To achieve permanent disposal of radioactive waste drums, the radionuclides analysis process is essential. A variety of waste types are generated through the operation of nuclear facilities, with dry active waste (DAW) being the most abundant. To perform radionuclides analysis, sample pretreatment technology is required to transform solid samples into solutions. In this study, we developed a dry ashing-microwave digestion method and secured the reliability of the analysis results through a validity evaluation. Additionally, we conducted a comparative analysis of the radioactivity of 94Nb nuclides with and without the chemical separation process, which reduced the minimum detectable activity (MDA) level by more than 65-fold for a certain sample.

The Crab nebula is widely used as a polarization angle calibrator for single-dish radio observations because of its brightness, high degree of linear polarization, and well-known polarization angle over a wide frequency range. However, the Crab nebula cannot be directly used as a polarization angle calibrator for single-dish observations with the Korean VLBI Network (KVN), because the beam size of the telescopes is smaller than the size of the nebula. To determine the polarization angle of the Crab nebula as seen by KVN, we use 3C 286, a compact polarized extragalactic radio source whose polarization angle is well-known, as a reference target. We observed both the Crab nebula and 3C 286 with the KVN from 2017 to 2021 and find that the polarization angles at the total intensity peak of the Crab nebula (equatorial coordinates (J2000) R.A. = 05h34m32.3804s and Dec = 22◦00′44.0982′′) are 154.2◦ ±0.3◦, 151.0◦ ±0.2◦, 150.0◦ ±1.0◦, and 151.3◦ ±1.1◦ at 22, 43, 86, and 94 GHz, respectively. We also find that the polarization angles at the pulsar position (RA = 05h34m31.971s and Dec = 22◦00′52.06′′) are 154.4◦ ±0.4◦, 150.7◦ ±0.4◦, and 149.0◦ ± 1.0◦ for the KVN at 22, 43, and 86 GHz. At 129 GHz, we suggest to use the values 149.0◦ ± 1.6◦ at the total intensity peak and 150.2◦ ± 2.0◦ at the pulsar position obtained with the Institute for Radio Astronomy in the Millimeter Range (IRAM) 30-meter Telescope. Based on our study, both positions within the Crab nebula can be used as polarization angle calibrators for the KVN single-dish observations.

Under physiological conditions, calcium (Ca2+) regulates essential functions of polarized secretory cells by the stimulation of specific Ca2+ signaling mechanisms, such as increases in intracellular Ca2+ concentration ([Ca2+]i) via the store-operated Ca2+ entry (SOCE) and the receptor-operated Ca2+ entry (ROCE). Homer proteins are scaffold proteins that interact with G protein-coupled receptors, inositol 1,4,5-triphosphate (IP3) receptors, Orai1-stromal interaction molecule 1, and transient receptor potential canonical (TRPC) channels. However, their role in the Ca2+ signaling in exocrine cells remains unknown. In this study, we investigated the role of Homer2 in the Ca2+ signaling and regulatory channels to mediate SOCE and ROCE in pancreatic acinar cells. Deletion of Homer2 (Homer2–/–) markedly increased the expression of TRPC3, TRPC6, and Orai1 in pancreatic acinar cells, whereas these expressions showed no difference in whole brains of wild-type and Homer2–/– mice. Furthermore, the response of Ca2+ entry by carbachol also showed significant changes to the patterns regulated by specific blockers of SOCE and ROCE in pancreatic acinar cells of Homer2–/– mice. Thus, these results suggest that Homer2 plays a critical role in the regulatory action of the [Ca2+]i via SOCE and ROCE in mouse pancreatic acinar cells.