10,483 research outputs found

    Correlation between Cu ion migration behaviour and deNO x activity in Cu-SSZ-13 for the standard NH 3 -SCR reaction

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    Here we present the results of a synchrotron-based in situ, time-resolved PXRD study during activation of two Cu-SSZ-13 catalysts under O2/He and one during standard NH3-SCR reaction conditions to obtain insight into the behaviour of Cu ions. The results obtained indicate that deNOx activity is inexorably linked with occupancy of the zeolite 6r

    Стилістичні особливості хорових творів для дітей Б. Фільц на канонічні тексти

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    Авторка пропонованої читачам статті звертається до творів канонічної тематики відомої української композиторки Б. Фільц, досліджуючи особливості її авторської стилістики в аспекті виявлення співвідношень оригінальних та традиційних чинників, особливостей формотворення та циклічної драматургії.Автор предлагаемой читателям статьи исследует особенности авторской стилистики в аспекте выявления соотношений между оригинальными и традиционными факторами, особенностями формообразования, циклической драматургии.The author of the article, proposed to the readers, turns her attention to the works of the canonical thematics by the famous Ukrainian composer B. Filts, investigating the special features of her stylistics in the aspect of development of the relationships between the original and traditional factors, the special features of the forming and cyclic dramaturgy

    Patterns of Individual Shopping Behavior

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    Much of economic theory is built on observations of aggregate, rather than individual, behavior. Here, we present novel findings on human shopping patterns at the resolution of a single purchase. Our results suggest that much of our seemingly elective activity is actually driven by simple routines. While the interleaving of shopping events creates randomness at the small scale, on the whole consumer behavior is largely predictable. We also examine income-dependent differences in how people shop, and find that wealthy individuals are more likely to bundle shopping trips. These results validate previous work on mobility from cell phone data, while describing the unpredictability of behavior at higher resolution.Comment: 4 pages, 5 figure

    Characterization of growth and metabolism of the haloalkaliphile Natronomonas pharaonis

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    Natronomonas pharaonis is an archaeon adapted to two extreme conditions: high salt concentration and alkaline pH. It has become one of the model organisms for the study of extremophilic life. Here, we present a genome-scale, manually curated metabolic reconstruction for the microorganism. The reconstruction itself represents a knowledge base of the haloalkaliphile's metabolism and, as such, would greatly assist further investigations on archaeal pathways. In addition, we experimentally determined several parameters relevant to growth, including a characterization of the biomass composition and a quantification of carbon and oxygen consumption. Using the metabolic reconstruction and the experimental data, we formulated a constraints-based model which we used to analyze the behavior of the archaeon when grown on a single carbon source. Results of the analysis include the finding that Natronomonas pharaonis, when grown aerobically on acetate, uses a carbon to oxygen consumption ratio that is theoretically near-optimal with respect to growth and energy production. This supports the hypothesis that, under simple conditions, the microorganism optimizes its metabolism with respect to the two objectives. We also found that the archaeon has a very low carbon efficiency of only about 35%. This inefficiency is probably due to a very low P/O ratio as well as to the other difficulties posed by its extreme environment

    Operando Spectroscopic Studies of Cu–SSZ-13 for NH3–SCR deNOx Investigates the Role of NH3 in Observed Cu(II) Reduction at High NO Conversions

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    The small pore zeolite chabazite (SSZ-13) in the copper exchanged form is a very efficient material for the selective catalytic reduction by ammonia (NH 3 ) of nitrogen oxides (NOx) from the exhaust of lean burn engines, typically diesel powered vehicles. The full mechanism occurring during the NH 3 –SCR process is currently debated with outstanding questions including the nature and role of the catalytically active sites. Time-resolved operando spectroscopic techniques have been used to provide new level of insights in to the mechanism of NH 3 –SCR, to show that the origin of stable Cu(I) species under SCR conditions is potentially caused by an interaction between NH 3 and the Cu cations located in eight ring sites of the bulk of the zeolite and is independent of the NH 3 –SCR of NOx occurring at Cu six ring sites within the zeolite

    Variability and origin of seismic anisotropy across eastern Canada: evidence from shear-wave splitting measurements

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    Measurements of seismic anisotropy in continental regions are frequently interpreted with respect to past tectonic processes, preserved in the lithosphere as “fossil” fabrics. Models of the present-day sublithospheric flow (often using absolute plate motion as a proxy) are also used to explain the observations. Discriminating between these different sources of seismic anisotropy is particularly challenging beneath shields, whose thick (≥200 km) lithospheric roots may record a protracted history of deformation and strongly influence underlying mantle flow. Eastern Canada, where the geological record spans ∼3 Ga of Earth history, is an ideal region to address this issue. We use shear wave splitting measurements of core phases such as SKS to define upper mantle anisotropy using the orientation of the fast-polarization direction ϕ and delay time δt between fast and slow shear wave arrivals. Comparison with structural trends in surface geology and aeromagnetic data helps to determine the contribution of fossil lithospheric fabrics to the anisotropy. We also assess the influence of sublithospheric mantle flow via flow directions derived from global geodynamic models. Fast-polarization orientations are generally ENE-WSW to ESE-WNW across the region, but significant lateral variability in splitting parameters on a ≤100 km scale implies a lithospheric contribution to the results. Correlations with structural geologic and magnetic trends are not ubiquitous, however, nor are correlations with geodynamically predicted mantle flow directions. We therefore consider that the splitting parameters likely record a combination of the present-day mantle flow and older lithospheric fabrics. Consideration of both sources of anisotropy is critical in shield regions when interpreting splitting observations

    Rectangular Wilson Loops at Large N

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    This work is about pure Yang-Mills theory in four Euclidean dimensions with gauge group SU(N). We study rectangular smeared Wilson loops on the lattice at large N and relatively close to the large-N transition point in their eigenvalue density. We show that the string tension can be extracted from these loops but their dependence on shape differs from the asymptotic prediction of effective string theory.Comment: 47 pages, 21 figures, 8 table
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