Korea is a major chestnut producer, and about half of its production is discarded as chestnut shells. This study aimed to manufacture an environmentally friendly adsorbent using these wastes. For this purpose, the optimum carbonization temperature of chestnut shells was derived through thermogravimetric analysis, with structural change confirmed through SEM analysis. The results showed that the sample that carbonized at 350oC for 60 min after phosphorylation had both the highest initial acetaldehyde removal rate and the longest duration compared to other samples. As a result, an eco-friendly adsorbent for acetaldehyde was produced from chestnut shell biomass. Through this research, it was confirmed that the adsorbent can be effectively used for acetaldehyde control while addressing the issue of recycling chestnut shell wastes.

지금 우리의 시대를 지칭하는 용어로 얼마 전까지 사용하던 4차산업혁명시 대보다 ‘AI 시대’가 더 적합한 것으로 보인다. 4차산업혁명의 기술적 변화 가 운데 가장 직접적이고 가시적으로 그 변화를 체감하게 하기 때문이다. 이전에 도 기존의 기보(棋譜)를 암기, 학습하던 수준에서 스스로의 수(手)를 찾아낸 AlphaGo처럼, 특정 분야에서의 활용 위주로 설계된 AI들도 상당한 능력을 보여준 바 있다. 하지만 이렇게 특정 분야에 특화된 것이 아니라, 다양한 목 적에 적용될 수 있는 범용인공지능이 그 학습속도와 역량이 역시 비약적으로 발전되어 스스로 질문하고 답하는 단계에 이른다면 그 영향력은 무엇을 상상 하든 그 이상이 될 것이다. 물론 GPT, 라마(LLaMA) 등 범용인공지능의 능 력이 개발사 혹은 그 추종자들이 홍보, 찬양하고 있는 것만큼 발전되어 있는 가에 대한 의문도 있다. 또한 기술적 진보를 중시하고 그에 의한 부작용 역시 기술적으로 극복가능할 것이라고 보는 낙관론자와 달리 기술적 진보가 가져 올 부작용을 두려워하는 비관론자 혹은 그 과도기적 상황에서 나타날 문제를 더 크게 보는 사람도 있다. 그리고 부인하기 힘든 것은 우리가 가진 미래에 대한 인상은 앞선 시대에 예술적 천재들이 미리 엿보고 와서 그려낸 기술적 dystopia가 그려진 영화, 드라마, 소설의 영향에서 자유롭지 못하다는 점이 다. 지금의 기술적 진보수준을 정확하게 평가하기 어렵고, 그 미래는 더더욱 예측하기 힘든 나의 입장에서 더 크게 보이는 것은 기술적 진보가 해결해줄 문제들보다 기술적 진보가 초래하는 새로운 문제들이다. AI와 관련된 문제는 앞으로도 오랫동안 우리 시대의 화두가 될 것으로 보 인다. 그러나 적어도 지금의 단계에서 AI는 막연한 두려움이나 기대의 후광 으로 인해 그 정확한 실체를 알아보기 힘들다. 또한 하루가 다르게 발전하는 관련 기술의 진보에 따라 오늘의 논의는 내일의 문제를 해결하기 위해서 무 용(無用)해지기 십상이다. 지나친 공포로 인해 관련기술의 발전을 억제하는 것도, 막연한 낙관으로 인해 우리가 통제할 수 없는 괴물을 우리 손으로 창조하 는 것도 경계할 필요가 있을 것이다. 다만 지금의 수준에서는 AI의 도구적 성격에 주목하여 그 유용성을 활용하면서도 부작용 혹은 그 가능성을 억제, 감시할 수 있어야 하고, 이러한 노력은 국가 단위를 넘어서 범지구적으로도 협력할 필요가 있을 것으로 보인다.

Purpose: This study aimed to understand the meaning and essence of college life experiences of mature-aged male nursing students. Methods: Data were collected between November 2024 and December 2024 through in-depth, face-to-face interviews with ten older male nursing students. Data were analyzed using Colaizzi’s seven-step phenomenological analysis method. Results: The results comprised four theme clusters and 17 themes. Participants experienced “A tough start,” “Multidimensional obstacles,” “Source of strength,” and “Turning point in life.” Participants entered nursing school after overcoming challenging entrance exams in pursuit of stable employment during periods of economic instability and job scarcity. Additionally, they encountered dual barriers, both in terms of age and gender over the study period. They struggled because of their financial instability, academic stress, conflicts in social relationships, and insufficient university support services. However, despite these hardships, they persisted in their academic journey, encouraged by the joy of learning, with informal social support from family and friends and determined to complete their college courses. Ultimately, they perceived college life as a transformative phase through positive change, growth, and professional development in their journey toward becoming nurses. Conclusion: It is necessary to identify the individual needs of older male nursing students and provide university support services from a gender-equity perspective.

This study evaluated changes in volatile organic compounds (VOCs) and aerosol particle concentrations following the use of certain spray-type household chemical products in an indoor environment. Four commercially available products in South Korea (including sticker/tar removers, a razor cleaner, and a fabric stain remover) were analyzed using real-time VOC monitoring with proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) and particle number concentration measurement with an Optical Particle Sizer. Immediately after spraying 17 grams of each product, VOC concentrations increased sharply, and hazardous substances such as benzene, 1,3-butadiene, formaldehyde, and acrolein remained at elevated levels for a certain period. Additionally, some products exhibited benzene concentrations exceeding levels of potential exposure concern, and the operation of an air purifier reduced VOC levels by 73%. This research provides insight into changes in indoor air quality and associated exposure risks due to household chemical use, and it may serve as a basis for future air quality management and regulatory standards.

This study investigated the correlation between compound malodor and total hydrocarbons (THC) to evaluate the potential use of THC as a predictor of compound malodor. A total of 87 samples were analyzed from five target facilities: two petrochemical manufacturing facilities (A, B), a wastewater treatment facility (C), a recycled plastic injection molding facility (D), and a surfactant manufacturing facility (E). The correlation coefficients of compound malodor and THC for each facility were as follows: A: 0.6698, B: 0.8068, C: –0.2767, D: 0.2071, and E: 0.7695. The correlation coefficient for all facilities was 0.5634, indicating a weak correlation. The coefficients of determination for the regression analysis to predict the compound malodor for facilities A, B, and E were 0.4093, 0.6316, and 0.5695, respectively, which validated the results of the correlation analysis. These values improved to 0.8394, 0.6941, and 0.7476 in the multiple regression analysis with the VOC analysis results added as independent variables. Therefore, it is expected that THC measurement that considers the characteristics of the facility can be used to establish a systematic odor management plan.

Purpose: This study was aimed to explore and analyze the experiences of nurses regarding department transfers following the sudden closure of a ward due to the collective resignation of residents. Methods: Data were collected from November 1 to 29, 2024, and a qualitative content analysis was employed. The participants were 11 nurses who were transferred to different departments following a ward’s sudden closure owing to the residents’ collective resignation. Results: A total of six themes and 24 sub-themes were identified. the first theme is ‘After the resident left, the ward was closed’. The second theme is ‘Various job placements were assigned after the ward’s unfortunate closure’. The third theme is ‘Difficulty adjusting to the new environment and leaning to adapt’. The fourth theme is ‘Changes in the nurse-physician relationships’, and the subtheme is ‘Surprised by doctors seeking nurses' opinions due to the absence of residents. The fifth theme is ‘Become an expert at adapting’. The sixth theme is ‘Worries about the future and a faint glimmer of hope’. Conclusion: This study highlights the challenges nurses encountered in adjusting to new departments following the unprecedented mass resignation of residents and the ensuing ward closure. Nurses initially faced difficulties, feeling expendable in the new environment. However, through the support and collaboration of their colleagues, they demonstrated resilience and adapted effectively. The study also noted that, despite the absence of residents, direct communication between medical staff and patients continued to function smoothly, facilitating their involvement in treatment planning alongside specialists and professors. Although departmental transfers can lead to increased job stress for nurses, successful adaptation during these transitions fosters professional growth by enhancing their knowledge, skills, and influence. Furthermore, knowledge sharing among nursing staff contributes to the overall development of the organization. To promote both personal growth and organizational advancement, nursing managers must actively listen to nurses’ perspectives about departmental transfers and provide compassionate support to assist in their adaptation. Creating an organizational culture that recognizes and values the contributions of colleagues who have undergone transfers is essential. By establishing a systematic approach that facilitates successful adaptation and fostering a positive, accepting nursing culture, departmental transfers can be transformed into an effective strategy for enhancing the professionalism and capabilities of nursing staff.

Objectives: This study aimed to evaluate the environmental awareness and health impact of respiratory diseases among residents in the exposure area (Banwoldong) and the control area. Additionally, it sought to identify the correlation between environmental factors in the exposure area and their effects on health. Methods: This study utilized a 2021 survey of 20 residents to assess environmental awareness using a 5-point Likert scale. The measurement of indoor particulate matter (PM10, PM2.5), temperature, and humidity was conducted using a direct-reading laser light scattering device, the DT-9881M (SANE Cal. Co., Ltd., Korea). Additionally, a cohort analysis was conducted using National Health Insurance Service (NHIS) data (2002~2022) to evaluate the onset of chronic disease, focusing on residency and diagnostic records. Results: In the environmental awareness assessment, women showed a statistically significantly higher level of awareness than men regarding water pollution (p=0.0039) and soil pollution (p=0.007). Also, the incidence of respiratory diseases and asthma was statistically significantly higher in the exposure area than in the control area (p<0.0001). Conclusion: This study found significantly higher rates of respiratory diseases in the exposure area compared to the control area. Long-term exposure (≥5 years) to environmental factors in the exposure area was found to be associated with a greater health impact. This suggests a strong link between environmental factors and respiratory diseases. The results emphasize the need for region-specific environmental policies to address pollution-related health disparities.

2024년 12월 3일 위헌적인 공권력행사인 비상계엄 선포로 촉발된 헌법적 비상사태 하에서 제기되었던 다양한 헌법적 쟁점 중에서 ① 현행 헌법 아래 에서 계엄포고령에 언론·출판·집회·결사에 대한 검열제와 허가제를 규정할 수 있는지 문제, ② 권한대행에 대하여 탄핵소추를 할 때 의결정족수는 어떻게 되는지, 헌법과 법률에서 탄핵소추 대상자로 명시되지 아니한 자를 탄핵소추 할 수 있는지 그리고 권한대행에 대하여 탄핵인용 결정이 선고될 경우 권한 대행직 뿐만 아니라 본래의 지위에서도 파면되는지의 문제, ③ 현행 헌법과 형사소송법 체계 아래에서 내란죄의 수사 주체 논란과 압수수색영장의 집행 에서 실효성의 문제를 면밀하게 분석하였다. 분석한 결과물을 정리하면 다음 과 같다. 첫째, 현행 제6공화국 헌법은 표현의 자유와 관련하여 제21조 제1항에서 언론ㆍ출판의 자유와 집회ㆍ결사의 자유를 보장하면서 제2항에서 언론ㆍ출판 에 대한 허가나 검열과 집회ㆍ결사에 대한 허가는 인정되지 아니함을 규정함 으로써 표현의 자유에 대한 허가나 검열을 절대적으로 금지하고 있다. 현행 헌법의 이와 같은 규정 태도로 인하여 현행 헌법 아래에서 비상계엄이 적법 하게 선포되고 이에 수반하여 계엄포고령이 발령되더라도 계엄포고령에서 언 론ㆍ출판에 대한 허가나 검열과 집회ㆍ결사에 대한 허가를 규정하는 것은 위 헌이다. 둘째, 국무총리가 대통령 권한대행으로서 직무집행과정에서 위헌·위법행위 를 한 경우 국회가 대통령 권한대행인 국무총리에 대한 탄핵소추를 의결하려 면 대통령 탄핵소추 의결정족수인 재적 3분의 2 이상의 찬성을 요한다고 해 석하여야 한다. 또한 헌법과 법률에서 탄핵소추 대상자로 규정되지 아니한 자 가 탄핵소추 대상자의 권한대행으로 직무수행 과정에서 위헌·위법행위를 한 경우에도 국회는 탄핵소추를 의결할 수 있다고 보아야 한다. 한편, 권한대행 에 대한 탄핵심판에서 헌법재판소가 인용결정을 선고할 경우 권한대행의 직은 물론이거니와 본래의 지위에서도 파면된다고 해석하는 것이 헌법의 취지 에 부합한다. 셋째, 현직 대통령의 내란 행위에 대하여 고위공직자범죄수사처가 내란죄의 수사 주체로 되는 것이 적절한지 여부와는 별개로, 현행 법률의 해석상 고위 공직자범죄수사처의 현직 대통령 내란 혐의 수사에 법적 문제점은 없다고 보 아야 한다. 입법 정책적으로는 내란죄의 수사 주체는 검찰청법상의 검사가 되 는 것이 효율적이고 적절하므로 검사가 직접 수사할 수 있는 범죄에 내란죄 를 포함하도록 검찰청법을 개정할 필요가 있다. 한편, 현직 대통령의 내란 범 죄 수사와 관련하여 구체적 판단을 거쳐 법관이 발부한 압수수색영장이 형사 소송법 제110조 때문에 영장 집행이 사실상 불가능한 상황이 발생할 수 있 다. 형사소송법 제110조는 사실상 내란죄의 증거 확보와 보전을 어렵게 하여 내란죄 수사를 난관에 부딪히게 할 수 있으므로 내란죄에서는 형법 제110조 적용을 배제하거나 영장을 발부하는 법관에게 형사소송법 제110조를 배제할 수 있는 권한을 부여하는 등의 입법적 개선이 필요하다.

This study investigates and analyzes the major characteristics of naturally occurring asbestos (NOA) in the Seosan area, based on a geological map of NOA distribution. The study area includes Daesan-eup, Seokmun-myeon, and Palbongmyeon in Seosan-si, Chungcheongnam-do, South Korea, with 32 samples collected from nine sites. The asbestos-containing rocks primarily consist of dolomite, limestone, calcareous silicate rock, and marble, most of which exhibit a mass-fiber morphology. While the weathering grade of the outcrops is generally within level 3, some areas show higher weathering levels (grade 4), indicating potential risks of asbestos dispersion into the air. The collected samples were analyzed using polarized light microscopy (PLM), X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and transmission electron microscopy with energy-dispersive spectroscopy (TEM-EDS). The primary asbestos types identified were tremolite and actinolite asbestos of the amphibole group, with anthophyllite asbestos detected in some locations. Notably, certain asbestos-containing rocks were found near coastal areas and docks, highlighting the need for continued monitoring in the event of future development activities.

Purpose: This study explored emergency nurses’ perception of and experiences with infection control in the emergency department (ED). Methods: This qualitative study employed focus group interviews and conventional content analysis. The participants were 19 nurses working in the ED of three general hospitals in the metropolitan area, and the data collection period was from July 1, 2024, to August 30, 2024. Four focus group interviews were conducted with each group consisting of 4~5 participants. Interviews were conducted for approximately 80 minutes per group. The interviews were audio-recorded and transcribed verbatim immediately afterward. Data were analyzed using conventional content analysis. Results: A total of 167 meaningful statements were extracted from the interviews. Five main themes and 15 subthemes were identified through interview analysis. 1) Limited information with “Limited information at the entrance of the ED” and “Challenges in sharing information”; 2) The gap between guidelines and reality with “Difficulty in adhering to guidelines due to a shortage of isolation rooms”, “Underestimating protective isolation”, “Skepticism due to practical limitations” and, “The need for infection control guidelines to fit ED circumstances”; 3) Application of guidelines that deviated from the principles with “Different nursing practice based on visual judgment”, “Guidelines that were overlooked in emergency situations” and, “Justifying the avoidance of tedious work by claiming to help prevent infection”; 4) Insensitivity to infection with “Performing only pretended infection control”, “Overlooking the importance of protective equipment”, and “Being became insensitive to infection”; and 5) The need to strengthen the organizational culture of infection control with “Interpreting the same guideline differently by individuals”, “The need for support from senior nurses to comply with the guidelines”, and “The need for practical training that reflects the reality of the ED”. Conclusion: ED nurses faced challenges in complying with infection control guidelines in the ED. These challenges were attributed to a combination of physical, structural, and personal factors. A unique feature of this study is its emphasis on the organizational culture of infection control. To improve compliance with infection control guidelines among emergency nurses, it is imperative to improve their physical and structural environment and provide regular practical training. This approach aims to foster an organizational culture that places a strong emphasis on infection control.

Composites of carbon fiber-reinforced silicon carbide (Cf/SiC) with ultra-high temperature ceramics (UHTCs) exhibit superior resistance to oxidation and ablation under high temperatures. Components in large-scale applications often have complex geometries, making it crucial to understand the oxidation and ablation behaviors of curved and non-uniform surfaces. In this study, a Cf/SiC-ZrB2 composite was fabricated into a 300 mm cylindrical shape using filament winding and liquid silicon infiltration processes. The resulting specimens exhibited a uniform microstructure, with SiC and ZrB2 crystals evenly distributed across the top and bottom surfaces, demonstrating the feasibility of producing large-scale composites. The specimens underwent an oxyacetylene torch test at 2,100 K for 5 min to assess their ablation and oxidation performance. The results revealed significant variation in the oxide layer due to the non-flat surface, with the layer thickness gradually decreasing as the oblique angle was reduced. Additionally, the presence of high-melting-point ZrO2 in the oxide layer near the torch center was attributed to the migration and solidification of molten SiO2. This suggests that large and complex Cf/SiC incorporating UHTCs can effectively form a protective oxide layer, even under conditions where SiO2 displacement occurs. The findings underscore the importance of integrating geometric considerations into the design of ultra-high temperature ceramic composites to achieve the thermal and ablation resistance required for advanced high-temperature applications.

We investigated the effect of band gap engineering on the thermoelectric properties of n-type Cu0.008Bi2Te3 using the two-band (TB) model. The experimental measurements showed a zT of ~0.41 at 300 K and ~0.46 at 520 K, with an optical band gap of ~0.13 eV. While fixing the density-of-state effective mass (md *), deformation potential (Edef), lattice thermal conductivity (κl), and Fermi level based fitted based on experimental data, we varied the band gap (Eg) from 0.1 to 0.3 eV to analyze its impact on the thermoelectric performance. The TB model calculations revealed that the power factor (PF) increased and the thermal conductivity (κ) decreased with increasing Eg at both 300 K and 520 K, leading to an enhancement in zT. The magnitude of this enhancement was more pronounced at 520 K than at 300 K, which can be attributed to the suppressed bipolar effects at higher temperatures. Our findings suggest that increasing the band gap of Cu0.008Bi2Te3 can significantly improve its thermoelectric performance, to an estimated maximum zT of ~0.61 at 520 K for Eg = 0.3 eV. The theoretical maximum zT, considering the optimized hole concentration (nH), was estimated to be ~0.75. We demonstrate that Eg engineering of narrowbandgap semiconductor thermoelectric materials can significantly enhance thermoelectric performance.

Zinc tin oxide (ZTO) thin films were deposited using atomic layer deposition (ALD) to ensure precise thickness control and uniformity. However, the low-temperature processing of ZTO often results in increased defect states, leading to degraded electrical performance. To address this issue, metal capping layers (Al or Au) were added to the ZTO active layer. The capping layers modulate electron energy levels at the interface, increase carrier density, and reduce interface traps, thereby improving electrical properties. Aluminum (Al) and gold (Au) were evaluated for their impact on key performance metrics, including electron mobility (μsat), threshold voltage (VT), subthreshold swing (SS), and on/off current ratio (ION/OFF). Results show that Al-capped ZTO thin-film transistors (TFTs) exhibited enhanced performance due to the lower work function of Al (4.0 eV), which facilitates electron injection and reduces contact resistance. In contrast, Au-capped ZTO TFTs showed decreased performance due to electron depletion caused by the higher work function of Au (5.1 eV). Optical analyses, including UPS and UV-Vis, revealed the band structure and work function of the ZTO thin films. This study concludes that the choice of capping material and its design parameters play a critical role in optimizing TFT performance, offering valuable insights for the development of next-generation high performance TFT devices.

This study examines the volatilization of alkali elements on the surfaces of ceramic targets and in the deposited films during the deposition of potassium sodium niobate (KNN) thin films using a ceramic target with the nominal composition K0.55Na0.55NbO3 via a RF magnetron sputtering process. Under a 100 W RF power condition, significant volatilization of alkali elements occurred on the surface of the ceramic target, resulting in the inevitable formation of a Nb-rich secondary phase in the thin films. However, perovskite-phase KNN thin films with excellent reproducibility and without secondary phases were obtained under 50 W RF power and a substrate temperature of 600 °C. When the RF power was reduced to 20 W or the substrate temperature was lowered to 500 °C under 50 W RF power, no crystalline thin films could be obtained. Additionally, when the substrate temperature was raised to 700 °C under 50 W RF power, the niobium-rich secondary phase appeared in the thin films due to the volatilization of alkali elements. The conditions of 50 W RF power and a substrate temperature of 600 °C were found to be optimal for depositing perovskite-phase KNN thin films. However, complete suppression of potassium volatilization from the thin films was not achievable. Consequently, the resulting films had a sodium-rich composition compared to K0.5Na0.5NbO3 and exhibited lower dielectric constants along with relaxor ferroelectric characteristics. This study highlights the importance of monitoring the compositional changes in ceramic targets during the RF sputtering process to ensure high reproducibility in KNN thin film fabrication.

This study investigated the process of reclaiming Mo from calcined waste hydrotreating (CWHT) catalysts using tributyl phosphate (TBP) as an extractant with electron-withdrawing properties. Using inductively coupled plasma (ICP) technology, the optimal operating conditions for Mo recovery were determined based on the metal ion content in different processes. Considering the pH impact on metal species in solution, an acid leaching solution with 6 M sulfuric acid was employed. After 3 h of reaction, 94 wt% of the Mo was transferred from the WHT catalyst to the acid leaching solution. Adjusting the filtrate to a pH of 1.5 allowed the TBP to selectively extract over 98.8 wt% of Mo from the aqueous filter solution into the organic phase. MC-Cabe-Thiele theory predicts that a three-stage countercurrent extraction can reduce Mo to less than 0.2 wt%. Stripping moved approximately 98 wt% of the Mo from the organic to the inorganic phases. The recovered colorless organic tributyl phosphate can be used in the recycled extraction process.

X-ray diffraction is widely used as a non-destructive method for measuring residual stress in crystalline materials, and is particularly useful as a technique for controlling residual stress that has been introduced during the heat treatment or surface treatment of metallic materials. Neutron stress measurement is gaining attention as an internal material measurement method. It complements the demerits of the X-ray method in that it measures stress in a very thin surface layer. The neutron stress measurement method, like the X-ray method, is based on the principle of crystal diffraction, and its penetration depth is about 1,000 times greater than that of the X-ray method and is suitable for measuring the inside of a material. This study investigated the residual stress measurement method using the sin2ψ method using shot-peened mechanical structural carbon steel. The non-destructive measurement using high-energy X-rays was compared with the residual stress measured using conventional laboratory X-rays, and the following results were obtained. The high intensity diffraction angles using highenergy X-rays are low, but can be measured with sufficient precision. Interpreting the three diffractions 633, 552, and 721 as a single diffraction profile allowed stress measurements to be made, and the calculated value was close to the weighted average of the intensity ratios. The results of the high-energy X-ray residual stress measurements were in good agreement with the results from laboratory X-rays, confirming the usefulness of this method as a non-destructive method of assessing stress deep inside materials.

With increasing globalization and the urgent need for sustainable energy solutions, electrochemical water splitting has emerged as a crucial technology for clean energy production. In this study, we report the successful synthesis of 0.1 % Fe-doped NiS2 via a one-step hydrothermal method. The incorporation of Fe into the NiS2 matrix significantly enhances its electrochemical performance, as evidenced by a remarkable reduction in overpotential, to 180 mV at a current density of 10 mA cm-2, compared to 250 mV for undoped NiS2. Additionally, the Fe-doped NiS2 exhibits a reduced Tafel slope, high double layer capacitance, and lower charge transfer resistance than undoped NiS2, indicating improved reaction kinetics for oxygen evolution. These improvements are attributed to the enhanced conductivity and catalytic activity imparted by Fe doping, which facilitates more efficient charge transfer and reaction processes at the electrode surface. The results suggest that Fe-doped NiS2 is a highly promising and robust candidate for applications in electrochemical energy conversion. Moreover, the doping strategy employed here offers a valuable approach for tailoring the properties of other metal sulfides and chalcogenides, paving the way for the design of next generation electrocatalysts that can drive large-scale energy conversion processes with minimal energy loss.

A cold roll-bonding (CRB) process is applied to fabricate an AA1050/AA5052 layered sheet. In the process, commercial AA1050 and AA5052 sheets of 1 mm thickness, 40 mm width and 300 mm length are stacked onto each other, and then reduced to a thickness of 0.5 mm through a 2-pass cold rolling process without lubricant. The roll-bonded AA1050/AA5052 layered sheet is then annealed for 1 h at various temperatures from 200 to 400 °C. The specimens annealed at temperatures below 250 °C showed a typical deformation structure in which the grains were elongated along the rolling direction. However, the specimens annealed at temperatures higher than 300 °C exhibited recrystallization structures in both the AA1050 and AA5052 regions. All the roll-bonded and subsequently annealed specimens showed an inhomogeneous distribution of hardness in the thickness direction, in which the hardness in the AA5052 regions was higher than that in the AA1050 regions. As the annealing temperature increased, the tensile and yield strengths decreased and the elongation increased gradually. The mechanical properties were compared to those of commercial AA1050 and AA5052 materials and CRBed AA5052-2L materials from a previous study.

Lithium-ion batteries (LIBs) are widely used as essential power sources for electric vehicles and energy storage systems. Among various cathode materials, Li[Ni0.9Mn0.1]O2 (NM90) has gained significant attention for enhancing the performance of LIBs due to its high energy density and nontoxicity. However, increasing the nickel content introduces challenges, including structural instability and cation mixing. To address these issues, we propose a surface coating strategy using nitrogendoped carbon quantum dots (NCQDs). NCQDs provide high electrical conductivity and electrochemically active sites, so the NCQDs coating effectively enhanced both structural stability and electrical/ionic conductivity. The NCQDs were synthesized via a hydrothermal method, and NM90 were synthesized by co-precipitation. The fabricated NCQD/NM_5 electrode exhibited superior electrochemical properties, including a high initial capacity of 189.6 mAh/g, excellent rate performance, and an outstanding capacity retention of 81.5 % after 200 cycles in 1C. These superior results demonstrate that surface modification using the NCQDs strategy for Li[Ni0.9Mn0.1]O2 cathode materials will contribute to the further development of cycle stability and ultrafast performance in energy storage systems.

Humans have the ability to perceive an object’s material and properties instantaneously, and use this information to prepare for future actions. Material perception is not only an important factor for humans but also for artificial intelligence robots that are being developed. In addition, material perception is one of the important design requirements in selecting materials suitable for the products desired by consumers and pursued by designers. Because it is impossible to perform material perception using an exact formula, it is determined from tendencies that are identified in surveys. In this study, surveys with a binary selection were conducted, presenting participants with pairs of bipolar adjectives and asking them to choose one of two. After multiple surveys were conducted all the data were merged. Before merging the data, to ensure the reliability of the data homogeneity and correlation were tested using hierarchical clustering, correlation coefficient, and k-means cluster analysis. Afterwards, the merged data was used to analyze universal and comparable perceptual qualities of various material classes using relative frequency and hierarchical cluster analysis.