This study evaluated how acid treatment affects the ability of customized beads of activated carbon (BAC) to remove formaldehyde from air. Two different acids (hydrofluoric acid and sulfuric acid) were used to modify the surface of BAC prepared from a polymer material. The acid-modified BACs were further subjected to heat treatment. Physical and chemical characteristics of modified and unmodified BACs were investigated using nitrogen adsorption, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray fluorescence, and X-ray photoelectron spectroscopy. Formaldehyde removal was evaluated under both dry and moist conditions. From the results, acid treatment clearly improved the adsorption performance, especially under the moist condition. Qualitative and quantitative surface analyses were conducted, mainly to examine the amount of O-bonds after acid treatment and the formation of S–O or Cl–O on BAC.

본 논문에서는 외계 행성에서 주어진 임무를 모두 수행하여 클리어하는 탑 뷰 슈팅 게임을 제안한다. 제안 하는 게임을 진행한 플레이어 45명의 로그 기록과 설문 조사 결과를 분석하여, 몰입감, 플레이 패턴의 다양 성, 접근성을 중심으로 제안하는 게임의 특징을 살펴보고자 한다. 첫째, 제안한 게임은 더 높은 몰입감을 위 해 스토리 애니메이션과 오디오를 제공한다. 실험 결과 시각, 청각적 방면으로 몰입감을 효과적으로 제공하 고 있어 대다수의 플레이어가 스토리 애니메이션을 건너뛰지 않고 끝까지 시청했다. 둘째, 제안하는 게임은 더 다양한 플레이 패턴으로 즐길 수 있다. 실험 결과 수많은 경우의 수가 존재하는 무기와 스킬을 선택할 수 있게 하였기 때문에 대부분의 플레이어가 선택하는 스킬들이 서로 겹치지 않고 다양한 방식으로 게임을 플레이할 수 있다. 플레이 패턴이 다양한 만큼 더 게임을 오랫동안, 더 재미있게 즐길 수 있다. 셋째, 제안한 게임은 맵을 비교적 단순하게 구성하였다. 그런데, 호기심 많은 일부 플레이어들이 미션과 직접 관련이 없는 경로를 찾아서 길을 헤매는 경우가 나타났다. 이로 인해, 플레이어들이 게임을 다시 한번 진행하고자 하는 경향이 나타났다.

Nonalcoholic fatty liver disease (NAFLD) is recognized one of the leading metabolic diseases globally, and the younger age population with the disease is rapidly growing, especially in developed countries. Since there has been no approved medicine, losing weight is known to be the only best remedy to control or reverse the disease. Recently, the field of microbiome has attracted much attention to offer more practical choices for patients. Here, we provide experimental evidence that Streptococcus thermophilus LM1012 (LM1012), a safe probiotic strain, is effective for improving NAFLD indexes. In the methionine-choline deficient (MCD) diet induced C57BL/6 mouse model, administration of LM1012 promoted marked reductions of aspartate transaminase (23.8%), total bilirubin (27.8%), hydroxycholesterol (64.2%), triglyceride (29.7%) and IL-1β (68.3%) compared to the MCD diet alone group. Also, the histopathological data imply that LM1012 inhibited fat accumulation and inflammation in the liver, which are the key biomarkers for progression of the disease. Together, these findings suggest that human consumption of LM1012 as a healthy nutritional supplement, may be helpful in reducing the risk of liver damages in NAFLD patients.

According to the ‘Regulations on the Delivery of Low and Medium Level Radioactive Waste’, Notification No. 2021-26 of the Nuclear Safety and Security Commission, a history of radioactive waste and a total amount of radioactivity in a drum are mandatory. At this time, the inventory of radionuclides that make up more than 95% of the total radioactivity contained in the waste drum should be identified, including the radioactivity of H-3, C-14, Fe-55, Co-58, Co-60, Ni-59, Ni-63, Sr- 90, Nb-94, Tc-99, I-129, Cs-137, Ce-144, and total alpha. Among nuclides to be identified, gamma-emitting nuclides are usually analyzed with a gamma ray spectrometer such as HPGe. When a specific gamma-ray is measured with a detector, several types of peaks generated by recombination or scattering of electrons are simultaneously detected in addition to the corresponding gamma-ray in gamma-ray spectroscopy. Among them, the full energy peak efficiency (FEPE) with the total gamma energy is used for equipment calibration. However, this total energy peak efficiency may not be accurately measured due to the coincidence summing effect. There are two types of coincidence summing: Random and True. The random coincidence summing occurs when two or more gamma particles emitted from multiple nuclides are simultaneously absorbed within the dead time of the detector, and this effect becomes stronger as the counting rate increases. The true coincidence summing is caused by simultaneous absorption of gamma particles emitted by two or more consecutive energy levels transitioning from single nuclide within the dead time of the detector. This effect is independent of the counting rate but affected by the geometry and absolute efficiency of the detector. The FEPE decreases and the peak count of region where the energy of gamma particles is combined increases when the coincidence summing occurs. At the Radioactive Waste Chemical Analysis Center, KAERI, samples with a dead time of 5% or more are diluted and re-measured in order to reduce the random coincidence summing when evaluating the gamma nuclide inventory of radioactive waste. In addition, a certain distance is placed between the sample and the detector during measurement to reduce the true coincidence summing. In this study, we evaluate the coincidence summing effect in our apparatus for the measurement of radioactive waste samples.

High Integrity Container (HIC) made of polymer concrete was developed for the efficient treatment and safe disposal of radioactive spent resin and concentrate waste in consideration of the disposal requirements of domestic disposal sites. Permission for application of Polymer Concrete High Integrity Container (PC-HIC) to the domestic nuclear power plants (NPPs) has been completed or is under examination by the regulatory agency. In the case of 860 L PC-HIC for very-low-level-waste (VLLW) or low low-level-waste (LLW), the application of four representative NPPs has been approved, and the license for extended application to the rest NPPs is also almost completed. A licensing review is also underway to apply 510 L PC-HIC for intermediate and low-level-waste (ILLW) to representative nuclear power plants. In order to handle and efficiently store and manage PC-HICs and high-dose PCHIC packages, a gripper device that can be remotely operated and has excellent safety is essential, and the introduction of NPPs is urgent. The conventional gripper device developed by the PC-HIC manufacturer for lifting test to evaluate the structural integrity of PC-HIC requires a rather wide storage interval due to its design features, and does not have a passive safety design to handle heavy materials safely. In addition, work convenience needs to be reinforced for safety management of high radiation work. Therefore, we developed a conceptual design for a gripper device with a new concept to minimize the work space by reflecting on-site opinions on the handling and storage management conditions of radioactive waste in NPPs, and to enhances work safety with the passive safety design by the weight of the package and the function of checking the normal seating of the device and the normal operation of the grip by the detector/indicator, and to greatly improves the work efficiency and convenience with the wireless power supply function by rechargeable battery and the remote control function by camera and wireless monitoring & control system. Through design review by experts in mechanical system, power supply and instrumentation & control fields and further investigations on the usage conditions of PC-HICs, it is planned to facilitate preparations for the application of PC-HIC to domestic NPPs by securing the technical basis for a gripper device that can be used safely and efficiently and seeking ways to introduce it in a timely manner.