Autor: Martin, Alice - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Modelling interactive computing systems: Do we have a good theory of what computers are?
Autorzy:: Martin, Alice
Magnaudet, Mathieu
Conversy, Stéphane
Tematy:: philosophy of computing
models of computation
interactive computing
computing mechanism
computational mechanistic explanation; Pokaż więcej
Wydawca:: Copernicus Center Press
Powiązania:: https://bibliotekanauki.pl/articles/31804107.pdf Link otwiera się w nowym oknie
Opis:: Computers are increasingly interactive. They are no more transformational systems producing a final output after a finite execution. Instead, they continuously react in time to external events that modify the course of computing execution. While philosophers have been interested in conceptualizing computers for a long time, they seem to have paid little attention to the specificities of interactive computing. We propose to tackle this issue by surveying the literature in theoretical computer science, where one can find explicit proposals for a model of interactive computing. In that field, the formal modelling of interactive computing systems has been brought down to whether the new interaction models are reducible to Turing Machines. There are three areas where interaction models are framed. The comparison between TMs and interactive system models is at stake in all of them. These areas are namely some works on concurrency by Milner, on Reactive Turing Machines, and on interaction as a new computing paradigm. For each of the three identified models, we present its motivation, sum up its account for interaction and its legacy, and point out issues regarding the understanding of computers. The survey shows difficulties for epistemologists. The reason is that these analyses focus on the formal equivalence between interactive models of computation and classic ones. Such a project is different from addressing how a computing machine can be interactive: in other words, which mechanisms allow it.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Preparation, characterization and photocatalytic properties of cerium doped $TiO_{2}$ : on the effect of Ce loading on the photocatalytic reduction of carbon dioxide
Autorzy:: Kotarba, Andrzej
Matěj, Zdeněk
Matějová, Lenka
Wach, Anna
Obalová, Lucie
Hospodková, Alice
Čapek, Libor
Reli, Martin
Kočí, Kamila
Peikertová, Pavlína
Kuśtrowski, Piotr
Opis:: The parent TiO 2 and cerium doped TiO 2 photocatalysts with Ce loadings 0.28–10 mol.% were prepared by the sol-gel method controlled within reverse micelles of nonionic surfactant Triton X-114. Photocatalysts were comprehensively characterized using nitrogen physisorption, XRD, XPS, contact potential difference measurements, Raman spectroscopy, and DR UV–vis spectroscopy and their performance was explored in the CO 2 photocatalytic reduction for the first time. Concerning photocatalysts properties, it was revealed that the inhibiting effect of cerium on the TiO 2 crystallites growth occurred only up to 3 mol.% of Ce when the incorporation of Ce 4+ into the anatase lattice took place. This phenomenon was correlated with the expansion of anatase cell volume. At higher Ce loadings ( ≥ 5 mol.%) the anatase lattice was saturated and the formation/separation of amorphous ceria and/or ceria ( ∼ 1 nm) nucleation occurred, accompanied by the increase of TiO 2 anatase crystallite-size and the limitation of value of anatase cell volume. Fur- ther, it was found out that the mesoporosity of photocatalysts may be preferentially attributed to voids existing between the individual crystallites and thus can be influenced by changes in the crystallite size. The modification of TiO 2 with cerium affected also the spectral response of photocatalysts, shifting it to the visible light region. However, this property itself was not crucial in the CO 2 photocatalytic reduc- tion. The key role in the CO 2 photocatalytic reduction played the energies of electrons and holes within the electronic structure of photocatalysts, which were markedly affected by the Ce atoms addition. For 0.28 mol.%Ce/TiO 2 , both electrons and holes have required potentials for the photocatalytic reduction of CO 2 , while for 3 mol.% and higher Ce loadings the energy of electrons was already below H + reduction potential and thus the photocatalytic performance of these catalysts was decreasing.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego