title: Four-dimensional visualization of rising microbubbles.
abstract: Four-dimensional imaging, which indicates imaging in three spatial dimensions as a function of time, provides useful evidence to investigate the interactions of rising bubbles. However, this has been largely unexplored for microbubbles, mostly due to problems associated with strong light scattering and shallow depth of field in optical imaging. Here, tracking x-ray microtomography is used to visualize rising microbubbles in four dimensions. Bubbles are tracked by moving the cell to account for their rise velocity. The sizes, shapes, time-dependent positions, and velocities of individual rising microbubbles are clearly identified, despite substantial overlaps between bubbles in the field of view. Our tracking x-ray microtomography affords opportunities for understanding bubble-bubble (or particle) interactions at microscales - important in various fields such as microfluidics, biomechanics, and floatation.
authors.affiliation: X-ray Imaging Center, Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, Korea.
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Jung
authors.affiliation: X-ray Imaging Center, Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, Korea.
authors.forename: Hyung Min
authors.initials: HM
authors.lastname: Jeon
authors.affiliation: X-ray Imaging Center, Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, Korea.
authors.forename: Jaeyeon
authors.initials: J
authors.lastname: Pyo
authors.affiliation: Pohang Accelerator Laboratory, San 31, Hyoja-dong, Pohang 790-784, Korea.
authors.forename: Jae-Hong
authors.initials: JH
authors.lastname: Lim
authors.affiliation: School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Byung Mook
authors.initials: BM
authors.lastname: Weon
authors.affiliation: RIKEN/SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Kohmura
authors.affiliation: RIKEN/SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ishikawa
authors.affiliation: 1] X-ray Imaging Center, Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, Korea [2] RIKEN/SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Je