The decommissioning of nuclear facilities produces various types of radiologically contaminated waste. In addition, dismantlement activities, including cutting, packing, and clean-up at the facility site, result in secondary radioactive waste such as filters, resin, plastic, and clothing. Determining of the radionuclide content of this waste is an important step for the determination of a suitable management strategy including classification and disposal. In this work, we radiochemically characterized the radionuclide activities of filters used during the decommissioning of Korea Research Reactors (KRRs) 1 and 2. The results indicate that the filter samples contained mainly 3H (500–3,600 Bq·g−1), 14C (7.5–29 Bq·g−1), 55Fe (1.1– 7.1 Bq·g−1), 59Ni (0.60–1.0 Bq·g−1), 60Co (0.74–70 Bq·g−1), 63Ni (0.60–94 Bq·g−1), 90Sr (0.25–5.0 Bq·g−1), 137Cs (0.64–8.7 Bq·g−1), and 152Eu (0.19–2.9) Bq·g−1. In addition, the gross alpha radioactivity of the samples was measured to be between 0.32–1.1 Bq·g−1. The radionuclide concentrations were below the concentration limit stated in the low- and intermediatelevel waste acceptance criteria of the Nuclear Safety and Security Commission, and used for the disposal of the KRRs waste drums to a repository site.

Upgraded activated carbons (ACs) are typically synthesized by mixed methods, such as solid–solid mixing and wet impregnation of low-grade ACs with KOH. This study compares the properties of upgraded ACs prepared by different methods using elemental analysis, X-ray photoelectron spectroscopy, N2 adsorption isotherms, and X-ray diffraction. In ACs produced by the solid–solid mixing, the ratio of potassium activator is proportional to the surface area and amount of gas produced. However, in wet impregnated ACs, the potassium ratio exhibits a zero or negative correlation. It is demonstrated that potassium ions in solution are not transferred to K2O and do not contribute to the surface area and pore size, generating less amount and different composition of gases. As such, impregnated ACs exhibit similar surface areas and large pores, regardless of the potassium ratio. The physical properties, such as specific surface areas and pore size distribution, of ACs using wet impregnation were similar to the ACs generated by the water physical activation. It indicated that the KOH does not efficiently act as a chemical activator in the wet impregnation method. Therefore, a certain amount and suitable mixing method of chemical activator play an important role in the property upgrade of ACs.

The properties of powder metallurgy products are related to their densities. In the present work, we demonstrate a method to apply artificial neural networks (ANNs) trained on experimental data to predict the bulk density of barium titanates. The density is modeled as a function of pressure, press rate, heating rate, sintering temperature, and soaking time using the ANN method. The model predictions with the training and testing data result in a high coefficient of correlation (R2 = 0.95 and Pearson’s r = 0.97) and low average error. Moreover, a graphical user interface for the model is developed on the basis of the transformed weights of the optimally trained model. It facilitates the prediction of an infinite combination of process parameters with reasonable accuracy. Sensitivity analysis performed on the ANN model aids the identification of the impact of process parameters on the density of barium titanates.

2018년 현재까지 농림축산검역본부 호남지역본부로 수입된 식물은 220종 17,030건으로 우드펠렛(18%), 주정박(8%), 페스큐 건초(8%), 알파파건초(8%), 귀리건초(6%), 혼합건초(5%), 티모시건초(5%), 라이그래스건초(5%), 목화씨(사료용)(4%), 소나무원목(3%) 등의 순이다. 이와 같이 호남지역은 비재식 사료류(건초 등) 수입비중이 높으며 이는 전국 수입 건수의 약 67%에 달한다. 검역해충은 795건 검출되었으며 이 중 관리해충 294건, 잠정규제해충 146건, 비검역해충 307건 등이다. 관리해충 중 Carpophilus obsoletus가 210건(72%), 잠정규제해충 중 Cryptoletes ferrugineus가 56건(39%)으로 높은 검출율을 보였다. 또한 호남지역으로 수입 된 재식용 구근류는 생강 및 생강구근, 마늘구근이며 전국 수입 건수의 약 42%를 차지한다. 수입 된 생강 및 생강구근 91건 중 37건에서 해충(선충)을 발견하였고 Meloidogyne sp.(잠정규제해충) 검출로 9건이 폐기·반송되었다. 수입된 마늘구근 34건 중 29건에서 해충을 발견하였고 Carpophilus obsoletus(관리해충) 18건, Cryptoletes ferrugineus(잠정규제해충) 11건이 검출되어 소독하였다.

Harmonia axyridis have become extremely popular through their extensive elytra and spot variation for many years. However, phenotypic polymorphism and striking visual phenotypes are not yet to be extensively studied. With growing attention to polymorphism of H. axyridis, it is imperative to study involved in genomic research in order to elucidate the molecular mechanisms underlying the diversity of elytra variation. To figure out suitable approach for analyzing genes of H. axyidis, we assessed RNAi as a tool for functional analysis. In order to demonstrate the utility of RNAi technique on H. axyridis, we conducted cDNA library screening to affirm silencing effect. We choose random genes from cDNA clones and the random genes were synthesized into dsRNA. After the injection of dsRNA into last instar larvae, we observed morphological defects or deaths. To investigate the effectiveness of knockdown in H. axyridis, we performed quantitative real time PCR on H. axyridis that appears the most distinctive features. These results provide that RNAi is highly applicable in H. axyridis and it will be useful for the gene functional analysis.

지난 18년간(2000~2018년 3월) 검역현장에서 검출된 해충의 종류는 1,980종이다. 이중 딱정벌레목은 전체의 42.6% (곤충은 1,707종으로 86.2%)로 검역적으로 매우 중요하며, 여기에서 가는납작벌레과(Silvanidae)는 딱정벌레목 머리대 장상과에 포함되고, 이들의 검출 종은 21종, 횟수는 15,516회로 가장 많은 비율을 차지한다. 최근 18년간 검출률 결과 Ahasverus sdvana(쌀머리대장)로 6,404회로 가장 많이 검출되었으며, Slivanus didentatus(두니가는납작벌레)는 6,225회, Oryzaephilus surinamensis(머리대장가는납작벌레)는 1,123회, Oryzaephilus mercator(곡물가는납작벌레)는 415 회의 검출률을 보여준다. 가는납작벌레과는 딱정벌레목중 가장많은 검출률을 보이는 과로 검역현장에서 매우 중요한 과에 속한다. 본 연구는 검역과정에서 검출되는 가는납작벌레과 곤충 중 검역현장에서 최초로 발견된 Monanus 속의 한 종을 발견하여 보고 한다.