Hemispherical confocal imaging using turtleback reflector

We propose a new imaging method called hemispherical confocal imaging to clearly visualize a particular depth in a 3-D scene. The key optical component is a turtleback reflector which is a specially designed polyhedral mirror. By combining the turtleback reflector with a coaxial pair of a camera and a projector, many virtual cameras and projectors are produced on a hemisphere with uniform density to synthesize a hemispherical aperture. In such an optical device, high frequency illumination can be focused at a particular depth in the scene to visualize only the depth with descattering. Then, the observed views are factorized into masking, attenuation, and texture terms to enhance visualization when obstacles are present. Experiments using a prototype system show that only the particular depth is effectively illuminated and hazes by scattering and attenuation can be recovered even when obstacles exist.Microsoft ResearchJapan Society for the Promotion of Science (Grants-in-Aid For Scientific Research 21680017)Japan Society for the Promotion of Science (Grants-in-Aid For Scientific Research 21650038

Light Transport Refocusing for Unknown Scattering Medium

2014 22nd International Conference on Pattern Recognition,Stockholm, Sweden,24-28 Aug. 2014In this paper we propose a new light transport refocusing method for depth estimation as well as for investigation inside scattering media with unknown scattering properties. Propagated visible light rays through scattering media are utilized in our proposed refocusing method. We use 2D light source to illuminate the scattering media and 2D image sensor for capturing transported rays. The proposed method that uses 4D light transport can clearly visualize shallow depth, as well as deep depth plane of the medium. We apply our light transport refocusing method for depth estimation using conventional depth-from-focus method and for clear visualization by descattering the light rays passing through the medium. To evaluate the effectiveness we have done experiments using acrylic and milk-water type scattering medium in various optical and geometrical conditions. Finally, we show up the results of depth estimation and clear visualization, as well as with numeric evaluation

Picosecond pulse radiolysis: Dynamics of solvated electrons in ionic liquid and geminate ion recombination in liquid alkanes

金沢大学理工研究域自然システム学系A picosecond pulse radiolysis facility based on a laser-driven photocathode electron accelerator has been constructed. First observation of picosecond dynamics in ionic liquid of DEMMA-TFSI in radiation chemistry was reported. It is found that the electrons produced by ionization are solvated to full solvation in ionic liquid with a rate constant of 3.9×1010 s-1, and dry electrons before full solvation react rapidly with biphenyl and pyrene with a rate constant of 3.8-7.9×1011 dm3 mol-1 s-1. The geminate ion recombination in n-dodecane and n-hexane was also observed by monitoring transient optical absorption at 523 nm. © 2008 Elsevier Ltd. All rights reserved

Editorial

The Pacific Polymer Federation, PPF, was founded in 1987 by the Polymer Division of the American Chemical Society, the Society of Polymer Science, Japan and the Polymer Division of the Royal Australian Chemical Institute at signing ceremony in Tokyo, Japan. Since then other Pacific Basin societies have jointed the Federation, and the Federation is currently comprised of seventeen member societies all drawn from Pacific Basin Nations. The PPF holds biennial conferences, and the eleventh conference, PPC-11, was held in Cairns, Australia on December 6–11, 2009 and co-chaired by Andrew Whittaker and Wayne Cook from Australia. Approximately 1000 delegates attended PPC-11. A symposium on the Radiation Modification of Polymers formed part of the technical program for PPC-11 and was organized by Seiichi Tagawa, Osaka University, Japan; Olgun Güven, Hacettepe University, Turkey; and David Hill, The University of Queensland, Australia. The symposium occupied three days of PPC-11 and the program included oral and poster papers on the radiation chemistry of polymers, with several sessions allocated to the special topic of photolithography that was organized by Idriss Blakey, The University of Queensland, Australia. In addition, one session of the symposium was sponsored by RADTECH Asia and was organized by Seiichi Tagawa. The papers which constitute this special issue have been drawn from papers presented at the Radiation Modification of Polymers symposium. While studies of the effects of high-energy radiations on polymers continue to attract the attention of many researchers, the fundamental principles that underlie the interaction of high-energy radiations with polymers are now well established. Thus most of the papers at the symposium were devoted to applications of high-energy radiation in various fields of polymer science, ranging from applications in photolithography to biomedicine. The types of radiations used in the studies reported in the symposium were also very broad, and covered heavy ion and electron beams and short wavelength electromagnetic radiation, including gamma and X-radiations, as well as VUV radiation. The Keynote speakers at the symposium were: Mohamad Al-Sheikhly, University of Maryland, USA Olgun Güven, Hacettepe University, Turkey Reinhard Neumann, GSI, Germany Tadatomi Nishikubo, Kanagawa University, Japan Seiichi Tagawa, Osaka University, Japan Masakazu Washio, Waseda University, Japan Yoichi Yoshida, Osaka University, Japan As editors of this special issue, we wish to thank all those who have contributed manuscripts to this representative compendium of papers from the symposium. We also wish to thank those who have contributed by reviewing the manuscripts and/or attending the symposium sessions. Finally, we wish to express our gratitude to the Editors of Radiation Physics and Chemistry and to Tingting Zou and the other staff at Elsevier for assisting us in producing this peer-reviewed publication of a selection of the papers presented at PPC-11, despite the short notice of our initial request to do so