January 2008 Archives

Fast liquid jets and sprays, which are complex multiphase flow phenomena, have been one of physics' veiled mysteries ever since the pioneering work by Rayleigh in the 19^th century (See, W. S. Rayleigh, "On the stability of jets", Proc. Lond. Math. Soc. 4, 10 (1878)). The main reason is simply that standard microscopy and visible light imaging techniques cannot peer into the dark and murky centers of dense-liquid jets. Recently, Dr. K. Fezzaa and his colleagues (Argonne National Lab, USA) have succeeded in revealing for the first time the morphology and velocity fields of high-speed and highly turbulent jets generated by a gasoline direct injection system. The research group employed ultrafast synchrotron-X-ray full-field phase-contrast imaging. The spatial and time resolutions in the experiments were 5-30 micron and 472 ns, respectively. For more information on the present experiments, see the paper, "Ultrafast X-ray study of dense-liquid-jet flow dynamics using structure-tracking velocimetry", Y. Wang et al., Nature Physics, advanced online publication, DOI: 10.1038/nphys840

The international union of crystallography (IUCr) announced that Professor D. Sayre (Department of Physics, State University of New York, Stony Brook, NY 11794, USA) has been awarded the eighth Ewald Prize for the unique breadth of his contributions to crystallography, which range from seminal contributions to the solving of the phase problem to the complex physics of imaging generic objects by X-ray diffraction and microscopy, and for never losing touch with the physical reality of the processes involved. The presentation of the Ewald Prize will be made during the Osaka Congress Opening Ceremony in August 2008. Former recipients of the Ewald Prize are P. Coppens (USA, 2005), Michael M. Woolfson (UK, 2002), G. N. Ramachandran (India, 1999), M. G. Rossmann (USA, 1996), N. Kato (Japan, 1993), B.K. Vainshtein (Russia, 1990), J.M. Cowley (USA) and A.F. Moodie (Australia) in 1987.

A coherent X-ray beam produces a speckle pattern when it impinges on a sample. Usually the size and shape of the speckle do not depend on the sample at all, but a group led by Professor M. Giglio (Universita degli Studi di Milano, Italy) recently found significant effects, observed when the detector is placed in the near field. Conventional far-field techniques, because of the van Cittert and Zernike theorem, have limitations in the statistical analysis of speckles, but it has now become possible to generate static and dynamic X-ray-scattering data. In addition, the present technique permits an increase of around four orders of magnitude in beam size and power. The measurements were done at BM05, European Synchrotron Radiation Facility (ESRF) in Grenoble, France. The peak energy was 12 keV and the beam size at the sample position was 1 mm × 1 mm. For more information, see the paper, "X-ray-scattering information obtained from near-field speckle", R. Cerbino et al., Nature Physics, advanced online publication, DOI: 10.1038/nphys837

A joint research group from the USA and Australia, led by Dr. J. Miao (University of California-Los Angeles) recently published the first results of resonant X-ray diffraction microscopy for element specific imaging of buried structures with a pixel resolution of ~15 nm by exploiting the abrupt change in the scattering cross section near electronic resonances. They performed nondestructive and quantitative imaging of buried Bi structures inside a Si crystal by directly phasing coherent X-ray diffraction patterns near the Bi-MV edge. For more information, see the paper, "Nanoscale Imaging of Buried Structures with Elemental Specificity Using Resonant X-Ray Diffraction Microscopy", C. Song et al., Phys. Rev. Lett., 100, 025504 (2008).

The Science and Technology Foundation of Japan has announced that three US scientists have been named as laureates of the 2008 (24th) Japan Prize. Dr. Vinton Gray Cerf, 64, Google Inc., and Dr. Robert Elliot Kahn, 69, Corporation for National Research Initiatives, have received the prize in this year's category of "Information Communication Theory and Technology". Dr. Victor A. McKusick, 86, the Johns Hopkins University, has been selected in another prize category of "Medical Genomics and Genetics." They will receive certificates of merit, and commemorative medals. There is also a cash award of fifty million Japanese yen for each prize category. The presentation ceremony is scheduled to be held in Tokyo at the National Theatre on Wednesday 23rd April, 2008. The prize categories for the 2009 (25th) Japan Prize will be "The transformation towards a sustainable society in harmony with nature" and the "Technological integration of medical science and engineering". For further information, contact Masaaki Ueda, The Science and Technology Foundation of Japan, Phone: +81-3-5545-0551, Fax: +81-3-5545-0554, info@japanprize.jp, http://www.japanprize.jp/English.htm

A German group led by Dr. B. Kanngiesser (Technische Universitat Berlin) has recently reported the significant extension of 3D micro X-ray fluorescence (XRF) spectroscopy. Conventional XRF mapping is likely to remain a non-absolute analysis, since it just gives the spatial distribution of elements in the viewing region. On the other hand, most realistic analytical applications require much greater quantitative imaging of chemical composition, density, thickness of layers etc. The research group attempted to introduce a reliable quantification procedure, and obtained successful results in the case of stratified material. For more information, see the paper, "Reconstruction of Thickness and Composition of Stratified Materials by Means of 3D Micro X-ray Fluorescence Spectroscopy", I. Mantouvalou et al., Anal. Chem. ASAP Article, DOI: 10.1021/ac701774d