925 resultados para supplementary elements


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We prove that under certain topological conditions on the set of universal elements of a continuous map T acting on a topological space X, that the direct sum T and M_g is universal, where M_g is multiplication by a generating element of a compact topological group. We use this result to characterize R_+-supercyclic operators and to show that whenever T is a supercyclic operator and z_1,...,z_n are pairwise different non-zero complex numbers, then the operator z_1T\oplus ... \oplus z_n T is cyclic. The latter answers affirmatively a question of Bayart and Matheron.

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The performance of a very low loss frequency selective surface (FSS) comprising two air spaced planar arrays of linear slot elements is reported. The beamsplitter generates a low loss passband response with a very sharp transmission roll-off with frequency. Simulated and measured results in the 30 GHz and 300 GHz wavebands are used to quantify the performance improvement compared to a conventional multilayer dielectrically backed conducting ring FSS. The paper also discusses the effect of the array dimensions on the passband width and filter roll-off rate.

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A method of injecting metallic elements into an electron-beam ion trap (EBIT) is described. The method is advantageous over the conventional coaxial and pulsed injection methods in two ways: (a) complicated switching of injection and extraction beams can be avoided when extracting beams of highly charged ions from the EBIT and (b) a beam of stable intensity can be achieved. This method may be applicable to any metallic elements or metallic compounds that have vapor pressures of similar to 0.1 Pa at a temperature lower than 1900 degrees C. We have employed this method for the extraction of highly charged ions of Bi, Er, Fe, and Ho. (c) 2006 American Institute of Physics.

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Sociological assertions of religious vitality in Euro-American societies have developed a paradigm of spirituality in which, following earlier studies of the New Age, a distinction is drawn between external authority and self-authority. Methodologically and theoretically problematic, this paradigm diverts attention from people’s social practices and interactions, especially in relation to multiple religious authorities. Drawing upon ethnographic fieldwork with an English religious network, and building upon the work of Pierre Bourdieu, this paper considers situations in which multiple authorities tend to relativize each other. Conceptualizing this in terms of nonformativeness - the lack of authorities’ abilities formatively to shape religious identity, habitus, and competition over religious capital - a new understanding of individual secularization emerges that questions assertions of vitality.

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An investigation of carbonation in mortars and methods of measuring the degree of carbonation and pH change is presented. The mortars were manufactured using ordinary portland cement, pulverized fuel ash, ground granulated blast-furnace slag, metakaolin, and microsilica. The mortars were exposed to a carbon dioxide-rich environment 5% CO2 to accelerate carbonation. The resulting carbonation was measured using phenolphthalein indicator and thermogravimetric analysis. The pH of the pore fluid and a powdered sample, extracted from the mortar, was measured to give an accurate indication of the actual pH of the concrete. The pH of the extracted powder mortar sample was found to be similar to the pH of the pore fluid expressed from the mortars. The thermogravimetric analysis suggested two distinct regions of transport of CO2 within mortar, a surface region where convection was prevalent and a deeper region where diffusion was dominant. The use of microsilica has been shown to decrease the rate of carbonation, while pulverized fuel ash and ground granulated blast-furnace slag have a detrimental effect on carbonation. Metakaolin has little effect on carbonation.

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The goal of this study is to identify cues for the cognitive process of attention in ancient Greek art, aiming to find confirmation of its possible use by ancient Greek audiences and artists. Evidence of cues that trigger attention’s psychological dispositions was searched through content analysis of image reproductions of ancient Greek sculpture and fine vase painting from the archaic to the Hellenistic period - ca. 7th -1st cent. BC. Through this analysis, it was possible to observe the presence of cues that trigger orientation to the work of art (i.e. amplification, contrast, emotional salience, simplification, symmetry), of a cue that triggers a disseminate attention to the parts of the work (i.e. distribution of elements) and of cues that activate selective attention to specific elements in the work of art (i.e. contrast of elements, salient color, central positioning of elements, composition regarding the flow of elements and significant objects). Results support the universality of those dispositions, probably connected with basic competencies that are hard-wired in the nervous system and in the cognitive processes.