In this study, an aerosol process was introduced to produce CaCO3. The possibility of producing CaCO3 by the aerosol process was evaluated. The characteristics of CaCO3 prepared by the aerosol process were also evaluated. In the CaCO3 prepared in this study, as the heat treatment proceeded, the calcite phase disappeared. The portlandite phase and the lime phase were formed by the heat treatment. Even if the CO2 component is removed from the calcite phase, there is a possibility that the converted CO2 component could be adsorbed into the Ca component to form a calcite phase again. Therefore, in order to remove the calcite phase, carbon components should be removed first. The lime phase was formed when CO2 was removed from the calcite phase, while the portlandite phase was formed by the introducing of H2O to the lime phase. Therefore, the order in which each phase formed could be in the order of calcite, lime, and portlandite. The reason for the simultaneous presence of the portlandite phase and the lime phase is that the hydroxyl group (OH−) introduced by H2O was not removed completely due to low temperature and/or insufficient heating time. When the sufficient temperature (900°C) and heating time (60 min) were applied, the hydroxyl group (OH−) was removed to transform into lime phase. Since the precursor contained the hydrogen component, it could be possible that the moisture (H2O) and/or the hydroxyl group (OH−) were introduced during the heat treatment process.

Uranium-235, used for nuclear power generation, has brought radioactive waste. It could be released into the environment during reprocessing or recycling of the spent nuclear fuel. Among the radioactive waste nuclides, I-129 occurs problems due to its long half-life (1.57×107 y) with high mobility in the environment. Therefore, it should be captured and immobilized into a geological disposal system through a stable waste form. One of the methods to capture iodine in the off-gas treatment process is to use silver loaded zeolite filter. It converts radioactive iodine into AgI, one of the most stable iodine forms in the solid state. However, it is difficult to directly dispose of AgI itself in an underground repository because of its aqueous dissolution under reducing condition with Fe2+. It must be immobilized in the matrix materials to prevent release of iodine as a result of chemical reaction. Among the matrix glasses, silver tellurite glass has been proposed. In this study, additives including Al, Bi, Pb, V, Mo, and W were added into the silver tellurite glass. The thermal properties of each matrix for radioactive iodine immobilization were evaluated. The glasses were prepared by the melt-quenching method at 800°C for 1 h. Differential scanning calorimetry (DSC) was performed to evaluate the thermal properties of the glass samples. From the study, the glass transition temperature (Tg) was increased by adding additives such as V2O5, MoO3, or WO3 in the silver tellurite glass. The relative electro-static field (REF) values of V2O5, MoO3, and WO3 are about three times higher than that of the glass network former, TeO2. It could provide sufficient electro-static field (EF) to the TeO2 interacting with the non-bridging oxygen forming Te-O-M (M = V, Mo, W) links. Therefore, the addition of V2O5, MoO3, or WO3 reinforced the glass network cohesion to increase the Tg of the glass. The addition of MoO3or WO3 in the silver tellurite glass increased Tg and crystallization temperature (Tc) with remaining the glass stability.

During the treatment of spent nuclear fuel, radioactive iodine is generated in a liquefied or gaseous form in a specific process. In the case of iodine 129, it is a long-lived nuclide with a very long halflife and has high groundwater mobility under repository conditions. Despite showing a low radioactivity value, research on the management of radioactive iodine from a long-term perspective is continuously being performed. Although research has been conducted using borosilicate glass as a medium for solidifying iodine, compatibility of I in borosilicate glass is very small and the volatility is high in the solidification process. So it is not suitable as a solidified substance of iodine. Therefore, studies on other solidification media to replace them are continuously being conducted. Our research team tried to develop a new medium that can contain iodine in a solidified body stably through a simple heat treatment process and can improve problems such as volatility and waste loading. Iodine is captured as AgI in the Ag ion-exchanged zeolite. So, TeO2, Ag2O, and Bi2O3 having a high AgI loading rate were used as main components. It was named TAB after taking the first letter of each element. In previous studies, the physical properties, structure, and chemical stability of TAB materials were confirmed. PCT (Product Consistent test) was performed to confirm chemical stability. It is mainly used to compare the chemical stability of glass materials with other glass materials, but there are limitations in evaluating the long-term chemical stability of materials. In this experiment, we tried to evaluate the long-term stability of TAB and compare it with borosilicate, which is conventionally used to treat radioactive waste. In addition, we tried to understand the leaching behavior inside the TAB medium. For this purpose, ASTM C1308 test was performed for 365 days, and distilled water and KURT groundwater were used as leachates to examine the effect of ions in the groundwater on the solidified body. To analyze the leaching behavior, ICP-MS and ICP-OES analyses were performed, and the cross-section of the sample after leaching was observed through SEM.

본 연구지점은 전라북도 완주군 운주면 고당리에 위치한 왕사봉(300m)의 신갈나무-굴참나무군락으로 주변에 계류가 흐르고 있으며, 소규모 산지와 저수지가 다수 위치해 있다. 또한 인근에 운주계곡 캠핑장이 위치해 있어 인위적 간섭이 잦은 지역이다. 그러므로 산림생태계에서 중요한 역할을 담당하고 있는 곤충 중 하나인 딱정벌레목에 대하여 군집분석을 실시하였다. 조사 방법으로는 직접찾기, 버킷트랩, 함정트랩 을 이용하였으며, 2015년 6월에서 10월까지 매달 1회 채집을 실시하였다. 그 결과 총 24과 70속 88종 417개체의 딱정벌레목을 확인할 수 있었으며, 이 중 붉은칠납작먼지벌레의 우점도가 높은 것으로 나타났다. 군집분석 결과 비교 대상들 간의 우점 정도를 나타내는 지표인 우점도 지수(DI)는 0.434, 군집의 복잡성을 나타내는 다양도 지수(H’)는 3.105으로 확인되었다. 또한 군집 내 종조성의 균일한 정도를 나타내는 종균등도 지수(EI)가 0.693이며 단위 지역에 존재하는 종의 수를 뜻하는 종풍부도 지수(RI)가 14.42로 확인되었다.

This study investigated the antioxidant effect of Hermetia illucens larvae using different extraction temperatures and solvents. We found significant differences in total phenolic content (TPC), total flavonoid content (TFC), an in three antioxidant indexes 2,2-diphenyl-1-picrylhydrazyl (DPPH), 1,1’-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and ferric-reducing antioxidant power (FRAP) contents, among the samples depending on the extraction temperature and solvent used. The sample extracted with water at 45℃ (HIW-45℃) showed the highest TPC, DPPH, ABTS, and FRAP contents, while the sample extracted with water at 90℃ (HIW-90℃) showed the highest TFC. These differences can be due to the different chemical structures of the extracted components. Based on these results, HIW-45℃ was the optimal extraction method for Hermetia illucens. We intend to further investigate the availability of functional materials for Hermetia illucens using this method.

The present study investigated the feasibility of using the ethanolic extract of Hermetia illucens larvae (HIE) as a whitening improvement material. In cell viability assays using B16F1 melanoma cells, no cytotoxicity was recorded up to 200 μg·mL-1 of HIE. Moreover, while tyrosinase inhibitory activity increased, melanin content decreased in a dose-dependent manner, indicating that HIE likely inhibited tyrosine-induced intracellular melanin biosynthesis in B16F1 melanoma cells. Therefore, HIE is expected to serve as a potent whitening improvement material.

A new graft cactus (Gymnocalycium mihanovichii) cultivar 'eumhong' was developed from a cross 'G9331'and 'onkyo G1-13'of G. mihanovichii by in vitro grafting and line selection at National Horticultural Research Institute, Rural Development Administration

A new graft cactus (Gymnocalycium mihanovichii) cultivar “Danhong” was developed from a cross “930903” and “IG9332” of G. mihanovichii by in vitro grafting and line selection at National Horticultural Research Institute, Rural Development Administration i