Hua Jin

Publications (2)2.83 Total impact

• Source

  Available from: Clinton Willson

  Article: Three-dimensional chemical analysis with synchrotron tomography at multiple X-ray energies: Brominated aromatic flame retardant and antimony oxide in polystyrene

  Kyungmin Ham, Hua Jin, Riyadh Al-Raoush, Xiaogang Xie, Clinton S Willson, Gary R Byerly, Larry S Simeral, Mark L Rivers, Richard L Kurtz, Leslie G Butler
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  ABSTRACT: Synchrotron X-ray tomography is used to image, at 3.34 µm resolution, a mixture containing high-impact polystyrene (HIPS) and a two-component flame retardant, a brominated phthalimide dimer (Saytex BT-93), and a synergist, antimony oxide (Sb 2 O 3). Complete tomography data sets were acquired at seven X-ray energies in the range of 12-40 keV, closely spanning Br and Sb 1s electron binding energies at 13.474 and 30.491 keV, respectively. Data acquisition required 8 h. Quantification is done for a representative subvolume of 0.582 mm 3 containing 250 3 cubic volume elements (voxels) which is fitted to a model for X-ray voxel linear attenuation coefficient, yielding the three-dimensional concentration distribution of the flame retardant and the synergist. With successive thresholding, a particle size distribution algorithm yields regions of low flame retardant concentrationsa potential safety concernsand regions of excessively high flame retardant concentrationsa waste of an expensive product.
  09/2004;
• Source

  Available from: Julia Y Chan

  Article: High resolution three-dimensional visualization and characterization of coronary atherosclerosis in vitro by synchrotron radiation x-ray microtomography and highly localized x-ray diffraction.

  Hua Jin, Kyungmin Ham, Julia Y Chan, Leslie G Butler, Richard L Kurtz, Serigne Thiam, James W Robinson, Rezik A Agbaria, Isiah M Warner, Richard E Tracy
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  ABSTRACT: Human atherosclerotic plaques in both native and bypass arteries have been visualized using microtomography to provide additional information on the nature of coronary artery disease. Plaques contained within arteries removed from three white males aged 51, 55 and 70 are imaged in three-dimensions with monochromatic synchrotron x-ray radiation. Fields of view are 658 x 658 x 517 voxels. with cubic voxels ranging from 12 to 13 microm on a side. X-ray energies range from 11 to 15 keV (bandpass approximately 10 eV). At lower energies, high local absorption tends to generate reconstruction artefacts, while at higher energies the arterial wall is scarcely visible. At all energies, calcifications are clearly visible and differences are observed between plaques in native arteries (lifetime accumulations) versus bypass arteries (plaques developing in the interval between the heart bypass operation and the autopsy). In order to characterize coronary calcification, a microfocused, 50 microm2, 25 keV x-ray beam was used to acquire powder diffraction data from selected calcifications. Also, large calcifications were removed from the native arteries and imaged with 25 keV x-ray energy. Calcifications are composed of hydroxyapatite crystallites and an amorphous phase. In summary, native calcifications are larger and have a higher fraction of hydroxyapatite than calcifications from the bypass arteries.
  Physics in Medicine and Biology 01/2003; 47(24):4345-56. · 2.83 Impact Factor