농작물의 수분 매개자이며 생태계 유지에 필수적인 역할을 하는 꿀벌의 노제마병(nosemosis)은 꿀벌 집단 붕괴현상(colony collapse disorder: CCD)의 원인 중 하나로 알려져 있다. 또한, 노제마병은 봉군 약화를 초래할 뿐 아니라 여러 가지 양봉 산물의 생산성을 낮추는 원인이기도 하다. 국내에서는 Nosema ceranae가 노제마병의 주요 병원체로 알려져 있다. 노제마 감염을 확인하기 위해서는 꿀벌의 중장을 적출한 후 노제마 포자의 확인 및 계수를 통해 감염 수준을 평가할 수 있다. 본 연구에서는 더욱 빠르고 정확하게 노제마 감염 수준을 평가할 수 있는 새로운 방법으로 포자 염색법과 qPCR 방법을 개발하였다. 노제마 포자에 대해 특이적인 염색이 가능한 Fluorescent Brightener를 이용하여 노제마 감염 꿀벌 중장을 염색한 결과, 형광 발현으로 노제마의 감염 여부를 확인할 수 있었다. 또한, 중장내 포자량에 비례한 형광 발현도 확인할 수 있었다. 그러나, 노제마 감염에 대한 특이도 및 포자량에 비례한 형광 발현 민감도는 신뢰하기 어려웠다. 그에 비해, 노제마 특이 유전자를 이용한 qPCR 방법은 노제마의 감염 여부 뿐만 아니라 포자량에 비례한 감염 수준 결정이 가능함을 확인하였다. 특히, 많은 시료들에서 노제마 감염 수준의 신속하고 정확한 평가에 qPCR 방법은 유용하게 활용될 수 있을 것으로 기대되었다.

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.

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.