606 research outputs found

    Comparison of student nurses' expectations and newly qualified nurses' experiences regarding clinical practice: A secondary analysis of a cross-sectional survey.

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    To compare student nurses' expectations and newly qualified nurses' experiences regarding clinical practice in Switzerland 1 year after graduation. A secondary explorative analysis of a cross-sectional survey. The data were sourced from the Swiss National Graduate Survey of Health Professionals covering six universities of applied sciences between 2016 and 2019, with information on three cohorts of bachelor student nurses, with a 1-year follow-up between each year. The participants were 533 bachelor-prepared nursing graduates. The student nurses' overall expectations included the following top two prioritized aspects: 'contributing to something important' and 'adequate time to spend with patients'. Newly graduated nurses' clinical practice experiences demonstrated that not all expectations were met 1 year after graduation. The largest gaps were found in 'adequate time to spend with patients', 'work-life balance' and experiencing 'good management'. The most crucial expectation gaps are related to having sufficient time to spend with patients and a good work-life balance. The most important result is whether there is a shortage of places for nurses to work rather than the oft-cited shortage of nurses. The expectations of Swiss newly qualified nurses can be better met by an assessment in the first year about which individual perceptions of workplace characteristics cause them to make choices to change something about their work, affect their job satisfaction or influence their intention to stay. Few of the student nurses' expectations were met 1 year after graduation, therefore Swiss healthcare institutions should improve needs assessments to strengthen the nurse workforce starting early in employment. The results underscore the importance of a constructive management culture, such as that in magnet hospitals in the United States which underpins the philosophy of changing in nursing. The results can be used internationally as a benchmark and as a basis for introducing potential interventions for nurse retention. This study was reported following the Standardized Reporting of Secondary Data Analyses Checklist. There were no patient or public contributions. This study has not been registered

    Phenomenological template family for black-hole coalescence waveforms

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    Recent progress in numerical relativity has enabled us to model the non-perturbative merger phase of the binary black-hole coalescence problem. Based on these results, we propose a phenomenological family of waveforms which can model the inspiral, merger, and ring-down stages of black hole coalescence. We also construct a template bank using this family of waveforms and discuss its implementation in the search for signatures of gravitational waves produced by black-hole coalescences in the data of ground-based interferometers. This template bank might enable us to extend the present inspiral searches to higher-mass binary black-hole systems, i.e., systems with total mass greater than about 80 solar masses, thereby increasing the reach of the current generation of ground-based detectors.Comment: Minor changes, Submitted to Class. Quantum Grav. (Proc. GWDAW11

    Betreuungsindex in Pflegeheimen: Entwicklung und Validierung eines neuen Instruments zur Beurteilung von Betreuungsqualität in Pflegeheimen

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    Zusammenfassung: Hintergrund: Derzeit gibt es in der Literatur kein geeignetes Instrument zur Beurteilung der Betreuungsqualität in Pflegeheimen. Die Autoren haben deshalb ein neues Instrument, den Betreuungsindex in Pflegeheimen (Nursing Home Care Index, NCI), konzipiert und getestet. Material und Methode: Betreuungsqualität wird in der Literatur in 8Dimensionen definiert. Es wurde ein Fragebogen mit 42Fragen aus 12validierten Messinstrumenten entwickelt. Der Originalfragebogen wurde mit 320Mitarbeitern aus 15Alteneinrichtungen getestet. Die Daten wurden mithilfe einer Faktorenanalyse und Cronbachsα untersucht und auf 3Faktoren und 16Fragen reduziert. Das revidierte Instrument wurde in einer weiteren Studie mit 136Mitarbeitern auf seine Anwendbarkeit überprüft. Ergebnisse: Als Ergebnis der Faktorenanalyse konnten 16Items mit einer 3-Faktoren-Struktur, d.h. soziale Teilhabe, emotionales Wohlbefinden und Selbstbestimmung, identifiziert werden. Diese 3Faktoren erklären 51,2% der Gesamtvarianz. Die Reliabilität der Gesamtskala beträgt 0,87, die der 3Subskalen Selbstbestimmung 0,86, emotionales Wohlbefinden 0,71 und soziale Beziehungen bzw. Teilhabe 0,78. Die Gesamtpunktezahl des NCI erlaubt eine Kategorisierung der Betreuungsqualität in den 3Abstufungen gut, ausreichend und dringender Verbesserungsbedarf. Schlussfolgerungen: Der NCI hat eine doppelte Funktion. Einerseits dient er Mitarbeitern und dem Heimmanagement als internes Qualitätssicherungsinstrument. Andererseits könnte es zukünftig Angehörigen von potenziellen Heimbewohnern die Möglichkeit bieten, die Betreuungsqualität verschiedener Pflegeheime zu vergleiche

    Beam Test of Silicon Strip Sensors for the ZEUS Micro Vertex Detector

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    For the HERA upgrade, the ZEUS experiment has designed and installed a high precision Micro Vertex Detector (MVD) using single sided micro-strip sensors with capacitive charge division. The sensors have a readout pitch of 120 microns, with five intermediate strips (20 micron strip pitch). An extensive test program has been carried out at the DESY-II testbeam facility. In this paper we describe the setup developed to test the ZEUS MVD sensors and the results obtained on both irradiated and non-irradiated single sided micro-strip detectors with rectangular and trapezoidal geometries. The performances of the sensors coupled to the readout electronics (HELIX chip, version 2.2) have been studied in detail, achieving a good description by a Monte Carlo simulation. Measurements of the position resolution as a function of the angle of incidence are presented, focusing in particular on the comparison between standard and newly developed reconstruction algorithms.Comment: 41 pages, 21 figures, 2 tables, accepted for publication in NIM

    Binary black hole merger in the extreme mass ratio limit

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    We discuss the transition from quasi-circular inspiral to plunge of a system of two nonrotating black holes of masses m1m_1 and m2m_2 in the extreme mass ratio limit m1m2(m1+m2)2m_1m_2\ll (m_1+m_2)^2. In the spirit of the Effective One Body (EOB) approach to the general relativistic dynamics of binary systems, the dynamics of the two black hole system is represented in terms of an effective particle of mass μm1m2/(m1+m2)\mu\equiv m_1m_2/(m_1+m_2) moving in a (quasi-)Schwarzschild background of mass Mm1+m2M\equiv m_1+m_2 and submitted to an O(μ){\cal O}(\mu) radiation reaction force defined by Pad\'e resumming high-order Post-Newtonian results. We then complete this approach by numerically computing, \`a la Regge-Wheeler-Zerilli, the gravitational radiation emitted by such a particle. Several tests of the numerical procedure are presented. We focus on gravitational waveforms and the related energy and angular momentum losses. We view this work as a contribution to the matching between analytical and numerical methods within an EOB-type framework.Comment: 14 pages, six figures. Revised version. To appear in the CQG special issue based around New Frontiers in Numerical Relativity conference, Golm (Germany), July 17-21 200

    Simulation of Binary Black Hole Spacetimes with a Harmonic Evolution Scheme

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    A numerical solution scheme for the Einstein field equations based on generalized harmonic coordinates is described, focusing on details not provided before in the literature and that are of particular relevance to the binary black hole problem. This includes demonstrations of the effectiveness of constraint damping, and how the time slicing can be controlled through the use of a source function evolution equation. In addition, some results from an ongoing study of binary black hole coalescence, where the black holes are formed via scalar field collapse, are shown. Scalar fields offer a convenient route to exploring certain aspects of black hole interactions, and one interesting, though tentative suggestion from this early study is that behavior reminiscent of "zoom-whirl" orbits in particle trajectories is also present in the merger of equal mass, non-spinning binaries, with appropriately fine-tuned initial conditions.Comment: 16 pages, 14 figures; replaced with published versio

    Towards absorbing outer boundaries in General Relativity

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    We construct exact solutions to the Bianchi equations on a flat spacetime background. When the constraints are satisfied, these solutions represent in- and outgoing linearized gravitational radiation. We then consider the Bianchi equations on a subset of flat spacetime of the form [0,T] x B_R, where B_R is a ball of radius R, and analyze different kinds of boundary conditions on \partial B_R. Our main results are: i) We give an explicit analytic example showing that boundary conditions obtained from freezing the incoming characteristic fields to their initial values are not compatible with the constraints. ii) With the help of the exact solutions constructed, we determine the amount of artificial reflection of gravitational radiation from constraint-preserving boundary conditions which freeze the Weyl scalar Psi_0 to its initial value. For monochromatic radiation with wave number k and arbitrary angular momentum number l >= 2, the amount of reflection decays as 1/(kR)^4 for large kR. iii) For each L >= 2, we construct new local constraint-preserving boundary conditions which perfectly absorb linearized radiation with l <= L. (iv) We generalize our analysis to a weakly curved background of mass M, and compute first order corrections in M/R to the reflection coefficients for quadrupolar odd-parity radiation. For our new boundary condition with L=2, the reflection coefficient is smaller than the one for the freezing Psi_0 boundary condition by a factor of M/R for kR > 1.04. Implications of these results for numerical simulations of binary black holes on finite domains are discussed.Comment: minor revisions, 30 pages, 6 figure

    Gauge conditions for long-term numerical black hole evolutions without excision

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    Numerical relativity has faced the problem that standard 3+1 simulations of black hole spacetimes without singularity excision and with singularity avoiding lapse and vanishing shift fail after an evolution time of around 30-40M due to the so-called slice stretching. We discuss lapse and shift conditions for the non-excision case that effectively cure slice stretching and allow run times of 1000M and more.Comment: 19 pages, 14 figures, REVTeX, Added a missing Acknowledgmen

    Highly efficient polymer solar cells cast from non-halogenated xylene/anisaldehyde solution

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    Several high performance polymer:fullerene bulk-heterojunction photo-active layers, deposited from the non-halogenated solvents o-xylene or anisole in combination with the eco-compatible additive p-anisaldehyde, are investigated. The respective solar cells yield excellent power conversion efficiencies up to 9.5%, outperforming reference devices deposited from the commonly used halogenated chlorobenzene/1,8-diiodooctane solvent/additive combination. The impact of the processing solvent on the bulk-heterojunction properties is exemplified on solar cells comprising benzodithiophene-thienothiophene co-polymers and functionalized fullerenes (PTB7:PC71BM). The additive p-anisaldehyde improves film formation, enhances polymer order, reduces fullerene agglomeration and shows high volatility, thereby positively affecting layer deposition, improving charge carrier extraction and reducing drying time, the latter being crucial for future large area roll-to-roll device fabrication. © The Royal Society of Chemistry 2015

    Are moving punctures equivalent to moving black holes?

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    When simulating the inspiral and coalescence of a binary black-hole system, special care needs to be taken in handling the singularities. Two main techniques are used in numerical-relativity simulations: A first and more traditional one ``excises'' a spatial neighbourhood of the singularity from the numerical grid on each spacelike hypersurface. A second and more recent one, instead, begins with a ``puncture'' solution and then evolves the full 3-metric, including the singular point. In the continuum limit, excision is justified by the light-cone structure of the Einstein equations and, in practice, can give accurate numerical solutions when suitable discretizations are used. However, because the field variables are non-differentiable at the puncture, there is no proof that the moving-punctures technique is correct, particularly in the discrete case. To investigate this question we use both techniques to evolve a binary system of equal-mass non-spinning black holes. We compare the evolution of two curvature 4-scalars with proper time along the invariantly-defined worldline midway between the two black holes, using Richardson extrapolation to reduce the influence of finite-difference truncation errors. We find that the excision and moving-punctures evolutions produce the same invariants along that worldline, and thus the same spacetimes throughout that worldline's causal past. This provides convincing evidence that moving-punctures are indeed equivalent to moving black holes.Comment: 4 pages, 3 eps color figures; v2 = major revisions to introduction & conclusions based on referee comments, but no change in analysis or result
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