7%) cases were determined “Unknown” because any pathogens and pathological changes were not identified. However, many of the “Unknown” cases were presumptive to be the vaccine-related adverse reaction based on epidemiological investigation, especially, the cases which showed the clinical signs within 2 days after the vaccination. It is important to conduct pathological, microbilogical and epidemiological investigation to diagnose whether the cases are from vaccine-associated adverse reaction or not.

본 연구는 거베라 주산지인 경북과 경남 지역의 농가 재배 및 스마트팜 현황을 조사하고 분석하고자 수행하였다. 조사방법은 2020년 81 농가를 대상으로 대면 설문조사를 실시하였다. 거베라 경영주 연령은 50∼60대가 71.6%로 가장 많았고, 30∼ 40대가 16%, 70세 이상이 9.9%, 30세 이하는 2.5% 순이었다. 거베라 재배 경력은 5년 이하가 37%였으며, 6∼10년 25.9%, 11∼20년 29.6%, 21년 이상 농가가 7.4%였다. 재배 면적은 0.3 ∼0.6ha가 61.7%로 가장 많았고, 0.3ha 미만이 30.9%, 0.6ha 이상이 7.4%였으며, 전체 평균재배 면적은 0.37ha였다. 거베라 재배 농가당 평균 인력은 자가 노동력 2.1명, 고용 노동력 0.8명 이었다. 재배 방식에서 토경 88.9%, 양액재배 농가는 11.1%였다. 국산품종을 전체 또는 일부라도 재배하고 있는 농가는 61.7%였고 외국산 거베라 품종만 재배하고 있는 농가는 38.3% 였다. 거베라 병해충 발생조사에서 병 발생이 많았다고 응답한 농가는 91.4%였으며, 충 발생이 많았다고 응답한 농가는 98.8% 였다. 스마트팜 시스템을 설치한 농가는 12.3%였으며, 설치하지 않은 농가에서 향후 설치할 의향이 있다고 응답한 농가는 76.9% 였다. 향후 경영계획을 묻는 질문에서 현상유지 80.2%, 축소 8.6%, 경영확대 11.1%였으며, 경영 확대를 대답한 농가는 경북 지역이 8농가로 경남지역 1농가 보다 많았다.