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        검색결과 54,025

        1381.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Si-based anodes are promising alternatives to graphite owing to their high capacities. However, their practical application is hindered by severe volume expansion during cycling. Herein, we propose employing a carbon support to address this challenge and utilize Si-based anode materials for lithium-ion batteries (LIBs). Specifically, carbon supports with various pore structures were prepared through KOH and NaOH activation of the pitch. In addition, Si was deposited into the carbon support pores via SiH4 chemical vapor deposition (CVD), and to enhance the conductivity and mechanical stability, a carbon coating was applied via CH4 CVD. The electrochemical performance of the C/Si/C composites was assessed, providing insights into their capacity retention rates, cycling stability, rate capability, and lithium-ion diffusion coefficients. Notably, the macrostructure of the carbon support differed significantly depending on the activation agent used. More importantly, the macrostructure of the carbon support significantly affected the Si deposition behavior and enhanced the stability by mitigating the volume expansion of the Si particles. This study elucidated the crucial role of the macrostructure of carbon supports in optimizing Si-based anode materials for LIBs, providing valuable guidance for the design and development of high-performance energy-storage systems.
        4,300원
        1382.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Crystalline heptazine carbon nitride (HCN) is an ideal photocatalyst for photocatalytic ammonia synthesis. However, the limited response to visible light has hindered its further development. As a noble metal, Au nanoparticles (NPs) can enhance the light absorption capability of photocatalysts by the surface plasmon resonance (SPR) effect. Therefore, a series of Au NPs-loaded crystalline carbon nitride materials (AH) were prepared for photocatalytic nitrogen fixation. The results showed that the AH displayed significantly improved light absorption and decreased recombination rate of photo-generated carriers owing to the introduction of Au NPs. The optimal 2AH (loaded with 2 wt% Au) sample demonstrated the best photocatalytic performance for ammonia production with a yield of 70.3 μmol g− 1 h− 1, which outperformed that of HCN. This can be attributed to the SPR effect of Au NPs and alkali metal of HCN structure. These findings provide a theoretical basis for studying noble metal-enhanced photocatalytic activity for nitrogen fixation and offer new insights into advances in efficient photocatalysts.
        4,500원
        1383.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Graphitic nitrogen-doped carbon film/nanoparticle composite, in which the films were wrapped and separated by the nanoparticles, was prepared through a simple co-calcination route. Due to its unique porous structure and improved nitrogen content, the as-prepared electrode material could exhibit high specific capacitances of 317.5 F g− 1 at 0.5 A g− 1 and 200.0 F g− 1 at 20 A g− 1, and stable cycling behavior with no capacitance decline after 10,000 cycles in three-electrode system. When assembled in two-electrode capacitor, its specific capacitance could be well kept at 265.5 F g− 1 at 0.5 A g− 1, and thus the supercapacitor with a high energy density of 9.22 Wh kg− 1 was obtained. The superior energy storage properties of the as-prepared material indicate its promising application as high-performance carbon-based electrode for supercapacitors.
        4,300원
        1384.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Coal tar pitch is a raw material that can be made from various carbon materials such as activated carbon, carbon fiber, and artificial graphite through heat treatment. In particular, it is an important raw material used as a binder and impregnated pitch when manufacturing carbon composite materials. In order to improve the physical properties of such a carbon composite material, the content of β-resin is an important factor. Although β-resin plays the role of a binder, it also corresponds to fixed carbon, so it can determine the physical properties after carbonization. In this study, we compared the physical properties of coal tar pitch various temperature ramping rate, and found through Py-GC/MS analysis that intermediate materials were generated by heteroatoms such as oxygen and nitrogen. MALDI-TOF/MS analysis revealed that these intermediate materials overlapped with the molecular weight region of β-resin. Therefore, the content of β-resin is in the following order: 430–5 (12.8 wt%), 430–10 (10.2 wt%), and 430–2 (6.3 wt%), and when 430–5 is used as a binder, the highest density appeared at 1.75 g/cm3. However, such intermediate materials undergo thermal decomposition even at temperatures above 900 °C. As a result, after carbonization, 430–5 had a density of 1.60 g/cm3, which was similar or lower than that of 430–2 (1.72 → 1.63 g/ cm3) and 430–10 (1.73 → 1.61 g/cm3). From these results, it is expected that if the heteroatom content is distributed in an appropriate amount and the heating rate is well controlled, it will be possible to maintain a high density even after carbonization while ensuring a high beta-resin content.
        4,000원
        1385.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, the search on fabrication of highly efficient, stable, and cost-effective alternative to Pt for the hydrogen evolution reaction (HER) has led to the development of new catalysts. In this study, we investigated the electrocatalytic HER activity of the Toray carbon substrate by creating defect sites in its graphitic layer through ultrasonication and anodization process. A series of Toray carbon substrates with active sites are prepared by modifying its surface through ultrasonication, anodization, and ultrasonication followed by anodization procedures at different time periods. The anodization process significantly enhances the surface wettability, consequently resulting in a substantial increase in proton flux at the reaction sites. As an implication, the overpotential for HER is notably reduced for the Toray carbon (TC-3U-10A), subjected to 3 min of ultrasonification followed by 10 min of anodization, which exhibits a significantly lower Tafel slope value of 60 mV/dec. Furthermore, the reactivity of the anodized surface for HER is significantly elevated, especially at higher concentrations of sulfuric acid, owing to the enhanced wettability of the substrate. The lowest Tafel slope value recorded in this study stands at 60 mV/dec underscoring the substantial improvements achieved in catalytic efficiency of the defect-rich carbon materials. These findings hold promise for the advancement of electrocatalytic applications of carbon materials and may have significant implications for various technological and industrial processes.
        4,000원
        1386.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Silicon carbide (β-SiC) was synthesized through an improved sol–gel method, then Ni/SiC catalysts were prepared using a hydrothermal method. The catalysts were characterized using TEM, H2- TPR, CO2- TPD and N2- TPD, etc. The results showed that the synthesized β-SiC had a large specific surface area, promoting the dispersion of Ni species and thus exposing more active sites. The interaction between Ni species and β-SiC contributed significantly to catalytic performance. Furthermore, the strong alkalinity of catalyst could adjust the bond energy of the active metal and N (M–N), which were conducive to desorption of the recombinant N2 from the metal surface, promoting to ammonia decomposition. Among the Ni/SiC catalysts, 30Ni/SiC-700 synthesized with the Ni loading of 30 wt% and calcination temperature of 700 °C, exhibited the optimal ammonia conversion rate of 93.4% at 600 °C under the space speed of 30,000 mL∙gcat −1∙h−1, and demonstrated a long-term stability, suggesting a very promising catalyst in ammonia decomposition.
        4,200원
        1387.
        2024.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Magnons have unique properties, including long propagation length, and can exist in insulators. Magnon valve structures, which consist of two magnetic insulating layers, offer a promising approach for advanced magnetoresistive randomaccess memory (MRAM) technology and an alternative to the limitations of traditional electronic devices. In this study, we investigate a magnon valve structure that incorporates a platinum (Pt) spacer between two magnetic insulator layers, specifically yttrium iron garnet (Y3Fe5O12, YIG). Structural characterization of the YIG/Pt/YIG magnon valve was carried out using X-ray diffraction (XRD) and transmission electron microscopy (TEM), confirming the high-quality growth of the multilayer structure. The magnon valve behavior was assessed through vibrating sample magnetometry (VSM) and spin Seebeck effect (SSE) measurements. Our results demonstrate magnon valve behavior, which becomes apparent as the Pt spacer reaches a thickness sufficient to decouple the magnetization of the YIG layers. The magnon valve ratio of the magnon valve can be modulated, and clarity of the those states can be enhanced.
        4,000원
        1388.
        2024.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study investigates the development of risedronate (RSD)-incorporated polycaprolactone (PCL)/chitosan composite films for potential use in drug delivery systems aimed at bone repair. PCL and chitosan were blended in varying ratios (25 %, 50 %, 75 % PCL), and their miscibility, morphology, and hydrophilicity were analyzed. The effects of incorporating RSD at different concentrations (10-7 to 10-4 M) on MG63 preosteoblast cell proliferation and differentiation were also evaluated. The results demonstrated that blending of the hydrophobic PCL with hydrophilic chitosan was challenging, due to poor miscibility and phase separation. Optimal blending conditions and drying temperatures were essential for homogeneous film formation. The incorporation of RSD influenced cellular behavior, with 50 % PCL showing the most effective cell proliferation and moderate hydrophilicity. However, higher RSD concentrations (10-4 M) inhibited proliferation, while lower concentrations (10-7 M) promoted it. RSD also enhanced osteoblast differentiation, as evidenced by increased alkaline phosphatase (ALP) activity, particularly in 75 % PCL films. These findings suggest that adjusting the PCL/chitosan ratio and RSD concentration can optimize drug release and cellular responses, making this composite system a promising candidate for bone tissue engineering applications.
        4,000원
        1389.
        2024.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study investigates the performance characteristics of electrodeposited (ED) silver nanowires (AgNWs) networks as transparent conducting electrodes (TCEs) considering Cu(In,Ga)Se2 (CIGS) thin-film solar cells. The electrodeposition process uniformly deposits silver onto a network of spin-coated AgNWs, resulting in the enlargement of individual nanowire diameters and the formation of stronger interconnections between the AgNWs. This structural enhancement significantly improves both the electrical conductivity and thermal stability of the ED AgNW networks, making them more efficient and robust for practical applications in solar cells. The study comprehensively examines the optoelectronic properties of the ED AgNW networks, encompassing total and specular transmittance, transmission haze values, and sheet resistance, with varying durations of silver electrodeposition. Additionally, this study presents the current density (J)-voltage (V) characteristics of CIGS thin-film solar cells employing the ED AgNW TCEs, revealing how electrodeposition duration impacts overall device performance. These findings offer valuable insights for optimizing TCEs in not only thin-film solar cells but also in other optoelectronic devices, highlighting the potential for improved long-term stability across various applications without compromising performance.
        4,000원
        1390.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Following the attack on Israel by Hamas militants on October 7, 2023, Israel declared war on the Gaza Strip. In the relentless and nonstop bombardment of the Gaza Strip, about 40,000 Palestinian civilians have lost their lives, the majority of whom were children and women. Additionally, more than 92,000 Palestinians have been injured and many more are still missing or under the rubble. The dire situation in the Gaza Strip requires a firm stand from the international community, as what is happening to the Palestinian people is nothing short of genocide. This paper discusses Israel’s attacks on the Gaza Strip and illustrates how these actions meet the criteria for war crimes, crimes against humanity, and genocide. It also discusses the case filed by South Africa against Israel in the International Court of Justice, alleging that Israel has violated the Convention on the Prevention and Punishment of the Crime of Genocide.
        6,100원
        1391.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study emphasizes the vital role of local governments in Vietnam in advancing gender equality, particularly in achieving the UN Sustainable Development Goal (SDG) 5. It argues that local governance is crucial for translating national gender equality commitments into practical outcomes while simultaneously driving sustainable development. This article examines Vietnam’s legal frameworks, policies, and local governance practices to assess their effectiveness in promoting gender-responsive governance under the UN SDG framework. The author explores the relationship between local governance and gender equality, emphasizing the transformative impact of integrating gender perspectives at the local level. The findings demonstrate a strong link between effective local governance and progress toward SDG 5. She advocates for empowering local governments to implement gender-inclusive policies, which are essential for achieving gender equality and sustainable development in Vietnam. Furthermore, it provides strategic recommendations to strengthen gender responsiveness in local governance, contributing to the broader discourse on sustainable and inclusive development.
        5,500원
        1392.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research examines China’s development in terms of the nation’s SOE reforms surrounding the two major milestones in China’s integration with neoliberalism, the accession to the World Trade Organization and the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP). It considers the interlinking of the legal aspect of China’s SOEs reform with its economic development, and reinforces the economic argument that China has embraced both neoliberalism and state-capitalism in order to achieve its industrial development. This paper highlights the persistent logic of China’s SOEs reform which aims to approach international legal standards while keeping sight of the objectives of economic development. China’s semi-embrace of neoliberalism and its insistence on state capitalism, on the one hand, provide an alternative developmental model for other developing countries, while on the other hand, facing an increasingly deteriorating relationship with the US which cannot tolerate any rising power that challenges its hegemony, especially a power with a different ideology.
        6,100원
        1393.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Online infringement of Artificial intelligence (AI) generated content essentially constitutes IP infringement and should adhere to Article 50 of Law of the People’s Republic of China on the Law Applicable to Foreign-Related Civil Relationships. However, applying Article 50 to online infringement involving AI-generated objects presents a dual interpretation dilemma. The first dilemma pertains to the interpretation of the requested place of protection. The second issue concerns the redundancy of party autonomy in the article. Therefore, Article 50 should be reinterpreted with as emphasis on maintaining the territoriality of IP rights to make it applicable to online infringement of AI-generated objects. The place where protection is sought should be understood as the forum. If there are relevant factors, the affected cyberspace can be ‘collapsed’ into the court’s location. By employing the territoriality of IP, party autonomy should be limited to regulating the issue of damages.
        5,800원
        1394.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An appropriate strain of Bacillus spp. derived from traditional Korean fermented foods was selected for fermentation of black rice bran, and the fermented bran’s nutritional components were analyzed. Among 18 isolated Bacillus spp. strains, the five (KU3, KU24, KU28, KU611, and KU612) that exhibited both amylolytic and proteolytic activities were selected for fermentation. Among these, Bacillus sp. KU3 showed notable dual enzymatic activity. During fermentation in black rice bran medium, Bacillus sp. KU3 increased from 5.83 to 7.83 Log CFU/mL after 24 h. The KU3 strain was identified as Bacillus subtilis using an API 50 CHB kit and 16S rRNA sequencing. Black rice bran (4% w/v) was fermented with B. subtilis KU3 at 37°C, 150 rpm for 24 h. Following fermentation, the main component of the fermented black rice bran was carbohydrate (77.13%). An increase in ash content was observed, while other nutritional components showed no significant changes. These results suggest that B. subtilis KU3 is a viable strain for black rice bran fermentation.
        4,000원
        1395.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to broaden the utilization of rice flour by incorporating it into white bread. The rice flour used was derived from the "Baromi 2 (B2)" soft rice variety developed by the Rural Development Administration. Wheat flour in white bread was substitution with B2 at levels of 20%, 40%, 60%, 80%, and 100%. The physicochemical properties of the resulting products were evaluated. As B2 substitution levels increased, fermentation expansion and product volume decreased. However, no significant differences from the control group were observed substitution levels up to 20%. Increasing B2 levels also reduced the crust’s Browning Index (BI), whereas products with appropriate B2 substitution exhibited reduced staling rates. These findings suggest that B2 has the potential to be used as a wheat flour substitute at levels up to 20% in baked goods. This study also reaffirms B2’s suitability as an alternative to wheat flour, suggesting that incorporating various baking enzymes and gluten substitutes will improve the quality of rice-based bread products in future applications.
        4,000원
        1396.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        사막화는 기후변화로 인해 전 세계적으로 심화되고 있으며, 몽골도 이에 큰 영향을 받고 있다. 본 연구는 한국기독교환경운동연대(KCEMS)가 시작한 “은총의 숲” 프로젝트를 탐구함으로, 몽골의 사막화 문제를 다룬다. 30년에 걸친 이 프로젝트는 사막화 방지, 지속 가능한 창조 보전, 다차원적 인 이웃 사랑을 실천하는 한국교회의 생태적 선교 사례이다. KCEMS는 이 프로젝트를 지속적으로 추진하고 모니터링하며, 창조질서 보전 차원에 서 몽골 현지인들에게 실질적인 경제적 혜택을 제공함으로 몽골 현지인들의 참여를 촉진한다. 따라서 변혁적 제자도의 관점에서, 이 프로젝트는 기후변 화로 인해 영향을 받고 고통받는 이들과의 선교적 연대를 구현한다. 이를 통해 본 연구는 교회가 화해의 메시지를 전파하고, 생명죽임의 세력에는 저항하고 성령님과 연합하여 생명살림의 희망을 창조하도록 강조하며, 교회가 사랑과 정의의 복음을 선포하는 예언자적 사명으로서의 사역을 강화할 것을 촉구한다.
        7,000원
        1397.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A series of toxicity trials was conducted to analyze the acute and subchronic oral toxicity of calcium from Jeju Lava Seawater (CJLS) in Sprague-Dawley rats. In the acute toxicity trial, rats were administered 0 or a daily dose of 2,000 mg/kg body weight (BW) of CJLS. General behavior, side effects, and mortality were monitored over 14 days. In the subacute and subchronic trials, daily doses of 0, 250, 500, or 1,000 mg/kg BW were administered to the rats over 28 and 90 days, respectively. Clinical signs were examined daily, and changes in body weight, relative organ weight (ROW), and hematological, biochemical, and pathological parameters were recorded. The acute toxicity trial showed that the maximum tolerated dose of CJLS was >2,000 mg/kg BW, with no adverse effects or mortality observed during the 14-day period. In subacute and subchronic trials, oral administration of CJLS at a dosage of 1,000 mg/kg BW/day did not result in significant changes in BW, ROW, or hematological and biochemical biomarkers. These results indicate that the oral administration of CJLS at doses lower than 1,000 mg/kg BW/day is safe for rats, providing a basis for the clinical use of CJLS.
        4,000원
        1398.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examined the physicochemical and mechanical properties of edible composite films made of cellulose nanofiber (CNF) and shellac (Sh). All films were conditioned at 25℃ and 53% relative humidity (RH) for at least 48 h before analyses. Increasing the Sh ratio from 0% to 100% resulted in an increase in film thickness from 57.8 μm to 71.1 μm, while opacity decreased significantly from 22.3 mm⁻¹ to 3.7 mm⁻¹. With the increase in the Sh ratio, the moisture content, water solubility, and swelling of the film increased from 9.7% to 35.1%, 4.9% to 100%, and 3.0% to 10.5%, respectively. The CNF film (0% Sh) exhibited a lower water contact angle than the films with 80% and 100% Sh, but it was more water-resistant. As the Sh ratio increased, the tensile strength, yield stress, Young’s modulus, and work of break of the films decreased significantly from 17.9 MPa to 0.3 MPa, 1.00 MPa to 0.38 MPa, 220.7 MPa to 0.9 MPa, and 0.67 MJ/m3 to 0.13 MJ/m3, respectively. Conversely, the elongation at break increased dramatically from 10% to 253%. This study demonstrated that the thickness, opacity, moisture-related properties, and mechanical properties of CNF-Sh composite films could be tailored by varying the biopolymer ratio.
        4,000원
        1399.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국경 간 인수합병(Cross-border M&A)은 이중 조직 정체성과 다양한 제도적 환경을 관리하는 복잡한 통합 과제를 포함한다. 기존 연구들은 주로 국가 수준의 요인에 초점을 맞췄지만, 특히 자 회사의 경험과 같은 목표 기업의 특성에 대한 연구는 상대적으로 부족했다. 본 연구는 자회사 대 독립 기업, 국내 자회사 대 해외 자회사와 같은 다양한 목표 기업의 특성이 국경을 넘는 M&A에서 인수 기업의 주주 가치에 어떻게 영향을 미치는지 분석한다. 1994년부터 2012년까지의 국경을 넘 는 M&A 거래에 대한 이벤트 연구를 통해, 자회사의 경험이 인수 기업의 주주 가치를 증가시킨다 는 것을 발견했다. 그러나 제도적 거리가 증가할수록 국내 자회사의 경험 가치는 감소하는 경향이 있었다. 이러한 연구 결과는 국경을 넘는 M&A에서 자회사 경험의 중요성을 강조하며, 제도적 거 리가 그 효과를 어떻게 조절하는지를 보여준다. 이는 연구자와 실무자 모두에게 중요한 시사점을 제공한다.
        9,800원
        1400.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: In this qualitative descriptive study, we aimed to explore the experiences of nurses providing end-of-life (EOL) care in an emergency department (ED) setting and identify the associated challenges and implications for clinical practice. Methods: Twelve nurses with over 1 year of EOL care experience in the ED were interviewed. The collected data were analyzed using thematic analysis, as outlined by Braun and Clarke. Results: Five main themes with corresponding subthemes were identified: (1) Inadequate Environment for EOL Care, including physical environment barriers for a dignified death and emotional restraint in a chaotic setting; (2) Impact of Life-Sustaining Treatment Decision Complexity, encompassing complicated dynamics of family decision-making and compromised care quality in the decision-making process; (3) Managing Care Relationships in Physician-Limited Settings, manifested as navigating limited physician communication and bearing the emotional weight of EOL care; (4) Challenges in Protecting Patients’ Rights, characterized by powerlessness in the face of silent patients and confusion from reversed decisions by families; and (5) Actualizing Compassionate EOL Care, ensuring dignity through purposeful actions and navigating environmental barriers to dignified care. Conclusion: We highlight the need for systematic changes in the ED to better support EOL care, including the development of culturally sensitive communication protocols, shared guidelines for decision-making, and improved collaboration between healthcare professionals. These findings provide valuable insights into enhancing EOL care in EDs. Future efforts should focus on policy changes, tailored education programs, and support systems that address the multifaceted needs of patients, families, and healthcare providers.
        4,200원