1,829 research outputs found

    Exploration of Marine Resources by Photographic Remote Sensing

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    The interpretation of photographs in oceanographic remote sensing is discussed. The photographs were made from spacecraft with two exceptions. Two photographs were made from aircraft. There were three types of film used to make the photographs: black-and-white, color, and color IR. Black and white photography is well known; it presents pictures in various shades of gray from black to white. Color film presents pictures in color, very nearly as the human eye sees them. Color IR film presents pictures in color also but not as seen by the human eye. Blue becomes much deeper blue, green is suppressed to some extent, and red is recorded beyond the visual range of the human eye, out in the near infrared. The most noticeable effect of the use of color IR film is that leaf materials which are highly reflective in the infrared part of the spectrum are presented as red

    Topological Symmetry Groups of K_{4r+3}

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    We present the concept of the topological symmetry group as a way to analyze the symmetries of non-rigid molecules. Then we characterize all of the groups which can occur as the topological symmetry group of an embedding of the complete graph K_{4r+3} in S^3

    Self-Reported Energy Intake and Energy Expenditure in Elderly Women

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    The elderly are a growing population; however, limited information concerning energy requirements of the elderly is available. Dietary intake data have been collected in research and clinical settings to determine the intakes of energy and nutrients, but the accuracy of dietary intake data has been difficult to verify. Studies using doubly labeled water have suggested that dietary energy intake is underreported by obese subjects (1), adolescents (2), and athletes (3). Diet records were collected for 6 to 14 days in these studies (1), (2), (3). Elderly subjects have also underreported energy intake compared with total energy expenditure (TEE), either measured (4), (5), (6) or predicted (7). However, these studies only collected dietary data for 3 or 4 days, while energy expenditure was measured for 10 to 14 days using doubly labeled water. It is generally accepted that a major source of random variation in dietary energy can be ascribed to a person\u27s day-to-day variation in energy consumption, which averages 20% to 30% (8). This random variation decreases as the square root of the number of study days increases, such that it is approximately 10% for a 7-day record (9). Thus, some of the variability in self-reported energy intake may be attributable to the limited number of observations taken in previous studies of elderly women. To our knowledge, a comparison of TEE using doubly labeled water and concurrent diet records for a full week for elderly women has not been reported previously. The purpose of our study was to determine whether a complete recording of dietary intake would improve the accuracy of and reduce the individual variation in self-reported dietary energy intake compared with energy expenditure measurements using doubly labeled water

    On abstract commensurators of groups

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    We prove that the abstract commensurator of a nonabelian free group, an infinite surface group, or more generally of a group that splits appropriately over a cyclic subgroup, is not finitely generated. This applies in particular to all torsion-free word-hyperbolic groups with infinite outer automorphism group and abelianization of rank at least 2. We also construct a finitely generated, torsion-free group which can be mapped onto Z and which has a finitely generated commensurator.Comment: 13 pages, no figur

    Новий навчальний посібник “Україна в міжнародних організаціях”

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    Рецензія на посібник: Макар Ю. І. Україна в міжнародних організаціях : навч. посібник / Ю. І. Макар, Б. П. Гдичинський, В. Ю. Макар, С. Д. Попик, Н. Ю. Ротар ; за ред. Ю. І. Макара. – Чернівці : Прут, 2009. – 880 с

    Experimental Implementation of Discrete Time Quantum Random Walk on an NMR Quantum Information Processor

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    We present an experimental implementation of the coined discrete time quantum walk on a square using a three qubit liquid state nuclear magnetic resonance (NMR) quantum information processor (QIP). Contrary to its classical counterpart, we observe complete interference after certain steps and a periodicity in the evolution. Complete state tomography has been performed for each of the eight steps making a full period. The results have extremely high fidelity with the expected states and show clearly the effects of quantum interference in the walk. We also show and discuss the importance of choosing a molecule with a natural Hamiltonian well suited to NMR QIP by implementing the same algorithm on a second molecule. Finally, we show experimentally that decoherence after each step makes the statistics of the quantum walk tend to that of the classical random walk.Comment: revtex4, 8 pages, 6 figures, submitted to PR

    Nanostructures design by plasma afterglow-assisted oxidation of iron–copper thin films

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    International audienceOxidizing thin films made of Fe-Cu alloy with an Ar-O 2 micro-afterglow operated at atmospheric pressure shows remarkable growth processes. The presence of iron in copper up to about 50% leads to the synthesis of CuO nanostructures (nanowalls, nanotowers and nanowires). Nanotowers show the presence of an amorphous phase trapped between crystalline domains. Beyond 50%, Fe 2 O 3 iron nano-blades are also found. CuO nanowires as small as 5 nm in diameter can be synthesized. Thanks to the presence of patterned domains induced by buckling, it was possible to show that the stress level decreases when the iron content in the alloy increases. Iron blades grow from the inner Fe 2 O 3 layer through the overlying CuO if it is thin enough

    The resource theory of quantum reference frames: manipulations and monotones

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    Every restriction on quantum operations defines a resource theory, determining how quantum states that cannot be prepared under the restriction may be manipulated and used to circumvent the restriction. A superselection rule is a restriction that arises through the lack of a classical reference frame and the states that circumvent it (the resource) are quantum reference frames. We consider the resource theories that arise from three types of superselection rule, associated respectively with lacking: (i) a phase reference, (ii) a frame for chirality, and (iii) a frame for spatial orientation. Focussing on pure unipartite quantum states (and in some cases restricting our attention even further to subsets of these), we explore single-copy and asymptotic manipulations. In particular, we identify the necessary and sufficient conditions for a deterministic transformation between two resource states to be possible and, when these conditions are not met, the maximum probability with which the transformation can be achieved. We also determine when a particular transformation can be achieved reversibly in the limit of arbitrarily many copies and find the maximum rate of conversion. A comparison of the three resource theories demonstrates that the extent to which resources can be interconverted decreases as the strength of the restriction increases. Along the way, we introduce several measures of frameness and prove that these are monotonically nonincreasing under various classes of operations that are permitted by the superselection rule.Comment: 37 pages, 4 figures, Published Versio
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