Yonsei University

About: Yonsei University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Cancer. The organization has 50162 authors who have published 106172 publications receiving 2279044 citations. The organization is also known as: Yonsei.

Recent developments in superhydrophobic surfaces with unique structural and functional properties

Abstract: The surface wettability control of solid materials has been considered as an essential aspect of surface chemistry. In the past decade, superhydrophobic surfaces have revealed a cornucopia of novel structural and functional properties, exhibiting considerable importance in both fundamental research and practical applications. In this review, we summarize the recent developments of superhydrophobic surfaces with unique structural and functional properties. Both the fabricative methods and the working performance of superhydrophobic surfaces with multidisciplinary functionalities including self-cleaning, icephobicity, anti-corrosion, drag reduction, transparency, anti-reflection, structural color, droplet transportation, anisotropy, oil–water separation, water supporting force, superamphiphobicity and responsive switching, have been discussed briefly. Finally, the current challenges and future prospects of this dynamic field are discussed based on our own opinion.

UV-optical colors as probes of early-type galaxy evolution

Abstract: We have studied ~2100 early-type galaxies in the SDSS DR3 which have been detected by the GALEX Medium Imaging Survey (MIS), in the redshift range 0 < z < 0.11. Combining GALEX UV photometry with corollary optical data from the SDSS, we find that, at a 95% confidence level, at least ~30% of galaxies in this sample have UV to optical colors consistent with some recent star formation within the last Gyr. In particular, galaxies with an NUV − r color less than 5.5 are very likely to have experienced such recent star formation, taking into account the possibility of a contribution to NUV flux from the UV upturn phenomenon. We find quantitative agreement between the observations and the predictions of a semianalytical ΛCDM hierarchical merger model and deduce that early-type galaxies in the redshift range 0 < z < 0.11 have ~1%-3% of their stellar mass in stars less than 1 Gyr old. The average age of this recently formed population is ~300-500 Myr. We also find that "monolithically" evolving galaxies, where recent star formation can be driven solely by recycled gas from stellar mass loss, cannot exhibit the blue colors (NUV − r < 5.5) seen in a significant fraction (~30%) of our observed sample.