검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 617

        48.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,300원
        52.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,200원
        53.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        형광 강도 변화를 이용하여 세포막의 위상에 따른 하이드록시부티르산 혼입이 생체막에 미치는 영향을 조사하였다. 구형 인지질 이중층인 소포(vesicle)가 이중 에멀젼 기술을 통해 각 층 단위로 제조되었 다. 소포 내부의 수성에는 아미노나프탈렌트리술폰산디소듐(ANTS)이 캡슐화되었으며, 소광제(quencher) 로 자일렌비스피리디늄브로마이드(DPX)를 소포가 분산된 버퍼에 포함시켰다. 형광 등급은 100% 형광으 로서 DPX가 포함된 완충액의 소포와 0% 형광으로서 ANTS와 DPX의 혼합물이 포함된 완충액의 소포를 고려하여 조정되었다. 소포 용액에 하이드록시부티르산 혼입은 막 구조의 변화를 유도하였으며, 이러한 변 화는 하이드록시부티르산 대 지질의 비율에서 소포의 각 층의 상과 관련이 있는 것으로 관찰된다. 관찰된 결과는 머리 그룹과 꼬리 그룹 모두의 패킹 붕괴에 대한 삼투압 및 체적 효과로 인해 소포의 안정성에 의 존하는 것으로 보인다.
        4,000원
        54.
        2022.10 구독 인증기관·개인회원 무료
        Complexing agents used at various nuclear facilities exist in low- and intermediate level radioactive wastes deposited in the repository site. In addition these will be generated through the degradation of the wastes such as cellulose materials. The presence of chelating agents may possibly affect the safety of the wastes repository by promoting the migration of radionuclides into geosphere. Thus, under Nuclear Safety and Security Commission’s Notice No. 2021-16, the contents of chelating agents in radioactive wastes are required to be determined for the secured disposal. UV-Vis method based on an enzymatic reaction was proved to be in adequate to analyze citric acid in radioactive wastes with complex matrix, especially for concrete. A rapid automated method using ion chromatography (IC) for analysis of citric aicd in concrete samples is developed. This automated method enables a sample solution to measure without pretreatment and a target substance to separate from other concrete admixtures. Also, the developed method here, for radioactive concrete wastes was successfully applied to real samples with lowering a limit of quantification value.
        55.
        2022.10 구독 인증기관·개인회원 무료
        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.
        57.
        2022.10 구독 인증기관·개인회원 무료
        Deep geological disposal is generally accepted to be the most practical approach to handling radioactive wastes. Bentonite has been considered as a buffer material in deep geological disposal repositories (DGR) for high-level radioactive wastes. Evaluating the effect of short-term bentonite alteration on EBS performance has limitations in safety assessment over thousands of years. Information on bentonite characteristics under various conditions obtained from natural systems can be used to evaluate long-term safety of bentonite buffer. The purpose of this study was to investigate mineralogical and physicochemical characteristics of bentonite in the Naah mine located in Yangnam-myeon, Gyeongju-si for a natural analogue of the bentonite barrier in DGR. A total of 15 samples were collected at regular intervals from the bentonite layer and andesitic lapilli tuff (i.e., parent rock) at the boundary with the bentonite layer. The bentonite layer is located at a depth of about 1 m below the ground surface. Each sample was separated into particles < < 75 μm and particles < 2 μm through grinding and sedimentation processes. The separated subsamples were characterized mineralogically and physiochemically using various analytic techniques. Bentonite samples have a similar SiO2/Al2O3 ratio to the parent rock and a lower (Na+K)/Si ratio than the parent rock, indicating depletion of alkali components during bentonitization. The parent rock and bentonite samples have similar mineral composition (i.e., quartz, feldspars, opal-cristobalite-tridymite and montmorillonite). Results of XRD analysis on the randomly distributed particles < 2 μm indicate that bentonite is mostly composed of Ca-montmorillonite, which is a typical dioctahedral smectite. Results of FTIR and VNIR analysis indicate that montmorillonite contained in bentonite is Al-dioctahedral montmorillonite, and Al is substituted with Mg in some octahedron units. The mineralogical and physicochemical characteristics are similar regardless of sampling location. These results suggest that bentonite potentially exposed to weathering, located near the ground surface, has hardly altered.
        1 2 3 4 5