Photometric and spectroscopic observations of GV Leo were performed from 2017 to 2024. The light curves show a flat bottom at the primary eclipse and the conventional O’Connell effect. The echelle spectra reveal that the effective temperature and rotation velocity of the more massive secondary are Teff,2 = 5220 ± 120 K and v2 sin i = 223 ± 40 kms−1, respectively. Our binary modeling indicates that the program target is a W-subclass contact binary with a mass ratio of q = 5.48, an inclination angle of i = 81.◦68, a temperature difference of (Teff,1 − Teff,2) = 154 K, and a filling factor of f = 36%. The light asymmetries were reasonably modeled by a dark starspot on the secondary’s photosphere. Including our 26 minimum epochs, 84 times of minimum light were used to investigate the orbital period of the system. We found that the eclipse times of GV Leo have varied by a sinusoid with a period of 14.9 years and a semi-amplitude of 0.0076 days superimposed on a downward parabola. The periodic modulation is interpreted as a light time effect produced by an unseen outer tertiary with a minimum mass of 0.26 M⊙, while the parabolic component is thought to be a combination of mass transfer (secondary to primary) and angular momentum loss driven by magnetic braking. The circumbinary tertiary would have caused the eclipsing pair of GV Leo to evolve into its current short-period contact state by removing angular momentum from the primordial widish binary.

The transportation of spent nuclear fuel between management stages is expected, and the transportation workers may be exposed to radiation. When transporting spent nuclear fuel, the ALARA principle must be observed for the workers. The objective of this study is to assess a radiation dose for workers transporting spent nuclear fuel using metal overpacks. For this objective, the cask to be handled was selected and the radiation source term was set. Then, the radiation exposure scenario for the transportation workers was defined. Finally, the dose rates for each location of operation were assessed using Monte Carlo simulations, and collective doses were derived for each operation considering the radiation exposure scenario. Each worker performed 11 operations to transport spent nuclear fuel to other facilities and was exposed to a total of 1.138 man-mSv. The operation of removing the bottom shield ring resulted in the highest radiation exposure at 0.503 man-mSv. In contrast, the operation of installing the impact limiter resulted in the lowest radiation exposure at 0.0009 man-mSv. The results of this study can be used to strengthen radiation protection measures for workers transporting spent nuclear fuel in dry storage facilities using metal overpacks.

The increase in radioactive waste increased the demand for transportation to the disposal facility. Prior to transporting radioactive waste, confirming that the potential exposure is insignificant is crucial. Overland transportation risk assessment models were developed tailored to domestic characteristics. Dose assessment using this model requires selecting appropriate factors. However, users may struggle to derive appropriate values, leading to inaccuracies. Additionally, if assessment results show outliers, prioritizing factors for review can be challenging. Therefore, sensitivity analysis is necessary to prioritize factors for accurate assessment. In this study, sensitivity analysis was conducted on the on-link public risk assessment model factors for radioactive waste overland transportation. Initially, assessment models were analyzed by each detailed exposure scenario. Subsequently, uncertainty propagation-based sensitivity analysis methodology was applied. The default values for the assessment model factors were set, and sensitivity analysis was conducted based on road type for maximum individual and collective dose assessment models. For the maximum individual dose model, the distance to the samedirection vehicle was the most sensitive, whereas for the collective dose model, vehicle velocity was the most sensitive. The results of this study can be used as the basic data on radioactive waste transportation risk assessment in Korea in the future.

목적 : 디지털 시기능 훈련용 게이밍 프로그램을 사용하여 대상자의 시기능 훈련 후 양안시기능의 변화를 조사 하였다. 방법 : 본 연구는 전신질환, 안과적 질환, 과거 수술력이 없고 사시 진단을 받지 않은 신체 건강한 성인 25명(남 자 14명, 여자 11명)을 대상으로 하였다. 언리얼 엔진을 기반으로 한 게이밍 프로그램은 시기능을 강화 및 훈련하 기 위한 목적으로 개발되었다. 모든 피검자에게 디지털 시기능 훈련용 프로그램을 한달 동안 일주일 2회, 30분간 시행하여 훈련을 진행하였다. 결과 : 디지털 시기능 훈련 전과 후의 조절근점은 13.08±2.26 cm에서 10.15±3.41 cm으로 향상되었다. 조절 용이성은 12.05±1.20회에서 9.78±1.32회로 개선되어 선명하게 초점을 맺는데 시간이 단축되었다(p<0.050). 버 전스용이성(Vergence facillity)은 12.89±2.34 회에서 9.14±1.75 회로 통계적으로 유의하게 향상되었다(p< 0.050). 외사위도는 –2.48±2.56 Δ(exo.)에서 -1.07±1.23 Δ(exo.)으로 외사위량이 통계학적으로 유의하게 감소 하였고(p<0.050) 양성융합버전스 분리점은 21.99±4.26 Δ에서 24.55±2.89 Δ으로 개선되었고 음성융합버전스 분리점은 평균 17.57±2.12 Δ에서 18.69±1.60 Δ으로 약 0.1 Δ이 소폭 증가하였다. 결론 : 디지털 시기능 훈련으로 연구 대상자들의 외사위도가 감소하였고 조절력, 조절 및 버전스 용이성과 안구 운동성 능력이 개선되는 것을 알 수 있었다. 디지털 시기능 훈련은 안구 운동성 기능과 양안시기능이 중요한 직군 의 사람들에게 도움을 줄 수 있고 다양하게 활용될 수 있는 활용가치 및 잠재력을 가지고 있다.

꼬리말발도리(Deutzia paniculata Nakai)와 가침박달 (Exochorda serratifolia S.Moore)은 각각 5~6월과 4~5월에 흰색 꽃이 피는 화목관목으로 한국의 희귀식물이며, 관상가치가 높아 원예용으로 개발할 가치가 있다. 본 연구에서는 꼬리말발 도리와 가침박달의 종자를 이용한 번식체계를 확립하고자 플러 그 육묘에서 플러그 트레이의 셀 크기, 배지조성, 시비수준에 따른 유묘의 생육을 조사하였다. 꼬리말발도리는 플러그 트레이 의 셀 크기가 작아질수록 유묘의 생육이 불량하였고, 105구의 셀 크기에서 초장, 엽장과 엽폭, 줄기와 뿌리의 생체중 등 생육 이 가장 양호하였다. 또한 배지의 조성은 피트모스와 펄라이트 를 20:80로 혼합한 처리에서 줄기와 뿌리의 생육이 가장 우수하 였고, 펄라이트 단용인 0:100 처리에서 유묘의 생육이 가장 불 량하였다. 가침박달은 피트모스와 펄라이트를 100:0과 75:25 로 혼합한 배지에서 유묘의 생육이 가장 좋았고, 펄라이트 단 용인 0:100 배지에서 유묘의 줄기뿐만 아니라 뿌리의 생육 도 가장 불량하였다. 그리고, 육묘 기간동안 시비수준이 증가 함에 따라 유묘의 줄기 생육이 양호하였으며, 엽록소의 함량도 증가하였다. 따라서 가침박달은 플러그 트레이 당 Hyponex (N:P:K=20:20:20) 6.24.g을 관주하는 것이 고품질 묘를 생산 하는데 가장 효과적이었다. 따라서 꼬리말발도리는 105공 플러 그 트레이에 피트모스와 펄라이트의 20:80 비율의 배지를 사용 하는 것이, 가침박달은 피트모스와 펄라이트의 100:0과 75:25 비율의 배지에서 육묘기간동안 Hyponex 6.24g를 시비하는 것이 유묘 생육에 가장 적합하였다.

Because intact FMDV particles (146S) are often unstable in vitro, stabilizing foot-and-mouth disease virus (FMDV) antigens remains a key challenge in studying viral charateristics. Therefore, finding optimal condition to stabilize the FMDV is essential. In this study, we investigated formulations and potentials of several stabilizers such as appropriate buffer, excipients, and storage conditions to enhance the stability of 146S. Inactivated FMDV O-Jincheon (O-JC) was dissolved in various buffer formulations, and stored at 4℃ for two months to evaluate quantity of 146S at every 2-week interval. Among phosphate buffered saline (PBS), Tris buffered saline (TBS), HEPES buffered saline (HBS), and MOPS buffered saline (MBS), PBS showed more effective 146S stabilization that showed 1.3-1.6 fold higher 146S fraction than TBS, HBS, and MBS after storage for 2 weeks. However, constant dissociations of 146S were observed in all formulations at 8 weeks. Compared with other FMDVs, A22 Iraq and SAT-1, in PBS, O-JC proved to be the least stable in PBS. A variety of excipients including carbohydrate, sugar alcohol, cryo-protectant were tested for the capability in protecting O-JC from dissociation. By adding 4-8% sucrose, more than 60% of 146S fractions were maintained at 8 weeks, those were at least 1.8 fold higher than the PBS-only control. Addition of 1% β-cyclodextrin showed synergistic enhancement in O-JC stability. As the results of this study, it could be suggested that the PBS-based buffer together with 4-8% sucrose + 2% sorbitol or 2% sucrose + 2% sorbitol + 1% β-cyclodextrin could help the better stability of the O-JC in vaccine preparation.

This study evaluated the applicability of existing overseas-developed allometric equations for estimating the biomass of domestic apple trees (Malus domestica) in South Korea. To assess their suitability, predicted biomass values derived from these equations were compared with actual measurements obtained through destructive sampling. The results indicate that some overseas equations showed no significant difference when applied to domestic apple trees, suggesting their potential applicability to local conditions. However, it was also noted that certain equations may not fully capture the unique characteristics of domestic apple trees, such as the slender spindle form associated with modern high-density planting practices. Given these findings, the study highlights the need to develop new allometric equations that are specifically optimized for the growth characteristics and cultivation environments of domestic apple orchards. Such equations would enable more accurate biomass estimation, support agricultural sustainability, and provide reliable data for the national greenhouse gas inventory. This research is expected to serve as a foundation for future Tier 2-level studies on biomass and carbon sequestration in apple orchards while also underscoring the importance of expanding research to include various fruit tree species to develop customized biomass estimation models for enhanced agricultural management and environmental conservation.

In this study, carbon coating was carried out by physical vapor deposition (PVD) on SiOx surfaces to investigate the effect of the deposited carbon layer on the performance of lithium-ion batteries as a function of the asphaltene content of petroleum residues. The petroleum residue was separated into asphaltene-free petroleum residue (ASF) and asphaltene-based petroleum residue (AS) containing 12.54% asphaltene by a solvent extraction method, and the components were analyzed. The deposited carbon coating layer became thinner, with the thickness decreasing from 15.4 to 8.1 nm, as the asphaltene content of the petroleum residue increased, and a highly crystalline layer was obtained. In particular, the SiOx electrode carbon-coated with AS exhibited excellent cycling performance with an initial efficiency of 85.5% and a capacity retention rate of 94.1% after 100 cycles at a current density of 1.0 C. This is because the carbon layer with enhanced crystallinity had sufficient thickness to alleviate the volume expansion of SiOx, resulting in stable SEI layer formation and enhanced structural stability. In addition, the SiOx electrode exhibited the lowest resistance with a low impedance of 23.35 Ω, attributed to the crystalline carbon layer that enhanced electrical conductivity and the mobility of Li ions. This study demonstrated that increasing the asphaltene content of petroleum residues is the simplest strategy for preparing SiOx@C anode materials with thin, crystalline carbon layers and excellent electrochemical performance with high efficiency and high rate performance.

The AlSi10Mg alloy has garnered significant attention for its application in laser powder bed fusion (L-PBF), due to its lightweight properties and good printability using L-PBF. However, the low production speed of the L-PBF process is the main bottleneck in the industrial commercialization of L-PBF AlSi10Mg alloy parts. Furthermore, while L-PBF AlSi10Mg alloy exhibits excellent mechanical properties, the properties are often over-specified compared to the target properties of parts traditionally fabricated by casting. To accelerate production speed in L-PBF, this study investigated the effects of process parameters on the build rate and mechanical properties of the AlSi10Mg alloy. Guidelines are proposed for high-speed additive manufacturing of the AlSi10Mg alloy for use in automotive parts. The results show a significant increase in the build rate, exceeding the conventional build rate by a factor of 3.6 times or more, while the L-PBF AlSi10Mg alloy met the specifications for automotive prototype parts. This strategy can be expected to offer significant cost advantages while maintaining acceptable mechanical properties of topology-optimized parts used in the automobile industry.