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        검색결과 268

        2.
        2023.11 구독 인증기관·개인회원 무료
        Radioactive iodine-129, a byproduct of nuclear fission in nuclear power plants, presents significant environmental and health risks due to its high solubility in water and volatility. Iodine-129, with its half-life of 1.57×1017 years, necessitates safe management and disposal. Therefore, safely capturing and managing I-129 during spent nuclear fuel reprocessing is of paramount importance. To address these challenges, various glass waste forms containing silver iodide have been developed, such as borosilicate, silver phosphate, silver vanadate, and silver tellurite glasses. These glasses effectively immobilize iodine, but the high cost of silver raises affordability concerns. This study introduces CuI·Cu2O·TeO2 glass waste forms for iodine immobilization, a novel approach. The cost-effectiveness of copper, in contrast to silver, makes it an attractive alternative. The CuI·Cu2O·TeO2 glass waste forms were synthesized with varying CuI content (x) in (1-x)(0.3Cu2O·0.7TeO2) glass matrices. Xray diffraction (XRD) confirmed amorphous structures, and X-ray fluorescence (XRF) quantified composition. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy provided insights into structural properties. Durability assessments using a 7-day product consistency test (PCT-A) and inductively coupled plasma-mass spectrometry (ICP-MS) revealed compliance with U.S. glass regulations, making CuI·Cu2O·TeO2 glasses a promising choice for iodine immobilization in radioactive waste.
        3.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The development of food packaging materials with mechanical and antimicrobial properties is still a major challenge. N, P-doped carbons (NPCs) were synthesized. Poly(butylene adipate-co-terephthalate) (PBAT), which has an adverse effect on the environment and affects petroleum resources, has been commonly used for applications as food packaging. The development of PBAT composites reinforced with NPCs and studies on their structure and antimicrobial properties are presented in this study. The composite materials in the PBAT/NPCs were processed by solution casting. The plasticizing properties of NPCs enhanced the mechanical strength of composites produced of PBAT and NPCs. The thermal properties of PBAT composites were enhanced with addition of NPCs, according to thermogravimetric analysis (TGA). After reinforcement, PBAT/NPCs composites became more hydrophobic, according to contact angle measurements. In studies against S. aureus and E. coli food-borne pathogenic bacteria, the obtained composites show noticeably improved antimicrobial activity. The composite materials, according to the results of PBAT and NPCs may be a good choice for packing for food that prevents microorganisms.
        4,000원
        4.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Epoxy-based composites find extensive application in electronic packaging due to their excellent processability and insulation properties. However, conventional epoxy-based polymers exhibit limitations in terms of thermal properties and insulation performance. In this study, we develop epoxy-based siloxane/silica composites that enhance the thermal, mechanical, and insulating properties of epoxy resins. This is achieved by employing a sol–gelsynthesized siloxane hybrid and spherical fused silica particles. Herein, we fabricate two types of epoxy-based siloxane/ silica composites with different siloxane molecular structures (branched and linear siloxane networks) and investigate the changes in their properties for different compositions (with or without silica particles) and siloxane structures. The presence of a branched siloxane structure results in hardness and low insulating properties, while a linear siloxane structure yields softness and highly insulating properties. Both types of epoxy-based siloxane/silica composites exhibit high thermal stability and low thermal expansion. These properties are considerably improved by incorporating silica particles. We expect that our developed epoxy-based composites to hold significant potential as advanced electronic packaging materials, offering high-performance and robustness.
        4,000원
        5.
        2023.07 구독 인증기관 무료, 개인회원 유료
        Food waste is a major sustainable development problem in the world, and the promotion of ugly food may help address this issue. According to cue utilization theory and the VAB model, the primary purpose of this research is to investigate the role of green packaging in ugly food with multiple internal and external cues. A conceptual model with eight hypotheses are proposed. Conclusion, contributions of study and research limitations are finally shown.
        5,800원
        6.
        2023.07 구독 인증기관·개인회원 무료
        Food waste is a major sustainable development problem in the world, and the promotion of ugly food may help address this issue. According to cue utilization theory and the VAB model, the primary purpose of this research is to investigate the role of green packaging in ugly food with multiple internal and external cues. A conceptual model with eight hypotheses are proposed. Conclusion, contributions of study and research limitations are finally shown.
        7.
        2023.07 구독 인증기관 무료, 개인회원 유료
        There has been almost 26 years since science of marketing has developed in Mongolia and there has been significant progress in acquiring and using its findings. Business companies’ leadership have become aware of the importance of this science and see marketing as business philosophy and understand that analyzing the market, business environment and conditions by consumers is the key to success. Today’s society demands from marketing professionals’ delicacy and taking into account consumers’ needs and creating new needs and new means of consumption. Main purpose of business entities is to be aware of consumer needs, to establish its position on the market and to be successful. In order to provide consumers with the best products and keep them at the center of their attention it is important to establish optimal ratio of marketing factors that would most efficiently influence consumers with different behaviors.
        4,000원
        8.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With the rapid development of flexible wearable electronic products, flexible all graphene-based supercapacitors (FGSCs) with reduced graphene oxide rGO//graphene oxide (GO)//rGO structure have attracted substantial attention due to their unique structures and energy storage mechanism. However, restricted by design idea and preparation technology, improvement of capacitance performance for the FGSCs is not obvious recently. Herein, we demonstrate that an interface integration strategy of constructing the high-performance FGSCs with compact structure. Hydroquinone (HQ)-modified rGO (HQ-rGO) films (electrode materials) and sulfuric acid-intercalated GO films (electrolyte/separator) are assembled into the FGSCs utilizing hydrogen bonding and capillary contractility. The HQ further improves the electrochemical capacitance of electrode materials. The synergistic effect of the hydrogen bonding and capillary contractility guarantees compact and stable structure of the device. The resulting FGSCs exhibit an excellent areal capacitance of 804.6 mF cm− 2 (@2 mA cm− 2) and 441 mF cm− 2 (@30 mA cm− 2), and their highest energy and power densities can achieve 109.5 μWh cm− 2 and 21,060 μW cm− 2, respectively. These performances are superior to other all-in-one graphene-based SCs reported. Therefore, the construction technology of the FGSCs is a promising for developing all graphene-based SCs with high-performance.
        4,000원
        9.
        2023.05 구독 인증기관·개인회원 무료
        Decommissioning of Nuclear Power Plant (NPP) projects in South Korea starts with permanent shutdown of Kori unit 1 and Wolsung unit 1. It is important to establish a treatment and disposal method for radioactive waste generated during the decommissioning of the nuclear power plants. Large quantities of the wastes during decommissioning of NPP are generated in a short period of time and the wastes have various types and characteristics. For efficient decommissioning of NPP process, the radioactive waste is classified by types and each treatment method and packaging concept is presented respectively in this paper. Radioactive waste generated during decommissioning of NPP is classified into reactor vessel, reactor internals, metals, Dry Active Waste (DAW), concreate, spent fuel storage rack, spent resin and spent filter, etc., and the packaging concept for each type should be established to meet the waste acceptance criteria. Major waste acceptance criteria requirements include nuclides concentration, filling rate, free water, surface radiation does rate and weight. Radioactive waste containers can be classified into packaging containers, transport containers, and disposal containers. The packaging container is used to contain, transport, and store radioactive waste within the radiation control area, and a control number has been assigned as a radioactive waste drum after the final treatment has been completed. The transport container is used for transporting radioactive waste filled-containers from a radiation control area through an uncontrolled area. In this paper, the concept of disposal of dismantled radioactive waste and packaging methods were reviewed in comprehensive consideration of domestic radioactive waste transport and storage regulations, permanent disposal environment, and development status of large containers.
        10.
        2023.05 구독 인증기관·개인회원 무료
        In order to permanently dispose of radioactive waste drums generated from nuclear power plants, disposal suitability must be demonstrated and the nuclides and radioactivity contained in the waste drums, including those in the shielding drums, must be identified. At present, reliable measurements of the nuclide concentration are performed using drum nuclide analysis devices at power plants and disposal facilities during acceptance inspection. The essential functions required to perform nuclide analysis using the non-destructive assay system are the correction for self-attenuation and the dead time correction. Until now, measurements have mainly been performed for drums containing solid waste such as DAW drums using SGS calibration drums with ordinary iron drums. However, for drums containing non-uniform radioactive waste, such as waste filters embedded in cement within shielding drums, a separate calibration drum needs to be produced. In order to produce calibration drums for shielded and embedded waste drums, the design considered the placement of calibration sources, setting of shielding thickness, correction for medium density, and cement mixing ratio. Based on these considerations, three calibration drums were produced. First, a shielding drum with an empty interior was produced. Second, a density correction drum filled with cement was produced to create apparent density on the surface of the shielding drum. Third, a physical model drum was produced containing a mock waste filter and cement filled in the shielding drum.
        11.
        2023.05 구독 인증기관·개인회원 무료
        The spent filters used to purify radioactive materials and remove impurities from primary systems at nuclear power plants (NPPs) have been stored for long periods in filter storage rooms at NPPs due to concerns about the unproven safety of the treatment method, absence of disposal facilities, and risk of high radiation exposure. In the storage room at Kori Unit 1, there are approximately 227 spent filters of 9 different types. The radiation dose rates of filters range from 0.01 to 500 mSv/hr. Recently, a comprehensive plan has been established for the treatment and disposal of radioactive waste that has not yet been treated to facilitate decommissioning of NPPs. As a follow-up measure, compression and packaging optimization processes are being developed to treat the spent filters. KHNP plans to dispose of the spent filters after compressing, packaging, and immobilizing them. However, the spent filters are currently stored without being sorted by type or radiation intensity. If the removal and packing of the filters are done randomly without a plan for the order of withdrawal and subsequent processes, issues may arise such as a decrease in drum loading efficiency and exceeding the dose limit of the package. In this study, the number of drums needed to pack the spent filters was calculated, considering the filter size, weight, quantity, dose rate, shielding thickness of drum, and loadable quantity in a shielding drum (SD). Then, the spent filters that can be loaded on each drum were classified into one group. In addition, the withdrawal order for each group was set so that the filter withdrawal, compression, and packaging processes could be performed efficiently. The spent filter groups are as follows: (1) compression/12 cm SD (17 groups), (2) compression/16 cm SD (6 groups), (3) non-compression/ intermediate storage container (17 groups, additional radiation attenuation required due to high dose rate), and (4) unclassified (5 groups, determined after measurement due to lack of filter information). The withdrawal order of the groups was determined based on several factors, including visual identification of the filter, ease of distribution after withdrawal, work convenience, and safety. Due to the decay of radioactivity over time, the current dose rate of the spent filters is expected to be much lower than at the time of waste generation. Therefore, in the future, sample filters will be taken from the storage room to measure their radioactivity and radiation dose rate. Based on these measurements, a database of radiological characteristics for the 227 filters will be created and used to revise the filter grouping.
        14.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was designed to evaluate the objective meat qualities of Hanwoo longissimus lumborum muscle after a period of long-term storage (40 days) in which conditions similar to those under which the meat would be stored for export to the Hong Kong beef market were simulated. Twelve LL muscles were sampled from animals slaughtered the previous day at a commercial beef export abattoir and assigned to one of three groups. Each group was subjected to a different packaging condition; Shrink film packed (SFP), vacuum packed (VP), or modified atmosphere packed (MAP)(O2/60%, CO2/40%). Objective meat qualities were assessed at day 1, 7, 21 and 40 of storage. Different Packaging conditions had no noticeable influence on cooking loss significantly. However, the moisture content in both the SFP and MAP groups tended to decline in a linear manner with storage periods throughout the 40 days period. Drip loss of MAP (5.68%) group was much higher in the SFP (3.18%) and VP (2.64%) groups at storage day 40. Redness (CIE a*) of meat color responded in a significant and completely different manner to each packaging method. Redness significantly (p<0.05) and continuously increased 17.51 at day 1 to 20.41 at day 40 in VP group, while MAP linearly dropped and ultimately reached 10.6 after 40 days of aging (p<0.05), at which point the meat had a brown color. Tests of Warner-Bratzler shear force (WBSF) indicated that the tenderness levels of the ready-for-export Hanwoo LL muscles were acceptable 7 days postmortem in the SFP and VP groups, however there was no significant difference between each group. Our gathered data suggests that the packaging method selected for export determines how well the objective qualities of the beef hold up, and indicate that VP is likely the most reliable method.
        4,000원
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