5,654 research outputs found
International developments in the position of assisting spouses and the possible implications for the Netherlands
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
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 CuâZrâBe bulk metallic glass forming alloys
The compositional dependence of thermal and elastic properties of CuâZrâBe 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
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
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
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 (). 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
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
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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