Modeling ESA's TT/C systems

After a brief introduction on the need for simulation packages for the analysis and design of satellite communications systems, the software tool developed for the European Space Agency (ESA), its main objectives and the design choices made during the development are presented. A very concise description of the available communications and measurement block follows. The ESA standard Telemetry, Tracking and Command (TT&C) system simulator is then introduced along with a description of the ESA standard modulation and coding schemes. As an example, the simulation of the ranging system which is a non-standard communications block, is described in details. Several examples of TT&C simulations outputs are given and compared with measurement results or theoretical approximations, when available. Finally, future developments like the support of advanced modulation schemes and the dynamic satellite link simulation are presented

A Comparative Study of Two Albanian Post-Byzantine Icons Attributed to Simoni i Ardenices

Aims: The present study is part of a project concerning the characterisation of a limited number of selected Albanian Byzantine and post-Byzantine icons, through the identification of pigments, of painting technique and the state of conservation of the artworks. The Albanian iconographers produced an extraordinary amount of icons from the 14th till the 19th century, and over six thousand of them are kept in the Museum of Medieval Art of Korça (Albania). This paper refers to the results obtained in the study of two artworks, the first one by Simoni i Ardenices an important Albanian painter of XVII century, and the second one attributed to him. Study Design: The present work is part of a more general study concerning Albanian Byzantine and post-Byzantine icons. Place and Duration of Study: Museum of Medieval Art of Korça, Albania, between June 2008 and July 2009. Methodology: The work was conducted by non-destructive methods, X-ray fluorescence, visible light reflectance spectrophotometry and UV fluorescence analysis, according to a systematic procedure developed in the same Chemical Physical Laboratory for Cultural Heritage. A number of areas, for each painting, were chosen in order to carry out the measurements. With this procedure, we could identify the inorganic pigments from their characteristic features. Moreover, the study of the chemical physical properties of paintings is of fundamental importance for any accurate restoration intervention. Results and Conclusion: The present work, concerning the study of two icons of the second half of 17th century by Simoni i Ardenices, has allowed us to identify the painting technique and the palette used in these works of art. Moreover, the areas of the paintings in which old restorations have been made have also been identified

Effect of randomizers on the power spectrum excess of space telemetry signals

none6siThis paper presents a thorough analysis of the spectral characteristics of space telemetry signals when randomizers are used to counter the power excess, that is, the increase of the power spectrum in some measurement bandwidths with respect to the transmission of an ideal random signal. We show that a long randomizer actually improves the spectral characteristics but is not able to solve some critical problems appearing when all-zero frames or almost constant data are transmitted. Suitable solutions are proposed to face these cases, ensuring a small power excess in all possible operation conditions. The impact of high-order modulations and error correcting codes is also investigated.openMassimo Battaglioni, Marco Baldi, Franco Chiaraluce, Roberto Garello, Enrico Vassallo, Gian Paolo CalzolariBattaglioni, Massimo; Baldi, Marco; Chiaraluce, Franco; Garello, Roberto; Vassallo, Enrico; Paolo Calzolari, Gia

Growth and Physical Structure of Amorphous Boron Carbide Deposited by Magnetron Sputtering on a Silicon Substrate with a Titanium Interlayer

Multilayer amorphous boron carbide coatings were produced by radiofrequency magnetron sputtering on silicon substrates. To improve the adhesion, titanium interlayers with different thickness were interposed between the substrate and the coating. Above three hundreds nanometer, the enhanced roughness of the titanium led to the growth of an amorphous boron carbide with a dense and continuing columnar structure, and no delamination effect was observed. Correspondingly, the adhesion of the coating became three time stronger than in the case of a bare silicon substrate. Physical structure and microstructural proprieties of the coatings were investigated by means of a scan electron microscopy, atomic force microscopy and X-ray diffraction. The adhesion of the films was measured by a scratch tester

Growth and Physical Structure of Amorphous Boron Carbide Deposited by Magnetron Sputtering on a Silicon Substrate with a Titanium Interlayer

Multilayer amorphous boron carbide coatings were produced by radiofrequency magnetron sputtering on silicon substrates. To improve the adhesion, titanium interlayers with different thickness were interposed between the substrate and the coating. Above three hundreds nanometer, the enhanced roughness of the titanium led to the growth of an amorphous boron carbide with a dense and continuing columnar structure, and no delamination effect was observed. Correspondingly, the adhesion of the coating became three time stronger than in the case of a bare silicon substrate. Physical structure and microstructural proprieties of the coatings were investigated by means of a scan electron microscopy, atomic force microscopy and X-ray diffraction. The adhesion of the films was measured by a scratch tester

MAVIS: system modelling and performance prediction

The MCAO Assisted Visible Imager and Spectrograph (MAVIS) Adaptive Optics Module has very demanding goals to support science in the optical: providing 15% SR in V band on a large FoV of 30arcsec diameter in standard atmospheric conditions at Paranal. It will be able to work in closed loop on up to three natural guide stars down to H=19, providing a sky coverage larger than 50% in the south galactic pole. Such goals and the exploration of a large MCAO system parameters space have required a combination of analytical and end- to-end simulations to assess performance, sky coverage and drive the design. In this work we report baseline performance, statistical sky coverage and parameters sensitivity analysis done in the phase-A instrument study.Comment: 12 pages, 9 figures, 7 tables. SPIE conference Astronomical Telescopes and Instrumentation, 14 - 18 December 2020, digital foru

Eosinophilic Pneumonia Associated with Rheumatoid Arthritis: Description of a Case Report and Review of the Literature

Rheumatoid arthritis (RA), a systemic inflammatory disease, may induce pulmonary manifestations. We describe a case of longstanding RA presenting with eosinophilic pneumonia (EP). Rare case reports of tissue eosinophilia involving isolated organs in the setting of RA exist in the literature. It has been shown that the production of proinflammatory cytokines activates different cell group and can simultaneously play a role in RA and induce eosinophils infiltration in target tissue. An appropriate lowest possible dosage of steroid therapy is essential, whereas EP may be a rare subset of pulmonary involvement in RA