5,654 research outputs found

    International developments in the position of assisting spouses and the possible implications for the Netherlands

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    Vergelijking van de situatie van meewerkende vrouwen in Nederland en de overige lidstaten van de Europese Unie. Aandacht wordt besteed aan ontwikkelingen op Europees en Nederlands niveau en de formele erkenning, die onder te verdelen is in professionele erkenning, financiële erkenning, participatieve en representatieve erkenning, en administratieve erkenning.

    Searching for optimal variables in real multivariate stochastic data

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    By implementing a recent technique for the determination of stochastic eigendirections of two coupled stochastic variables, we investigate the evolution of fluctuations of NO2 concentrations at two monitoring stations in the city of Lisbon, Portugal. We analyze the stochastic part of the measurements recorded at the monitoring stations by means of a method where the two concentrations are considered as stochastic variables evolving according to a system of coupled stochastic differential equations. Analysis of their structure allows for transforming the set of measured variables to a set of derived variables, one of them with reduced stochasticity. For the specific case of NO2 concentration measures, the set of derived variables are well approximated by a global rotation of the original set of measured variables. We conclude that the stochastic sources at each station are independent from each other and typically have amplitudes of the order of the deterministic contributions. Such findings show significant limitations when predicting such quantities. Still, we briefly discuss how predictive power can be increased in general in the light of our methods

    Thermal and elastic properties of Cu–Zr–Be bulk metallic glass forming alloys

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    The compositional dependence of thermal and elastic properties of Cu–Zr–Be ternary bulk metallic glass forming alloys was systematically studied. There exists a linear relationship between the glass transition temperature Tg and the total Zr concentration. G decreases linearly with increasing Zr concentration as well. The results also show that Tg, shear modulus G, and Poisson's ratio nu are very sensitive to changes in compositions. Low Tg, low G, and relatively high nu can be achieved with high Zr and Ti concentration

    Health and safety at work: the implication of the Council Directive on enterprises in Europe

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    Bedrijven zijn verplicht een risico-analyse en risico-evaluatie voor de arbeidsomstandigheden uit te voeren. Veel meer grote bedrijven dan kleine bedrijven in Europa doen dit daadwerkelijk. Terwijl in Europa zeven van de tien grote bedrijven een risico-analyse uitvoeren, doen niet meer dan twee op tien kleine bedrijven dit. In Nederland is het verschil nog groter, omdat 90% van de grote bedrijven een risico-analyse uitvoert, tegenover 20% van de kleine bedrijven. Dit blijkt uit onderzoek van EIM naar de omgang van ondernemingen met wetgeving op het gebied van arbeidsomstandigheden.

    Superdiffusion of massive particles induced by multi-scale velocity fields

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    We study drag-induced diffusion of massive particles in scale-free velocity fields, where superdiffusive behavior emerges due to the scale-free size distribution of the vortices of the underlying velocity field. The results show qualitative resemblance to what is observed in fluid systems, namely the diffusive exponent for the mean square separation of pairs of particles and the preferential concentration of the particles, both as a function of the response time.Comment: 5 pages, 5 figures. Accepted for publication in EP

    Lithium abundances along the RGB: FLAMES-GIRAFFE spectra of a large sample of low-mass Bulge stars

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    Context: A small number of K-type giants on the red giant branch (RGB) is known to be very rich in lithium (Li). This fact is not accounted for by standard stellar evolution theory. The exact phase and mechanism of Li enrichment is still a matter of debate. Aims: Our goal is to probe the abundance of Li along the RGB, from its base to the tip, to confine Li-rich phases that are supposed to occur on the RGB. Methods: For this end, we obtained medium-resolution spectra with the FLAMES spectrograph at the VLT in GIRAFFE mode for a large sample of 401 low-mass RGB stars located in the Galactic bulge. The Li abundance was measured in the stars with a detectable Li 670.8 nm line by means of spectral synthesis with COMARCS model atmospheres. A new 2MASS (J-K) - Teff calibration from COMARCS models is presented in the Appendix. Results: Thirty-one stars with a detectable Li line were identified, three of which are Li-rich according to the usual criterion (logâĄÏ”(Li)>1.5\log\epsilon({\rm Li})>1.5). The stars are distributed all along the RGB, not concentrated in any particular phase of the red giant evolution (e.g. the luminosity bump or the red clump). The three Li-rich stars are clearly brighter than the luminosity bump and red clump, and do not show any signs of enhanced mass loss. Conclusions: We conclude that the Li enrichment mechanism cannot be restricted to a clearly defined phase of the RGB evolution of low-mass stars (M\sim1M_{\sun}), contrary to earlier suggestions from disk field stars.Comment: 6 pages (14 with appendix), 5 figures (1 in appendix), accepted for publication in A&

    Lithium factories in the Galaxy: novae and AGB stars

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    We review the state of the art in modelling lithium production, through the Cameron-Fowler mechanism, in two stellar sites: during nova explosions and in the envelopes of massive asymptotic giant branch (AGB) stars. We also show preliminary results concerning the computation of lithium yields from super-AGBs, and suggest that super-AGBs of metallicity close to solar may be the most important galactic lithium producers. Finally, we discuss how lithium abundances may help to understand the modalities of formation of the "second generation" stars in globular clusters.Comment: invited review presented at IAU Symposium 267 "Light Elements in the Universe", Geneva, Switzerland, Nov. 9-13 2009, in pres

    Automating HAZOP studies using D-higraphs

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    In this paper, we present the use of D-higraphs to perform HAZOP studies. D-higraphs is a formalism that includes in a single model the functional as well as the structural (ontological) components of any given system. A tool to perform a semi-automatic guided HAZOP study on a process plant is presented. The diagnostic system uses an expert system to predict the behavior modeled using D-higraphs. This work is applied to the study of an industrial case and its results are compared with other similar approaches proposed in previous studies. The analysis shows that the proposed methodology fits its purpose enabling causal reasoning that explains causes and consequences derived from deviations, it also fills some of the gaps and drawbacks existing in previous reported HAZOP assistant tools
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