The mixed-ion electron conductor, Ag₂Se, has shown strong potential as a thermoelectric material operating near room temperature. In this study, we demonstrate that the incorporation of polyaniline (PANI) into Ag₂Se forms Ag₂Se/PANI nanocomposites with significantly enhanced thermoelectric performances. Ag₂Se was synthesized using a hydrothermal method followed by hot pressing to obtain dense composite pellets. The novelty of this work lies in the systematic tuning of the PANI content and its dual role in enhancing electrical transport while suppressing lattice thermal conductivity. Microstructural analysis reveals that PANI-induced defects, such as dislocations and point defects, effectively scatter phonons at multiple scales, resulting in a remarkably low lattice thermal conductivity (κₗ ≈ 0.08 Wm⁻1 K⁻1) at 393 K. Simultaneously, PANI improves carrier mobility by modifying the Coulomb potential at grain boundaries, reducing interfacial energy barriers. These effects lead to an improved power factor of 2028 μWm⁻1 K⁻2 and a peak figure of merit (zT ≈ 0.67) at 393 K for the 0.5 wt% PANI sample. This study introduces a novel polymer-assisted interface engineering approach to improve the thermoelectric performance of Ag₂Se-based materials.

본 연구에서는 최근 국내 절화 시장에서 증가하는 소형·특이 화형 수요와 생산 현장의 노동력 절감 요구에 대응하여 개발된 소형 겹꽃 절화용 거베라 신품종 ‘페더핑크(Feather Pink)’의 육성 경위와 주요 특성을 보고하고자 한다. ‘페더핑크’는 2011 년 초세가 강건한 ‘08B3-3’ 계통을 모본으로, 화색과 화형이 우수한 ‘07B3-14’ 계통을 부본으로 교배한 실생 집단에서 선발되었다. 2011년 교배 후 조직배양을 이용한 계대 증식과 2012- 2020년 연차별 생육 및 절화 특성 평가를 통해 유전적 안정성과 균일성을 확보하였다. 주요 특성으로 두상화 직경은 평균 7.5cm이며, 절화장은 56.2cm로 유통에 적합하였고, 연간 채 화량은 75.3본/주/년으로 안정적인 생산성을 보였다. 절화수명 은 8.7일로 상업적 활용에 충분하였으며, 소형 계열이라 꽃목 처짐이 없어 철심 삽입·테이핑·캡 씌우기 등 꽃목보강작업이 필요하지 않아 재배 및 취급 과정의 노동력 절감에 유리하였다. 또한 기호도 평가에서 화색, 화형, 균형미 등에서 높은 선호도를 나타냈다. 이러한 특성으로 ‘페더핑크’는 최근 확대되고 있는 소형 절화 시장의 소비 경향에 부합하며, 국내 절화 시장의 품종 다양성 확대와 농가의 재배 효율성 향상에 기여할 것으로 기대 된다.

This study was conducted to examine the structural stability of a lightweight structure for a sliding-type battery rack system located under an electric bus. To address the shortcomings of the existing sliding battery rack systems, the battery rack system was designed by applying lightweight materials and utilizing a bolt-mounting connection type. Finite Element Method(FEM)-based structural analysis was performed, considering both the system’s self-weight and the weight of the installed batteries. The analysis identified the maximum stress value and its location within the entire system. Furthermore, considering the different materials used in various components, the maximum stress values for each component were individually derived. By comparing the maximum stress with the yield strength of each material, it was confirmed that the designed lightweight battery rack system had secured structural stability.

This pilot study aimed to develop a novel type of functional dietary management food for individuals with diabetes, utilizing a soup and bread format, and to evaluate its postprandial glycemic response and consumer acceptability. Two types of soup and bread meals—tomato vegetable soup and curry chicken soup—were formulated using chickpeas and low-fat meat and were compared with a commercially available diabetic management meal. In a randomized crossover design, 15 participants consumed one of three meals (experimental or commercial diabetic meal) on separate days. Blood glucose levels were measured at 0, 30, 60, and 120 minutes post-meal. Experimental meals showed stable glycemic responses evidenced by decreased Area Under the Curve (AUC) (Tomato 12839.0±1432.8, Curry 12683.0±1408.4) compared to commercial meals (15485.0±1870.5, p<0.05). Sensory evaluation revealed moderate acceptability, and subjective hunger, satiety, and food cravings were also assessed, but showed no significant differences among three types of meal. Although limited by the small sample size and short intervention duration, these findings provide preliminary evidence supporting the feasibility of tailored meal solutions for metabolic conditions. Further large-scale, long-term studies are warranted to validate these outcomes and optimize product development for diverse populations.

In this study, a new Lattice integrated Rib-Type Deck Plate system is proposed to enhance the flexural stiffness and strength. This system integrated a rib-type corrugated deck with a steel wire lattice designed for short spans, which is placed on top of the corrugated deck. To validate the flexural performance of the proposed system, experimental programs were conducted for both the construction stage and the composite stage. Construction stage test results showed that all specimens exhibited deflections less than 13mm under the construction load, satisfying the maximum deflection limit of 19mm. Composite stage test results indicated that increasing the amount of tension and compression reinforcement led to improvements in initial stiffness, yield strength, and maximum strength. Furthermore, specimens with reinforcement in the compression zone demonstrated superior ductility. The flexural strength of all tested specimens was confirmed to be safely evaluated by the flexural strength equation specified in the Korea Design Standard.

본 연구는 남성 육아휴직의 활용이 조직몰입에 미치는 영향을 탐색하고, 이 과정에서 조직문화의 매개 역할과 기업유형(대기업, 중견기업, 중소기업, 공공기관)의 조절역할을 분석하기 위한 질적 사례연구이다. 최근 육아에 대한 남성의 참여가 증가함에 따라 기업의 내부제도 및 문화가 구성원의 조직몰입과 조직성 과에 어떤 영향을 미치는지에 대한 이론적, 실무적 관심이 높아지고 있다. 본 연구는 대기업, 중견기업, 중소기업, 공공기관에 재직 중인 남성 직원(사용자) 및 관리자 총 12명을 심층 인터뷰를 진행하여 육아휴 직 활용 경험과 조직문화 인식, 조직에 대한 몰입 수준을 중심으로 분석을 진행하였다. 연구의 결과로는 조직의 유연성, 상향식 소통 문화, 육아휴직에 대한 상사·동료의 지지의 조직문화가 조직몰입에 긍정적 영향을 미치는 것으로 나타났다. 또한, 기업의 유형에 따라 조직문화 인식과 몰입에 차이가 있었으며, 공 공기관과 대기업에서는 제도적 보장성의 활용이 높았고, 실질적 활용이나 문화적 수용에서 일부 제한점 이 존재하는 것을 확인하였다. 중견기업과 중소기업은 제도적 보장성은 낮고, 실질적 활용과 문화적 수용 에서도 낮은 편으로 확인되었다. 그리고 육아휴직 이후에는 육아휴직 남성 사용자의 조직몰입이 향상되 는 현상을 확인하였다. 따라서 본 연구는 남성 육아휴직 제도의 실효성 제고를 위한 조직문화 개선과 기 업유형에 따른 맞춤형 정책 필요성을 제시한다는 점에서 학문적 및 실무적 의의를 지닌다. 그리고 남성 육아휴직의 실질적인 활용은 일·가정 양립제도의 발전에 큰 기여를 가지고 올 수 있으므로 기업과 가정을 넘어 인구감소로 여러 가지 정책을 추진하는 국가 및 지방자치단체의 발전 요인으로도 충분히 활용될 수 있다.

Doping diamond exhibits excellent photoelectric properties, making it promising for applications in wide-bandgap semiconductors, high-temperature devices, and high-power electronics. However, research on n-type doping remains limited. This paper reviews the main n-type doping methods for diamond: ion implantation (I/I), chemical vapor deposition (CVD), high pressure–high temperature (HPHT), deuterated method (DM), surface charge transfer doping (SCTD), and laser irradiation (LI). It analyzes the parameters, advantages, and disadvantages of each technique while classifying common single-element and multi-element co-doping methods. Single-element dopants include Group IA (Li, Na, K), Group ⅡA (Be, Mg), Group VA (N, P, As, Sb), and Group ⅥA (O, S, Se, Te) elements. Multi-element co-doping often combines B-P, B-S, B-O, and B-N pairs. Additionally, we examine the atomic structures of these dopants, introduce commonly used simulation models, and compare the electronic characteristics of synthesized n-type doping diamonds. Finally, we summarize the challenges of n-type doping diamond in doping equipment, processes, and electronic devices, and propose possible improvements and future development directions.

The 30mm wheel type anti-aircraft gun replaces the aging anti-aircraft gun in the front and is a weapon system for local anti-aircraft defense against enemy aircraft and small unmanned vehicles. In the field, damage to the turret hatch/closed hatch pin occurred between the operation of the wheel type anti-aircraft gun. As a result of the sem analysis of the hatch pin fracture surface, it appears that brittleness fracture occurred and fatigue fracture occurred at the final fracture surface while reaching the fatigue strength by repetitive loads. The hatch angle fixing pin and bracket shapes were changed to disperse the stress concentration. As a result of checking the location of the vulnerable area of the hatch pin and the shear stress value through structural analysis, the safety factor improved from 1.46 to 2.95 after improvement. Through this study, it is expected to be used as a reference material for failure analysis and design plan for the existing system in the future.

Effective stress management in pilots is crucial for flight safety. This study assesses the stress levels of student pilots enrolled in a private pilot course during their initial flights by measuring heart rate variability (HRV) using a wrist watch type heart rate monitoring device. HRV data were collected from 31 student pilots across their first ten flight sessions. Statistical analysis using repeated measures ANOVA revealed that the highest stress levels occurred during the first flight and gradually decreased over subsequent flights. These findings highlight the need for flight instructors to provide supportive guidance during initial flights to help students adapt to flight conditions with minimized stress. Furthermore, the private pilot course curriculum may require revision to incorporate stress management and flight aptitude evaluation. This research contributes important insights into monitoring physiological stress responses in trainee pilots and informs strategies to enhance pilot training effectiveness and safety.

This study investigates nozzle diameter and fuel type effects on combustion characteristics and NOx emissions in radiant tube heating systems through numerical simulation. Four fuels were analyzed: LPG, natural gas, coke oven gas, and hydrogen under varying nozzle conditions using computational fluid dynamics with energy conservation, species transport, and thermal NOx formation models. Results show that nozzle diameter optimization significantly enhances internal recirculation, improving fuel-air mixing and reducing NOx formation. Hydrogen exhibits higher flame temperatures, potentially increasing thermal NOx generation, but optimal nozzle design controls this effect through enhanced mixing patterns. The optimized configuration achieved substantial NOx reduction while maintaining combustion stability across all tested fuels.

Active electronically scanned array (AESA) multi-function radars (MFRs) comprise numerous transmit/receive modules (TRMs) whose maximum temperature and temperature uniformity must be tightly controlled. This study proposes a new liquid-cooling-plate flow-channel design for an X-band AESA MFR: a two-layer straight channel incorporating multiple fins irregularly spaced along the flow channel. The proposed design (Type-4) is compared with three baseline channel designs. At the same coolant flow rate, Type-4 reduces the TRM maximum temperature by 28.2 K and the maximum inter-module temperature difference by 19.7 K relative to Type-1. However, the pressure drop increases by 726% because of the added internal surfaces and fins which are flow obstructions. A comprehensive thermo-hydraulic comparison, including pumping power criteria, is conducted over multiple flow-rate conditions. Overall performance was highest for Type-4, followed by Type-2, Type-3, and Type-1. When designs achieve similar maximum temperature and temperature difference with various coolant flowrate condition, Type-2 requires 83.6% less pumping power than Type-1, and Type-4 requires 33.8% less pumping power than Type-2.

513 magnesium hydroxide sulfate hydrate (MHSH) and Mg(OH)₂ were synthesized by controlling the pH and concentration using a domestic resource, dolomite (CaMg(CO3)2), as the raw material. The MgSO₄ was extracted by treating dolomite with sulfuric acid under various conditions. Hexagonal plate-shaped Mg(OH)₂ and needle-like 513 MHSH were synthesized under the hydrothermal condition. The morphology of the synthesized materials was controlled by adjusting the pH (SO42-/OH- ratio) and hydrothermal reaction time. As the pH of the solution increased, the formation of plate-like structures became dominant, whereas lower pH values (higher SO42- concentration) led to needle-like forms. The results of the 513 MHSH, which was synthesized using reagents and sea bittern, are consistent with the synthesis conditions, and we observed changes in the length and aspect ratio of the needle-shaped structure in response to adjusting the hydrothermal reaction time.

This study compared food security and dietary quality, as assessed by the Korean Healthy Eating Index (KHEI), between single-person and multi-person households among Korean adults using data from the Korea National Health and Nutrition Examination Survey (KNHANES). A cross-sectional analysis was conducted using the KNHANES data. The participants were categorized into single-person and multi-person households based on the household composition. Food security was assessed using a validated questionnaire that categorized households into food-secure, mildly food-insecure, and moderateto- severe food-insecure groups. The dietary quality was evaluated using the KHEI, Nutrient Adequacy Ratio (NAR), and Mean Adequacy Ratio (MAR). The final analysis included 13,647 adults aged 19–64 years. Among them, 1,176 (8.6%) were single-person households, while 12,471 (91.4%) were multi-person households. Single-person households showed a significantly higher prevalence of moderate and severe food insecurity than multi-person households (5.7% vs. 1.8%). The KHEI scores were significantly lower in single-person households (57.5±0.6) than in multi-person households (62.5±0.2, P<0.0001). Single-person households showed higher food insecurity and poorer dietary quality than multi-person households. These findings suggest the need for targeted nutritional interventions and policies to address the dietary disparities across different household types in Korea.

최근 수년간 터키, 인도네시아, 멕시코 등 전세계 곳곳에서 대규모의 지진이 발생하였으며 지진피해는 막대한 인적, 물적 피해를 초래하여 심각성을 일깨우고 있다. 대한민국과 인접 국가인 일본은 난카이 대지진과 같은 위협이 다가오고 있으며 대한민국에 서도 2016년, 2017년 경주와 포항에 잇따라 지진이 발생하였다. 이에 따라 현재 대한민국에서 추구하고 있는 안전한 도시환경을 구축 하기 위해서는 지진 재해 대응설계와 연구가 고도화될 필요가 있다. 본 연구에서는 지진 하중의 에너지를 소산함으로써 구조물이 견딜 수 있도록 하는 댐퍼에 대한 연구를 수행하였다. 일반적으로 재료의 항복을 통해 에너지 소산을 유도하는 강재댐퍼의 효율성을 높이기 위해 루프형 댐퍼를 제안하였다. 루프형 댐퍼는 단일 개체로 이뤄진 띄 형태의 강재가 루프형상을 갖으며 이어지는 댐퍼형태를 갖는다. 해당 댐퍼는 혁신적인 구조를 통해 비교적 작은 강재를 사용해도 큰 에너지 소산을 유도할 수 있다. 이를 입증하기 위해 형상적 변수를 설정하여 ABAQUS 프로그램을 사용한 유한요소해석을 수행하였고 힘-변위 그래프, 최대하중, 에너지 소산 등 댐퍼의 성능을 파악할 수 있는 결과를 도출하여 비교분석 하였다. 결과적으로 더 적은 강재를 사용해도 큰 에너지 소산, 최대하중 성능을 도출할 수 있음을 입증하였으며 추후 연구에서 신뢰성을 향상시키기 위한 실험과 실용성을 입증하기 위한 실제 지진하중 적용 프레임 구조물 수치해석을 진행하고자 한다.