197 research outputs found

    Health care provision for refugees in Germany – one-year evaluation of an outpatient clinic in an urban emergency accommodation

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    Background: In 2015, Germany recorded the highest rates of refugees since the early 1990s. Access to medical care is a legally regulated fundamental element of aid for refugees. In practice, there are several hurdles such as language barriers and legal regulations. In response to the massively increased need, special outpatient services for refugees were started in several German cities. In Cologne, an outpatient clinic (OPD) was established in the largest emergency accommodation centre for refugees supported by the Cologne municipality and operated by the German Red Cross and physicians from the Association of Statutory Health Insurance Physicians. This study reports experiences of the first year of the OPD regarding structure, processes and utilization. Methods: Employing mixed methods, between May and December 2015 cross sectional pseudonymized data from patients’ contacts were collected, coded in the International Classification of Primary Care (ICPC) and evaluated. Infrastructure, equipment, process organisation and function of the OPD were assessed during five participatory observations and triangulated with results of a self-administered questionnaire for staff and four qualitative interviews with key informants. Results: During the observation period a total of 2205 persons (67% male) stayed in the emergency accommodation and 984 patient contacts (51% male) were registered, mainly by young persons from Western Balkan countries and Syria. Medical treatment was sought primarily for acute respiratory-, loco-motor-system- and skin symptoms followed by chronic physical diseases. Headache, back and neck pain and acute respiratory infection were the most frequent diagnoses. Questionnaires and interviews among staff revealed language barriers and psycho-trauma as the most frequently reported challenges. Equipment and staffing was adequate, but patient documentation was not systematic, leading to loss of information. Conclusion: To facilitate refugees’ appropriate access to health care, the OPD was seen as functional for this refugee accommodation centre. Need was recognised for standardized, data protective documentation and a health passport for clients for medical information. Psychological support for refugees needs expansion taking legal circumstances and coverage of costs into consideration. To improve patient communication employees working with refugees should be offered an introduction to culturally sensitive understanding of health and illness

    Effect of the strong metal-support interaction on hydrogen sorption kinetics of Pd-capped switchable mirrors

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    The morphology and electronic structure of Pd clusters grown on oxidized yttrium surfaces are investigated by scanning tunneling microscopy and ultraviolet photoelectron spectroscopy. The hydrogen sorption mediated by the Pd clusters is determined from the optically monitored switching kinetics of the underlying yttrium film. A strong thickness dependence of the hydrogen uptake is found. The electronic structure of the as-grown Pd clusters depends only weakly on their size. Strong changes of the photoemission spectra are found after hydrogenation, in particular the oxide peak shifts and the Pd peaks vanish. Both phenomena are due to a strong metal-support interaction (SMSI) state, characterized by a complete encapsulation of the clusters by a reduced yttrium oxide layer. Scanning tunneling spectroscopy confirms the SMSI state of small Pd clusters after hydrogen exposure. The SMSI effect is less important with increasing Pd thickness. This explains the critical thickness for the catalyzed hydrogen uptake by the Pd/Y

    Ultrafast modulation of electronic structure by coherent phonon excitations

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    Femtosecond x-ray absorption spectroscopy with a laser-driven high-harmonic source is used to map ultrafast changes of x-ray absorption by femtometer- scale coherent phonon displacements. In LiBH4, displacements along an Ag phonon mode at 10 THz are induced by impulsive Raman excitation and give rise to oscillatory changes of x-ray absorption at the Li K edge. Electron density maps from femtosecond x-ray diffraction data show that the electric field of the pump pulse induces a charge transfer from the BH4− to neighboring Li+ ions, resulting in a differential Coulomb force that drives lattice vibrations in this virtual transition state

    Hydrogen Dynamics in Lightweight Tetrahydroborates

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    The high hydrogen content in complex hydrides such as M[AlH4]x and M[BH4]x (M = Li, Na,K, Mg, Ca) stimulated many research activities to utilize them as hydrogen storage materials. An understanding of the dynamical properties on themolecular level is important to understand and to improve the sorption kinetics. Hydrogen dynamics in complex hydrides comprise long range translational diffusion as well as localized motions like vibrations, librations or rotations. All the different motions are characterized by their specific length- and timescales. Within this review we give an introduction to the physical properties of lightweight complex hydrides and illustrate the huge variety of dynamical phenomena on selected example

    Development of improved nickel catalysts for sorption enhanced CO2 methanation

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    Sorption enhanced CO2 methanation is a complex process in which the key challenge lies in the combined optimization of the catalyst activity and water adsorption properties of the zeolite support. In the present work, improved nickel-based catalysts with an enhanced water uptake capacity were designed and catalytically investigated. Two different zeolite frameworks were considered as supports for nanostructured Ni, and studied with defined operation parameters. 5Ni/13X shows significantly increased, nearly three-fold higher, operation time in the sorption enhanced CO2 methanation mode compared to the reference 5Ni/5A, likely due to its higher water sorption capacity. Both catalysts yield comparable CO2 conversion in conventional CO2 methanation (without water uptake). Regeneration of the catalysts performance is possible via a drying step between methanation cycles under both reducing and oxidizing atmospheres; however, operation time of 5Ni/13X increases further after drying under air

    Structural and optical properties of Mg<sub>x</sub>Al<sub>1-x</sub>H<sub>y</sub> gradient thin films: a combinatorial approach

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    The structural, optical and dc electrical properties of MgxAl1-x (0.2≀x≀0.9) gradient thin films covered with Pd/Mg are investigated before and after exposure to hydrogen. We use hydrogenography, a novel high-throughput optical technique, to map simultaneously all the hydride forming compositions and the kinetics thereof in the gradient thin film. Metallic Mg in the MgxAl1-x layer undergoes a metal-to-semiconductor transition and MgH₂ is formed for all Mg fractions x investigated. The presence of an amorphous Mg-Al phase in the thin film phase diagram enhances strongly the kinetics of hydrogenation. In the Al-rich part of the film, a complex H-induced segregation of MgH₂ and Al occurs. This uncommon large-scale segregation is evidenced by metal and hydrogen profiling using Rutherford backscattering spectrometry and resonant nuclear analysis based on the reaction ÂčH(Âč⁔N,αγ)ÂčÂČC. Besides MgH₂, an additional semiconducting phase is found by electrical conductivity measurements around an atomic [Al]/[Mg] ratio of 2 (x=0.33). This suggests that the film is partially transformed into Mg(AlH₄)₂ at around this composition

    Functionalised metal-organic frameworks: a novel approach to stabilising single metal atoms

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    We have investigated the potential of metal-organic frameworks for immobilising single atoms of transition metals using a model system of Pd supported on NH2-MIL-101(Cr). Our Transmission Electron Microscopy and in-situ Raman spectroscopy results give evidence for the first time that functionalised metal-organic frameworks may support, isolate and stabilise single atoms of palladium. Using Thermal Desorption Spectroscopy we were able to evaluate the proportion of single Pd atoms. Furthermore, in a combined theoretical-experimental approach, we show that the H-H bonds in a H2 molecule elongate by over 15% through the formation of a complex with single atoms of Pd. Such deformation would affect any hydrogenation reaction and thus the single atoms supported on metal-organic frameworks may become promising single atom catalysts in the future

    Optical properties of MgH2 measured in situ in a novel gas cell for ellipsometry/spectrophotometry

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    The dielectric properties of alpha-MgH2 are investigated in the photon energy range between 1 and 6.5 eV. For this purpose, a novel sample configuration and experimental setup are developed that allow both optical transmission and ellipsometric measurements of a transparent thin film in equilibrium with hydrogen. We show that alpha-MgH2 is a transparent, colour neutral insulator with a band gap of 5.6 +/- 0.1 eV. It has an intrinsic transparency of about 80% over the whole visible spectrum. The dielectric function found in this work confirms very recent band structure calculations using the GW approximation by Alford and Chou [J.A. Alford and M.Y. Chou (unpublished)]. As Pd is used as a cap layer we report also the optical properties of PdHx thin films.Comment: REVTeX4, 15 pages, 12 figures, 5 table

    Investigation of a Pt containing washcoat on SiC foam for hydrogen combustion applications

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    A commercial Pt based washcoat, used for catalytic methane combustion, was studied supported on a commercial SiC foam as catalytic material (Pt/SiC) for catalytic hydrogen combustion (CHC). Structural and chemical characterization was performed using Electron Microscopy, X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS). The reaction was monitored following water concentration by Fourier Transform Infrared spectra (FTIR). The FTIR method was compared with H2 detection by Gas Cromatography (GC) and has shown to be adequate to study the kinetics of the CHC reaction in steady state under our experimental conditions (very lean 1% (v/v) H2/air mixtures). The catalyst is composed of 5–20 nm disperse Pt nanoparticles decorating a mixture of high surface area Al2O3 and small amounts of ceria supported on the SiC foam which also contains alumina as binder. The Pt/SiC catalytic material has demonstrated to be active enough to start up the reaction in a few seconds at room temperature. The material has been able to convert at least 18.5 Lhydrogen min−1 gPt−1 at room temperature in conditions of excess of catalyst. The Pt/SiC material was studied after use using XPS and no significant changes on Pt oxidation states were found. The material was characterized from a kinetic point of view. From the conversion-temperature plot a T50 (temperature for 50% conversion) of 34 °C was obtained. Activation energy measured in our conditions was 35 ± 1 kJ mol−1.Peer reviewe
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