Graphene shows unique electron-transport properties owing to the density of its carriers near the Dirac point. The quantum capacitance (CQ) of graphene is an intrinsic property that has been investigated theoretically in many previous studies. However, the development of CQ theory is hindered by the limited availability of related experimental works. In this perspective, experimental works on the CQ of mechanically exfoliated graphene, graphene synthesized by chemical vapor deposition (CVD), and graphene mesosponge are briefly summarized. The impact of structural properties such as stacking layers, defects, and nitrogen doping on CQ was experimentally investigated. Furthermore, the applicability of CQ theory was extended to three-dimensional graphene frameworks. Future research on CVD-synthesized and three-dimensional graphene is expected to enhance our comprehension of the underlying nature of CQ.

In this study, an attempt was made to approximate the main characteristic values of Bi0.5(Na0.78K0.22)0.5TiO3 (= BNKT) depending on the content of Fe2O3 additives, aiming to approach the values of lead(Pb) piezoelectric ceramic materials (PZT). Specifically, when the piezoelectric coefficient (d33) value of lead(Pb) piezoelectric ceramic material (PZT polycrystalline ceramic powder) is 300[pC/N] or higher, it is applied for hard purposes such as ultrasonic welding machines and cleaning machines, and when it exceeds 330[pC/N], it is applied for soft purposes like piezoelectric sensors. In this study, research and development were conducted for devices with a piezoelectric coefficient (d33) of 300[pC/N] or more for actuators. For this purpose, K+ exceeding 0.02 to 0.12 mol% was added to (Na0.78K0.22)0.5Bi0.5TiO3 to analyze structural changes due to K+ excess, and (Na0.78K0.22)0.5Bi0.5TiO3 + 8mol% K2CO3 Ti4+ was substituted with Fe3+ to manufacture lead-free piezoelectric materials. As a result, ceramics with Fe3+ substitution at x = 0.0075 yielded an average value of d33 = 315[pC/N]. Furthermore, for ceramics with Fe3+ substitution at x = 0.0075, the average values of maximum polarization (Pmax), residual polarization (Prem), and coercive field (Ec) were found to be 39.63 μC/cm2, 30.45 μC/cm2, and 2.50 kV/mm, respectively. The reliable characteristic values obtained from the research results can be applied to linear actuator components (such as the zoom function of mobile cameras, LDM for skin care, etc.) and ultrasonic vibration components.

This study aims to explore the development and current state of suppressor technology through a review of existing research and case studies, and to propose future directions for further research. Firstly, we analyze domestic and international research topics related to suppressors to determine emerging trends and research needs. Secondly, we investigate the reasons behind the discrepancies in noise reduction data from different studies that utilize identical measurement standards, proposing potential solutions to this issue. Furthermore, we examine key factors influencing suppressor performance, such as the design and shape of suppressors, including the effectiveness of baffle systems, pass-through suppressor technology, and fluid-filled suppressors. Additionally, we delve into the advancements in suppressor materials, assessing their durability, weight reduction, and thermal management capabilities, which are critical to the effectiveness and longevity of suppressors in modern warfare. This research contributes to the understanding of suppressor technology, highlighting the importance of design optimization and material innovation in enhancing both performance and practicality. The findings can guide the development of next-generation suppressors that meet the increasingly complex demands of contemporary combat environments.

PURPOSES : As evaluation methods for road paving materials become increasingly complex, there is a need for a method that combines computational science and informatics for new material development. This study aimed to develop a rational methodology for applying molecular dynamics and AI-based material development techniques to the development of additives for asphalt mixtures. METHODS : This study reviewed relevant literature to analyze various molecular models, evaluation methods, and metrics for asphalt binders. It examined the molecular structures and conditions required for calculations using molecular dynamics and evaluated methods for assessing the interactions between additives and asphalt binders, as well as properties such as the density, viscosity, and glass transition temperature. Key evaluation indicators included the concept and application of interaction energy, work of adhesion, cohesive energy density, solubility parameters, radial distribution function, energy barriers, elastic modulus, viscosity, and stress-strain curves. RESULTS : The study identified key factors and conditions for effectively evaluating the physical properties of asphalt binders and additives. It proposed selective application methods and ranges for the layer structure, temperature conditions, and evaluation metrics, considering the actual conditions in which asphalt binders were used. Additional elements and conditions considered in the literature may be further explored, considering the computational demands. CONCLUSIONS : This study devised a methodology for evaluating the physical properties of asphalt binders considering temperature and aging. It reviewed and selected useful indicators for assessing the interaction between asphalt binders, additives, and modified asphalt binders and aggregates under various environmental conditions. By applying the proposed methods and linking the results with informatics, the interaction between asphalt binders and additives could be efficiently evaluated, serving as a reliable method for new material development.

In this study, polyimide (PI)-based activated carbon fibers (ACFs) were prepared for application as electrode materials in electric double-layer capacitors by varying the steam activation time for the PI fiber prepared under identical cross-linking conditions. The surface morphology and microcrystal structural characteristics of the prepared PI-ACFs were observed by field-emission scanning electron microscopy and X-ray diffractometry, respectively. The textural properties (specific surface area, pore volume, and pore size distribution) of the ACFs were calculated using the Brunauer–Emmett–Teller, Barrett–Joyner–Halenda, and non-local density functional theory equations based on N2/ 77 K adsorption isotherm curve measurements. From the results, the specific surface area and total pore volume of PI-ACFs were determined to be 760–1550 m2/ g and 0.36–1.03 cm3/ g, respectively. It was confirmed that the specific surface area and total pore volume tended to continuously increase with the activation time. As for the electrochemical properties of PI-ACFs, the specific capacitance increased from 9.96 to 78.64 F/g owing to the developed specific surface area as the activation time increased.

The arrival of the 5G era has made electromagnetic pollution a problem that needs to be addressed, and flexible carbon-based materials have become a good choice. In this study, wet continuous papermaking technology was used to prepare carbon fiber paper (CFP) with a three-dimensional conductive skeleton network; Molybdenum disulfide ( MOS2)/ iron (Fe) @ carbon fiber paper-based shielding material was prepared by impregnating and blending molybdenum disulfide/iron ( MOS2/Fe) phenolic resin MOS2/ Fe@ CFP. The morphology, structure, electrical conductivity, mechanical properties, hydrophobicity, and electromagnetic shielding properties of the composite were characterized. The results show that the three-dimensional network structure based on a short carbon fiber paper-based conductive skeleton and the synergistic effect of the MOS2 dielectric wave absorbing agent and Fe magnetic wave absorbing agent have good electromagnetic shielding performance. Conduct electromagnetic shielding simulation using HFSS software to provide options for the structural design of CFP. The electromagnetic shielding performance of CFP reaches 70 dB, and the tensile strength reaches 34.39 MPa. Based on the mechanical properties, the compactness of carbon fiber paper is ensured. The lightning damage model test using CST software expands the direction for the use of carbon fiber paper. In summary, MOS2/ Fe @CFP with excellent shielding performance has great application prospects in thinner and lighter shielding materials, as well as high sensitivity, defense and military equipment.

Additive Manufacturing (AM) is a process that fabricates products by manufacturing materials according to a three-dimensional model. It has recently gained attention due to its environmental advantages, including reduced energy consumption and high material utilization rates. However, controlling defects such as melting issues and residual stress, which can occur during metal additive manufacturing, poses a challenge. The trial-and-error verification of these defects is both time-consuming and costly. Consequently, efforts have been made to develop phenomenological models that understand the influence of process variables on defects, and mechanical/ electrical/thermal properties of geometrically complex products. This paper introduces modeling techniques that can simulate the powder additive manufacturing process. The focus is on representative metal additive manufacturing processes such as Powder Bed Fusion (PBF), Direct Energy Deposition (DED), and Binder Jetting (BJ) method. To calculate thermal-stress history and the resulting deformations, modeling techniques based on Finite Element Method (FEM) are generally utilized. For simulating the movements and packing behavior of powders during powder classification, modeling techniques based on Discrete Element Method (DEM) are employed. Additionally, to simulate sintering and microstructural changes, techniques such as Monte Carlo (MC), Molecular Dynamics (MD), and Phase Field Modeling (PFM) are predominantly used.

In the history of Chinese academics, Xu Shen’s Shuowen Jiezi (hereinafter referred to as Shuowen) is known as “the first of its kind in the world” because it has the dual characteristics of explaining the form, sound, and meaning of Chinese characters and the characteristics of theoretical works on philology, both of which are practical. It has not only become a treasure of codex for the compilation of character books and exegesis, but also laid down the basic patterns of traditional philology and biblio-linguistics, with far-reaching influence. Many scholars have researched Shuowen in the past dynasties, resulting in the formation of an independent thematic discipline called Shuowen, also known as Xuxue (許學). According to Ding Fubao (丁福保), Shuowen jiezi Gulin (hereinafter referred to as Gulin) attached to the Yingyong Zhushu Xingshi Lu (引用諸書姓氏錄) statistics, there were as many as 203 people in the Qing Dynasty who studied and wrote Shuowen. In fact, there are many scholars and their achievements that are not included in the statistics. After Gulin, especially in the last 30 years, a lot of new materials of scholars in the Qing Dynasty who studied the Shuowen have been excavated and published. Most of these new materials are dispersed in their original state in different large series, so they are rarely researched and utilized, and their documentary and scholarly value is in urgent need of formal recognition. Based on the preliminary results of the major project of the National Social Science Foundation (21&ZD299) chaired by Li Yunfu (李運富), this article discusses the excavation, collation, and research of new materials on Shuowen in the Qing Dynasty.

본 연구는 기능성 화장품 소재로서 생태교란종으로 지정되어있는 가시박 (Sicyos angulatus L., SA)의 이용 가능성을 알아보기 위하여 항산화, 미백, 항균, 항염증 효능 평가를 수행한 후, 에멀션 안정성을 확인하였다. SA는 초순수 (SAW)와 70% EtOH (SAE)로 추출하였다. SAE는 SAW와 비교하 여 DPPH radical 및 ABTS+ radical에 대한 소거 활성과 SOD 유사 활성이 보여 항산화의 효능이 뛰어 나며, tyrosinase의 활성을 저해하여 멜라닌 생성을 억제하였다. SAW는 Escherichia coli (E.c), Staphylococcus epidermidis (S.e), Staphylococcus aureus (S.a), Pseudomonas aeruginosa (P.a), Cutibacterium acnes (C.a) 균주에 대한 항균 효과가 없는 반면, SAE는 S.a를 제외한 E.c, S.e, P.a, C.a 균주에서 clear zone이 생성되어 항균 활성을 나타내었다. LPS를 처리한 RAW 264.7 세포에서 SAE는 SAW보다 iNOS 및 COX-2의 발현량이 억제됨으로써 NO의 생성량을 억제하여 항염증에 대한 효능을 나타내었다. SAE을 첨가한 에멀션을 4℃, 25℃, 50℃의 온도에서 분리 현상이 관찰되지 않고, pH와 점 도는 수치상 큰 변화가 없었으며, 입자크기가 대조군 에멀션의 입자와 유사하므로 제형에 영향을 끼치지 않음을 확인하였다. 본 연구 결과를 기반으로, 기능성 화장품 연구에 새로운 소재로서의 활용 가능성을 제시하고자 한다.

본 논문은 최근 6년간(2018년~2023년) 한국의 주력 산업인 반도체, 디스플레이, 전 기·전자, 자동차 등 HS 6단위 기준 총 94개 품목을 대상으로 수출편향지수(EBI), 대 칭적 현시비교우위지수(RSCA), 불변시장점유율(CMS) 등 무역통계지표를 통해 한· 중 양국의 소재·부품·장비의 경쟁력과 수출증감요인을 분석하였다. 분석 결과, 반도 체 관련 품목의 대중국 수출편향이 증가한 반면 디스플레이 품목은 EBI 지수 감소 하고 있어 중국 내 품목으로 대체되고 있는 것으로 추정할 수 있었다. 또한 자동차 관련 품목의 EBI 지수가 전체 분석 기간 1 이하로 중국에 대한 수출집중도가 낮을 뿐 아니라 수입 편향에 있음을 확인할 수 있었다. 대칭적 현시비교우위지수(RSCA) 분석에서 품목별 차이는 있지만 전기·전자 품목은 세계시장에서 상대적으로 낮은 경 쟁력을 보유하고 있었다. 반면 반도체, 디스플레이 및 자동차 관련 품목은 일부 품목 을 제외하고 중국과 비교하여 비교우위를 나타내고 있었다. 불변시장점유율(CMS) 분석에서 기준년도(2018년) 대비 비교연도(2023년)의 한국의 대중국 감소 요인이 수 입규모요인보다 경쟁력요인과 수입구조요인이 더 큰 영향을 미치는 것으로 분석되었 다. 이는 한국의 소재·부품·장비 관련 품목의 경쟁력 감소와 일본 등 제3국의 경쟁력 상승으로 인해 한국의 대중국 수출 감소를 가져온 것으로 추정되었다.

The objective of this study is to examine ways to develop and design actual teaching and learning materials based on grammar consciousness-raising tasks. In our country, unlike in the field of English or Korean language education as a foreign language, in the area of Spanish education there is very little research on grammar consciousness-raising tasks and there is no research on the development of teaching and learning materials. Therefore, this study was focused on teaching Spanish as a foreign language. First of all, we looked at the concept and characteristics of the grammar consciousness-raising tasks, their pros and cons, and the expected effects of introducing these tasks into domestic Spanish education. Afterwards, we set the teaching and learning model based on the grammar consciousness-raising tasks and looked at things to be careful about when designing tasks corresponding to each stage. Based on this, we created actual teaching and learning materials. We hope that this study will serve as a reference and that research on grammar consciousness-raising tasks will be actively conducted in domestic Spanish education, and that materials will be developed with more diverse language items. El objetivo de este estudio es examinar formas de desarrollar materiales de enseñanza y aprendizaje basados en las tareas gramaticales y diseñar materiales reales. En nuestro país, a diferencia de la enseñanza del idioma inglés o coreano como lengua extranjera, existe muy poca investigación sobre las tareas gramaticales en el ámbito de la enseñanza de la lengua española, y no existe investigación sobre el desarrollo de materiales de enseñanza y aprendizaje. Por ello, este estudio se centró en la enseñanza del español como lengua extranjera. En primer lugar, analizamos el concepto y las características de las tareas gramaticales, sus ventajas y desventajas, y los efectos esperados al introducir estas tareas en la educación del español en el país. Posteriormente, configuramos el modelo de enseñanza y aprendizaje basado en las tareas gramaticales y analizamos los aspectos a tener en cuenta a la hora de diseñar las tareas correspondientes a cada etapa. Con base en esto, creamos materiales de enseñanza y aprendizaje reales. Esperamos que este estudio sirva como referencia y que se lleven a cabo activamente investigaciones sobre las tareas gramaticales en la educación del español en nuestro país, y que se desarrollen materiales con elementos lingüísticos más diversos.