In this study, freeze-dried red beet powder was characterized for its physicochemical properties and functional components and subsequently incorporated into rice cookies at levels of 0%, 2%, 4%, 6%, and 8% to assess its effects on quality characteristics and antioxidant activity. As the level of red beet powder increased, moisture content decreased, whereas both the diameter and thickness of the rice cookies increased, resulting in a reduced spread ratio. In terms of color parameters, lightness and yellowness decreased, whereas redness significantly increased with increasing red beet powder content, indicating a distinct visual change in the cookies. Antioxidant activity increased proportionally with red beet powder levels. These findings demonstrate that incorporating red beet powder effectively enhances the antioxidant activity and functional properties of rice cookies.
In situations where materials are rare difficult to obtain, the ability to test small specimens is becoming increasingly important, particularly for aerospace. In the nuclear power generation field, tensile and small punch testing of small specimens is being utilized to evaluate integrity. In this study, we designed and validated small specimens suitable for aircraft engine components. A fixture for small plate specimens was optimized using finite element analysis to ensure uniform stress distribution, and the specimens were manufactured through precision machining. Tensile tests and creep rupture tests were conducted, and the results were analyzed and compared with those from round specimens made from the same alloy. The yield strength and tensile strength of the small plate specimens were within 5 % of the round specimens, but there was less elongation compared to the round specimens. The difference in the decrease in elongation of the round specimens and small plate specimens was analyzed using the Voce equation to identify the cause. The approach used in this study enables the evaluation of the mechanical properties of engine components with limited material options or those in operation, and is expected to be utilized for monitoring the condition of critical components.
A new oak mushroom cultivar Lentinula edodes ‘Eomjisong’ (LE23734), was developed by crossing the dikaryotic and monokaryotic strains of ‘KME36298’ and ‘KME36288-1’, respectively. The optimal temperature for mycelial growth of ‘Eomjisong’ on potato dextrose agar was 23–27°C, and was 15–20°C for fruiting body development. The cultivation period of ‘Eomjisong’ was 131 days, which was 3 days shorter than that of the control cultivar ‘Hanacham’. Morphologically, ‘Eomjisong’ showed stipe length and thickness similar to those of ‘Hanacham’, however, the pileus was larger and thicker. Furthermore, the pileus of ‘Eomjisong’ exhibited higher brightness than that of ‘Hanacham’. Productivity tests showed that the total yield of ‘Eomjisong’ reached 555 g, which was approximately 25.6% higher than that of ‘Hanacham’ (442 g). These findings indicate that ‘Eomjisong’ is a promising cultivar with enhanced productivity and morphological advantages over ‘Hanacham’, suggesting its potential for commercial cultivation.
The present study introduces a machine learning approach for designing new aluminum alloys tailored for directed energy deposition additive manufacturing, achieving an optimal balance between hardness and conductivity. Utilizing a comprehensive database of powder compositions, process parameters, and material properties, predictive models—including an artificial neural network and a gradient boosting regression model, were developed. Additionally, a variational autoencoder was employed to model input data distributions and generate novel process data for aluminum-based powders. The similarity between the generated data and the experimental data was evaluated using K-nearest neighbor classification and t-distributed stochastic neighbor embedding, with accuracy and the F1-score as metrics. The results demonstrated a close alignment, with nearly 90% accuracy, in numerical metrics and data distribution patterns. This work highlights the potential of machine learning to extend beyond multi-property prediction, enabling the generation of innovative process data for material design.
This study addresses the increasing damage to national heritage due to climate change by analyzing the current use of terms that describe deterioration damage phenomena in wooden architectural heritage, and proposes a framework for defining and systematizing these terms. The research found that inconsistencies in the use of terms for the same deterioration damage phenomena and unclear definitions in regular heritage survey and monitoring reports cause confusion in data analysis and accumulation. Consequently, this study followed ISO 704 and KS standards to understand the relational system of terms, proposing a hierarchical structure with "deterioration damage" as the top concept and systematically organizing its sub-concepts. Specific terms such as "crack," and the Korean-originated terms "Gallem" and "Apgoe", were analyzed to establish clear definitions and build a system based on their conceptual properties. The study is expected to enhance the effectiveness of heritage conservation and management, ensure consistency in terminology usage among researchers, and support the establishment of data-based scientific conservation policies. Future research will focus on developing practical standardization strategies for deterioration damage terminology through in-depth discussions with field experts and conducting long-term national-level studies.
이 연구는 북한에서 개혁개방이 일어날 가능성과, 개혁개방이 발생하 면 어떤 형태를 띨 것인지에 대하여 분석한다. 김정은 집권 이후를 연 구범위로 설정하고, 북한을 둘러싼 국제정치, 북한 주민의 아래로부터 의 개혁, 그리고 고위 엘리트층의 변혁이라는 세 가지 측면에서 가능성 을 예측한다. 주요 결론은 국제정치와 북한 주민의 관점에서 점진적 개 혁개방의 가능성이 현저히 낮으며, 엘리트 내부 균열에 의한 우발적 체 제 변화 가능성이 가장 높다는 것이다. 이 연구를 통해 대한민국과 국 제사회의 대북정책 방향 설정에 함의를 제공하고, 구체적으로 한국의 정책적 대응 전략을 제시하며, 통일과 안보 의제에 실질적인 분석을 제 공한다.
일반적인 택코트용 유화아스팔트는 도로 포장면에 살포되고 양생되는 과정에서 공사차량 및 포설장비 타이어에 쉽게 들 러붙어서 포장면의 코팅막 훼손과 같은 심각한 문제를 일으킬 뿐 아니라, 접착력과 전단강도가 약하여 상하 포장층간 부 착력 저하로 균열, 포트홀, 밀림과 같은 포장도로 조기 파손의 주요 원인이 되고 있다. 본 연구에서는 택코트 시공 후 양생시간을 현저히 단축시키고 공사차량 통행에 의한 접착 처리면 훼손을 최소화하여 아스팔트 포장의 조기 파손을 방지할 뿐 아니라, 포장체의 장기 공용성능을 크게 향상시키는 초속경성 타이어 미부착 택코트 유화아스팔트 개발과 이를 고속도로 현장에서 적용한 사례에 대해 소개하고자 한다. 해당 기술은 택코트 훼손방지 기능 외에도 폴리머가 함유된 아스팔트를 적용하여 부착강도가 매우 우수하며, 배수성 포장, SMA 포장, 교면 포장 등 특수포장의 공용성 증진효과가 큰 것으로 나타났다. 양생시간 또한 크게 단축되어 1액형 택코트의 경우 30분 이내에 양생이 되며, 양생 촉진제를 적용하는 2액형 택코트는 5분 내에 양생을 완료 시킬수 있어서, 시공시간 단축을 통한 조기 교통개방을 가능하게 한다. 해당 기술은 국토교통부 개질 유화아스팔트 품질기준인 RS(C)-PG70T 규격을 만족하였고, 타이어 부착률이 약 1.5% 대로 우수한 것으로 나타났다. 고속도로 현장 적용성 평가 결과, 양생시간이 5분 이내로 확인되었으며, 시공 후 현장 코어 시편 확인 결과, 택코트층이 잘 보전되어 있었으며, 포장층간의 결합력이 우수하게 유지되었다. 따라서 고속도로 뿐만 아니라 서울시와 같은 도심지 및 택코트의 충분한 양생시간을 확보하기 어려운 아스팔트 유지보수 공사에 본 기술을 적용하는 것은 매우 효과적일 것으로 판단된다.
Hair dyeing, hair perming, and daily hair dryer use can substantially damage hair. Consequently, the demand for products containing natural ingredients for the care of damaged hair is growing. Although polyphenols with antioxidant effects are often used for hair conditioning, few studies have focused on hair conditioning, and the potential of Sparassis latifolia mushroom extract for hair improvement has not been evaluated to date. In this study, the antioxidant activity of and polyphenol content in hot water, 70% and 100% ethanol (EtOH), n-hexane, ethyl acetate (EtOAc), and water extracts of S. latifolia were analyzed. A hair treatment containing S. latifolia extract was prepared, and its effect on damaged hair was evaluated. The highest antioxidant activity was observed in the hot water and EtOAc extracts. Moreover, polyphenol analysis using high-performance liquid chromatography and liquid chromatography-mass spectroscopy confirmed that the EtOAc fraction has relatively high contents of specific polyphenols beneficial for hair. Based on these results, a hair treatment containing S. latifolia extract was applied to damaged hair, and hair improvement was evaluated using hair thickness, tensile strength, and scanning electron microscopy. The hair treatment containing 70% EtOH extract effectively improved hair condition. We postulate that this improvement was caused by the high hydrophobic polyphenol content in the 70% EtOH extract.
이 연구는 한국 초등교원양성기관의 실습학기제 도입에 따른 운영방안 을 탐색하고자 하는 데 목적이 있다. 이를 위하여 한국 초등교원양성기 관의 교수들 중 교육실습 경험이 풍부한 교수 2명, 교육과정 담당자 2 명, 실습학교 교사 5명을 대상으로 FGI(Focus Group Interview)를 실 시하여 질적 연구를 수행하였다. 연구 결과, 한국 초등교원양성기관의 실 습학기제 운영에 대한 5개의 영역과 그에 대한 17개의 범주, 그리고 65개의 하위 범주가 도출되었다. 한국 초등교원양성기관의 실습학기제 운영에 대한 5개의 영역은 ‘현 체제 진단’, ‘실습학기제에 대한 인식’, ‘현실적인 문제’, ‘운영을 위해 필요한 것’, ‘운영방안’이다. 그리고 각 영 역별 논의를 통해 한국 초등교원양성기관의 실습학기제 운영방안에 대한 시사점을 제공하였다.
This study explored the process-structure-property (PSP) relationships in Ti-6Al-4V alloys fabricated through direct energy deposition (DED) additive manufacturing. A systematic investigation was conducted to clarify how process variables—specifically, manipulating the cooling rate and energy input by adjusting the laser power and scan speed during the DED process—influenced the phase fractions, pore structures, and the resultant mechanical properties of the samples under various processing conditions. Significant links were found between the controlled process parameters and the structural and mechanical characteristics of the produced alloys. The findings of this research provide foundational knowledge that will drive the development of more effective and precise control strategies in additive manufacturing, thereby improving the performance and reliability of produced materials. This, in turn, promises to make significant contributions to both the advancement of additive manufacturing technologies and their applications in critical sectors.