Several different charge transfer and Ce3+ localization scenarios for Rh–CeO2(111)

We present DFT+U based electronic structure calculations in a p(3x3) slab supercell, for low coverages of atomically dispersed Rh interacting with the CeO2(111) surface, comparing Rh as an adatom, and as a dopant substituted into the surface layer. We find that, energetically, a Rh atom approaching a ceria(111) surface with both sparse O and Ce vacancies present strongly prefers to heal the Ce vacancies, but next it prefers to adsorb on a stoichiometric region rather than healing an O vacancy. In the adatom system, Rh is oxidized by electron transfer to a 4f orbital on one Ce ion in the surface layer, which is then nominally converted from Ce4+ → Ce3+ (i.e. Rh adatoms are single donors). We show that there are a number of different local minima, with Ce3+ localization at 1st, 2nd or 3rd nearest neighbour Ce sites. The second neighbour is the most stable, but all are close in energy. In the Rh-doped system (Rh replaces Ce), Rh is oxidized by charge transfer to neighbouring O atoms, and Rh doping leads to deep acceptor and donor states. Rh is not stable in the O sublattice. Moreover, based on vacancy formation energies, we find that oxygen vacancy formation is strongly enhanced in the vicinity of Rh dopants, but slightly suppressed in the vicinity of Rh adatoms

The religionistic method in activities of the Society for the research of sects and new religious movements

Práce se zabývá analýzou činnosti Společnosti pro studium sekt a nových náboženských směrů, jako společnosti badatelsky působící na poli nové religiozity, s přihlédnutím k možné religionistické metodě v činnosti této společnosti. Dále se věnuje otázce religionistické metody a vymezením pojmů náboženství, sekta a nový náboženský směr.Katedra religionistiky a filozofieDokončená práce s úspěšnou obhajobo

Ontological-ontic Concept of Conditions and Prerequisites of Inauthentic Dasein Demonstrated by the Example of Inauthentic Work of Art

The thesis deals with the issue of authentic or inauthentic work of art in the context of philosophy of authentic / inauthentic mode of existence (Dasein) as it was developed by Martin Heidegger in his Time and Being. The reason for addressing this issue is an effort to open the possibility of understanding authenticity or inauthenticity of individual Dasein in the manner which grasps it in the act of its performance, i.e. as a singular event. Thinking of authentic / inauthentic work of art demonstrates the limits of approach which understands authenticity only as certain originality or "selfness" which should belong to something authentic or inauthentic, almost like its accident. This thesis is therefore concerned with what is revealed if the concept of authenticity is transposed to a work of art. Since it is the subject who can make the act of performance of authenticity happen, the author and the recipient of the authentic / inauthentic work of art are problematized as well. When dealing with the work of art with respect to its temporality (historicality) or its being, the thesis also provides room for the issue of perception of the work of art. The resemblance of the author and the recipient is thus revealed and so is the necessity to learn to see not only artworks as such but to see them...Předkládaná práce se zabývá otázkou autenticky resp. neautenticky uměleckého díla v kontextu myšlení autentického, resp. neautentického modu pobytu tak, jak téma autenticity rozvinul Martin Heidegger ve svém díle Bytí a čas. Důvodem pro tematizaci otázky je snaha otevřít možnost myslet autenticitu či neautenticitu pobytu způsobem uchopujícím ji v jejím výkonu, tj. jako událost, jíž je vlastní její významně ji náležející charakter. Myslet autenticky, resp. neautenticky umělecké dílo ukazuje na hranice přístupu vnímající autenticitu pouze ve smyslu jisté původnosti či "svojskosti", jež by měla "náležet" něčemu, co má být autentické či neautentické, téměř na způsob případku. Proto se práce věnuje tomu, co se ukáže, pokud je myšlení autenticity přeneseno na umělecké dílo. Protože tím, co "výkon" autenticity může vůbec založit, je subjekt, je při promýšlení neautenticky, resp. autenticky uměleckého díla problematizován i jeho autor a příjemce. Při zabývání se uměleckým dílem s ohledem na jeho časovost či např. bytnost je proto dán prostor i otázce vidění, resp. vnímání uměleckého díla. Přitom se ukazuje podobnost autora s příjemcem, ale rovněž i to, že je třeba se učit vidět (nejen) umělecká díla, ale především autentickým způsobem. Tím se téma obrací nazpět k otázce autentického pobytu, jinak tuto...Oddělení pro vědeckou činnostPedagogická fakultaFaculty of Educatio

Ontological-ontic Concept of Conditions and Prerequisites of Inauthentic Dasein Demonstrated by the Example of Inauthentic Work of Art

The thesis deals with the issue of authentic or inauthentic work of art in the context of philosophy of authentic / inauthentic mode of existence (Dasein) as it was developed by Martin Heidegger in his Time and Being. The reason for addressing this issue is an effort to open the possibility of understanding authenticity or inauthenticity of individual Dasein in the manner which grasps it in the act of its performance, i.e. as a singular event. Thinking of authentic / inauthentic work of art demonstrates the limits of approach which understands authenticity only as certain originality or "selfness" which should belong to something authentic or inauthentic, almost like its accident. This thesis is therefore concerned with what is revealed if the concept of authenticity is transposed to a work of art. Since it is the subject who can make the act of performance of authenticity happen, the author and the recipient of the authentic / inauthentic work of art are problematized as well. When dealing with the work of art with respect to its temporality (historicality) or its being, the thesis also provides room for the issue of perception of the work of art. The resemblance of the author and the recipient is thus revealed and so is the necessity to learn to see not only artworks as such but to see them..

Possible revision of the terms in the study of religion: example of "Cyber Religion"

Záměrem této práce je tázání se po možnosti revize religionistických pojmů na příkladu fenoménu cyber-religion, jakkoliv se tento fenomén může jevit nestálým, stejně jako se může jevit nestálé každé téma, uvozené prefixem cyber. Text se pokouší charakterizovat statut religionistiky v kulturní situaci, která se přibližuje postmodernímu způsobu pohledu, a to přes popis kyberprostoru (kyberkultury) a některých (kvazi)religiózních jevů s ním souvisejících, a to tak, aby bylo možné přes tyto výpovědi formulovat (nebo se pokusit formulovat) požadavky na religionistiku odtud plynoucí. Účelem práce pak není podat nějaké vyčerpávající odpovědět (nebo koneckonců: nutně jakoukoliv odpověď); text je spíše o způsobu hledání možnosti (nebo možností), jak se tušení případné odpovědi alespoň přiblížit.This diploma paper focuses on revison of basic concepts of religious studies. The core of the analyses is centered especially around the phenomenon of cyber-religion, however unstable this term – as well as any topic prefixed 'cyber' – is. The work strives to characterize the status of religous studies in cultural situation described as postmodern through utterances about cyberspace, other cyber-topics and certain related (quasi)religious phenomena. These charecteristics further serve as a foundation for attempts to formulate new requirements for religious studies. The work does not – and cannot – offer any ultimate answers or conclusions, it is rather a search for possibilities how to reveal anticipation of potential answers.Katedra religionistiky a filosofieDokončená práce s úspěšnou obhajobo

Examination of Oxygen Vacancy Formation in Mn-Doped CeO₂ (111) Using DFT+U and the Hybrid Functional HSE06

MnO_<i>x</i>–CeO_<i>x</i> mixed oxide systems exhibit interesting sulfur adsorption capacities and catalytic activity. We examined the electronic structure of Mn-doped fluorite CeO₂ bulk solid and surface using density functional theory (DFT) with the Hubbard <i>U</i> term or the Heyd–Scuseria–Ernzerhof (HSE06) hybrid functional. We specifically evaluate the reducibility and formation energies of Mn-doped CeO₂ surfaces. The use of a <i>U</i> value on the d-states of Mn is examined, and a value of 4 eV is chosen based upon results from DFT+U calculations on bulk MnO_<i>x</i>, XANES characterization of oxidation states in calcined and reduced Mn-doped CeO₂, and comparison with HSE06 hybrid functional results. Electronic structure impacts of the <i>U</i> inclusion are discussed. The concentration and orientation of Mn atoms doped into the surface of CeO₂ have a great influence on the reducibility of the surface. Based upon formation energies, Mn will not favor doping into the surface of CeO₂ in a fully oxidized system (Mn⁴⁺). Under reducing environments, Mn will dope into the surface with oxygen vacancies present (Mn³⁺ and Mn²⁺). The first oxygen vacancy is not likely catalytically important in fluorite MnO_<i>x</i>–CeO_<i>x</i> systems as formation of the fully oxidized surface is not stable. A greater degree of reduction would occur during a catalyzed redox reaction

Ce-Mn oxides for high-temperature gasifier effluent desulfurization

We examined Ce-Mn mixed oxides as high-temperature desulfurization materials, exploring various Mn/Ce ratios and the effects of admixing other rare earth oxides. The sulfur capacities at temperatures from 900 to 1025 K with simple air regeneration were measured for repeat cycles until a stable, reversible capacity was obtained. The measured sulfur capacities with a realistic model syngas containing H S, H , N , CO, H O, and CO were compared to thermodynamically possible maximum sulfur capacities. The oxidized and sulfided (reduced) sorbents were characterized by X-ray diffraction (XRD), X-ray absorption near-edge spectroscopy (XANES), X-ray absorption fine structure (XAFS), temperature-programmed reduction (TPR), and Brunauer-Emmett-Teller (BET) surface area. Density functional theory calculations are used to aid in interpreting characterization data and in explaining the enhanced S adsorption capacities. There is a large synergistic effect on sulfur adsorption and reaction resulting from the intimate admixing of Mn with CeO and CeO /La O rare earth oxides. However, while these materials are stable at temperatures near 900 K, even using air regeneration, the observed stable sulfur capacities fall far short of predictions based on thermodynamic equilibrium. The differences are attributed to (a) inhibition by CO and H O; (b) formation of some irreversible sulfates upon air regeneration; (c) inability of sulfur to diffuse into larger, sintered crystals of the mixed oxides; (d) gradual dissolution of Mn in an underlying support such as Al O (when present). © 2012 American Chemical Society. 2 2 2 2 2 2 2 2 3 2 2 2