40 research outputs found
Superconducting phase transition in YNiGe3, a non-f-electron reference to the unconventional superconductor CeNiGe3
A polycrystalline sample of YNiGe3, being a non-magnetic isostructural
counterpart to the unconventional pressure-induced superconductor CeNiGe3, was
studied by means of specific heat and electrical resistivity measurements at
temperatures down to 360 mK and in magnetic fields up to 500 Oe. The compound
was found to exhibit an ambient-pressure superconductivity below Tc = 0.46 K.
The superconducting state in YNiGe3 is destroyed by magnetic field of the order
of 500 Oe.Comment: to appear in Solid State Communication
Single-ion Kondo Scaling of the Coherent Fermi Liquid Regime in Ce1-xLaxNi2Ge2
Thermodynamic and transport properties of the La-diluted Kondo lattice
CeNi2Ge2 were studied in a wide temperature range. The Ce-rich alloys
Ce1-xLaxNi2Ge2 were found to exhibit distinct features of the coherent heavy
Fermi liquid. At intermediate compositions (0.7 <= x <= 0.9) non-Fermi liquid
properties have been observed, followed by the local Fermi liquid behavior in
the dilute limit. The 4f-electron contribution to the specific heat was found
to follow the predictions of the Kondo impurity model both in the local as well
as coherent regimes, with the characteristic Kondo temperature decreasing
rapidly from about 30 K for the parent compound CeNi2Ge2 to about 1K in the
most dilute samples. The specific heat does not show any evidence for the
emergence of a new characteristic energy scale related to the formation of the
coherent Kondo lattice.Comment: to appear in Physical Review Letter
Adequacy of Protein and Energy Intake in Critically Ill Adults Following Liberation From Mechanical Ventilation Is Dependent on Route of Nutrition Delivery
This is the peer reviewed version of the following article: Moisey, L. L., Pikul, J., Keller, H., Yeung, C. Y., Rahman, A., Heyland, D. K., & Mourtzakis, M. (2020). Adequacy of protein and energy intake in critically ill adults following liberation from mechanical ventilation is dependent on route of Nutrition Delivery. Nutrition in Clinical Practice, 36(1), 201–212, which has been published in final form at https://doi.org/10.1002/ncp.10558. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Background: Studies examining nutrition intake of critically ill patients following liberation from mechanical ventilation (LMV) are scarce. The objectives of this prospective, observational feasibility study were to quantify and assess protein and energy intake in hospitalized, critically ill patients following LMV, to determine barriers to optimal intake, and to report on the feasibility of recruiting and retaining patients into this study.
Methods: Adult patients requiring MV for >72 hours in a medical/surgical intensive care unit (ICU) were recruited. Protein and energy intakes were quantified up to 14 days following LMV. Patients also identified barriers to eating.
Results: Nineteen patients (mean age, 60 years [SD, 12 years]) were studied over 125 days. Over all study days, the median amounts of protein and energy consumed in comparison with amounts prescribed by dietitians were 46% (interquartile range [IQR], 26-100) and 71% (IQR, 38-100), respectively. When stratified by route of nutrition delivery, on days (n = 54) when patients consumed an oral diet as the sole nutrition source, median amounts of protein and energy consumed in comparison with those prescribed were only 27% (IQR, 15-41) and 47% (IQR, 29-66), respectively. The most frequently reported barriers to eating were poor appetite, early satiety, and taste changes.
Conclusions: Protein and calorie intake is below prescribed amounts for patients whose enteral nutrition is discontinued and an oral diet prescribed as sole nutrition source following LMV. Acceptable strategies to enhance nutrition intake in post-ICU patients during the recovery stages of critical illness are needed.This research was funded by a research grant from the Canadian Foundation for Dietetic Research. L.L. Moisey was supported by a Canadian Institutes for Health Research Doctoral Research Award
From caged compounds with isolated U atoms to frustrated magnets with 2- or 3-atom clusters: a review of Al-rich uranium aluminides with transition metals
International audienceCrystal structures and physical properties of four families of Al-rich ternary uranium compounds with transition metals () are reviewed, namely UAl, UAl, UAl, and UAl. The compounds can be described as consisting of 1 (isolated), 2 (dumbbells) or 3 (triangles) uranium atom clusters, surrounded (1-2-20, 1-2-10 and 6-4-43) or not (3-4-12) by large cages, which strongly influence their magnetic and related properties. Indeed, the ground states of the described systems evolve from Curie-like paramagnetism in the case of the phases with well-isolated, single U-atoms, to complex magnetic order or possible frustrated magnetism in the case of the systems with uranium triangles forming a breathing kagome lattice. We argue that the four families of uranium aluminides described in this review provide a unique opportunity to study magnetic interactions between U magnetic moments while gradually increasing the number of their nearest magnetic neighbors, and may also be helpful in understanding the fundamental origin of magnetic freezing phenomena
Ferromagnetism in structurally disordered UFe0.39Ge2
International audienceA polycrystalline sample of the uranium ternary germanide UFe0.39Ge2 was examined by means of X-ray powder diffraction, DC magnetization and AC magnetic susceptibility, heat capacity and electrical resistivity measurements performed in wide ranges of temperature and magnetic fields. The experiments confirmed that the compound crystallizes with orthorhombic crystal structure of the CeNiSi2-type that is closely re-lated to that of the ferromagnetic superconductor UGe2 and orders ferromagnetically at 37 K. Moreover, it exhibits some features characteristic of ferromagnetic cluster glasses. The electrical transport in UFe0.39Ge2 is strongly influenced by structural disorder arising from the partly occupied Fe-sites in its crystallographic unit cell. (C) 2021 The Author(s). Published by Elsevier B.V. CC_BY_NC_ND_4.
Hybrid Chlorides with Methylhydrazinium Cation: [CH<sub>3</sub>NH<sub>2</sub>NH<sub>2</sub>]CdCl<sub>3</sub> and Jahn-Teller Distorted [CH<sub>3</sub>NH<sub>2</sub>NH<sub>2</sub>]CuCl<sub>3</sub>
The synthesis, structural, phonon, optical, and magnetic properties of two hybrid organic-inorganic chlorides with monoprotonated methylhydrazinium cations (CH3NH2NH2+, MHy+), [CH3NH2NH2]CdCl3 (MHyCdCl3), and [CH3NH2NH2]CuCl3 (MHyCuCl3), are reported. In contrast to previously reported MHyMIICl3 (MII = Mn2+, Ni2+, and Co2+) analogues, neither compound undergoes phase transitions. The MHyCuCl3 has a crystal structure familiar to previous crystals composed of edge-shared 1D chains of the [CuCl5N] octahedra. MHyCuCl3 crystallizes in monoclinic P21/c symmetry with MHy+ cations directly linked to the Cu2+ ions. The MHyCdCl3 analogue crystallizes in lower triclinic symmetry with zig-zag chains of the edge-shared [CdCl6] octahedra. The absence of phase transitions is investigated and discussed. It is connected with slightly stronger hydrogen bonding between cations and the copper–chloride chains in MHyCuCl3 due to the strong Jahn–Teller effect causing the octahedra to elongate, resulting in a better fit of cations in the accessible space between chains. The absence of structural transformation in MHyCdCl3 is due to intermolecular hydrogen bonding between two neighboring MHy+ cations, which has never been reported for MHy+-based hybrid halides. Optical investigations revealed that the bandgaps in Cu2+ and Cd2+ analogues are 2.62 and 5.57 eV, respectively. Magnetic tests indicated that MHyCuCl3 has smeared antiferromagnetic ordering at 4.8 K
Superconductivity in high-entropy alloy system containing Th
Abstract Th-containing superconducting high entropy system with the nominal composition (NbTa) 0.67 (MoWTh) 0.33 was synthesized. Its structural and physical properties were investigated by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, specific heat, resistivity and magnetic measurements. Two main phases of alloy were observed: major bcc structure and minor fcc. The experimental results were supported by numerical simulation by the DFT Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA)
Magnetic, electric and thermoelectric properties of ternary intermetallics from the Ce-Co-Ge system
International audienceMagnetic susceptibility, magnetization, electrical resistivity and thermoelectric power of polycrystalline Ce2CoGe3, Ce3CoGe2, CeCo0.86Ge2, Ce5Co4Ge13, CeCoGe3, and Ce2Co3Ge5 were studied in wide temperature and magnetic field ranges. The results of magnetic properties and electrical resistivity measurements carried out for Ce3CoGe2, CeCo0.86Ge2, CeCoGe3 and Ce2Co3Ge5 corroborate the data reported in literature. Ce2CoGe3 and Ce5Co4Ge13 were found to be ferromagnetically ordered below 10 and 7Ă‚Â K, respectively. Moreover, the resistivity of Ce2CoGe3 shows Kondo-like behavior. The thermoelectric power exhibits in all six phases a large broad maximum, located between 50 and 150Ă‚Â K, most likely due to the presence of 4f electrons