Se-79, a fission product of uranium, is present in spent nuclear fuel. Selenium is volatilized from the spent nuclear fuel during the pretreatment of pyroprocessing, and a filter composed of calcium oxide can capture gaseous selenium in the form of CaSeO3. Because Se-79 has a long half-life (3.27E5 years) and selenite ions have high mobility in groundwater, they must be immobilized in a chemically stable form for final disposal. This study used a composition of 50 TeO2 - 10 Al2O3 - 10 B2O3 - 10 Na2O - 10 CaO - 10 ZnO (mol%). High-purity powders of TeO2, Al2O3, H3BO3, Na2CO3, CaCO3, and ZnO were used as glass precursors. The mixed powders were placed in alumina crucibles and melted in an electric furnace under an ambient atmosphere at 800°C for 1 h before being cast on a carbon mold. The obtained glasses were ground into fine powders and then mixed with CaSeO3 powders. The powders were melted in alumina crucibles at 800°C for 1 h. To simulate a seleniumcaptured calcium filter, CaSeO3 was synthesized by a precipitation method using sodium selenite (Na2SeO3) and calcium nitrate (Ca(NO3)2) solutions. The glass samples were analyzed by an X-ray diffractometer (XRD). Retention of Se in tellurite glasses was analyzed by an X-ray fluorescence spectrometer (XRF) and inductively coupled plasma (ICP). The chemical durability of tellurite glass was evaluated through the PCT method.

Magnesium potassium phosphate cements (MKPCs) are prepared by the acid-base reaction of dead burned magnesia (MgO) and monopotassium phosphate (KH2PO4). Low-pH cementitious materials such as MKPCs are currently of interest for the geological disposal of nuclear waste. MKPCs have advantages such as high early strength, high bonding strength, small drying shrinkage, low permeability, and high sulfate resistance. According to the results of previous studies, it is known that cesium, strontium, and cobalt are immobilized in the form of MgCsxK1−xPO4·6H2O, MgxSr1−xKPO4·6H2O, and Co3(PO4)2, respectively, in MKPCs. However, these results were predicted based on thermodynamic data, not directly observed precipitates to clearly show the evidence. Therefore, in this study, we directly analyzed the immobilized forms of Cs, Sr, and Co, respectively. CsNO3, Sr(NO3)2, and Co(NO3)2·6H2O powders (0.3 mol each) were mixed individually in each of the MKPC suspensions. The suspensions in which KH2PO4 was dissolved were pH 4.3 and the dissolution of MgO decreased the H+ concentration, raising the pH close to 11. The hydration products according to pH evolution in the MKPC suspensions were analyzed, and the change in the concentration of ions in the aqueous solution was also measured. An aqueous solution was obtained using a syringe filter (0.45 μm) to analyze the ion concentrations in the solution of the suspension. The collected solutions were diluted with nitric acid and analyzed using inductively coupled plasma mass spectrometry. To characterize the solid phases, the suspensions were obtained with a pipette at specific times and filtered under a vacuum in a Buchner funnel. Because the amounts of hydration products including Cs, Sr, and Co were small, it was not observed by XRD and TGA analysis, but their components could be analyzed by SEM-EDS. The final precipitate forms of Cs, Sr, and Co in the MKPC matrix are MgCsPO4·6H2O, SrHPO4, and Co3(PO4)2·8H2O, respectively.

IEC 60079-10-1 edition 2.0, the global standard for hazardous area classification, was newly revised in 2015. There are many differences compared to the previous edition 1.0 version, first released in 2008, so it has caused confusion in the industry. In case of edition 1.0, the hazardous area extent can be derived through the mathematical formula, but in case of edition 2.0, there was the problem that the exact hazardous area extent was not known because of the mathematical formula of the plot for applying the hazardous area extent was not presented. In this study, we converted the plot introduced in edition 2.0 to CAD format and derived the plot as the mathematical equations. Through this, we suggest the hazardous area extent formula of three states (heavy gas, diffusive, jet). As the IEC committee did not provide the mathematical formula of the hazardous area extent according to the release characteristic, it is impossible to apply the exact hazardous area extent. In this study, a mathematical approach was derived for the plot introduced in edition 2.0, which can reduce the confusion of the applying hazardous area extent.

한국 서남부 농업생태계는 다양한 크기로 분산되어 있는 산림지대가 경작지 사이에 분포되어 있는 형태를 가지고 있다. 이 연구에서는 농업생태계 산림지대에 분포하는 나방 군집과 산림지대에 분포하는 나방 군집을 비교하여 파편화된 농촌 지역 나방 다양성은 산림지대보다 낮지만 생물 이동에 따른 베타 다양성은 더 높을 것으로 예상하였다. 이 연구에 이용한 나방은 종 다양성과 분류학적 정보가 풍부하며, 자외선등을 이용한 정량적 채집이 가능한 분류군이다. 또한 환경변화를 나타내는 지표그룹으로 활발히 이용되고 있으며 기주 특이성이 있어 서식지에 따른 종 구성 차이가 있기 때문에 서식지 유형에 따른 종 구성을 파악하기 적합하다고 여겨진다. 2018년 5월부터 10월까지 한국 서남부 지역인 전라남도 나주시, 무안군, 해남군 등지의 산림과 농촌경관내 산림지역에서 UV등 트랩을 사용하여 나방을 채집하였다. 조사는 농경산림지대와 자연산림지대를 선정한 뒤 나방을 채집하였으며 각 지점별 산림 특성에 따라 다양성 양상을 비교 분석 하였다. 이 연구결과를 토대로 같은 지역에 위치한 나방군집이 경관구조의 이질성에 따라 어떠한 양상을 보이는지 알 수 있을 것으로 예상된다.

Melatonin has an important role as anti-oxidative effect and reducing of endoplasmic reticulum(ER)-stress on oocyte maturation and embryo development. Under ER-stress condition, unfolding protein response (UPR) is a defence mechanism in mammalian cells. Recently, regulation of UPR signaling genes are involved in oocyte maturation, embryo development and female reproduction. However, there is no report on the role of melatonin for UPR signaling and ER-stress mediated apoptosis during pig oocyte maturation progression. Moreover, the changes of UPR genes expression according to the porcine oocyte maturation is not yet fully understood. Here, we investigated the changes of UPR signal (BIP/GRP78, ATF4, p90/p50ATF6, and XBP1) and ER-stress apoptotic factor CHOP genes expressions in porcine oocyte maturation by Western blot and RT-PCR analysis. During oocyte maturation, UPR marker and CHOP genes expressions were significantly increased in matured oocytes or cumulus-oocyte complexes (COCs). UPR markers expressions were significantly increased by ER-stress inducer, tunicamycin (Tm), treated (1, 5, 10 μg/ml) groups in a dose-dependent manner compared with control group. To confirm the reducing of ER-stress by melatonin (0.1 μM), we were compared to the effects of ER-stress inhibitor, TUDCA (200 μM), after pre-treated Tm (5 μg/ml) for 22 h maturation. Expressions of UPR markers and meiotic maturation were recovered by melatonin (0.1 μM) in COCs. And, we observed the role of Grp78/Bip as UPR signaling beginning marker using siRNA. In result, reduction of Grp78/Bip gene expression by siRNA was induced the inhibition of oocyte maturation (32.5±10.1 vs control; 77.8±5.3), and p50ATF6 protein level was significantly decreased (p<0.001) in cultured COCs for 44 h. In addition, these results were recovered through the addition of melatonin (0.1 μM) or TUDCA (200 μM) in maturation medium. These results demonstrated that the regulation of UPR signaling via Grp78/Bip gene induction plays a critical role in porcine oocyte maturation in vitro. Furthermore, this present study first confirmed a functional link between inhibition effect of ER-stress by melatonin and regulating of UPR signaling in porcine oocyte maturation. In conclusion, melatonin improves the oocyte maturation and cumulus cells expansion of COCs through the regulation of UPR signal pathway by BIP/GRP78 against the ER-stress during porcine oocyte maturation periods.

Active Galactic Nuclei (AGN) with bright radio jets oer the opportunity to study the structure of and physical conditions in relativistic out ows. For such studies, multi-frequency polarimetric very long baseline interferometric (VLBI) observations are important as they directly probe particle densities, magnetic eld geometries, and several other parameters. We present results from rst-epoch data obtained by the Korean VLBI Network (KVN) within the frame of the Plasma Physics of Active Galactic Nuclei (PAGaN) project. We observed seven radio-bright nearby AGN at frequencies of 22, 43, 86, and 129 GHz in dual polarization mode. Our observations constrain apparent brightness temperatures of jet components and radio cores in our sample to > 108:01 K and > 109:86 K, respectively. Degrees of linear polarization mL are relatively low overall: less than 10%. This indicates suppression of polarization by strong turbulence in the jets. We found an exceptionally high degree of polarization in a jet component of BL Lac at 43 GHz, with mL  40%. Assuming a transverse shock front propagating downstream along the jet, the shock front being almost parallel to the line of sight can explain the high degree of polarization.

In this paper we introduce the Plasma Physics of Active Galactic Nuclei project, which is an ongoing experiment with Korean VLBI Network (KVN) and KVN and VERA Array (KaVA) to study multi- frequency polarimetric properties on parsec scales of active galaxies. The goal of the project is to improve our understanding of fundamental jet physics, especially evolution of the relativistic out ow coupled with the large-scale magnetic field. We selected six radio-loud AGN as our targets. So far we (i) detected resolved emissions regions at 86 and 129 GHz on VLBI scales, (ii) constructed 2D spectral index maps of the out ows, and (iii) found polarizations at 22 and 43 GHz for a few targets. Here we present spectral index distributions of 3C 120 between 22 and 43 GHz and a linear polarization map of BL Lac at 43 GHz obtained with KVN.