46 research outputs found
Investigation of Deuterium Permeability of Sputtered Beryllium and Graded Copper-Doped Beryllium Shells
Southern African Large Telescope Spectroscopy of BL Lacs for the CTA project
In the last two decades, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic, by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about 40% of the more than 200 sources detected at very high energies with ground-based telescopes, the majority of which are blazars, i.e. their jets are closely aligned with the line of sight to Earth and three quarters of which are classified as high-frequency peaked BL Lac objects. One challenge to studies of the cosmological evolution of BL Lacs is the difficulty of obtaining redshifts from their nearly featureless, continuum-dominated spectra. It is expected that a significant fraction of the AGN to be detected with the future Cherenkov Telescope Array (CTA) observatory will have no spectroscopic redshifts, compromising the reliability of BL Lac population studies, particularly of their cosmic evolution. We started an effort in 2019 to measure the redshifts of a large fraction of the AGN that are likely to be detected with CTA, using the Southern African Large Telescope (SALT). In this contribution, we present two results from an on-going SALT program focused on the determination of BL Lac object redshifts that will be relevant for the CTA observatory
Nanoscratch test — A tool for evaluation of cohesive and adhesive properties of thin films and coatings
Thin films and coatings play an essential role in the whole range of applications. The
example par excellence are optical thin films that broaden the possibilities of design of
optical components. Analogically to other applications of thin films their mechanical
properties are very important for their successful applicability and reliability. This
becomes especially vital when they are employed in rough service conditions. As thin films
on substrates inherently create a compact system the strength of the film-substrate
interface is of great importance. Several experimental methods have been developed for
qualification and quantification of the mechanical stability of the film-substrate system.
In this paper, some brief introduction into the nanoscratch test is introduced. It is
currently the most widely used method to evaluate and to test cohesive-adhesive properties
of thin films and coatings
Comparison of eigenvalues for lidstone boundary value problems on a measure chain (preprint)
Investigation of TA frain boundary diffusion in copper by means of Auger electron spectroscopy
újratöltve - BIBFORM00866