Publications by authors named "Hermann Franz"

Purpose: Ocular autonomic control is mediated by sympathetic and parasympathetic nerve fibres. Their interactions are complemented by primary afferent nerve fibers of and intrinsic choroidal neurons (ICN). As the vasodilatative neuropeptide, vasoactive intestinal peptide (VIP), is expressed in extrinsic and intrinsic ocular neurons, it is of special interest in ophthalmic research.

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Powder X-ray diffraction techniques largely benefit from the superior beam quality provided by high-brilliance synchrotron light sources in terms of photon flux and angular resolution. The High Resolution Powder Diffraction Beamline P02.1 at the storage ring PETRA III (DESY, Hamburg, Germany) combines these strengths with the power of high-energy X-rays for materials research.

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Structural changes occurring in an Fe(72.5)Cu1Nb2Mo2Si(15.5)B7 alloy during a combination of constant rate heating (20 K min(-1)) and isothermal holding at 500 and 520 °C were investigated using in situ high-energy X-ray diffraction.

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Article Synopsis
  • A new hard X-ray delay line has been created to split and delay single X-ray pulses for advanced experiments like X-ray photon correlation spectroscopy (XPCS) at free-electron laser sources.
  • The device was tested using 8.39 keV synchrotron radiation, successfully demonstrating time delays of up to 2.95 ns.
  • The recorded static speckle patterns showed a speckle contrast of 56%, suggesting that the delay line can enable ultra-fast XPCS studies in the future.
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A prototype device capable of splitting an x-ray pulse into two adjustable fractions, delaying one of them with the aim to perform x-ray photon correlation spectroscopy and pump-probe type studies, was designed, manufactured, and tested. The device utilizes eight perfect silicon crystals in vertical 90 degrees scattering geometry. Its performance has been verified with 8.

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Atomic structures of amorphous Al(89)La(6)Ni(5), prepared by single-roller melt spinning, and pre-annealed at 493 and 588 K for 1 h, were characterized by differential scanning calorimetry, x-ray diffraction with a large wavevector transfer value, La L(3)-edge and Ni K-edge x-ray absorption fine structure and the reverse Monte Carlo technique. In the as-prepared amorphous alloy, our study reveals that the Ni-Al distance is 2.38 ± 0.

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