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No problem is ever permanently closed. The editor is always pleased to consider for publication new solutions or new insights o n p a s t p r oblems. (1) Determine the set of all c > 0 such that whenever (1) holds, then we have x + y + z xy + yz+ zx. The positive r eals c asked for are those satisfying c 4. From (1), we have xy < c and z = c ; xy x + y + xy. Substituting this value of z into th...

The non-resonant magnetic X-ray scattering cross-section for photon energies up to 500 keV

– Results of high-energy magnetic X-ray diffraction for photon energies up to 500 keV are presented and the form of the magnetic scattering cross-section for relativistic energies is discussed. At 300 keV we experimentally proved that the scattering from the spin component perpendicular to the scattering plane is dominant. Within our statistical and systematic errors, the magnetic scattering am...

Stent-assisted coiling in endovascular treatment of 500 consecutive cerebral aneurysms with long-term follow-up.

BACKGROUND AND PURPOSE Stent-assisted coil embolization has become one of the most preferred techniques in the treatment of wide-neck intracranial aneurysms; however, long-term patency and safety of the self-expanding neurostents and their role in durability of the endovascular treatment has remained ambiguous. We sought to retrospectively examine the long-term results of self-expanding stent u...

High dynamic range test-bed for characterization of analog-to-digital converters up to 500 MSPS

A measurement set-up of for the characterization of analog-to-digital converters (ADCs) is described. The measurement set-up characterizes ADCs up to 16 bits at 350 MHz (option for >500 MHz). Testing dynamic performance of high-speed ADCs is regarded as difficult and expensive. By using existing state-of-the-art instruments in combination with specially designed amplifiers and filters, a high p...

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