Search results for " Mirror"
showing 10 items of 71 documents
Issues Related to the Restoration of Mirrors of the Wooden paliotto della chiesa del Santissimo Crocifisso all’Albergheria, Sicily (Italy)
2017
ABSTRACTIn this work, the decision-making process involved in the restoration of the eighteenth century paliotto ligneo (wooden altar frontal) della chiesa del Santissimo Crocifisso all’Albergheria of Palermo is presented. Earlier research concerning mirror restoration was based on only a few case studies and the proposed techniques were not suitable for the artwork here. As a consequence, it was necessary to re-examine theories and protocols of modern restoration to plan an appropriate intervention of the altar frontal. Since in this artwork the role of mirrors is not to give back images, as usual, but rather to create special light effects and play of lights, this work aims to find an app…
Drifts in real-time partial wavefront correction and how to avoid them
2017
In visual experiments that require real-time partial correction of wavefront aberrations, small errors occur that accumulate over time and lead to drifts in Zernike coefficients of the uncorrected aberrations. A simple algorithm that does not require the inclusion of an additional optical path to obtain independent measurements of the eye's aberrations is described here, and its effectiveness in preventing these drifts is demonstrated.
Astronomical soft x-ray mirrors reflectivity enhancement by multilayer coatings with carbon overcoating
2004
A number of X-ray astronomical missions of near future will make use of hard X-ray optics with broad-band multilayer coatings. However multilayer mirrors can be also useful to enhance the effective area of a given X-ray telescope in the "classical" low energy X-ray band (0.1 – 10 keV), the window where X-ray spectroscopy provides very useful plasma diagnostics) with a consistent gain with respect to usual single-layer reflectors. Multilayers for soft X-rays are based on stacks with constant d-spacing (in order to minimize the loss due to the photoelectric effect). A further gain in reflectivity (however only restricted to the energy range between 0.5 and 4 keV) can be achieved by using a lo…
Disabilità visiva e neuroni specchio
2009
Il seguente lavoro ha come obiettivo quello indagare, il possibile coinvolgimento del sistema dei neuroni specchio nella disabilità visiva, cercando di analizzare, in particolare, come il soggetto non vedente possa comprendere e conoscere l’azione degli altri privato dal corpus di informazioni provenienti dal canale visivo. L’ipotesi da verificare è se nei soggetti con disabilità visiva e nei soggetti con sviluppo tipico venga messo in gioco e con quale modalità, lo stesso sistema di neuroni specchio unitario (visivo-uditivo) per il riconoscimento dell’azione. Inoltre, lo studio dovrebbe consentire di verificare se la disabilità visiva ad esordio precoce (congenita) è in grado di aumentare …
L’ADULTO COME SPECCHIO. MODALITÀ COMUNICATIVE E APPRENDIMENTO
2021
Numerose ricerche sull’infanzia condotte a partire dal secolo scorso, hanno mostrato come i bambini, fin dai primi mesi di vita, siano attivi e propositivi nella interazione con gli altri esseri umani. In una prospettiva educativa, di promozione dei processi di apprendimento e di sostegno alla costruzione di una immagine di sé positiva e fiduciosa nelle proprie potenzialità, sono di grande importanza le modalità comunicative e relazionali degli adulti significativi. A tali modalità farò riferimento nel mio contributo, soffermandomi sul rispecchiamento verbale e non verbale, nelle sue diverse forme, approfondendone le ragioni teoriche e metodologiche e riflettendo su come possa attuarsi una …
Applications of Virtualization in Systems Design
2012
Experimental evidence on microwave induced electron losses from ECRIS plasma
2018
The balance between warm and hot (>1 keV) electron density and their losses from the magnetic confinement system of an Electron Cyclotron Resonance Ion Source (ECRIS) plasma is considered to be one of the main factors determining the rate of the high charge state ion production. One of the key loss channels for heated electrons is thought to be induced by the injected microwaves. While this loss mechanism, referred to as rf-induced pitch angle scattering, has been studied theoretically and with computational tools, direct experimental evidence of its significance in minimum-B ECRIS plasmas remains limited. In this work, experimental evidence of microwave induced electron losses in the axial…
Influence of axial mirror ratios on the kinetic instability threshold in electron cyclotron resonance ion source plasma
2022
International audience; Electron Cyclotron Resonance (ECR) ion source plasmas are prone to kinetic instabilities. The onset of the instabilities manifests as emission of microwaves, bursts of electrons expelled from the plasma volume, and the collapse of the extracted highly charged ion (HCI) currents. Consequently, the instabilities limit the HCI performance of ECR ion sources by limiting the parameter space available for ion source optimization. Previous studies have shown that the transition from stable to unstable plasma regime is strongly influenced by the magnetic field structure, especially the minimum field value inside the magnetic trap (Bmin). This work focuses to study the role o…
Single Event Transients and Pulse Quenching Effects in Bandgap Reference Topologies for Space Applications
2016
An architectural performance comparison of bandgap voltage reference variants, designed in a $0.18~\mu \text {m}$ CMOS process, is performed with respect to single event transients. These are commonly induced in microelectronics in the space radiation environment. Heavy ion tests (Silicon, Krypton, Xenon) are used to explore the analog single-event transients and have revealed pulse quenching mechanisms in analogue circuits. The different topologies are compared, in terms of cross-section, pulse duration and pulse amplitude. The measured results, and the explanations behind the findings, reveal important guidelines for designing analog integrated circuits, which are intended for space appli…
Miles pauperculus bohaterem zwierciadeł Fabiana Birkowskiego
2018
The subject of the article, which makes reference to pugna spiritualis - the topos that was popular in the old literature and to speculum - the characteristic form of writing in the 16* century, is discussed on the basis of selected sermons by Fabian Birkowski (devoted to annual holidays) and his Latin orations about saints. The model of knighthood that was defined by the baroque preacher as miles pauperculus is presented through the biographies of holly monks. The mirror-like character of Birkowski’s sermons makes not only the question of referring to a determined tradition of a literary form and its creative continuation (present also in the author’s funeral orations), but making use of t…