검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

분야

    발행연도

    -

      검색결과 2,408

      1.
      2025.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
      This study used an in-house beta version code, developed on the Microsoft® Excel platform and based on the Regulatory Guide 1.109 model, for radiation dose calculations. The results were compared with those of NRCDose3 Code Version 1.1.4. Although most results were compatible, five significant discrepancies were identified. First, potential errors in the effective dose for 3H inhalation and ingestion were due to inadequate incorporation of dose coefficients based on chemical forms or absorption types in the GASPAR module. Second, potential errors in 14C effective doses resulted from incorrect application of age-specific consumption values and dose coefficients. Third, potential errors for 131I inhalation doses occurred due to inadequate consideration of dose coefficients for chemical form or absorption type in the GASPAR. Fourth, potential errors in equivalent dose for radionuclides (e.g., 60Co and 131I) were caused by inconsistencies in the ordering of organs or tissues in dose coefficients and output files. Fifth, in the LADTAP module, when “Salt water” was selected and the International Commission on Radiological Protection Publication 72 was applied, liquid effluent doses were incorrectly output for only three age groups instead of six. This study analyzes these errors and proposes interim corrective measures to ensure accuracy pending software revisions.
      6,000원
      3.
      2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
      Ceramic materials have become essential due to their high durability, chemical stability, and excellent thermal stability in various advanced industries such as aerospace, automotive, and semiconductor. However, high-performance ceramic materials face limitations in commercialization due to the high cost of raw materials and complex manufacturing processes. Aluminum borate (Al₁₈B₄O₃₃) has emerged as a promising alternative due to its superior mechanical strength and thermal stability, despite its simple manufacturing process and low production cost. In this study, we propose a method for producing Al₁₈B₄O₃₃ spherical powder with increased uniformity and high flowability by controlling the particle size of B₂O₃. The content ratio of the manufactured Al18B4O33 spherical powder was Al2O3: B2O3 = 87:13, and it exhibited a 17% reduction in the Hausner ratio (1.04) and a 29% decrease in the angle of repose (23.9°) compared to pre-milling conditions, demonstrating excellent flowability.
      4,000원
      4.
      2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
      Natural products have recently emerged as promising candidates for anticancer therapeutics. However, research on their use as adjuvants to existing chemotherapeutic agents in the treatment of oral squamous cell carcinoma (OSCC) remains limited. This study investigated the potential of METO, a methanol extract derived from Thuja orientalis, to induce apoptosis and its underlying mechanisms in the OSCC cell line HSC4. The results demonstrated that METO induces apoptosis in HSC4 cells, which is likely mediated through the activation of the ERK and JNK pathways, both of which were observed to be activated in METO-treated cells. Additionally, METO-induced apoptosis appears to involve signaling pathways associated with SOCS3 and p53. These findings highlight that METO exhibits strong anticancer activity in OSCC cells and suggest its potential as a promising chemotherapeutic agent for OSCC treatment.
      4,000원
      6.
      2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
      For metal-free carbocatalysts, heteroatom doping and hierarchically porous structure are the significant factors to improve their catalytic performances. Herein, N-, P-co-doped hierarchically porous carbon fiber (NPC–2–800) was prepared by pyrolyzing bamboo pulp in combination with ( NH4)2HPO4 and activator K2CO3. It was found that ( NH4)2HPO4 not only provides N and P atoms, but also significantly affect the morphology and pore structure of the porous carbon. An appropriate dosage of ( NH4)2HPO4 facilitates the formation of hierarchically porous carbon fiber in NPC-2–800. Whereas, the carbon fragments with only micropores were obtained in absence of ( NH4)2HPO4. The hierarchical porosity and the co-doping of N and P atoms in the NPC-2–800 contribute to its outstanding catalytic performances in the 4-Nitrophenol (4-NP) reduction assisted by NaBH4. The NPC-2–800 exhibits an attractive turnover frequency (TOF) value of 4.29 × 10– 4 mmol mg− 1 min− 1, a low activation energy (Ea) of 24.76 kJ/mol, and an acceptable recyclability for 7 cycles without obvious decrease in activity. Kinetics analyses suggest that the 4-NP reduction proceeds through the Langmuir–Hinshelwood model. In addition, the NPC-2–800 can also efficiently catalyze the 2-NP and 3-NP reduction. Moreover, in the real water body, the NPC-2–800 also showed superior catalytic activity to catalyze 4-NP reduction. This study provides an efficient catalyst for pollutant conversion and elimination as well as guidelines for designing versatile carbon-based catalysts.
      4,300원
      7.
      2024.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
      Solar energy has been recognized as an alternative energy source that can help address fuel depletion and climate change issues. As a renewable energy alternative to fossil fuels, it is an eco-friendly and unlimited energy source. Among solar cells, thin film Cu2ZnSn(S,Se)4 (CZTSSe) is currently being actively studied as an alternative to heavily commercialized Cu (In,Ga)Se2 (CIGS) thin film solar cells, which rely upon costly and scarce indium and gallium. Currently, the highest efficiency achieved by CZTSSe cells is 14.9 %, lower than the CIGS record of 23.35 %. When applied to devices, CZTSSe thin films perform poorly compared to other materials due to problems including lattice defects, conduction band offset, secondary phase information, and narrow stable phase regions, so improving their performance is essential. Research into ways of improving performance by doping with Germanium and Cadmium is underway. Specifically, Ge can be doped into CZTSSe, replacing Sn to reduce pinholes and bulk recombination. Additionally, partially replacing Zn with Cd can facilitate grain growth and suppress secondary phase formation. In this study, we analyzed the device’s performance after doping Ge into CZTSSe thin film using evaporation, and doping Cd using chemical bath deposition. The Ge doped thin film showed a larger bandgap than the undoped reference thin film, achieving the highest Voc of 494 mV in the device. The Cd doped thin film showed a smaller bandgap than the undoped reference thin film, with the highest Jsc of 36.9 mA/cm2. As a result, the thin film solar cells achieved a power conversion efficiency of 10.84 %, representing a 20 % improvement in power conversion efficiency compared to the undoped reference device.
      4,000원
      8.
      2024.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
      In this study, ferric phosphate precursors were prepared by controlling precipitation time, and the resulting LiFe PO4 active materials were thoroughly investigated. Microscale LiFePO4 cathode materials, designed for high energy density at the cell level, were successfully synthesized through a 10 h co-precipitation. As the reaction time increased, smaller primary particles were aggregated more tightly, and the secondary particles exhibited a more spherical shape. Meanwhile, ammonia did not work effectively as a complexing agent. The carbon coated LiFePO4 (LiFePO4/C) synthesized from the 10 h ferric phosphate precursor exhibited larger primary and secondary particle sizes, a lower specific surface area, and higher crystallinity due to the sintering of the primary particles. Enhanced battery performance was achieved with the LiFePO4/C that was synthesized from the precursor with the smaller size, which exhibited the discharge capacity of 132.25 mAh ‧ g-1 at 0.1 C, 70 % capacity retention at 5 C compared with 0.1 C, and 99.9 % capacity retention after the 50th cycle. The better battery performance is attributed to the lower charge transfer resistance and higher ionic conductivity, resulting from smaller primary particle sizes and a shorter Li+ diffusion path.
      4,000원
      9.
      2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
      Aluminum-based composites are in high demand in industrial fields due to their light weight, high electrical conductivity, and corrosion resistance. Due to its unique advantages for composite fabrication, powder metallurgy is a crucial player in meeting this demand. However, the size and weight fraction of the reinforcement significantly influence the components' quality and performance. Understanding the correlation of these variables is crucial for building high-quality components. This study, therefore, investigated the correlations among various parameters—namely, milling time, reinforcement ratio, and size—that affect the composite’s physical and mechanical properties. An artificial neural network model was developed and showed the ability to correlate the processing parameters with the density, hardness, and tensile strength of Al2024-B4C composites. The predicted index of relative importance suggests that the milling time has the most substantial effect on fabricated components. This practical insight can be directly applied in the fabrication of high-quality Al2024-B4C composites.
      4,000원
      10.
      2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
      This review examines the microstructural and mechanical properties of a Ti-6Al-4V alloy produced by wrought processing and powder metallurgy (PM), specifically laser powder bed fusion (LPBF) and hot isostatic pressing. Wrought methods, such as forging and rolling, create equiaxed alpha (α) and beta (β) grain structures with balanced properties, which are ideal for fatigue resistance. In contrast, PM methods, particularly LPBF, often yield a martensitic α′ structure with high microhardness, enabling complex geometries but requiring post-processing to improve its properties and reduce stress. The study evaluated the effects of processing parameters on grain size, phase distribution, and material characteristics, guiding the choice of fabrication techniques for optimizing Ti-6Al-4V performance in aerospace, biomedical, and automotive applications. The analysis emphasizes tailored processing to meet advanced engineering demands.
      4,000원
      11.
      2024.10 KCI 등재 구독 인증기관·개인회원 무료
      현행 신탁법은 우리 사회가 고령화사회로 급격하게 진행됨에 따라 피 상속인의 의사를 최대한 반영함과 더불어 유연한 재산승계제도를 구축하 기 위하여 구 신탁법에 없던 유언대용신탁을 전격 도입하였다. 신탁법 제59조에서 규정하고 있는 유언대용신탁은 위탁자의 사망 시에 수익자로 지정된 자가 수익권을 취득하는 신탁 또는 위탁자의 사망 이후 에 수익자가 신탁재산으로부터 급부를 받는 신탁을 의미한다. 유언대용신 탁의 도입 이후 관련 시장은 빠르게 성장하고 있고, 필연적으로 유언대 용신탁을 둘러싼 분쟁 또한 증가하는 추세이다. 대법원 2024. 4. 16. 선 고 2022다307294 판결은 이러한 배경에서, ① 유언대용신탁에 있어 수 탁자가 신탁재산에 관한 유일한 수익자가 되는 신탁은 허용될 수 없다고 판단하는 한편, ② 위와 같은 신탁이 설정된 경우 신탁법 제5조 제2항이 규율하고 있는 목적이 위법하거나 불능인 신탁에 해당하여 무효라는 점 을 분명히 하고, 나아가 ③ 이러한 경우라 하더라도 위탁자가 사망하기 전 수익자를 위탁자로 지정하여 수탁자로 하여금 신탁재산을 관리 또는 운용하도록 한 부분은 신탁법 제5조 제3항에 따라 유효하게 존속할 수 있는 가능성이 존재한다는 점을 최초로 확인하였다는 점에서 그 의의가 적지 않다. 다만 잔여재산수익자와 귀속권리자는 엄격히 구별되는 개념이라는 점 을 고려하면 위 판결이 파기환송심에서 추가적으로 심리가 필요한 대상 을 지적하는 과정에서 귀속권리자만 언급하고 잔여재산수익자를 누락한 점과 신탁행위상 잔여재산수익자나 귀속권리자에 관한 지정이 없는 상황 에서 신탁법 제101조 제2항의 유추적용 가능성을 판단하지 않은 점 등 은 아쉬운 대목이다.
      12.
      2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
      PURPOSES : For autonomous vehicles, abnormal situations, such as sudden changes in driving speed and sudden stops, may occur when they leave the operational design domain. This may adversely affect the overall traffic flow by affecting not only autonomous vehicles but also the driving environment of manual vehicles. Therefore, to minimize the traffic problems and adverse effects that may occur in mixed traffic situations involving manual and autonomous vehicles, an autonomous vehicle driving support system based on traffic operation optimization is required. The main purpose of this study was to build a big-data-classification system by specifying data classification to support the self-driving of Lv.4 autonomous vehicles and matching it with spatio-temporal data. METHODS : The research methodology is explained through a review of related literature, and a traffic management index and big-dataclassification system were built. After collecting and mapping the ITS history traffic information data of an actual Living Lab city, the data were classified using the traffic management indexing method. An AI-based model was used to automatically classify traffic management indices for real-time driving support of Lv.4 autonomous vehicles. RESULTS : By evaluating the AI-based model performance using the test data from the Living Lab city, it was confirmed that the data indexing accuracy was more than 98% for the KNN, Random Forest, LightGBM, and CatBoost algorithms, but not for Logistics Regression. The data were severely unbalanced, and it was necessary to classify very low probability nonconformities; therefore, precision is also important. All four algorithms showed similarly good performances in terms of accuracy. CONCLUSIONS : This paper presents a method for efficient data classification by developing a traffic management index to easily fuse and analyze traffic data collected from various institutions and big data collected from autonomous vehicles. Additionally, EdgeRSU is presented to support the driving of Lv.4 autonomous vehicles in mixed autonomous and manual vehicles traffic situations. Finally, a database was established by classifying data automatically indexed through AI-based models to quickly collect and use data in real-time in large quantities.
      4,000원
      19.
      2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
      Building step-scheme (S-scheme) heterojunctions has recently emerged as a highly effective approach for developing superior photocatalysts for water purification. Herein, a C3N5/ Ag3PO4 (CA) S-scheme heterojunction was prepared by in situ growth of Ag3PO4 nanoparticles on 2D C3N5 nanosheets. Notably, under visible-light irridiation, CA exhibited significantly higher activity in the photodegradation of LEVO, which is about 28.38, 2.41, and 2.14 times higher than the rates for C3N5, Ag3PO4, and the mixture, respectively. Based on the radical scavenging experiments, the mechanism for enhanced photocatalytic performance has been analyzed, is attributed to improved interfacial charge separation, the elevated redox potential of photon-generated electrons and holes, and the increased generation of active species resulting from the S-scheme transfer of photoinduced carriers. Additionally, CA demonstrates greater stability than either C3N5 or Ag3PO4 alone in the photo-oxidation of LEVO and the photodegradation of RhB. In essence, this study not only deepens our comprehension of the photocatalytic mechanism of CA, but also pioneers a novel concept for the development of highly effective and stable S-type heterojunction photocatalysts.
      5,100원
      20.
      2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
      Na4MnV(PO4)3 (NMVP) cathode materials have attracted significant attention as potential candidates for grid applications due to their distinctive structure and high theoretical capacity. However, their inadequate electronic conductivity compromises both cycling stability and rate capability, presenting a challenge for practical implementation. To address this issue, we employed a strategy involving Zr4+ doping and dual-carbon coating to enhance the electrochemical performance of NMVP. The resulting Na3.8MnV0.8Zr0.2( PO4)3/C/rGO composite demonstrated markedly improved rate capability (71.9 mAh g− 1 at 60 °C) and sustained cyclic stability (84.8% retention at 2 C after 1000 cycles), as validated through comprehensive kinetics assessments. The enhanced performance can be attributed to the expanded Na-ion pathways facilitated by large size ion doping and the improved electronic conductivity enabled by the dual-layer coating.
      4,000원
      1 2 3 4 5