3,915 research outputs found

    Generalized Elliptic Integrals and the Legendre M-function

    Get PDF
    We study monotonicity and convexity properties of functions arising in the theory of elliptic integrals, and in particular in the case of a Schwarz-Christoffel conformal mapping from a half-plane to a trapezoid. We obtain sharp monotonicity and convexity results for combinations of these functions, as well as functional inequalities and a linearization property.Comment: 28 page

    Structural and magnetic properties of MSr2Y1.5Ce0.5Cu2Oz (M-1222) compounds with M = Fe and Co

    Get PDF
    MSr2Y1.5Ce0.5Cu2Oz (M-1222) compounds, with M = Fe and Co, have been synthesized through a solid-state reaction route. Both compounds crystallize in a tetragonal structure (space group I4/mmm). A Rietveld structural refinement of room-temperature neutron diffraction data for Fe-1222 reveals that nearly half the Fe remains at the M site, while the other half goes to the Cu site in the CuO2 planes. Existence of Fe at two different lattice sites, is also confirmed by 57Fe Mossbauer spectroscopy from which it is inferred that nearly 50% of the total Fe occupies the Cu site in the CuO2 planes as Fe3+, whereas the other 50 % is located at the M site with nearly 40 % as Fe4+ and around 10% as Fe3+. For the M = Co compound, nearly 84 % of Co remains at its designated M site, while the rest occupies the Cu site in the CuO2 planes. The oxygen content, z, based on oxygen occupancies refined from the neutron diffraction data, comes close to 9.0 for both the samples The ZFC and FC magnetization curves as a function of temperature show a complex behavior for both Fe-1222 and Co-1222 compounds.Comment: MMM Inter mag Proceedings, accepted in J. Appl. Phy

    Ultrasonically assisted atmospheric freeze-drying of button mushroom. Drying kinetics and product quality

    Full text link
    This is an Author's Accepted Manuscript of an article published in Drying Technology, 36, 15, 1814-1823 © Taylor & Francis, available online at: http://doi.org/10.1080/07373937.2017.1417870[EN] The aim of this work was to evaluate the feasibility of using power ultrasound to improve the atmospheric freeze-drying of mushroom, as interesting alternative to vacuum freeze-drying, considering not only kinetic effects but also the final quality. For that purpose, mushroom slices (Agaricus bisporus) were dried (¿10°C and 2 m/s) with (24.6 and 12.3 kW/m3; 21.9 kHz) and without ultrasound application. The application of ultrasound significantly influenced the drying kinetics, increasing the effective diffusivity up to 280% and shortening drying time up to 74%. As for the quality parameters (color, texture, rehydration, and cell damage), no remarkable influence of the ultrasound application was observed. Therefore, the application of power ultrasound during the atmospheric freeze-drying of mushroom might be considered as an interesting technology providing that it significantly increased the process kinetics without greatly affecting the quality of the final product.The authors acknowledge the financial support of the Generalitat Valenciana (PROMETEOII/2014/005) and INIA-ERDF (RTA2015-00060-C04-02).Carrion, C.; Mulet Pons, A.; García Pérez, JV.; Cårcel Carrión, JA. (2017). Ultrasonically assisted atmospheric freeze-drying of button mushroom. Drying kinetics and product quality. Drying Technology. 36(15):1814-1823. https://doi.org/10.1080/07373937.2017.1417870S18141823361

    Structural and Magnetic Properties of MrSr₂Y₁.₅Ce₀.₅Cu₂Oz (M-1222) Compounds with M = Fe and Co

    Get PDF
    The MSr2Y1.5Ce0.5Cu2Oz (M-1222) compounds, with M = Fe and Co, have been synthesized through a solid-state reaction route. Both compounds crystallize in a tetragonal structure (space group 14/mmm). A Rietveld structural refinement of the room-temperature neutron diffraction data for Fe-1222 reveals that nearly half the Fe remains at the M site, while the other half goes to the Cu site in the CuO2 planes. Existence of Fe at two different lattice sites is also confirmed by 57Fe Mössbauer spectroscopy from which it is inferred that ~50% of the total Fe occupies the Cu site in the CuO2 planes as Fe3+, whereas the other ~50% is located at the M site with ~40% as Fe4+ and ~10% as Fe3+. For the M[Double Bond]Co compound, nearly 84% of Co remains at its designated M site, while the rest occupies the Cu site in the CuO2 planes

    Stress Impairs Skin Barrier Function and Induces α2-3 Linked N-Acetylneuraminic Acid and Core 1 O-Glycans on Skin Mucins in Atlantic Salmon, Salmo salar

    Get PDF
    The skin barrier consists of mucus, primarily comprising highly glycosylated mucins, and the epithelium. Host mucin glycosylation governs interactions with pathogens and stress is associated with impaired epithelial barrier function. We characterized Atlantic salmon skin barrier function during chronic stress (high density) and mucin O-glycosylation changes in response to acute and chronic stress. Fish held at low (LD: 14–30 kg/m3) and high densities (HD: 50-80 kg/m3) were subjected to acute stress 24 h before sampling at 17 and 21 weeks after start of the experiment. Blood parameters indicated primary and secondary stress responses at both sampling points. At the second sampling, skin barrier function towards molecules was reduced in the HD compared to the LD group (Papp mannitol; p < 0.01). Liquid chromatography–mass spectrometry revealed 81 O-glycan structures from the skin. Fish subjected to both chronic and acute stress had an increased proportion of large O-glycan structures. Overall, four of the O-glycan changes have potential as indicators of stress, especially for the combined chronic and acute stress. Stress thus impairs skin barrier function and induces glycosylation changes, which have potential to both affect interactions with pathogens and serve as stress indicators. View Full-TextpublishedVersio

    Muc2-dependent microbial colonization of the jejunal mucus layer is diet sensitive and confers local resistance to enteric pathogen infection.

    Get PDF
    Intestinal mucus barriers normally prevent microbial infections but are sensitive to diet-dependent changes in the luminal environment. Here we demonstrate that mice fed a Western-style diet (WSD) suffer regiospecific failure of the mucus barrier in the small intestinal jejunum caused by diet-induced mucus aggregation. Mucus barrier disruption due to either WSD exposure or chromosomal Muc2 deletion results in collapse of the commensal jejunal microbiota, which in turn sensitizes mice to atypical jejunal colonization by the enteric pathogen Citrobacter rodentium. We illustrate the jejunal mucus layer as a microbial habitat, and link the regiospecific mucus dependency of the microbiota to distinctive properties of the jejunal niche. Together, our data demonstrate a symbiotic mucus-microbiota relationship that normally prevents jejunal pathogen colonization, but is highly sensitive to disruption by exposure to a WSD

    Bonn Potential and Shell-Model Calculations for 206,205,204Pb

    Get PDF
    The structure of the nuclei 206,205,204Pb is studied interms of shell model employing a realistic effective interaction derived from the Bonn A nucleon-nucleon potential. The energy spectra, binding energies and electromagnetic properties are calculated and compared with experiment. A very good overall agreement is obtained. This evidences the reliability of our realistic effective interaction and encourages use of modern realistic potentials in shell-model calculations for heavy-mass nuclei.Comment: 4 pages, 4 figures, submitted to Physical Review

    Use of near infrared reflectance spectroscopy to predict nitrogen uptake by winter wheat within fields with high variability in organic matter

    Get PDF
    In this study, the ability to predict N-uptake in winter wheat crops using NIR-spectroscopy on soil samples was evaluated. Soil samples were taken in unfertilized plots in one winter wheat field during three years (1997-1999) and in another winter wheat field nearby in one year (2000). Soil samples were analyzed for organic C content and their NIR-spectra. N-uptake was measured as total N-content in aboveground plant materials at harvest. Models calibrated to predict N-uptake were internally cross validated and validated across years and across fields. Cross-validated calibrations predicted N-uptake with an average error of 12.1 to 15.4 kg N ha-1. The standard deviation divided by this error (RPD) ranged between 1.9 and 2.5. In comparison, the corresponding calibrations based on organic C alone had an error from 11.7 to 28.2 kg N ha-1 and RPDs from 1.3 to 2.5. In three of four annual calibrations within a field, the NIR-based calibrations worked better than the organic C based calibrations. The prediction of N-uptake across years, but within a field, worked slightly better with an organic C based calibration than with a NIR based one, RPD = 1.9 and 1.7 respectively. Across fields, the corresponding difference was large in favour of the NIR-calibration, RPD = 2.5 for the NIR-calibration and 1.5 for the organic C calibration. It was concluded that NIR-spectroscopy integrates information about organic C with other relevant soil components and therefore has a good potential to predict complex functions of soils such as N-mineralization. A relatively good agreement of spectral relationships to parameters related to the N-mineralization of datasets across the world suggests that more general models can be calibrated

    Effective three-band model for double perovskites

    Full text link
    We start from a six-band model describing the transition-metal t2g orbitals of half-metallic double perovskite systems, such as Sr2FeMoO6, in which only one of the transition metal ions (Fe) contains important intratomic repulsion Ufe. By eliminating the Mo orbitals using a low-energy reduction similar to that used in the cuprates, we construct a Hamiltonian which contains only effective t2g Fe orbitals. This allows to treat exactly Ufe, and most of the Fe-Mo hopping. As an application, we treat the effective Hamiltonian in the slave-boson mean-field approximation and calculate the position of the metal-insulator transition and other quantities as a function of pressure or on-site energy difference.Comment: 8 pages, 3 figure
    • 

    corecore