Camellia japonica L. is highly valued for its ornamental and industrial applications. However, existing limitations in conventional seed and cutting propagation necessitate the development of a stable and efficient mass propagation system. This study systemically optimized each critical stage of in vitro culture—including shoot and root development, multiple shoot induction, rooting, and acclimatization —and quantitatively assessed the overall efficiency using integrated indices. Shoot growth was most vigorous on Woody Plant Medium (WPM) without the addition of indole-3-butyric acid (IBA), while root development was notably promoted by Murashige and Skoog (MS) medium supplemented with IBA. The highest number of multiple shoots was produced using basal explants cultured on MS medium containing 0.5 mg/L thidiazuron (TDZ), yielding an average of 2.67 shoots per explant. Optimal root induction was observed following a 15-min pulse treatment with 500 mg/L IBA (producing 24,33 roots), whereas the root elongation was maximized by a 5-min treatment with 1000 mg/L IBA (2.10 cm). Acclimatization successfully resulted in 100% survival in both tested substrates (A: peat moss, perlite, and cocopeat mixed in a 3:1:1 ratio; B: peat moss, perlite, and vermiculite mixed in a 1:1:1 ratio), with substrate B promoting a greater increase in plant height. Normalized growth parameters were averaged to calculate the Camellia Micropropagation Index (CMI). Integrated analysis identified the most efficient treatments as: WPM without IBA (shoot growth), MS with IBA (root growth), MS + 0.5 mg/L TDZ with basal explants (multiple shoots), 1000 mg/L IBA for 5 min (rooting), and substrate B (acclimatization). Despite these optimal conditions, considerable variation within treatments suggests that further fine-tuning or long-term evaluation is necessary to improve reliability. These findings provide a robust guideline for establishing a successful in vitro mass micropropagation system for C. japonica.

This study optimized the extraction of β-carotene and antioxidant compounds from orange-fleshed sweet potato (Ipomoea batatas L.) using response surface methodology (RSM) with ethyl lactate as a green solvent. A central composite design (CCD) was utilized to evaluate how the solvent-to-sample ratio, temperature, and extraction time affected efficiency. The regression model was statistically significant (Adj. R2=0.67), revealing that the solvent-to-sample ratio was the most influential factor, while temperature and time had relatively minor effects. The optimal conditions identified were a ratio of 12 mL/g, a temperature of 35°C, and an extraction time of 30 minutes, which resulted in a yield of 27 mg/100g of β-carotene, along with high levels of polyphenols, flavonoids, and strong antioxidant activities as measured by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline- 6-sulfonic acid)) assays. Validation experiments demonstrated a close alignment between predicted and experimental values, confirming the model's robustness. These findings indicate that ethyl lactate effectively extracts not only carotenoids but also a wide range of antioxidants, underscoring its potential as a sustainable solvent for developing functional food ingredients.

본 연구는 도시공원녹지의 공간적 형평성과 서비스 균형성을 평가하기 위한 지표를 탐색하고 공원 조성의 효과를 객관적으로 평가함으로써 도시 녹지 계획에 이론적 근거를 제공할 수 있는 자료 획 득을 목적으로 시도되었다. 이를 위해 네트워크분석법과 공간구문론을 기반으로 중국 산둥성 옌타 이시 중심 지역의 공원을 대상으로 다양한 교통수단 하에서의 접근성과 사용자 관점에서의 전역 및 국지 접근성을 분석하였다. 분석 결과, 푸산구는 전체적인 도로망이 더 통합적이고 연결성이 높아 전역 접근성이 가장 높은 것으로 나타났다. 또한, 즈푸구와 푸산구의 국지 접근성은 1.6km 서비스 반경 내에서 가장 높게 나타났으며 이들 지역의 국지적 도로망은 중심성과 통합성이 높은 구조를 보였다. 접근성의 불균형은 주로 공원의 수와 위치의 공간적 분포가 불균형하고 인구 밀도 와의 적합성이 낮으며 일부 공원의 접근성 수준이 공원 유형과 일치하지 않는 데에 기인한다. 본 연구를 통해 공원의 종합적 접근성을 향상시키고 녹지 공간 배치를 최적화하기 위한 방안으로는 중소형 공원의 추가 조성과 주거 지역을 주요 수요지로 고려하며 지선 구조와 대중교통 체계를 개 선하는 등의 전략을 제안하고자 한다.

리튬 이온 배터리의 안전성과 지속가능성에 대한 수요 증가는 기존의 폴리올레핀 분리막을 대체할 수 있는 셀룰 로오스 기반 분리막 개발을 촉진하고 있다. 본 총설은 수압 공정을 통해 제조된 셀룰로오스 아세테이트(cellulose acetate, CA) 분리막의 최적화 전략을 종합적으로 분석하였다. 특히, 기공 구조, 열적 안정성, 기계적 강도를 조절하는 데 있어 유기 및 무 기 첨가제의 역할을 중점적으로 고찰하였다. 유기산은 고분자 사슬의 가소화를 통해 나노기공 형성을 유도하여 높은 기공률 과 조절 가능한 기공 크기를 제공하지만, 열적 안정성이 다소 저하되는 한계가 있다. 반면, 무기 염과 산화물, 특히 칼슘계 화 합물은 이온 상호작용과 가교결합을 통해 열적 안정성을 크게 향상시키는 것으로 나타났다.

In this study, the aim was to establish a pre-treatment process to utilize citrus pomace (CP) as a high-value-added material. Frozen CP was thawed under various conditions, including at room temperature, using ultrasound, and immersion at 25℃ and 70℃, and samples from each thawing group were assigned to a non-washed (NW) or a washed (W) group. The samples in the W-CP groups were drained, and all samples were powdered after hot air drying. The samples in the NW-CP groups had a two-fold higher drying yield of CP powder, a significantly lower pH (4.20–4.26), and a higher soluble solids content (1.1–1.3°Brix) than the samples in the W-CP groups. Interestingly, the samples in the W-CP groups had significantly higher swelling capacity (8.18–8.53 mL/g), water absorption index (7.61–7.85 g/g), water holding capacity (8.92–10.30 g/g), and oil holding capacity (2.09–2.30 g/g) than samples in the NW-CP groups (p<0.05). Conversely, the thawing method only significantly affected the thawing rate of the CP, but it did not significantly affect the properties of the CP powder. The results of this study provide basic data for the industrialization and resource utilization of CP, and they suggest that various pre-treatment processes can influence CP standardization.

Protein is an essential nutrient for sustaining human life; however, securing sufficient protein through the traditional livestock industry is predicted to become difficult in the future. Microalgae have high potential as alternative protein sources owing to their efficiency in resource utilization and sustainability. The major challenge in the high value-added use of microalgae is the effective recovery of their small cells. Electro-coagulation technology is a harvesting method that has little direct or indirect effect on microalgae and causes no environmental pollution. To optimize the harvest yield of Scenedesmus obliquus, this study examined how stirring, stirring speed, initial pH, electrode material, current density, current intensity, electrode spacing, and electrode placement affected microalgae recovery and determined optimal harvest conditions. The optimal culture conditions were a stirring speed of 100 rpm, initial pH of 5.0, using aluminum electrodes, current density of 20 A/m2, current intensity of 0.3 A, electrode spacing of 1 cm, and electrode placement of (–) electrode, (+) electrode, (–) electrode. These findings can be used to increase the harvest yield of microalgae as an alternative protein resource.

Carbon nanotube (CNT) has promising applications in several fields due to their excellent thermal, electrical, mechanical, and biocompatible properties. However, the complexity of its structure leads to the problems of computationally intensive and inefficient synthetic characterization optimization and prediction by traditional research methods, which seriously restricts the development process. Machine learning (ML), as an emerging technology, has been widely used in CNT research due to its ability to reduce computational cost, shorten the development cycle, and improve the accuracy. ML not only optimizes the synthetic control parameters for precise structural control, but also combines various imaging and spectroscopic techniques to significantly improve the accuracy and efficiency of characterization. In addition, ML helps to improve the performance of CNT devices at the optimization and prediction levels, and achieve accurate performance prediction. However, ML in CNT research still faces challenges such as algorithmic processing of complex data situations, insufficient space for algorithmic combined optimization, and lack of model interpretability. Future research can focus on developing more efficient ML algorithms and unified standardized databases, exploring the deep integration of different algorithms, further improving the performance of ML in CNT research, and promoting its application in more fields.

This study investigates the effect of different objective functions on the topology optimization of a loudspeaker basket for structural resonance avoidance. Three objective functions were considered: maximization of the first natural frequency, minimization of static strain energy, and minimization of dynamic strain energy. The results show that, for all objective functions, the first natural frequency increased significantly compared to the initial design, while both static and dynamic strain energies were reduced, indicating effective suppression of structural resonance. Although the performance differences among the objective functions were not substantial, minimization of static and dynamic strain energy exhibited higher computational efficiency compared to natural frequency maximization. In particular, minimization of static strain energy demonstrated advantages in computational efficiency and ease of implementation, suggesting it as a practical alternative for resonance-avoidance design of loudspeaker baskets. This study highlights the importance of objective function selection by quantitatively comparing optimization outcomes under different formulations.

국내에는 현재 50,435척의 5톤 미만 어선이 존재하나, 국내외 법규상 이러한 선박에서 발생하는 선저폐수를 관리하기 위한 제 도적·기술적 장치가 마련되어 있지 않다. 이로 인해 무단으로 배출되는 선저폐수는 심각한 환경오염을 유발하고, 이에 따른 경제적 손실 도 발생한다. 이에 본 연구는 소형선박용 유수 분리 장치의 내부 유동 분포를 개선하기 위해 Filter case cover 형상을 개발하였다. 입구각 0°, 30°, 45°의 세 가지 형상을 대상으로 Computational Fluid Dynamics 해석을 수행하였으며, 45° 형상에서 균일한 속도 분포와 안정적 선회 유동이 형성되어 Filter 전체 면적을 효율적으로 활용하는 것을 확인하였다. 이후 상용 Filter 6종에 대해 단일 성능평가를 수행한 결과, 양 전하막 처리된 활성탄이 유성분 흡착에 효과적임을 확인하였다. 이를 기반으로 기계적 여과 필터와 활성탄 필터로 구성된 3단계 여과 시 스템을 제안하였으며, 30ppm 유수 혼합액을 이용한 실험에서 배출수의 유분 농도를 0ppm에 근접하게 낮추고, 장시간 운전 중에도 안정적 인 유량과 처리 특성을 유지하였다. 본 연구는 형상 및 필터 구성을 최적화하여 설계 효율이 향상된 소형선박용 유수 분리 시스템의 기초 기술을 제시하며, 국내 연안의 환경오염을 방지하고 지속 가능한 생태계를 조성하는데 기여할 수 있을 것으로 기대된다.

WC–Mo₂C–Co cemented carbides were fabricated to investigate the effects of Mo₂C addition on microstructure and mechanical properties. Dual hard-phase design using WC and Mo₂C was employed to optimize the balance between hardness and toughness. Spark plasma sintering (SPS) was conducted at various temperatures after ball milling, and 1300 °C for 5 min was identified as the optimized sintering condition, achieving complete densification and phase stability. The addition of Mo₂C refined the microstructure by suppressing abnormal WC grain growth through preferential dissolution of Mo₂C into the Co binder. Hardness increased up to 1769 Hv30 due to grain refinement and solid-solution strengthening, while promoted η-phase formation and reduced fracture toughness.The 27Mo₂C composition exhibited the most balanced combination of hardness and toughness. These results demonstrate that controlled Mo₂C addition enables dual hard-phase strengthening and microstructure optimization in WC–Mo₂C–Co carbides for advanced cutting and forming applications.

대부분의 원전 설비의 내진 해석에는 해석이 비교적 간편하고, 설계에 보수성을 적절히 반영할 수 있어 대부분 기기가 설치된 위치에서의 층응답스펙트럼 혹은 In-structure response spectrum을 이용한 응답스펙트럼 해석을 주로 이용하고 있다. 설비 공급자 는 설계 시방서에 층응답스펙트럼 선도의 형태로 입력 지진파 자료를 받게 되는데, 필요시 이를 바탕으로 인공 지진파을 만들어 해석 혹은 시험을 수행한다. 설계지반응답스펙트럼의 경우 RG 1.60에 주어지고 SRP 3.7.1의 요건에 따라 인공 지진파 시간 이력을 생성하 나, 층응답스펙트럼의 경우 명확은 기준이 없어 이를 따르고 있다. 층응답스펙트럼은 구조물의 동특성이 반영되기 때문에 지반응답스 펙트럼에 비해 형태가 복잡하여 기존의 P-CARES 등의 인공 지진파 생성 프로그램을 이용할 경우 SRP 3.7.1의 요건에 맞는 시간 이력 인공 지진파를 얻기 위해서는 상당한 노력이 필요하다. 본 연구에서는 수치 최적화를 이용하여 복잡한 형태의 층응답스펙트럼이 라도 SRP 3.7.1의 요건 내에서 그 형태를 따르는 인공 지진파 시간 이력을 효율적으로 생성할 수 있는 절차를 개발하였다.