In this study, a thermal-fluid-structure coupled analysis was performed to improve the thermal performance of a burner for a coal gasification power plant. After combustion analysis, an average temperature of 1,400°C was obtained, closely matching the actual coal gasification system environment. The highest burner tip surface temperature, 887°C, was achieved at the analysis variable, a coal fines inflow velocity of 8m/s. This temperature was mapped to a thermal-structural analysis model, and by increasing the radius of the cooling channel inside the burner to 5 mm, the analysis confirmed a reduction in thermal stress of approximately 20%. In particular, changing the material to HP50-Nb resulted in significantly superior cooling efficiency compared to Inconel 718 without any cooling channel design. The results of this study will be useful for the optimal design of coal gasification facilities as well as for improving the durability of the facilities.

흙생강은 태국의 생강과(Zingiberaceae)에 속하는 식물로 의약품, 식품등의 소재로 활용되고 있 다. 이에 본 연구에서는 화장품 소재로 활용하기 위해 흙생강의 열수 추출물을 제조하고 항산화, 항염, 및 보습 효능을 확인하였다. 흙생강 열수 추출물의 총 폴리페놀 함량을 확인한 결과 약 163.69 ± 0.90 mg TAE/100 g의 함량을 보유하였으며 라디칼 소거능을 확인한 결과 ABTS 라디칼 소거활성이 우수함을 확인 하였다. 세포독성이 없는 농도에서 NO 생성 저해 활성을 확인한 결과 농도의존적으로 저해 효능이 나타났 다. 또한, 피부 보습 활성을 확인하고자 HA 생성량을 확인한 결과 10 μg/mL의 농도에서 기존 각질형성 세포보다 약 29.47%의 증가를 관찰하였다. 결론적으로 흙생강 열수 추출물은 화장품 소재로 항염 및 보습 효능을 나타내며 기능성 화장품 소재로 활용 가능성을 확인하였다.

본 연구는 선박용 내연 기관에 적용되는 연료 분사 노즐을 대상으로, 수소 연료 운전 조건에서의 구조적 거동을 규명하기 위해 정적 열-구조 연성(static thermo-structural coupled) 유한요소 해석(FEA)을 수행하였다. 해석은 상용 프로그램 ANSYS Mechanical 2025 R1을 사 용하였으며, 주요 경계 조건으로 연료 공급 온도 -60°C~120°C, 연료 공급 압력 60 bar 및 연료 분사 압력 60 bar를 적용하였다. 또한 노즐 니들의 개폐(open/close) 상태를 각각 모델링하여 니들의 개폐에 따른 구조적 응답 변화를 비교하였다. 해석 결과, 노즐의 최대 등가 응력 (maximum equivalent stress)은 니들 폐쇄 상태에서 니들 개방 상태에 비해 약 1.6배 높게 나타났으며, 최대 등가 응력은 모든 조건에서 유로 벽면에 집중되었다. 이러한 결과는 수소 연료 적용 시 노즐의 잠재적 취약 부를 사전에 예측할 수 있음을 시사하며, 내수소성 확보를 위 한 재료 선정 및 구조 보강 설계의 기초 자료로 활용될 수 있다. 제안된 해석 접근법은 향후 수소 내연기관용 노즐의 내구성 향상, 형상 최적화 및 신뢰성 평가를 위한 기반 연구로서 의의가 있다.

본 연구에서는 용융염 원자로(MSR)의 열 전달 성능을 최적화하기 위한 수학적 모델을 제안하였다. MSRE 설계 개념을 기반 으로 한 제시된 모델을 통해 차폐 구조물에서의 열 손실을 계산하고, 다양한 변수들이 표면 온도 및 전체 열 성능에 미치는 영향을 평가하였다. SPROULE WR-1200과 같은 칼슘 실리케이트 기반의 단열재를 사용하였으며, 스틸볼 영역은 스틸볼과 물이 채워져 있고, 단열재와 스틸볼 영역 간격(Gap)이 있다고 가정하였다. 분석 결과, 단열재 두께, 간격 크기, 스틸볼 영역의 두께와 같은 변수들이 열 손실 및 표면 온도에 영향을 미친다는 점을 확인할 수 있었다. 특히, 단열재 두께 최적화를 통해 차폐 구조물의 열 효율성과 안전성을 크게 향상시킬 수 있음을 보여주었다. 본 연구는 차세대 원자로 시스템의 개발을 위한 차폐 구조물의 개념설계에 필요한 기초 자료를 제공한다.

This study investigates the thermodynamic processes of reduction for iron, manganese, silicon, aluminum, magnesium, and calcium within a blast furnace. We analyzed two primary mechanisms, indirect and direct reduction, to determine the conditions under which these elements are converted from their oxides into metallic form. For indirect reduction, driven by gas-solid reactions with carbon monoxide, calculations show that iron is effectively reduced at temperatures above 967 K and a carbon monoxide partial pressure greater than 0.575. However, other elements like manganese, silicon, aluminum, magnesium, and calcium require extremely high temperatures and carbon monoxide partial pressures approaching 1.0. This makes their indirect reduction in a typical blast furnace environment highly improbable. In contrast, direct reduction involves solid carbon (coke) directly reducing the oxides. Our analysis reveals that iron can be reduced at temperatures above 1000 K, which is well within the blast furnace's operating range. Manganese and silicon can also be produced through this direct reduction pathway at the high temperatures found in the furnace's lower zone, above 1691 K and 1952 K, respectively. However, aluminum, magnesium, and calcium require significantly higher temperatures that fall outside the normal operating conditions of the blast furnace. In conclusion, iron is effectively produced by both indirect and direct reduction mechanisms. While manganese and silicon are difficult to reduce indirectly, they are successfully produced through direct reduction in the high-temperature zone. Aluminum, magnesium, and calcium, on the other hand, are not produced in a blast furnace because their reduction temperatures are too high. This explains why only specific elements are reduced and incorporated into the final pig iron product.

In this study, the heat transfer characteristics of a liquid hydrogen (LH2) tank with multilayer insulation (MLI) were numerically investigated. The temperature distribution inside the LH2 tank and within the MLI, as well as the temperature variation according to positional changes, heat transfer rate, and boil-off rate (BOR), were compared and analyzed. The results showed a distinct stepwise temperature drop in Case 4 with 20 MLI layers and Case 8 with 40 MLI layers, where the insulation thickness was greatest. Under the same number of layers, the temperature gradient became more gradual as the MLI thickness increased. In addition, the temperature variation in the tank head region indicated that increasing the number of MLI radiation layers reduced the radiative heat flux, resulting in a gentler temperature variation and a longer temperature drop range. Furthermore, the analysis of heat transfer and BOR showed that both rates decreased under the condition with the greatest MLI thickness and number of layers, demonstrating the best insulation performance. In particular, under the same 40-layer condition, the BOR value of Case 8 was more than three times lower than that of Case 5, indicating a significant improvement in thermal insulation efficiency.

This study investigates the flow resistance and heat transfer characteristics of a fin-and-tube heat exchanger, applied to a water-cooled thermal management system designed for a cabinet-mounted high-performance computer operating aboard naval vessels. The analysis was conducted through both experimental and numerical approaches, focusing on the evaluation of heat transfer performance (j factor) and flow resistance (f factor) under varying air flow rates, while maintaining a fixed fin geometry and arrangement. Particular emphasis was placed on assessing the variation of the j factor along the total length of the heat exchanger to understand the impact of exchanger length on thermal performance. In the numerical analysis, instead of modeling the entire heat exchanger, a representative repeated unit composed of a single fin and twelve connected tubes was simulated. The outlet temperature from each tube segment was sequentially used as the inlet condition for the subsequent segment. This methodology significantly enhances computational efficiency while providing reliable predictions of progressive thermal characteristics along the flow path.

본 연구는 AI-Hub 한국어–중국어 구어체 병렬 말뭉치를 기반으로 중국어 촉각어 ‘热’의 한국어 의미 확장을 개념적 은유･환유 관점에서 분석하였다. ‘热’는 물리적 온 도 의미를 넘어 정서, 사회적 반응, 분위기 등 다양한 추상적 개념으로 확장되었으며, 이 과정에서 VITALITY IS HEAT, EMOTION IS HEAT 등 은유 구조와 환유･은 환유가 복합적으로 작동하였다. 중-한 비교에서는 직접 대응, 문화적 조정, 구조적 전환의 세 층위가 나타나 두 언어의 개념화 방식과 문화적 차이를 보여주었다. 본 연구는 구어체 자료를 통한 실증 분석으로 기존 문어 중심 감각어 연구의 한계를 보 완하고, 언어 간 개념 체계 비교의 방법론적 가능성을 제시하였다.

With the increasing number of aging buildings, the importance of structural safety inspections has grown significantly. Traditional methods for inspecting welding defects, such as visual inspection and magnetic testing, rely heavily on human expertise, making them time-consuming, costly, and subjective. To address these limitations, thermographic technology has been introduced as a non-contact alternative, significantly reducing both time and cost. Furthermore, by incorporating AI, an objective and automated evaluation of welding defects can be achieved. In this study, we propose an AI-based thermographic approach for detecting welding defects. To validate the applicability of this method, a Mock-up Test was conducted. Specifically, 12 types of welding specimens with 4 welding part were prepared, generating a dataset of 6,500 thermographic images. Among 7 regression algorithms tested, RF and EXT were selected due to their superior performance. By ensemble learning these two models, we developed a robust welding defect measurement algorithm. To further verify its effectiveness, we applied the developed algorithm to 2 real projects, evaluating its applicability using 450 thermographic images. The results of this study demonstrate the feasibility of AI and thermographic technology in welding defect detection, highlighting its potential to enhance the efficiency and reliability of structural safety inspections in aging infrastructures.

The thermal management of high-density electronics within military shelters is a critical challenge for ensuring operational reliability, particularly under harsh field conditions involving significant solar radiation. This study presents a numerical investigation using three-dimensional Computational Fluid Dynamics (CFD) to optimize an air-cooling system for an electronics rack housed in a military shelter. Four distinct cooling configurations were analyzed and compared: (1) a baseline model relying on natural convection, (2) a fan-assisted forced convection model, (3) a direct cold air supply model using an insulated duct, and (4) a hybrid model integrating both fans and the duct. Boundary conditions were established based on the high temperature and solar radiation criteria of the MIL-STD-810G standard. To quantitatively evaluate the cooling efficiency of each system, a normalized performance index derived from a weighted sum of the average temperature and temperature standard deviation was employed. The results demonstrate that the baseline configuration leads to critical overheating, with component temperatures reaching up to 124℃. In contrast, the hybrid fan-duct system exhibited the most superior performance, effectively reducing the maximum temperature to 59℃. This is attributed to a powerful synergistic effect, where the qualitative supply of low-temperature air via the duct is combined with the quantitative distribution of flow rate throughout the system by the fans. This study elucidates an effective thermal management strategy for electronics in military shelters exposed to severe environments, identifying the integrated fan-duct system as the most robust and optimal air-cooling solution.

This study developed a coupled fluid-thermal analysis method for a liquid hydrogen control valve system. Using ANSYS CFX, a transient CFD analysis was performed for the control valve system, including MLI, and the thermal analysis was linked to evaluate the insulation performance of MLI. The analysis examined the pressure distribution, turbulent viscosity, and heat flux at the inlet and outlet, revealing that the highest heat flux occurred in MLI 2. This research is expected to contribute to improving the thermal shielding performance and efficient insulation design of liquid hydrogen storage systems.

Co-Cr alloys are widely used in cutting tools and turbine components due to their high strength and resistance against wear and corrosion. However, scrap generated during hardfacing is often discarded due to impurities and oxidation, and research on its recycling remains limited. This study aimed to optimize the recycling process of Stellite 6 scrap to reduce waste and minimize costs while maintaining material quality. Melting, casting, and powdering processes were designed using HSC Chemistry, FactSage, and COMSOL Multiphysics, with optimization of key parameters such as the crucible material and temperature control. The recycled alloy and powder were analyzed using X-ray fluorescence analysis, inductively coupled plasma optical emission spectroscopy, and X-ray diffractometry, showing mechanical and chemical properties comparable to commercial Stellite 6. The Co and Cr contents were maintained, with a slight increase in Fe. These findings demonstrate the potential for producing high-quality recycled Stellite 6 materials, contributing to the sustainable utilization of metal resources in high-performance applications.

Since the small screen must be watched at the production and manufacturing site, when using the monitor without a separate paper for work and production instructions, it is necessary to look at the work instruction screen installed in a separate space to prevent work efficiency from deteriorating. It plays a role through a monitoring system using DPS or Barcode and RF-ID recognition as a safety device for installing heterogeneous parts in manufacturing and missing parts, but due to the high cost of introducing the system and difficulty in maintaining management, Visual POP is put into the production line. This study was produced by paying attention to the following five points in order to reduce the weight of these industrial Visual POPs and have global specifications and uses. These include instrument design and design, processing production, UI and control, application, thermal stress analysis and thermal analysis. In this study, it is considered to thermal stress analysis and thermal analysis of Visual POP for Models 1 and 2.

This study numerically investigated thermal-structural characteristics of a liquefied hydrogen (LH) storage cylinder with varying inner pressures and surrounding temperatures. A thermal-structure coupled analysis approach was used to predict the thermal-structural characteristics of the LH storage cylinder. For the simulation, the shape of the LH storage cylinder was simplified using SUS 316L and Carbon Fiber Reinforced Plastic (CFRP) materials. As a result, the inner pressure was a crucial factor determining the structural property (i.e., stress and deformation) of the LH storage cylinder. The high pressure led to increased stress and deformation. Additionally, the surrounding temperature affected the stress and deformation of the LH storage cylinder. For example, at a high surrounding temperature, the temperature gradient along the cylinder increased, thereby causing the occurrence of thermal stress. However, this temperature effect on the stress was negligible compared to the effect of inner pressure. The findings of this study will provide meaningful data for improving the structural safety of LH storage systems.